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ON THE CELL ENTROPY INEQUALITY FOR THE FULLY DISCRETE RELAXING SCHEMES

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Journal of Computational Mathematics 2001年第5期19卷 511-518页

作者： hua-zhong Tang hua-mo Wu School of Mathematical Sciences Peking UniversityBeijing 100871China LSEC JCMSECAcademy of Mathematics and Systems SciencesChinese Academy of SciencesBeijing 100080China

Presents a study on the cell entropy inequality for two classes of fully discrete relaxing schemes approximating scalar conservation laws. Main advantage of the schemes; Review of the construction of the relaxing syst... 详细信息

关键词： the relaxing schemes entropy inequality conservation laws

物理气相沉积热障涂层批量生产用球坑仪快速测厚法研究

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真空 2022年第6期59卷 73-77页

作者：邓仲华常振东徐雷胡江玮蔡妍牟仁德京东方科技集团股份有限公司北京100016 中国航发北京航空材料研究院北京100095

为了满足热障涂层批量生产时对厚度快速、准确检测的需要,本文选用球坑测厚法对物理气相沉积热障涂层厚度进行了测量研究。首先在GH3039高温合金基体上分别制备厚约120μm的NiCrAlYSi涂层和Zr O_(2)·Y_(2)O_(3)(YSZ)涂层,研究了研磨液... 详细信息

为了满足热障涂层批量生产时对厚度快速、准确检测的需要,本文选用球坑测厚法对物理气相沉积热障涂层厚度进行了测量研究。首先在GH3039高温合金基体上分别制备厚约120μm的NiCrAlYSi涂层和Zr O_(2)·Y_(2)O_(3)(YSZ)涂层,研究了研磨液粒径、研磨时间等参数与磨坑直径的关系,随后根据试验结果对高温合金试片涂覆的NiCrAlYSi/YSZ热障涂层使用球坑测厚法进行了厚度测量,并与金相测厚法结果进行了对比。结果表明:NiCrAlYSi涂层和YSZ涂层磨坑直径与研磨时间均满足抛物线增加关系;相同条件下,所用研磨液粒径为5μm和10μm时获得的磨坑直径相当,均比1μm时的大;针对同一涂层,球坑测厚法与金相测厚法测量结果吻合度高,误差在6%以内。

关键词：热障涂层物理气相沉积涂层厚度球坑仪

On Duality in Filtered Cohomologies

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Acta Mathematica Sinica,English Series 2019年第5期35卷 597-608页

作者： hua zhong KE School of Mathematics Sun Yat-sen University

For a symplectic manifold(M^(2n), ω) without boundary(not necessarily compact), we prove Poincaré type duality in filtered cohomology rings of differential forms on M, and we use this result to obtain duality betwee... 详细信息

关键词： Symplectic manifolds filtered cohomology Lefschetz map

A new modified remote user authentication scheme using smart cards

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Applied Mathematics(A Journal of Chinese Universities) 2008年第3期23卷 371-376页

作者： SHEN zhong-hua School of Sci. Hangzhou Normal Univ. Hangzhou 310036 China

In 2000, a remote user authentication scheme using smart cards was proposed and the masquerade attacks were proved successful on this scheme. Recently, Kumar has suggested the idea of check digits to overcome the above attacks with a new scheme that removes these threats well. In this paper it is pointed out that the weakness still exists in Kumar＇s scheme, and the intruder can login to the remote system through having some information. A new scheme which can overcome these attacks and appears more secure and efficient than Kumar＇s is presented.

关键词： remote user authentication smart card cryptography

轮状病毒Rotateq及Rotarix疫苗VP8~*蛋白的原核表达、纯化与鉴定

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湖南师范大学学报（医学版） 2019年第3期16卷 4-7页

作者：邓中华郭妮君陈杰谭超超熊艺灿曹友德湖南师范大学第一附属医院湖南省人民医院长沙410005 湖南省妇幼保健院长沙410000

目的 :通过大肠埃希菌原核表达体系,分别获得轮状病毒疫苗Rotateq及Rotarix的VP8*基因表达产物,为深入研究轮状病毒VP8*蛋白的结构和功能奠定基础。方法 :基因合成轮状病毒疫苗Rotateq及Rotarix的P[8]型VP8*基因序列,将其克隆到携带有GS... 详细信息

目的 :通过大肠埃希菌原核表达体系,分别获得轮状病毒疫苗Rotateq及Rotarix的VP8*基因表达产物,为深入研究轮状病毒VP8*蛋白的结构和功能奠定基础。方法 :基因合成轮状病毒疫苗Rotateq及Rotarix的P[8]型VP8*基因序列,将其克隆到携带有GST标签的pGEX-4T1表达载体中构建重组质粒pGEX-4T1-VP8*,测序正确后转化大肠杆菌BL21(DE3),通过SDS-PAGE电泳检测表达产物,并通过Glutathione Sepharose 4B纯化柱进行纯化,Western Blot鉴定。结果 :SDS-PAGE电泳结果显示分子量52KD处有深染带,Western-Blot显示该处蛋白能与GST标签抗体结合。结论 :成功构建了包含Rotateq及Rotarix VP8*基因的重组表达载体pGEX-4T1-VP8*,获得了可溶性GST-VP8*重组蛋白。

关键词：轮状病毒 Rotateq疫苗 Rotarix疫苗原核表达 VP8*蛋白

Abdominal aortic aneurysm： Treatment options, image visualizations and follow-up procedures

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Journal of Geriatric Cardiology 2012年第1期9卷 49-60页

作者： zhong-hua Sun Discipline of Medical Imaging Department of lmaging and Applied Physics Curtin University Perth Western Australia 6845 Australia

Abdominal aortic aneurysm is a common vascular disease that affects elderly *** surgical repair is regarded as the gold standard technique for treatment of abdominal aortic aneurysm,however,endovaseular aneurysm repair has rapidly expanded since its first introduction in *** a less invasive technique,endovascular aneurysm repair has been confirmed to be an effective alternative to open surgical repair,especially in patients with co-morbid *** tomography （CT） angiography is currently the preferred imaging modality for both preoperative planning and post-operative follow-up.2D CT images are complemented by a number of 3D reconstructions which enhance the diagnostic applications of CT angiography in both planning and follow-up of endovascular *** has the disadvantage of high cummulative radiation dose,of particular concern in younger patients,since patients require regular imaging follow-ups after endovascular repair,thus,exposing patients to repeated radiation exposure for *** is a trend to change from CT to ultrasound surveillance of endovascular aneurysm *** image visualizations demonstrate excellent morphological assessment of aneurysm and stent-grafts,but fail to provide hemodynamic changes caused by the complex stent-graft device that is implanted into the *** article reviews the treatment options of abdominal aortic aneurysm,various image visualization tools,and follow-up procedures with use of different modalities including both imaging and computational fluid dynamics *** directions to improve treatment outcomes in the follow-up of endovascular aneurysm repair are outlined.

关键词： Abdominal aortic aneurysm Computed tomography Follow-up Stent graft Treatment Visualization.

Research into a Feature Selection Method for Hyperspectral Imagery Using PSO and SVM

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Journal of China University of Mining and Technology 2007年第4期17卷 473-478页

作者： YANG hua-chao ZHANG Shu-bi deng Ka-zhong DU Pei-jun School of Environment ＆ Spatial Informatics China University of Mining ＆ Technology Xuzhou Jiangsu 221008 China

Classification and recognition of hyperspectral remote sensing images is not the same as that of conventional multi-spectral remote sensing images. We propose,a novel feature selection and classification method for hyperspectral images by combining the global optimization ability of particle swarm optimization (PSO) algorithm and the superior classification performance of a support vector machine (SVM). Global optimal search performance of PSO is improved by using a chaotic optimization search technique. Granularity based grid search strategy is used to optimize the SVM model parameters. Parameter optimization and classification of the SVM are addressed using the training date corre-sponding to the feature subset. A false classification rate is adopted as a fitness function. Tests of feature selection and classification are carried out on a hyperspectral data set. Classification performances are also compared among different feature extraction methods commonly used today. Results indicate that this hybrid method has a higher classification accuracy and can effectively extract optimal bands. A feasible approach is provided for feature selection and classifica-tion of hyperspectral image data.

关键词： hyperspectral remote sensing particle swarm optimization support vector machine feature extraction

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光学界面检测仪在兰郑长成品油管道上的应用

管道技术与设备 2016年第1期 22-24页

作者：沈亮刘佳李章清邓中华王大鹏高宏扬丁俊刚中国石油北京油气调控中心北京100007 中油管道检测技术有限责任公司河北廊坊065000 中国石油西南管道公司兰州分公司甘肃兰州730060

FUEL CHECK光学界面检测仪非常适用于检测光折射率有一定差别的界面,已成功应用于兰郑长管道批次界面检测并发挥了重要作用。文中对FUEL CHECK光学界面检测仪的原理、系统组成、标定方式等进行了介绍,并结合兰郑长管道实际应用情况对检... 详细信息

FUEL CHECK光学界面检测仪非常适用于检测光折射率有一定差别的界面,已成功应用于兰郑长管道批次界面检测并发挥了重要作用。文中对FUEL CHECK光学界面检测仪的原理、系统组成、标定方式等进行了介绍,并结合兰郑长管道实际应用情况对检测仪的具体配置和检测效果进行了分析,对光学界面检测仪的使用及维护提出了建议。

关键词：成品油管道光学界面检测仪密度计

HIGH RESOLUTION SCHEMES FOR CONSERVATION LAWS AND CONVECTION-DIFFUSION EQUATIONS WITH VARYING TIME AND SPACE GRIDS

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Journal of Computational Mathematics 2006年第2期24卷 121-140页

作者： hua-zhong Tang Gerald Warnecke LMAM School of Mathematical Sciences Peking University Beijing 100871 China Institut fiir Analysis und Numerik Otto-von-Guericke Universitat Magdeburg 39106 Magdeburg Germany

This paper presents a class of high resolution local time step schemes for nonlinear hyperbolic conservation laws and the closely related convection-diffusion equations, by projecting the solution increments of the underlying partial differential equations （PDE） at each local time step. The main advantages are that they are of good consistency, and it is convenient to implement them. The schemes are L^∞ stable, satisfy a cell entropy inequality, and may be extended to the initial boundary value problem of general unsteady PDEs with higher-order spatial derivatives. The high resolution schemes are given by combining the reconstruction technique with a second order TVD Runge-Kutta scheme or a Lax-Wendroff type method, respectively. The schemes are used to solve a linear convection-diffusion equation, the nonlinear inviscid Burgers＇ equation, the one- and two-dimensional compressible Euler equations, and the two-dimensional incompressible Navier-Stokes equations. The numerical results show that the schemes are of higher-order accuracy, and efficient in saving computational cost, especially, for the case of combining the present schemes with the adaptive mesh method [15]. The correct locations of the slow moving or stronger discontinuities are also obtained, although the schemes are slightly nonconservative.

关键词： Hyperbolic conservation laws Degenerate diffusion High resolution scheme,Finite volume method Local time discretization.