Production and structural features of a water-soluble polysaccharide from a mutant strain of Agrobacterium sp.

We have developed a mutant strain derived from Agrobacterium sp. ATCC 31750, which produces a water-soluble polysaccharide having potential utility to the food, feed, pharmaceutical and cosmetic industries. A high concentration of product (15 g/L) is obtained by 48 h cultivation of the mutant strain under optimized fermentation conditions. The water-soluble polysaccharide obtained from cultures of the mutant strain beta82 has Glc:Man:Gal in approximate molar ratios of 5.8:6.7:1.0. The molecular weight of the polysaccharide was determined to be approximately 1000 kDa by HPSEC analysis. Linkage analysis contained 3-Glcp, 3-Manp, terminal Glcp and terminal Manp, as well as a small proportion of 3- and 3,4-Galp, and 4,6-Manp residues. Based on analyses using FT-IR and ¹³C NMR spectrometers, most glycosidic bonds joining these sugar residues are of the α-type, and acetyl groups are apparently attached to the polymer chain at random.     

Predeployed secure key distribution mechanisms in sensor networks: current state-of-the-art and a new approach using time information

In this article we survey a number of predeployed secure key distribution (PSKD) schemes proposed in the technical literature. We also propose a new time-based PSKD (TPSKD), which operates under the assumption of loose time synchronization, and discuss the performance of the scheme. Since the TPSKD scheme uses time information, which would typically already be available in sensor nodes, the cost of the scheme?s implementation is low.     

面向企业信息化实现管理现代化

为适应社会信息化技术的发展，必须积极推行企业信息化，企业信息化引发管理革命，从而丰富了企业管理现代化的内容。本文论述了上述三方面的内部及演化关系，指出只有面向企业信息化，才能充分实现企业管理现代化。     

Highly ordered anodic alumina nanotemplate with about 14 nm diameter

A novel method for the fabrication of highly ordered nanopore arrays with very small diameter of 14 nm was demonstrated by using low-temperature anodization. Two-step anodization was carried out at 25 V, sulfuric acid concentration of 0.3 M, and electrolyte temperature of −15 °C. After anodization, a regular pore array with mean diameter of 14 nm and interpore distance of 65 nm was formed. The pore diameter and regular arrangement were confirmed by scanning electron microscopy (SEM) and fast Fourier transformation (FFT), respectively. The present results strongly suggest that the diameter of pores in a highly ordered alumina template can be reduced by lowering the anodization temperature.     

催化重整装置的扩能改造

介绍湛江东兴炼油厂的重整装置由200kt／a扩能至300kt／a中有关催化重整反应动力学模拟计算软件的应用、反应工艺技术的改造、装置标定的情况。结合装置实际情况，采用两段装填、两段混氢技术提升了装置的技术水平。标定结果表明，改造后的装置达到了预期目的。     

Effect of Y2O3, CeO2 on Sintering Properties of Si3N4 Ceramics

The effect of rare earth oxides Y203 or Ce02 on sintering properties of Si3N4 ceramics was studied and the mechanism of assisting action during sintering was analyzed. The results in dicate that the best sintering properties appear in Si3N4 ceramics with 5% Y203 or 8% CeO2. Secondary crystallites are formed at grain boundaries after heat treatment,which decreases the amount of glass phase and contributes to the improvement of high-temperature mechanical properties of silicon nitride.     

Experience in testing the Motif interface

The testing and quality assurance of the Motif 1.0 graphical user-interface software are described. The testing goals, which fell into three general categories (code coverage, defect-density, and defect-arrival rate), and a deliverable formal test suite are examined. The three phases of the testing process-evaluation, test development, and regression testing-and the tools used in testing are discussed     

Ozonation of CI Reactive Black 5 using rotating packed bed and stirred tank reactor

This study investigates the ozonation of CI Reactive Black 5 (RB5) by using the rotating packed bed (RPB) and completely stirred tank reactor (CSTR) as ozone contactors. The RPB, which provides high gravitational force by adjusting the rotational speed, was employed as a novel ozone contactor. The same ozone dosage was separately introduced into either the RPB or the CSTR for the investigation, while the experimental solution was continuously circulated within the apparatus consisting of the RPB and CSTR. The decolorization and mineralization efficiencies of RB5 in the course of ozonation are compared for these two methods. Moreover, the dissolved and off‐gas ozone concentrations were simultaneously monitored for the further analysis. As a result, the ozone mass transfer rate per unit volume of the RPB was significantly higher because of its higher mass transfer coefficient and gas–liquid concentration driving force. Furthermore, ozonation kinetics was found to be independent of the gravitational magnitude of an ozone gas–liquid contactor. Therefore, the results suggest employing RPBs as ozone‐contacting devices with the advantage of volume reduction. The experimental results, which can be used for further modeling of the ozonation process in the RPB, also show the requirement of correct design for the RPB. Consequently, the present study is useful for the understanding of practical application of RPBs. Copyright © 2004 Society of Chemical Industry     

Crystal growth of selected II–VI semiconducting alloys by directional solidification: Part I Ground-based experiments

A series of Hg_0.84Zn_0.16 Te crystal ingots have been grown from pseudobinary melts by the Bridgmam–Stockbarger type directional solidification using a Marshall Space Flight Center/Space Science Laboratory heat-pipe furnace and the ground control experiment laboratory furnace of the crystal growth furnace which was flown on the first United States Microgravity Mission. A number of translation rates and a series of hot- and cold-zone temperatures were employed to assess the influence of growth parameters on the crystal properties for the purpose of optimizing the in-flight growth conditions. This revised version was published online in November 2006 with corrections to the Cover Date.