气-固相反应制备超细氧化锡粉末研究

以五水合四氯化锡和碳酸氢铵为原料，用气-固相反应制备了纳米二氧化锡，并用X-射线衍射(XRD)和透射电镜(TEM)对粉末进行了表征。气-固相反应制备纳米二氧化锡的最佳工艺为：五水合四氯化锡和碳酸氢铵的物质的量比为1：8，焙烧温度240℃，焙烧时间24h，热处理温度500℃，热处理时间0．5h。在最佳工艺条件下，二氧化锡的粒径约为5～10nm，产率达84．3％。     

真空法合成甲基硫醇锡研究

研究了以巯基乙酸异辛酯和甲基氯化锡为原料，在真空下直接合成甲基硫醇锡的工艺．该法操作简单、成本低，该工艺分3个阶段分别控制压强、温度和时间，其最佳反应条件为，第一阶段2．667kPa，70℃反应2h；第二阶段1．333kPa，80℃反应2h；第三阶段0．667kPa，80℃反应1h。合成的产品质量稳定，并能有效降低污染物的排放量，甲基氯化锡的转化率在99％以上。     

液相氧化-喷雾干燥法制备高纯超细二氧化锡颗粒

为了减少反应中氮氧化物(NO_x)排放对环境造成的影响，提高二氧化锡产品纯度、减小粒径，以金属锡粒和稀硝酸为原料，采用液相硝酸氧化法与喷雾干燥工艺结合制备高纯超细二氧化锡颗粒。考察锡源类型、硝酸浓度及滴加速度、反应温度及煅烧温度等参数对产物的影响，并利用X射线衍射仪、电感耦合等离子体发射光谱仪、扫描电子显微镜、激光粒度仪、比表面积分析仪等对所制备的偏锡酸(H₂SnO₃)和二氧化锡进行结构和性能表征。结果表明：以锡粒为锡源、硝酸质量分数为25%、滴加速度为30 m L/min、反应温度为80℃，经喷雾干燥工艺处理，再经950℃煅烧，最终制得纯度为99.997%、D₅₀为1.15μm、D₉₀为2.44μm、比表面积为3.86 m²/g的二氧化锡，该产品在屏幕显示技术领域有重要应用，可用于制备氧化铟锡粉体材料(ITO)。     

一种白色导电粉的制备研究

利用TiO2、硅酸钠为原料，在TiO2表面包硅，再以四氯化锡、三氯化锑为原料，用非均相共沉淀法制备梯掺杂二氧化锡的白色导电粉。并用透射电镜（TEM），激光粒度仪（LPA），白度仪等测试手段分析了主要工艺参数pH值、反应时间、团聚、煅烧条件对最终粉体导电性与白度的影响规律。     

二氧化锡粉体材料的制备及表征

以二水合二氯化锡为主要原料,用微波加热法制备二氧化锡粉体.用粒度仪、比表面积仪、扫描电镜、X射线衍射仪等对所得粉体进行表征.结果表明:微波加热可使原料反应生成粉体颗粒,其反应物浓度、溶液pH、微波加热功率及反应时间都对粒径产生影响.在二水合二氯化锡用量0.84 g、微波加热功率400 W、溶液pH为1.9～3.0、反应时间20 min、反应物浓度为3.5 mmol/L时,可以制备出二氧化锡粉体.从电镜照片可以看出,可以制备出部分的纳米级二氧化锡粉体.     

直接法合成甲基氯化锡的工艺研究

以锡箔、一氯甲烷、四氯化锡为原料,以铵盐为催化剂直接合成甲基氯化锡。考察了压力、温度、反应时间、催化剂种类及用量对反应的影响,并用高效液相色谱分析了产品组分的质量分布。结果表明,直接法合成甲基氯化锡的最佳工艺条件为：压力1～2MPa、温度200℃、反应时间8h,催化剂用量为锡箔投入量的3．5％,此时产品收率达83．5％。     

二氧化锡光催化剂在环境净化技术光催化降解甲基橙的应用研究

基于水热法使用四氯化锡和氢氧化钠作为原材料,在220℃合成了二氧化锡纳米晶。二氧化锡纳米晶为四方相,平均晶粒尺寸约为29 nm。通过傅里叶红外光谱分析表明,在低波数段观察到了Sn-O伸缩振动峰。以甲基橙为降解染料,二氧化锡纳米晶在紫外光照下降解率可达82%左右。     

Sb:SnO2纳米粉末材料的制备研究

以四氯化锡、三氯化锑、氨水为原料，采用胶溶法制得纳米级Sb：SnO2粉末．用X射线衍射和透射电镜对产品进行分析。考察了影响产品性能的各种因素．获得较佳的工艺条件。     

无水四氯化锡制备的研究

本文介绍了无水四氯化锡经发烟硫酸或五氧化二磷等作用，制得无水四氯化锡的方法。该法原料易得、操作便简，适于实验室的制备。无水四氯化铝是合成有机锡化合物的基本原料，一般由金属锡与氯气直接反应制得。由于它极易与水作用生成锡酸（水含氧化锡），在空气中即可潮解[1]，因此难于运输和保存，造成该试剂的缺乏。而其水合物却是稳定的，故可用来制备无水四氯化锡。已报道了将锡酸的浓盐酸溶液经蒸至145t浓缩、再以万％的发烟硫酸处理得到无水四氯化锡，收率为94％PJ。笔者用易得的五水合四氯化锡晶体为原料，分别经20％发烟硫酸、50％发烟硫酸及五氧化二磷的浓硫酸溶液于75-80℃脱水，以91％、91％、75％的收率制得无水四氯化锡。     

四氯化锡催化合成富马酸二甲酯

以四氯化锡为催化剂,浓磷酸、硫脲、溴化钠为辅助催化剂组成混合物催化剂。用马来酸酐和甲醇为原料"一锅法"合成富马酸二甲酯。酯化反应的优惠工艺条件:四氯化锡1 0g,浓磷酸2 0ml,硫脲1 0g,溴化钠1 0g,马来酸酐与甲醇的质量比为1∶7,回流反应时间2 5h,收率达82 5%。该法以四氯化锡取代传统液体酸浓硫酸和浓盐酸,具有反应时间短,收率高,对设备无腐蚀性,对环境污染小的特点。     

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。