南瓜叶黄酮类化合物提取条件的优化

以乙醇浓度、浸提时间、固液比以及浸提温度等条件对南瓜叶总黄酮的提取进行正交设计试验,并以芦丁为标准品,用分光光度法在506nm处测定各提取液的总黄酮含量。结果表明,乙醇提取法的最佳工艺条件是：乙醇体积分数80％,提取时间3h,固液比1g：30mL,提取温度70＂（2,此时南瓜叶总黄酮的平均含量为2．89％。研究结果可为利用南瓜叶工业化生产黄酮类药用成分提供科学依据。     

穿心莲总黄酮乙醇提取工艺的研究

研究了穿心莲中总黄酮的乙醇提取工艺。以穿心莲中总黄酮质量分数为考查指标,通过单因素实验和正交试验,考查提取温度、乙醇质量分数、固液比、提取时间对总黄酮质量分数的影响。确定最佳工艺条件为：提取温度50℃,提取时间2h,乙醇质量分数60%,固液比1∶20。     

超声辅助提取新疆甘草总黄酮工艺研究

目的：建立新疆甘草中总黄酮最优提取工艺。方法：利用NaNO₃-Al(NO₃)₃-NaOH分光光度法测定新疆甘草中黄酮的含量,通过超声提取,分别考察不同料液比、超声功率、提取温度、提取时间及乙醇浓度对新疆甘草总黄酮提取效率的影响,根据单因素实验结果,设计正交实验对提取工艺进行优化,最后进行验证实验。结果：新疆甘草总黄酮最佳提取工艺条件是料液比1∶15、乙醇体积分数80%、提取温度80℃、提取时间10 min、提取功率630 W。结论：新疆甘草中总黄酮性质稳定,此提取工艺简单方便,有效地节约原材料以及缩短提取时间,对于甘草中黄酮的提取更适用。     

中草药叶上花黄酮提取方法研究

采用定性检测、光谱分析等方法对叶上花总黄酮的种类与提取方法进行了研究。结果显示叶上花所含黄酮种类较多、含量较高;各因素对总黄酮提取率影响程度大小顺序为温度〉乙醇体积分数〉固液比〉时间。最佳提取条件为温度60℃、乙醇体积分数70%、固液比1∶100（g/mL）、提取时间180min,在此提取条件下,总黄酮含量为1.479%。     

微波辅助法提取甘草中总黄酮的研究

研究了以水-乙醇混合溶剂为提取剂，在微波条件下提取甘草中总黄酮的工艺条件，探讨了乙醇浓度、提取时间、固液比和微波功率对提取率的影响。结果表明：采用70％的乙醇，固液比为1：12，在中低档火力下微波提取120s，总黄酮得率为3．84％。     

正交实验优化异甘草素超声提取工艺

采用超声法提取乌拉尔甘草中异甘草素,通过乙醇体积分数、液固质量体积比(g/mL)、超声提取时间和提取次数4个因素对异甘草素提取率的影响进行了正交实验,确定超声提取最佳工艺条件为:体积分数80%乙醇,液固质量体积比(g/mL)10∶1,超声20 m in,提取3次,异甘草素的提取率为0.37‰,是乙醇热回流提取的2.06倍,是索氏提取的1.54倍。超声提取浸膏中异甘草素的质量分数为0.55%,是乙醇热回流提取的3.24倍,是索氏提取的1.45倍。结果表明:超声提取甘草中异甘草素具有提取温度低、速度快、提取率高、纯度高等特点。     

陕西产绞股蓝总黄酮提取工艺研究

以陕西产绞股蓝为原料,采用乙醇回流法提取绞股蓝中总黄酮.考察了提取溶剂、温度、时间、次数和料液比对绞股蓝总黄酮得率的影响,并进行正交试验优化.结果表明:绞股蓝总黄酮最佳提取工艺为料液比1:30(g·mL-1),提取温度80℃,乙醇体积分数70％,回流提取2次,每次1 h,该条件下的绞股蓝总黄酮得率为7.91％.     

响应面法优化闪式提取甘草叶总黄酮工艺研究

通过响应面法分析并优化了甘草叶总黄酮的闪式提取工艺,确定最佳工艺条件为:乙醇体积分数70.2%、液固比40.3∶1、提取时间5 min,在此工艺条件下总黄酮的提取率高达2.91%,与模型预测值基本相符.结果表明闪式提取法是一种高效、快速提取甘草叶中总黄酮的方法.     

桑叶黄酮多酚类物质提取优化试验

采用正交实验法（采用b（34））对桑叶中黄酮多酚类物质提取条件进行了分析,优化乙醇浓度、料液比、提取时间和温度等因素对桑叶中总黄酮与桑多酚提取率的影响。结果表明：当料液比1：60,乙醇体积浓度60％,提取温度100℃,提取时间2．5h,从桑叶中提取的总黄酮与桑多酚的提取率达最高。     

微波辅助提取花生壳总黄酮的工艺优化

以花生壳为原料,采用微波辅助提取花生壳中的总黄酮。探讨了乙醇体积分数、微波时间、料液比和提取温度对总黄酮提取的影响。在单因素的基础上,通过正交试验优化工艺。结果表明,最佳提取工艺条件为:微波时间2min,提取温度50℃,乙醇体积分数70%,料液比1∶25(g/m L),在此工艺条件下,花生壳总黄酮的提取率为8.9436%。     

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。