热电式温显保健水杯的设计与实现

针对日常安全饮水、防止饮用过冷或过热造成对身体的伤害的目的,设计电路的软件部分采用以C语言编程, 硬件部分以STC89C51 单片机为核心,设计升压电路、储能单元和LCD显示模块。提醒人们安全饮水,达到保健、环保与低碳的目的。     

单核李斯特菌溶血素蛋白的原核表达及纯化

目的原核表达并纯化单核李斯特菌(Listeria monocytogenes,LM)溶血素(Listeriolysin O,LLO)蛋白。方法用1对LM LLO基因特异性引物从LM基因组DNA中扩增LLO基因,并构建重组原核表达质粒pET-30a(+)/rLLO,转化大肠杆菌BL21(DE3),IPTG诱导表达。表达的rLLO蛋白经镍离子金属螯合柱纯化后,进行SDS-PAGE及质谱分析。结果重组表达质粒pET-30a(+)/rLLO经PCR、双酶切及测序,证明构建正确。表达的rLLO融合蛋白相对分子质量约为78 000,主要以包涵体形式表达。质谱分析显示,两个相对分子质量分别为35 000和45 000的小分子也均为LLO蛋白。结论已成功地在大肠杆菌中表达了rLLO蛋白,并进行了纯化,为进一步研究LLO蛋白的生物学功能及研制基于LLO蛋白的特异性诊断制剂奠定了基础。     

基于光敏技术的点光源跟踪系统的设计

本系统以MSP430F4270单片机为控制核心,用光敏电阻作为光源检测传感器,舵机构成执行机构,以舵机驱动激光笔水平或上下移动;由单片机根据光源传感器的信号,采用PID算法输出PWM波控制舵机带动激光笔指向光源.     

基于电涡流传感器的智能公交投币机性能改进

公交投币机在市场上得到广泛应用,但是现有智能公交投币机存在一些不足之处。研究通过应用微型直流电机,对现有的智能公交投币机进行改进,利用LM317控制投入的硬币通过电涡流传感器时的速度,并对软件进行修改,使智能公交投币机的硬币辨识率得到很大的提高。     

带钢重卷机组卷取机的纠偏系统

本文针对生产中存在的如钢卷边部不齐、错边现象,影响带钢质量的问题,在设计中通过采取带钢边部自动定位伺服纠偏系统,亦即EPC(edge position control)寻边系统的卷取机纠偏系统的方法,以及改变卷取机本身的机械结构和提高张力控制精度等办法,解决了钢卷边部不齐、错边现象,取得了纠偏精度提高,带钢质量增加的预期效果。     

基于LM/SVM方法的二次反应清洁汽油辛烷值预测

提出了一种莱文伯格—马夸特(LM)算法和支持向量机(SVM)有机结合的LM/SVM新算法,并将其应用于基于集总模型的二次反应清洁汽油研究法辛烷值的预测。借鉴复杂反应动力学研究中的集总方法,将汽油研究法辛烷值看成汽油饱和烃集总、烯烃集总、芳烃集总的函数,并采用支持向量机表达该函数。针对支持向量机参数及核函数参数难以选择的问题,通过莱文伯格-马夸特算法搜索支持向量机中的参数,并采取把训练集分割成工作样本和检验样本的策略,从而解决了过拟合的问题。利用经典测试函数对LM/SVM算法的性能测试结果表明:LM/SVM算法不但精度优于文献报道的遗传算法与支持向量机相结合的GA/SVM方法,而且其效率也远高于GA/SVM方法。LM/SVM方法对二次反应清洁汽油研究法辛烷值预测的相对误差绝对值的平均值为0.71%。     

LM339在数控电路中的应用

本文介绍了LM339在数控电路中的应用，并对其电路进行了分析。     

计算机的发展与结构设计

在计算机技术高速发展的今天,计算机被广泛的应用到结构设计领域,并为结构的设计质量和效率做出了突出贡献,但是也出现了许多质量问题。因此结构设计人员应该在设计过程中发挥起主导作用,而不是盲目的依赖计算机。     

Mechanical Properties and Bake Hardening Behaviour of two Cold Rolled Multiphase Sheet Steels subjected to CGL Heat Treatment Simulation

In recent years, multiphase steels have become a material of choice for use in the car manufacturing industry owing to their excellent mechanical properties. It is anticipated that in the years to come these steels will show the highest increase in usage. A particular aspect of their potential is that multiphase steels often show good bake hardening (BH) properties. The main factors that govern the microstructures and the properties of these steels are the chemical composition and the production process parameters. In this work two commercial cold rolled sheet steels with different carbon content were investigated. In order to produce dual phase (DP) steels with a ferrite‐martensite microstructure, the as‐received material was subjected to heat treatment simulating continuous galvanising line (CGL) cycles with an overageing zone before the zinc pot. After a first CGL cycle predominantly ferritic microstructures with small amounts of martensite, pearlite and retained austenite were obtained, which resulted in deviations from typical DP properties, e.g. in the occurrence of discontinuous yielding. A higher line speed led to improved mechanical properties. BH prestrain was varied between 0 and 10%. While only very little bake hardening was observed without prestrain, with increasing prestrain the amount of BH was evolving quickly towards larger values of more than 60 MPa. Generally, the BH values were somewhat larger for higher carbon content. Finally, an optimised CGL cycle was simulated at laboratory scale with changes in the process parameters. Thus, characteristic DP microstructures resulting in desired mechanical properties were obtained. For these optimised conditions, BH₂ values in excess of 60 MPa were achieved for both steels investigated.     

Application of Optimized BP Neural Network in Addressing for Garbage Power Plant

Neural network has the abilities of self-studying, self-adapting, fault tolerance and generalization. But there are some defaults in its basic algorithm, such as low convergence speed, local extremes, and uncertain number of implied layer and implied notes. This paper presents a solution for overcoming these shortages from two aspects. One is to adopt principle component analysis to select study samples and make some of them contain sample characteristics as many as possible, the other is to train the network using Levenberg-Marquardt backward propagation algorithm. This new method was proved to be valid and practicable in site selection of practical garbage power generation plants.