Model experiment on anti-deformation performance of a self-supporting transmission tower in a subsidence area

A large number of high-voltage power transmission towers have recently been constructed in mining areas prone to subsidence.In order to ensure the safety of the transmission towers and the safe operati...     

新乡市旅游产业转型升级的对策研究

实现旅游产业的转型升级是新乡市旅游业发展到一定阶段的必然选择。文章从新乡旅游产业转型升级的背景入手,对制约新乡市旅游产业转型升级的因素进行了深入的分析论证,并提出了相关的对策和建议。     

Energy flux characteristics of seismic waves at the interface between soil layers with different saturations

Based on the multiphase poroelasticity theory describing the propagation of waves in the unsaturated fluid-saturated porous medium, the reflection and transmission coefficients of the seismic waves at the interface between soil layers with different saturations are obtained. Our unsaturated model consists of a deformable skeleton in which two compressible and viscous fluids (i.e., water and gas) flow in the interstices. Three compressional waves (i.e., P1, P2, and P3 waves) and one shear (i.e., S wave) wave exist in the unsaturated soils. The expressions for the energy ratios of the various reflected and transmitted waves at the interface during the transmission and reflection processes are presented in explicit forms accordingly. At last, numerical computations are performed and the results obtained are respectively depicted graphically. The variation of the energy ratios with the incident angle, wave frequency and saturation degrees of the upper and lower soil layers is illustrated in detail. The calculation results show that the allocation of incident seismic waves at the interface is influenced not only by the angle and frequency of the incident seismic waves, but also by the saturations of the upper and lower soil layers. It is also verified that, at the interface, the sum of energy ratios of the reflected and transmitted waves is approximately equal to unity as was expected. This study is of importance to several fields such as geotechnical engineering, seismology, and geophysics.     

回归传统价值:《了不起的盖茨比》的救赎之路

《了不起的盖茨比》生动地描述了二十世纪二十时代的美国社会丰裕物质生活与精神荒原的冲突。美国梦的幻灭、道德和宗教信仰体系的坍塌引发了菲茨杰拉德对美国精神和传统价值观的思索,呼吁回归传统价值观,重塑道德体系。     

灰乳的陈化

<正> 明胶生产要用石灰乳浸泡处理骨素。那么,石灰乳应该如何配制才能充分得到利用,这是笔者关注的一个问题。为此我们做了下面的实验。     

80 kt/a硫铁矿制酸扩建装置采用的新技术措施

针对采用水洗净化工艺的某80kt/a硫铁矿制酸装置的扩建设计，介绍了其中主要改扩建工段及设备采用的新技术措施，设计中对原料工段、沸腾炉、文氏管、泡沫塔、转化器、换热器等进行了改进，满足了厂方两期建设产量不同的要求。     

超细片状铝粉和铝银浆的制备

超细鳞片状铝粉和铝银浆由于其特殊的二维平面结构，具有良好的遮盖力、显著的屏蔽效应、光学反射能力；超细鳞片状铝粉和铝银浆颜料的制备方法很多，本文采用机械化学法制备超细鳞片状铝粉和铝银浆。     

热连轧中AGC控制系统的研究与应用

本文重点介绍莱钢1500mm热连轧机中液压AGC的控制性能及其实现方式。     

Shift-full-rank matrices and applications in space-time trellis codes for relay networks with asynchronous cooperative diversity

To achieve full cooperative diversity in a relay network, most of the existing space-time coding schemes require the synchronization between terminals. A family of space-time trellis codes that achieve full cooperative diversity order without the assumption of synchronization has been recently proposed. The family is based on the stack construction by Hammons and El Gamal and its generalizations by Lu and Kumar. It has been shown that the construction of such a family is equivalent to the construction of binary matrices that have full row rank no matter how their rows are shifted, where a row corresponds to a terminal (or transmit antenna) and its length corresponds to the memory size of the trellis code on that terminal. We call such matrices as shift-full-rank (SFR) matrices. A family of SFR matrices has been also constructed, but the memory sizes of the corresponding space-time trellis codes (the number of columns of SFR matrices) grow exponentially in terms of the number of terminals (the number of rows of SFR matrices), which may cause a high decoding complexity when the number of terminals is not small. In this paper, we systematically study and construct SFR matrices of any sizes for any number of terminals. Furthermore, we construct shortest (square) SFR (SSFR) matrices that correspond to space-time trellis codes with the smallest memory sizes and asynchronous full cooperative diversity. We also present some simulation results to illustrate the performances of the space-time trellis codes associated with SFR matrices in asynchronous cooperative communications.     

基于被动测试的web应用测量

提出一种新的基于被动测试的web应用测量方法,以便准确、快速的获取应用特征与状态信息。设计了web应用测量协议WMP,并对基于该协议的测量系统进行了设计与实现。实验表明该系统能够准确快速地对待测的应用协议交互部分进行测量,为应用管理提供丰富有效的信息。