水-丙酸二元体系汽液平衡的热力学性质

用新型泵式沸点仪测定了在101.325kPa下水-丙酸二元系在不同液相组成时的沸点,用过量自由焓函数Q,采用间接法由Tpx推算了水-丙酸二元系的汽相平衡组成y。汽相的非理想性用截至第二项的维里系数的状态方程求出汽相混合物中组分逸度系数。二元体系活度系数的关联分别用Wilson模型、NRTL模型、Margules模型和vanLaar模型进行关联,用最小二乘法求出了它们的液相活度系数模型参数。用所得的液相活度系数来计算三个二元体系的过量吉布斯自由焓函数GE/RT。计算的泡点温度与实验测得的沸点温度吻合良好,由面积积分法检验这些模型参数计算的二元体系相平衡数据,得到很好的热力学一致性。     

甲醇-乙酸、甲醇-丙酸和乙酸-丙酸二元体系汽液平衡

用新型泵式沸点仪测定了101.325 kPa下甲醇-乙酸、甲醇-丙酸和乙酸-丙酸3个二元系在不同液相组成时的沸点,用过量自由能函数Q,采用间接法由Tpx推算了3个二元体系的汽相平衡组成y。3个二元体系活度系数分别用Wilson模型、NRTL模型、Margules模型和Van Laar模型进行关联,用最小二乘法求出了它们的液相活度系数模型参数。用所得的液相活度系数来计算此二元体系的过量吉布斯自由能函数GE/(RT)。用3个二元系模型参数对所测的数据进行关联,建立该系统汽液平衡的热力学模型并计算平衡时的泡点温度。计算的泡点与实验的沸点吻合良好,经面积积分法检验,这些模型参数计算的3个二元体系相平衡数据具有很好的热力学一致性。     

甲醇-乙酸-丙酸多元体系汽液平衡

用新型泵式沸点仪测定了在100kPa下甲醇-乙酸、甲醇-丙酸、乙酸-丙酸3个二元体系以及甲醇-乙酸-丙酸三元系在不同液相组成时的沸点,并用间接法T-p-x(温度、压力和液相摩尔分数)推算了3个二元体系的汽相平衡组成。3个二元体系活度系数分别用Wilson模型、NRTL模型、Margules模型和van Laar模型进行关联,用最小二乘法求出了它们的液相活度系数模型参数,同时,用这些模型参数来计算它们的汽相摩尔分数。所得的液相活度系数来计算3个二元体系的过量吉布斯自由能函数,且所研究的所有体系中各组分之间不存在共沸点。用3个二元体系Wilson模型参数对所测的三元体系数据进行关联,建立该系统汽液平衡的热力学模型并计算平衡时的汽相摩尔分数和泡点温度。由面积积分法检验这些模型参数计算的3个二元体系相平衡数据,得到很好的热力学一致性。     

二甲基硫醚-二硫化碳-甲醇体系等压汽液平衡

用泵式沸点仪测定了100 kPa下二甲基硫醚-二硫化碳、二甲基硫醚-甲醇2个二元系以及二甲基硫醚-二硫化碳-甲醇三元系在不同液相组成时的汽液平衡数据,用Wilson、NRTL、Margules和van Laar模型分别对2个二元系活度系数进行关联,用最小二乘法求出其液相活度系数模型参数,用这些模型参数来计算其汽相组成y,根据过量Gibbs自由能函数Q(GE/RT),采用间接法由Tpx推算了2个二元系的汽相平衡组成。用所得的液相活度系数计算2个二元系的过量吉布斯自由能函数GE/RT,并由2个二元系与三元系回归出二硫化碳-甲醇二元系的NRTL模型参数。用3个二元系NRTL模型参数对所测的三元系数据进行关联,建立三元系汽液平衡的热力学模型并计算平衡时的汽相组成y和泡点温度。分别由Herington法和McDermott-Ellis法对2个二元系和三元系进行热力学一致性检验,结果表明这些相平衡数据满足热力学一致性。     

甲胺与水多元系常压汽液平衡研究

用新型泵式沸点仪测定了常压下一甲胺-二甲胺-三甲胺-水四元系在不同液相组成时的沸点;由所测的甲胺-水二元系数据,用过量自由焓Q函数间接法推算了与之平衡的汽相组成,再用最小二乘法求出甲胺与水间二元体系的液相活度系数模型参数：甲胺与甲胺间二元体系的液相活度系数模型参数则通过拟合它们与水构成的三元系获取;由所得的最佳二元系参数用于该体系四元系汽液相平衡数据的预测,将计算的泡点与实验测得的沸点作了比较,结果表明两者吻合良好。     

二甲基硫醚-吡啶-N,N-二甲基乙酰胺体系汽液平衡关联和预测

在101.325 kPa下用沸点仪测定了二甲基硫醚-吡啶、二甲基硫醚-N,N-二甲基乙酰胺、吡啶-N,N-二甲基乙酰胺3个二元体系以及二甲基硫醚-吡啶-N,N-二甲基乙酰胺三元体系不同液相组成时的汽液平衡数据,3个二元体系活度因子分别用Wilson、NRTL、Margules、van Laar和UNIQUAC模型进行关联,用最小二乘法求出了它们的液相活度因子模型参数,用这些模型参数计算它们的汽相组成。根据过量Gibbs自由能函数,采用间接法由Tpx预测了3个二元系的汽相平衡组成。用所得的液相活度因子计算3个二元体系的过量Gibbs自由能。3个二元体系的Wilson、NRTL、Margules、van Laar和UNIQUAC模型参数分别对所测的三元体系数据进行关联,建立该系统汽液平衡的热力学模型并计算平衡时的汽相组成和泡点温度。分别由Herington法和McDermott-Ellis法对3个二元体系和三元体系进行热力学一致性检验,结果表明这些相平衡数据满足热力学一致性。     

Correlation and prediction for vapor-liquid equilibria of dimethyl sulfide-pyridine-N,N-dimethylacetamide muiticomponent system

在101.325 kPa下用沸点仪测定了二甲基硫醚-吡啶、二甲基硫醚-N,N-二甲基乙酰胺、吡啶-N,N-二甲基乙酰胺3个二元体系以及二甲基硫醚-吡啶-N,N-二甲基乙酰胺三元体系不同液相组成时的汽液平衡数据,3个二元体系活度因子分别用Wilson、NRTL、Margules、van Laar和UNIQUAC模型进行关联,用最小二乘法求出了它们的液相活度因子模型参数,用这些模型参数计算它们的汽相组成.根据过量Gibbs自由能函数,采用间接法由Tpx预测了3个二元系的汽相平衡组成.用所得的液相活度因子计算3个二元体系的过量Gibbs自由能.3个二元体系的Wilson、NRTL、Margules、van Laar和UNIQUAC模型参数分别对所测的三元体系数据进行关联,建立该系统汽液平衡的热力学模型并计算平衡时的汽相组成和泡点温度.分别由Herington法和McDermott-Ellis法对3个二元体系和三元体系进行热力学一致性检验,结果表明这些相平衡数据满足热力学一致性.     

甲基二氯硅烷+甲基三氯硅烷+二甲基二氯硅烷+苯多元系常压汽液平衡研究

卤代硅烷的相平衡数据为硅烷生产所需,而这方面的研究又较缺乏,尤其是甲基乙烯基二氯硅烷生产中所需的汽液相平衡数据尚未见报道.今用新型泵式沸点仪测定了常压(101.325 kPa)下甲基二氯硅烷 甲基三氯硅烷 二甲基二氯硅烷 苯四元系及其四个三元体系和六个二元体系在不同液相组成时的泡点.由所测的二元系数据,用过量自由焓Q函数间接法推算了与之平衡的汽相组成.再用最小二乘法求出二元体系的最佳配偶液相活度系数模型参数.所得的六组最佳二元系Wilson模型参数符合热力学一致性,并用于该体系三元和四元系汽液相平衡数据的预测,将计算的泡点与实验测得的泡点作了比较,其拟合精度良好,关联结果令人满意,硅烷二元系、多元系的热力学模型及VLE数据可为该体系的分离设计提供必要的理论依据.     

水-乙醛-乙酸三元系等压汽液相平衡研究

采用非分析法,在拟静态条件下,用泵式沸点仪测定了101.3 kPa下水-乙醛-乙酸三元系在不同液相组成时的沸点;不考虑乙醛与活性组分的化学反应,采用“乙醛虚拟饱和蒸汽压”的处理方法,仅用传统的Wilson活度系数模型,通过最小二乘法,由水-乙醛-乙酸三元系汽液平衡实验数据拟合出乙醛-乙酸二元系的液相活度模型参数;将求出的二元系最佳模型参数用于水-乙醛-乙酸三元系及乙醛-乙酸二元系泡点温度和汽相组成的推算,其结果与实验值、文献值比较,均获得较满意的结果。     

缔合体系汽-液相平衡的研究(Ⅱ)——三元缔合体系汽-液相平衡的研究

本文提出了多元缔合体系汽-液相平衡的热力学模型,并用其计算了缔合体系水-甲酸-乙酸、水-乙酸-丙酸、水-甲酸-丙酸及甲酸-乙酸-丙酸在760mmHg下的实验液相活度系数。活度系数的计算值由Wilson方程或McCann方程给出。由相应二元体系的汽-液相平衡数据对三元体系的沸点及汽相组成进行了预测。结果表明,预测值能较好地同实验数据相吻合。     

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.