CATV系统传输线传输特性的实验研究     

姚慎辉  侯吉强 《成都信息工程学院学报》1995,(3)

对ＣＡＴＶ系统中的同轴传输线出现的特定问题作了理论分析和实验研究。对ＣＡＴＶ系统的工程设计、安装和调试具有实际意义。  相似文献   

蓝牙在嵌入式车载导航定位系统中的应用     

许正  范跃祖 《全球定位系统》2005,30(5):18-22

通过分析车载导航定位系统主流实现技术GPS＋DR组合定位技术所存在的问题，提出了路标传感器定位技术，它借助蓝牙短距离无线通讯技术实现车载系统及路标的通讯连接及数据传输；提出了系统整体实现方案，证明该定位系统具有实际的应用价值，可满足用户的需求，有一定的发展空间。  相似文献   

广东气象短信系统体系结构简介     

李娜  郑延庆 《广西气象》2005,26(2):47-48

介绍广东气象短信三期系统平台的构建背景、体系结构和发送流程，为各省市气象短信平台建设提供参考。  相似文献   

Multi-scale pore structure of COx claystone: Towards the prediction of fluid transport     

《Marine and Petroleum Geology》2015

We aim to relate the morphology of the pore network of finely porous claystones to their fluid transport properties. By using Focused Ion Beam in combination with Scanning Electron Microscopy (FIB/SEM), we image the pore network of COx claystone from 2D image stacks and as 3D reconstructed volumes. Our FIB/SEM samples are representative of the mesoscopic matrix clay. Porosity resolvable by this technique is in the range 1.7–5.9% with peak pore sizes of 50–90 nm. 3D pore network skeletonization provides connected pore volumes between end surfaces, tortuosity, density, and shortest pore paths with their pore size distribution. At higher resolution, 2D transmission electron microscopy (TEM) reveals large amounts of smaller pores (2–20 nm) between clay aggregates, associated to a local porosity of 14–25%, and peak sizes of 4–6 nm. Liquid permeability predictions with Katz–Thompson model, at the FIB/SEM volume scale and at the TEM surface scale, are in good agreement with macroscopic measurements (on the order of 10⁻²⁰ m²), showing that both mesopore sizes (peaks at 50–90 nm and 4–6 nm), located within the clay matrix, contribute to liquid transport.  相似文献   

论稳定电流场的入射、反射、透射间的关系          下载免费PDF全文

傅平 《地球物理学报》1994,37(1):108-114

根据分界面上稳定电流场的边界条件，解稳定电流场Ｌａｐｌａｃｅ方程，给出椭球形分界面入射场、反射场及透射场的表达式，并导出圆柱形、球形分界面上入射角、反射角及透射角的关系式后，指出，只在少数特殊情况下三者才相等，对一般形状的大多数光滑连续分界面情况，它们是不相等的．其值取决于分界面的具体形状．  相似文献   

A study by electron microscopy of gold and associated minerals from Round Mountain,Nevada     

《Ore Geology Reviews》2017

Details regarding the mineralization patterns of gold in epithermal systems are poorly understood. A refined understanding of gold microtextures, the interface between gold and associated minerals, and the role that nanoparticles play in gold mineralization could provide insight into the details of gold growth and may contain indicators of gold ore concentration mechanisms. Furthermore, a refined understanding of the interface also may explain variation in cyanide leaching extraction efficiency and may enable enhancement of recovery methods. Macrocrystalline gold samples from Round Mountain, Nevada were analyzed using field emission scanning electron microscopy and transmission electron microscopy. This study suggests that gold nanoparticles are common in Round Mountain gold and associated mineral phases, and may play an important role in the formation of macrocrystalline gold in this deposit. Microtopographic evidence indicates that the two dimensional nucleation and growth mechanism is dominant and nanotextural evidence suggests that nanoparticulate gold was the first stage of growth in the formation of these macrocrystalline samples that grew rapidly at high degrees of supersaturation. Results suggest that the interface between gold and quartz and other related minerals is far more complex than previously thought, and that textures present at the interface and in the bulk gold can help explain mineralization history and can also have implications for gold recovery efficiency for macrocrystalline bearing ore.  相似文献   

Improving Airgun Signal Detection with Small-Aperture Seismic Array in Yunnan   总被引：1，自引：1，他引：0  

WANG Weijun  ZHOU Qingyun  KOU Huadong  LIU Guiping  ZHU Hongbo  YAN Kun 《中国地震研究》2019,33(2):248-264

Repeating airgun sources are eco-friendly sources for monitoring the changes in the physical properties of subsurface mediums, but their signals decay quickly and are buried in the noises soon after traveling short distances. Stacking waveforms from different airgun shots recorded by a single seismic station (shot stacking) is the most popular technique to detect weak signals from noisy backgrounds, and has been widely used to process the data of Fixed Airgun Signal Transmission Stations (FASTS) in China. However, shot stacking sacrifices the time resolution in monitoring to recover a qualified airgun signal by stacking many shots at distance stations, and also suffers from persistent local noises. In this paper, we carried out several small-aperture seismic array experiments around the Binchuan FAST Station (BCFASTS) in Yunnan Province,China, and applied the array technique to improve airgun signal detection. The results show that seismic array processing combining with shot stacking can suppress seismic noises more efficiently, and provide better signal-to-noise ratio (SNR) and coherent airgun signals with less airgun shots. This work suggests that the array technique is a feasible and promising tool in FAST to increase the time resolution and reduce noise interference on routine monitoring.  相似文献   

震后废墟中Wi-Fi信号场强传输模型研究     

何志学  钟晓玲  宋庆艳  陈会丽  李龙 《震灾防御技术》2017,12(4):997-1004

针对震后废墟中无法精确检测出电磁波的传输特性问题,本文提出了一种在震后废墟中Wi-Fi信号场强的检测方法。首先是对Wi-Fi信号场强在组成震后废墟主要介质中的传输特性进行检测推导。然后通过测量在废墟不同距离下场强的大小,即可推导出废墟下电磁波的场强与传输距离的关系,最后得出场强在震后废墟中的传输模型。实验表明,该传输模型的计算结果准确度高,对震后废墟中电磁波传输特性的检测具有重要意义。  相似文献