南官河大桥系梁浇筑支架搭设施工优化

根据南官河大桥工程本身的特点及现场的具体情况，选择在河中打钢管群桩并在上面架设贝雷架钢桁架梁作为模板支撑支架的方法，取得了施工方便、安全、经济的效果。     

磁场中含氯化石蜡润滑油的摩擦学性能研究

在有磁场和无磁场的条件下,用改进过的四球试验机考察了不同载荷下含氯化石蜡润滑油的摩擦学特性。在磁场的作用下,含氯化石蜡润滑油中钢球的磨斑直径均有所降低,说明含氯化石蜡润滑油的抗磨性能得到改善。磁场有利于摩擦副表面吸附氯化铁膜,提高了含氯化石蜡润滑介质的抗磨性能。但磁场会导致更严重的腐蚀。     

Effect of trace Na additions on the hydriding kinetics of hypo-eutectic Mg–Ni alloys

Mg–Ni alloys are among the most promising candidates for solid-state hydrogen storage systems. This paper reveals the effect of Na doping in accelerating initial hydrogen uptake in Mg–Ni alloys using in-situ Synchrotron X-ray powder diffraction. A minimum concentration of approximately 0.2 wt.% Na must be achieved for the alloys to show reasonably fast hydriding kinetics. Surface analysis shows that a Na-modified Mg–Ni surface facilitates the chemisorption and dissociation of hydrogen molecules in the early stage of hydriding as evidenced by a rapid formation of the saturated hydrogen solid solution Mg₂NiH_0.3 from the original Mg₂Ni. The subsequent hydrogen absorption is based on a mechanism of nucleation and growth of MgH₂ where a high density of dislocations develops ahead of the growing hydride-metal interface.     

Secondary Coincidence Site Lattice Model for Truncated Triangular β-Mg2Sn Precipitates in a Mg-Sn-Based Alloy

This article presents a model of a secondary coincidence site lattice (CSL^ΙΙ). It is applied to interpret a truncated triangular morphology of β-Mg₂Sn precipitates in an Mg-Sn-based alloy. With a slight long-range strain being accommodated elastically, the distribution of good matching sites (GMS) on interfaces between the β-Mg₂Sn precipitates and α-Mg matrix exhibits double periodicity. One is within GMS clusters, and the other is carried by the constrained-CSL^ΙΙ (CCSL^ΙΙ) points at the centers of the GMS clusters. The calculated results fully agree with the experimental results, including the irrational orientation relationship, the habit plane, and the irrational side facets. The preferred state of the interfaces, the preferred ledge height, and the preferred Burgers vectors of secondary dislocations have been discussed.     

菊粉酶及其制备低聚果糖研究进展

低聚果糖作为一种功能性低聚糖,具有增殖肠道有益菌等独特的生理功能,近年来备受关注。文章主要从菊粉提取、微生物产菊粉酶、酶法制备低聚果糖及其下游分离纯化等方面,综述了近年来菊粉酶及其制备低聚果糖的国内外研究进展与现状。     

浅谈课堂教学中的德育渗透

德育教育是全体教师的共同职责,本文从课堂德育教育缺失的原因分析出发,紧紧抓住课堂德育渗透这一重要渠道,阐述了德育渗透的重要性,并结合实际提出了课堂教学中德育渗透的基本途径。     

OMA DM‐based remote software fault management for mobile devices

Mobile devices (e.g. mobile handsets or PDAs) have gained much functionality and intelligence with the growth of mobile network technologies and the increased use of mobile services. As a consequence, mobile devices have become more complex and many related problems have occurred. Specifically, sudden rebooting and freezing problems caused by software faults decrease the availability of the mobile device and cause inconvenience to end‐users. To solve such problems, academia and industry have focused on Open Mobile Alliance (OMA) Device Management (DM); this method is the international de facto standard for mobile device management. In this paper, we propose a software fault management method to remotely determine and correct problems of mobile devices based on OMA DM. We present a definition of management objects and a method to collect them from mobile devices using the OMA DM protocol. We also present a method for debugging and correcting software faults using the collected information. Finally, we present a prototype implementation and performance evaluation to validate our proposed method. Results of the performance evaluation show that our proposed method is efficient and scalable in regard to network traffic overhead and response time. Copyright © 2009 John Wiley & Sons, Ltd.     

Current–Voltage Characteristics in Individual Polypyrrole Nanotube, Poly(3,4-ethylenedioxythiophene) Nanowire, Polyaniline Nanotube, and CdS Nanorope

In this paper, we focus on current–voltage (I–V) characteristics in several kinds of quasi-one-dimensional (quasi-1D) nanofibers to investigate their electronic transport properties covering a wide temperature range from 300 down to 2 K. Since the complex structures composed of ordered conductive regions in series with disordered barriers in conducting polymer nanotubes/wires and CdS nanowires, all measured nonlinear I–V characteristics show temperature and field-dependent features and are well fitted to the extended fluctuation-induced tunneling and thermal excitation model (Kaiser expression). However, we find that there are surprisingly similar deviations emerged between the I–V data and fitting curves at the low bias voltages and low temperatures, which can be possibly ascribed to the electron–electron interaction in such quasi-1D systems with inhomogeneous nanostructures.     

Study on the optimal hydropower generation of Zhelin reservoir

Zhelin reservoir, a multi-purpose reservoir designed mainly for hydropower generation, is located in Xiushui watershed in Jiangxi Province, China. As the rainfall has a decreasing trend in recent years, the reservoir storage capacity cannot be fully filled and the original operation rule can no longer fulfill the desired target for power production. In order to ensure the dam safety and produce more economic benefits from hydropower generation, the original operation rule of the reservoir needs to be evaluated for possible improvement to yield optimal benefits. In this study three optimization algorithms including progressive optimization algorithm (POA), particle swarm optimization (PSO) and genetic algorithm (GA) are applied. According to a long discharge data series, the minimization of water consumption rate is chosen as the objective function, along with several physical and operational constraints. After comparing the results of the three methods, POA is found more suitable for Zhelin reservoir. Sensitivity of the optimization algorithms is also analyzed, of which, the step size of water level of the reservoir for POA, the initial population sizes for PSO and GA are also explored to search for the most suitable parameters. The investigation further reveals that step size 0.01 m, population size 50 and 30 are the best choice for POA, PSO and GA, respectively.