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Search Results: 1 - 10 of 262101 matches for " 张磊 "
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强震前近震中区地电场异常研究
Geoelectric Field Ratio Anomalies near Epicenter Area before Earthquakes
 [PDF]

, 田山
Electromagnetic Analysis and Applications (EAA) , 2013, DOI: 10.12677/EAA.2013.21002
Abstract:

对国内地电场观测的分析结果表明,地电场观测资料中存在着各种不规则的扰动变化和多种频谱的周期性变化,这种与地磁场或者固体潮正常变化相关的电场变化和地震前兆变化混杂在一起,很难从原始资料中识别和提取地震前兆信息。考虑到与地震有关的近场变化对地震预测的研究更具实际意义,本文中选取了汶川、玉树地震震源区附近的39个台站和文安地区12个台站的地电场观测资料,通过计算同台、同测向观测资料的长、短极距测值的比值对地震前兆信息进行分析、研究。结果表明,震中区的多数台站地电场的比值震前存在不同形态的异常变化。
The analysis of geoelectric observation in Chinaindicates that geoelectric data contain various irregular changes and multiform spectrum periodic changes. These changes are correlated with normal geomagnetic field or earth tide and mixed with seismic precursor information, which make it difficult to detect and extract seismic precursor information from raw data. Considering that changes in near field are more significant to earthquake prediction, the data from 39 stations near the epicenter area of Wenchuan and Yushu earthquake and 12 near the epicenter area of Wen’an earthquake have been collected in order to calculate the ratio for further research using the long and short dipole distance observation data in the same direction of the same station. The result indicates that most of the stations appear ratio anomaly with different shape before an earthquake in the epicenter area.

无线传感器网络测试技术研究
Research of Sniffer Technology of Wireless Sensor Network
 [PDF]

, 袁明辉
Hans Journal of Wireless Communications (HJWC) , 2011, DOI: 10.12677/hjwc.2011.12009
Abstract: 为了有效地分析和评估无线传感器网络(WSN:Wireless Sensor Network)性能,提出一种基于TinyOS的Sniffer网络设计,通过监测IEEE802.15.4协议帧来监测整个网络
In order to effectively analysis and evaluate the performance of Wireless Sensor Network (WSN: Wireless Sensor Network), a design of sniffer network based on TinyOS was proposed to monitor the whole network through monitoring the IEEE802.15.4 frame.
渭河流域水文变异识别与初步解析
Hydrological Variation Analysis in Wei River Basin
 [PDF]

洪波,
Journal of Water Resources Research (JWRR) , 2014, DOI: 10.12677/JWRR.2014.31001
Abstract: 应用滑动秩和检验法与Mann-Kendall方法对渭河干支流主要的7个水文站点的水文序列变异点的位置进行诊断与识别。结合Hilbert-Huang变换,对各水文站点数据进行EMD多尺度分解,获得不同时间尺度的IMF信号和趋势过程,然后采用滑动秩和检验法对各分解信号进行变异识别,确定变异的响应尺度。最后,结合水文变异指标(IHA),以变异点位置为依据,进行阶段划分,识别变异前后水文序列的变异领域,对水文情势变异进行细节解析,找出发生强烈变异的水文指标。结果表明:1) 渭河干流水文站点年径流序列的变异点主要发生在1971年和1994年,1971年的水文变异主要由人类活动驱动,而1994年的水文变异则由气候变化与人类活动共同影响。2) 水文变异主要影响渭河干支流径流序列的趋势过程,只有华县站6年时间尺度变化及状头站4~6年时间尺度变化过程受到水文变异的扰动。3)
慢性非萎缩性胃炎诊断方法与标准的研究进展
Research Progress of Chronic Non-Atrophic Gastritis Diagnostic Methods and Diagnostic Criteria
 [PDF]

, 郭岩
Advances in Clinical Medicine (ACM) , 2014, DOI: 10.12677/ACM.2014.41002
Abstract:
慢性非萎缩性胃炎(CSG)是最为常见的消化系统疾病之一,其发病率约占慢性胃炎的59.3%,但因其症状与体征缺乏特异性、内镜下表现的不典型性,所以在临床上漏诊率与误诊率均较高,目前国内外医学界对慢性非萎缩性胃炎尚无明确的诊断标准,本文深入探讨了病理检查、胃镜检查、胃黏膜的血色素含量血色素指数测定、幽门螺杆菌检测、超敏C-反应蛋白检验对诊断CSG的意义,并对CSG诊断方法与诊断标准提出建议
Chronic non-atrophic gastritis (CSG) is one of the most common diseases in the digestive system, the incidence of which is about 59.3%. Since the lack of specific symptoms or signs, and no typical features on endoscopy, the rate of missed diagnosis and misdiagnosis of CSG is very high. Currently, there are no clear clinical diagnostic criteria applied to CSG. This article discusses the factors including pathologic examination, endoscopy, index of hemoglobin, Helicobacter pylori, HS-CRP, which have the diagnosis significance to CSG, and gives suggestions to CSG diagnostic methods and diagnostic criteria
基于分布式光纤测温的电缆故障监测系统设计与实现
Design and Implementation of Cable Fault Monitoring System Based on Distributed Optical Fiber Temperature Sensor
 [PDF]

, 刘代
Smart Grid (SG) , 2016, DOI: 10.12677/SG.2016.64020
Abstract:
电缆沿线的温度实时监测是保障其安全运行的重要手段。在理论分析光纤后向拉曼散射和光时域反射原理的基础上,设计了分布式光纤测温系统和方案和软件构架,并将设计的系统应用于动力电缆的在线监测,取得了良好的测试结果,为动力电缆的故障预警提供了可靠的科学手段。
Real-time monitoring of temperature along the cable is very important for ensuring the safe oper-ation. Based on the theoretical analysis of Raman back scattering of optical fiber and optical time domain reflection principle, optical fiber distributed temperature measurement system, scheme and software architecture are designed. The system is applied to the online monitoring of power cable, and good results are achieved. It provides a reliable scientific tool for the fault early warning of power cable.
DOI:10.7524/j.issn.0254-6108.2014.08.001
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环境化学 , 2015,
Abstract: 为了解青岛市售不同种贝类的汞污染情况及居民通过食用贝类引起的汞健康风险,于2012年10月至2013年4月,在青岛8个行政区采集菲律宾蛤仔、鲍鱼、海螺、香螺、牡蛎、缢蛏、文蛤、扇贝,共8种贝类,181份样品.采用F732-V型冷原子吸收测汞仪对贝类中的总汞含量进行测定.所测8种贝类的汞含量范围为0.001—0.098mg·kg-1,菲律宾蛤仔、扇贝、文蛤、缢蛏、鲍鱼、海螺、牡蛎和香螺的平均汞含量分别为0.020、0.039、0.012、0.013、0.031、0.030、0.021、0.020mg·kg-1.在青岛市售贝类的各产地中,红岛所产贝类的汞含量最高,为0.046mg·kg-1,其次是龙口,为0.027mg·kg-1,产于乳山和日照的贝类汞含量最低,分别为0.002mg·kg-1和0.003mg·kg-1.所采集全部贝类样品中的总汞含量均低于我国国家标准.汞摄入量计算结果显示,青岛居民食用贝类导致的汞摄入量远远低于FAO/WHO推荐Hg的日摄入量.采用美国环保署新制定参考剂量计算的目标危险系数(THQ)结果显示,青岛市儿童通过食用贝类产品有非常高的汞暴露健康风险.
基于KingHistorian数据采集远程监控系统研究与实现
Data Acquisition and Remote Monitoring System Based on KingHistorian
 [PDF]

, 胡攀
Sustainable Energy (SE) , 2011, DOI: 10.12677/se.2011.11004
Abstract: 开发了基于KingHistorian的数据采集和处理系统,实时监控分布在不同地点的数据信息。该监控系统为分布在异地的采集点提供统一的数据采集方式,统一的工业实时数据库,为各业务应用模块提供统一的数据接口服务,并实现了C/S、B/S两种模式的访问。
This paper described a data acquisition and processing system based on KingHistorian, it can monitor data in different locations in real time. And it provide unified data acquisition method and industrial real-time database for remote distribution data collection points, also provide a unified interface service for all kinds of application modules and realize C/S, B/S mode access.
THE NUMERICAL METHOD OF DISCRIMINATINC STABILITY FOR SECOND ORDER LINEAR SYSTEM
二阶线性系统稳定性判定的数值方法


计算数学 , 1981,
Abstract: For discriminating stability of a linear system, there were two kinds of thenumerical methods. One is based all computed coefficients of characteristic polynomial,the other ia based on all eigenvalues which are computed. This paper suggests amethods, it is numerical stable than the former and less work than the latter. Moreover,there are some different features from both.
THE SOLVABILITY CONDITIONS FOR THE INVERSE PROBLEM OF SYMMETRIC NONNEGATIVE DEFINITE MATRICES
对称非负定矩阵反问题解存在的条件


计算数学 , 1989,
Abstract: R~(n×m)表示所有n×m阶实阵集合,R_r~(n×m)表示R~(n×m)中秩为r的子集.R_K表示所有K阶对称非负定阵集合.A≥0(>0)表示方阵A对称非负定(正定).R(A),N(A),A~+分别表示A的列空间,零空间和Moore-Penrose广义逆.dim(·)表示子空间维数,I_K表示K阶单位阵.||·||表示Frobenius范数.现考虑如下问题:
A KIND OF INVERSE PROBLEMS OF MATRICES AND ITS NUMERICAL SOLUTION
一类矩阵反问题及其数值解法


计算数学 , 1987,
Abstract: 1.问题的提法 R~(n×m)表示所有n×m阶实矩阵的集合,R~(n×1)=R~n,R_r~(n×m)表示R~(n×m)中秩为r的子集.||·||取Frobenius范数.若?0≠x∈R~n,α≥0,有x~TAx≥αx~Tx(>αx~Tx),则记为A≥α(>α).若A≥0(>0)且A=A~T,则A为对称半正定(正定)阵. 令
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