电子商务中的安全技术

随着我国加入WTO和Internet的飞速发展，电子商务已成为一个新的热点，其交易安全成为当前电子商务进程中关键性的因素。本介绍了电子商务的安全要求和使用的基本安全技术，对RSA加密技术、SET协议及混合型防火墙技术进行了分析。     

同三国道主干线粤境开阳高速公路路面下面层SUPERPAVE配合比设计

结合同三国道主干道粤境开阳高速公路K170 000-K205 400的下面层Superpave配合比设计。介绍Superpave的应用情况．     

8-碘-9-四氢吡喃-2-基-9H-嘌呤的合成

以 9-四氢吡喃 - 2 -基 - 9H-嘌呤、丁基锂和 I2 等为主要原料 ,四氢呋喃 ( THF)为溶剂 ,合成了 8-碘 - 9-四氢吡喃 - 2 -基 - 9H-嘌呤。考察了主要反应条件对反应的影响 ,确定了较佳工艺条件 :反应温度 - 78℃ ,n( 9-四氢吡喃 - 2 -基 - 9H-嘌呤 )∶ n(丁基锂 )∶ n(碘 ) =1 .0∶ 1 .5∶ 1 .5 ,反应时间 2 h。此条件下 ,产物收率 >90 %。同时 ,采用 1H- NMR、13C-NMR和 MS对产物结构进行了表征     

基于多相滤波器组的语音基频检测方法

基于多相滤波器组的语音基频检测方法，运用多相滤波器组分解语音信号频谱，然后利用声带震动的能量准周期性在各子带进行峰值搜索，并综合这些子带的搜索结果计算基音周期，最后根据先验知识以及一种新的清浊音判定方法对结果进行校正。基于标准TIMIT语料库子集的实验结果证明了此方法的有效性。     

Two-group interfacial area transport in vertical air-water flow: I. Mechanistic model

The prediction of the dynamical evolution of interfacial area concentration is one of the most challenging tasks in two-fluid model application. This paper is focused on developing theoretical models for interfacial area source and sink terms for a two-group interfacial area transport equation. Mechanistic models of major fluid particle interaction phenomena involving two bubble groups are proposed, including the shearing-off of small bubbles from slug/cap bubbles, the wake entrainment of spherical/distorted bubble group into slug/cap bubble group, the wake acceleration and coalescence between slug/cap bubbles, and the breakup of slug/cap bubbles due to turbulent eddy impacts. The existing one-group interaction terms are extended in considering the generation of cap bubbles, as well as different parametric dependences when these terms are applied to the slug flow regime. The complete set of modeling equations is closed and continuously covers the bubbly flow, slug flow, and churn-turbulent flow regimes. Prediction of the interfacial area concentration evolution using a one-dimensional two-group transport equation and evaluation with experimental results are described in a companion paper.     

基于遗传算法的多级有限能力生产计划

近年来很多学者研究了提前/拖期惩罚下的准时生产模型,但都局限于单件生产模式,关于多级装配情形的研究则很少,且均将加工能力视为常数.本文提出多级有限能力的准时化生产计划模型,并将加工能力视为变化的,最后采用遗传算法求解,计算结果证明了模型的有效性.     

软件DSM系统的重放

软件DSM系统的并行调试环境已经成为制约其广泛应用的一个重要因素，重放方法使得用户能用循环调试技术来调试具有执行不确定性的软件DSM程序，本文定义了软件DSM程序执行的happen-before-1关系，并依据其提出一种在软件DMS系统JIAJIA上实现重放的方法，实际应用测试表明，该方法产生很小的空间和时间开销。     

Development of centrifugal casting high speed steel rolls

The present study aims at developing the high speed steel (HSS) as roll materials to replace the traditional roll materials such as the alloy cast iron and powder metallurgical (PM) hard alloy. The HSS roll billet was formed by centrifugal casting, and the billet was rough machined after soften annealing heat treatment, then it was quenched and tempered to get suitable hardness and toughness. After that the HSS roll was finish machined to the final dimension of φ285 mm in the outer diameter, φ160 mm in the inner diameter and 120 mm in width and its surface hardness was tested. Finally the HSS roll was used in high speed wire rod mill. The test results show that a high and homogeneous hardness can obtain on the work surface of HSS rolls, the surface hardness is 63-65HRC and its variation is smaller than 2HRC. The impact toughness of this kind of HSS is about 16 J/cm2. The results of on-line service investigation in high speed wire rod mill indicate that the HSS rolls have excellent wear resistance, the     

在Labview选择结构中实现非全部子框架对输出赋值

本文介绍了在Labview环境下，非全部子框架对输出赋值的三种方法，解决了与Labview要求的每个子框架都必须赋值的矛盾，并给出具体范例。     

数字视频监控系统及其应用

介绍了视频监控的发展现状 ,分析了模拟视频监控的缺点 ,对数字视频监控的结构和特点进行了分析和比较 ,并讨论了数字视频监控的发展趋势。