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以丙二酸二乙酯为起始原料,经选择性皂化、酸化、氯化、环合和酰胺化反应合成了2-[5-(3-羟基苯甲酰氨基)-1,3,4-噻二唑]基乙酸乙酯(1),总收率37.2%,其结构经1H NMR,13C NMR,IR和LC-MS(ESI)确证。采用正交实验法[L_9(3~4)]优化了酰胺化反应的条件。结果表明:在最优反应条件{n[2-(5-氨基-[1,3,4]-噻二唑)基乙酸乙酯]∶n(三乙胺)∶n(间羟基苯甲酰氯)=1∶2∶3,于20℃反应8 h}下,1收率75.5%。 相似文献
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Si wafers with a 220 nm top oxide layer were sequentially implanted at room temperature with 40 keV He and 35 keV H ions at a fluence of 5×1016 /cm2 and 1×1016 /cm2 , respectively. Techniques of scanning electron microscopy, atomic force microscopy and cross-sectional transmission electron microscopy (XTEM) were used to characterize the thermal evolution of surface damage as well as defect microstructures. Surface blisters as well as the localized exfoliation (~0.42 μm in depth) have been observed for samples annealed at temperatures of 500℃ and above. XTEM observations reveal a variety of defect microstructures, including cavities, platelets, nanometer or micrometer sized cracks and dislocations. The platelets and cracks are mainly distributed at a depth of about 0.42 μm parallel to the sample surface, which are responsible for the occurrence of the observed surface features. The relationship between surface damage and defect microstructures is described in detail. 相似文献
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以溴酰化β-环糊精(β-CD-Br)为引发剂,通过原子转移自由基聚合(ATRP)制备了以β-CD为核的温敏星形聚N-异丙基丙烯酰胺(β-CD-PNIPAM)。以具有氧化还原性质的二茂铁-聚乙二醇(Fc-m PEG)为客体分子,通过环糊精和二茂铁的主-客体识别作用自组装得到温度/氧化还原双响应超分子复合胶束(β-CD-PNIPAM/Fc-mPEG)。结果表明,超分子复合胶束具有规则的球形结构,直径约为100nm左右,具有可逆的温度和氧化还原刺激响应性。当升高温度至胶束的LCST以上且加入不同浓度的H2O2时,胶束结构破坏,实现药物的可控释放。这种具有良好温度和氧化还原双响应特性的超分子胶束是抗癌药物的良好载体。 相似文献
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采用溶胶凝胶方法和水热法制备了水溶性荧光氧化锌量子点(Zn O-QDs)和碳量子点(C-QDs),其量子效率分别达到38%和61%。基于所合成的Zn O-QDs和C-QDs制备了氧化锌和碳量子点复合物(Zn O/CQDs),并分别对其发光特性进行了研究。透射电镜(TEM)图像表明,所合成的Zn O-QDs和碳量子点尺寸分布在3~6 nm之间,分散均匀。光致发光光谱表明,Zn O-QDs和碳量子点的发光峰中心分别位于540 nm和450 nm,两者发光峰的最佳激发波长为370 nm和350 nm。通过调整Zn O-QDs和C-QDs的体积比,所制备的Zn O/C-QDs能够实现荧光光谱的连续可调,并产生了白色荧光。 相似文献
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室温下将130 keV,5x1014 cm-2 B离子和55 keV,1x1016 cm-2 H离子单独或顺次注入到单晶Si中,采用横截面试样透射电子显微镜(XTEM)和慢正电子湮没技术(SPAT) 研究了离子注入引起的微观缺陷的产生及其热演变。XTEM观测结果显示,B 和H 离子顺次注入到单晶Si 可有效减少(111) 取向的H板层缺陷,并促进了(100) 取向的H板层缺陷的择优生长。SPAT 观测结果显示,在顺次注入的样品中,B 离子平均射程处保留了大量的空位型缺陷。以上结果表明,B离子本身及B 离子注入所产生的空位型缺陷对板层缺陷的生长起到了促进作用。Abstract:Cz n-type Si (100) wafers were singly or sequentially implanted at room temperature with 130 keV B ions at a fluence of 5x1014 cm-2 and 55 keV H ions at a fluence of 1x1016 cm-2. The implantation-induced defects were investigated in detail by using cross-sectional transmission electron microscopy (XTEM) and slow positron annihilation technique (SPAT). XTEM results clearly show that sequential implantation of B and H ions into Si could eliminate the (111) platelets and promote growth of (100) platelets during annealing. SPATmeasurements demonstrate that in B and H sequentially implanted and annealed Si, more vacancy-type defects could remain in sample region around the range of B ions. These results indicat e that the promotion effect shouldbe attributed to the role of both B and B implanted induced vacancy-type defects. 相似文献
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特丁津分子印迹整体萃取棒的研制及其萃取性能 总被引:3,自引:3,他引:0
以特丁津为模板分子,甲基丙烯酸为功能单体,三羟甲基丙烷三甲基丙烯酸酯为交联剂,甲苯为致孔剂,在75 ℃下封管聚合反应24 h后,以HF溶液腐蚀除去玻璃毛细管,制备得到分子印迹整体萃取棒,优化了聚合配方和合成条件.采用扫描电镜表征了萃取棒表面形貌,结果表明:萃取棒表面呈疏松、多孔的结构.研究了特丁津分子印迹整体萃取棒作为三嗪类除草剂样品前处理分离介质的萃取条件和萃取性能.采用甲苯为萃取剂,萃取60 min后以150 μL甲醇解吸.与不加模板分子的整体萃取棒相比,分子印迹整体萃取棒对模板分子特丁津及其结构类似物西玛津、西草净、莠去津、莠灭净、扑灭津及特丁净表现出选择性识别能力,富集率分别提高到1.5~8.1倍,对氯三嗪的萃取选择性优于硫三嗪. 相似文献
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Si wafers with a 220 nm top oxide layer were sequentially implanted at room temperature with 40 keV He and 35 keV H ions at fluence of 5× 1016/cm2 and 1× 1016/cm2, respectively. Techniques of scanning electron microscopy, atomic force microscopy and cross-sectional transmission electron microscopy (XTEM) were used to characterize the thermal evolution of surface damage as well as defect microstructures. Surface blisters as well as the localized exfoliation (~ 0.42 μm in depth) have been observed for samples annealed at temperatures of 500 ℃ and above. XTEM observations reveal a variety of defect microstructures, including cavities, platelets, nanometer or micrometer sized cracks and dislocations. The platelets and cracks are mainly distributed at the depth of about 0.42 μm parallel to the sample surface, which are responsible for the occurrence of the observed surface features. The relations between surface damage and defect microstructures are described in detail. 相似文献
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