API串口通信在动力配煤控制系统中应用

通过介绍VC下的串口通信在动力配煤主从控制系统中的应用,进行了通信协议的制定,利用API函数设计上位机通信模块,完成了下位机参数的设置。较系统地阐述了用VC＋＋6.0开发上位机与基于DSP的智能调速控制器之间的串口通信程序的设计方法。     

基于PC机和单片机的主从式测控系统

采用MAX232芯片作为主从式测控系统上位机(PC机)与下位机(单片机)之间的电平转换单元,实现上、下位机正常对接的目的,并通过串口实现上位机与下位机之间的通信。Proteus软件的仿真测试结果表明:该系统能够实现对单片机的电机控制模块和交通灯控制模块的控制。     

Design of Master-Slave Control System Based on PC and MCU

采用MAX232芯片作为主从式测控系统上位机(PC机)与下位机(单片机)之间的电平转换单元,实现上、下位机正常对接的目的,并通过串口实现上位机与下位机之间的通信.Proteus软件的仿真测试结果表明:该系统能够实现对单片机的电机控制模块和交通灯控制模块的控制.     

航空试车台的电起动远程控制系统

航空试车台电起动远程控制系统以PLC300和WinCC作为控制器和上位机,通过S7-TCP/IP协议建立变量连接。介绍航空专用起动电源与PLC之间的Modbus串口通信,并通过PLC模拟量模块采集起动回路参数;对起动过程进行HMI组态,其电压电流曲线利于起动特性分析,参数实时显示便于操作人员在异常情况下及时做出决策。     

浅谈发动机背地控制或远程遥控

本文主要介绍一种串口通信远程控制系统,内嵌局域网通信系统,PLC通过串口由PC机进行控制。通过PLC控制变频器,输出三相交流电,实现对电动机的远程控制,而电动机根据相应的速度运行对发动机进行控制。     

基于VB的多路温度检测系统设计

为了实现温度的多点检测,采用传感器将温度数据转换为数字信号,以单片机为核心,读取并显示温度数据,同时采用RS485串行通信,使下位机测温模块与上位机实现双向通信,继而完成上/下位机的温度显示、报警及上位机报警控制等。上位机界面采用VB编写而成,作为系统中心,联络各下位机模块。由于RS458可以一对多双向远距离通信,多个下位机模块与上位机相连,实现常规温度（0～120℃）下的温度值多点远程监测。     

基于MicroBlaze软核的嵌入式最小系统

采用MicroBlaze软核构建嵌入式最小系统,给出其硬件设计方法,介绍了自主定制用户IP核的方法。同时给出了最小系统的软件设计方法和Bootloader软件流程图;加载μCOSII操作系统;通过串口与上位机调试软件通信;详细介绍了通信的流程,正确的通信结果证明最小系统适合产品开发的需要。     

基于单片机的直流电机调速控制

设计基于单片机的直流电机转速调速系统。以单片机为核心,加上测速、键盘输入及电机驱动等模块构成整个电机控制系统。对单片机内部资源和外围模块编程实现电机转速的采集和显示、键盘输入目标转速、内部运行增量式PID控制算法得到增量,根据增量对输出脉宽PWM占空比进行调制,使电机达到设定转速并匀速运转。PID控制是闭环控制,可以在转速偏离目标转速时快速调控。通过串口通信输出运行过程中的数据,进而对PID控制的参数进行整定。Matlab从串口接收数据并打印出PID调控曲线。实验验证了该系统能够实现实时控制电机转速调控的功能。     

注射成型智能监控系统的研究

提出了用于多台注塑机智能控制的群控系统方案,用一台PC机作为上位机并用其串行通讯口与下位机(多台注塑机)通讯控制注塑机,从而实现了主机智能监控从机的功能。利用MFC、数据库技术和Visual C 的通信API函数实现PC机人机交互界面和串口通信。详细介绍了该系统的基本组成及设计时的几项关键技术。     

卷曲机自动控制系统优化

卷曲机采用西门子S7-400PLC控制,系统通信方式选用Profibus-DP总线,与6SE70矢量变频器、PLC控制模块以及人机界面构成了底层硬件系统。通过模拟量模块参数优化、通信系统抗干扰优化、卷曲机控制模式运行优化等措施,实现了卷曲工序的集中管理和分散控制。     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料,介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。