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The Association of BMI and WHR on Blood Pressure Levels and Prevalence of Hypertension in Middle-Aged and Elderly People in Rural China^1

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Biomedical and Environmental Sciences 2000年第3期13卷 189-197页

作者： ZHAOWEN－hua XUHENG－qing InstituteofNutritionandFoodHygiene ChineseAcademyofPreventiveMedicineBeijing100050China BureauofPublicHealthofAn－qingCity AnhuiProvinceChina

The purpose of this study was to examine the effects of BMI (Body Mass Index) and WHR (Waist Hip Ratio) on average blood pressure and the prevalence of hypertension in middle aged and elderly population in rural China. A total of 12955 subjects including 6276 males and 6688 females over 40 years of age were surveyed. Height, weight, waist circumference, hip circumference and blood pressure were measured. The association of BMI and WHR on average blood pressure levels and prevalence of hypertension were analyzed by dividing BMI and WHR into tertiles. The average blood pressure levels and the prevalence of hypertension in males and females increased significantly with the increase of BMI or WHR ( P <0.01), as well as with the increase of both of them ( P <0.01). The average blood pressure and the prevalence of hypertension stopped increasing when WHR was ≥0.76, suggesting that WHR ≥0.80 could be used as a cut off value for the prediction of hypertension risk for both males and females. Therefore hypertension could be effectively prevented and controlled by controlling BMI and WHR.

关键词： Rural China Elderly People blood pressure rural China

Choice of weights in FMA estimators under general parametric models

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Science China Mathematics 2013年第3期56卷 443-457页

作者： ZHANG XinYu zou Guohua LIANG hua Academy of Mathematics and Systems Science Chinese Academy of Sciences Center for Forecasting Science Chinese Academy of Sciences Department of Biostatistics and Computational Biology University of Rochester Medical Center

The choice of weights in frequentist model average estimators is an important but difficult problem. Liang et al. (2011) suggested a criterion for the choice of weight under a general parametric framework which is termed as the generalized OPT (GOPT) criterion in the present paper. However, no properties and applications of the criterion have been studied. This paper is devoted to the further investigation of the GOPT criterion. We show that how to use this criterion for comparison of some existing weights such as the smoothed AIC-based and BIC-based weights and for the choice between model averaging and model selection. Its connection to the Mallows and ordinary OPT criteria is built. The asymptotic optimality on the criterion in the case of non-random weights is also obtained. Finite sample performance of the GOPT criterion is assessed by simulations. Application to the analysis of two real data sets is presented as well.

关键词： asymptotic optimality likelihood inference model averaging model selection model selection diagnostics

Analysis and discussion on launching mechanism and tactical electromagnetic railgun technology

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Defence Technology（防务技术） 2018年第5期14卷 484-495页

作者： Bao-ming Li qing-hua Lin National Key Laboratory of Transient Physics Nanjing University of Science and TechnologyP.O.Box210094NanjingPR China China Academy of Ordnance P.O.Box100089BeijingPR China

This paper begins with a discussion on the significance of multi-physical fields in the research of railgun launching mechanism, followed by an introduction of research work about dynamic measurements and numerical simulations. The application of some measurement methods including the atomic emission spectrum, fiber-optic strain, optical level, pulsed X-ray, and high-speed video in observing the launching process was introduced. The models about the electromechanical dynamic processes and multi-physical fields in a railgun were developed. The mechanisms of the grooving, arc transition, and gouging were analyzed. These work provided a deeper understanding of launching mechanism of electromagnetic railgun. Some issues about the tactical railgun, such as the fiber composite overwrapped barrel, recoil,loading modes and eddy current loss were also discussed. Taking a medium-caliber launcher as an example, the basic process of design and analysis was introduced.

关键词： Railgun Launching mechanism Dynamic measurement Numerical simulation

L^p-L^q Estimates for a Class of Pseudo-Differential Equations and Their Applications

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Acta Mathematica Sinica,English Series 2011年第7期27卷 1435-1448页

作者： qing Quan DENG Xiao hua YAO Department of Mathematics Huazhong Normal University Wuhan 430079 P. R. China

This paper is concerned with the L^p-L^q estimates of the solutions for a class of pseudodifferential equations under some suitable degenerate assumptions. As applications, these estimates can be used to show that a generalized Schroedinger operator with some integrable potential generates a fractionally integrated group in L^p（R^n）.

关键词： Pseudo-differential equation,L^p-L^q estimate integrated group

An Interpolation of Hardy Inequality and Moser–Trudinger Inequality on Riemannian Manifolds with Negative Curvature

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Acta Mathematica Sinica,English Series 2016年第7期32卷 856-866页

作者： Yan qing DONG Qiao hua YANG School of Mathematics and Statistics Wuhan University

Let M be a complete, simply connected Riemannian manifold with negative curvature. We obtain an interpolation of Hardy inequality and Moser-Trudinger inequality on M. Furthermore, the constant we obtain is sharp.

关键词： Moser-Trudinger inequality Hardy inequality Riemannian manifold negative curvature

A Practical Group Key Management Algorithm for Cloud Data Sharing with Dynamic Group

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China Communications 2016年第6期13卷 205-216页

作者： Wei Song hua zou Haowen Liu Jun Chen State Key Laboratory of Software Engineering Wuhan University School of Computer Wuhan University International School of Software Wuhan University Lab of Storage and quantum computing University of Pittsburgh

Cloud data sharing service, which allows a group of people to work together to access and modify the shared data, is one of the most popular and efficient working styles in the enterprises. However, the cloud server is not completely trusted, and its security could be compromised by monetary reasons or caused by hacking and hardware errors. Therefore, despite of having advantages of scalability and flexibility, cloud storage service comes with privacy and the security concerns. A straightforward method to protect the user's privacy is to encrypt the data stored at the cloud. To enable the authenticated users to access the encrypted cloud data, a practical group key management algorithm for the cloud data sharing application is highly desired. The existing group key management mechanisms presume that the server is trusted. But, the cloud data service mode does not always meet this condition. How to manage the group keys to support the scenario of the cloud storage with a semi-trusted cloud server is still a challenging task. Moreover, the cloud storage system is a large-scale and open application, in which the user group is dynamic. To address this problem, we propose a practical group key management algorithm based on a proxy re-encryption mechanism in this paper. We use the cloud server to act as a proxy tore-encrypt the group key to allow authorized users to decrypt and get the group key by their private key. To achieve the hierarchical access control policy, our scheme enables the cloud server to convert the encrypted group key of the lower group to the upper group. The numerical analysis and experimental results further validate the high efficiency and security of the proposed scheme.

关键词： proxy re-encryption group key management bilinear map encrypted cloud storage

Polyfluorene based conjugated polymer nanoparticles for two-photon live cell imaging

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Science China Chemistry 2018年第1期61卷 88-96页

作者： Shuang Li Xiao-Fang Jiang qing-hua Xu Institute of Polymer optoelectronic Materials and Devices State Key Laboratory of Luminescent Materials and Devices South China University of Technology Guangzhou 510640 China National University of Singapore (Suzhou) Research Institute Suzhou 215123 China Department of Chemistry National University of Singapore Singapore 117543 Singapore

Two-photon excitation microscopy(2 PEM) has been known as a noninvasive and powerful bio-imaging tool for studying living cells, intact tissues and living animals because of their unique advantages such as localized excitation, deep tissue penetration as well as less photo-damage. However, the major limitations that hinder its practical applications in biological systems are low two-photon absorption cross sections of conventional fluorescence probes. Conjugated polymer nanoparticles(CPNs) consisting of highly fluorescent conjugated polymers are promising fluorescent probes for 2 PEM due to their unique advantages including large two-photon absorption cross sections, high fluorescence quantum yield, good photo-stability and biocompatibility, facile chemical synthesis, tunable optical properties as well as versatile surface modifications. This account summarizes the recent efforts of our group on development of novel polyfluorene based CPNs as 2 PEM contrast agents for live cell imaging.

关键词： conjugated polymers nanoparticles two-photon absorption fluorescence microscopy bio-imaging

FUNDAMENTAL SOLUTION BASED GRADED ELEMENT MODEL FOR STEADY-STATE HEAT TRANSFER IN FGM

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Acta Mechanica Solida Sinica 2012年第4期25卷 377-392页

作者： Leilei Cao Hui Wang qing-hua Qi Key Laboratory for Highway Construction Technology and Equipment of Ministry of Education Chang'an University Xi'an 710064 China School of Engineering Australian National University canberra ACT 0200 Australia College of Civil Engineering and Architecture Henan University of Technology Zhengzhou 450052 China

A novel hybrid graded element model is developed in this paper for investigating thermal behavior of functionally graded materials （FGMs）. The model can handle a spatially varying material property field of FGMs. In the proposed approach, a new variational functional is first constructed for generating corresponding finite element model. Then, a graded element is formulated based on two sets of independent temperature fields. One is known as intra-element temperature field defined within the element domain; the other is the so-called frame field defined on the element boundary only. The intra-element temperature field is constructed using the linear combination of fundamental solutions, while the independent frame field is separately used as the boundary interpolation functions of the element to ensure the field continuity over the interelement boundary. Due to the properties of fundamental solutions, the domain integrals appearing in the variational functional can be converted into boundary integrals which can significantly simplify the calculation of generalized element stiffness matrix. The proposed model can simulate the graded material properties naturally due to the use of the graded element in the finite element （FE） model. Moreover, it inherits all the advantages of the hybrid Trefftz finite element method （HT-FEM） over the conventional FEM and boundary element method （BEM）. Finally, several examples are presented to assess the performance of the proposed method, and the obtained numerical results show a good numerical accuracy.

关键词： graded element hybrid FEM heat conduction functionally graded materials

Event-based Control and Filtering of Networked Systems:A Survey

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International Journal of Automation and computing 2017年第3期14卷 239-253页

作者： Lei zou Zi-Dong Wang Dong-hua Zhou College of Electrical Engineering and Automation Shandong University of Science and Technology Department of Computer Science Brunel University London Department of Automation Tsinghua National Laboratory for Information Science and TechnologyTsinghua University

In recent years, theoretical and practical research on event-based communication strategies has gained considerable research attention due primarily to their irreplaceable superiority in resource-constrained systems（especially networked systems）. For networked systems, event-based transmission scheme is capable of improving the efficiency in resource utilization and prolonging the lifetime of the network components compared with the widely adopted periodic transmission scheme. As such, it would be interesting to 1） examining how the event-triggering mechanisms affect the control or filtering performance for networked systems, and 2） developing some suitable approaches for the controller and filter design problems. In this paper, a bibliographical review is presented on event-based control and filtering problems for various networked systems. First, the event-driven communication scheme is introduced in detail according to its engineering background, characteristic, and representative research frameworks. Then, different event-based control and filtering（or state estimation） problems are categorized and then discussed. Finally, we conclude the paper by outlining future research challenges for event-based networked systems.

关键词： Event-triggered transmission networked systems event-based control event-based filtering event-triggered distributed state estimation distributed control with event-based protocol