基于推断策略多介质反应温度控制系统研究与实现

针对反应釜夹套多种热/冷介质温度自动控制检测硬件复杂、实现困难等问题,分析了夹套介质切换操作过程,提出了基于推断识别的夹套介质自动切换解决方案,最大程度地简化了系统硬件配置。通过记忆阀门操作推断识别夹套内当前介质,替代在线检测与分析物质成分检测系统。分析了影响压空时间的因素,关联了压空时间与压空用压缩空气压力的关系,并根据压空操作时间推断判定夹套介质压空终点,解决了传感器检测压空操作终点存在的问题。设计了基于推断识别的夹套介质自动切换控制系统,实际应用中克服了人工操作过程复杂、效率低和易出错等问题。实际应用表明,该方案介质切换的效率高、安全可靠。     

反应釜“崩套”事故原因浅析

１反应釜“崩套”事故反应釜（图１）是典型的传质、换热设备,物料的混合、反应均在釜体（１）内进行,夹套（２）内通以蒸汽或冷水用于对物料进行加热或冷却,以控制反应进程。在正常情况下,釜体（１）内压为－０．０７～＋０．０２ＭＰａ,夹套（２）内压力０．２～０．４ＭＰａ,因此,夹套（２）可视为内压容器。生产过程中,特别是夹套（２）处于加热—冷却之转折点附近时,反应釜夹套（２）之焊缝处会突然发生程度不同的漏水、漏汽,甚者好像夹套（２）猛然间“崩裂”了似的,习惯上称其为反应釜“崩套”事故。轻者造成停工停产,产…     

带夹套的反应釜温度控制器及LabVIEW实现

提出了一种带夹套的反应釜温度控制系统及控制方法:通过测温装置测得的反应釜和夹套内的实时温度,采用串级PID控制方法控制夹套内的温度,从而控制反应釜内的温度.     

化工生产中夹套容器内筒加强结构的设计

对于夹套内介质压力较高,内筒所受设计外压值较大的夹套容器,按常规加强圈的设计方法,内筒与夹套的间隙空间不能布置下满足设计所需要的加强圈,而且加强圈数量又很多,无法保证夹套内介质的流通顺畅,影响生产操作。对以上情况进行几种夹套容器内筒加强结构的探讨。探讨各种夹套容器夹套形式的优缺点。     

卧式反应釜螺旋导流夹套传热性能研究

利用FLUENT软件对螺旋导流夹套卧式反应釜的传热性能进行模拟计算,得出夹套冷却介质和内壁的温度变化以及流场分布状况,并对螺旋导流夹套与普通光壁内筒夹套的传热性能进行了比较。     

间歇反应釜降温过程的多目标控制

针对间歇反应釜降温时间控制困难的问题,提出一种基于间歇反应釜降温数学模型的控制方案。该方案依据热量守恒定律和传热速率方程建立间歇反应釜降温数学模型,通过控制间歇反应釜夹套入口冷媒的温度,进而实现对间歇反应釜降温时间的控制。为了实现反应釜在目标时间内降温至目标温度的多目标控制目的,采用了基于模型的开环控制闭环修正的控制策略,通过周期性修正间歇反应釜降温模型,实时调整夹套入口冷媒的温度,从而实现间歇式反应釜降温过程的多目标控制,提高了降温时间的控制精度。并通过实验证明该修正方法及控制方案是切实可行的。     

树脂合成工艺设备配置技术进展（Ⅱ）

2．3反应釜釜体结构的进展国内外迄今最主要的树脂合成反应釜结构见图6，称立式圆柱型夹套反应釜，材质为不锈钢、中碳钢衬搪瓷。釜内为微负压，夹套内为正压操作。属l－2类压力容器。随着反应釜容积日趋大型化，夹套给予的单位容积加热面积都在下降，而且随直径增大而降低甚多     

高效节能环保型聚四氟乙烯加热器

化工企业生产中使用的反应釜都是用钢壳外壁上的夹套来加热釜内介质,由于其热传递过程长,热阻大,而导致介质加热速度慢,时间长,高温上不去,热效率低等结果。针对上述问题,发明了一种高效、节能与环保型的聚四氟乙烯加热器,直接置于反应釜内加热介质,改变了原有的生产模式,从而达到了显著的节能、减排与增产的效果。     

氯化反应釜自动联锁控制技术

1系统说明 由PLC系统根据反应釜内的温度及出口压力,自动调节氯气控制阀门的开度,同时自动调节反应釜夹套冷却水回流阀门的开度,在设备及反应过程异常时,能有效的自动控制各阀门按照系统设计方案执行。通过PLC编程,组成一个智能化的多参数的自动控制系统,实现化学反应过程自动控制,优化工艺的目的。     

高效、节能、环保型聚四氟乙烯加热器(反应釜内专用)

多年来,国内外广大化工企业生产中使用的反应釜,都是用钢壳外壁上的夹套来加热釜内介质,由于其热传递过程长,热阻大,而导致介质加热速度慢,时间长,高温上不去,热效率又低等结果,从而抑制了工业生产的发展。作者针对上述问题,发明了一种高效、节能与环保型的聚四氟乙烯加热器,直接置于反应釜内加热介质,改变了原有的生产面貌,从而达到了显著的节能、减排与增产的效果。     

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.