基于专家PID的电镀行车速度控制系统

行车在电镀生产线中承担产品起吊及运转工作,其运行速度稳定性、精确性直接影响电镀生产效率。传统PID算法对大滞后、多扰动且难以建立数学模型的电镀行车自动化系统速度控制效果不佳。本文提出一种基于专家PID的电镀行车速度控制系统。该系统以可编程逻辑控制器为控制核心,根据电镀行车运行要求及工程专家的经验,建立专家控制器规则库,实现PID参数的优化修整,以确保行车运行速度符合工艺要求。实验结果表明：与传统PID相比,专家PID控制效果在超调量、响应速度、稳定性方面具有优势。     

基于可编程逻辑控制器的电镀生产线控制系统设计

电镀行车是电镀车间的主要设备,它事关整条电镀生产线的运行。通过将可编程逻辑控制器和变频器结合,减小电机启停时的电流冲击,避免行车定位不准确。该系统主要由硬件和软件两部分组成,可避免传统电镀行车的一些设计缺陷,提高自动化水平。     

电镀生产中的微机控制系统

结合我国电镀生产线的实际情况,论述了各类工业控制计算机在电镀生产中的利弊,简单介绍了一般电镀生产线对控制系统的要求。详细说明了以可编程逻辑控制器为控制中心的自动控制系统,给出了系统的硬件配置,并讲解了其控制原理。此控制系统在实际生产中运行良好,提高了生产效率,降低了劳动强度,并提高了产品质量。     

嵌入式电镀行车控制系统的设计与实现

传统电镀行车控制系统存在控制精度难以精准掌控和拓展空间受局限等缺陷。为了实现电镀行车的精准控制和平稳运行控制,同时赋予控制系统理想的适应性与拓展性,设计出一套基于ARM和FPGA架构的嵌入式电镀行车控制系统。介绍了设计方案,并阐述了控制系统的构架、逻辑控制流程及其实现方式。嵌入式电镀行车控制系统的信息采集和逻辑控制等均由独立模块分工完成,控制精度和稳定性得以保障。控制逻辑由软件构成,更改、调试方便,赋予控制系统自适应性与可拓展性。     

行车自动运行算法的应用和推广

主要论述了全自动电镀生产线的行车自动运行算法,通过对电镀生产线的自动化控制到电镀线的工艺,逐步深入到行车自动运行的算法。根据多年的编程的积累,对自动线算法进行了探讨,进而提高电镀生产线的生产效率,具有很高的实用性。     

基于PLC电镀生产线行车控制算法的研究

研究基于PLC电镀生产线行车控制算法,包括行车的手动和自动控制。     

铝合金电镀自动生产线带电入槽的实现

对采用U型龙门式吊车的电镀生产线所用的高频开关电源、可编程逻辑控制器的模块化程序及其他硬件进行分析,通过增加导通装置和改变整流器电流控制程序,实现带电入槽时具备施加斜坡电流的功能,从而满足铝合金无氰电镀工艺用自动生产线的要求,保证了镀件的结合力。     

基于可编程逻辑控制器的电镀工艺参数自动化监控

以可编程逻辑控制器(PLC)为控制核心,辅助相关执行元器件,对电镀过程中涉及的部分关键工艺参数实施自动化监控。分模块阐述了监控原理,并结合实验进行效果验证和评定。结果表明:应用PLC控制系统,可实现工艺参数自动化、实时、准确监控,并且可获得较理想的电镀质量。     

电镀行车的电动机动力部分的设计

一前言电镀生产线上的行车,需要能带动电镀件提升和推动行车水平行走的两套动力装置。动力装置部分包括电动机、变速器和制动机构。电动机通过变速器向驱动轴提供动力扭矩,制动机构附装于电动机上以有效地控制行车的动作。一般的电镀行车上动刀部分的设计往往有这么     

电镀生产中的PLC节能控制模型的设计研究

针对可编程逻辑控制器(PLC)控制为主的电镀生产中,存在能耗过高的问题。建立一种应用到电镀生产中PLC节能控制的模型。分析了在以PLC作为电镀生产控制核心的过程中产生能耗的原因,将监测到的各环节能损耗关系量化,在此基础上计算出电镀生产中的电能消耗最低时,镀铬槽的最优参数,并结合参数建立PLC节能控制模型。实验仿真证明,将PLC控制模型运用在电镀生产中,可以达到降低能耗的目的。     

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。