超声波辅助溶剂萃取印楝素条件优化

研究了以甲醇、乙醇、丙酮、乙腈、甲基叔丁基醚为溶剂在超声波辅助条件下萃取印楝素的工艺，利用高效液相色谱法进行快速测定印楝素含量，筛选出较佳萃取溶剂为甲醇。通过正交实验找到超声波辅助条件下甲醇萃取印楝素的较佳条件：料液比1：2；超声波功率设定200W；超声波作用时间设定为15min．此时印楝素萃取率达0．3792％。     

多溶剂萃取法精制印楝素的研究

对比研究了多溶剂萃取法与单溶剂萃取法精制印楝素的效果,并通过正交试验法选择了多溶剂萃取法精制印楝素的最佳试验条件为:萃取溶剂V(二氯甲烷):V(乙酸乙酯)1:5,分相液V(丙酮):V(水)1:1,V(萃取溶剂):V(分相液)10:3,该方法可将乙醇提取物中印楝素的质量分数从 3.68% 提高到 17.76%。多溶剂萃取法是一种简单高效的精制印楝素的方法。     

超临界CO2流体萃取印楝种子中印楝素的研究

印楝素(azadirachtin)是第一个从印楝Azadirachtaindica种子中分离出来的、目前世界公认的活性最强的植物源昆虫拒食剂，对害虫具有显著的拒食和生长发育抑制作用，印楝素主要存在于印楝种子中，印楝种子中含印楝素可达0．1％～0．9％(w)，为了从印楝种子中充分提取印楝素，本文建立了用超临界流体从印楝种子中萃取印楝素的方法，用正交试验优化设计选择萃取条件，最佳萃取条件为：温度35℃，压力30MPa，夹带剂用量每克印楝种子干粉1．5mL甲醇，提取率明显优于溶剂法。     

新工艺萃取印楝素及机理初探

用传统溶剂萃取、CO2超临界萃取、超声波强化萃取和微波辅助萃取从印楝种仁中提取印楝素，印楝素A的萃取率分别为0．3431％、0．2201％、0．3786％萃和0．5190％。结合萃取后残渣的电镜扫描结果，初步探讨了这四种萃取方法的萃取机理。     

印楝素的萃取及其杀虫活性

采用常规溶剂萃取、微波辅助萃取和CO2超临界萃取技术从印楝种仁巾萃取印楝素,以甜菜夜蛾为试虫对其室内杀虫潘陛进行了研究。结果表明萃取方法不同,印楝素的萃取率不同,其中以微波法萃取率为最高(0．52％);不同方法得到的印楝素的杀虫活性也不同,其中以超临界萃取物的活性最高,用药后7d的LC50为151．0μg／ml;印楝素严重影响试虫的生长发育,对幼虫的生长抑制率最高为89．6％。     

印楝种仁中印楝素含量的快速液相色谱分析

采用高压液相色谱法，微波辐射萃取种仁中的印楝素，对种仁中的印楝素含量进行快速定量测定，该方法的标准偏差为0．13,变异系数为0．13％，平均回收率为100．02％。     

超临界CO2萃取印楝种子中印楝素的研究

应用超临界CO2萃取技术从印楝种子中萃取印楝素，研究了萃取温度、压力和夹带剂对印楝素萃取效果的影响。当萃取温度为35℃、压力为15MPa、甲醇用量为CO2体积的3％时，可将印楝种子中90％以上的印楝素A萃取出来，所得产品印楝素A的质量分数为20．3％。     

快速浸出法提取印楝素浸膏

比较了微波法、超声波法、常规溶剂浸提法和快速浸出法4种方法提取印楝种子中印楝油、印楝素浸膏得率和浸膏中印楝素A、印楝素B的质量百分含量。快速浸出法提取总耗时0．5h,印楝油得率31．9％,印楝素浸膏得率3．39％,浸膏中AzadirachtinA含量8．99％、AzadirachtinB含量2．92％。快速浸出法耗时少,得率高,具有较多优势。测定了快速浸出法提取印楝素不同萃取时间下印楝种粉的粒度,发现物料粒度不断减小是达到快速萃取目的的一个重要因素。     

印楝素的快速提取法研究

采用微波辐射、超声波强化和快速搅拌三种辅助方法从印楝种仁粉中提取印楝油和印楝素。研究结果表明，快速搅拌法印楝油、二氯甲烷粗提物、印楝素A和印楝素B的提取率均高于微波辐射法和超声波强化法，具有明显的提取优势。     

超临界CO2萃取印楝种子中印楝素的研究

应用超临界CO2萃取技术从印楝种子中萃取印楝素,研究了萃取温度、压力和夹带剂对印楝素萃取效果的影响.当萃取温度为35 ℃、压力为15 MPa、甲醇用量为CO2体积的3%时,可将印楝种子中90%以上的印楝素A萃取出来,所得产品印楝素A的质量分数为20.3%.     

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。