电解质混合溶剂体系汽液平衡的推算

本文建立了由混合溶剂中电解质活度系数推算汽液平衡的数值计算方法。在电解质活度系数测定的盐浓度范围内,NaBr(1)-H_2O(2)-MeOH(3)和HCl(1)-H_2O(2)-MeOH(3)两体系在101.3 kPa下的汽液平衡计算结果与文献值平均绝对偏差分别为:汽相摩尔分率,平衡温度和,对前一体系还能正确地推测出交叉的盐效应规律。     

NH_3-H_3PO_4-H_2O体系汽液平衡的测定与热力学平衡计算

采用静态法测定了NH_3-H_3PO_4-H_2O体系在NH_3/H_3PO_4分子比为1.0-1.4,相应温度范围为75-175℃时的汽液平衡数据,并把实验数据关联成数学式.根据热力学理论,对NH_3-H_3PO_4-H_2O体系的热力学平衡计算的模型作了初步探讨.液相活度及活度系数采用扩充Pitzer方程,汽相逸度系数采用根据极性修改的RK方程.根据Edwards提出的弱电解质溶液的分子热力学,基于质量平衡、化学平衡、电荷平衡及汽液平衡理论,提出了NH_3-H_3PO_4-H_2O体系汽液平衡计算的热力学模型.计算结果表明:摩尔浓度低于25mol/kg H_2O时,模型计算结果与实验数据吻合得较好.     

NH_3-H_2O-N_2体系汽、液平衡的热力学计算(第二报)

在第一报中,我们提出了计算NH_3-H_2O体系的活度系数模型: lnγ_1=-a·e~(-b(x_1/x_2));lnγ_2=a/b[((b(x_1/x_2) 1)·e~((-b(x_1/x_2))-1)]。在此基础上,我们进一步研究了NH_3—H_2O—N_2体系在高压下的汽、液平衡。在不同的试验条件下:t=30～60℃、P=71～201大气压(绝)、XNH_8=0.3～0.9的范围内,测试了NH_3—H_2O—N_2三元系的汽、液平衡数据,並提出了从T.P.X计算y的电算框图,为大联尿水洗分氨NH_3-H_2O-N_2-H_2-Ar-CH_4六元系的计算,打下了基础。     

高压下NH_3-H_2O-CO_2-N_2-H_2五元系汽液平衡测定和计算

本文从实用目的出发,提供一个高压下NH_3-H_2O-CO_2-N_2-H_2五元体系汽液平衡计算模型.本模型结构为:(1)以NH_3-H-2O-CO_2三元系为基础,液相内的平衡运用分子热力学原理——离解平衡、电荷平衡、质量平衡三原则;并以Prausnitz提供的NH_3-H_2O二元系双曲正切函数活度系数模型为骨架,建立了宽广的氨水浓度范围内[NH_310一90%(mass)]的NH_3-H_2O-CO_2三元系的汽液平衡计算方法.(2)对于高压下NH_3-H_2O-CO_2-N_2-H_2五元系,汽相非理想性,本文用PHS状态方程计算汽相逸度系数.本模型的适用性已被实验测定值及文献数据所证实,实验值与计算值一致.     

挥发性弱电解质水溶液三元系的汽液平衡——NH_3-CO_2-H_2O,NH_3-H_2S-H_2O,NH_3-SO_2-H_2O体系

在Edwards通用性分子热力学模型中增加了三元相互作用项,应用优化若干可调参数的方法研究了弱电解质水溶液三元系的汽液平衡.编制了通用性FORTRAN计算程序PARA_9,在TQ-16机上实施.该程序具有弹性功能:可以直接计算,亦可优化参数.对NH_3-CO_2-H_2O、NH_3-H_2S-H_2O、NH_3-SO_2-H_2O三个体系进行处理获得满意结果,平均相对误差5—10%.同时给出了几组可调参数数值,并得到了溶液中离子和分子的活度系数,平衡浓度等有价值的信息.     

高压下氨水全浓度范围NH_3-H_2O-N_2-H_2-Ar-CH_4六元系汽液平衡热力学模型

本文提供一个高压下氨水全浓度范围的 NH_3-H_2O-N_2-H_2-Ar-CH_4六元系汽液平衡热力学计算模型。用扰动硬球状态方程(PHS)计算体系汽相逸度系数,用双曲正切函数型模型计算液相活度系数。作者用高压下的实验数据检验了 PHS 方程,并在全浓度范围的氨水文献数据考核了活度系数模型,证明本模型在温度15～76℃范围内具有良好的浓度及压力适应能力。     

高压下多元系中氨的溶解度测定及研究

本文提供了一个计算高压下氨、水有关体系汽液平衡的新方法:用浓氨水范围NH_3-H_2O二元系汽液平衡实验数据,求得氨及水的活度系数模型来表征液相的非理想性;用极性修正的SIRK状态方程来描述高压下汽相的非理想性.并进一步用本实验在高压下测得的NH_3-H_2O-N_2三元系及NH_3-H_2O-N_2-H_2-Ar-CH_4六元系中氨溶解度数据及Guerreri等发表的NH_3-H_2O-N_2-H_2四元系实验数据来考察本模型的可靠性,均获得了令人满意的结果,且本模型在高压下的计算精度和浓度适用范围,均优于Guerreri模型.     

高压下 NH_3-H_2O-N_2-H_2-Ar-CH_4六元系汽、液平衡的热力学计算(第三报)

在第一报(NH_3-H_2O体系)及第二报(NH_3-H_2O-N_2体系)的基础上,我们进一步研究了NH_3-H_2O-N_2-H_2-Ar-CH_4六元系在高压下的汽、液平衡行为。实验是在压力为120～300大气压(表压);温度为30°、40°、50°、60℃条件下,测定了该六元系的汽、液平衡组成。在热力学关联方面,我们是将NH_3-H_O-N_2三元系汽、液平衡热力学计算模型,进而推广应用到高压下NH_3-H_2O-N_2-H_2-Ar-CH_4六元系的汽、液平衡计算,实验证明计算结果是令人满意的,并推荐作为大联尿水洗分氨汽、液平衡计算的工程设计提供可靠的依据。     

25℃时CaO-P_2O_5-H_2O和MgO-P_2O_5—H_2O体系相平衡数据的计算

本文应用Pitzer电解质溶液理论建立了适合于CaO-P_2O_5-H_2O和MgO-P_2O_5-H_2O体系的活度系数关系式。通过对活度系数的关联,得到了这二个体系中的粒子相互作用参数值。计算了CaO-P_2O_5-H_2O和MgO-P_2O_5-H_2O体系在25℃时的相平衡数据。取得了较好的结果。     

含盐溶液汽液平衡预测(Ⅰ)——Pitzer模型的扩展及其在多元体系中的应用

本文提出一种新的预测含盐溶液汽液平衡的方法.对Pitzer(1980)模型进行扩展后,将其简化成单参数形式,推广至多元电解质溶液;经过适当假定,得到计算含盐挥发性强电解质和水体系及含盐水醇体系的活度系数公式,这些公式仅含二元相互作用参数;由二元溶液的活度关联出该参数后,可用于含盐体系各种温度下汽液平衡的预测.关联了40个二元电解质水溶液及7个电解质甲醇溶液298.15K时的简化Pitzer方程的单参数;用以推算6个水盐体系和2个甲醇盐体系在320-403K的蒸汽压,得到满意的结果,182个数据点的平均偏差小于0.65kPa;用以预测5个不同类型的含盐三元体系的等温、等压汽液平衡,所得的平均偏差对于汽相组成、沸点、压力分别为0.015、1K和1.92kPa.     

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。