超声强化超临界CO2萃取除虫菊酯的初步研究

本文在超声场中用超临界CO2萃取除虫菊酯，研究超声场对超临界流体萃取固体植物中有效成分的影响．结果表明在实验范围超声场的存在能有效地提高萃取速率，且又不引起超临界CO2空化，从而没有引起除虫菊酯的降解。     

超临界CO2破碎生姜细胞壁萃取精油

采用超临界CO2萃取生姜精油,设计了一个突然降压的过程,使生姜块茎的细胞壁破碎,减少过程的传质阻力。通过L18(37)正交试验得出其最优的工艺条件为:破碎压力20.0MPa,恒压时间30min,降压速率为10.0MPa/min,萃取压力16.0MPa,萃取温度45℃。在CO2流量为20.0m3/h时,萃取60min可完成操作。与索氏(溶剂)提取法相比,其收率很高(约3.62%);与超临界CO2萃取法相比,该方法的萃取温度、萃取压力和操作时间有较大降低,产品收率提高1.32倍;据此设计的150L中试装置,经过4000h的试运行证明,该装置用于萃取姜油可完全满足工艺要求。     

超亚临界态CO2萃取除虫菊酯浸膏的研究

采用超亚临界态CO2 萃取技术 ,从除虫菊花中提取了除虫菊酯浸膏 ,通过正交试验方法得优化萃取工艺条件为 :萃取压力 2 0MPa ,萃取温度 2 5℃ ,CO2 气速 10 0HL/h ;研究了在用水作夹带剂的作用下对提取效果的影响 ,实验表明夹带剂可以增强萃取效果     

超临界CO_2和微波辅助萃取当归挥发油

考察当归挥发油的不同提取方法。文中用超临界CO2流体萃取法和微波辅助萃取法研究萃取当归挥发油。实验表明:超临界CO2萃取最佳工艺条件为萃取压力25 MPa、分离釜Ⅰ解析温度55℃、萃取温度45℃,提取率约1.9%;微波辅助萃取最佳工艺条件为无水乙醇为提取溶剂,微波功率800 W、微波辐射时间150 s、液料质量比为4.71∶1,提取率约11.2%。微波辅助萃取法取得当归油的收率高于超临界CO2萃取法。微波辅助萃取法萃取当归挥发油收率高,但外观品质较超临界萃取的当归挥发油差。     

超临界萃取法制备辣椒红色素

将原料干红辣椒采用溶剂法提取出辣椒树脂中间产品,并以其为原料进行了超临界CO2制备辣椒红色素的实验研究。通过对超临界萃取压力、温度、时间与装料系数的相关实验研究,确定出超临界CO2萃取法制备辣椒红色素的工艺条件。研究结果表明,最优工艺参数为:萃取压力20 MPa,萃取温度35℃,萃取时间6 h,装料系数0.7。制取的辣椒红色素产品符合中国国家标准,主要指标色价、己烷残留等均优于国标要求。     

超临界CO_2萃取浓缩大豆粗磷脂的研究

以浓缩大豆粗磷脂作为液态物料的模型材料进行了超临界CO2萃取研究。通过实验考察了萃取温度、压力、时间和溶剂流量等对萃取效果的影响,确定了对于该种物质萃取的最佳操作条件。通过与传统的水蒸汽蒸馏法和有机溶剂萃取法生产的产品进行对比(酸碱度、含水量、有机溶剂残余量、色泽、气味等方面),表明了超临界流体萃取技术用于热不稳定物质的萃取所具有的独特优势。     

超临界CO_2萃取辣椒油实验研究

研究了利用超临界CO2为萃取剂,从辣椒中萃取分离辣椒油的工艺。考察了萃取压力、萃取温度、辣椒原料颗粒大小以及CO2流量等因素对辣椒油萃取率的影响。结果表明,最佳工艺参数为:压力22 MPa,CO2流量0.3~0.4 m3/h,颗粒度30~50目,温度315 K。超临界萃取法具有工艺简单、操作安全、产品无溶剂残留、提取率高等优点。     

超临界CO2萃取率影响因素的研究

本文探讨了超临界CO2萃取的温度，压力，CO2流量以及加入助溶剂对萃取率的影响。     

超临界CO2萃取花椒化学成分的研究

本文研究超临界CO2对花椒化学成分的萃取,并通过正交实验确定最佳工艺条件为:萃取时间1.0h,温度45℃,压力33MPa,并探讨了夹带剂对萃取结果的影响。用气相色谱质谱联用(GC-MS)对超临界CO2萃取的花椒化学成分进行了研究。结果表明,超临界CO2萃取法具有提取率高、萃取成分全面、提取时间短、无溶剂残留等优点。     

微波强化超临界CO2萃取杜仲叶中桃叶珊瑚苷工艺研究

目的：优选萃取杜仲叶中桃叶珊瑚苷的最佳工艺条件。方法：以杜仲叶中桃叶珊瑚苷的提取率为指标，采用正交试验考察了4种因素萃取压力，萃取时间，微波功率，提取温度对桃叶珊瑚苷提取的影响。结果：正交试验考察优化的结果为：萃取压力：20Mpa，萃取时间：30min，微波功率：600W，提取温度35℃。结论：与传统溶剂萃取法相比，微波强化超临界CO2萃取能大大节省提取时间、提高产品的收率和杜仲叶的利用率、防止活性成分的分解或降解。     

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。