多晶硅尾气吸收影响因素研究

多晶硅尾气吸收单元主要分离还原尾气中的HCl和氯硅烷,降低尾气中HCl和氯硅烷含量,减小下游活性炭吸附的负荷.运用流程模型软件Aspen Plus对吸收过程进行模拟,对尾气吸收单元的喷淋吸收剂量、吸收剂组分、吸收剂温度、吸收塔压力和吸收塔的进气温度等各种影响因素进行模拟和灵敏度分析,得出尾气吸收的有利条件为温度-70～-65℃,压力1.0～1.2 MPa;适度增加吸收剂用量,改善吸收剂组分也有利于提高吸收效果.     

PVA醇解尾气吸收的模拟研究

在PVA生产过程中,醇解尾气含有一定量的醋酸甲酯和甲醇,现大多数的企业采用冷凝的方式进行回收,效果不理想。本文利用Aspen Plus软件,首先通过TDE热力学引擎获取实验数据,然后根据实验数据选取合适的热力学模型,最后通过采用Radfrac模块中的平衡和速率两种模型,计算出吸收剂用量和吸收塔填料层高度,对实际生产有一定的指导意义。     

环氧乙烷尾气吸收工艺的模拟与优化

针对污染物的最新排放标准,结合PROII模拟软件对环氧乙烷尾气吸收工艺过程进行了稳态模拟。通过单因素分析研究了尾气冷却温度、吸收剂进料温度及用量、吸收塔理论板数对吸收效果的影响,确定了优化后的工艺参数。在相同条件下,相比凝水吸收,乙二醇水溶液能明显降低吸收剂的用量,具有吸收剂利用率高、吸收后废液安全无毒、易处理等优势。     

二氧化碳气提法尿素装置中压吸收塔模拟分析

运用ChemCAD流程模拟软件对改进型二氧化碳气提法尿素装置的中压吸收塔进行了模拟分析,对吸收塔上段分别采用稀氨水和纯水为吸收剂时的两种工艺进行了模拟计算。模拟计算结果表明:吸收塔上段采用纯水吸收可使尾气氨排放得到有效控制,当纯水用量为80 kmol/h时,尾气中的氨摩尔分数从0.40%下降至0.02%,氨回收率可提高9.11%,年减少氨排放157.9 t。     

顺酐溶剂吸收装置工艺参数模拟优化与分析

采用Aspen Plus化工模拟软件10.0版本对顺酐吸收塔的吸收过程进行了模拟计算,考察了反应气进料温度、反应气中顺酐含量、循环吸收剂用量和循环吸收剂中水含量变化对塔顶尾气中顺酐含量和塔釜富顺酐吸收剂中水含量的影响规律。模拟计算结果和装置运行数据对比表明,在相同条件下,模拟值与装置运行值误差小于1%,说明该模拟方法可靠。为确保塔顶尾气中顺酐含量不高于0.02%（质量分数,下同）,塔釜富顺酐吸收剂中水含量不高于0.2%,同时降低后续装置操作负荷,模拟优化分析得到吸收塔适宜的工艺参数：反应气的进料温度为108℃,反应气中顺酐含量为2.36%,循环吸收剂的用量为反应气中顺酐质量的3.12倍。     

醇解废液处理工艺的探讨及开发

对现有醇解废液处理的工艺进行了分析并提出了一种新的醇解废液处理工艺，通过萃取精馏将醋酸甲酯提纯。再利用羰基化合成技术生产醋酐产品。该工艺技术创新，并且利用了电石炉尾气中的一氧化碳，产品附加值高，市场用量大，可实现经济效益与环境保护的双赢。     

新型悬浮法制备低醇解度聚乙烯醇的研究

低聚合度、低醇解度PVA在非纤维方面有着广泛的用途,且低聚合度、低醇解度PVA具有良好的生物降解性,可被作为生物降解材料。但一般的醇解方法很难制备得到低醇解度的PVA。我们首次采用新的分散聚合法制备低聚合度聚醋酸乙烯酯,再对低聚合度聚醋酸乙烯酯的悬浮醇解工艺进行了研究,分析了催化剂浓度、悬浮剂用量、反应物浓度等因素对醇解度的影响。     

建立环保装置减少尾气排放量

利用甲醇、甲酯、乙醛溶解于水,用水将醇解尾气中的甲醇、乙醛吸收后再放空,吸收液送回收工序进行回收处理。这不仅可降低甲醇消耗,提高醋酸收率;而且避免了因排放尾气中有机物含量超标对大气环境造成的污染。     

丙酮回收水吸收工艺模拟与优化

采用Aspen Plus流程模拟软件对丙酮回收水吸收工艺进行了模拟核算,模拟结果与实际生产数据吻合。在此基础上,针对吸收塔尾气排放温度低及吸收剂冷却器能耗高的问题,结合过程模拟分析提出了用吸收塔尾气来预冷却吸收剂的节能方法,对比了采用常规的间壁式换热器和冷回收塔2种工艺方案,并对冷回收塔方案进行了优化,得出了采用3.5 m高规整填料冷回收塔的优化工艺方案。文中依据优化方案对原工艺流程进行了改造,实施结果表明:在相同工艺条件下,吸收液的丙酮摩尔分数可提高9.93%,尾气排放温度从5℃提高到20℃,可回收冷量653.99 kW,吸收工艺的总能耗可降低30.77%。     

醇解废液处理工艺的探讨及开发

对现有醇解废液处理的工艺进行了分析，指出此工艺存在能耗高、产品附加值低等弊端。提出了一种新的醇解废液处理工艺，通过萃取精馏将醋酸甲酯提纯，再利用羰基化合成技术生产醋酐产品。该工艺技术创新，并且利用了电石炉尾气中的一氧化碳，产品附加值高，市场用量大，可实现经济效益与环境保护的双赢。     

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.     

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。     

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.     

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.