条件接收系统中解扰器的设计与实现

介绍数字视频广播（Digital Video Broadcasting，DVB）条件接收系统的系统结构，详细分析了条件接收系统的工作原理，并给出条件接收系统的解扰器工作流程及实现方案。     

Observation and computer simulation of multicomponent chemical short-range order （MCSRO） for the bulk metallic glasses

The atomic configuration of chemical short-range order (CSRO) for the Zr-base metallic glasses was investigated by using nano-diffraction and high resolution transmission electronic microscopy (HRTEM) technology with a beam size of 0.5 rim. It is illustrated that the pattern of atomic configuration of CSRO might have various compound counterparts because of the chemical interaction of bonding atoms. Some atomic configuration of MCSRO is similar to the icosahedral structure with 10-fold symmetry of very weak spots. In deed, the nano-beam technology could clearly detect the evolution of atomic configuration in nanometer scale during the transformation from the metallic melt to the primary crystallization. The local atomic configuration of CSRO is also investigated by molecular dynamics simulation (MD) for the Zr2Ni compound in a wider temperature range. The CSRO in the melt could be pictorially demonstrated as distorted coordination polyhedron of the compound structure and/or the structure similar to cubo-octahedron analogs. The MD simulation illustrates that the atomic packing of long-range order disappears just above the melting point, but the chemical interaction of bonding atoms still exists that leads to form the various CSRO with the atomic configuration similar to stable or metastable unit cell of Zr2Ni compound. The icosahedral polyhedron became more abundance as the overheating temperature was raised.     

工业废磷酸抛光液萃取回收制取工业级磷酸的研究

工业废磷酸洗液中磷酸含量平均为500 g/L,并含有一定量的Cu2+、Fe3+、Al3+、Zn2+、SO42-、NO3-、CH3COO-等杂质离子,加碱中和、沉淀等处理后排放会造成磷资源的浪费。通过浓缩、萃取、洗涤、反萃取、一次蒸发、碳酸钡脱硫、活性炭脱色、二次蒸发等系列处理后,杂质的含量能完全降低到工业磷酸的要求,磷酸的浓度和色度都符合国家工业磷酸标准。     

水在高温硫化硅橡胶中的扩散特性研究

水分侵入是造成复合绝缘子高温硫化硅橡胶伞裙、护套材料老化的主要因素之一。为了获得能够准确描述水分子在硅橡胶中扩散的扩散模型和扩散特性,使用固体核磁共振(nuclear magnetic resonance,NMR)技术,分析了水分子在硅橡胶中的存在状态;并通过称重法试验,获得了水分子在硅橡胶中扩散时硅橡胶的增重曲线。研究表明,水分子在硅橡胶中存在"自由态"和"结合态"两种不同的状态。固体核磁共振和称重法的试验结果都表明,水分子在硅橡胶中的扩散过程符合Langmuir扩散模型,而不符合经典的Fick扩散模型。同时研究了水分子扩散过程的影响因素,结果发现:自由态水分子的含量随温度的升高而增加,结合态水分子的含量随温度的升高而降低,且温度对扩散系数的影响符合经典的Arrhenius方程;硅橡胶中的氢氧化铝(ATH)填料含量的增加会导致结合态水分子含量的增加,但ATH含量对自由态水分子含量的影响不显著。     

煤矿开采沉陷移动变形预测

为了预测评价开采沉陷对矿区环境的影响,正确选择环境保护措施,必须对开采沉陷引起的地表下沉、倾斜、曲率、水平变形等移动变形值、地表移动持续的时间和最大下沉速度、开采沉陷的范围、冒落带和导水裂隙带的高度以及采动过程中地表移动变形等进行预测,本文将介绍几种预测方法.     

基于双CPU的CAN总线智能控制节点的设计

介绍了一种基于CAN总线、采用双CPU结构的智能控制节点的设计,说明了该智能控制节点的工作原理并详细阐述了其所具备的功能、硬件组成和软件实现.此控制节点结构新颖,采用了当前比较先进的技术.实验证明由该类节点组成的控制系统结构简单,实时性好,准确,可靠性高.     

谈有线数字电视机顶盒检测方法

本文主要讨论如何制定有线数字电视机顶盒的检测方案,包括检测环境的搭建以及在不同阶段的检测规则。     

TBP/煤油热解焚烧装置的改进及冷试验证

国内低放废液磷酸三丁酯/煤油(TBP/煤油)热解焚烧处理设施的主要核心设备——热解炉是从国外某公司引进的,在工程系统冷调试过程发生了热解炉的搅拌桨卡死和高温气体过滤器严重堵塞的情况,导致系统不能稳定运行。经对热解炉检查,发现国外引进热解炉存在设计和制造缺陷,不能满足系统稳定运行。通过系统分析研究,国内自主设计一套磁力驱动搅拌桨转动装置和烧结金属高温气体过滤器,在后续调试过程中取得了比国外某公司原设计更好的运行效果,使得我国TBP-煤油热解处理设施顺利调试成功。     

A comparison of coagulation and gelation on the structures and stabilization behaviors of polyacrylonitrile fibers

The fiber spinning methods determine the formation of the physical structures of polyacrylonitrile (PAN) fibers which further affect stabilization reactions and the mechanical performances of the resultant carbon fibers. In this study, PAN fibers were prepared by both dry-jet gel spinning (g-PAN) and dry-jet wet spinning (w-PAN), and their stabilization behaviors were compared. While the stabilized w-PAN fibers show sheath-core structures, the stabilized g-PAN fibers exhibit relatively uniform stabilized structures along the radial direction. Additionally, the stabilization reactions of g-PAN fibers occur faster than that of w-PAN fibers, and the cyclization, oxidation, and crosslinking reaction activation energies of g-PAN fibers are lower than that of w-PAN fibers, respectively. Moreover, the carbon yield of g-PAN is higher than that of w-PAN fibers. We believe that above changes are possibly ascribed to the formation of different PAN sheath structures and oriented chain structures during dry-jet wet spinning and dry-jet gel spinning. It is concluded that gel spinning could significantly reduce the sheath-core difference of PAN fibers and the stabilized fibers as compared with wet spinning, which leads to a faster stabilization and more uniform stabilized structures. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 137, 48671.