基于PLC的自动灌装机的伺服电机的设计

<正>1.引言当前国内灌装主要存在的问题是灌装效率低,灌装机的自动化和集成化程度低,这大大降低了工业生产的效率。针对以上的问题,使用在工业领域内使用广泛的PLC作为主控制器,实现灌装系统的自动进瓶,按照瓶口的大小自动定位,按照瓶子的容积自动灌装,自动出瓶等一系列功能,大大提高了工业灌装效率。[1]     

现场总线的的定义

现场总线以数字信号取代模拟信号，在3C技术即计算机（Computer）、控制（Control）、通信（Communication）的基础上，大量现场检测与控制的信息就地采集、就地处理、就地使用，     

循环码的周期分布的新的计算公式

本文在［１］文的基础上进一步分析了循环码的周期分布的性质，给出了新的计算方法和公式，并且确定了一些熟知的循环码的周期分布。     

简单的就是最好的

他的器材，在大家的眼里也许有些发烧。仔细研究后，你不得不承认这套系统很实用，又不失灵活性，通过自由的组合，在面积并不算大的家中发挥着重要的作用。一套效果不错的家庭影院的搭建过程原来并不是那么复杂与昂贵。对于开吻的发烧历程，说不定你能从他的身上找到些当年的影子。     

自然的就是最好的

事实上,很多物品的灵感来自于自然,专业一些的说法叫仿生。不过这种黎法似乎显得太过严肃和学术,对于那些生活中和身边的物品,称它们是向自然讨教得来的一种“比喻”更形象。     

测试用例的复用技术的研究

软件测试是确保软件质量的可靠手段,是软件开发过程中必不可少的重要环节。随着软件项目中各类干系人对软件质量的要求不断提高,软件测试作为保证软件质量的主要途径之一,其重要性越来越受重视。随着软件复杂性提高,软件测试的复杂性也不断提高,测试成本不断增加,同时软件复用技术也在不断发展,软件测试成本的提高和软件复用技术的发展,促使了软件测试复用技术的不断发展。测试复用技术在软件领域得到了广泛的应用,在某些行业软件中得到了很好的应用,比如证券行业。     

创新的机制 超常的发展

《IT时代周刊》是由著名媒体人曹健先生于2001年创建的,历经11年的发展,在姹紫嫣红的媒体百花园里脱颖而出,成为一枝令人瞩目的奇葩。目前该刊发行量达到25万册,年广告额达到3500万元,一跃成为国内发行量最大的IT杂志,深受广大读者特别是IT行业人士的     

适合的才是最好的!谈交换机的选购

在任何网络中交换机是必不可少的，它的主要工作就是数据链路层和网络层进行数据交换，没有了交换机几乎就谈不到网络。但是我们在选购交换机时有时只看中了速度这一技术指标，尽管他很重要，但是有些时候高速交换机却并非我们所需的。     

我们的奥运 我们的努力

华丽的词藻,精美的图片,都不足以代表 MI 众对2008年北京类运会的期盼与祝福之情。所以,我们用了最普通、最直接的方式寄托对奥运会的愿望,在本期策划中,邀请到 MI 特殊的读者——众多合作伙伴写下了对奥运会的诚挚祝愿,字里行间带着他们对奥运期盼,以及对奥运的承诺——为奥运添光彩,为奥运     

戚广崇的收藏半导体的黄金时代

享受政府特殊津贴专家，上海中医药大学附属岳阳中西医结合医院男科主任医师，国内中医、中西医结合研究与诊治不育症、性功能障碍等男科病的开拓者之一。现任国际中医男科学会副主席、世界中医药学会联合会男科学会副会长、中华中医药学会男科学会副理事长、不育症专业委员会主任委员，《中华男科学杂志》、《生殖与避孕》杂志等杂志编委，历任上海医学领先专业中西医结合不育症特色专科学科主任、上海市中医不育症医疗协作中心主任、中国首届、二届中医不育症学术大会主席、全国首届青年中医性医学研讨会主席、中国首届中医男科学术大会执行主席等。     

Fluoride and apatite formation in vivo and in vitro

In recent years, the biomineralization process has attracted much interest from academics and industries for potential technological application. The rule in biomineralization is to have a variety of interfaces and surfaces which can act as nucleators. The ultimate step in any biomineralization process, i.e. the deposition of mineral, must conform to the driving forces operating on the system. A new paradigm in the assessment of the driving force for biomineralization is that a variety of ions existing in the mineralizing milieu are not a bystander, but are instead an active player that directly regulates the precipitation process and nature of biogenic apatites. Thus, the most putative stoichiometric model of a biomineral is (Ca)(5-x)(Mg)q(Na)u(HPO4)v(CO3)w(PO4)(3-y)(OH,F)(1-z). Fluoride participates in many aspects of calcium phosphate formation in vivo and has enormous effects on its process and on the nature and properties of the final products. In the development of biogenic apatites, fluoride ion in the mineralizing media is supposed to accelerate the hydrolysis of acidic precursor(s) and increase the growth rates by augmenting the driving force for precipitation. Inhibitory activities of ions and molecules are related to their adsorption onto the apatite surfaces. From theoretical and practical points of view, it is of paramount importance to elucidate and predict the effect and outcome of fluoride (accelerator) and inhibitors of biological relevance, because of their use in combination for healthcare in dentistry and medicine, e.g. prevention of dental caries and calculus deposition and in the formulation of antiosteoporosis treatments.     

Security and privacy in RFID and applications in telemedicine

Radio frequency identification systems have many applications in manufacturing, supply chain management, inventory control, and telemedicine. In an RFID system, products and objects are given RFID tags to identify themselves. However, security and privacy issues pose significant challenges on these systems. In this article we first briefly introduce RFID systems. Then two RFID applications in telemedicine are proposed: studying supply and demand of doctors, nurses, and patients in hospitals and healthcare, and developing mobile telemedicine services. The security and privacy issues of RFID, and their solutions are discussed as well.     

Electrical ionization and breakdown in gaseous ethylene derivatives and in isoprene

Townsend primary and secondary ionization coefficients have been measured and sparking voltages deduced for di- and tri-methyl ethylene and for isoprene over a pressure range of 2 to 200 Torr and a parallel plate gap distance up to 1 cm yielding derived sparking voltages in excess of 500 000 V. The Townsend equation for ionization is found to be closely obeyed by the gases and vapours and the Townsend constants have been derived. A detailed analysis of the experimental results shows that progressive methyl substitution around the ethylene double bond influeneces the electrical characteristics less markedly than straight chain substitution, in line with further electrical data taken from other sources on hydrocarbons.     

IT安全化安全IT化--信息安全产业发展问题与思考

信息安全在IT业中的角色演变 在当今信息时代,信息技术日新月异,信息产业已经成为拉动GDP增长的第一支柱产业,并以每年20%—30％的速度迅猛发展。其发展过程也经历了从传统IT向新型IT的转变,其中一个重要的转变因素便是信息安全。 1.传统IT与信息安全的关系。传统IT涵盖了五大类:通信、网络、计算机、软件、电子材料及元器件。这五类IT行业本身的发展一度呈现结构失衡:一方面过度投资到“信息高速公     

《信号与系统》中卷积教学思考以及在AI技术中的应用

《信号与系统》课程是电子信息类专业的专业基础课程,本课程是以数学理论引出信号处理的基本方法,进一步在工程应用中应用。本文针对该课程的理论性强和工程应用背景厚等特点,通过对卷积的思考及拓展,举例阐述卷积的计算过程及含义,通过在教学中引入前沿的科技热点,对传统的教学进行改革。激发学生探究基本概念的本质,引导学生积极思考,进一步提高教学效果。     

网络化智能传感器及其在航空航天领域中的应用

目前,我国航空航天领域中测控系统仍然采用传统的测量模式,与国外先进测试水平有着很大差距,其中的差距之一就是传感器缺少智能化、网络化功能。本文首先介绍了智能传感器的概念、功能,然后概述了智能传感器在网络化方面的进展和研究现状,之后论述了网络化智能传感器在航空航天领域中的研究和应用情况。从其研究和应用角度看,美国在智能传感器网络化方面已经开展了多年研究,并且取得了很大进展,很多研究结果都已经得到应用,我国需要积极开展此项方面的研究工作,以提高我国航空航天领域的测试水平,以便更好适应航空航天事业的发展。     

Radiocommunication and control in mines and tunnels

A new system of electromagnetic propagation by means of a coaxial cable designed for radiocommunication in mines and tunnels is described. Theoretical results and their application to the radiocontrol of a winch are presented.     

多媒体厅室电声设计中的声场分布与测量

研究了大、中学校多媒体教室及报告厅常用的主声源及声场分布,给出了上述教室及报告厅电声环境构建中设计、测量的简单实用方法。对听音者的听音效果及质量追求有较为重要的实际意义。     

Periodic bandgap and effective dielectric materials in electromagnetics: characterization and applications in nanocavities and waveguides

The main objectives of this paper are to characterize and develop insight into the performance of photonic bandgap (PBG) periodic dielectric materials and to integrate the results into some novel applications. A powerful computational engine utilizing the finite-difference time-domain technique with periodic boundary conditions/perfectly matched layers integrated with Prony's method is applied to provide an in-depth look at the physics of PBG/periodic bandgap structures. Next, the results are incorporated into two classes of applications in the areas of nanocavity lasers and guidance of electromagnetic (EM) waves in sharp bends. A two-dimensional PBG structure with finite thickness is presented to strongly localize the EM waves in three directions and design a high-Q nanocavity laser. It is shown that the periodic PBG/total internal reflections remarkably trap the EM waves inside the defect region. The effect of the number of periodic cells and defect's dielectric constant on the Q of structure is investigated. It has been found that a seven-layer PBG with a dielectric impurity defect can be used in the design of a laser with a Q as high as 1050. Additionally, potential applications of the PBG structures for guiding the EM waves in sharp bends, namely, 90/spl deg/ and 60/spl deg/ channels are demonstrated. It is shown that shaping the bend by introducing small holes can noticeably improve the guidance of the waves at the bends and channel the EM waves with great efficiency. A comparative study between PBG and effective dielectric materials in controlling the EM waves is also provided and it is observed that the novel characteristics of the PBG cannot be modeled using the effective material for the frequencies within the bandgap.