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Complex permittivity, permeability, and microwave absorption of barium ferrite by citrate sol-gel process

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Rare Metals 2003年第2期22卷 125-130页

作者： ZHANGHaijun WUMingzhong YAOXi ZHANGLiangying HighTemperatureceramicsinstitute ZhengzhouUniversityZhengzhou450052China ~FunctionalMaterialsResearchtLaboratory TongjiUniversityShanghai200092China

BaFe12O19 hexaferrites were prepared by citrate sol-gel process. The formation temperature was much lower than that of the conventional ceramic method. The complex dielectric constant and complex permeability of hexaferrite-paraffin wax composites had been measured by the transmission/reflection coaxial line method in the range from 200 MHz to 6 GHz. The measurement results showed that both the complex dielectric constant and dielectric loss exhibited no significant variation with the measuring frequency increase. It also showed that the real part of permeability decreased as the frequency increasing for all samples, the resonance phenomena due to domain wall resonance was observed in ?' spectra, the calcining temperature strongly affects the microwave properties of BaFe12O19 ferrites, the higher the calcining temperature, the lower the resonance frequency.

关键词： BaFe12O19 inorganic nonmetal materials hexaferrites sol-gel BaFe12O19, microwave properties

High-accuracy topographical information extraction based on fusion of ASTER stereo-data and ICESat/GLAS data in Antarctica

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Science china Earth Sciences 2009年第5期52卷 714-722页

作者： E DongChen1,3,SHEN Qiang2,XU Ying1,3 & CHEN Gang4 1 Chinese Antarctic Center of surveying and mapping,Wuhan University,Wuhan 430079,china 2 institute of Seismology china Earthquake Administration,Wuhan 430071,china 3 Key Laboratory of Polar surveying and mapping,State Bureau of surveying and mapping,Wuhan University,Wuhan 430079,china 4 Department of Geography,University of Calgary,Calgary,Alberta T2N 1N4,Canada Chinese Antarctic Center of surveying and mapping Wuhan University Wuhan China Key Laboratory of Polar surveying and mapping State Bureau of Surveying and Mapping Wuhan University Wuhan China institute of Seismology china Earthquake Administration Wuhan China Department of Geography University of Calgary Calgary Canada

In order to better support Antarctic inland ice sheet expedition from Zhongshan Station to Dome A,the topographic data are *** present,although the entire Antarctic DEM provided by RAMP(Ra-darsat Antarctic mapping Project) was estimated at the highest horizontal(spatial) resolution of about 200 m,the real horizontal resolution of the DEM varies from place to place depending on the density and scale of the original source *** ice shelves and the inland ice sheet,the horizontal resolution is about 5 km;the vertical accuracy is estimated to be ±50 m in interior East Antarctic ice sheet and away from the mountain ***,more accurate topographic data are unavailable in *** order to meet the requirements of high-accuracy topographic information for further researches,this paper mainly addresses a fusion study of ASTER stereo pairs and ICESat/GLAS altimetry data for extraction of high-accuracy DEM in East Antarctica,based on the high horizontal resolution(15 m) of ASTER and vertical accuracy(13.8 cm) of ICESat/***,some altimetry data were selected as vertical control points to reduce errors of image correlation matching during the extraction of ASTER-based ***,ice sheet altimetry data derived from ICESat were used to generate DEM ranging from 75° to 81°S because existing ASTER data do not cover this area and high density of the coverage of ICESat altimetry ***,the DEM in coverage of the expedition route was *** analysis of result reveals that the DEM accuracy is improved *** absolute vertical accuracy of DEM is higher than 15 m in some cases and higher than 30 m for all the areas along the expedition route except from the 009-001 scene;the interior accuracy is higher than 15 m and higher than 7 m in some *** can meet the requirements of topographic map at 1:50000 scale,which is an economic and advantageous method to produce the topographic products.

关键词： DEM Antarctica Zhongshan Station Dome A ASTER ICESat GLAS

基于BLOB区域和边缘特征分析的准直图像双光学目标识别方法

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光子学报 2024年第2期53卷 244-266页

作者：何文轩王拯洲魏际同王力弋东驰中国科学院西安光学精密机械研究所西安710119 中国科学院大学北京100039

针对光路对接准直目标识别算法对双目标粘连状态无法判别的问题,提出了基于二进制大对象(Binary Large Object,BLOB)区域和边缘特征分析的准直图像双光学目标识别方法。首先,对二值化图像进行数字形态学处理,计算全图各BLOB区域的面积... 详细信息

针对光路对接准直目标识别算法对双目标粘连状态无法判别的问题,提出了基于二进制大对象(Binary Large Object,BLOB)区域和边缘特征分析的准直图像双光学目标识别方法。首先,对二值化图像进行数字形态学处理,计算全图各BLOB区域的面积、中心、轴长、区域、有效BLOB区域个数等信息。其次,对有效BLOB区域个数大于1的完全分离双目标准直图像,统计各BLOB区域中心分别为位于两个面积最大的BLOB区域内的BLOB数量,数量小的候选BLOB区域为主激光目标,数量大的候选BLOB区域为模拟光目标。然后,对于有效BLOB区域个数等于1的待识别图像,从左、右、上、下4个方向分别提取模板边缘图像的有效坐标序列和待识别边缘图像坐标序列,搜索有效坐标序列和待识别边缘图像坐标序列的最大相关系数对应的有效坐标序列。当4个方向的相关系数全部大于0.95时,待识别图像为模拟光目标;当4个方向的相关系数都小于0.95时,待识别图像为主激光目标;否则待识别图像为粘连图像。实验结果表明:提出的双光学目标识别算法,不仅能够识别完全分离的模拟光目标和主激光目标,误差小于3个像素,处理时间小于1 s,而且能够判别处于粘连状态的光学目标和单个独立的光学目标,满足光路对接准直图像识别算法对于自适应性、精度和效率的要求。

关键词：光路对接准直 BLOB区域边缘特征分析双光学目标识别粘连图像识别

Enhancement of H_2 Sensing Properties of In_2O_3-based Gas Sensor by Chemical Modification with SiO_2

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Chinese Chemical Letters 2004年第12期15卷 1509-1512页

作者： Zi Li ZHAN Deng Gao JIANG Jia Qiang XU School of Chemical Engineering, zhengzhou University, zhengzhou 450002 Department of Chemical Engineering, zhengzhou institute of Light Industry,zhengzhou 450002 School of Chemical Engineering Zhengzhou University Zhengzhou 450002 China Department of Chemical Engineering Zhengzhou Inst. of Light Industry Zhengzhou 450002 China

The sensitivity and selectivity to H_2 of a new In_2O_3-based gas sensor were improvedsignificantly by surface chemical modification. A dense layer of SiO_2 near the surface of the porousIn_2O_3 bead was formed by chemical vapor deposition(CVD)of diethoxydimethysilane(DEMS).The dense layer functioned as a molecular sieve, thereby the diffusion of gases with large moleculardiameters,except for H_2, was effectively controlled, resulting in a prominent selectivity and highsensitivity for H_2. The working mechanism of the sensor was also presented.

关键词： H_2 gas sensor indium oxide molecular sieve.

Proton induced X-ray emission (PIXE) analysis of sources of porcelain body of Ru Guan and Jun Guan porcelains

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Science china(Physics,Mechanics & Astronomy) 2006年第4期49卷 411-420页

作者： LI Guoxia1, ZHAO Weijuan1, LI Rongwu2, SUN Hongwei1, GUO Min1, WANG Yanfang1, LIU Hui1, ZHAO Qingyun3, SUN Xinmin3, ZHAO Wenjun3 & CHENG Huansheng4 1. Faculty of Physical Engineering, zhengzhou University, zhengzhou 450052, china 2. Department of Physics, Beijing Normal University, Beijing 100875, china 3. institute of Cultural Relic and Archaeology of Henan Province, zhengzhou 450000, china 4. institute of Modern Physics, Fudan University, Shanghai 200433, china Faculty of Physical Engineering Zhengzhou University Zhengzhou China Department of Physics Beijing Normal University Beijing China institute of Cultural Relic and Archaeology of Henan Province Zhengzhou China institute of Modern Physics Fudan University Shanghai China

34 samples of Ru Guan porcelain body and 50 samples of Jun Guan porcelain body (both kinds being in different body colors) were selected with the purpose of finding out the source of raw materials and their classification relationship so as to search for ways of non-destructive discrimination. Proton induced X-ray emission (PIXE) has been applied to these samples to determine their chemical elements. The data of seven major chemical elements collected from these samples were further studied through fuzzy cluster analysis. Results indicate that the origin of raw materials of Jun Guan porcelain body samples is comparatively more concentrated in certain places, while that of Ru Guan porcelain body samples is scattered about. The places of origin of raw materials of the majority of Ru Guan and Jun Guan porcelain body samples have something in common, but some differences still exist. It might be an important way for non-destructive discrimination among Ru Guan and Jun Guan porcelains by combining PIXE with fuzzy cluster analysis.

关键词： Ru Guan and Jun Guan porcelain, source of porcelain body, PIXE, fuzzy cluster analysis, non-destructive discrimination.

The Writing Style of Hemingway

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中州大学学报 2003年第3期20卷 51-52页

作者： XU Jing(zhengzhou Economic Management institute,zhengzhou 450052,china) zhengzhouEconomicManagementinstitute Zhengzhou450052China

Ernest Hemingway is a remarkable man as well as a remarkable writer . His own ex perience has an enormous impact on his novels . His writing style is special . T he characters in Hemingway’s novels are just like him ... 详细信息

关键词：海明威写作风格个人经历人物形象小说评价

THE EQUIVALENCE CLASSES OF LRS OVER Z_p^e

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Systems Science and Mathematical Sciences 1998年第2期11卷 175-180页

作者： ZHU Yuefei(Department of APPlied Mathematics, zhengzhou InformationEngineering institute, zhengzhou 450002, china) 解放军信息工程学院应用数学系河南郑州 450002

In this paper, we discuss the counting of translation equivalellce classes oflinear recurrence sequences over Zap. For more general linear recurrence relation, we countthe number of translation equivalent classes of l... 详细信息

关键词： Sequence translation equivalence module ideal.

Comparison of Two Algorithms on Improving GPS/INS Positioning Accuracy During GPS Outage

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Comparison of Two Algorithms on Improving GPS/INS Positionin...

The Simultaneous Approximation Order by Hermite Interpolation in a Smooth Domain

第三届中国卫星导航学术年会

作者： Wanliang Hao, Fuping Sun, Po Chen institute of surveying and mapping, University of Information Engineering, zhengzhou 450052, china

Aiming at the problem that the navigation errors increased rapidly when the GPS signal is unavailable in the GPS/INS integrated navigation system. Firstly, the characteristics of Fixed-Interval Smoothing algorithm in post-processing is researched, and RTS（Rauch-Tung-Striebel） smoothing is adopted to process the data during GPS outage. Secondly, a PEM（Parametric Error Model） that can be used in near real-time or post-processing is developed, and the scope of applications of the model is discussed. At last, both methods are compared using the simulation data, the results show that either of them can improve the navigation accuracy during GPS outage, and the advantages and disadvantages of the two algorithms are analyzed.

关键词： GPS/INS Outage Smoothing RTS PEM

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Acta Mathematica Sinica,English Series 2002年第4期18卷 631-646页

作者： Tian Liang TU Department of Information Engineering, North china institute of Hydroelectricity, zhengzhou 450045, P. R. china Department of Information Engineering North China Institute of Hydroelectricity Zhengzhou P. R. China

Let D be a smooth domain in the complex plane. In D consider the simultaneous ap- proximation to a function and its ith (0≤i≤q) derivatives by Hermite interpolation. The orders of uniform approximation and approximation in the mean, are obtained under some domain boundary conditions. Some known results are included as particular cases of the theorems of this paper.

关键词： Simultaneous appoximation Hermite interpolation Approximation order Smooth domian