4—羟基—4′—X—二苯酮的合成

本文研究了4-羟基-4′-x-二苯酮的合成方法,其中x可为H、CH_3、Br、Cl、OH、CH_3O,反应采用三氯化铝催化,由对甲氧基苯甲酰氯与x-取代笨反应,一步得到目标分子。应用本反应时间短、产率都在75％以上。     

锌镀层的晶体取向

以Ｄ－Ⅰ季胺化合物为添加剂的碱性锌酸盐溶液，在多晶铁基体上用恒电位方法电沉积锌，用 Ｘ－射线衍射法研究沉积层锌晶体的取向．测定了过电位和添加剂浓度对晶体取向的影响，获得一 个重要的结果：电沉积层的（１１２０）择优取向随电沉积过电位的降低和添加剂浓度的提高而增强． 并认为是由于添加剂对各晶面的阻化作用不同，导致镀层形成择优取向，满意地解释了有关的实验 结果．     

现代远程教育模式下教学方式的改变

现代远程教育是对传统教育的补充，是未来教育的重要组成部分，随着现代远程教育的普及，教育方式需要做好相应的改变。     

MFV-Class： a multi-faceted visualization tool of object classes

Classes are key software components in an object-oriented software system. In many industrial OO software systems, there are some classes that have complicated structure and relationships. So in the processes of software maintenance, testing, software reengineering, software reuse and software restructure, it is a challenge for software engineers to understand these classes thoroughly. This paper proposes a class comprehension model based on constructivist learning theory, and implements a software visualization tool (MFV-Class) to help in the comprehension of a class. The tool provides multiple views of class to uncover manifold facets of class contents. It enables visualizing three object-oriented metrics of classes to help users focus on the understanding process. A case study was conducted to evaluate our approach and the toolkit.     

Physiological response of Tamarix ramosissima under water stress along the lower reaches of Tarim River

Tarim River within the boundaries of Xinjiang is the longest inland river in China and its overall length is 2300 km (the main stream is 1321 km). Because of the increasing population in the region and large-scale ex- ploitation of water and soil resource…     

Fabrication and photoluminescence of GaN nanowires prepared by ammoniating GaeO3/BN films on Si substrate

GaN nanowires were successfully prepared on Si（111） substrate through ammoniating Ga203/BN films deposited by radio frequency magnetron sputtering system. The synthesized nanowires were confirmed as hexagonal wurtzite GaN by X-ray diffraction, selected-area electron diffraction and Fourier transform infrared spectra. Scanning electron microscopy and transmission electron microscopy revealed that the grown GaN nanowires have a smooth and clean surface with diameters ranging from 40 to 160 nm and lengths typically up to several tens of micrometers. The representative photoluminescence spectrum at room temperature exhibited a strong UV light emission band centered at 363 nm and a relative weak purple light emission peak at 422 nm. The growth mechanism is discussed briefly.     

Imaging mechanical shear waves induced by piezoelectric ceramics in magnetic resonance elastography

MRI is a noninvasive medical imaging modality for stimulating the development of medical diagnosis tech-nology. Scientists and engineers are now trying to extend the use of traditional MRI scanner to a wider field. The magnetic resonance elastography (MRE…     

基于图像外形的多尺度相关性检索算法

采用数学分析的方法比较了图像检索算法中常用的2种坐标系，发现极坐标更加有利于图像的多尺度处理．设计的边缘序列点的插值算法，既保证了2个比较序列的长度相同，叉保留了序列中所有的边缘特征点．根据极坐标下边缘序列点的插值算法和相似轮廓在空间距离上相关性最大的特点，给出了多尺度相关性的检索算法（MSRA），该算法具有对图像尺度变化不敏感，而对图像轮廓变化敏感的特性．通过对自然类图像库和人工类图像库200幅图像的检索，表明该算法的性能高于常用的图像检索算法，与笛卡儿坐标下普通边缘点傅里叶搜索算法（CBPFD）相比，MSRA的搜索识别率在自然类图像库中高于CBPFD的29％，而在人工类图像库中几乎是CBPFD的2．5倍．     

MATLAB与.NET平台接口技术的研究

通过比较已有MATLAB与.NET平台接口调用技术,提出了一种采用对象化包装MATLAB引擎库函数的方法,该方法将MATLAB中由C/C 方式提供的引擎库函数进行对象化包装,使得由普通的函数调用转化为.NET平台上对象方法的调用.实验结果表明.NET平台下的托管代码能更好的调用MATLAB中的引擎库函数,托管代码语言(如C#)与MATLAB的数据交互能力有一定提高.