改革物理实验课教学,提高实验课的教学质量

根据多年的物理实验教学经验，阐明了物理实验教学改革应重视的问题，并提出了几点改进措施。     

Quantum wire heterostructure for optoelectronic applications

Quantum wire (QWR) heterostructures suitable for optoelectronic applications should meet a number of requirements, including defect free interfaces, large subband separation, long carrier lifetime, efficient carrier capture. The structural and opticl properties of GaAs/AlGaAs and InGaAs/GaAs quantum wire (QWR) heterostructures grown by organometallic chemical vapor deposition on nonplanr substrates, which satisfy many of these criteria, are described. These crescent-shaped QWRs are formed in situ during epitaxial growth resulting in virtually defect free interfaces. Effective wire widths as small as 10nm have been achieved, corresponding to electron subband separations greater than K_BT at room temperature. The enhanced density of states at the QWR subbands manifests itself in higher optical absorption and emission as visualized in photoluminescence (PL), PL excitation, amplified spontaneous emission and lasing spectra of these structures. Effective carrier capture into the wires via connected quantum well regions, which is important for enhancing the otherwise extremely small capture cross section of these wires, has also been observed. Room temperature operation of GaAs/AlGaAs and strained InGaAs/GaAs QWR lasers with threshold currents as low as 0.6mA has been demonstrated.     

牛顿第二定律实验中的误差分析

本文是通过对加速度的实验值和理论值进行比较和分析，给出误差的合理范围。     

Global stability and periodic solution of the viral dynamics

It is well known that the mathematical models provide very important information for the research of human immunodeficiency virus-type 1 and hepatitis C virus (HCV). However, the infection rate of almost all mathematical models is linear. The linearity shows the simple interaction between the T cells and the viral particles. In this paper, we consider the classical mathematical model with saturation response of the infection rate. By stability analysis we obtain sufficient conditions on the parameters for the global stability of the infected steady state and the infection-free steady state. We also obtain the conditions for the existence of an orbitally asymptotically stable periodic solution. Numerical simulations are presented to illustrate the results.     

绝缘表面和气体导电与湿度的关系

湿度对绝缘体表面电导和气体电导有一定的影响，但通常在湿度传感器的研究中忽略了气体电导的贡献。本文通过特殊设计装置来区分表面电导和气体电导，并分别从实验和理论上进行了定性的研究。     

Radiation pasteurised oil palm empty fruit bunch fermented with Pleurotus sajor-caju as feed supplement to ruminants

In solid state fermentation, Pleurotus sajor-caju has been found to be able to degrade at least 30% oil palm empty Fruit Bunch (EFB) fibre leaving 70 % useful materials. Conditions under which fermentation carried out were investigated. It was found that, in the temperature range between 25– 28 °C, relative ph between 6–8, moisture between 60–70 % and medium composition of CaCO₃: rice bran 2 %: 5 % were the optimum conditions. The results showed in fermented products that, there were substantial reduction in cellulosic component such as Crude Fiber (CF, 18 %); Acid Detergent Fibre (ADF, 45 %), Neutral Detergent Fibre (NDF, 61 %) and Acid Detergent Lignin (ADL, 14 %). However, Crude Protein (CP, 10%) increased resulted from single cell protein enrichment of mycelial microbial mass. The mass reductions of substrate in fermentation process corresponds to the CO₂ released during fermentation. Hence, attributable to the decreased in content of CF, ADF, NDF, and ADL. The digestibility study has also been carried out to determine the useful level of this product to ruminant. Aflatoxin content was detected low in both the initial substrates and products. Based on nutritional value and low content of aflatoxin, the product is useful as a source of roughage to ruminant.     

延长速调管使用寿命的方法

描述了一种延长EPR波谱仪中速调管使用寿命的方法.根据这种方法,只要正确地调谐微波桥的工作状态和适当地调整功率电平器的功率校正电平.即使对于已经严重老化的速调管仍然可以继续使用一段时间,维持仪器的正常运行.     

Hypersurface with Constant Main Curvature Symmetric Functions

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横向位移双曝光散斑图维纳谱的信息分布

讨论了横向位移双曝光散斑图维纳谱的信息分布，并由此导出杨氏纹图的一般表达式。讨论了条纹可见度与应变，面内转动，照明光束直径与条纹图图空间坐标的关系，指出了在条纹可见度影响下最大可见条纹数目。还讨论了散斑衬比与衍射晕的关系。