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1.
溶胶—凝胶陶瓷薄膜制备工艺技术的研究   总被引:1,自引:0,他引:1  
从溶胶制备和薄膜涂覆工艺两方面对溶胶-凝胶法制备陶瓷薄膜中的工艺技术进行了研究,并指出了溶胶-凝胶技术中存在的一些问题。  相似文献   

2.
溶胶-凝胶法制备掺杂二氧化钛薄膜及其光电性能研究   总被引:1,自引:0,他引:1  
溶胶-凝胶法制备掺杂二氧化钛薄膜及其光电性能研究徐灵戈,黎甜楷(中国科学院感光化学研究所,北京100101)王淑琴,徐维并(中国科学院生态环境研究中心,北京100085)关键词溶胶-凝胶法,掺杂二氧化钛薄膜,光电性能,红外光谱运用溶胶-凝胶法制备玻璃...  相似文献   

3.
溶胶—凝胶陶瓷薄膜制备工艺技术的研究   总被引:8,自引:0,他引:8  
本文从溶胶制备和薄膜涂覆工艺两方面对溶胶-凝胶法制备陶瓷薄膜中的工艺技术进行了研究,并指出了溶胶-凝胶技术中存在的一些问题。  相似文献   

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用溶胶-凝胶合成方法制备固态GPTS-TEOS-LiClO4-TEG体系杂化材料及相应的薄膜,讨论了制备过程中溶液组成对形成固体凝胶的影响和凝胶形成的化学过程,用交流阻抗谱测定了所制备材料的交流阻抗和离子电导率。  相似文献   

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溶胶—凝胶法制备Fe2O3—Mn2O3—SiO2膜   总被引:1,自引:0,他引:1  
用溶胶-凝胶法在浮法玻璃上制备了Fe2O3-Mn2O3-SiO2膜。对膜层的形成特性进行了观察。得出了制备良好膜层的工艺参数。对薄膜的微观结构和光谱特性进行了测定。讨论了薄膜中铁与锰的价态和配位状态。  相似文献   

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采用非水解溶胶-凝胶法通过浸渍溶胶提拉法在陶瓷过滤管上制备氧化铝薄膜,薄膜孔径分布窄,大小为10 nm左右,晶体粒径大小为20 nm左右。通过XRD、TG-DSC、FE-SEM以及傅立叶变换红外光谱仪测试手段,对非水解溶胶-凝胶法制备氧化铝的反应机制进行了研究。研究结果表明非水解溶胶-凝胶法制备氧化铝薄膜的反应机制为:无水三氯化铝和氧供体醇反应生成铝醇盐,铝醇盐在回流过程中发生非水解缩聚反应生成=Al-O-Al=键合并形成溶胶;溶胶在干燥过程中发生进一步的缩聚及溶剂脱除,形成凝胶,凝胶在900℃左右转变为γ-Al_2O_3,γ-Al_2O_3在1100℃左右转变为α-Al_2O_3。  相似文献   

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溶胶-凝胶法制备的Al2O3-ZrO2陶瓷薄膜早期干燥过程的研究   总被引:5,自引:0,他引:5  
采用无机盐先驱体,溶胶-凝胶法制备了Al2O3-ZrO2双组分溶胶,对溶胶膜的早期干燥过程进行了研究,利用扫描电子显微镜观察了不同干燥制度下薄膜的典型形貌,结果表明:Al2O3-ZrO2陶瓷薄膜的早期干燥过程存在着两个恒速干燥期,第1恒速干燥期的干燥速度明显高于第2恒速干燥期,在早期干燥过程中温度的作用非常明显,随着温度的升高,薄膜质量损失率急剧增加,分级干燥制度可以获得光滑平整,无裂纹搞质量薄膜。  相似文献   

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溶胶-凝胶法制备晶粒择优取向铁电薄膜的研究   总被引:1,自引:0,他引:1  
本文综述了用溶胶-凝胶法制备择优取向铁电薄膜的工艺方法、特点和机理的最新研究进展;详细分析溶胶-凝胶法制备择优取向铁电薄膜的影响因素,探讨了晶粒择优取向生长的机理。  相似文献   

9.
溶胶-凝胶法二氧化钛薄膜诱导沉积磷酸钙层   总被引:5,自引:2,他引:5  
碳/碳复合材料作为骨植入材料具有良好的生物力学相容性,但没有生物活性。以玻璃片为基板进行预试,发现溶胶凝胶法制备的锐钛矿型二氧化钛薄膜呵在快速钙化溶液中诱导沉积出由磷酸八钙和羟基磷灰石组成的磷酸钙层,二氧化钛薄膜的微观形貌对快速钙化溶液中磷酸钙沉积物的沉积速度和组成影响不大。在以上预试的基础上,通过溶胶凝胶法制备的二氧化钛薄膜在碳/碳复合材料上复合了生物活性磷酸钙涂层。  相似文献   

10.
综述了制备钛酸钡系薄膜的各种方法,如:溶胶-凝胶法、有机金属化学气相沉积法、射频磁控溅射法、脉冲激光沉积法等,其中主要对溶胶-凝胶法和射频磁控溅射法的制备原理及工艺特点进行了讨论。介绍了钛酸钡薄膜的性质和掺杂后(主要是锶掺杂)对薄膜电性能的影响,对它们的应用现状进行了概括,并对钛酸钡系薄膜的发展趋势做了展望。  相似文献   

11.
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.  相似文献   

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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.  相似文献   

14.
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.  相似文献   

15.
2008~2009年世界塑料工业进展   总被引:4,自引:1,他引:3  
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。  相似文献   

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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.  相似文献   

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