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A quadratic programming method for optimal degree reduction of Bézier curves with G^1-continuity

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第10期8卷 1657-1662页

作者： lu Li-zheng WANG Guo-zhao Institute of Computer Graphics and lmage Processing Department of Mathematics Zhejiang University Hangzhou 310027 China

This paper presents a quadratic programming method for optimal multi-degree reduction of B6zier curves with G^1-continuity. The L2 and I2 measures of distances between the two curves are used as the objective functions. The two additional parameters, available from the coincidence of the oriented tangents, are constrained to be positive so as to satisfy the solvability condition. Finally, degree reduction is changed to solve a quadratic problem of two parameters with linear constraints. Applications of degree reduction of Bezier curves with their parameterizations close to arc-length parameterizations are also discussed.

关键词： Degree reduction Bezier curves Optimal approximation G^1-continuity Quadratic programming

Experimental Investigation of a Nonlinear Damper System

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Experimental Investigation of a Nonlinear Damper System

Design,synthesis and evaluation of spermine-based pH-sensitive amphiphilic gene delivery systems: Multifunctional non-viral gene carriers

第25届中国控制与决策会议

作者： lu zheng Research Institute of Structural Engineering and Disaster Reduction Tongji University

ISBN: (纸本)9781467355339

An experimental investigation of the performance of a nonlinear damper system is presented. The nonlinear system is composed of a multi unit particle damper and a multi-degree-of-freedom structure. A series of shaking table tests are carried out to characterize this nonlinear system and to evaluate the vibration control effects of particle dampers. The experimental results indicate that the primary structure with particle dampers has smaller response compared with that of the structure without particle dampers;that the excitation characterization influences the performance of such a nonlinear system;and that the particle movements of plug flow pattern can yield good vibration attenuation effects. It is shown that by using a properly designed multi-unit particle dampers, a lightly damped primary system can achieve a reasonable reduction in its response, with a small weight penalty.

关键词： Nonlinear system vibration control particle damper impact damper shaking table test

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Science China Chemistry 2011年第2期54卷 359-368页

作者： XU RongZuo lu zheng-Rong Departments of Pharmaceutics and Pharmaceutical Chemistry University of Utah Salt Lake City Utah 84108 USA Department of Biomedical Engineering Case Western Reserve University Cleveland OH 44106 USA

Design and development of efficient non-viral gene delivery systems is critical to overcome various barriers for effective intracellular gene *** new spermine-based protonatable surfactants were designed,synthesized and evaluated as non-viral pH-sensitive gene *** carriers formed stable complexes with plasmid DNA at an N/P ratio as low as *** sizes of the carrier/pDNA nanoparticles (N/P = 12) were in the range of 90–130 nm,smaller than that of Lipofectamine2000/pDNA *** pDNA nanoparticles of the carriers exhibited substantially increased hemolysis when pH decreased from 7.4 to *** DNA nanoparticles had low cytotocixity,similar to that of Lipofectamine-2000/pDNA *** pH-sensitive gene carriers with no helper lipids resulted in much higher intracellular transfection and gene expression in U87 cells than Lipofectamine-2000.[N,N′-Bis(oleoylcysteinyl)(β-alanyl-α-lysyl)]-spermine monoamide (SKACO) resulted in the highest luciferase transfection efficiency,more than 400 times higher than that of Lipofectamine-2000,and GFP expression in 71% of transfected U87 *** was identified as a promising lead carrier for efficient gene *** spermine-based pH-sensitive amphiphilic carriers have a potential to be further developed as efficient non-viral multifunctional gene delivery systems.

关键词： gene delivery plasmid DNA pH sensitive multifunctional

Convergence of a Non-interior Continuation Algorithm for the Monotone SCCP

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Acta Mathematicae Applicatae Sinica 2010年第4期26卷 543-556页

作者： Nan lu zheng-Hai Huang Department of Mathematics School of ScienceTianjin UniversityTianjin 300072China

It is well known that the symmetric cone complementarity problem（SCCP） is a broad class of optimization problems which contains many optimization problems as special *** on a general smoothing function,we propose in this paper a non-interior continuation algorithm for solving the monotone *** proposed algorithm solves at most one system of linear equations at each *** using the theory of Euclidean Jordan algebras,we show that the algorithm is globally linearly and locally quadratically convergent under suitable assumptions.

关键词： Symmetric cone complementarity problem non-interior continuation method global linear convergence local quadratic convergence

Explicit G2-constrained Merging of a Pair of Bezier Curves by Control Point Optimization

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自动化学报 2014年第7期40卷 1505-1508页

作者： lu Li-zheng QIU Yu-Yang School of Statistics and Mathematics Zhejiang Gongshang University Hangzhou 310018 China

This paper presents a simple and explicit method for G~2-constrained merging of a pair of Bezier curves by minimizing the l_2 distance defined in terms of control points. After expressing the l_2 distance as a quadratic function of two parameters, the optimally merged curve can be explicitly obtained, which is achieved by control point optimization such that the l_2 distance is minimized. The existence of the unique solution is shown by proving that the l_2 distance is convex. The proposed method is explicit and efficient since it is non-iterative and expressed by known control points. Numerical examples demonstrate the effectiveness of the new method.

关键词：贝塞尔曲线控制点合并 G2 优化二次函数距离最小化

Influence of Narrative Strategies on Fundraising Outcome:An Exploratory Study of Online Medical Crowdfunding

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Journal of Social Computing 2022年第4期3卷 303-321页

作者： lu zheng Lihui Jiang Department of Sociology Tsinghua UniversityBeijing 100084China

Online medical crowdfunding(OMC)has attracted massive attention and participation in *** its goal to lift the financial burden caused by expensive medical expenditure,little has been done to evaluate its impact on healthcare *** examine the social consequences of OMC based on a large random sample extracted from one of the most widely-used OMC platforms in *** analysis shows that a disproportionally high percentage of fundraising campaigns are launched for patients with low socioeconomic status suffering from various illnesses,including many rare *** findings suggest that OMC plays a positive role in providing an alternative channel for disadvantaged patients under the current health insurance *** further examine whether and the extent to which the narrative style of solicitation text—fundraising campaign description—influences fundraising outcomes using natural language processing(NLP).The results show that expressions conveying optimism tend to result in a higher completion ratio,whereas descriptions engaging in moral mobilization or focusing on financial burden tend to have a negative impact on fundraising outcomes.

关键词： online medical crowdfunding(OMC) narrative fundraising outcome healthcare inequality

Preparation of Al2O3/Y2O3 composite coating for deuterium permeation reduction

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Journal of Rare Earths 2020年第11期38卷 1237-1242,I0004页

作者： Weijing Wang Qinghe Yu Xiaopeng Liu zheng lu National Engineering Research Center of Nonferrous Metals Materials and Products for New Energy GRINM Group Co.Ltd.Beijing 100088China GRIMAT Engineering Institute Co. Ltd.Beijing 101407China General Research Institute for Nonferrous Metals Beijing 100088China School of Materials Science and Engineering Northeastern UniversityShenyang 110819China

A tritium permeation barrier is required in fusion blankets for the reduction of fuel loss and radiological *** this study,an Al2O3/Y2O3 composite coating was prepared on 316 L stainless steel by radiofrequency magnetron sputtering in order to improve the tritium permeation *** microstructure and the phase composition of the Al2O3/Y2O3 composite coating are observed by scanning electron microscopy,transmission electron microscopy and grazing incidence X-ray ***,Auger electron spectroscopy was used to characterize the depth profiles of Al,Y and O *** results clearly indicate that the Al2O3/Y2O3 composite coating is fully dense and the total thickness is approximately 340 *** Al2O3/Y2O3 coating consists of an amorphous Al2O3 and the cubic Y2O3,in which Al,Y and O elements are homogeneously distributed in the vertical base ***,the deuterium permeation property of the Al2O3/Y2O3 composite coating was measured by the gas phase permeation *** results show that the introduction of an interface and the existence of a tiny amount of micro-defects improve the deuterium resistance of the Al2O3/Y2O3 coating,and its deuterium permeation reduction factor is 536-750 at 873-973 ***,it is concluded that the Al2O3/Y2O3 co mposite coating as deuterium permeation barrier can significa ntly enha nce the deuterium permeation resistance property.

关键词： Deuterium Permeation barrier Al2O3 coating Y2O3 coating Composite coating Rare earths

Recent progress of flexible electronics by 2D transition metal dichalcogenides

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Nano Research 2022年第3期15卷 2413-2432页

作者： lu zheng Xuewen Wang Hanjun Jiang Manzhang Xu Wei Huang zheng Liu Frontiers Science Center for Flexible Electronics(FSCFE)&Shaanxi Institute of Flexible Electronics(SIFE) Northwestern Polytechnical UniversityXi’an 710072China Shaanxi Key Laboratory of Flexible Electronics(KLoFE) Northwestern Polytechnical UniversityXi’an 710072China School of Materials Science and Engineering Nanyang Technological University50 Nanyang AvenueSingapore 639798Singapore

Flexible electronics is the research field with interdisciplinary crossing and *** shows the promising advantages of novel device configurations,low-cost and low-power consumption due to their flexible and soft *** layered two-dimensional(2D)materials especially transition metal dichalcogenides,have triggered great interest in ultra-thin 2D flexible electronic devices and optoelectronic devices because of their direct and tunable bandgaps,excellent electrical,optical,mechanical,and thermal *** review aims to provide the recent progress in 2D TMDs and their applications in flexible *** fundamental electrical properties and mechanical properties of materials,flexible device configurations,and their performance in transistors,sensors,and photodetectors are thoroughly *** last,some perspectives are given on the open challenges and prospects for 2D TMDs flexible electronic devices and new device opportunities.

关键词： two-dimensional materials flexible electronics flexible transistors flexible sensors

A Convenient Heterogeneous Reduction of Knoevenagel Product by Hantzsch Ester and Its Development into Reductive Alkylation of Malononitrile

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Chinese Journal of Chemistry 2014年第7期32卷 650-653页

作者： Yong-Qing Yang zheng lu School of Pharmacy Jiangsu UniversityZhenjiangJiangsu 212013China

Poor solubility of Hantzsch ester is used as indicator in the reduction of methylidene *** Knoevenagel reaction is integrated to develop a reductive alkylation of malononitrile with aryl and aliphatic aldehyde as the ... 详细信息

关键词： heterogeneous reduction Hantzsch ester Knoevenagel condensation reductive alkylation