铅盐热稳定体系的硬质PVC排水管件粉料注射工艺的研究

通常单螺杆注塑机只能采用粒料来生产PVC排水管件。本人在研究管件配方过程中,着重改善了物料的内、外润滑作用,提高粉料在料筒的塑化效果,实现采用粉料注射工艺来生产排水管件的目的。     

江西伟虹PVC管材项目建成

江西伟虹管业有限公司PVC管材项目2013年1月5日建成试投产。该项目投资1.2亿元,采用国内领先的塑胶挤出生产线、注塑机和模具,主要生产PVC系列的给水排水管材、管件、绝缘电工套管、配件及各种通讯电缆用护管等产品。项目全部建成后,生产线可达52条,将形成年产10万t PVC管材的生产能力,年销售收入4亿元。     

注塑用聚氯乙烯干混粉料流变性能的研究

用国产注塑机直接采用聚氯乙烯(PVC)干混粉料注塑硬质聚氯乙烯(RPVC)管件是一个新课题。本文着重介绍在美国哈克(HAAKE)EU-5型转矩流变仪上筛选配方,对PVC干混粉料在加强稳定化、阻止热分解、改善加工性能和实现内外润滑的平衡等方面,进行初步探讨;同时结合生产实践,阐述了干混粉料的制备,机筒模具温度、塑化注塑压力等工艺全过程的控制条件,以及注塑管件在出现缺陷时的解决办法。     

PVC管件模具的材质选择与结构设计

为延长模具使用寿命,降低维修、保养费用,根据PVC管件的生产特点,分析了如何选择PVC管件模具型腔、型芯材质以及合理设计模具结构。     

生产耐压PVC-U注射管件的影响因素分析

分析了管件耐压性能的重要性 ,讨论了设备、模具、配方、工艺对生产耐压PVC -U注射管件的影响     

大型PVC-U供水管件的研制

以聚氯乙烯(PVC)为基体,加入热稳定剂、润滑剂、抗冲击改性剂等,经挤出造粒制得用于生产大型硬质PVC(PVC-U)供水管件的PVC—U材料。并用该材料生产了PVC-U供水管件。测试结果表明,该PVC-U材料具有良好的力学性能、成型加工性和热稳定性,管件性能达到相关技术标准要求。     

泰瑞全新推出节能型注塑机

作为国内领先的注塑机制造商，泰瑞机器制造（中国）有限公司（以下简称“泰瑞”）具有年产4000台注塑机的生产能力，客户遍及世界71个国家和地区。该公司以产品种类丰富、交货及时且服务周到而为业界所认可。其产品包插TRX系列热塑（热固）注塑机，锁模力60～4000t；TRX—M系列伺服节能注塑机，锁模力60～1000t；U（C）PVC、PPR和PE塑料管件专用注塑机PET瓶坯高速机、瓶盖高速机及相关生产线双（多）色、夹层（发泡）注塑机；多回路（电液复合）快速注塑机；气体辅助射出成型系统；各类配套模具和辅机。     

PVC管材卫生安全性能可以信赖

厦门建材行业协会专门召开了PVC给水管材、管件卫生安全性能研讨会，会上来自中塑协、厦门市质监局、疾控中心等部门的专家们认为：正规厂家生产的、符合国家卫生标准的PVC管材、管件都可以放心使用。     

多级注射成型工艺在PVC-U管件生产中的应用

通过对多级注射成型工艺特点的分析，给出多级注射工艺的特性曲线；结合多级注射成型工艺在硬聚氯乙烯（PVC－U）管件加工中的应用，总结出PVC－U管件加工中多级注射工艺流程特性曲线的特点，举例说明了多级注射成型工艺的使用方法，提出了PVC－U管件生产中不易解决的注射缺陷，如注射银纹，烧伤，熔接痕及排气等问题有效解决方法。     

本体法与悬浮法PVC树脂生产工艺的比较及在管件生产中的优势

比较了本体法PVC7型树脂与悬浮法PVC-SG7型的生产工艺,介绍了本体法PVC树脂的质量、塑化性能和加工性能等在管件生产中的优势。     

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.     

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.     

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。     

ICP-MS法测定地球化学样品中As、Cr、Ge、V等18种微量痕量元素的研究

建立了测定地球化学样品中包括As、Cr、Ge、V等18种微量、痕量元素的ICP-MS方法。地化试样用HF-HNO3混酸分解后,以1 1 HNO3溶解干渣。由于制样不使用盐酸,避免了Cl对As、Cr、Ge、V的质谱干扰。用国家一级地球化学标准物质GBW 07309制备溶液优化仪器工作参数,并用于校准。方法测定限(6s)为:0.007~6.4μg/g,精密度(RSD%,n=12)为:29%~9.4%,经过国家一级地球化学标准物质的分析验证,结果与标准值吻合。方法已应用于国土资源调查的试样分析。     

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.     

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.     

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.