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以锐钛矿TiO2为起始原料,通过水热法制备了钛酸盐纳米棒,对合成不同长度和宽度的钛酸盐纳米棒的影响和控制条件进行了研究。用X射线衍射(XRD)和扫描电子显微镜(SEM)对纳米棒的形貌和结构进行了表征。结果表明水热温度和处理时间能对纳米棒的形貌和结构进行有效的控制,得到理想的钛酸盐的结构。在更高的温度下(200 ℃),钛酸盐纳米管将更快的转化为纳米棒,而随着处理时间的延长,其形貌结构发生有规律的变化。在96 h处理时间后纳米棒束的宽度为50 nm到1 μm,长度可以达到几十微米。对后处理中酸洗对产物的形貌和晶体结构的影响也进行了对比研究,发现在酸洗之前钛酸盐纳米棒结构就已经形成,但是酸洗能使产物的晶体结构产生变化,同时使纳米棒的表面形貌更加光滑规整。最后对比研究原料和产物的紫外-可见吸收光谱,发现纳米管/棒在250至350 nm处有宽带隙吸收。 相似文献
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不同形貌ZnSe的制备及光电化学性能 总被引:2,自引:1,他引:1
采用水热法制备了ZnSe纳米棒和微球, 用XRD, TGA-DTA和SEM等技术对其进行了表征, 提出了解释ZnSe微球的形成新机理. 研究结果表明, 纳米棒直径为50~100 nm, 棒长约为200~300 nm, ZnSe微球直径为3~10 μm.; 纳米棒在反应温度为240 ℃时具有闪锌矿和纤维锌矿型混晶结构, 微球在反应温度为210 ℃时具有闪锌矿结构; 将ZnSe纳米棒和微球均匀地涂在导电玻璃的导电面上, 于380 ℃煅烧40 min后制成膜电极, 并进行了光电化学研究, 纳米棒膜结构电极最高单色光的光电转换效率(IPCE)可达到9.09%. 相似文献
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以硝酸锌为锌源,乙醇胺为矿化剂,水为溶剂,微波加热20 min,合成了由微米棒自组装而成的ZnO微米"花" (1),其结构和形貌经X-射线衍射、场扫描电子显微镜和透射电子显微镜表征.结果表明,1由六棱柱形的微米棒自组装而成,微米棒长度1 μm~1.5 μm,直径300 nm~500 nm. 相似文献
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用溶剂热法合成了作为一种新型锂离子电池负极材料的FeSb2纳米棒. 高分辨透射电镜(HRTEM)观察表明, FeSb2纳米棒的直径为20~40 nm, 长度为0.2~1.0 μm. 恒流充放电测试和循环伏安测试显示, FeSb2纳米棒首次可逆容量达到543 mAh•g−1, 经过10次循环后, 可逆容量保持在353 mAh•g−1. 虽然首次库仑效率仅为64%, 但仍明显优于FeSb2纳米颗粒, 并在10次循环后基本稳定在90%. FeSb2纳米棒在循环过程中仍可能发生粉化和破裂, 导致电极逐渐失效. 相似文献
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以Ti-O-Ti油酸偶合体作为结构引导生长剂,
采用溶剂热技术成功地制备了单晶无水硫酸钙纳米管, 并通过XRD、 X射线能谱(EDX)、
TEM、选区电子衍射(CBED)对CaSO4纳米管进行了表征. 其晶格常数与JCPDS标准卡单斜相CaSO4晶体数值一致,
属P(3)m1(164)空间群. 纳米管呈均匀的直管形, 直径约为30 nm, 内径约为10
nm, 长度达到3.0 μm. 并对硫酸钙纳米管的形成机理进行了浅析,
提出了非片状结构的离子晶体,
通过结构引导生长剂诱导生长成为片状结构,
在溶剂热条件下弯曲、旋转、卷拢形成纳米管的新方法. 相似文献
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以十六烷基三甲基溴化铵(CTAB)的自组装体为模板,卵磷脂(PC)为手性添加剂,在n PC∶nCTAB=1∶21时,通过溶胶-凝胶法制备了螺旋介孔二氧化硅纳米棒。利用扫描电镜(FESEM)、透射电镜(TEM)、X-射线衍射以及氮气吸附-脱附等测试手段,对该纳米棒的形貌以及孔结构进行了表征。TEM显示该纳米棒的长度约为50~200 nm,直径约为30~50 nm。X-射线衍射表明孔道呈二维六方排列,虽然FESEM显示纳米棒左右手比例约为1∶1,但通过圆二色谱表征证明该纳米棒在埃尺度下倾向于形成单一手性。结果表明,卵磷脂的手性可以传递到螺旋介孔二氧化硅纳米棒中。 相似文献
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利用手持技术改进测定乙醇分子结构实验 总被引:1,自引:0,他引:1
利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。 相似文献
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V. I. Bol'shakova L. I. Demenkova É. N. Shmidt V. A. Pentegova 《Chemistry of Natural Compounds》1989,24(6):691-694
The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988. 相似文献
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Mustafa R. Ibrahim Zacharia A. Fataftah Paul von Ragu Schleyer Peter D. Stout 《Journal of computational chemistry》1987,8(8):1131-1138
Sets of hydrogen molecule equivalents have been developed which permit the calculation of hydrogenation of different types of carbon-carbon bonds from ab initio total energies (3-21G and 6-31G* basis sets, and, to a more limited extent, for MP2/6-31G* data) of reactants and products. The calculated enthalpies of hydrogenation are in good agreement with experiment for unstrained molecules, with average errors on the order of 2 kcal/mol. The 6-31G* equivalents allow the enthalpies for strained molecules to be calculated accurately, but the 3-21G equivalents do not. The equivalents for both basis sets have been tested by calculating the enthalpies of hydrogenation of carbon-carbon bonds in nitrogen- and oxygen-containing organic molecules, free radicals, and classical carbocations. The results are in good agreement with experiment in most cases. 相似文献
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V. I. Bol'shakova L. I. Demenkova É. N. Shmidt V. A. Pentegova 《Chemistry of Natural Compounds》1988,24(6):691-694
The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae. 相似文献
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由于石化行业的生产需要,其材质的使用具有多样性和广泛性,经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识,根据光谱仪的测试能力及标样的采集,实现了一个或几个元素测量范围的扩展,并对其测量的影响因素进行了研究。 相似文献
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