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971.
Shuai Ma Zhijun Xu Ruiqing Chu Jigong Hao Lihong Cheng Guorong Li 《Journal of Materials Science: Materials in Electronics》2014,25(9):3878-3884
ZnO–Bi2O3–B2O3-based varistors doped with each kind of cobalt oxides were prepared by conventional ceramic processing. The effects of CoO, Co2O3 and Co3O4 on the microstructure and the electrical characteristics of varistor samples sintered at 880 °C were investigated separately. Analysis of microstructure indicated the cobalt cations were distributed both in grain regions and grain boundary regions and no crystalline phases containing cobalt were detected in XRD patterns for the samples with various cobalt oxides. All these cobalt oxides could effectively enhance the varistor performance by effectively increasing the nonlinear coefficient and lowing the leakage current, while the breakdown voltage fields increased slightly. Capacitance–voltage characteristics showed the potential barriers of varistor samples increased with the addition of each cobalt oxide. It was found that the addition of same amount of cobalt cations in various cobalt oxides had a different effect on the varistor samples. Best electrical properties were obtained for the varistor sample containing Co3O4, in which the nonlinearity coefficient is 28.5, the leakage current density is 3.4 μA and the breakdown voltage field is as low as 260 V/mm. 相似文献
972.
Gang Wu Hongmei Deng Weijun Wang Kezhi Zhang Huiyi Cao Pingxiong Yang Junhao Chu 《Journal of Materials Science: Materials in Electronics》2014,25(7):3137-3140
LaAl1?x Co x O3 (x = 0, 0.05 and 0.10) thin films were fabricated on quartz substrates by sol–gel method. X-ray diffraction data indicate that all thin films belong to perovskite LaAlO3, and there is no secondary phase. Two obvious Raman peaks are observed in the Raman spectra, and the 113 cm?1 peak is assigned to A1 mode of perovskite LaAlO3 while the 696 cm?1 peak is caused by the Co–O stretching vibration. The band gap of the films decreases from 5.66 to 5.40 eV with the Co composition increasing from 0 to 10 %. The magnetization of the films was investigated, and it enhances significantly with increase of the Co content. 相似文献
973.
分析热湿地区室内空气污染现状,对影响热湿地区室内空气污染因素的独特特征进行总结。介绍国内外热湿环境下挥发性有机物多污染源散发机制的研究现状,指出湿热条件下室内装修家具等具有多污染源的挥发性有机物散发模型及环境影响因素研究的不足,提出对室内温度场、风速场、湿度场、污染物浓度分布进行模拟仿真的研究方向。 相似文献
974.
Yudong Xia Jie Xiong Xin Zhang Kai Hu Fei Zhang Yan Xue Junwei Chu Xiaohui Zhao Bowan Tao Yanrong Li 《Journal of Superconductivity and Novel Magnetism》2014,27(3):871-875
TiN films were successfully prepared on biaxially textured Ni-5 at.%W substrates by pulsed laser deposition (PLD), serving as a seed layer of an all-conductive architecture, i.e., SrRuO3(SRO)/TiN, for coated conductors. The structure and surface morphology of the TiN films were noticeably affected by the substrate temperature and pulse repetition rate. The subsequent conductive SRO and superconducting YBCO layer were deposited on the best sample of TiN buffered Ni-5 at.%W substrates. X-ray diffraction analysis confirmed that the biaxial textures were transferred from the TiN seed layer to the SRO cap layer and YBCO film with excellent out-of-plane and in-plane textures. The superconducting transition curves and the temperature-dependent resistivity of YBCO films on all-conductive buffer and on the traditional insulated CeO2/YSZ/Y2O3 were also investigated. 相似文献
975.
Stability and Half-Metallicity of the (001) and (111) Surfaces of RbN with Cesium Chloride Structure
Xiao-Ping?WeiEmail author Yan-Dong?Chu Huai-Wei?Lu Xiao-Wei?Sun Ting?Song Peng?Guo 《Journal of Superconductivity and Novel Magnetism》2015,28(5):1577-1582
Using the full-potential local orbital minimum-basis method, we study the electronic and magnetic properties of relaxed (001) and (111) surfaces of the bulk RbN within the framework of density functional theory. It is shown that the Rb(N)-terminated (001) surfaces as well as the N-terminated (111) surface are the half-metallicity, while the Rb-terminated (111) surface loses the half-metallicity. The atomic magnetic moments at the N-terminated (001) and Rb(N)-terminated (111) surfaces increase considerably with respect to the corresponding bulk values. In addition, calculations reveal the half-metallicity of the N-terminated (111) surface is more robust than the bulk RbN due to its larger half-metallic gap. Finally, we discuss the stability of the surface. The positive formation energy in the bulk RbN indicates the surfaces unstable, and non-equilibrium growth techniques may be required for the realization of RbN thin films. 相似文献
976.
Shi Liang Xian‐Zhu Yang Xiao‐Jiao Du Hong‐Xia Wang Hong‐Jun Li Wei‐Wei Liu Yan‐Dan Yao Yan‐Hua Zhu Yin‐Chu Ma Jun Wang Er‐Wei Song 《Advanced functional materials》2015,25(30):4778-4787
Delivery of small interfering RNA (siRNA) by nanocarriers has shown promising therapeutic potential in cancer therapy. However, poor understanding of the correlation between the physicochemical properties of nanocarriers and their interactions with biological systems has significantly hindered its anticancer efficacy. Herein, in order to identify the optimal size of nanocarriers for siRNA delivery, different sized cationic micellar nanoparticles (MNPs) (40, 90, 130, and 180 nm) are developed that exhibit similar siRNA binding efficacies, shapes, surface charges, and surface chemistries (PEGylation) to ensure size is the only variable. Size‐dependent biological effects are carefully and comprehensively evaluated through both in vitro and in vivo experiments. Among these nanocarriers, the 90 nm MNPs show the optimal balance of prolonged circulation and cellular uptake by tumor cells, which result in the highest retention in tumor cells. In contrast, larger MNPs are rapidly cleared from the circulation and smaller MNPs are inefficiently taken up by tumor cells. Accordingly, 90 nm MNPs carrying polo‐like kinase 1 (Plk1)‐specific siRNA (siPlk1) show superior antitumor efficacy, indicating that 90 nm could either be the optimal size for systemic delivery of siRNA or close to it. Our findings provide valuable information for rationally designing nanocarriers for siRNA‐based cancer therapy in the future. 相似文献
977.
Navigating Organo‐Lead Halide Perovskite Phase Space via Nucleation Kinetics toward a Deeper Understanding of Perovskite Phase Transformations and Structure–Property Relationships 下载免费PDF全文
Spencer T. Williams Chu‐Chen Chueh Alex K.‐Y. Jen 《Small (Weinheim an der Bergstrasse, Germany)》2015,11(26):3088-3096
Organo‐lead halide perovskite photovoltaics have developed faster than our understanding of the material itself. Using the vast body of work on perovskite processing created in just the past few years, it is possible to create a better picture of this material's complex phase‐transformation behavior. This concept paper summarizes and correlates the current understanding of structural intermediates, kinetic controls, and structure–property relationships of organo‐lead iodide perovskites. To this end, a new way of graphically relating information is developed, allowing the simultaneous mapping of schematic kinetic relationships between all currently prevailing perovskite deposition and growth techniques. 相似文献
978.
979.
本文采用ICP-MS法对高纯碳化硅粉表面的Na、Al、Ti、V、Cr、Mn、Fe、Co、Ni、Cu、Zn、Cd 12种痕量杂质进行测定,用氢氟酸溶液浸提试样表面杂质,用钆做内标补偿基体效应和仪器的漂移,用碰撞反应技术消除多原子离子干扰,通过实验确定最佳优化测定条件。方法检出限为0.005-0.036μg/L;加标回收率为80.0%-120.3%之间;RSD为1.78%-8.95%。方法操作简便、快速、准确。 相似文献
980.
HE Gaofa TANG Yike ZHOU Chu e HE Xiaoping WU Ying College of Mechanical Engineering Chongqing University Chongqing China College of Mechanical Power Engineering Chongqing University of Science Technology Chongqing China Institute of Electronic Engineering China Academe Engineering Physics Mianyang China 《机械工程学报(英文版)》2011,(3):495-500
For the purpose of improving the precision of the inertial guidance system,it is necessary to enhance the accuracy of the accelerometer.Combining the micro-fabrication processes with resonant sensor technology,a high-resolution inertial-grade novel micro resonant accelerometer is studied.Based on the detecting theory of the resonant sensors,the accelerometer is designed,fabricated,and tested.The accelerometer consists of one proofmass,two micro leverages and two double-ended-tuning-fork (DETF) resonators.The sensing principle of this accelerometer is based on that the natural frequency of the DETF resonator shifts with its axial load which is caused by inertial force.The push-pull configuration of the DETF is for temperature compensation.The two-stage micro leverage mechanisms are employed to amplify the force and increase the sensitivity of the accelerometer.The micro leverage and the resonator are modeled for static analysis and nonlinear modal analysis via theory method and finite element method (FEM),respectively.The geometrical parameters of them are optimized.The amplification factor of the leverage is 102,and the sensitivity of the resonator on theory is about 62 Hz/g.The samples of the accelerometer are fabricated with deep reactive ion etching (DRIE) technology which can get a high-aspect ratio structure for contributing a greater sensing-capacitance.The measuring results of the samples by scanning electron microscopy (SEM) show that the process is feasible,because of the complete structure,the sound combs and micro leverages,and the acceptable errors.The frequency of the resonator and the sensitivity of the accelerometer are tested via printed circuit board (PCB),respectively.The result of the test shows that the frequency of the push-resonator is about 54 530 Hz and the sensitivity of the accelerometer is about 55 Hz/g.The amplification factor of the leverage is calculated more accurately because the coupling of the two stages leverage is considered during derivation of the analysis formula.In addition,the novel differential structure of the accelerometer can greatly improve the sensitivity of the accelerometers. 相似文献