99.99%高纯硅坩埚的研制

根据硅材料的特性以及太阳能、电子工业对硅材料纯度的特殊要求，采用陶瓷凝胶注模成型技术，对原材料、料浆的配制、成型和烧成等过程研制9999％高纯硅坩埚进行了讨论，并将该技术与其它成型方法做了比较。介绍的高纯硅坩埚为提高坩埚法制备高纯硅的质量开辟了一条新途径。     

3000号特大型石墨坩埚研制成功

建行三峡分行宜昌县支行贷款支持的宜昌恒达石墨公司研制成功的 30 0 0号特大型石墨坩埚 ,是国内旋制生产特大型石墨坩埚首创 ,在特种坩埚生产上达到国内先进水平 ,该产品生产工艺技术荣获湖北宜昌市科技创新奖。坩埚是用来熔化金属或其他物质的器皿 ,要求耐高温 ,过去多用白金等耐高温的贵重金属材料制作 ,价格昂贵 ,用石墨制品替代 ,价格要便宜得多。特大型石墨坩埚旋塑工艺技术难度大 ,科技含量高 ,国内无现成经验可借鉴 ,宜昌恒达石墨公司 ,经过反复试验、总结 ,修改原料配方 ,终于攻克了石墨行业共同面临的这一技术难题 ,试制出的第一…     

用重油熔炼铅玻璃

为了发展电视工业,填补祖国电子工业的空白,上海工业玻璃五厂在有关单位协助下,承担了试制飞点扫描管玻璃的任务。由于这种玻璃质量要求高,所以,在试制阶段,曾在矽碳棒高温电炉中用石英坩埚熔炼。但是,由于耗电量大,电力供应不足;坩埚容量小,成品率低;造成生产成本高。对于进一步扩大工业性生产,带来了很大困难。     

直拉单晶炉熔融硅对石英玻璃的腐蚀作用

一、目的意义直拉法制造的大直径硅单晶,被广泛用于集成电路、半导体器件。众所周知,直拉法必须采用石英玻璃坩埚为熔化硅的器皿。而石英坩埚在拉晶过程中常常被腐蚀,直接沾污融熔硅,影响硅单晶的纯度。因此研究高温下融熔硅对石英玻璃的腐蚀作用,对提高硅单晶的质量和纯度有实际的经济意义。二、腐蚀机理融熔硅对石英玻璃的腐蚀作用,主要是     

陕西玻纤总厂加工出低熔点玻璃生产坩埚

陕西玻璃纤维总厂为陕西彩色显像管厂生产的铂铑坩埚于今年2月27日通过省级鉴定.这种坩埚重八公斤,是生产彩色显像管低熔点玻璃的重要设备,过去这种坩埚由日本引进.为了节约外汇,该厂急切需在国内寻找加工生产厂家,陕西玻纤总厂积极配合,横向主动承担了试制工作.通过技术攻关,很快掌握了这种坩埚的加工工艺,加工的坩埚质量稳定,尺寸精度高,厚度均匀,     

特级锦州石油系针状焦试制Φ300mmUHP石墨电极

阐述了用特级锦州石油系针状焦试制Φ300mmUHP石墨电极的全过程,并对压型、焙烧、浸渍和石墨化等工序的抽样编号电极进行直径、长度、质量和体积密度等数据跟踪。结果表明,特级锦州石油系针状焦可以用来生产Φ300mmUHP石墨电极。     

钛硅分子筛的合成与表征

钛硅分子筛在有机物催化氧化及重金属离子吸附等领域发挥着重要作用。分别从影响因素、合成机理以及催化性能等方面对比了水热合成法、同晶取代法和微波辐射法合成钛硅分子筛的差异,列举了在表征钛硅分子筛中钛原子赋存状态、组成和结构等方面所采用的分析手段,并对钛硅分子筛的基础研究与工业应用进行了评述和展望。     

炭/炭复合材料制造硅晶体生长坩埚初探

多晶硅用直拉法(CZ)或磁场直拉法(MCZ)拉制成单晶硅棒。晶体生长炉热场零件中的石墨发热体、坩埚等在机械应力和热应力的综合作用下发生变形或损坏造成失效,更换频繁。选用纯度高的炭纤维制成待制件的多孔坯体,经过增密、纯化处理制成炭／炭复合材料坩埚。试制的两体12″炭／炭复合材料坩埚进行了工业性试验。炭／炭复合材料机械强度高、耐热冲击性能和化学稳定性好,其使用寿命大大高于高纯石墨坩埚。两体的连接止口的氧化侵蚀限制了坩埚的使用寿命。单晶硅设备的大型化、炭／炭复合材料势必成为晶体生长炉热场零件的必选材料。     

电熔透明石英玻璃管的新工艺及设备

目前国内电熔透明石英玻璃管生产厂普遍使用真空电阻炉。其原理是用石墨坩埚为发热体产生高温,使坩埚内的水晶粉全部熔融,然后去除坩埚底部塞子使熔融的水晶流出拉制成管。这种工艺及设备是五十年代从苏联引进的一次成形工艺。 现在工业发达国家对石英玻璃管的圆度、同心度及壁厚等有更高的要求,因此开展了二次成形工艺。该     

矿物及废灰渣合成Na-X分子筛研究进展

多孔Na-X分子筛比表面积大,离子交换能力强,常被应用于废水处理、气体吸附分离等领域,通常由硅、铝无机盐原料合成得到。粉煤灰、煤矸石、高岭土、油页岩、稻壳灰、甘蔗渣等矿物及废渣含有高含量的硅、铝元素,经过预处理可用于合成Na-X分子筛。本文综述了多种天然矿物和工业固体废料的组成及合成Na-X分子筛的最新研究进展,讨论了不同矿物和固体废料合成Na-X的活化工艺、晶化动力学及机理,重点分析了合成条件对矿物和固体废料合成Na-X的影响,包括硅铝比、晶化温度、晶化时间、阴阳离子、水硅比、碱灰比、超声条件和有机添加剂的影响。     

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。     

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.     

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.