浅谈提高信道效率的措施

提高信道的数据传输效率是人们不断追求的目标之一，也是衡量网络性能的标准之一，从几方面分析总结了为此而采取的各种措施。     

深孔薄壁件挤压模CAD系统

介绍了利用ActiveXAutomation技术，以VB为开发工具，并采用参数化绘图研究开发的深孔薄壁件挤压模CAD系统。     

Axisymmetric extrusion through adaptable dies—Part 1: Flexible velocity fields and power terms

An adaptable die is one that not only produces the correct geometrical shape, but also is designed through an adaptable method to impart other desirable properties to the product or process. In this first part of a series of papers, six kinematically admissible velocity fields are developed for use in upper bound models for axisymmetric extrusion through various dies, including extrusion through adaptable dies. Three base velocity fields are presented:

(1) assuming proportional angles in the deformation zone,

(2) assuming proportional areas in the deformation zone, or

(3) assuming proportional distances from the centerline in the deformation zone.

The base velocity is modified by an additional term comprised of two functions. One function allows extra flexibility in the radial direction, and the second function allows extra flexibility in the angular direction. There are two forms of the second function, which meet the required boundary conditions. The flexibility function in the radial direction is represented by a series of Legendre polynomials, which are orthogonal over the deformation region. The power terms derived for these velocity fields for use in upper bound models are also presented.Part 2 of this series compares the results obtained in upper bound models for the six velocity fields for a spherical extrusion die. In Part 3, the use of the best velocity field for extrusion through streamlined dies is developed to determine the adaptable die shape, which minimizes the required extrusion pressure. Additionally, the adaptable die shape is compared with results from Yang and Han for arbitrarily curved and streamlined dies.     

电信服务营销渠道转型的必要性

分析了电信企业服务营销渠道的特点、旧有的服务营销渠道模式和存在的问题以及今后电信业和市场等方面发展的新需求，对电信服务营销渠道转型的必要性进行了探讨和研究,同时提供了一个可供参考的服务营销渠道价值评估体系架构,从量化服务营销渠道对电信企业贡献价值的角度论述了服务营销渠道转型的必要性。     

Recovery retardation in equal channel angular pressed Al–Zr alloy during friction stir welding

The effect of Zr on reduction of hardness and microstructure in an FS weld of equal channel angular-pressed Al alloy was investigated. Zr addition to Al suppressed dynamic recovery in the thermomechanically affected zone and enabled retention of the high hardness of the ECA-pressed material throughout the weld.     

连续挤压法介绍

连续挤压法的特点是：挤压所需的压力是借助一个回转的摩擦轮来实现的。摩擦轮的轮缘上设有一个凹槽，其断面取决于原坯的断面（线材坯料）。本文将就这种工艺的设备和有关铝材生产阶段中的一些问题作一简介。     

移动运营商渠道管理模式及存在问题分析

渠道作为营销体系中的重要一环，对移动运营商的发展起着举足轻重的作用。随着国内移动市场竞争的加剧，营销渠道的竞争将成为移动运营商间竞争的焦点。目前，国内两大移动运营商在渠道管理上存在诸多问题，从而影响了其市场拓展。分析了移动选营商渠道管理存在的三个较为突出的问题，并提出了可行的解决方法，从而为移动运营商的渠道管理工作提供思路。     

Effects of annealing at high pressure on structure and mechanical properties of Al87Ni7Gd6 metallic glass

The effects of annealing and annealing with a superimposed pressure of 940 MPa on the primary crystallization behaviour of α-Al and the resulting micro-hardness have been studied for as-quenched Al₈₇Ni₇Gd₆ metallic glass. Isothermal annealing experiments were conducted for 30 min at 188 °C, 191 °C, and 205 °C in silicone oil maintained either at atmospheric pressure (i.e. 0.1 MPa) or at 940 MPa. XRD analyses detected the evolution of structure with annealing at 0.1 MPa, while specimens annealed with 940 MPa pressure exhibited sharper diffraction peaks than those annealed at 0.1 MPa. DSC measurements were conducted on the as-received amorphous ribbons as well as ribbons annealed at different temperatures at either 0.1. MPa or with 940 MPa superimposed pressure. Specimens annealed with 940 MPa pressure exhibited higher onset temperatures (i.e. T_x1) and temperatures for the first exothermic peak (i.e. T_p1) for primary crystallization. TEM measurements revealed an increase in the volume fraction of α-Al with increases in annealing temperature, while micro-hardness measurements revealed an increase in hardness with increasing amounts of α-Al. Specimens annealed with 940 MPa pressure exhibited further increases in both the volume fraction of α-Al and resulting micro-hardness.     

有芯工频炉酸性炉衬对生产欧元材料的影响

通过对有芯工频炉酸性炉衬生产欧元材料出现的问题进行分析，发现在使用有芯工频炉酸性耐火材料时，炉衬寿命大大缩短，并使铜液Si含量超标，造成材料报废。而炉衬材料换成中性耐火材料时，基本上控制了Si含量，达到了欧元材料标准，并使炉衬寿命大大提高。