正交试验法优选救必应中总黄酮的超声提取工艺

以芦丁为对照品计算总黄酮含量,通过单因素试验和正交试验考察不同因素和水平对提取工艺的影响;结果表明：最佳提取工艺为提取溶剂为40％乙醇溶液,料液比为1：70,超声仪工作频率为28kHz,提取时间为45min,该工艺简单易行,是提取救必应总黄酮物质的有效途径。     

正交试验法优化刺玫果总黄酮提取工艺

目的:为使刺玫果总黄酮更高效的提取出来,通过正交试验设计对刺玫果总黄酮提取工艺进行优化。方法:提取刺玫果总黄酮,采用正交试验、考察料液比、乙醇浓度、提取时间、提取次数对刺玫果总黄酮提取效果的影响,将总黄酮含量视为考察指标,选取最优提取工艺。结果:正交试验优化后提取工艺为:料液比1:10、醇浓度55%、提取时间2h、提取次数2次,总黄酮含量:27.41%。结论:由上述数据判断,正交试验实验次数少,数据点分布均匀,结论较可靠。     

辣木叶超微粉总黄酮提取工艺的优化研究

为了探究辣木叶超微粉中的总黄酮提取工艺,在单因素试验的基础上,通过建立四因素三水平的正交试验,分别考察乙醇浓度、提取温度、料液比、提取时间对辣木叶超微粉中总黄酮提取的影响,得出辣木叶超微粉总黄酮的最佳提取工艺条件。结果表明为:辣木叶超微粉总黄酮最佳提取条件为70%浓度的乙醇溶液作为提取剂,提取温度为80℃,料液比为1∶25,提取时间为1.5 h,测得总黄酮的含量为7.61%,比普通采用辣木叶为原料提取所得的总黄酮含量要高得多。     

芹菜叶中黄酮类化合物的提取与测定

文章以芹菜为研究对象,就其中总黄酮的提取分离和测定工艺进行了探讨。实验考察了单因素（提取溶剂浓度、物料比、回流提取时间和pH等）对总黄酮提取效果的影响,并在此基础上确定正交试验,得到了芹菜中总黄酮提取的最佳工艺条件∶40%（v/v）乙醇溶液,物料比（g/mL）1∶20,回流提取时间60 min,pH为6。得到总黄酮的含量为0.0794%。通过精密度实验和稳定性实验对测定方法进行评价。     

荔枝核黄酮类化合物的提取工艺研究

采用回流、热浸提、微波提取等工艺提取荔枝核黄酮类化合物,采用正交实验考察了提取溶剂浓度、提取时间、微波功率、提取温度、料液比等因素对提取率的影响,优选出不同工艺的提取条件。回流提取工艺的优化条件是:50%乙醇溶液,提取温度80℃,提取时间1h,料液比1∶10,提取3次,总黄酮得率为6.76%。热浸提工艺的优化条件是:50%乙醇溶液,提取温度70℃,提取时间1.5h,料液比1∶12,提取2次,总黄酮得率达到6.37%。微波提取工艺的优化条件是:60%乙醇溶液,微波功率700W,提取时间2.5h,料液比1∶25,总黄酮得率达到6.86%。     

破铜钱总黄酮的提取工艺研究

利用正交试验确定了破铜钱中总黄酮的最佳提取条件并测定了其含量。结果表明,用50%乙醇溶液,提取温度80℃,料液比1:30,提取时间1 h,提取效率较好,总黄酮得率为2.67%。     

甘草渣中甘草总黄酮提取工艺优化研究

用乙醇提取甘草渣中有效成分甘草总黄酮,以芦丁为标准品,采用紫外分光光度法测定甘草总黄酮,以得率为考察指标,采用正交实验优选提取工艺。结果表明,优选工艺为:药材粉末加20倍量浓度65%乙醇溶液,在60℃,超声功率250 W下提取1.5 h,提取2次。在此条件下,甘草总黄酮的提取率0.824%。     

甘草渣中甘草总黄酮提取工艺优化研究

用乙醇提取甘草渣中有效成分甘草总黄酮,以芦丁为标准品,采用紫外分光光度法测定甘草总黄酮,以得率为考察指标,采用正交实验优选提取工艺。结果表明,优选工艺为:药材粉末加20倍量浓度65%乙醇溶液,在60℃,超声功率250 W下提取1.5 h,提取2次。在此条件下,甘草总黄酮的提取率0.824%。     

超声波提取猴头菇总黄酮的工艺研究

以猴头菇为试验材料,设计单因素试验,探讨料液比、超声时间、超声温度及提取次数四个因素对猴头菇总黄酮提取率的影响,设计四因素三水平正交试验探索超声波提取猴头菇总黄酮的最佳工艺条件。结果显示超声波提取猴头菇总黄酮的最优工艺为:料液比1∶20 (g/m L)、超声时间90 min、超声温度70℃、提取次数为2次,总黄酮提取率为26.17%,RSD=2.38%。说明该超声波提取方法稳定可行,可用于猴头菇总黄酮的提取。     

正交法优化参苓白术散总黄酮的提取工艺

目的为深入研究参苓白术散现代临床功效,以确保药效的发挥,本试验进行参苓白术散总黄酮质量分数测定,正交试验筛选最佳提取方案。方法设计单因素试验,以乙醇的质量分数、用量和提取时间为优化条件,测定参苓白术散中黄酮的质量分数,并对提取工艺进行优化。结果参苓白术散总黄酮的最优试验提取工艺:乙醇质量分数为50%,提取时间2 h,乙醇用量25 mL。     

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.     

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。     

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.