间歇减压精馏分离2-甲基吡啶/2-羟乙基吡啶

采用间歇减压精馏法实现了2-甲基吡啶和2-羟乙基吡啶这一热敏性混合物的分离,并考察了投料组成与操作压力对减压精馏过程的影响。结果表明,高真空条件降低了塔釜温度从而避免了物料在塔釜中受热变性,对于热敏物料2-羟乙基吡啶,减压精馏过程中压力应控制在4325 Pa以下,此时塔釜产品2-羟乙基吡啶的质量分数均能大于97%,同时收率能保持在86%以上。在压力为1325 Pa时,不同投料组成下塔顶产品2-甲基吡啶的质量分数和塔釜产品2-羟乙基吡啶的质量分数均高于98%,两者的收率也均在85%以上,能够很好地满足工业生产要求。     

真空间歇精馏法分离紫罗兰酮异构体

采用真空间歇精馏法实现了α-紫罗兰酮和β-紫罗兰酮异构体混合物的分离,考察了原料液组成、回流比、塔顶采出率、塔釜加热温度、塔节保温温度对异构体分离的影响,同时探讨了精馏操作时间对产品质量的影响。结果表明,在适宜的精馏操作条件下,塔釜产品β-紫罗兰酮的质量分数高于96%,同时收率能保持在90%以上,满足医药中间体应用要求。     

塔釜回流共沸精馏技术的研究

通过-个具有塔釜回流的精馏塔实验装置,以正己烷为共沸剂,从操作时间、回流比的控制、共沸剂的用量及实际应用等方面对塔釜回流共沸精馏技术分离乙醇-水共沸混合物进行了实验研究.研究结果表明:塔釜回流共沸精馏技术与常规共沸精馏技术相比,在其他操作参效相同,回流比大于3时,塔釜回流得到的产品纯度和收率有明显提高;达到同样的产品纯度和收率,塔釜回流所用的共沸剂量减少;但塔釜回流的操作时间延长.塔釜回流改善了常规的操作方式在生产应用上的不足.是一种很有应用前景的分离新技术.     

动态累积间歇精馏新操作方式研究

采用正丙醇-异丙醇混合物为分离物系,在动态累积间歇精馏理论基础上,提出了一种新的采用塔釜回流的操作方式,并在常规动态累积与精馏节能方面进行了对比。实验结果表明,在确保塔顶异丙醇产品纯度达到85%的条件下,节省了操作时间,进而可节约17%~33%的能耗,且收率提高1.5%~2.2%。     

带塔底储罐的间歇萃取精馏的实验研究

提出了带塔底储罐的间歇萃取精馏操作方式.新操作方式使精馏过程中加入的溶剂及塔内回流液直接流入塔底储罐,不再返回塔釜.以乙二醇为溶剂分离乙醇–水共沸物的实验研究表明,新操作方式克服了普通间歇萃取精馏塔釜体积庞大的缺陷,同时具有塔釜温度稳定、加热容易控制、收率提高等优点.     

真空间歇精馏法精制双环戊二烯的研究

采用真空间歇精馏技术精制聚酯级双环戊二烯中的双环戊二烯,考察了操作压力、回流比、塔釜和塔顶温度对双环戊二烯质量分数和收率的影响,优化得到较佳精馏操作条件.实验结果表明:适宜的工艺条件为塔顶压力9kPa,回流比为3,塔釜温度为68～106℃,塔顶温度为45～87℃,在以上条件下,产品中双环戊二烯质量分数达到96％以上,收率达到90％以上,为工业化提纯双环戊二烯提供了实验依据.     

减压间歇精馏制备δ-戊内酯新工艺的研究

以1,5-戊二醇为原料催化脱氢得到δ-戊内酯粗品,再采用减压间歇精馏工艺进行提纯,得到δ-戊内酯纯度为99. 8%、收率为95. 0%,产品质量达到了聚合级技术指标。减压间歇精馏工艺的操作条件为:压力5. 0 k Pa、塔顶温度140℃、回流比2. 5～3. 0。该新工艺能耗低、操作简便,工业化推广意义较大。     

真空精馏提纯对氨基三氟甲氧基苯的研究

采用真空间歇精馏技术对对氨基三氟甲氧基苯原料进行分离实验研究,考察了对氨基三氟甲氧基苯的热敏性;确定了安全的操作温度范围和适宜的操作策略。实验结果表明:采用变回流比操作,操作压力不超过5.0kPa,釜温低于140℃,产品中对氨基三氟甲氧基苯的质量浓度可达到99.5%以上,收率达到83.6%,其中各杂质的质量分数低于0.01%。     

真空间歇精馏提纯1,4-丁二醇生产残液

采用真空间歇精馏方法对从1,4丁二醇(BDO)生产残液中提取BDO的精制过程进行了研究.通过考察塔顶真空度、回流比和加热负荷等操作因素对分离效果的影响,确定了适宜的操作条件,塔顶压力为700 Pa,釜温在160～170℃之间,采用变回流比操作.结果显示,产品BDO的质量分数达到99.5％以上,收率80％以上.这种方法操...     

从香紫苏油中分离提纯芳樟醇和乙酸芳樟酯工艺的研究

采用真空间歇精馏技术,通过变换操作工艺条件,对香紫苏油进行分离得到芳樟醇和乙酸芳樟酯产品.考虑原料的热敏性制定出适宜的分离方案:首先在操作压力为1.5kPa条件下对原料进行初步分离,得到富含芳樟醇的轻馏分和富含乙酸芳樟酯的重馏分两个原料;再分别对轻馏分和重馏分进行不同条件下的真空间歇精馏,可以使芳樟醇的含量达到90.6%,乙酸芳樟酯的含量达到96.6%,满足两产品的不同需求.在提纯轻馏分中芳樟醇时,操作压力为5kPa,塔釜温度小于105℃;在提纯重馏分中乙酸芳樟酯时,操作系统压力为1.33kPa,塔釜温度低于110℃.此分离操作工艺,缩短了乙酸芳樟酯的受热时间、降低了分离温度以及乙酸芳樟酯因受热而异构化的趋势,降低了能耗.     

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.     

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.     

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.