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1.
二氧化锡纳米粒子的制备及表征   总被引:25,自引:0,他引:25  
用胶体沉淀与微乳液法制得二氧化锡纳米粒子,并用X射线衍射光谱、紫外漫反射吸收光谱、IR吸收谱等进行了表征,结果表明:二氧化锡粒子尺寸至少少于6nm时,才能出现明显的量子尺寸效应。十二烷基苯磺酸修饰的SnO2纳米微粒,粒度分布均匀且单分散性好,表面活性剂以SO^2-3形成与Sn^4+结合,使得纳米粒子稳定性较好。  相似文献   

2.
用环氧树脂对有机硅共聚物进行改性,得到环氧改性有机硅树脂,采用红外光谱对其结构进行表征.结果表明:环氧改性有机硅树脂中形成的Si-O、Si-C骨架,使树脂涂层具有优异的粘结性能.采用偶联剂对纳米二氧化钛、纳米掺锑二氧化锡和纳米二氧化硅混合粒子进行改性,将此纳米粒子作为热反射涂料的颜填料使用,结果表明:当纳米粒子含量在3%时,涂膜的耐腐蚀性能最佳.  相似文献   

3.
分散剂对纳米相二氧化锡制备的影响   总被引:15,自引:0,他引:15  
采用化学沉淀法 ,通过在不同阶段加入适量的分散剂 ,制备了纳米相二氧化锡 .以 PCS、TEM详细研究了二氧化锡胶体和粉体的粒子形貌、大小及分布 .结果表明 :二氧化锡胶体颗粒分散均匀 ,粒径约 3nm左右 ,分布范围窄 ;80℃烘干后粒径约 8nm左右 ;70 0℃煅烧后颗粒为球型 ,团聚体少 ,颗粒粒径小于 5 0 nm.最后 ,定性分析了分散剂在纳米相二氧化锡制备中的分散机理 .  相似文献   

4.
采用离子交换除氯水解法和有机溶剂共沸干燥方法制备得到导电性好的掺锑二氧化锡纳米粉末,用XRD对掺锑二氧化锡纳米粉末的结构进行表征;采用粉末微电极技术,对掺锑二氧化锡纳米粉末的电化学性质进行了研究.  相似文献   

5.
Fe3O4磁纳米粒子的炔基修饰包括:纳米磁性Fe3O4粒子的制备,硅胶包覆Fe3O4磁粒子,氨基修饰硅胶包覆的磁粒子,炔基修饰氨基修饰后的磁粒子.并采用苄基叠氮与所制备的炔基修饰磁Fe3O4纳米粒子进行click环加成反应.通过SEM、BET、XRD和VSM分别对Fe3O4和硅胶包覆Fe3O4的表面形貌、比表面积、晶型结构和磁性能进行表征;利用UV-Vis对磁性Fe3O4粒子表面的炔基进行半定量分析;采用FTIR对产物表面基团做定性分析.结果表明,Fe3O4磁纳米粒子平均粒径为180±20 nm,粒子呈球  相似文献   

6.
利用水热法处理五水四氯化锡溶胶制备二氧化锡纳米粉,试验纳米二氧化锡纳米粉催化合成乙酰水杨酸的研究,并研究了酯化反应的优化条件,结果表明:纳米二氧化锡呈现出较高的催化活性,其催化合成乙酰水杨酸产率比以浓硫酸为催化剂的产率高,也明显高于普通的二氧化锡的产率,且纳米二氧化锡催化剂安全无毒,克服了浓硫酸的强腐蚀性、强氧化性、难于与产品分离、对环境污染大等缺点,纳米二氧化锡可望成为一种较好的能取代浓硫酸且对环境友好的催化剂。  相似文献   

7.
二氧化锡纳米纤维具有优异的物理化学性能,并且具有易合成的特点,已被广泛的应用于传感领域,它不仅仅可以被用于很多气体的探测,还可以进行湿度、紫外线的探测。文章在叙述二氧化锡纳米纤维所具备的优异性能的基础上,简单介绍了二氧化锡纳米纤维探测气体、湿度、紫外线的原理,并例举了近几年二氧化锡纳米纤维在传感领域的应用。  相似文献   

8.
首次以锡酸钠和葡萄糖为原料利用水热法成功合成了由碳包覆二氧化锡(SnO2@C)纳米链形成的多环三维(3-D)超结构材料.利用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X-射线粉末衍射仪(XRD)和拉曼测试仪(Raman)对样品进行了表征.将8 nm厚的碳包覆二氧化锡纳米链(SCNCs)试样用于锂离子电池负极材料上,电流为300 mA·g-1时其可逆放电容量大于760 mAh·g-1,100次充放电后还能保持85%的容量.通过原位合成在SCNCs表面负载Pt、Ru纳米粒子,用于甲醇的氧化,具有优越的电化学催化活性.  相似文献   

9.
二氧化锡超微粒子气敏薄膜的复数阻抗谱研究   总被引:1,自引:0,他引:1  
用直流气体放电活化反应蒸发法制备了二氧化锡超微粒子薄膜,测量了薄膜的阻抗谱,验证了超微粒子薄膜的内部模拟等效电路。研究了温度、还原性气体以及热处理对阻抗谱的影响,并用氧吸附理论和晶界热垒理论定性地解释了这些现象。  相似文献   

10.
乙二醇溶剂中纳米TiO2的制备   总被引:1,自引:0,他引:1       下载免费PDF全文
利用化学沉淀法,以乙二醇作为溶剂,氢氧化钠、四氯化钛为原料,在非水体系中,制备纳米级氧化钛。用FT-IR、XRD、TEM研究中间粒子和纳米粒子的晶体结构,证明中间粒子表面有有机物包覆,在500℃的高温下煅烧,得到纳米TiO2,粒子平均粒径为(17nm)。通过光催化降解苯酚实验,证明其具有较好的光催化性能。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

13.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

14.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

15.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

16.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

17.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

18.
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of  相似文献   

19.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

20.
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