UWB无线通信关键技术及应用分析

UWB是目前最理想的低功耗、高带宽短距离无线通信技术。文中通过研究UWB无线通信的关键技术,指出其性能优点及局限性,阐明了UWB技术在军用和民用方面的应用前景。     

Adsorption Study of Methane on Activated Meso-carbon Microbeads by Density Functional Theory

A combined method of density functional theory (DFT) and statistics integral equation (SIE) for the determination of the pore size distribution (PSD) is developed based on the experimental adsorption data of nitrogen on activated mesocarbon microbead (AMCMB) at 77K. The pores of AMCMB are described as slit-shaped with PSD.Based on the PSD, methane adsorption and phase behavior are studied by the DFT method. Both nitrogen and methane molecules are modeled as Lennard-Jones spherical molecules, and the well-known Steele‘s 10-4-3 potential is used to represent the interaction between the fluid molecule and the solid wall. In order to test the combined method and the PSD model, the Intelligent Gravimetric Analyzer (IGA-003) was used to measure the adsorption of methane on the AMCMB. The DFT results are in good agreement with the experimental data. Based on these facts,we predict the adsorption amount of methane, which can reach 32.3ω at 299K and 4 MPa. The results indicate that the AMCMBs are a good candidate for adsorptive storage of methane and natural gas. In addition, the capillary condensation and hysteresis phenomenon of methane are also observed at 74.05K.     

网间移动号码携带业务受理测试方案介绍

介绍了网间移动号码携带业务受理流程测试方案,包括测试环境、测试内容以及测试方法和流程。     

网间移动号码携带现场试验的测试工作

在天津和海南进行的网间移动号码携带现场试验测试,包括受理流程测试和业务流程测试,以及每个测试阶段的准备工作、测试内容、测试环境。测试中出现一些典型问题,但绝大部分都及时得到解决。这些问题将来在全国测试中还可能出现。现在的现场测试会避免将来出现类似的问题,或者出现问题时能及时得到定位和解决。     

5G网络设备安全评测护航"新基建"

与4G移动通信技术主要实现人与人通信不同,5G以其高带宽、低时延和超高密度连接能力,将通信服务对象全面扩展至人与物、物与物,开启了万物互联的新时代.5G作为"新基建"的重要组成部分,在我国新时代的建设进程中,发挥着极为重要的作用.5G商用在给科技、经济等社会各领域带来深刻变革的同时,也给国家公共安全、网络安全以及数据安...     

VPN技术在军队网络建设中的应用

随着现代军队信息化建设步伐的不断加快,其负责多种信息传输任务的军网的地位也随之提高,因此军网中的信息安全显得越来越重要。并且多数的军事单位分布较为分散,无法分享上级机关的服务资源,单位之间也无法实现协同办公、资源共享。针对以上问题,在简述VPN技术的基础上,分析了军队专用网络的需求,给出了VPN技术应用于军网的具体方案,从而实现远程用户、分部网络以及友邻部队对内部网络资源的快速、有效、安全的访问。