尖晶石型高效红外辐射陶瓷的制备和研究

本文设计了六个尖晶石型铁氧体的配方，1100℃-1280℃于空气中烧成，经XRD测试分析证明，生成了CoFe2O4,NiFe2O4等反尖晶石型结构铁氧体和MnFe2O4,CuFe2O4,CuMn2O4等混合尖晶石型结构铁氧体。经测定，六个配方铁氧体陶瓷的全波段辐射分率分别为0．83、0．87、0．81，0．86，达到了较高的水平，是优良的高效红外辐射陶瓷。     

固相合成CuFe2O4及其气敏性能

以无机盐为原料,采用低热固相化学反应法合成了尖晶石型复合氧化物CuFe2O4的前驱体,通过不同温度煅烧,最后得到尖晶石复合氧化物CuFe2O4.用X射线衍射和透射电镜对合成产物进行了表征.结果表明:煅烧温度对尖晶石结构的形成有较明显的影响,当温度达到800℃时固相反应完全.合成材料的尺寸约为50 nm,但由于铁酸盐有磁性而存在轻微团聚.将样品制成旁热式气敏元件,气敏测试结果表明:元件在较低的工作温度时,对H2S气体具有较高的灵敏度和选择性,对体积分数为25×10-6的H2S气体的灵敏度接近9.     

尖晶石型铁氧体AgxZn1-xFe2O4(x=0.1～0.5)的制备及光催化性能的研究

采用溶胶-凝胶法制备了尖晶石型铁氧体AgxZn1-xFe2O4.利用XRD,SEM对纳米颗粒的结构、形貌进行了表征.结果表明,所合成的样品为尖晶石型铁氧体,形貌呈块状,粒径不均匀.通过对甲基橙的降解情况对其光催化活性进行了研究.结果表明,经过Ag+少量掺杂的AgZn1-xFe2O4样品,光催化活性提高.     

尖晶石型铁氧体Cu_xZn_(1-x)Fe_2O_4(x=0~0.5)的制备及光催化性能的研究

采用溶胶-凝胶法制备了尖晶石型铁氧体Cu x Zn1-x Fe2O4。利用XRD,SEM对纳米颗粒的结构、形貌进行了表征。结果表明,所合成的样品为尖晶石型铁氧体,形貌呈规则颗粒,随着Cu掺杂量的增加可使样品粒径减小。通过对甲基橙的降解情况对其光催化活性进行了研究。结果表明,经过Cu2+掺杂可加快甲基橙降解速率,少量掺杂的Cu x Zn1-x Fe2O4样品,光催化活性可以提高。     

La掺杂Ni0.5Zn0.5Fe2O4铁氧体的制备与微波吸收性能

采用高分子凝胶法制备了Ni0.5Zn0.5LaxFe2-xO4 (x=0, 0.05, 0.1)铁氧体,采用XRD, TEM和HP8510网络分析仪对其结构、形貌、电磁和微波吸收性能进行了研究. 结果表明,当煅烧温度为600℃时,立方晶系尖晶石结构的Ni0.5Zn0.5La0.05Fe1.95O4相初步形成,La在尖晶石结构中固溶量有限. 与Ni0.5Zn0.5Fe2O4铁氧体相比,掺杂La的Ni-Zn铁氧体的tandm值降低,tande值升高. 与Ni0.5Zn0.5Fe2O4铁氧体相比,x=0.1样品的吸波性能降低,而x=0.05样品的吸波性能提高,其电磁波反射率小于-10 dB的频宽可达2.7 GHz,最小反射率为-15.6 dB.     

La掺杂Ni0.5Zn0.5FeO4铁氧体的制备与微波吸收性能

采用高分子凝胶法制各了Ni0.5Zn0.5LaxFe2-xO4(x=0,0.05,0.1)铁氧体,采用XRD,TEM和HP8510网络分析仪对其结构、形貌、电磁和微波吸收性能进行了研究.结果表明,当煅烧温度为600℃时,立方晶系尖晶石结构的Ni0.5Zn0.5La0.05Fe1.95O4相初步形成,La在尖晶石结构中固溶量有限.与Ni0.5Zn0.5Fe2O4铁氧体相比,掺杂La的Ni-Zn铁氧体的tanδm值降低,tanδε滥升高.与Ni0.5Zn0.5Fe2O4铁氧体相比,x=0.1样品的吸波性能降低,而x=0.05样品的吸波性能提高,其电磁波反射率小于-10 dB的频宽可达2.7 GHz,最小反射率为-15.6 dB.     

Na~+掺杂对尖晶石型Co_(1-x)Na_xFe_2O_4的结构及光催化性能的影响

采用溶胶-凝胶法制备了尖晶石型铁氧体Co1-xNaxFe2O4的系列样品,通用XRD,SEM对颗粒的结构、形貌进行了分析。结果表明,所合成的样品均为尖晶石型铁氧体;未掺杂样品CoFe2O4的形貌呈立方颗粒状,粒径均匀,边长约为1μm,掺杂后的样品Co0.8Na0.2Fe2O4颗粒为圆球状,尺寸大约在100~200nm,且有明显团聚的现象。通过对亚甲基蓝的降解情况对其光催化活性进行了研究。结果表明,经过A位Na+掺杂的CoFe2-xCrxO4样品,光催化活性明显提高。     

纳米晶CO1-xNixFe2O4铁氧体的制备及Ni2+对其磁性能的影响

采用喷射-化学共沉淀法制备了纳米晶Co1-xNixFe2O4(0≤x≤1)铁氧体粉料.通过热重-差热分析、X射线衍射、电子显微镜和比表面积测试手段分析了铁氧体粉体的微观结构和形貌,采用振动样品磁强计对其磁性能进行了测量.结果表明:喷射-共沉淀法制备的Co1-xNixFe2O4铁氧体纳米粉料颗粒细小均匀、形状完整.X射线衍射分析证明:纳米晶Co1-xNixFe2O4铁氧体为尖晶石型固溶体.600℃下煅烧1.5 h,样品晶粒尺寸约为40 nm左右,平均颗粒尺寸小于100 nm.室温下,样品比饱和磁化强度和矫顽力随着Ni 2离子含量增加而减小.     

水热法制备NiFe2O4-BaTiO3复合材料及其电-磁性能

本文利用水热法以铁酸镍和钛酸钡为原料,制备了具有尖晶石结构的铁酸镍(NiFe2O4)和钙钛矿结构的钛酸钡(BaTiO3)复合材料,利用X射线衍射(XRD)和扫描电镜(SEM)对样品的物相和形貌进行了分析。研究了复合样品的介电常数和磁导率随频率和温度的变化。结果表明:复合样品中的钛酸钡在烧结后由四方相转变成六角结构;生成六角结构的钛酸钡颗粒和类球状铁氧体颗粒;介电常数和磁导率随铁氧体含量的增加逐渐增大,复合陶瓷的介电居里温度随铁氧体含量的增加向低温方向移动,磁性居里温度随铁氧体含量的增多向高温方向移动,逐渐接近铁氧体的居里温度。     

水热法制备尖晶石型镍铁氧体

采用水热法制备尖晶石型镍铁氧体,研究了反应温度、反应时间对产品的影响,在p H=9,230℃,4 h时制得的Ni Fe2O4的晶形最好,XRD衍射峰最强,形貌最佳和比饱和磁化强度最大。     

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.     

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。     

Inorganic/organic nanocomposite coatings: The next step in coating performance

Inorganic/organic hybrid materials have considerable promise and are beginning to become a major area of research for many coating usages, including abrasion and corrosion resistance. Our primary approach is to prepare the inorganic phase in situ within the film formation process of the organic phase. The inorganic phase is introduced via sol-gel chemistry into a thermosetting organic phase. By this method, the size, periodicity, spatial positioning, and density of the inorganic phase can be controlled. An important aspect of the inorganic/organic hybrid materials is the coupling agent. The initial task of the coupling agent is to provide uniform mixing of the oligomeric organic phase with the sol-gel precursors, which are otherwise immiscible. UV-curable inorganic/organic hybrid systems have the advantages of a rapid cure and the ability to be used on heat sensitive substrates such as molded plastics. Also, it is possible to have better control of the growth of the inorganic phase using UV curing. It is our ultimate goal to completely separate the curing of inorganic and organic phases to gain complete control over the morphology, and hence optimization of “all” the coating properties. Thus far, it has been found that concomitant UV curing of the inorganic and organic phases using titanium sol-gel precursors afforded nanocomposite coatings which completely block the substrate from UV light while maintaining a transparent to visible light. Also, it has been found that the morphology of the inorganic phase is highly dependent on the concentration and reactivity of the coupling agent. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004, in Chicago, IL.