发布时间：
让你大修最起码给了你一次机会，只要你老老实实回答审稿人的意见就有录用的机会，而且基本上让你大修就成功了一半了北京译顶科技价格比较合理，我就是在那边做的，没花多少钱 加速查下。
当需要将中文文献引用到英文论文中时，直接在网上搜索中文文献相应的英语摘要，导入文献管理软件进行引用即可。
在SCI期刊中，大部分是英文期刊，可以说发表sci论文，在引用参考文献上，应优先考虑英文参考文献，尽量不引用中文参考文献，但这不代表sci论文不可以引用中文参考文献。毕竟有很多原创的科研成果是在中文期刊上发表的，是被认可的。
SCI论文中中文文献的注意事项
1、引用的参考文献要忠实于原文
参考文献，即是对该文献的借鉴和参考，我们要在保留原文献的理论中进行借鉴，作者无权更改原作者的本意，只需向读者介绍原作者使用的方法、得出的结果和结论等。作者可以对原作者使用的方法、得出的结果和结论等发表看法，但不能肆意更改，不管是故意的，还是无意的。
2、尽量选用原始文献
我们很多人也许有这样的经历，写文章前，都会查阅大量与自己论文研究相关的综述。因此在写文章时也会引用大量综述论文。其实我们在做研究看文献时，都希望看到原始文献。
3、应注意参考文献的著录格式
因参考文献的著录格式各刊不尽相同，投稿前作者应注意杂志的有关规定，至少得先看看有关期刊发表的论文的参考文献是如何标注的，以了解有关期刊的参考文献的著录格式，以免出错。许多作者投递的稿件书写格式包括参考文献的著录格式与杂志所要求的不同。
参考资料来源：百度百科——SCI
中文文献如果有英文版翻译的话以出版的英文翻译为准，没有的话就自己翻符合语法就行。作者用拼音，重点是格式吧，参考文献的格式是要求最重要的。
英文学术文献翻译的软件有很多，罗列后分为以下三个类型：
根据泛读→精读→学习英语
第一类是需要泛读英文文献材料，就需要一个软件能够大段大段的翻译，这个时候不要求翻译的一个精准度，只要求能够大概的意思能够翻译到位，不要把专业词汇翻译成口语化的词汇就行。这一类一般常用的知云文献翻译，一篇文献它可以给你广泛性的进行翻译，可以初步的对摘要进行一个整体的了解，来判断这篇文献是不是符合要求。
第二类是精读的时候往往需要去对其中某一段的意思，做一个详细的翻译。这个时候推荐百度翻译、谷歌翻译和欧路词典结合，百度翻译能翻译出一些学术性的词汇，但是对一些你特别想要了解的词汇，还是需要借助词典来进行补充，也非常适合你平时想在iPad上面进行学习和翻译。
第三类是精读的同时还希望能够把不认识的单词都给记录下来，一般用的是一个插件Burning Vocabulary，这个插件可以在网页上把不认识的单词通过双击给你展示出来，然后你可以复制在自己的word里头，甚至可以导入到不背单词里头进行学习。
无人超市代表着我们和机器人的关系越来越近了，而我们的生活也越来越便利了，不过不好的就是工作的岗位也变少了。
无人超市的兴起，背后蕴含着新消费时代的商业判断：又一次零售革命可能正加速到来。
从百货商店到连锁商店再到大型超市，尽管零售的本质始终是围绕效率、成本与体验的“买买买”，但基于消费变革与技术变革，“零售基础设施”一直在变。随着电子商务的到来，信息、商品与资金的流动效率一直在升级，消费者的习惯和品位也在不断变化。
就国内而言，从顺丰“嘿客”到沃尔玛和京东合作，打通线上与线下的努力一直在进行。而日本大型超市衰落，便利店挺进乡村，中国一些精品超市遇冷等现象，也未尝不是零售业变革的脚注。
无人超市技术发展：
技术对商业的推动作用可能是决定性的。无人超市之所以可能，主要是摸到了技术监管的“钥匙”，这离不开人脸识别、手脉识别、4G网络、移动支付等技术的发展。高科技在场，让购物者如入无人之境，却又处处走不出“电子围栏”。
比如在亚马逊无人超市，当你拿起架上的货品，APP上购物车里就会相应增加此物，一旦放回，购物车立马自动减去。
这种科技感，既能让交易“不闻不问”，又构成了商品价值以外的体验价值。应该说，“无人”并非新概念，街头自动贩卖机即是，但无人超市的最大卖点是全新的购物场景，而购物场景的多元化，恰恰被行业人士预言为新消费时代的趋势。
以上内容参考：人民网——人民日报人民时评：无人超市会开启消费新时代吗
可以试点，但个人不看好，国家应该加征重税！多少普通家庭靠开小超市赖以为生，大家去自己小区周边转转就知道了！淘宝的崛起是因为给广大民众带来了实惠和便利，但无人超市只会给整个社会带来大量失业！这个问题解决不好，会带来严重的社会问题！
学会计的不容易啊，我当年也是学会计的，毕业论文确实头疼了好久，现在的话接触会计行业不多了，不过给你点建议还时可以的。首先看你的知道老师是什么专业 的，这一点非常非常重要的，然后呢，看他们年岁大不大，如果是年龄偏大的老师，你的论文就要偏向专业，有鲜明主题的那种了，如果你的老师也是年轻人，你就可以在论文中谈谈你对新行业会计的认知。1、对工业企业会计来进行分析，你看工业行业，技术，管理，人才筛选方面都比较的严格。阐述自己对工业企业的弊端，新财务的实用性和适用性。2、对市场新型商业行业进行财务分析，新型金融行业，新型贸易行业，新型的仓储行业。比如老马的无人超市，你就可以来进行分析。3、书上的知识始终只纸上，你可以把理论和实践的重要性来谈论。4、电算化会计的到来，会让一部分会计失业，这个观点你也可以把控。5、未来的话会计主要还是偏向于管理，财务管理，税务规划是你们以后发展的重点，虽然人们说会计都无聊枯燥，但是你一旦高度上升，所看到的学到的就足可以傲视群雄了。给了你几条建议，这时我大学的时候论文方向，不知道现在过时了没有，如果还可以参考，那我就没有白写了。。。只能给你个建议方向，剩下的就看你们自己的了。
超市存货量对超市经营产生较大的影响，这是因为超市存货价值比较大，在流动资产中的占比相对而言也比较大。下面是我为大家整理的超市存货管理论文，供大家参考。
[摘要] 随着零售市场的 发展 ，中小型超市的急剧扩张，各个连锁超市在日益激烈的竞争中，为了寻求发展，增加利润率，提升 企业 竞争力，越来越关注其库存 管理。存货管理促进了超市管理，最佳的存货水平可以降低企业存货资金的占用，加速存货资金的周转，增强盘点的管理水平，促进企业的降低成本提高企业 经济 效益。 文章 剖析中小型超市存货管理中的弊端，探讨加强中小型超市存货管理的途径。
[关键词] 中小型超市存货管理资金周转经济效益
超市企业存货是指企业在日常活动中持有以备出售的产成品或商品等。超市应加强存货的管理与核算，一方面避免存货过多而积压资金，另一方面又要避免缺货的威胁， 影响 企业的资金周转，影响企业经济效益的提高。超市存货管理就是要满足消费者的需求，在商品、时机、场合、价格和数量等互相配合的情况下，真正达到流通的目的。
一、存货管理的重要性
超市企业的存货在流动资产中占比重非常大，存货价值直接影响着流动资产价值，正确反映存货价值，对于客观、公允的反映流动资产价值、反映企业财务状况、经营成果都有着重要的意义。
1.存货的管理水平，促进超市提升竞争能力。存货管理水平直接影响着超市产品的质量、产品定价、加班时间、剩余生产能力、交付周期以及超市的整体的获利能力等方面因素，甚至影响到对顾客的需求能否做出迅速反应的能力，存货管理水平的高低直接关系到超市能否成为一个强有力的竞争主体的关键。
2.较好的库存管理，促使超市加速存货周转。所谓存货周转就是对暂时未卖出的货架上的产品依据先进先出的原则进行循环。存货管理主要是为了加速存货周转，存货周转又促进存货管理水平的提高。存货周转分为前线存货和后备存货的周转。前线存货是指陈列在货架或者零售商购物 环境处的散装商品;后备存货指的是存放在仓库内的用于补货的货物。存货周转要求销售人员、理货人员及时向客户的货架上补充货物，保证货架里面的产品陈列符合标准、保证客户提供给消费者的产品永远是最新生产日期的产品、永远是新鲜的。存货周转直接刺激销售，较好的库存管理，促使超市加速存货周转。
二、中小型超市存货管理 问题 与原因
通过对北京市中小型超市调研与 分析 归纳中小型超市存货管理中主要存在以下问题：
1.缺乏经常性的实地盘存制，存货的盘盈、盘亏、积压、毁损等 会计 信息不能及时反映出来，影响了会计报表的真实性。由于企业销售或耗用成本是倒算出来的，这样就容易把在计量、收发、保管中产生的差错，甚至任意挥霍浪费、非法盗用等，全部计入销售成本或耗用成本，同时不便于对存货进行随时控制。
2.存货的收入、发出、结存的会计记录不完整。
3.存货数量的虚假不实。小规模超市经常是租赁一间单元房来办公，存货要放到数个与办公地点不同的“仓库”。在注册会计师预先通知小规模企业将要前往的监盘地点的情况下，小规模企业得以有充分的时间将存货做调整转移。小规模企业之所以可以隐瞒存货短缺是因为已得知注册会计师将要检查哪些地点的存货，小规模企业有充足的时间把该地点放满存货，造成存货数量的虚假不实。
4.存货的监盘者缺乏 经验 ，不能识别出残次冷背的存货。存货监盘有其局限性，存货监盘只能对实物资产是否确实存在提供有力的证据，但不能保证被监盘(或被 审计)单位对监盘的存货资产拥有所有权，并且也不能对该资产的价值提供审计证据。
5.存货储存的弊端：超市持有一定数量的库存是必要的，但是过量的库存将造成不必要的费用，超市的商品一旦入库，便面临着如何尽快销售出去的问题。存货储存会给企业造成较多的资金占用费(如利息成本或机会成本)和仓储管理费。因此，尽量缩短存货储存时间，加速存货周转，是节约资金占用，降低成本费用，提高企业获利水平的重要 方法 和保证。
三、探讨加强中小企业超市存货管理的途径
1.加速存货周转提高库存管理水平。存货周转是销售人员、理货人员重要职责，是提供给消费者永远是最新生产日期的产品的重要保证。
(1)销售人员根据超市的规定和标准及时更换不良品，对客户的存货进行管理，努力做客户的专业顾问，主动为客户提供全面的存货管理服务，而不仅仅只是“接订单”。要做到这一点，销售人员必须做到：对超市的产品知识掌握全面，例如保质期、代码的意义、产品存放的条件等。再比如，将产品放在太阳直照的地方会退色，进而影响品质，不易卖出。
(2)销售人员必须了解各种包装的适用范围和库存量的多少。也就是通过了解消费者和客户的需求，了解各种品牌、包装的知识、向客户推荐正确的包装和品牌的产品组合，这是保证客户正在销售符合消费者需求的产品，进行客户管理的前提条件。
(3)要深刻理解存货周转的三项原则，即动手周转货架上的陈列产品、落实先进先出的原则、把存货数记入客户卡。
(4)讲究存货周转方法与技巧。销售人员应具备商品学知识，了解经营和空间上的限制条件，抓住一切合作和促进业绩提升的机会;设定产品保质期、储存条件、消费者购买的最佳时机;各种包装的适用范围和库存量的熟悉可以帮助销售人员判断不同零售商执行的分销标准以及根据该零售商的出货情况设定合适的库存数量;预测机会可以帮助销售人员更加理性地思考问题并提前考虑到一些影响生意的因素提高销售量。
2.建立健全实物资产管理的岗位责任制度。超市企业应当建立实物资产管理的岗位责任制度，对实物资产的验收入库、领用、发出、盘点、保管及处置等关键环节进行控制，防止各种实物资产被盗、毁损和流失。对存货等重要资产的控制以保证资产的安全完整。如对有关重要资产或记录的存放地安装和使用防盗、防火的报警设施等以防被盗或遭受损失等，以确保其安全与完整，对重要的文件和会计记录还应进行合理的档案管理以保护实物安全。
3.实施盘点控制。盘点控制是指通过对企业的资产实施定期或不定期盘点清查，并将盘点结果与会计记录进行比较以确定其是否相符，进而发挥控制作用的一种控制方法。超市应根据自身的特点建立资产盘点制度：
(1)定期盘点。
(2)盘点人员组成。针对不同的资产，确定盘点人员。由资产保管人员、记录人员、内部查账人员、单位或得到授权部门的负责人员共同组成盘点小组，以确保盘点结果的客观、准确。
(3)盘点手续。盘点前，应做好各项准备 工作，包括盘点表、盘点器具的准备，盘点具体时间的安排等;盘点过程中，应合理分工，确定操作人员、监视人员、复查人员职责。
(4)盘点结果的处理。通过对盘点结果的抽查，确保盘点结果的相对准确，并对盘点所查明的问题应得到有关部门的核准进行调整处理。
4.发挥审计人员作用，对存货进行键盘。期末存货的结存数量直接影响到会计报表上的存货金额。对期末存货数量的确定，是存货审计中的重要 内容 。审计人员对存货进行键盘是存货审计中重要审计工作。
(1)参与存货实地盘点的规划。审计人员应该会同企业制定盘点 计划，一方面可以使企业更加了解审计对存货盘点的要求，另一方面也有利于审计人员掌握企业存货管理的情况和企业对存货盘点的初步安排。
(2)盘点问卷调查。 审计人员在实地观察存货盘点前，应对 企业 存货盘点的 组织与准备 工作进行调查，以确定企业是否按照盘点 计划的要求进行盘点的准备工作。
(3)实地观察与抽点。盘点开始时，审计人员应该亲临盘点现场，密切关注企业的盘点现场以及盘点人员的操作程序和盘点过程。审计人员应注意观察盘点现场的存货是否摆放有序并停止流动，盘点人员的盘点程序是否符合盘点计划和指令的基本要求，计量器具是否准确，有无重计或漏计错误，盘点标签或盘点清单是否安要求填制。如果发现 问题 ，审计人员应及时指出并监督企业更正。
(4)撰写盘点备忘录，编制审计工作底稿。盘点工作结束后，审计人员应根据存货的盘点情况，撰写盘点备忘录，对盘点程序，盘点中的重大问题及处理、盘点结果等予以记载，并连同企业的盘点计划或指令、盘点表，问卷调查资料以及所取得的其他资料一起整理成工作底稿。
5.零库存 管理政策，是企业市场竞争的重要武器。在企业生产中，库存是由于无法预测未来需要变化，而又要保持不间断的生产经营活动必须配置的资源。但是，过量的库存会诱发 企业管理 中诸多问题，例如资金周转慢、产品积压等。因此很多企业往往认为，如果在采购、生产、 物流、销售等经营活动中能够实现零库存，企业管理中的大部分问题都会随之解决。零库存便成了生产企业管理中一个不懈追求的目标。所谓零库存是指物料(包括原材料、半成品和产成品等)在采购、生产、销售、配送等一个或几个经营环节中，不以仓库存储的形式存在，而均是处于周转的状态。零库存，一方面使成品和原材料降价迅速的风险和损失;另一方面也实现了成本降低，企业效益最大化，促进企业提升竞争能力。由迈克尔·戴尔创立的戴尔 计算 机超市 目前 已成为全球领先的 计算机系统直销商，跻身业内主要制造商之首。2004年年度财务 报告 可知，该超市产品销售量、销售额、净收入和每股收益等方面均创世界新高，成为全球增长最快的计算机超市。在美国，戴尔是商业用户、政府部门、 教育 机构和个人消费者市场名列第一的计算机供应商。在竞争日趋激烈的计算机制造行业，戴尔取得如此骄人的业绩，可以说是零库存管理模式立下了汗马功劳。
综上所述，存货管理促进了超市管理，最佳的存货水平降低企业存货资金的占用，加速存货资金的周转，增强盘点的管理水平，促进企业的降低成本提高企业 经济 效益。
[摘要]煤矿生产项目的开展，需要一系列配套的基础设施，以保证煤矿各个生产环节在有序的状态下进行。文章从这个角度出发，首先分析了煤矿井口建立物资超市的必要性，对于当前物资超市的效能和工作流程进行了分析，在此基础上探究物资超市供存货管理模式，突出介绍了该模式存在的优势，希望可以将其推广到更加广泛的地区进行运用。
[关键词]物资超市;超市管理模式;供存货管理
煤矿井口物资超市是以服务生产为出发点和落脚点而建立的，不仅能够给予日常生产工作各种材料资源，成为各项资源的集散区域，而且是实现物资超市供存货信息收集和整理的地方，由此实现对于物资供存货管理工作的调整和改善。因此，探究物资超市供存货管理问题，显得尤为必要。
1 煤矿井口建立物资超市的必要性
对于多数煤矿企业而言都成立了专门的供应科，建立了大型的物料存放仓库，甚至形成了对应的用料二级库，但是在实际生产物料服务的过程中，上述部门并没有发挥其效能，出现了各个方位各尽其职，缺乏监督，使得物料出现大量浪费的情况，由此使得单位的物资成本处于较高的状态。显然，在当前煤矿生产市场竞争激烈的背景下，这样传统的物资管理模式是不符合当前生产发展需求的，因此就有必要尝试以全新的方式去进行管理和控制。
煤矿井口物资超市就是在生产区域附近建立起来的，专门服务于生产，为其提供材料，保证生产所需的各种物资是能够满足需求的，避免因为物资供应不上造成生产环节停滞。具体来讲，这种物资超市的工作流程为：首先，派遣物资管理人员对于物资进行调拨，货物到达超市的时候，超市管理人员需要对物资的数量进行清点，并且做好收货签字。其次，生产队组负责人凭借领料单去领取物资，井口超市管理人员实现领料单的收集和整理，并且将其递交给物资管理人员，物资管理人员凭借这些信息实现出库手续的办理。另外超市管理人员实现对于库存的盘点，结合施工工序环节，明确所需的物资，对于物资管理部门提出补充物资的要求，并且在每月的月底对于超市物资进行清点，以书面和电子信息的方式进行录入。
显然这种井口物资超市的建立是很有必要的：其一，有利于改变原来古老低效率的物资管理组织格局，实现了各项管理资源的整合，最大限度地实现了资金储备率的降低;其二，符合当前统一化管理的基本原则，遵循了市场化运作的规律，并且推动物资管理朝着标准化的方向发展和进步;其三，极大程度地便利了生产基层单位，使得生产的过程得以精简，生产服务的水平得以不断提升;其四，废除二级库物资管理的模式，以创新的物资管理模式来进行，符合煤炭企业现代化发展的基本要求，对于提升煤炭企业整体管理水平来讲，是至关重要的。
2 煤矿井口物资超市供存货管理的策略
煤矿井口物资超市的建立，在改变煤矿生产的物资管理模式方面发挥着积极作用。但是实际上煤矿井口物资超市供存货管理效能的发挥，还需要积极做好以下几个方面的工作。
注重对于煤矿物资管理现状的调查和研究
煤矿物资超市的构建，需要对煤矿物资管理工作进行全面的调查和研究，只有充分了解煤矿物资管理工作的缺陷和不足，才能知道如何更加高效地构建煤矿物资超市，切实地发挥物资超市在供存货管理方面的最大价值。为此，笔者建议应该积极做好几个方面的工作：其一，邀请同行煤炭企业的物资管理经验丰富的专家，集合企业内部在此方面经验丰富的职员，矿长，生产队队长，供应科成员，财务部成员，企业管理部门成员，形成煤矿物资管理调研团队，从经济性和可行性多个角度对煤矿物资管理工作的问题进行归纳 总结 ;其二，要求从数据方面对于当前煤矿物资管理的问题进行分析，并且对于建立物资超市可能实现的物资成本降低数据进行预测，由此给予决策者更加直观的物资超市构建效益，为制定物资超市的构建方案打下信息基础。
制定科学合理的井口物资超市的筹建方案
物资超市的筹建方案，不仅奠定了物资超市效能实现的基本格局，还是影响其供存货管理效能发挥的前提和基础。因此，保证井口物资超市筹建方案是科学的、合理的，是很值得去探究的问题。一般来讲，在确定方案合理性的过程中，应该高度重视几个方面工作的开展：其一，做好煤矿井口地质情况的调查，根据后期实际生产环节规划方案，一般会在井口和副井口之间的距离建立对应的物资超市，保证后期物资超市能够服务于整个生产环节;其二，从形成的角度对物资超市的便捷性进行分析，保证最大限度的便捷生产，使得其物料供应的价值得到最大化的发挥;其三，物资超市构建方案除了要考量其后期效能的发挥，还需要将超市管理人员的日常工作考虑进去，保证其能够在理想的环境下进行各项物资管理工作，也是我们需要积极思考的。比如，给予其设置专门的工作台，保证物资供应管理工作的效益和质量。
注重对于井口物资超市各种物资设备的投入
物资超市的建立需要投入对应的硬件设备，这是保证物资超市供存货管理效能发挥的前提和基础。因此在此方面也应该注重管控，笔者认为需要注意几个环节的工作：其一，制定煤矿物资超市构建的基本物资设备标准和规范，将其作为奖励物资超市的依据，使得井口物资超市物资设备的投入是符合各项要求的;其二，注重对于超市构建的硬件投入，建立健全完善的超市货架设备，从稳固性和安全性多个角度对其进行质量检查，保证其后期效能的实现;其三，保证物资超市面积的合理性，实现对应配套设施的完善，并且制定明确的物资超市设备管理规范和制度，实现对于超市管理人员行为的监督和管理。
实现物资超市供存货管理流程的标准管理
前面提及物资超市供存货管理流程要朝着标准化和规范化的方向发展，这是最大化发挥物资超市在供存货管理方面效能的关键所在。对此，应该着手做好几个方面的工作：其一，实现与同行企业之间的合作，考察已经纳入物资超市的企业，对于其已经成文的物资超市供存货管理流程进行学习和研究，结合自身煤矿生产的实际情况，因地制宜地实现对应管理规范的调整和改善;其二，在日常的物资超市管理效能发挥的过程中，不断总结其中的管理缺陷和不足，积极实现对于现有管理制度和规范的调整和改善，以保证其与实际供存货管理的需求是一致的;其三，坚持与时俱进的基本原则，定期对物资超市供存货管理流程进行价值分析，以找到其中的管理漏洞，以便采取对应 措施 来改善调整。相信随着上述几个步骤的开展，物资超市供存货管理的制度将会不断完善和调整，由此发挥更大的效能。
3 结 论
综上所述，以物资超市建立的方式，实现煤矿供存货管理模式的创新，的确能够在实现生产成本降低，促进物资管理工作效益和质量提升方面发挥积极作用。尤其在当前煤矿生产企业之间竞争趋势加强的背景下，积极引入物资超市供存货管理新模式，的确可以形成全新的煤矿企业核心竞争能力，由此引导煤矿生产朝着标准化、现代化的方向发展和进步。相信随着煤炭企业越来越意识到物资超市的价值，就会积极在此方面加大投入，由此切实发挥其在物资超市供存货管理方面的效能。
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摘要：存货作为企业的重要流动资产之一，它直接关系到企业的资金占用水平以及资产运作效率。存货管理的好坏会影响到整个企业及企业相关者的利益，因此必须重视存货管理。本文就存货管理进行分析，提出加强存货管理的途径。
关键词：存货;存货管理;内部控制
一、存货管理的内涵
存货是指企业在日常活动中持有以备出售的产成品或商品、处在生产过程中的在产品、在生产过程或提供劳务过程中耗用的材料、物料等。其区别于非流动资产最基本的特征是，持有存货的最终目的是为了出售。
存货管理就是对企业的存货进行管理，主要包括存货的信息管理和在此基础上的决策分析，最后进行有效控制，达到存货管理的最终目的――提高经济效益。
二、存货管理的重要性
(一)企业正常运行的前提条件。企业为了保证生产经营过程的持续，会有计划地购入、耗费和销售存货，它是供产销环节中必不可缺少的资产，也是保证生产经营活动持续进行的必要条件。
(二)提高企业经济效益的有效途径。企业应当通过正确的存货管理方式，分析并查明企业存货占用不合理及形成积压的原因，以便采取合理措施控制存货储备，降低资金占用水平，提高存货的流转速度，最终达到企业经济效益提高的效果。
三、目前企业存货管理存在的主要问题
(一)存货管理理念不健全。缺乏全面供应链成本理念。企业往往只重视运输、仓储、采购成本等显性成本，而对于机会成本损失、物流管理成本、库存持有成本等隐性成本重视不够。企业采购、生产、销售等部门间协调困难，扯皮、推诿现象严重。另外，企业内部没有建立完善的存货管理制度，或者已建立但缺乏有效的考核和监督，使之不能良好地运行，造成内部资源的浪费，同时也增加了存货流转过程中营私舞弊的可能性，使存货的监管效率低下。
(二)存货内部控制薄弱。有的企业将存货采购、保管、验收都兼于一人，由同一个人完成采购销售、付款收款、入库出库等全过程，势必会造成管理人员的徇私舞弊。部分家族式企业，还会出现管理职位形同虚设且缺乏对相关制度的认可，在雇佣员工时，常会选择亲戚朋友，对其专业知识没有过多要求，进而不能对存货质量进行严格的验收，必定存在不如同行业产品质量的问题，不利于企业长远发展。
(三)存货账实不符。在采购环节，企业购入的材料已经领用消耗，但购货发票未到，期末没有暂估入库，甚至出现红字余额;在领用环节，材料已经领用消耗，而实际上并未相应结转成本或者材料并未领用消耗;在入库环节，完工产品已入库，但并没有相应的账簿登记;在销售环节，实现销售时，由于保管人员没有及时记录，导致相关会计人员不能够对销售收入作及时的处理，没有按实际销售收入结转库存产成品，形成大量的账外资金，导致存货账面与库存数额不一致，造成账实不符。
四、提升企业存货管理的途径
(一)建立全面的供应链成本理念。企业经营管理者层必须重视存货的管理，对于物流管理成本、库存持有成本、机会成本损失等隐性成本应该足够重视。在日常工作中，要主动加强对会计准则中关于存货管理制度的学习，要积极参加 财务管理 知识的培训，努力提高存货管理的意识和水平。企业内部形成良好的存货管理环境，从而为存货管理提供保障。
优化存货管理除了需要企业管理层改变经营理念、重视存货管理外，还应该让企业的采购、仓库、财务、生产和销售等各个部门均参与到存货管理中，共享存货管理的相关信息，通过内部资源的整合来提高存货管理的效率。在整合的过程中，企业应当将存货管理的理念灌输给每一个员工，强调企业全员参与存货管理，为存货的管理创造良好的氛围。
(二)完善企业内部控制体系。企业必须要重视存货管理的各个环节，在采购、验收、仓储、领用、销售、付款的各个环节，根据企业自身情况，合理安排专业人员进行管理。首先，企业要建立严格的内部稽核制度。通过建立存货管理岗位责任制，明确相关人员应承担的责任、权利和义务，规范存货管理的各个环节，确保相关部门和 岗位职责 分明，并保证存货管理的不相容岗位相互分离、相互制约和监督，杜绝徇私舞弊现象的发生;其次，建立定期和不定期的存货盘点制度，实施盘点控制。企业应对存货进行定期和不定期的盘点清查，以确定账实是否相符，为企业的存货管理提供真实可靠的信息;第三，建立并完善供应商准入制度。企业应建立完整的供应商档案，根据供应商的生产能力、资质等级、信誉及价格等情况，建立完整的供应商准入制度，从源头上制止不良存货的发生。
(三)加强存货管理信息化系统建设。企业应结合自身业务流程特点，采用与之相配套的存货管理软件，建立企业的存货管理信息系统，实现企业存货资源信息化统一管理、数据共享，有效阻止与存货相关部门的各自为政、信息阻塞、账实不符、随意性强等现象的发生，从而提高企业的存货管理效率。
充分利用ERP等先进的管理模式，使人、财、物、供、产、销全方位科学高效集中管理，最大限度地堵塞漏洞，降低库存，使存货管理更上一个新台阶，实现存货资金信息化管理。
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前言 超市需要处理大量的库存信息，还要时刻更新产品的销售信息，不断添加商品信息。面对不同种类的信息，需要合理的数据库结构来保存数据信息，需要有效的程序结构支持各种数据操作的执行。商店自动化的产品管理在欧美等国家早已经实现，也是零售业管理的基础。它最主要的特点是能够实时的和准确的控制店内的销售情况。如果可以能够实时掌握销售流程及销售情况，则可以有效地加速商品的周转率并提高服务质量，而且可以减少产品售价不符等所产生的问题。顾客的消费要求的是希望在超市购物中能基本上都能购得所需的商品，并且还要既保证商品质量还要享受优质，方便的服务。 摘要 随着小超市规模的发展不断扩大，商品数量急剧增加，有关商品的各种信息量也成倍增长。超市时时刻刻都需要对商品各种信息进行统计分析。而大型的超市管理系统功能过于强大而造成操作繁琐降低了小超市的工作效率。 超市管理系统是市场上最流行的超市上常用的系统之一，它主要包含以下几个模块：系统权限的设定、原始数据录入、数据的汇总及查询等。从而，实现对进货、销售及员工信息等实现全面、动态、及时的管理。 本文系统的分析了软件开发的背景以过程；首先介绍了软件的开发环境，其次介绍了本软件的详细设计过程：数据库的设计、各个模块的设计和实现，以及具体界面的设计和功能。 关键词：超市 管理信息系统 第一章 绪论 社会背景 随着现代科学技术的迅猛发展，计算机技术已经渗透到哥哥领域，成为各行业必不可少的工具，特别是Internet技术的推广和信息高速公路的建立，使IT产业在市场竞争中越发显示出其独特的优势，步入信息化时代，有巨大的数据信息等待加工处理和传输，这使得对书数据库的进一步开发和利用显得尤为迫切。 作为国内市场的一些中小型超市，它们在信息化过程中的步伐要落后于大中型超市，而对于这些企业的资源管理，信息的存储和处理也显得迫切需要，要适应市场竞争，就需要有高效的处理方式和管理方法，因此加快超市的信息化进程是必可少的。 实习期间，我们通过对市场的调查，针对现在各中小型超市对经营业务和人事管理的实际需要，开发了这套超市管理系统。在开发过程中，我们针对当前各超市管理的特点和技术人员的实际水平，采用基于Windows图形用户界面这一易学易用的操作环境，在系统设计过程中，我们尽量采用易懂易读的人机界面，使用户可以在短期内完全掌握。我们又始终发系统的正确性放在首位，力求数据的完整和处理的正确性。在此基础上优化程序代码，加速系统运行和减少对系统资源的占用。 查看原文：
随着我国经济的快速发展和 商业模式 的不断创新，连锁经营管理专业也越来越热门。下面是我为大家整理的连锁经营管理专业 毕业 论文，供大家参考。 连锁经营管理专业毕业论文篇一：《高职连锁经营管理人才培养》 摘要：随着我国企业连锁经营模式的发展，行业对连锁经营管理人才的需求急剧增加。高等职业 教育 承担起了培养各类高素质技能型人才的任务。为缓解社会对连锁经营管理人才的渴求，探索其人才培养体系就成了该专业建设的当务之急。本文从高职连锁经营管理专业人才培养定位，课程体系设计的内在逻辑，专业核心能力与课程体系建设， 教学 方法 与模式等四个方面探讨了连锁经营管理专业人才培养体系的构建。 关键词：高职教育;连锁经营管理;人才培养;体系研究 连锁经营管理专业在我国高职院校专业设置中出现得相对较晚，1999年才被教育部正式添加到高职专业目录里。专业设置较晚并不代表连锁经营这种现代商业模式的发展滞后，随着中国经济实力的不断提升与发展，连锁企业如同雨后春笋般的涌现出来。据统计，我国“十五”期间全国连锁企业的门店数量就高达十万多家，营业额达到7000亿元。“十一五”期间，中国百强连锁企业店铺增长率平均高达51%。“十二五”期间，中国整体经济环境进一步繁荣，连锁经营企业再一次迎来了发展机遇。根据《2011—2015年中国连锁经营行业投资分析及前景预测 报告 》显示，到2010年底百强连锁企业门店数量就已经达到15万多个，销售额增长至万亿元。从另一个角度看，连锁企业如此迅猛的发展也必将带来数量巨大的就业岗位，连锁经营管理人才已经出现稀缺态势。正因为如此，本着高等职业教育“肩负着培养面向生产、建设、服务、管理第一线需要的高技能人才的使命。”探索高职连锁经营管理专业人才培养体系就势在必行了。 一、连锁经营管理专业人才培养定位 企业连锁经营商业模式起源于美国，这种经营理念从它诞生之日起就受到了各界的关注，后来风靡全球，在我国也得到了快速的发展。所谓连锁经营是指企业在不同的多个区域里，以统一的名称，统一的标志，统一的管理方法，统一的服务程序等进行商业运营的模式。这种经营模式突出了品牌效应，因此而获得了营销上的优势，给商家带来了巨大的经济效益。高职类专业的特点源于行业本身的特点，换而言之，现代连锁经营模式有什么样的特性，高职院校所开设的此专业就必须依据这种特性展开教学和实训，只有如此才能真正培养出能胜任连锁经营管理一线工作的高素质技能型人才。连锁经营企业的运营主要分为三大板块——连锁企业总部的运营管理，连锁企业门店的运营管理，连锁企业的商品物流管理。这三大板块又分别在内部组织系统，信息技术系统，风险控制系统，统筹规划系统等四大管理框架下完成连锁经营。正因为有了上述连锁经营行业的特性，连锁经营管理专业的特点也因此而彰显出来。高职教育连锁经营管理专业人才培养的目标也就清晰明了了：培养具备一定的连锁经营管理专业理论，适应连锁零售管理与服务一线需要，掌握连锁门店运营管理操作技术，能从事门店开发，胜任商品采购、品类管理、物流配送、卖场设计、商品促销等连锁经营一线的高素质技能型人才。 二、连锁经营管理专业课程体系设置的内在逻辑 高职教育体系下的专业课程体系设置应本着属于它的规律进行。高职教育是以服务社会为宗旨，以学生就业为导向，以发展地方区域经济为思路，以培养专业核心能力为原则而构建起来的课程体系群。设置高职教育专业课程体系，我们需要理清一条逻辑线路：所设专业的就业方向是什么?→在此方向上有哪些岗位群?→每一个岗位群里又有哪些具体的岗位?→每一个岗位的工作任务是什么?→胜任每一个具体的岗位需要哪些专业能力?→每一种专业能力需要哪些课程来支撑?如果我们能回答这条逻辑线路上的每一个问题，那么专业课程体系的设置也就呼之欲出了。连锁经营管理专业课程体系如何设置?我们本着上面的逻辑线路依次进行。连锁经营管理专业的就业方向是从事连锁企业一线服务与管理工作。在此方向上有四个岗位群，连锁总部管理岗位群，连锁门店运营管理岗位群，物流管理岗位群，配送管理岗位群。在这四个岗位群里，有初始岗位9个，例如市场调研员、收银员、理货员、质量管理专员，物流专员等等。有可发展岗位8个，例如连锁门店店长、物流配送主管，品类主管等等。还有相关岗位11个，例如行政管理， 市场营销 ， 人力资源管理 等等。每一个岗位都它的工作任务，例如市场调研岗，其工作任务就是信息收集、问卷调查、问题研究以及组织项目调查活动的各类协调工作。在这样的工作岗位上，要完成此项任务，工作人员就必须具备市场调研能力，分析问题的能力，设计问卷调查的能力，人际沟通与协调能力。这些能力从何而来呢，就需要课程来支持。要构建这些能力就必须开设《 市场调查 与预测》、《市场营销学基础》、《消费者行为学》等课程。按照这样的思路与方式，连锁经营管理专业的课程设置也就建立起来了。 三、连锁经营管理专业核心能力与课程框架 根据企业连锁经营就业方向和相关岗位要求，从事连锁经营管理工作需要具备以下五个方面的能力：市场调研与分析能力，门店开发与运营能力，经营策划与设计能力，商务洽谈与沟通能力，商品物流与管理能力。在这五个方面的能力中有三种能力是连锁经营管理所必须具备的核心能力，它们是门店开发与设计能力，商品采购与管理能力，门店运用与管理能力。在学科领域里，专业核心能力往往是此专业区别于彼专业的差别与特点，也是构建专业核心课程的理论依据。要具备门店开发与设计能力，在课程上就需要有《经济学基础》、《市场调查与预测》、《连锁门店开发与设计》等课程来支持。要具备商品采购与管理能力，在课程上就需要有《商品学基础》、《物流基础》、《品类管理与实务》等课程来支持。要具备门店运营与管理能力，在课程上就需要有《消费者心理学》、《连锁企业信息管理系统》、《会计基础》、《连锁企业人力资源管理》等课程来支持。需要注意的是，专业核心能力的形成绝非几门专业核心课的教授就能让学生达到的，换而言之，核心能力除了专业核心课程的支撑以外还要有 其它 公共课和专业基础课来夯实基底，才能真正打造出该专业的核心竞争能力。对于连锁经营管理专业核心能力的打造需要有三个层次的目标来完成，分别是知识目标、能力目标、和素质目标。在知识目标层面，要懂得管理学原理，经济学基础、会计学基础、物流基础的相关知识。了解国家对连锁经营管理方面的政策与法规。要理解消费者心理与消费购买决策的过程。懂得商品学的基础知识，熟悉商品采购过程。掌握理货员、收银员、店长等岗位的职责。在能力目标层面，要有清晰的语言表达与沟通能力，有一定的英语应用能力，有计算机实际操作能力，有问卷调查和市场开拓能力，有商品采购和物流配送的能力，有理货、收银、盘点的能力，有卖场设计能力，有处理顾客投诉及危机公关能力，有人力协调，员工管理能力。在素养目标层面，要具有一定的中国人文艺术修养，具有良好的身体素质和心理素质，热爱自己的事业，遵守行业规范，能积极工作，乐观向上。 四、连锁经营管理专业教学方法与模式 我国高职教育培养的是高素质技能型人才，这一定位的本身就注定高职教育是重实践教学的。对于连锁经营管理专业的教学方法与模式，我们采用理论与实践相结合的教学方法，以校企合作与工学结合的模式进行专业人才培养，以双证融通的方式进行考核。所谓理论与实践相结合的教学方法，是指教师课堂讲授专业理论，然后通过校内实训室进行相关专业能力的模拟实训。所谓校企合作与工学结合，是指学院努力开拓校外实训基地，通过企业与学院的合作让学生到真实的工作岗位和环境中锻炼，以此增强学生的动手能力和实际操作能力。所谓双证融通的考核方式，是指学生要完成专业理论学习后获得毕业证书，通过校内外实训取得相应岗位的职业资格证书后方能正式毕业。连锁经营管理专业人才培养体系设置是一个动态的过程，动态的根源是行业的变化以及相应岗位能力要求的提升，所以高职教育人才培养体系的探索是一个有起点而没有终点的研究过程。 参考文献： [1]刘轶宏，阎惠全，王晓娟.高职连锁经营管理专业“QSQ三位一体”课程体系的构建与实施[J].中国成人教育，2011(2). [2]孔美多.高职连锁经营管理专业实践教学研究[J].现代商贸工业，2009(17). [3]黄蕾.连锁经营管理人才培养模式的探索与实践[J].中小 企业管理 与科技，2012(1). [4]晋淑惠，王化冰.连锁经营管理专业人才培养方案的研究[J].价值工程，2010(10). [5]高皖秋.论连锁经营管理专业校企合作教育模式改革[J].学理论，2013(35). 连锁经营管理专业毕业论文篇二：《浅谈人才培养下连锁经营管理》 摘要：综上所述，“订单式”培养模式，既符合教育部高职教育的办学思想，也是强化实践性教学的有益尝试，值得深化。 关键词：人才培养;连锁经营管理 一、强化师资队伍建设，建成素质较高的1+N专兼职结合的教师团队 第一，对于青年教师，明确“高职教育不是学科本位而是能力本位教育”的教学指导思想，坚持对新分配工作的青年教师必须取得相关企业工作 经验 后方可执教的原则。 第二，通过选拔方式确定骨干教师，并轮流选派到国内外同类院校考察学习、参与完成课题及企业应用性服务项目;有计划地安排教师到企业挂职锻炼、主持或参加专业应用性项目研究，使其通过在企业一线的工作经历提高自身的双师素质。 第三，坚持发展构建专兼职结合的教师队伍。兼职教师是非常重要的队伍，是学校和社会联系的桥梁，是进行产学研结合的纽带，也是学院未来新专业的增长点。 二、“产学结合、双线并行”的“订单式”人才培养模式的实施 自2008年以来，学院的连锁经营管理专业先后与多家连锁企业进行合作，开展联合培养，校企共建世纪联华、苏宁电器等多个“订单班”。经过多年的调研论证及运行，针对连锁经营管理专业的学生培养要求，结合商业零售业季节周期性特点，正式构建并实施“订单式”人才培养模式。经过几年的探索发展，连锁经营管理专业订单班管理机制已非常全面，但在管理效率上还有一些提升空间。具体如下： 第一，企业学校共同制定培养方案。在实际的校企合作中，天津交通职业学院的“订单”培养倾向于“技术型”而非“经营管理型”。因此，合作企业也有责任参与制定学生的培养定位，共同制定注重以学生为本的人才培养方式。 第二，企业学校共同提升“订单班”学生管理效率。在“订单班”运行过程中，应配置指导专业指导教师负责组织管理方面的工作，并采用“半脱产”方式，结合连锁经营管理专业现状，在院系的具体指导和支持下，十分顺利。由于“订单班”所必需的稳定性，“订单”学生的管理工作是十分辛苦的，相对于普通毕业班的辅导工作多出近1倍的工作量。为班主任配置一定比例的绩效奖励，可提高班主任的工作积极性，降低风险，促进“订单”培养的发展完善。 第三，坚持促成学生轮岗学习实践。“订单班”运行过程中，学生轮岗学习实践对维持实习稳定及与企业进行长久合作有重要的现实意义，但学生轮岗学习不宜协调。对企业而言，学生往往安置在多个门店，比较分散，全体轮岗学习操作难度很大，大多数情况下并不现实。对学院而言，学生的工作表现也要防止学生“走马观花，混实习”。不过，给表现优秀的实习生更多的发展机会，是学校和企业都关心的问题。通过与企业多次研讨，与企业共同为学生制订了《轮岗学习办法》并在今后的合作中积极兑现轮岗承诺。尽管如此，在诸多客观因素面前，轮岗实习的推动还是有一定困难的。综上所述，“订单式”培养模式，既符合教育部高职教育的办学思想，也是强化实践性教学的有益尝试，值得深化。 参考文献 1、构建连锁经营管理专业实践教学模式新思路王晓兰;中国成人教育2008-08-30 2、连锁经营管理专业能力结构和实践技能培养方式探讨岑丽阳;商讯商业经济文荟2006-08-20 连锁经营管理专业毕业论文篇三：《浅谈连锁超市经营管理策略》 摘要:当前中国零售业已呈强劲的扩张趋势，在国外超市巨头纷纷登陆时，笔者认为可以通过差异化策略、细分化策略、信息化策略来综合提高我国连锁超市的竞争实力。 关键词:连锁超市经营管理差异化策略细分化策略信息化策略 近代连锁经营自20世纪90年代初引进中国以来，与超级市场的业态形式紧密联系在一起，获得了长足的发展。与目前我国连锁超市主要表现出的经营规模普遍偏小、规范化管理水平不高、业态优势不明显等一系列竞争实力不强的现状极不适应。笔者认为可以通过以下策略增强连锁超市市场竞争力。 一、差异化策略 连锁超市通过差异化策略，来塑造与众不同的特色企业形象。具有鲜明个性的差异化可以通过三点:一是通过 企业 文化 、企业服务等形成企业品牌优势。1.服务个性化：例如河南许昌的胖东来连锁超市通过免费停车，免费市内电话，免费修裤边，免费擦鞋等一系列促销服务来全面提高顾客满意度。2.经销产品的差异化：即在新产品采购与开发上满足顾客的差异需求。3.定牌产品的差异化：例如相同的品牌有不同的样式、价位，可选择较低价的，让顾客觉得这个超市的产品就是便宜从而增加顾客回头率。二是及早抢占有利的地形，店址优势往往具有垄断性，并在长期内难以被突破。较早确定在老百姓心中核心商圈地位。三是寻求业态形式上的差异，采取多种业态经营的方式，如网上订货与送货相结合的服务方式。 二、细分化策略 由于超市具有百货店规模大、品种多和连锁店毛利低、周转快的特点，经营者必须在把握超市经营的具体环境及自身特点的基础上，通过市场细分，对连锁超市进行科学定位，这是成功经营竞争中取胜的关键。 1.综合化发展同时进行区域定位、品类定位 区域定位是以空间为基础的最传统的定位方式，主要是从地理意义上确定目标市场即明确商圈的范围及商圈内顾客的类型、消费特征、购买期望等，并据此安排店铺的布局规模定位。选择不同的区域定位，目标市场不同进行营销活动也应采取不同的定位方式。 品类定位可分为迎头定位和避强定位，首位迎头定位通常适合市场挑战者，这是一种与竞争者针锋相对的定位方式。而避强定位是一种避开强劲竞争对手的市场定位方式，企业可以通过市场分析寻找未被重视或未被控制的市场。 2.专业化发展同步展开连锁超市经营定位战略 (1)消费者定位战略。所谓目标市场定位战略，是指根据超市所在地域即商圈内的顾客的类型及消费需求、购买行为特点，结合超市自身特点，确定超市的服务对象。从超市的基本社会经济功能来看，超市最为基本的目标市场是商圈内的家庭主妇。据调查2012年很多奢饰品及日化品的消费者为男性。随着超市经营品种的增加，经营规模的扩大，超市的服务对象往往呈现出扩大的趋势。 (2)商品定位战略。连锁超市是以经营食品为主的零售店，经营的商品多为日常必需的便利品和非耐用消费品。从经营品种上看，超市的经营品种应当十分齐全，能够满足附近居民80%-90%的日常需求，以满足其一次购齐和挑选的要求。 (3)价格定位战略。价格低廉是超市经营定位战略的一个基本方面。低廉的商品价格不仅对中低收入阶层有吸引力，对高收入阶层同样具有很大的吸引力。同时，超市独特的管理方式、销售方式，又为实行低价策略提供了可行性。 (4)服务定位战略。超市服务定位的核心是顾客在自选的原则下，超市的服务定位可以有自身的特色，根据顾客的需要开发和推出若干服务项目，如采取全天候24小时营业、提供商品信息、开展生活咨询等等。 (5)促销定位战略。连锁超市的促销定位战略的基本战略意图是，通过开展积极有效的促销活动，刺激和诱导消费者的购买行为，从而促进商品销售，提高超市的经营业绩。超市可以采取的促销战略主要有:会员制促梢、折扣促销、特价促销、 广告 促销、有奖促梢、卖场促销、服务促销等。 三、信息化策略 1.电子信息化技术为连锁超市提供了信息管理的先进手段 随着连锁超市规模的不断扩大和市场竞争力的增加，企业越来越需要电子信息化整体的运营管理。采用先进的信息管理手段，运用计算机管理系统与网络相结合，可以使连锁超市在经营中生成信息、保证原始数据完整、准确地采集、传递、实时处理和反馈，极大的提高连锁超市的经营效率。电子信息化技术及超市整体信息化系统对提升连锁超市的市场竞争力的影响在于：一是最大限度地解决大规模经营带来的信息不畅;二是可以全面监控经营活动的每一个环节;三是优化商品经营结构;四是缩短顾客结算时间;五是降低人工成本。 2.实体超市与网上超市相结合，发挥促销优势 现在连锁超市与网络结合成为大趋势，电话购物、网上购物已成为年轻人购物的首选，又为连锁超市节省了人力资源成本。利于整合多种促销手段,效果好且成本相对较低。实体超市与网上超市相结合，与实体超市有所不同的是连锁超市还需要组织建立网络销售平台、配送中心、网络配送站。超市建立的网络平台主要负责销售，配送中心主要是完成货物的采购、配送任务。网络配送站一边接受配送中心来货一边向消费者配送商品,与消费者直接见面,具有配送、宣传、咨询、和收集客户信息的作用。实体连锁超市经常都是区域化的客户、物流相结合，客户 爱好 易于把握、短距离物流降低进货和销售成本,成本下降从而零售价格比较低。目前很多网络平台如淘宝网、京东商城等购物网，整个消费过程方便,售后服务较好，这将会为实体超市带来很大的竞争力。 在以上策略综合使用的同时，为了增加竞争力，我国连锁超市还应该严格建立区域化和低成本优势，健全标准化规范化管理，创建服务品牌企业。 参考文献: [1] 李丹.我国超市业的发展战略研究[J].对外经济贸易大学MBA学位论文，2003年4月 [2] 陈凌.我国未来超市发展之初探[J].中国商贸，2009(5):29-30 [3] 毛鹏举.网上超市的区域化战略评析[J].重庆工商大学学报，2004,4,64-67 猜你喜欢： 1. 连锁经营管理学习心得体会 2. 连锁经营管理学习心得 3. 浅谈企业经营管理毕业论文范文 4. 连锁经营管理心得体会 5. 餐饮业经营管理论文
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Creating a brilliant Beijing: Time for Action Ladies and Gentlemen: My topic is on creating a brilliant Beijing: Time for Action 2008 is such a common number, but many Chinese will get excited when they mention it. How can a common number attract such a strange fascination? The answer is simple and obvious: the twenty-ninth Olympic Game will be held in Beijing in the year 2008. At that time, the whole world will focus their attentions on Beijing. As the hostess, Beijing will show her beauty to the guests from all over the world. The Beijing Olympic Games will be a Green Olympic, a high technology Olympic, and a people's Olympic. Among them, a Green Olympic is the most important concept. It will show the world the determination, the ability, and the confidence of the Chinese people and their government to successfully hold a Green Olympic. To achieve such a goal, however, it needs a lot of hard work. As middle school students in Beijing, we should take on more responsibilities for our capital city's environment. Any action we take will affect the appearance of the city. Therefore, we should start with ourselves, act now, and make every possible effort. But how? You may ask. There are a lot of things we can do in our daily lives. We all know the fact that Beijing is frequently assaulted by sand storms every year. Forests and lands have been degraded by agricultural and industrial activities. To revive those desert lands is beyond our ability, but we can plant trees around our schools or in our neighborhood communities. If everybody does so, there will be a green Beijing and we will have a Green Olympic. I don't know whether you've noticed that some students don't want to walk to school; their parents have to drive them to school every day. But nowadays, the air is polluted with automobile exhausts. What can we do about it? Ride on your bike to school and enjoy exercise! It will not only have significant benefits for your health, but also help improving our environment. In addition, if you don't drive cars, you will not go to the car wash. That will save large amount of water. If everybody does something, there will be a green Beijing and we will have a Green Olympic. Think it over, my friends. The things we can do are definitely not unrealistic. Although we cannot provide with a clean energy source, achieve a better sewage treatment system, or stop any industry from using hazardous chemicals and releasing hazardous wastes, we can save every drop of water and protect every patch of green. Make Beijing a more beautiful city, where green patches are everywhere and blue sky can be seen clearly above our heads. A Green Beijing Olympic is asking for action. Act now. Thank you!
Starting a new book is a risk, just like falling in love. You have to commit to it. You open the pages knowing a little bit about it maybe, from the back or from a blurb on the front. But who knows, right? Those bits and pieces aren’t always right. Sometimes people advertise themselves as one thing and then when you get deep into it you realize that they’re something completely different. Either there was some good marketing attached to a terrible book, or the story was only explained in a superficial way and once you reach the middle of the book, you realize there’s so much more to this book than anyone could have ever told start off slow. The story is beginning to unfold. You’re unsure. It’s a big commitment lugging this tome around. Maybe this book won’t be that great but you’ll feel guilty about putting it down. Maybe it’ll be so awful you’ll keep hate-reading or just set it down immediately and never pick it up again. Or maybe you’ll come back to it some night, drunk or lonely — needing something to fill the time, but it won’t be any better than it was when you first started reading you’re worn out. You’ve read tons of books before. Some were just light weights on a Kindle or Nook, no big deal really. Others were Infinite Jest-style burdens, heavy on your back or in your purse. Weighing you down all the time. Maybe you’ve taken some time off from reading because the last few books you read just weren’t worth it. Do they even write new, great works of literature anymore? Maybe that time you fell in love with a book before will just never happen for you again. Maybe it’s a once in a lifetime feeling and you’re never gonna find it something exciting could happen. Maybe this will become your new favorite book. That’s always a possibility right? That’s the beauty of risk. The reward could actually be worth it. You invest your time and your brain power in the words and what you get back is empathy and a new understanding and pure wonder. How could someone possibly know you like this? Some stranger, some author, some character. It’s like they’re seeing inside your soul. This book existed inside some book store, on a shelf, maybe handled by other people and really it was just waiting for you pick it up and crack the spine. It was waiting to speak to you. To say, “You are not alone.”You just want more of the story. You want to keep reading, maybe everything this author’s ever written. You wish it would never end. The closer it gets to the smaller side of the pages, the slower you read, wanting to savor it all. This book is now one of your favorites forever. You will always wish you could go back to never having read it and pick it up fresh again, but also you know you’re better for having this close, inside you, covering your heart and you get in deep enough, you know you could never put this book down.
lived in the north, you might think it was nothing. But the following thing was more unreal. A bird, a beautiful parrot, like an angel, flew from the sky onto Charlie’s shoulder and then flew to my shoulder. I didn’t know how to express my feelings, only enjoying it. The parrot didn’t seem to leave. How fantastic, I thought. The snow became smaller and smaller after class. Maybe we lost something, but we
原文 Ultrasonic distance meter Document Type and Number:United States Patent 5442592 Abstract:An ultrasonic distance meter cancels out the effects of temperature and humidity variations by including a measuring unit and a reference unit. In each of the units, a repetitive series of pulses is generated, each having a repetition rate directly related to the respective distance between an electroacoustic transmitter and an electroacoustic receiver. The pulse trains are provided to respective counters, and the ratio of the counter outputs is utilized to determine the distance being measured. Publication Date:08/15/1995 Primary Examiner:Lobo, Ian J. 一、BACKGROUND OF THE INVENTION This invention relates to apparatus for the measurement of distance and, more particularly, to such apparatus which transmits ultrasonic waves between two points. Precision machine tools must be calibrated. In the past, this has been accomplished utilizing mechanical devices such as calipers, micrometers, and the like. However, the use of such devices does not readily lend itself to automation techniques. It is known that the distance between two points can be determined by measuring the propagation time of a wave travelling between those two points. One such type of wave is an ultrasonic, or acoustic, wave. When an ultrasonic wave travels between two points, the distance between the two points can be measured by multiplying the transit time of the wave by the wave velocity in the medium separating the two points. It is therefore an object of the present invention to provide apparatus utilizing ultrasonic waves to accurately measure the distance between two points. When the medium between the two points whose spacing is being measured is air, the sound velocity is dependent upon the temperature and humidity of the air. It is therefore a further object of the,present invention to provide apparatus of the type described which is independent of temperature and humidity variations. 二、SUMMARY OF THE INVENTION The foregoing and additional objects are attained in accordance with the principles of this invention by providing distance measuring apparatus which includes a reference unit and a measuring unit. The reference and measuring units are the same and each includes an electroacoustic transmitter and an electroacoustic receiver. The spacing between the transmitter and the receiver of the reference unit is a fixed reference distance, whereas the spacing between the transmitter and receiver of the measuring unit is the distance to be measured. In each of the units, the transmitter and receiver are coupled by a feedback loop which causes the transmitter to generate an acoustic pulse which is received by the receiver and converted into an electrical pulse which is then fed back to the transmitter, so that a repetitive series of pulses results. The repetition rate of the pulses is inversely related to the distance between the transmitter and the receiver. In each of the units, the pulses are provided to a counter. Since the reference distance is known, the ratio of the counter outputs is utilized to determine the desired distance to be measured. Since both counts are identically influenced by temperature and humidity variations, by taking the ratio of the counts, the resultant measurement becomes insensitive to such variations. 三、BRIEF DESCRIPTION OF THE DRAWINGS The foregoing will be more readily apparent upon reading the following description in conjunction with the drawing in which the single FIGURE schematically depicts apparatus constructed in accordance with the principles of this invention. 四、DETAILED DESCRIPTION Referring now to the drawing, there is shown a measuring unit 10 and a reference unit 12, both coupled to a utilization means 14. The measuring unit 10 includes an electroacoustic transmitter 16 and an electroacoustic receiver 18. The transmitter 16 includes piezoelectric material 20 sandwiched between a pair of electrodes 22 and 24. Likewise, the receiver 18 includes piezoelectric material 26 sandwiched between a pair of electrodes 28 and 30. As is known, by applying an electric field across the electrodes 22 and 24, stress is induced in the piezoelectric material 20. If the field varies, such as by the application of an electrical pulse, an acoustic wave 32 is generated. As is further known, when an acoustic wave impinges upon the receiver 18, this induces stress in the piezoelectric material 26 which causes an electrical signal to be generated across the electrodes 28 and 30. Although piezoelectric transducers have been illustrated, other electroacoustic devices may be utilized, such as, for example, electrostatic, electret or electromagnetic types. As shown, the electrodes 28 and 30 of the receiver 18 are coupled to the input of an amplifier 34, whose output is coupled to the input of a detector 36. The detector 36 is arranged to provide a signal to the pulse former 38 when the output from the amplifier 34 exceeds a predetermined level. The pulse former 38 then generates a trigger pulse which is provided to the pulse generator 40. In order to enhance the sensitivity of the system, the transducers 16 and 18 are resonantly excited. There is accordingly provided a continuous wave oscillator 42 which provides a continuous oscillating signal at a fixed frequency, preferably the resonant frequency of the transducers 16 and 18. This oscillating signal is provided to the modulator 44. To effectively excite the transmitter 16, it is preferable to provide several cycles of the resonant frequency signal, rather than a single pulse or single cycle. Accordingly, the pulse generator 40 is arranged, in response to the application thereto of a trigger pulse, to provide a control pulse to the modulator 44 having a time duration equal the time duration of a predetermined number of cycles of the oscillating signal from the oscillator 42. This control pulse causes the modulator 44 to pass a "burst" of cycles to excite the transmitter 16. When electric power is applied to the described circuitry, there is sufficient noise at the input to the amplifier 34 that its output triggers the pulse generator 40 to cause a burst of oscillating cycles to be provided across the electrodes 22 and 24 of the transmitter 16. The transmitter 16 accordingly generates an acoustic wave 32 which impinges upon the receiver 18. The receiver 18 then generates an electrical pulse which is applied to the input of the amplifier 34, which again causes triggering of the pulse generator 40. This cycle repeats itself so that a repetitive series of trigger pulses results at the output of the pulse former 38. This pulse train is applied to the counter 46, as well as to the pulse generator 40. The transmitter 16 and the receiver 18 are spaced apart by the distance "D" which it is desired to measure. The propagation time "t" for an acoustic wave 32 travelling between the transmitter 16 and the receiver 18 is given by: t=D/V s where V s is the velocity of sound in the air between the transmitter 16 and the receiver 18. The counter 46 measures the repetition rate of the trigger pulses, which is equal to 1/t. Therefore, the repetition rate is equal to V s /D. The velocity of sound in air is a function of the temperature and humidity of the air, as follows: ##EQU1## where T is the temperature, p is the partial pressure of the water vapor, H is the barometric pressure, Γ w and Γ a are the ratio of constant pressure specific heat to constant volume specific heat for water vapor and dry air, respectively. Thus, although the repetition rate of the trigger pulses is measured very accurately by the counter 46, the sound velocity is influenced by temperature and humidity so that the measured distance D cannot be determined accurately. In accordance with the principles of this invention, a reference unit 12 is provided. The reference unit 12 is of the same construction as the measuring unit 10 and therefore includes an electroacoustic transmitter 50 which includes piezoelectric material 52 sandwiched between a pair of electrodes 54 and 56, and an electroacoustic receiver 58 which includes piezoelectric material 60 sandwiched between a pair of electrodes 62 and 64. Again, transducers other than the piezoelectric type can be utilized. The transmitter 50 and the receiver 58 are spaced apart a known and fixed reference distance "D R ". The electrodes 62 and 64 are coupled to the input of the amplifier 66, whose output is coupled to the input of the detector 68. The output of the detector 68 is coupled to the pulse former 70 which generates trigger pulses. The trigger pulses are applied to the pulse generator 72 which controls the modulator 74 to pass bursts from the continuous wave oscillator 76 to the transmitter 50. The trigger pulses from the pulse former 70 are also applied to the counter 78. Preferably, all of the transducers 16, 18, 50 and 58 have the same resonant frequency. Therefore, the oscillators 42 and 76 both operate at that frequency and the pulse generators 40 and 72 provide equal width output pulses. In usage, the measuring unit 10 and the reference unit 12 are in close proximity so that the sound velocity in both of the units is the same. Although the repetition rates of the pulses in the measuring unit 10 and the reference unit 12 are each temperature and humidity dependent, it can be shown that the distance D to be measured is related to the reference distance D R as follows: i D=D R (1/t R )/(1/t) where t R is the propagation time over the distance D R in the reference unit 12. This relationship is independent of both temperature and humidity. Thus, the outputs of the counters 46 and 78 are provided as inputs to the microprocessor 90 in the utilization means 14. The microprocessor 90 is appropriately programmed to provide an output which is proportional to the ratio of the outputs of the counters 46 and 78, which in turn are proportional to the repetition rates of the respective trigger pulse trains of the measuring unit 10 and the reference unit 12. As described, this ratio is independent of temperature and humidity and, since the reference distance D R is known, provides an accurate representation of the distance D. The utilization means 14 further includes a display 92 which is coupled to and controlled by the microprocessor 90 so that an operator can readily determine the distance D. Experiments have shown that when the distance between the transmitting and receiving transducers is too small, reflections of the acoustic wave at the transducer surfaces has a not insignificant effect which degrades the measurement accuracy. Accordingly, it is preferred that each transducer pair be separated by at least a certain minimum distance, preferably about four inches. Accordingly, there has been disclosed improved apparatus for the measurement of distance utilizing ultrasonic waves. While an illustrative embodiment of the present invention has been disclosed herein, it is understood that various modifications and adaptations to the disclosed embodiment will be apparent to those of ordinary skill in the art and it is intended that this invention be limited only by the scope of the appended claims. 译文 超声波测距仪 文件类型和数目：美国专利5442592 摘要：提出了一种超声波测距仪来抵消的影响温度和湿度的变化，包括测量单元和参考资料。在每一个单位，重复的一系列脉冲的产生，每有一个重复率，直接关系到各自之间的距离，发射机和接收机。脉冲提供给各自的主机，和比例的反产出是利用确定的距离被衡量的。 出版日期： 1995年8月15日 主审查员：罗保.伊恩j. 一、背景发明 本发明涉及到仪器的测量距离，更特别是，这种仪器传送超声波两点之间。 精密机床必须校准。在过去，这已经完成利用机械设备，如卡钳，微米等。不过，使用这种装置并不容易本身自动化技术。据了解，该两点之间距离才能确定通过测量传播时间的浪潮往返那些两点。这样一个类型的波是一种超声波，或声，海浪。当超声波旅行两点之间，距离两个点之间可以衡量乘以过境的时间波由波速，在中期分开两点。因此，这是一个对象本发明提供仪器利用超声波准确测量两点之间距离。 当中等两个点之间的间距是被衡量的是空气，声速是取决于温度和空气相对湿度。因此，它是进一步对象的，现在的发明，提供仪器的类型所描述的是独立于温度和湿度的变化。 二、综述发明 前述的和额外的对象是达到了根据这些原则的这项发明提供距离测量仪器，其中包括一个参考的单位和测量单位。参考和测量单位是相同的，每个包括一电发射机和接收机一电。间隔发射器和接收器的参考股是一个固定的参考距离，而间距之间的发射机和接收机的测量单位是距离来衡量。在每一个单位，发射机和接收机是再加上由一个反馈环路导致发射机产生的声脉冲是由接收机和转换成一个电脉冲这是然后反馈到发射机，使重复一系列脉冲的结果。重复率脉冲是成反比关系之间的距离发射器和接收器。在每一个单位，脉冲提供一个反。由于参考的距离是众所周知，比例反产出是利用，以确定所期望的距离来衡量。由于这两方面都是相同的影响，温度和湿度的变化，采取的比例罪状，由此产生的测量变得麻木等变化。 三、简要说明图纸 前述将更加明显后，读下列的说明，在与该绘图并在其中单一数字schematically描绘仪器兴建根据这些原则的这项发明。 四、详细说明 谈到现在的绘图，有结果表明，测量单位和10个参考单位12个，均加上一个利用的手段14 。测量单位包括1 10电发射机16日和1电接收机18 。变送器16包括压电材料20夹心阶层之间的对电极的22日和24日。同样，接收机18个，包括压电材料26夹心阶层之间的对电极的28日和30日。作为众所周知，采用电场整个电极22日和24日，强调的是，诱导，在压电材料20 。如果该字段各有不同，如所申请的一个电脉冲，声波是32所产生的。为进一步众所周知，当声波影响到接收器18 ，这诱导应力，在压电材料26 ，导致一种电信号，以产生全国电极28日和30日。虽然压电传感器已说明，其他电声装置，可利用，例如，静电，驻极体或电磁类型。 如表所示，电极28日和30日的接收18岁以下的耦合的投入一34放大器，其输出耦合输入一个探测器36 。探测器36是安排提供一个信号，脉冲前38时，输出放大器34已经超过预定的水平。脉冲前38 ，然后产生一个触发脉冲，这是提供给脉冲发生器40 。在为了提高灵敏度，该系统，传感器16和18岁以下的共振兴奋。有相应的提供了一个连续波振荡器42提供了一个连续振荡信号在一个固定的频率，最好是共振频率的传感器16和18 。这个振荡信号是提供给调制器44 。要有效地激发发射机16 ，可取的做法是提供几个周期的共振频率信号，而不是一个单脉冲或单周期。因此，脉冲发生器40是安排，在回应的应用存在的一个触发脉冲，提供一个控制脉冲调制器44有一个时间的平等的时间，时间预定人数的周期振荡信号从振荡器42 。这个控制脉冲调制器的原因， 44个通过了“水管爆裂”的周期，以激发发射机16 。 当电力是适用于所描述的电路，有足够的噪音在输入到放大器34 ，其输出触发脉冲发生器40至造成了一片叫好声，振荡周期，以提供整个电极22日和24日的发射器16 。变送器16因此产生声波32条，其中影响到接收器18 。接收器18 ，然后产生一个电脉冲，这是适用于输入放大器的34 ，这再次触发原因的脉冲发生器40 。这个周期重演，使重复一系列的触发脉冲结果的输出脉冲前38 。这脉冲列车是应用到46个柜位，以及向脉冲发生器40 。 变送器16日和接收18岁以下的间隔，除了由距离的“ D ” ，它是理想的衡量。传播时间的“ T ”为一声波32往来变送器16日和接收18所给予的： = D的吨/视频s 凡v s是声速在空气中之间的发射机16日和接收18 。柜台46措施重复率触发脉冲，这是平等的1 /汤匙因此，重复率是平等的一至中五的S /四该声速空气中是一个功能的温度和湿度的空气，内容如下： ＃ ＃ ＃ ＃ equ1其中T是温度， P是局部的压力，水汽， H是该气压， γ瓦特和γ一顷的比例不断的压力，具体的热不断货量具体的热水汽和干燥的空气，分别。因此，虽然重复率触发脉冲测量非常准确地反46 ，声速的影响，温度和湿度，使测量的距离d无法确定准确。 根据这些原则的这项发明，参考单位提供的是12 。参考单位12是相同的建设为测量单位的10个，因此，包括一电发射机50个，其中包括压电材料52夹心之间的一对电极的54和56 ，和一电接收机58 ，其中包括压电材料60夹心阶层之间的一对电极60,61,62和64 。再次，传感器以外的其他类型压电可以利用。变送器50和接收五十八顷间隔，除了已知的和固定的参考距离“博士” 。电极60,61,62和64耦合到输入的放大器66 ，其输出是耦合的投入探测器68 。输出探测器68是耦合的脉搏，前70产生触发脉冲。触发脉冲应用到脉冲发生器的72个控制调制器74通过扫射从连续波振荡器76至变送器50 。触发脉冲从脉冲前70也适用于反78 。 最好是，所有的传感器16 ， 18 ， 50和58具有相同的共振频率。因此，振荡器42和76都在运作，频率和脉冲发电机40和第72条提供平等的输出脉冲宽度。 在用法上，测量装置10和参考资料股一十二顷在接近，使该声速在这两个单位是相同的。虽然留级率的脉冲在测量单位， 10和参考资料股十二顷每个温度和湿度的依赖性，能证明的距离D来衡量。 其中T R是传播时间超过距离博士在参考股12 。这种关系是独立于双方的温度和湿度。 因此，产出的柜台46和78所提供的投入微处理器的90个利用的手段14 。微处理器90是适当的程序提供了一个输出是成正比的比例，产出的柜台46和78 ，这反过来又是成正比的重复率分别触发脉冲列车的测量单位， 10和参考资料股12 。作为描述，这个比例是独立的温度和湿度，由于参考的距离，博士，是众所周知的，提供了一个准确的代表性距离四，利用手段， 14日还包括一个显示92这是耦合和控制的微处理器，使90一个经营者可以随时确定的距离四 实验表明，当之间的距离发射和接收传感器是太小了，思考的声波在传感器的表面有一个不小的作用，降低了测量精度。因此，最好是每换一双分开，至少由某一个最小距离，最好是约四英寸。 因此，已披露的改善仪器的测量距离，利用超声波。而一个说明性的体现，本发明已披露者外，据了解，各种修改和适应所披露的体现，将是显而易见的那些普通的技巧与艺术，这是打算把这个发明只限于由范围所附的索赔。
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This article described the three directions (before, left, right) ultrasonic ranging system is to understand the front of the robot, left and right environment to provide a movement away from the information. (Similar to GPS Positioning System)A principle of ultrasonic distance measurement1, the principle of piezoelectric ultrasonic generatorPiezoelectric ultrasonic generator is the use of piezoelectric crystal resonators to work. Ultrasonic generator, the internal structure as shown in Figure 1, it has two piezoelectric chip and a resonance plate. When it's two plus pulse signal, the frequency equal to the intrinsic piezoelectric oscillation frequency chip, the chip will happen piezoelectric resonance, and promote the development of plate vibration resonance, ultrasound is generated. Conversely, if the two are not inter-electrode voltage, when the board received ultrasonic resonance, it will be for vibration suppression of piezoelectric chip, the mechanical energy is converted to electrical signals, then it becomes the ultrasonic , the principle of ultrasonic distance measurementUltrasonic transmitter in a direction to launch ultrasound, in the moment to launch the beginning of time at the same time, the spread of ultrasound in the air, obstacles on his way to return immediately, the ultrasonic reflected wave received by the receiver immediately stop the clock. Ultrasound in the air as the propagation velocity of 340m / s, according to the timer records the time t, we can calculate the distance between the launch distance barrier (s), that is: s = 340t / 2Ultrasonic Ranging System for the Second Circuit DesignSystem is characterized by single-chip microcomputer to control the use of ultrasonic transmitter and ultrasonic receiver since the launch from time to time, single-chip selection of 8751, economic-to-use, and the chip has 4K of ROM, to facilitate programming. Circuit schematic diagram shown in Figure 2. Draw only the front range of the circuit wiring diagram, left and right in front of Ranging Ranging circuits and the same circuit, it is kHz ultrasonic pulse generated with the launchRanging system using the ultrasonic sensor of piezoelectric ceramic sensors UCM40, its operating voltage of the pulse signal is 40kHz, which by the single-chip implementation of the following procedures to : mov 14h, # 12h; ultrasonic firing continued 200mshere: cpl ; output 40kHz square wavenop;nop;nop;djnz 14h, here;retRanging in front of single-chip termination circuit input port, single chip implementation of the above procedure, the port in a 40kHz pulse output signal, after amplification transistor T, the drive to launch the first ultrasonic UCM40T, issued 40kHz ultrasonic pulse, and the continued launch of 200ms. Ranging the right and the left side of the circuit, respectively, then input port and , the working principle and circuit in front of the same , reception and processing of ultrasonicUsed to receive the first launch of the first pair UCM40R, the ultrasonic pulse modulation signal into an alternating voltage, the op-amp amplification IC1A and after polarization IC1B to IC2. IC2 is locked loop with audio decoder chip LM567, internal voltage-controlled oscillator center frequency of f0 = 1/, capacitor C4 determine their target bandwidth. R8-conditioning in the launch of the carrier frequency on the LM567 input signal is greater than 25mV, the output from the high jump 8 feet into a low-level, as interrupt request signals to the single-chip in front of single-chip termination circuit output port INT0 interrupt the highest priority, right or left location of the output circuit with output gate IC3A access INT1 port single-chip, while single-chip and P1. 4 received input IC3A, interrupted by the process to identify the source of inquiry to deal with, interrupt priority level for the first left right after. Part of the source code is as follows:receive1: push pswpush accclr ex1; related external interrupt 1jnb , right; pin to 0, ranging from right to interrupt service routine circuitjnb , left; pin to 0, to the left ranging circuit interrupt service routinereturn: SETB EX1; open external interrupt 1pop? accpop? pswretiright: ...?; right location entrance circuit interrupt service routine? Ajmp? Returnleft: ...; left Ranging entrance circuit interrupt service routine? Ajmp? Return4, the calculation of ultrasonic propagation timeWhen you start firing at the same time start the single-chip circuitry within the timer T0, the use of timer counting function records the time and the launch of ultrasonic reflected wave received time. When you receive the ultrasonic reflected wave, the receiver circuit outputs a negative jump in the end of INT0 or INT1 interrupt request generates a signal, single-chip microcomputer in response to external interrupt request, the implementation of the external interrupt service subroutine, read the time difference, calculating the distance . Some of its source code is as follows:RECEIVE0: PUSH PSWPUSH ACCCLR EX0; related external interrupt 0? MOV R7, TH0; read the time valueMOV R6, TL0?CLR CMOV A, R6SUBB A, # 0BBH; calculate the time differenceMOV 31H, A; storage resultsMOV A, R7SUBB A, # 3CHMOV 30H, A?SETB EX0; open external interrupt 0POP ACC?POP PSWRETIFourth, the ultrasonic ranging system software designSoftware is divided into two parts, the main program and interrupt service routine, shown in Figure 3 (a) (b) (c) below. Completion of the work of the main program is initialized, each sequence of ultrasonic transmitting and receiving service routines from time to time to complete three of the rotation direction of ultrasonic launch, the main external interrupt service subroutine to read the value of completion time, distance calculation, the results of the output and so . CONCLUSIONSRequired measuring range of 30cm ~ 200cm objects inside the plane to do a number of measurements found that the maximum error is , and good reproducibility. Single-chip design can be seen on the ultrasonic ranging system has a hardware structure is simple, reliable, small features such as measurement error. Therefore, it can be used not only for mobile robot can be used in other detection : As for why the receiver do not have the transistor amplifier circuit, because the magnification well, CX20106 integrated amplifier, but also with automatic gain control level, magnification to 76dB, the center frequency is 38k to 40k, is exactly resonant ultrasonic sensors frequency=====本文所介绍的三方向（前、左、右）超声波测距系统，就是为机器人了解其前方、左侧和右侧的环境而提供一个运动距离信息。（类似GPS定位系统）一 超声波测距原理1、压电式超声波发生器原理压电式超声波发生器实际上是利用压电晶体的谐振来工作的。超声波发生器内部结构如图1所示，它有两个压电晶片和一个共振板。当它的两极外加脉冲信号，其频率等于压电晶片的固有振荡频率时，压电晶片将会发生共振，并带动共振板振动，便产生超声波。反之，如果两电极间未外加电压，当共振板接收到超声波 时，将压迫压电晶片作振动，将机械能转换为电信号，这时它就成为超声波接收器了。2、超声波测距原理超声波发射器向某一方向发射超声波，在发射时刻的同时开始计时，超声波在空气中传播，途中碰到障碍物就立即返回来，超声波接收器收到反射波就立即停止计时。超声波在空气中的传播速度为340m/s，根据计时器记录的时间t，就可以计算出发射点距障碍物的距离(s)，即：s=340t/2二 超声波测距系统的电路设计系统的特点是利用单片机控制超声波的发射和对超声波自发射至接收往返时间的计时，单片机选用8751，经济易用，且片内有4K的ROM，便于编程。电路原理图如图2所示。其中只画出前方测距电路的接线图，左侧和右侧测距电路与前方测距电路相同，故省略之。1、40kHz 脉冲的产生与超声波发射测距系统中的超声波传感器采用UCM40的压电陶瓷传感器，它的工作电压是40kHz的脉冲信号，这由单片机执行下面程序来产生。puzel： mov 14h, #12h；超声波发射持续200mshere： cpl ； 输出40kHz方波nop ；nop ；nop ；djnz 14h，here；ret前方测距电路的输入端接单片机端口，单片机执行上面的程序后，在 端口输出一个40kHz的脉冲信号，经过三极管T放大，驱动超声波发射头UCM40T，发出40kHz的脉冲超声波，且持续发射200ms。右侧和左侧测 距电路的输入端分别接和端口，工作原理与前方测距电路相同。2、超声波的接收与处理接收头采用与发射头配对的UCM40R，将超声波调制脉冲变为交变电压信号，经运算放大器IC1A和IC1B两极放大后加至IC2。IC2是带有锁 定环的音频译码集成块LM567，内部的压控振荡器的中心频率f0=1/，电容C4决定其锁定带宽。调节R8在发射的载频上，则LM567 输入信号大于25mV，输出端8脚由高电平跃变为低电平，作为中断请求信号，送至单片机处理.前方测距电路的输出端接单片机INT0端口，中断优先级最高，左、右测距电路的输出通过与门IC3A的输出接单片机INT1端口，同时单片机和接到IC3A的输入端，中断源的识别由程序查询来处理，中断优先级为先右后左。部分源程序如下：receive1：push pswpush accclr ex1 ； 关外部中断1jnb , right ； 引脚为0,转至右测距电路中断服务程序jnb , left ； 引脚为0,转至左测距电路中断服务程序return： SETB EX1； 开外部中断1pop? accpop? pswretiright： ...? ； 右测距电路中断服务程序入口? ajmp? returnleft： ... ； 左测距电路中断服务程序入口? ajmp? return4、计算超声波传播时间在启动发射电路的同时启动单片机内部的定时器T0，利用定时器的计数功能记录超声波发射的时间和收到反射波的时间。当收到超声波反射波时，接收电路 输出端产生一个负跳变，在INT0或INT1端产生一个中断请求信号，单片机响应外部中断请求，执行外部中断服务子程序，读取时间差，计算距离。其部分源程序如下：RECEIVE0： PUSH PSWPUSH ACCCLR EX0 ； 关外部中断0? MOV R7, TH0 ； 读取时间值MOV R6, TL0?CLR CMOV A, R6SUBB A, #0BBH； 计算时间差MOV 31H, A ； 存储结果MOV A, R7SUBB A, #3CHMOV 30H, A?SETB EX0 ； 开外部中断0POP ACC?POP PSWRETI四、超声波测距系统的软件设计软件分为两部分，主程序和中断服务程序，如图3（a）（b）(c) 所示。主程序完成初始化工作、各路超声波发射和接收顺序的控制。定时中断服务子程序完成三方向超声波的轮流发射，外部中断服务子程序主要完成时间值的读取、距离计算、结果的输出等工作。五、结论对所要求测量范围30cm~200cm内的平面物体做了多次测量发现，其最大误差为，且重复性好。可见基于单片机设计的超声波测距系统具有硬件结构简单、工作可靠、测量误差小等特点。因此，它不仅可用于移动机器人，还可用在其它检测系统中。思考：至于为什么接收不用晶体管做放大电路呢，因为放大倍数搞不好，CX20106集成放大电路，还带自动电平增益控制，放大倍数为76dB，中心频率是38k到40k，刚好是超声波传感器的谐振频率 。【希望可以帮助你】
Introduction vibrations of frequencies greater than the upper limit of the audible range for humans—that is, greater than about 20 kilohertz. The term sonic is applied to ultrasound waves of very high amplitudes. Hypersound, sometimes called praetersound or microsound, is sound waves of frequencies greater than 1013 hertz. At such high frequencies it is very difficult for a sound wave to propagate efficiently; indeed, above a frequency of about × 1013 hertz, it is impossible for longitudinal waves to propagate at all, even in a liquid or a solid, because the molecules of the material in which the waves are traveling cannot pass the vibration along rapidly enough. TableMany animals have the ability to hear sounds in the human ultrasonic frequency range. Some ranges of hearing for mammals and insects are compared with those of humans in the Table. A presumed sensitivity of roaches and rodents to frequencies in the 40 kilohertz region has led to the manufacture of “pest controllers” that emit loud sounds in that frequency range to drive the pests away, but they do not appear to work as advertised. Transducers An ultrasonic transducer is a device used to convert some other type of energy into an ultrasonic vibration. There are several basic types, classified by the energy source and by the medium into which the waves are being generated. Mechanical devices include gas-driven, or pneumatic, transducers such as whistles as well as liquid-driven transducers such as hydrodynamic oscillators and vibrating blades. These devices, limited to low ultrasonic frequencies, have a number of industrial applications, including drying, ultrasonic cleaning, and injection of fuel oil into burners. Electromechanical transducers are far more versatile and include piezoelectric and magnetostrictive devices. A magnetostrictive transducer makes use of a type of magnetic material in which an applied oscillating magnetic field squeezes the atoms of the material together, creating a periodic change in the length of the material and thus producing a high-frequency mechanical vibration. Magnetostrictive transducers are used primarily in the lower frequency ranges and are common in ultrasonic cleaners and ultrasonic machining applications. By far the most popular and versatile type of ultrasonic transducer is the piezoelectric crystal, which converts an oscillating electric field applied to the crystal into a mechanical vibration. Piezoelectric crystals include quartz, Rochelle salt, and certain types of ceramic. Piezoelectric transducers are readily employed over the entire frequency range and at all output levels. Particular shapes can be chosen for particular applications. For example, a disc shape provides a plane ultrasonic wave, while curving the radiating surface in a slightly concave or bowl shape creates an ultrasonic wave that will focus at a specific point. Piezoelectric and magnetostrictive transducers also are employed as ultrasonic receivers, picking up an ultrasonic vibration and converting it into an electrical oscillation. Applications in research One of the important areas of scientific study in which ultrasonics has had an enormous impact is cavitation. When water is boiled, bubbles form at the bottom of the container, rise in the water, and then collapse, leading to the sound of the boiling water. The boiling process and the resulting sounds have intrigued people since they were first observed, and they were the object of considerable research and calculation by the British physicists Osborne Reynolds and Lord Rayleigh, who applied the term cavitation to the process of formation of bubbles. Because an ultrasonic wave can be used carefully to control cavitation, ultrasound has been a useful tool in the investigation of the process. The study of cavitation has also provided important information on intermolecular forces. Research is being carried out on aspects of the cavitation process and its applications. A contemporary subject of research involves emission of light as the cavity produced by a high-intensity ultrasonic wave collapses. This effect, called sonoluminescence, is believed to create instantaneous temperatures hotter than the surface of the Sun. The speed of propagation of an ultrasonic wave is strongly dependent on the viscosity of the medium. This property can be a useful tool in investigating the viscosity of materials. Because the various parts of a living cell are distinguished by differing viscosities, acoustical microscopy can make use of this property of cells to “see” into living cells, as will be discussed below in Medical applications. Ranging and navigating Sonar (sound navigation and ranging) has extensive marine applications. By sending out pulses of sound or ultrasound and measuring the time required for the pulses to reflect off a distant object and return to the source, the location of that object can be ascertained and its motion tracked. This technique is used extensively to locate and track submarines at sea and to locate explosive mines below the surface of the water. Two boats at known locations can also use triangulation to locate and track a third boat or submarine. The distance over which these techniques can be used is limited by temperature gradients in the water, which bend the beam away from the surface and create shadow regions. One of the advantages of ultrasonic waves over sound waves in underwater applications is that, because of their higher frequencies (or shorter wavelengths), the former will travel greater distances with less diffraction. Ranging has also been used to map the bottom of the ocean, providing depth charts that are commonly used in navigation, particularly near coasts and in shallow waterways. Even small boats are now equipped with sonic ranging devices that determine and display the depth of the water so that the navigator can keep the boat from beaching on submerged sandbars or other shallow points. Modern fishing boats use ultrasonic ranging devices to locate schools of fish, substantially increasing their efficiency. Even in the absence of visible light, bats can guide their flight and even locate flying insects (which they consume in flight) through the use of sonic ranging. Ultrasonic echolocation has also been used in traffic control applications and in counting and sorting items on an assembly line. Ultrasonic ranging provides the basis of the eye and vision systems for robots, and it has a number of important medical applications (see below). The Doppler effect If an ultrasonic wave is reflected off a moving obstacle, the frequency of the resulting wave will be changed, or Doppler-shifted. More specifically, if the obstacle is moving toward the source, the frequency of the reflected wave will be increased; and if the obstacle is moving away from the source, the frequency of the reflected wave will be decreased. The amount of the frequency shift can be used to determine the velocity of the moving obstacle. Just as the Doppler shift for radar, an electromagnetic wave, can be used to determine the speed of a moving car, so can the speed of a moving submarine be determined by the Doppler shift of a sonar beam. An important industrial application is the ultrasonic flow meter, in which reflecting ultrasound off a flowing liquid leads to a Doppler shift that is calibrated to provide the flow rate of the liquid. This technique also has been applied to blood flow in arteries. Many burglar alarms, both for home use and for use in commercial buildings, employ the ultrasonic Doppler shift principle. Such alarms cannot be used where pets or moving curtains might activate them. Materials testing Nondestructive testing involves the use of ultrasonic echolocation to gather information on the integrity of mechanical structures. Since changes in the material present an impedance mismatch from which an ultrasonic wave is reflected, ultrasonic testing can be used to identify faults, holes, cracks, or corrosion in materials, to inspect welds, to determine the quality of poured concrete, and to monitor metal fatigue. Owing to the mechanism by which sound waves propagate in metals, ultrasound can be used to probe more deeply than any other form of radiation. Ultrasonic procedures are used to perform in-service inspection of structures in nuclear reactors. Structural flaws in materials can also be studied by subjecting the materials to stress and looking for acoustic emissions as the materials are stressed. Acoustic emission, the general name for this type of nondestructive study, has developed as a distinct field of acoustics. High-intensity applications High-intensity ultrasound has achieved a variety of important applications. Perhaps the most ubiquitous is ultrasonic cleaning, in which ultrasonic vibrations are set up in small liquid tanks in which objects are placed for cleaning. Cavitation of the liquid by the ultrasound, as well as the vibration, create turbulence in the liquid and result in the cleaning action. Ultrasonic cleaning is very popular for jewelry and has also been used with such items as dentures, surgical instruments, and small machinery. Degreasing is often enhanced by ultrasonic cleaning. Large-scale ultrasonic cleaners have also been developed for use in assembly lines. Ultrasonic machining employs the high-intensity vibrations of a transducer to move a machine tool. If necessary, a slurry containing carborundum grit may be used; diamond tools can also be used. A variation of this technique is ultrasonic drilling, which makes use of pneumatic vibrations at ultrasonic frequencies in place of the standard rotary drill bit. Holes of virtually any shape can be drilled in hard or brittle materials such as glass, germanium, or ceramic. Ultrasonic soldering has become important, especially for soldering unusual or difficult materials and for very clean applications. The ultrasonic vibrations perform the function of cleaning the surface, even removing the oxide layer on aluminum so that the material can be soldered. Because the surfaces can be made extremely clean and free from the normal thin oxide layer, soldering flux becomes unnecessary. Chemical and electrical uses The chemical effects of ultrasound arise from an electrical discharge that accompanies the cavitation process. This forms a basis for ultrasound's acting as a catalyst in certain chemical reactions, including oxidation, reduction, hydrolysis, polymerization and depolymerization, and molecular rearrangement. With ultrasound, some chemical processes can be carried out more rapidly, at lower temperatures, or more efficiently. The ultrasonic delay line is a thin layer of piezoelectric material used to produce a short, precise delay in an electrical signal. The electrical signal creates a mechanical vibration in the piezoelectric crystal that passes through the crystal and is converted back to an electrical signal. A very precise time delay can be achieved by constructing a crystal with the proper thickness. These devices are employed in fast electronic timing circuits. Medical applications Although ultrasound competes with other forms of medical imaging, such as X-ray techniques and magnetic resonance imaging, it has certain desirable features—for example, Doppler motion study—that the other techniques cannot provide. In addition, among the various modern techniques for the imaging of internal organs, ultrasonic devices are by far the least expensive. Ultrasound is also used for treating joint pains and for treating certain types of tumours for which it is desirable to produce localized heating. A very effective use of ultrasound deriving from its nature as a mechanical vibration is the elimination of kidney and bladder stones. Diagnosis Much medical diagnostic imaging is carried out with X rays. Because of the high photon energies of the X ray, this type of radiation is highly ionizing—that is, X rays are readily capable of destroying molecular bonds in the body tissue through which they pass. This destruction can lead to changes in the function of the tissue involved or, in extreme cases, its annihilation. One of the important advantages of ultrasound is that it is a mechanical vibration and is therefore a nonionizing form of energy. Thus, it is usable in many sensitive circumstances where X rays might be damaging. Also, the resolution of X rays is limited owing to their great penetrating ability and the slight differences between soft tissues. Ultrasound, on the other hand, gives good contrast between various types of soft tissue. Ultrasonic scanning in medical diagnosis uses the same principle as sonar. Pulses of high-frequency ultrasound, generally above one megahertz, are created by a piezoelectric transducer and directed into the body. As the ultrasound traverses various internal organs, it encounters changes in acoustic impedance, which cause reflections. The amount and time delay of the various reflections can be analyzed to obtain information regarding the internal organs. In the B-scan mode, a linear array of transducers is used to scan a plane in the body, and the resultant data is displayed on a television screen as a two-dimensional plot. The A-scan technique uses a single transducer to scan along a line in the body, and the echoes are plotted as a function of time. This technique is used for measuring the distances or sizes of internal organs. The M-scan mode is used to record the motion of internal organs, as in the study of heart dysfunction. Greater resolution is obtained in ultrasonic imaging by using higher frequencies—., shorter wavelengths. A limitation of this property of waves is that higher frequencies tend to be much more strongly absorbed. Because it is nonionizing, ultrasound has become one of the staples of obstetric diagnosis. During the process of drawing amniotic fluid in testing for birth defects, ultrasonic imaging is used to guide the needle and thus avoid damage to the fetus or surrounding tissue. Ultrasonic imaging of the fetus can be used to determine the date of conception, to identify multiple births, and to diagnose abnormalities in the development of the fetus. Ultrasonic Doppler techniques have become very important in diagnosing problems in blood flow. In one technique, a three-megahertz ultrasonic beam is reflected off typical oncoming arterial blood with a Doppler shift of a few kilohertz—a frequency difference that can be heard directly by a physician. Using this technique, it is possible to monitor the heartbeat of a fetus long before a stethoscope can pick up the sound. Arterial diseases such as arteriosclerosis can also be diagnosed, and the healing of arteries can be monitored following surgery. A combination of B-scan imaging and Doppler imaging, known as duplex scanning, can identify arteries and immediately measure their blood flow; this has been extensively used to diagnose heart valve defects. Using ultrasound with frequencies up to 2,000 megahertz, which has a wavelength of micrometre in soft tissues (as compared with a wavelength of about micrometre for light), ultrasonic microscopes have been developed that rival light microscopes in their resolution. The distinct advantage of ultrasonic microscopes lies in their ability to distinguish various parts of a cell by their viscosity. Also, because they require no artificial contrast mediums, which kill the cells, acoustic microscopy can study actual living cells. Therapy and surgery Because ultrasound is a mechanical vibration and can be well focused at high frequencies, it can be used to create internal heating of localized tissue without harmful effects on nearby tissue. This technique can be employed to relieve pains in joints, particularly in the back and shoulder. Also, research is now being carried out in the treatment of certain types of cancer by local heating, since focusing intense ultrasonic waves can heat the area of a tumour while not significantly affecting surrounding tissue. Trackless surgery—that is, surgery that does not require an incision or track from the skin to the affected area—has been developed for several conditions. Focused ultrasound has been used for the treatment of Parkinson's disease by creating brain lesions in areas that are inaccessible to traditional surgery. A common application of this technique is the destruction of kidney stones with shock waves formed by bursts of focused ultrasound. In some cases, a device called an ultrasonic lithotripter focuses the ultrasound with the help of X-ray guidance, but a more common technique for destruction of kidney stones, known as endoscopic ultrasonic disintegration, uses a small metal rod inserted through the skin to deliver ultrasound in the 22- to 30-kilohertz frequency region. Infrasonics The term infrasonics refers to waves of a frequency below the range of human hearing—., below about 20 hertz. Such waves occur in nature in earthquakes, waterfalls, ocean waves, volcanoes, and a variety of atmospheric phenomena such as wind, thunder, and weather patterns. Calculating the motion of these waves and predicting the weather using these calculations, among other information, is one of the great challenges for modern high-speed computers. TableAircraft, automobiles, or other rapidly moving objects, as well as air handlers and blowers in buildings, also produce substantial amounts of infrasonic radiation. Studies have shown that many people experience adverse reactions to large intensities of infrasonic frequencies, developing headaches, nausea, blurred vision, and dizziness. On the other hand, a number of animals are sensitive to infrasonic frequencies, as indicated in the Table. It is believed by many zoologists that this sensitivity in animals such as elephants may be helpful in providing them with early warning of earthquakes and weather disturbances. It has been suggested that the sensitivity of birds to infrasound aids their navigation and even affects their migration. One of the most important examples of infrasonic waves in nature is in earthquakes. Three principal types of earthquake wave exist: the S-wave, a transverse body wave; the P-wave, a longitudinal body wave; and the L-wave, which propagates along the boundary of stratified mediums. L-waves, which are of great importance in earthquake engineering, propagate in a similar way to water waves, at low velocities that are dependent on frequency. S-waves are transverse body waves and thus can only be propagated within solid bodies such as rocks. P-waves are longitudinal waves similar to sound waves; they propagate at the speed of sound and have large ranges. When P-waves propagating from the epicentre of an earthquake reach the surface of the Earth, they are converted into L-waves, which may then damage surface structures. The great range of P-waves makes them useful in identifying earthquakes from observation points a great distance from the epicentre. In many cases, the most severe shock from an earthquake is preceded by smaller shocks, which provide advance warning of the greater shock to come. Underground nuclear explosions also produce P-waves, allowing them to be monitored from any point in the world if they are of sufficient intensity. The reflection of man-made seismic shocks has helped to identify possible locations of oil and natural-gas sources. Distinctive rock formations in which these minerals are likely to be found can be identified by sonic ranging, primarily at infrasonic frequencies.