产电对微生物燃料电池参数的影响

测试了pH值和电导率的变化规律,分析了MFC开路电压的变化情况,为改善MFC的性能提供理论依据.采用驯化培养的菌种,MFC启动时间更短;在恒温、高温和高底物浓度条件下,开路电压更高、更稳.产物在阳极液中的积累会降低开路电压.阴极液和阳极液的pH值的差值与电流正相关.阳极液的电导率会减小,而阴极液的电导率会增大;阳极液中...     

AlF<Subscript>3</Subscript> coating of LiNi<Subscript>0.5</Subscript>Mn<Subscript>1.5</Subscript>O<Subscript>4</Subscript> for high-performance Li-ion batteries

AlF₃-coating is attempted to improve the performance of LiNi_0.5Mn_1.5O₄ cathode materials for Li-ion batteries. The prepared powders are characterized by scanning electron microscope, powder X-ray diffraction, charge/discharge, and impedance. The coated LiNi_0.5Mn_1.5O₄ samples show higher discharge capacity, better rate capability, and higher capacity retention than the uncoated samples. Among the coated samples, 1.0 mol% AlF₃-coated sample shows highest capacity after charge–discharged at 30 mA/g for 3 cycles, but 4.0 mol% coated sample exhibits the highest capacity and cycling stability when cycled at high rate of 150 and 300 mA/g. The 40th cycle discharge capacity at 300 mA/g current still remains 114.8 mAh/g for 4.0 mol% AlF₃-coated LiNi_0.5Mn_1.5O₄, while only 84.3 mAh/g for the uncoated sample.     

Discontinuous Galerkin method for the coupled Stokes‐Biot model

In this paper, a semi‐discrete scheme and a fully discrete scheme of the Stokes‐Biot model are proposed, and we analyze the semi‐discrete scheme in detail. First of all, we prove the existence and uniqueness of the semi‐discrete scheme, and a‐priori error estimates are derived. Then, we present the same conclusions for the fully discrete scheme. Finally, under both matching and non‐matching meshes some numerical tests are given to validate the analysis of convergence, which well support the theoretical results.     

An incremental bundle method for portfolio selection problem under second-order stochastic dominance

Numerical Algorithms - We propose a preconditioner to accelerate the convergence of the GMRES iterative method for solving the system of linear equations obtained from discretize-then-optimize...     

The Calibration Method of TOFr in the STAR Experiment

a tray of time of flight detector based on mrPc technology took part in the physics run of star both in p+p and d+au collisions in 2003. together with the information from the time Projection chamber(tPc) and the pseudo–vertex Position detector (pvPd) of the star experiment,corrections are done to calibrate the new prototype tof. the intrinsic time resolution of tofr reaches 85ps and it extends the π/K and K/p separation up to 1.6gev/c and 3.0gev/c respectively.     

Controlled growth of uniform nanoflakes-built pyrite FeS<Subscript>2</Subscript> microspheres and their electrochemical properties

Nanoflakes-built pyrite FeS₂ microspheres were synthesized through a simple solvothermal process in mixed solvents of N, N-dimethytformamide and ethylene glycol without using any surfactant. Both the composition of the solvents and urea were key factors for the formation of the uniform products. It was found that the flake-like intermediate products transformed into FeS₂ nanoflakes in situ in the early stage and Ostwald ripening growth mechanism would contribute to the uniformity of the final products. Electrochemical studies revealed that the nanoflakes-built pyrite FeS₂ microspheres exhibited large lithium storage capacities. This method can be easily controlled and is expected to be extendable to the fabrication of other metal chalcogenides with controlled shape and structure.     

对数态Tavis-Cummings模型中辐射场的非经典性

本文研究了任意初态的双光子Tavis-Cummings模型的演化规律,作为例子,讨论了初始时刻两个原子均处于基态而光场为对数态时场的压缩效应,光子的聚束和反聚束效应.     

分布反馈光纤激光器的研制

利用相位掩膜板,直接在掺饵光纤上紫外写入π／２相位光栅,研制出１０ｃｍ长相移分布反馈（ＤＦＢ）光纤激光器,并对其调制特性进行了研究。     

F-P滤波器对啁啾光脉冲脉宽的扩展和压缩

导出了啁啾光脉冲通过F P滤波器后输出脉冲光强的解析表达式。在此基础上 ,对啁啾光脉冲通过F P滤波器后其脉冲宽度的变化进行了研究。结果表明 ,对于一确定的滤波器 ,其对输入脉冲脉宽的影响与输出脉冲的宽度及啁啾因子的大小有关