基于ODMG—93标准的面向对象视图集成机制

模式集成多数据库系统中需要解决的关键问题之一，己存在的大多数面向多数据库系统都采用了面向对象视图机制来建立集成模式。为了满足基于ＣＯＲＢＡ的ＣＩＭＳ信息集成平台呆订成的需要，本文提出了一种基于数据库管理组ＯＤＭＧ的ＯＤＭＧ－９３标准的视图集成机制并通过一个完整的例子说明了这种视图机制在模式集成中的应用。     

Determining protein loop conformation using scaling-relaxation techniques

We recently developed a rapid loop closure algorithm in which bond lengths are scaled to constrain the ends of a segment to match a known distance and then gradually relaxed to their standard values, with boundary constraints maintained. Although the algorithm predicted the Zif286 zinc-finger loop to within approximately 2 A, it had a serious limitation that made its more general use tentative: it omitted the atomic environment of the loop. Here we report an extension of the algorithm to take into account the protein environment surrounding a given loop from the outset of the conformational search and show that it predicts structure with an efficiency and accuracy that could not be achieved without continuous environmental inclusion. The algorithm should be widely applicable to structure determination when complete experimental information is unavailable.     

电子称在化工生产中的应用

针对化工生产环境的特点对电子称重仪器在化工计量中的正确选择和使用作一些分析阐述。     

激光辐照对不同饵料微藻生长的影响

利用Nd:YAG激光(波长1.06μm,功率5W,照射时间0.5-3min)和Ar 激光(波长:488nm,功率70mw,照射时间5-20min)分别照射角毛藻和叉鞭金藻,辐照后进行细胞增殖和生长速率的测定。实验结果表明:照射剂量为1min的Nd:YAG激光及剂量为5min的Ar 激光对叉鞭金藻有较明显的促长效果,这两种激光处理组的细胞增殖量在辐照后的两天内较对照组分别高42.9%和48.1%,但这种促长效果随时间的推移逐渐消失。不同剂量的两种激光辐照角毛藻后,在延滞期均出现生长抑制现象,但进入指数生长期或传代培养后,剂量为1min的Nd:YAG激光及剂量为10min的Ar 激光对角毛藻有明显的促长效果,其中在指数生长期1min剂量的Nd:YAG激光处理可促长27.0%,传代培养后10min的Ar 激光处理组生长速率提高达51.2%。本文对不同激光及不同激光参数条件下,两种饵料藻的耐受性及生长特性的差异也进行分析探讨。本实验结果不仅证实了已有研究的推论,还展示出激光技术在饵料藻种选育中的应用前景。     

Growth and optical property of zinc oxide thornballs

A new microstructure, thornball, of zinc oxide (ZnO) was synthesized by a very simple solid vapor deposition process under lead oxide (PbO) atmosphere. The microthornballs consist of numerous needles, which extend outwards in all directions symmetrically. They have dimensions of 120 μm in diameter, while the average diameter of the needles is about 100-200 nm. The needles on the balls grow along the 〈0 0 0 1〉 orientation and have gradient compositions along radial. Control experiments proved that PbO played an important role in the growth. Additionally, photoluminescence property was observed and provided the evidence that PbO did not deteriorate the optical properties of ZnO thornballs. This kind of microstructures has potential applications in the field of photochemical catalysis.     

Functionalization of soluble polymers

Summary The synthesis of di-(4-formylphenyloxyethyl) poly(oxyethylene) and the corresponding oxime derivative are described. Kinetic aspects of the reaction of the dichloro telechelic with 4-hydroxy benzaldehyde are investigated and discussed.     

PMD Measurement of Hollow-Core Photonic Bandgap Fiber by Investigating Power Penalty of Optically Generated Microwave Signals

A simple method based on carrier suppression modulation for measuring first-order polarization-mode dispersion of hollow-core photonic bandgap fiber (HC-PBGF) is proposed and investigated. By adjusting the incident optical wavelength and measuring the power penalty of optically generated microwave signals, the wavelength-dependent differential group delay (DGD) in HC-PBGF can be obtained. Moreover, this proposed method is chromatic-dispersion-insensitive. The experimental results indicate that a segment of 20-m HC-PBGF exhibits highly birefringent DGD of 25, 59, and 84 ps with measurement error less than 2 ps for the incident optical wavelength of 1560, 1575, and 1580 nm, respectively