盐析结晶法制取硝酸钾研究

硝酸铵与氯化钾复分解反应生产硝酸钾与氯化铵工艺，硝酸钾结晶率比较低，一般为45％-55％。为提高硝酸钾结晶率，研究了采用添加盐析剂的盐析结品法制取硝酸钾新工艺，通过盐析剂的盐析作用，硝酸钾与氯化铵在溶液中的有效浓度提高，从而使更多硝酸钾与氯化铵结晶析出，盐析剂始终在母液中循环并发生盐析作用。试验表明，盐析结晶法制取硝酸钾工艺可以使硝酸钾结晶率提高到80％。盐析结晶法制取硝酸钾最佯工艺条件：盐析剂添加量为硝酸钾量的40％（物质的量分数），硝酸钾结晶溶液质量分数50％～55％，硝酸钾冷却结晶终点温度为25℃，氯化铵溶液蒸发质量分数70％，氯化铵结晶终点温度55—65℃。     

超声波对生物大分子盐析的作用研究

在蛋白质-水胶体溶液中加入无机盐,利用蛋白质盐析的原理分离蛋白质。研究了不同频率超声波对蛋白质盐析的影响,证明超声技术可加速盐析速度。     

叔丁醇水溶液的盐析分离

叔丁醇水溶液用Ｋ２ＣＯ３进行盐析，可使叔丁醇提浓至９５％。多次盐析可显著减少盐用量。盐析分相后的盐水经蒸发浓缩后，可以作为盐析重复使用。     

NaCl盐析法从猪血粉水解液中提取L-亮氨酸

以NaCl为盐析剂从猪血粉水解液中盐析沉淀L-亮氨酸,确定了盐析沉淀所需的时间,考察了温度、pH值、NaCl加入量等因素对L-亮氨酸盐析沉淀率的影响。结果表明:盐析剂NaCl在原料液全溶解后搅拌半小时盐析沉淀率基本上达到最大值;低温对于盐析沉淀是有利的,工业生产中可在室温下或低温下进行;在溶液的pH值约为2时,NaCl存在下L-亮氨酸以二亮氨酸盐酸盐形式析出,沉淀率达到最大;溶液中氯化钠浓度越高盐析沉淀率越高,工业生产上可按0.35g/mL的比例加入NaCl。室温下控制猪血粉水解液的pH值为2,按0.35g/mL原料液的比例加入NaCl盐析出二亮氨酸盐酸盐,经精制得L-亮氨酸产品,产品符合《中华人民共和国药典》(2000年版二部)质量标准,L-亮氨酸的平均提取率为82.36%。     

盐析结晶法分离铬酸钾

关联了不同温度下K2CrO4在K2CrO4-KOH-H2O体系中的溶解度数据,分析了从K2CrO4-KOH-H2O体系中通过盐析结晶方式分离K2CrO4的可能性;通过K2CrO4-KOH-H2O体系中K2CrO4的盐析结晶实验,得出了初级成核现象发生时,体系的最大过饱和度与过饱和速率之间的动力学关系式及结晶过程中盐析剂浓度、盐析结晶终点K2CrO4收率、溶液体积等工艺参数间的关系,探讨了以KOH作为盐析剂,采用盐析结晶方法从K2CrO4-KOH-H2O体系中分离提纯K2CrO4的可行性,为K2CrO4的高效分离提供了一种新思路。     

盐析萃取应用于乙酸乙酯的提浓

采用盐析萃取应用于稀乙酸为原料制备己酸乙酯的提浓,对不同的萃剂比和含水不同的乙酸乙酯的盐析萃取效果进行了探讨,经盐析萃取可把乙酸乙酯含量提浓至96%以上.     

提高硝酸钾生产中产品结晶率研究

针对复分解法生产硝酸钾存在硝酸钾结晶率较低、成本高的缺点,本文选择了合适的盐析剂L,将盐析结晶技术应用于硝酸钾中试生产,确定了盐析结晶技术制取硝酸钾工艺流程及工艺条件。中试表明,采用盐析结晶技术可以使硝酸钾结晶率提高到78%,提高产量26%,降低蒸汽能耗25%。     

联合制碱法盐析结晶机理初探

根据盐析结晶的机理试验,模拟试验和中间试验结果,初步剖析了联合制碱法的氯化铵盐析结晶机理,提出了扩散传质,接触传质和液膜相变传质过程的机理模型,并指出在实际生产中,应尽可能强化扩散传质,抑制液膜相变过程,以改善盐析氯化铵结晶的质量,强化生产。在此基础上分析了影响盐析结晶生长的各种因素,提出了优化操作的条件。     

盐析萃取应用于乙酸乙酸的提浓

采用盐析萃取应用于稀乙酸为原料制备乙酸乙酯的提浓，对没的萃剂比和含水不同的乙酸乙酯的盐析萃取效果进行了探，经盐析萃取可惭酸乙酯含量提浓至９６％以上。     

盐析法由卤水制备纯碱的新工艺

卤水与碳酸氢铵反应生成碳酸氢钠结晶和氯化铵溶液,碳酸氢钠的结晶率是70%～79%.为了提高碳酸氢钠的结晶率,研究了采用加入盐析剂的方法,通过盐析剂的盐析作用,使碳酸氢钠的溶解度降低,从而更多地结晶析出.实验确定选择高沸点的盐析剂D,使结晶率提高到90%以上.通过正交试验研究,得到盐析法的适宜工艺条件:盐析剂与氯化钠物质的量比为1.0∶ 1.0,反应温度35 ℃,碳酸氢铵与氯化钠的物质的量比为1.0∶1.0,反应时间120 min.     

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。