铅基织构压电陶瓷研究进展

铅基织构压电陶瓷由于具有优异的机电耦合性能、高性价比、组分均匀、形状可控等优点,成为了近些年学术界和工业界所关注的热点材料,也被认为是众多压电器件更新换代的关键材料.本工作介绍了铅基织构压电陶瓷的设计原理和制备技术,分析了其相比于单晶及传统多晶陶瓷材料的特点和优势;其次,综述了铅基织构压电陶瓷制备方面的最新研究进展;最...     

可加工陶瓷材料的机械加工技术

介绍云母玻璃陶瓷、氧化物陶瓷和非氧化物陶瓷3类可加工陶瓷材料的显微结构特性与材料可加工性的关系，层片状结构与弱界面使陶瓷材料具备可加工性。分析了可加工陶瓷材料机械加工过程中的特性；适宜的加工工艺参数、低加工损伤及材料的沿晶界断裂模式。结合金属材料的可加工性研究，讨论了适于陶瓷材料可加工性评价的研究方法。     

稀土氧化物在氮化硅陶瓷中应用的研究进展

简要论述了稀土氧化物在氮化硅陶瓷材料中的应用研究概况,介绍了单一稀土氧化物以及复合掺杂稀土氧化物在氮化硅陶瓷材料中的应用进展,并比较了它们对氮化硅陶瓷材料性能的影响;最后对稀土氧化物在氮化硅陶瓷材料中的应用前景作了简单分析和展望.     

铝铬陶瓷材料抗熔渣腐蚀性的提高

在以前的研究中，发现熔渣中陶瓷材料的腐蚀主要依赖于渣的粘度和陶瓷与熔渣之间的碱性缝隙。本研究是在腐蚀测试的基础上，推荐用渣的粘度和碱性缝隙函数方程来预测陶瓷材料在熔渣中的腐蚀率。Cr2O3-Al2O3陶瓷材料是放在SiO2-CaO-B2O3碱性熔渣中进行测试的。     

MAX相陶瓷强化方式及机理研究进展

MAX相陶瓷兼具金属和陶瓷的优良性能,在航空航天、高铁、核工业等许多高新技术领域拥有巨大的应用潜力。但是,MAX相的强度和硬度偏低,这限制了其在实际工程中的应用。本文总结了MAX相陶瓷材料的强化方式及机理,重点介绍了固溶强化、第二相颗粒强化和织构强化等强化方式对MAX相陶瓷力学性能的影响。最后,展望了MAX相材料强化的研究前景。为该材料在实际工程中应用提供了重要的参考价值。     

分析化学在陶瓷材料检测方面的应用

本文介绍了分析化学的方法和种类，阐述了分析化学在陶瓷材料检测中的作用。分别介绍了XRD、激光粒度、化学滴定三种分析方法对氧化锆陶瓷材料方面检测的应用，指出了分析化学在陶瓷材料检测中的重要性。     

利用外加SiC改善Si3N4陶瓷材料的抗氧化性能

本文研究了Si3N4-Al2O3-Y2O3系陶瓷材料的氧化行为。实验结果表明：Si3N4陶瓷材料在空气中的氧化行为服从抛物线规律，同时在Si3N4陶瓷中加入抗氧化能力比Si3N4更强的SiC颗粒，可以有效地提高Si3N4陶瓷材料的抗氧化性能，当加入的SiC量为15wt%时，可使Si3N4陶瓷材料的抗氧化能力提高一倍左右。     

非规则V形表面织构化机械端面密封性能研究

针对一种新型非规则V形表面织构化机械密封端面，建立了界面液膜的润滑模型，采用有限单元方法求解雷诺方程，研究了表面织构开孔面积比、深度比、特征数和密封介质压力对端面密封的承载力、泄漏率、摩擦因数和液膜刚度等密封性能参数的影响规律，并对经典三角形织构和圆形织构化端面密封进行了对比分析。结果表明：端面新型非规则V形织构具有收集和汇聚液膜的作用，增强了动压效应；织构开孔面积比、深度比、特征数和密封介质压力的变化对V形与三角形表面织构的密封性能影响较大，而对圆形织构表面的密封性能影响不明显；在研究几何和工况参数范围内，这种新型V形表面织构的机械密封性能相对较优，其承载力、摩擦因数与液膜刚度均略优于三角形织构，远优于圆形织构，研究结果可为织构化端面密封的设计开发提供支持。     

陶瓷材料增韧研究进展

陶瓷材料的脆性是制约其更广泛应用的主要因素，增韧是陶瓷材料领域科学家和工程技术人员孜孜以求的目标。本文简要介绍了陶瓷材料增韧的主要方法及其机理，分析了陶瓷材料增韧的研究现状，最后讨论了陶瓷材料增韧的发展方向。     

陶瓷材料在酸碱中的抗化学侵蚀性

研究了陶瓷材料在酸碱中的抗化学侵蚀能力及其测定方法。确定了各种不同陶瓷材料在酸碱中抗化学侵蚀性的数据值。有可能根据预先规定的抗酸碱侵蚀性数值来研究陶瓷材料的抗化学侵蚀性。     

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.     

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.     

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。     

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.