挤出口型中混炼胶出口压力降的预测

阐明混炼胶于口型流动中挤出胀大比Ｂ与出口压力降ΔＰｅｘｉｔ之间基本上呈幂律关系。应用文献中提出的数学模型，预测了两种混炼胶于毛细管挤出过程中的ΔＰｅｘｉｔ值。结果表明．ΔＰｅｘｉｔ在末端压力损失中所占比例β随着剪切速率的增加而有所减小，β的平均值为１５％─１８％。     

聚合物短口型挤出胀大方程

研究了聚合物熔体经短口型挤出时的胀大行为及机理，并应用变流体微元分析方法，导出了短口型挤出胀大方程，即Ｂ＝〔１＋１．５（Ｌｅ／Ｄｃ）（△Ｐ０／τｗ）（ｎ＋１）ｔａｎ＾２α０〕＾０．５。同时，引进文献发表的混炼胶毛细管挤出实测值对该方程的简化式Ｂ＝〔１＋１．５（△Ｐ０／τｗ）（ｎ＋１）ｔａｎα０〕＾０．５进行了初步验证。结果表明，理论预测值与实测值有较好的一致性。     

热塑性塑料熔体剪切模量的预测

应用先前发表的出口压力降（△Ｐｅｘ）与壁面剪切应力（τｗ）的关系式，以及文献报道的几种热塑性塑料挤出流动中的△Ｐｅｘ和τｗ测量数据，估算了相应的熔体剪切模量（Ｇ）。结果表明，Ｇ随着τｗ的增加而呈线性函数形式增大。     

混炼胶长口型挤出胀大比的预测

研究了聚合物熔体于长口型挤出过程中的流变行为，提出了描述挤出胀大比与可回复切应变之间关系的数学模型：Ｂ＝（１＋ＳＲ＾２）＾０．２５。用此方程预测了混炼胶挤出膨胀行为，表明Ｂ的计算值与实测值为接近，二者之间相对误差的绝对值小于４％。     

LLDPE熔体在短口型挤出中末端压力损失

应用毛细管流变仪，考察了线性低密度聚乙烯（ＬＬＤＰＥ）熔体于短口型挤出流动中的末端压力及其影响因素。结果表明，入口压力损失（ΔＰｅｍ）与壁面处剪切应力呈指数函数关系；ΔＰｅｍ对温度的依赖性符合形如Ａｒｒｈｅｎｉｕｓ方程；ΔＰｅｍ随着口型直径的增加而减小；ΔＰｅｎ占末端压力损失（ΔＰｅｎ）８０％以上。     

SiCw增韧Al2O3／TiB2陶瓷复合材料的研究

根据对晶须与基体材料的热胀失配的分析，计算得出了Ａｌ２Ｏ３／ＴｉＢ２／ＳｉＣｗ三元复合材料中ＳｉＣｗ的临界体积分数。采用ＴｉＢ２颗粒增韧和ＳｉＣｗ增韧两种途径来改善Ａｌ２Ｏ３的脆性，得到此复合材料的抗弯强度为７４０ＭＰａ，断裂韧性为７．７ＭＰａ·ｍ＾１／２。分析表明：当ＳｉＣｗ含量大于临界体积分数时，强度大幅降低的主要原因是由于致密度的降低和热残余拉应力的增大。     

新型阴离子表面活性剂与十二烷基三甲基溴化铵的相互作用

本文研究了新型阴离子表面活性剂二氧乙基月桂醇醚羟丙基磺酸钠（Ｃ１２ＥＯＰＳ）与十二烷基三甲基溴化铵（ＤＤＴＡＢ）的复配体系，通过测定表面张力γ和ｃｍｃ计算了在这些体系中分子间的相互作用参数β＾ｍ和β＾ｓ及标准自由能ΔＧ＾０ｍｉｃ、ΔＧ＾０ａｄ。进而讨论了这些复配体系的增效作用。     

三氧乙基化十二醇醚磺酸盐与某些阳离子表面活性剂复配体系的表面…

本文研究了三氧乙基化十二醇醚磺酸钠〔Ｃ１２Ｈ２５ＯＣ２Ｈ４）３ＳＯ３Ｎａ，简称Ｃ１２ＥＯ３Ｓ〕与十六烷基三甲基溴化铵（ＣＴＡＢ），十二烷基三甲基溴化铵（ＤＤＴＡＢ）复配体系在纯水溶液中的表面活性，计算了１＝１复配体系胶束形成和表面吸附的标准自由能ΔＧ＾０ｍｉｃ、ΔＧ＾０ａｄ，及分子间相互作用参数β＾ｍ、β＾ｓ，揭示了两组分相互作用的强度和混合体系表面相及胶团的组成。     

油品芳烃含量对充油1,2—聚丁二烯橡胶流变性的影响

研究了油品芳烃含量为５１％～９０％时，充油１，２－聚丁二烯橡胶（１，２－ＢＲ）的流变性、门尼粘度ＭＬ＾１００℃１＋４、抗湿滑性和力学性能的变化规律。结果表明，在同一剪切速率γｗ下，高芳烃含量的充油１，２－ＢＲ与低芳烃含量的相比，表观粘度ηａ增大，流变曲线斜率小，非牛顿性较强。充油１，２－ＢＲ的ＭＬ＾１００℃１＋４、抗湿滑性及拉伸强度随油品芳烃含量的增高而增大。在相同γｗ下，充油１，２－ＢＲ的ηａ随     

高分子分了阳,分子量分布与熔体指数（MI）关系的研究（III）：熔体指数（MI）…

本文在前两篇的基础上用实验数据验证理论公式。结果表明ｌｏｇＭＩ与－ＢｌｏｇＭｗ＋ＣｌｏｇＭｗ／Ｍｎ之间有较好的线性关系，但本文从另一拓扑几何排列组合理论角度推导了文献上尚未出现的新公式，同样也用实验数据来加以验证，其结果表明ｌｏｇＭＩ与－ＢｌｏｇＭｗ＋ＣＭｗ／Ｍｎ之间的线性关系优于前一种关系。     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

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.     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

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.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009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、环氧树脂、不饱和聚酯树脂)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。