Sol—Gel法制备PbTiO3超细粉末的实验研究

本文以钛酸丁酯和醋酸铅作为原料，利用溶胶─凝胶方法制备出了纳米级的PbTiO3超细粉末，醋酸铅的结晶水通过直接加热的方法除去。并用正交试验的方法确定了PbTiO3超细粉末的制备条件。在该实验条件下获得的凝胶，经80℃干燥后，在400℃下热处理2小时可以得到完全结晶化的纳米级PbTiO3超细粉末。通过测试分析表明，PbTiO3超细粉末的颗粒为多面体形，无明显硬团聚，粒径分布在30－80nm的范围内，其平均粒径为60nm，而其纯度达到含PbTiO399．67wt％，杂质主要是游离的PbO。     

利用表面形成Si_2N_2O层提高Si_3N_4陶瓷材料抗氧化性能

根据对Ｓｉ－Ｎ－Ｏ系统相图的分析，首次在Ｓｉ３Ｎ４陶瓷材料表面形成Ｓｉ２Ｎ２Ｏ抗氧化层。其方法是利用Ｓｏｌ－Ｇｅｌ在Ｓｉ３Ｎ４陶瓷的表面涂上一层ＳｉＯ２（其中含有１０％的Ａｉ２Ｏ３）涂层后，在Ｎ２气氛中，并有Ｓｉ３Ｎ４粉末和ＳｉＯ２粉末存在的条件下，于１２７３～１６７３Ｋ的温度下进行热处理。用ＸＲＤ和ＸＰＳ分析验证了Ｓｉ２Ｎ２Ｏ（和／或Ｏ’－Ｓｉａｌｏｎ）层的存在。由于形成了Ｓｉ２Ｎ２Ｏ（和／或Ｏ’－Ｓｉａｌｏｎ）层，Ｓｉ３Ｎ４陶瓷材料在１５７３Ｋ的温度下氧化１００ｈ后，氧化增量从原来的０．４２ｍｇ／ｃｍ２降低到０．２４ｍｇ／ｃｍ２。     

溶胶—凝胶法合成了BaAl2Si2O8超细粉末的研究

以Ｂａ（ＯＨ）２．８Ｈ２Ｏ，Ａｌ（ＮＯ３）３．９Ｈ２Ｏ，ＴＥＯＳ为原料，采用溶胶－凝胶法制备ＢａＯ－Ａｌ２Ｏ３－ＳｉＯ２三元系粉末，研究了不同因素对生成稳定溶胶和胶化时间的影响，用ＴＧ－ＤＴＡ，ＸＲＤ研究了溶胶－凝胶的热处理过程，用ＴＥＭ观察了粉体的粒径。     

纳米Si3N4-SiC(Y2O3)复合粉末的氨解溶胶-凝胶法合成

以硅溶胶、尿素和碳黑为原料,经氨解溶胶－凝胶、碳热还原法合成了纳米Ｓｉ３ｎ４－ＳｉＣ复合粉末。通过在硅溶胶中引入Ｙ（ＮＯ３）３,合成了Ｓｉ３ｎ４－ＳｉＣ－Ｙ２Ｏ３超细复合粉末,Ｙ２Ｏ３的加入有助于降低Ｓｉ３Ｎ４－ＳｉＣ的合成温度。采用ＸＰＳ和ＸＲＤ分析复合粉末中Ｙ的存在状态表明：一部分Ｙ固溶在Ｓｉ３Ｎ４－ＳｉＣ中,加有一部分以Ｙ２Ｏ３形式存在,Ｓｉ３Ｎ４－ＳｉＣ－Ｙ２Ｏ３复合粉末的烧结性能良好。     

PZTS系凝胶玻璃及玻璃陶瓷的结构研究

采用溶胶凝胶工艺在低温下合成均匀透明的ＰＺＴＳ新型多组元凝胶玻璃，并在凝胶玻璃中成功地析出ＰｂＴｉＯ３，Ｐｂ（Ｚｒ，Ｔｉ）Ｏ３纳米微晶。利用ＩＲ谱分析了凝胶玻璃中Ｓｉ－Ｏ－Ｓｉ，Ｓｉ－Ｏ－Ｔｉ等化学键在成胶过程中的形成以及在热处理过程中的变化，根据Ｋｉｓｓｉｎｇｅｒ原理估算了ＰＴＳ凝胶玻璃的析晶活化能。借助ＸＲＤ较系统地研究了凝胶玻璃在高温下的结晶结构。探讨了在ＰＺＳ、ＰＺＴＳ体系中ＺｒＯ２和Ｓｉ     

Sm,Gd共同掺杂的CeO2基电解质性能研究

用Ｓｍ２Ｏ３和Ｇｄ２Ｏ３共同掺杂ＣｅＯ２基电解质组分（ＣｅＯ２）０．９０（Ｓｍ２Ｏ３）０．０５（Ｇｄ２Ｏ３）０．０５）,可以在较低的温度（１４００－１４５０℃）烧结并较高电导率,８００℃时电导率约为７Ｓ．ｍ＾－１。     

溶胶—凝胶工艺合成PbTiO3—SiO2微晶玻璃及其特性研究

利用醋酸铅、钛酸四丁酯和正硅酸乙为主要原料，采用溶胶－凝胶工艺低温合成了ＰｂＴｉＯ３－ＳｉＯ２微晶玻璃，运用ＤＴＡ，ＸＲＤ和ＩＲ等手段对样品的结构和晶化规律进行了研究，紫外吸收光谱研究发现样品中的纳米微晶表面出明显的量子尺寸效应，最后四波混频方法对样品的光学性能进行了研究。     

正丁醇钛—乙酸钡水解法合成BaTiO3粉体的研究

本文着重研究了Ｔｉ（Ｏ＾ｎＢａ）４－Ｂａ（ＤＡｃ）２水解法合成高纯超细ＢａＴｉＯ３粉体的制备工艺。借助ＴＧＤＴＡ，ＸＲＤ，ＴＥＭ，ＳＥＭ，ＳＡＸＳ和ＩＣＰ－ＡＥＳ等分析手段，研究了ＰＨ值，Ｂａ／Ｔｉ比和（Ｂａ／Ｔｉ）比，反应温度，浸泡处理等对ＢａＴｉＯ２粉体性能的影响，采用本工艺方法合成的ＢａＴｉＯ３粉体，纯度达９９．８０ｗｔ％，比表面积为６８ｍ＾２／ｇ，一次粒子平均粒径４６．７ｎｍ，二次粒子粒径     

SOL—GEL法制备新型复合磁粉

本文产次报导用ＳＯＬ－ＧＥＬ法制备钡铁本泡覆纺锤形α－Ｆｅ２ｏ３粉末。ＢＦ－α－Ｆｅ２Ｏ３可以在３８０℃，还原气氛下制成包钡铁氧体的γ－Ｆｅ２Ｏ３复合磁粉。     

纳米级ZrO2（Y2O3）／Al2O3粉末的制备及其烧结性能

本文采用化学共沉淀凝胶法制备了２ｍｏｌ％Ｙ２Ｏ３－ＺｒＯ２－２０ｗｔ％Ａｌ２Ｏ３纳米级超细复合的陶瓷粉末，在常压下对该粉末进行了不同温度下的烧结试验，利用ＸＲＤ分析了粉末的相组成；用ＸＲＤ－ＢＬ法计算了粉晶尺寸，用ＴＥＭ研究了粉末的形貌，大小及其分布，用Ａｒｃｈｉｍｅｄｅｓ法测定了烧结体的体积密度，用ＳＥＭ观察测定了烧结体的显微结构，结果表明，该法制备的粉末尺寸分布范围窄，分散性好，粉体烧结活性高     

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.     

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.     

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。     

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。