防喘振控制在压缩机组中的应用

压缩机机组控制系统的现状,描述了压缩机机组控制系统通过利用ITCC综合控制系统的防喘振控制对压缩机机组的控制。     

丙烯腈装置机组防喘振控制系统

时某公司丙烯腈装置机组的防喘振控制系统进行改造,将三套机组现场指示控制联锁部分和室内监测系统改造为ITCC机组控制系统.优化改进后的丙烯腈装置机组控制系统投产至今,整个控制过程连续稳定、监控界面生动准确.     

解耦控制在单元机组中的应用

火电单元机组是一个具有强耦合的多变量控制系统。本文在火电单元机组控制系统数学模型的基础上,提出了单元机组被控对象多变量控制系统的解耦理论。分析了多变量解耦控制的基本原理,提出了多变量控制系统减少及消除耦合的方法。     

四大机组综合控制系统技改项目评价

针对川化股份有限公司引进合成氨装置四大机组控制系统和机械液压调速机构技术落后、运行维护成本高等问题,采用先进、专业的ITCC机组综合控制系统——TS3000和一体化的电液调速机构实现机组的综合控制及联锁功能,减少了故障发生几率,降低了机组的运行和维护成本。     

T6300压缩机控制系统在催化裂化装置中的应用(上)

介绍ICS Trusted的T6300压缩机控制系统在滨化催化裂化装置机组综合控制系统的应用,给出了机组的组成、系统硬件结构、通信和主要控制方案的设计实施。     

基于ADRC算法的供热机组智能安全控制系统研究

以300 MW供热机组安全控制系统分析及ADRC控制策略作为研究的切入点，本文首先分析了机组安全保护控制系统中燃气控制单元，然后在研究的过程中通过自寻优控制引入，使燃气锅炉运行系统达到最优化的状态。通过机组安全保护控制系统加入算法的实际运行结果能使燃气系统的调节更具灵活性。研究结果表明，机组安全控制策略，能使锅炉的控制系统研究变得更加具体化，借助于ADRC算法能够使机组安全控制更加智能化。     

ITCC在乙烯装置中的应用

在石油化工装置中,为透平压缩机组配置一套ITCC系统是非常重要的。ITCC控制系统为透平压缩机组实现连续操作过程中,在保持相同水平情况下能提供最大的可用率,并在一个集成的控制系统中就可实现速度控制、抽汽控制、压缩机防喘控制、性能控制、机组联锁保护和机组监测控制以及开停车顺序控制等多个功能。本文结合乙烯项目中机组控制系统(ITCC)的应用,重点介绍了TRICONEX公司的机组控制系统TS3000。     

输油管线泵机组监测及控制系统概述

输油泵监测控制系统是保证机组安全稳定运行的前提,对输油管线泵机组的各项监测,能够及时的发现运行中的异常、有效的保证机组平稳运行。本文对输油管线泵机组的结构,各个监测仪表和控制系统的功能进行了概述,并对各监测点出现报警联锁的可能原因进行分析。     

AP1000机组稳压器压力控制系统的研究与优化

稳压器压力控制系统是保证核动力装置安全可靠运行、提高机组可利用率的重要系统。通过对机组启动、正常运行、瞬态工况及事故工况等各阶段控制策略的全面分析,对各种控制设备的深入研究,再结合调试经验,完善了控制系统结构和控制策略,优化了关键设备选型和重要参数,提升了设备质量和可靠性。通过机组瞬态试验验证了系统的动态响应性能,对保障机组的安全稳定运行和提高机组的可利用率有重要的工程实践意义。     

快速锻造液压机液压控制系统研究

针对快速锻造液压机的特点,选用大流量比例阀构成机组液压控制系统,利用计算机和PLC组成现场控制网络来构建机组的控制系统,采用预测多模式模糊控制技术对快速锻造液压机的大惯量运动部件进行平稳、无冲击振动和准确的位置控制。经过多台快速锻造液压机的使用表明:该方法使控制系统的复杂程度大大降低,可靠性显著增强,机组的控制性能得到保证。     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

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.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009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、环氧树脂、不饱和聚酯树脂)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。     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

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.