高速互连中信号完整性测试单元分析

介绍了高速互连中的信号完整性故障,主要探讨了由NMOS和PMOS管组成的内建高速互连检测单元,该单元用于对高速互连中的信号完整性故障进行测试。主要对已提出的2种故障检测单元进行了对比,分析了它们在信号完整性故障测试方面的不同特点,并用Hspice在有无噪声情况下进行了仿真,在理论分析和仿真结果方面显示了良好的一致性。     

基于重叠盒覆盖算法的节点重要度评估

由于单一的节点评估方法存在不足,在融合复杂网络的局部特征以及全局特征前提下,提出了一种基于重叠盒覆盖算法的节点重要度评估方法.该方法利用重叠中心性对网络中的节点进行重要度排序,并且与其他不同中心性方法在复杂网络数据集中的节点排序方法进行比较;利用susceptible-infected (SI)模型模拟不同中心性方法前10个节点的传播能力,在此基础上以肯德尔系数进行比较,肯德尔系数越大表明相关性越高.实验结果表明,与其他中心性方法相比,重叠中心性得到的初始节点集合的累积平均感染能力高于其他中心性方法,并且与SI模型具有较高的相关性,该方法对于节点重要度评估是有效并且可行的.     

Changes in the International System of Units proposed in recommendation E1 (2007) of the consultative committee on electricity and magnetism

Changes in the definitions of the technical units and units of electromagnetism in the International System of Units which may be adopted if Recommendation E1 (2007) is approved are discussed. It is shown that the verbal statement of the definition of the kilogram may be radically simplified if the division of units into fundamental and derived units is discarded in the new International System of Units. __________ Translated from Izmeritel’naya Tekhnika, No. 8, pp. 69–71, August, 2007.     

基于数据传送带协议的DVB-C数据广播系统计与实现

在深入研究DVB数据广播协议中的数据传送带协议的基础上，提出了一种在有线电视网络中传送数据广播业务警方案，它可在DVB—C单项信道中模拟实现用户和前端的双向交互，实现了在MPEG-2传输流中同时传输广播数据和数字音视频。     

激光/微波光电导衰减技术研究半绝缘GaAs复合寿命的分布

采用非接触式激光／微波光电导衰减技术（ＬＭＰＣＤ）对Φ５０．８ｍｍ双面抛光的半绝缘ＧａＡｓ晶片的复合寿命进行了无损伤检测，得到了有效载流子寿命沿晶片直径的径向分布曲线。结果表明，复合寿命为几百纳秒，在径向呈“Ｍ”型分布，和半绝缘ＧａＡｓ晶片中ＥＰＤ的“Ｗ”型分布相反。在考虑了位错密度和掺杂浓度对寿命的影响的基础上，对ＧａＡｓ晶片的寿命进行了讨论。     

地面数字电视机顶盒PSI/SI信息的接收与管理

介绍了节目特定信息和业务信息(PSI/SI)的组成和作用,对与地面数字电视机顶盒接收和管理PSI/SI信息过程相关的解复用模块和节目数据库模块作重点阐述,分析基于STi5105芯片的解复用原理,描述了节目数据库模块与解复用、用户操作模块之间的交互关系。     

数字视频广播服务信息的存储方案设计

随着数字电视的不断发展,接收机对服务信息的支持显得越来越重要。首先分析了MPEG-2的PSI与数字视频广播的服务信息,提出了一种服务信息的存储方案。该方案可以实现在实时多任务环境下对大量数据的及时存储、查找、提取与更新。此外,由于实现了PSI与服务信息之间的数据共享与混合存储,减小了对硬件资源的要求。     

New Assignment of Mass Values and Uncertainties to NIST Working Standards

For some time it had been suspected that values assigned to NIST working standards of mass were some 0.17 mg/kg larger than mass values based on artifacts representing mass in the International System of Units (SI). This relatively small offset, now confirmed, has had minimal scientific or technological significance. The discrepancy was removed on January 1, 1990. We document the history of the discrepancy, the studies which allow its removal, and the methods in place to limit its effect and prevent its recurrence. For routine calibrations, we believe that our working standards now have a long-term stability of 0.033 mg/kg (3σ) with respect to the national prototype kilograms of the United States. We provisionally admit an additional uncertainty of 0.09 mg/kg (3σ), systematic to all NIST mass measurements, which represents the possible offset of our primary standards from standards maintained by the Bureau International des Poids et Mesures (BIPM). This systematic uncertainty may be significantly reduced after analysis of results from the 3rd verification of national prototype kilograms, which is now underway.     

秦山核电三期工程厂坪前沿可能最大台风浪计算

利用有关文献提供的可能最大台风风场，采用文圣常等提出的混合型海浪数值模式计算了厂址外海域可能最大台风浪，再经近岸折绕射计算得出了厂坪关沿设计波要素，并对计算结果做了分析。     

Investigation of autoignition of propane and<Emphasis Type="Italic">n</Emphasis>-butane blends using a rapid compression machine

The effects of pressure and temperature on the autoignition of propane andn-butane blends were investigated using a rapid compression machine (RCM), which is widely used to examine the autoignition characteristics. The RCM was designed to be capable of varying the compression ratio between 5 and 20 and minimize the vortex formation on the cylinder wall using a wedge-shaped crevice. The initial temperature and pressure of the compressed gas were varied in range of 720-900 K and 1.6-1.8 MPa, respectively, by adjusting the ratio of the specific heat of the mixture by altering the ratio of the non-reactive components (N₂, Ar) under a constant effective equivalence ratio (ø_f=l.0). The gas temperature after the compression stroke could be obtained from the measured time-pressure record. The results showed a two-stage ignition delay and a Negative Temperature Coefficient (NTC) behavior which were the unique characteristic of the alkane series fuels. As the propane concentration in the blend were increased from 20% and 40% propane, the autoignition delay time increased by approximately 41% and 55% at 750 K. Numerical reduced kinetic modeling was performed using the Shell model, which introduced some important chemical ideas, represented by the generic species. Several rate coefficients were calibrated based on the experimental results to establish an autoignition model of the propane andn-butane blends. These coefficients can be used to predict the autoignition characteristics in LPG fueled SI engines.