Effect of the geometric shapes of specimens on impact tensile tests

The geometric shapes of specimens are important in impact tensile tests because geometric shapes determine the stress states of the specimens, and precise geometric shapes can obtain proper material properties without non-material factors. The aim of this study was to investigate the 1D form of the stress by changing the length-to-diameter （L/D） ratios of specimens. The experiments were carried out on a split Hopkinson tensile bar （SHTB）-rotating disk indirect bar-bar tensile impact apparatus. The L/D ratios of the LY12CZ specimens used in the test ranged from 1 to 5. Results show that the specimens can be used to obtain exact parameters of materials under the proposed conditions when the L/D ratio is greater than 2. This is because the longer length will reduce or eliminate the effects of the interfaces.     

Tool wear criterion,tool life,and surface roughness during high-speed end milling Ti-6Al-4V alloy

The objective of the present research is to investigate the relationship among tool wear, surface topography, and surface roughness when high-speed end milling Ti-6Al-4V alloy, and also to define an optimal flank wear criterion for the cutting tool to integrate tool life and the surface roughness requirements of the finish milling process. An annealed Ti-6Al-4V alloy was selected as the workpiece material, undergoing end milling with uncoated carbide inserts. The flank wear of the insert was observed and measured with the toolmaker＇s microscope. To examine machined surfaces, 3D surface topography was provided by the white light interferometer, and the arithmetical mean roughness （Ra） was calculated with the WYKO Vision32 software. The flank wear increases with cutting time, and the maximal flank wear is set as the flank wear criterion. As the cutting process progresses, tool wear is the predominant factor affecting the variation of surface roughness. According to the plots for the tool wear propagation and surface roughness variation, an optimal flank wear criterion can be defined which integrates the tool life and the surface roughness requirements for the finish milling process.     

国际标准书号与图书条形码释义及其转换算法*

正式出版的图书封底所印制的图书条形码与图书的国际标准书号（ISBN）有着密切的关系。了解他们的含义，明确他们之间的转换关系，对于图书馆自动化管理系统（特别是采访查重子系统）的设计应用和出版社图书条形码的编号问题有着重要的作用。文章介绍了两者的含义及其之间的转换算法。     

数学研究中的辩证法

数学中蕴含着丰富的哲理，数学不仅给我们以知识和能力，同时也给我们人生以乐趣和启迪。     

根据CMM实施软件过程改进

软件过程控制是影响软件产品质量的关键要素之一。在软件过程中要借助有效的工具实施CMM，实现软件过程的改进。在实施过程中要遵循自低向上、循序渐进、测试先行的策略。     

行政执法监督体系的构建与完善

行政执法监督是依法行政的重要保障、我国行政执法监督虽然很大程度地保障了依法行政,但行政执法监督体系不够完善,还存在不少问题.文章分析了行政执法监督体系的构成及现存问题,并在此基础上提出了行政执法监督体系的构建和完善重点.     

高速加工工艺与数控编程研究

本文对高速加工中刀具选择、加工工艺、工艺参数和数控编程均做了详细的论述，并对高速加工提出了较为完整、可行的加工思路。     

基于C/S结构的上机管理信息系统实现方法

本文以上机管理信息系统的开发为背景,介绍基于Ｃ/Ｓ结构的管理信息系统的实现方法。     

Compressive Strength of Hydrostatic-Stress-Sensitive Materials at High Strain-Rates

Many engineering materials demonstrate dynamic enhancement of their compressive strength with the increase of strain-rate, which have been included in material models to improve the reliability of numerical simulations of the material and structural responses under impact and blast loads. The strain-rate effects on the dynamic compressive strength of a range of engineering materials which behave in hydrostatic-stress-sensitive manner were investigated. It is concluded that the dynamic enhancement of the compressive strength of a hydrostatic-stress-sensitive material may include inertia-induced lateral confinement effects, which, as a non-strain-rate factor, may greatly enhance the compressive strength of these materials. Some empirical formulae based on the dynamic stress-strain measurements over-predict the strain-rate effects on the compressive strength of these hydrostatic-stress-sensitive materials, and thus may over-estimate the structural resistance to impact and blast loads, leading to non-conservative design of protective structures.     

哲学视野下中国公共行政的理性思考——价值理性与工具理性的冲突与调适

本文通过探讨中西方在公共行政领域内价值理性与工具理性取向的分野,论述了公共行政中国本土化过程中价值理性所推荐的正义、信念、道德与工具理性所推荐的效率、责任,以及法律在公共行政中的冲突与表现。提出了公共行政价值理性的重塑,公共行政工具理性归位的建议,通过公共行政道德化的途径达到解决中国公共行政中价值理性与工具理性的冲突,实现二者的调适整合。