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941.
Gai Li Teng Wang Yi Zhu Shengyi Zhang Changjie Mao Jieying Wu Baokang Jin Yupeng Tian 《Applied Surface Science》2011,257(15):6568-6572
By dipping-lifting in sol-gel solution and reducing process, the graphene/TiO2 composite film on the glass plate was first prepared. Then, the Ag/graphene/TiO2 composite film was fabricated by interface reaction with AgNO3 and N2H4·H2O on the surface of graphene/TiO2 composite film. The characterization results show that the uniform porous TiO2 film is made up of the anatase crystal, and the Ag/graphene/TiO2 composite film is constructed by doping or depositing graphene sheets and Ag nanoparticles on the surface of TiO2 film. The photoelectrochemical measurement results indicate that the Ag/graphene/TiO2 composite film has an excellent photoelectrochemical conversion property. 相似文献
942.
L.D. ZhangW.L. Liu C.L. XiaoJ.S. Yao Z.P. FanX.L. Sun X. ZhangL. Wang X.Q. Wang 《Journal of magnetism and magnetic materials》2011,323(23):3087-3091
The use of a block copolymer, poly (styrene)-b-poly (acrylic acid) (PS-b-PAA) to prepare a magnetic nanocomposite was investigated. Poly (styrene)-poly (t-butyl acrylate) block copolymer, being synthesized by atom transfer radical polymerization, was hydrolyzed with hydrochloric acid for obtaining PS-b-PAA. The obtained PS-b-PAA was then compounded with the modified γ-Fe2O3, and subsequently the magnetic nanocomposite was achieved. The products were characterized by 1H NMR, FTIR, gel permeation chromatography, thermogravimetric analysis, transmission electron microscopy and vibrating sample magnetometer. The results showed that the nanocomposites exhibited soft magnetism, with the mean diameter of 100 nm approximately. 相似文献
943.
Li KA Zhang RM Zhang F Zhao JL Li YJ Wang XF Zheng LF Hu YS Zhang GX 《Magnetic resonance imaging》2011,29(8):1101-1109
Objective
The objective was to analyze the correlation of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) with vascular endothelial growth factor (VEGF) protein expression and to assess the potential application of DCE-MRI to the rabbit cerebrospinal fluid (CSF) metastasis model.Methods
Thirty New Zealand rabbits were divided into experimental and control groups. In the experimental group, VX2 tumor cells were injected into the subarachnoid space at the plane of cisterna magna in 24 rabbits. In the control group, physiological saline was injected into the subarachnoid space at the plane of cisterna magna in six rabbits. DCE-MRI was performed at multiple time points, and several pharmacokinetic parameters, including Ktrans, Kep and Ve, were calculated. Also, VEGF levels in plasma and CSF were evaluated by enzyme-linked immunosorbent assay prior to DCE-MRI examination. After DCE-MRI examination, the rabbits were sacrificed, and the corresponding tumor specimens were harvested. Hematoxylin–eosin staining and VEGF immunohistochemical staining were carried out, and VEGF expression in the specimens was evaluated by the immunohistochemical scoring system.Results
Vascular endothelial growth factor positive staining was localized in the cytoplasm and cell membranes of tumor cells, as well as in a subset of epithelial cells. Both VEGF immunohistochemical scores and VEGF expression in CSF and plasma exhibited positive correlations with Ktrans and Kep values as demonstrated by rank correlation statistical analysis.Conclusions
Vascular endothelial growth factor expression in plasma and CSF in the CSF metastasis model was higher than in normal tissues. Therefore, DCE-MRI reliably indicated VEGF expression in the rabbit CSF metastasis model. 相似文献944.
通过燃烧法制备了Yb3+-Tm3+共掺的Y2O3纳米粉体,并对样品在980 nm激光照射下的上转换发光特性进行了研究.实验发现,样品在可见光区域能够产生强烈的蓝色发光(476 nm和487 nm)和较弱的红色发光(约650 nm),而且同时观察到了两个紫外发光峰1I6→3H6 (~297 nm)和1
关键词:
2O3:Yb3+')" href="#">Y2O3:Yb3+
3+')" href="#">Tm3+
上转换光谱
敏化
紫外发光 相似文献
945.
在丙型肝炎病毒(HCV)的基因复制和蛋白质成熟的过程中, 非结构蛋白5B(NS5B)作为RNA依赖的RNA聚合酶起到了重要的作用. 抑制NS5B聚合酶可以阻止丙型肝炎病毒的RNA复制, 因此成为一种治疗丙型肝炎的有效方法. 通过计算机方法进行虚拟筛选和预测NS5B聚合酶抑制剂已经变得越来越重要. 本文主要采用机器学习方法(支持向量机(SVM)、k-最近相邻法(k-NN)和C4.5决策树(C4.5 DT))对已知的丙型肝炎病毒NS5B蛋白酶抑制剂与非抑制剂建立分类预测模型. 1248个结构多样性化合物(552个NS5B抑制剂与696个非NS5B抑制剂)被用于测试分类预测系统, 并用递归变量消除法选择与NS5B抑制剂相关的性质描述符以提高预测精度. 独立验证集的总预测精度为84.1%-85.0%, NS5B抑制剂的预测精度为81.4%-91.7%, 非NS5B抑制剂的预测精度为78.2%-87.2%. 其中支持向量机给出最好的NS5B抑制剂预测精度(91.7%); C4.5决策树给出最好的非NS5B抑制剂预测精度(87.2%); k-最近相邻法给出最好的总预测精度(85.0%). 研究表明机器学习方法可以有效预测未知数据集中潜在的NS5B抑制剂, 并有助于发现与其相关的分子描述符. 相似文献
946.
通过静态失重法研究了十二烷基苯磺酸钠(SDBS)与六亚甲基四胺(HA)在盐酸溶液中对Q235钢的协同缓蚀效应, 并采用分子动力学模拟从缓蚀剂膜抑制腐蚀粒子扩散的角度对其缓蚀机理进行分析. 结果显示: SDBS和HA单独使用时, 最高缓蚀效率分别为82.82%和79.46%, 复配后最高缓蚀效率可达到92.78%; 与两种缓蚀剂单独使用时相比, SDBS与HA复配后缓蚀剂膜体系中的自由空间明显下降, 削弱了膜内缓蚀剂分子的自扩散能力, 腐蚀粒子在缓蚀剂膜携带下的被动迁移也随之减弱; SDBS与HA复配能更有效抑制腐蚀粒子在缓蚀剂膜中的扩散, 也就是说复配后的缓蚀剂具有更好的缓蚀性能. 相似文献
947.
以未使用和使用氢氧化钠溶液处理的花生壳为碳源分别制备出微孔炭PSC-1和PSC-2.PSC-1和PSC-2的比表面积分别为552和726m2·g-1,其主要孔径都约为0.8nm.用PSC-1和PSC-2制备的电极和对称型超级电容器的循环伏安曲线均接近矩形,表明其具有良好的电容特性.在以微孔炭电极为工作电极、铂电极为对电极和银/氯化银电极为参比电极组成的三电极体系测量表明,在0.1A·g-1的电流密度下,PSC-1和PSC-2的比电容达到233和378F·g-1.经过1000次恒电流充放电循环后,在三电极体系和超级电容器中电极均表现出良好的稳定性和电容保持率.基于实验结果探讨了微孔炭的形成机理及其结构与电化学性质之间的联系. 相似文献
948.
研究了在铟锡氧化物(ITO)导电玻璃上组装的纳米钛酸锶薄膜光电极在模拟日光照射下对不锈钢的抗腐蚀保护性能.通过溶胶-凝胶法在添加和不添加十六烷基三甲基溴化铵(CTAB)表面活性剂的情况下制得了不同形貌的钛酸锶粉体.X射线衍射(XRD)和高分辨扫描电子显微镜(SEM)表征结呆表明,两种方法合成的钛酸锶均为钙钛矿型结构,但添加CTAB后得到的钛酸锶颗粒分散均匀,平均粒径为90 nm左右.采用紫外-可见漫反射光谱对钛酸锶薄膜的光物理性质进行了研究,发现其光吸收范围在紫外光区,而且通过CTAB协助合成的钛酸锶在小于380 nm光区较非CTAB协助合成的钛酸锶有更强的吸收.以0.1 mol·L-1NaOH+0.2 mol·L-1Na2S溶液为光电极反应的电解质,测试了钛酸锶薄膜电极对304不锈钢在0.5 mol·L-1的NaCI腐蚀溶液中的光电化学缓蚀性能.304不锈钢在CTAB改性钛酸锶薄膜光电化学保护或不保护条件在0.5 mol·L-1NaCl+0.05 mol·L-1HCl腐蚀溶液中腐蚀6h前后的表面金相图表明,钛酸锶薄膜具有优异的光电化学抗腐蚀性能. 相似文献
949.
950.
The present work reports on the synthesis, characterization and performance of a new iron(III)-containing ionic liquid [(C4H9)2-bim][FeCl4] (Fe-IL, bim = benzimidazolium) as an electrocatalyst for nitrite and bromate reduction. The melting point of Fe-IL is 70 °C.
Thermal behavior of the Fe-IL was studied by differential scanning calorimetry and thermalgravimetry. The value of magnetic
moment and its temperature dependence were measured. A conductive carbon paste electrode (Fe-IL/CPE) comprised of Fe-IL and
carbon powder was fabricated by the direct mixing method. The Fe-IL has double functions—a binder and an electrocatalyst.
The electrochemical behavior and electrocatalysis of Fe-IL/CPE have been studied by cyclic voltammetry. The Fe-IL/CPE shows
excellent electrocatalytic activities toward nitrite and bromate reduction. The detection limit and the sensitivity are 0.01 μM
and 100.58 μA μM−1 for nitrite, and 0.01 μM and 83.11 μA μM−1 for bromate detection, respectively. This work demonstrates that the Fe-IL may become a new kind of functional material in
constructing chemicals and biosensors. 相似文献