Preparation of silver nanoparticle via active template under ultrasonic

1Introduction During the past several years,there has been a growing interest in the novel materials called nanomaterials that have a very high surface or interfacial area and exhibit dramatic changes in properties.Among them,metal nanoparticles have been…     

软土地基加固中的冲击碾压施工方法

本文依据有关规范和设计文件,结合浦东机场快递机坪、东货运区和西货机坪地基处理工程的实践,对如何保证冲击碾压的效果和提高冲击碾压施工的效率进行了研究和总结,对于软土地基加固中冲击碾压施工有一定的借鉴意义。     

超薄SiO2软击穿后I-V特性的饱和性质

利用电子速度饱和概念和比例差值方法（proportional difference operator, PDO）研究了超薄SiO2在第一次软击穿以后栅电流随着栅电压的变化所呈现的饱和性质. 实验证明了第一次软击穿以后栅电流随着栅电压变化的PDO谱峰位、峰高与电子在第一次软击穿通道中运动的饱和速度及饱和电流密度相关. 基于缺陷散射机制，得到的第一次软击穿通道的横截面积与文献报导的结果一致.     

微马达转子电镀导磁层的研究

本文推荐一种镀液，用于制作电磁型微电机转子坡莫合金导磁层，研究了该镀液的组成和工作条件对镀层成份和内应力的影响，表明该镀液具有可供选用的电流密度范围宽，允许较高Ｆｅ２－浓度和镀层内应力低等优点。     

Numerical simulations on performance of MEMS-based nozzles at moderate or low temperatures

Performance of microelectromechanical systems (MEMS)-based nozzles at moderate and low temperatures is numerically analyzed using the direct simulation Monte Carlo method. Considering the intermolecular attractive potential caused by low temperature, the generalized soft sphere collision model is introduced. The Larsen–Borgnakke model for the generalized sphere model is used to model the energy exchange between the translational and internal modes. The results for nozzle flows at an initial temperature of 300 K show that the temperature behind the throat is quite low and the intermolecular attractive potential cannot be ignored. Different working conditions in two-dimensional (2D) nozzles are simulated using the present method, including exit pressure, inlet pressure, initial temperature, nozzle geometry, and gas species. The effects on the nozzle performance are analyzed. Simulations on flows in a three-dimensional (3D) low aspect ratio flat nozzle show that the increased surface-to-volume ratio, which leads to high viscosity dissipation, causes a much lower flow characteristic and performance comparing with the 2D case.     

软测量模型自动生成系统的研究与开发

设计并开发出一套基于Matlab和VB的软测量建模生成系统。该系统的特点在于能提供多种选择变量和数据处理的方法;集成了多种多元回归神经网络等软测量建模方法及其相互结合的应用,这种结构使得用户能够在各种方法之间比较选择,从而最终和到一个合适的软洲量模型。改变了目前国内外一些软测量软件包只侧重于某种特定的建模方法的状况。同时系统采用了"提前停止"方法,克服一些软测量软件包所建模型的拟合精度高而推广能力不佳的缺点。实际建模应用表明,该系统算法简单、操作灵活,具有良好的人机交互和较高的执行效率。     

Behavior of a nonconformal mixture via computer simulation

A binary 50% mixture of soft spheres is studied via nonequilibrium molecular dynamics, and the equilibrium and nonequilibrium radial distribution functions for a nonconformal mixture with a mass ratio of 10 and a size ratio of about 2 are examined. This model system is related to the real methane/decane mixture, and it is shown that apparently anomalous properties of this mixture, especially the viscosity, could perhaps be understood in terms of the local or ambient mole fraction. In addition, the postulates of the Van der Waals one fluid conformal solution theory are discussed, and a mixing rule for the mass is derived.     

Adaptation of CDMA Soft Handoff Thresholds Using Fuzzy Inference System

This paper proposes a new procedure to adjust soft handoff thresholds dynamically by using fuzzy inference system. This algorithm is compared with IS-95A and IS-95B/cdma2000 soft handoffs. The aims are to increase the thresholds at high traffic loads in order to release the traffic channel for supporting more carried traffic, and to decrease the thresholds at low traffic loads in order to give high quality of traffic channel. The inputs of the proposed algorithm are the number of remaining channels of each base station and the number of active pilots in active set of each mobile station. The output is the new soft handoff thresholds. In the fuzzy inference module, the triangular membership function, the max-min composition, and the weighted average formula defuzzification are selected. By comparison of all performance indicators among three algorithms, soft handoff using fuzzy inference tends to give higher performance than those of IS-95A and IS-95B/cdma2000 soft handoffs at high traffic loads and at lower soft handoff thresholds while the quality of traffic channel is still acceptable. Moreover, the wider soft handoff window size of the proposed algorithm gives high carried traffic and low blocking probability but lower quality of traffic channels. In addition, the adaptive soft handoff window size can give lower blocking probability while still keep acceptable quality of traffic channels.     

直接法制取低功耗软磁铁氧体扩大试验研究

以铁屑、软锰矿和锌烟灰为原料,进行了10kg／次规模的直接法制取低功耗软磁共沉粉的实验室扩大试验。试验结果表明,共沉粉杂质元素含量低,配比准确,活性好。以本法制备的共沉粉为原料进行的单槽和多槽混合共沉粉的铁氧体工艺试验结果表明,由“直接法”所得共沉淀粉,经铁氧体工艺制备的锰锌软磁铁氧体产品的质量完全达到日本TDK公司的PC30、接近PC40指标,而且所有磁性能指标均超过国内某公司同类产品。