Electrochemical Performance of Li_4Ti_5O_(12) Prepared by Different Methods

A series of Li4Ti5O12 materials were prepared by three different methods： solvothermal, sol-gel, and solid-state reaction methods. Phase composition, morphology, and particle sizes of the samples were studied by powder X-ray diffraction （XRD） and scanning electron microscopy （SEM）. Electrochemical properties of the samples were investigated by charge-discharge tests. It is demonstrated that both sol-gel and solid-state reaction methods provided good control over the chemical composition and microstructure of the active material, in which sol-gel method yielded a fine Li4Ti5O12 spinel having an initial specific capacity of 146 mAh g-1 and low capacity fade during cycling. Comparatively, the solid-state method is simple and promising to prepare Li4Ti5O12 for commercial applications.     

钯铁合金催化剂的稳定性

分别在酸性和碱性溶液中, 结合旋转圆盘电极技术和电化学石英晶体微天平技术原位考察了钯铁合金催化剂对氧还原反应催化活性的稳定性. 发现在酸性溶液中, 钯铁合金催化剂对氧还原反应的催化活性不稳定, 原因是钯铁合金催化剂在酸性溶液中发生电化学/化学溶解; 在碱性溶液中, 覆盖在电极表面的钯铁合金催化剂的质量及电化学活性面积在电化学扫描过程中不发生明显变化, 保持对氧还原反应的催化活性, 证明钯铁合金催化剂在碱性介质中非常稳定.     

共轭聚合物单分子构象和能量转移特性研究

利用基于宽场显微光学系统的单分子散焦成像技术测量了不同构象poly[2,7-(9,9-dioctylfluorene)-alt-4,7-bis(thiophen-2-yl)benzo-2,1,3-thiadiazole](PFO-DBT)共轭聚合物单分子的光物理与动力学特性.通过分析共轭聚合物单分子的荧光轨迹和对应的发射偶极取向变化识别共轭聚合物单分子发光单元,发现延伸构象下的单分子呈现多发色团发光特性,而折叠构象下的单分子保持高效链间能量转移,呈现单个发色团发光特性.共轭聚合物单分子构象对能量转移效率的影响可用于研究基于共轭聚合物的光电器件和分子器件.     

Modification of single molecule fluorescence using external fields

Controlling and manipulating the fluorescence of single fluorophores is of great interest in recent years for its potential uses in improving the performance of molecular photonics and molecular electronics, such as in organic light-emitting devices, single photon sources, organic field-effect transistors, and probes or sensors based on single molecules. This review shows how the fluorescence emission of single organic molecules can be modified using local electromagnetic fields of metallic nanostructures and electric-field-induced electron transfer. Electric-field-induced fluorescence modulation, hysteresis, and the achievement of fluorescence switch are discussed in detail.     

Structural evolution of silicone oil liquid exposed to Ar plasma

Structure properties of silicone oil serving as a liquid substrate exposed to Ar plasma are investigated in this paper. Under the action of energetic Ar ions, the surface of silicone oil liquid substrate exhibits a branch-like fractal aggregation structure, which is related to the structure evolution of silicone oil liquid from Si--O chain to Si--O network. The radicals from the dissociation of silicone oil molecule into the Ar plasma turns the plasma into a reactive environment. Therefore, the structural evolution of silicone oil liquid substrate and the reactive radicals in the plasma space become possible factors to affect the aggregation of nanoparticles and also the structures and the compositions of nanoparticles.     

磁多极场场参数的理论计算与分析

根据磁多极场的对称性，首先导出了磁多极场磁场分量的泰勒级数展开式，定义了磁多极场的场参数，然后根据毕奥-萨伐尔定律，导出了马鞍型磁多极场线圈的场参数理论计算公式.对各个场参数数量级的大小进行了分析，找出了场参数的递推规律，给出了场参数高阶导数的计算方法，从而能够准确计算整个空间的磁场值.还从简单单根导线计算结果过渡到多根导线或具有某种连续分布的情况. 这对于磁二极场、磁四极场、磁六极场等的应用提供了可靠的理论依据. 关键词： 磁多极场 场参数 马鞍型线圈     

吲哚菁染料的研究进展

吲哚菁染料以其特有的结构, 已成为在光谱增感、光盘存储、生物分析、太阳能电池等方面应用广泛的染料品种之一. 综述了十五年来吲哚菁染料的合成进展, 对其应用现状作了简要介绍.     

考虑溅射损失的RF共振法离子引出和收集

采用PIC-MCC方法研究了AVLIS工程中一维RF共振法离子引出和收集过程，重点研究离子在收 集板上造成的溅射损失以及离子的收集效率.模拟结果表明，RF共振法与平行板静电场法相 比，引出时间较短，碰撞损失和溅射损失较低，收集率较高；增加引出电压，可以缩短引出 时间，降低碰撞损失，但是增加了溅射损失，使得收集率降低；增大磁场强度，使碰撞损失 降低，溅射损失增加，收集率降低. 关键词： AVLIS PIC-MCC 离子引出 溅射     

A reagentless electrochemiluminescent immunosensor for apurinic/apyrimidinic endonuclease 1 detection based on the new Ru(bpy)3/bi-arginine system

Apurinic/apyrimidinic endonuclease 1 (APE-1), a kind of multifunctional protein widely-distributed in the body, plays an essential role in the DNA base excision repair and serves as multiple possible roles in the response of human cancer to radiotherapy and chemotherapy. In this work, an ultrasensitive solid-state electrochemiluminescence (ECL) immunosensor is designed to determine APE-1 based on the new Ru(bpy)₃²⁺/bi-arginine system. The bi-arginine (bi-Arg) is decorated on the Au nanoparticles functionalized magnetic Fe₃O₄/reduced graphene oxide (bi-Arg/Au@Fe₃O₄–rGO) according to the self-assembling and covalent cross-linking interaction to obtain the functionalized nanocomposite of bi-Arg/Au@Fe₃O₄–rGO. Herein, the bi-Arg/Au@Fe₃O₄–rGO plays not only an amplification label to enhance the ECL signal of Ru(bpy)₃²⁺ due to the coreactant of bi-Arg but also an ideal nanocarrier to load numerous secondary antibody. Based on sandwich-type immunoassay format, this proposed method offers a linear range of 1.0 fg mL⁻¹–5.0 pg mL⁻¹ and an estimated detection limit of 0.3 fg mL⁻¹ for the APE-1. Moreover, the reagentless ECL immunosensor also exhibits high sensitivity, excellent selectivity and good stability, which has greatly potential development and application in clinical diagnostics, immunology and biomedical research.     

Decreasing the CTE of Thermoplastic Polyimide by Blending with a Thermosetting System

Chinese Journal of Polymer Science - A series of thermoplastic polyimide resins with a low coefficient of thermal expansion (CTE) were prepared by blending a rigid resin system...