New BCN Fibres for Strong Ultraviolet and Visible Light Luminescence

Novel B3CN3 fibres with a special structure have been synthesized by a pyrolysis process. High-resolution TEM analysis shows that the as-prepared B3CN3 fibres can be described as a nanofibre-interweaved network. Strong photoluminescence at 370 nm and 700 nm from the as-prepared B3 CN3 fibres are observed at room temperature, which suggests that B3 CN3 is a promising ultraviolet- and visible-light-emitting material.     

Effects of Post-Thermal Treatment on Quality of SiC Grown by PVT Method

We report the effects of post-thermal treatment on the quality of 2-inch 6H-SiC wafer cut from a crystal boule grown by physical vapour transportation method. The full widths at half maximum of x-ray diffraction rocking curves measured on sites across the 2-inch wafer become narrower, indicating the quality improvement after a three-step post-thermal treatment. It is found that the most common defects such as micropipes and inclusions can be significantly reduced after the treatment. Our results show that the post-thermal treatment is an effective route to improve the quality of SiC single crystals.     

垂直上升管内液体横掠流动传热特性研究

本文对单相水和单相油横掠流动时的平均换热特性进行了实验研究,对试验的结果进行了分析和讨论,并对实验数据进行关联,得到了垂直上升管内单相水和单相油横掠流动时的换热准则关系式。结果表明,狭窄空间条件下的液体横掠柱体时的流动换热对液相Re数的依赖,较大空间条件下的流动换热相比明显减小,并对单相水和单相油横掠流动时的换热性能进行了比较。     

圆形振动膜ZnO压电微传声器的研制

本文介绍了一种新型圆形振动膜ZnO压电微传声器的制备，并对传声器制备的工艺过程进行了较为详细的描述。圆形振动膜的压电传卢器与以前方形振动膜结构设计相比，较大幅度提高了传声器的灵敏度和成品率，灵敏度达到-70dB（相对于1V／Pa），成品率达到80％。     

采用Authorware 5制作现代光学实验多媒体课件

我们采用目前最流行的多媒体制作软件Authorware 5开发工具，把现代光学实验原理，公式推导，实验内容，步骤等字材料，以及用CCD采集的干涉图像，优美的背景音乐及解说词等多种数学信息，制作成多媒体课件，可直接用于远程教育，有较大的实用价值。     

用二维复式晶格有限集团模型计算聚乙炔的电子结构

以二维复式晶格作为有限系统的集团模型,在紧束缚近似下,计算了π电子在最近邻及次近邻跳跃集团的态密度.讨论了不同结构参数对态密度及带宽的影响.     

Three New Diarylpropanes from Dioscorea composita

Three new diarylpropanes were isolated from the dried rhizomes of Dioscorea composita Hemsl., and their structures were determined as 1, 3-bis-(2-hydroxy-4-methoxyphenyl) propane (1), 1, 3-bis-(2, 4-dihydroxyphenyl)propane (2), 1-(2′-hydroxy-4′-O-β-D- glucopymnosy-phenyl)-3-(2“, 4“-dihydroxyphenyl)propane (3), by spectroscopic analysis, respectively.     

Microscopic Theory of Blue Phases Ⅰ and Ⅱ of Liquid Crystal

The microscopic theory of the blue phases of chiral liquid crystal is proposed. Beginning with the potential between two molecules, by using the cell model of liquid, applying statistical physical method, the distribution function and the free energy of the system are obtained. By using variational approach and zero-order approximation, the differential equation that the order parameter tensor of the blue phase can satisfy is obtained. Then we change the differential equation to the eigenequation problem in quantum mechanics. Considering the symmetry of the blue phases,the order parameter tensors of blue phases Ⅰ and Ⅱ can be made up of the eigenvectors. Our results are the same as the results of Ginzberg-Landau‘s phenomenological theory. The parameters in the order parameter tensors that we calculate in the located system are close to the predecessors‘ results.     

Aggregation Properties of an Amphiphilic Methanofullerene Derivative in THFH_2O Solvent Mixtures

Water-soluble fullerenes not only have a number of important applications in biological chemistry1, but also form ordered aggregate structures that can be utilized in materials science2. There are reports that some water-soluble fullerene derivatives can form ordered structures in water, such as vesicle, nanorod and nanoparticle2-5. However, relatively few reports on the aggregation process have been reported. Knowledge of factors that affect the cluster formation in solution is of consider…     

锡(Ⅳ)-偶氮邻苯二酚苯基荧光酮-吐温-80体系分光光度法测定岩石中微量锡

pH值在7.0-8.5的范围内，锡与偶氮邻苯二酚苯基荧光酮、吐温－80形成络合物，其最大吸收峰556nm，摩尔吸光系数2.9×10^5L·mol^-1·cm^-1，锡的含量在0－6μg/25mL范围内遵守比耳定律，本方法对干扰离子的影响和消除进行了研究，本方法已被用于岩石样中锡的测定，结果满意。