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Solutions for Toda System on Riemann Surface with Boundary

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Acta Mathematica Sinica,English Series 2011年第8期27卷 1501-1520页

作者： Xiao bao zhu Institute of Mathematics Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100190 P. R. China

In this paper, we study the solutions for Toda system on Riemann surface with boundary. We prove a sufficient condition for the existence of solution of Toda system in the critical case.

关键词： Toda system Riemann surface with boundary

The regulatory sciences for stem cell-based medicinal products

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Frontiers of Medicine 2014年第2期8卷 190-200页

作者： bao-zhu Yuan JunzhiWang National Institutes for Food and Drug Control Beijing 100050 China

Over the past few years, several new achievements have been made from stem cell studies, many of which have moved up from preclinical stages to early, or from early to middle or late, stages thanks to relatively safe profile and preliminary evidence of effectiveness. Moreover, some stem cell-based products have been approved for marketing by different national regulatory authorities. However, many critical issues associated mainly with incomplete understanding of stem cell biology and the relevant risk factors, and lack of effective regulations still exist and need to be urgently addressed, especially in countries where establishment of appropriate regulatory system just commenced. More relevantly, the stem cell regulatory sciences need to be established or improved to more effectively evaluate quality, safety and efficacy of stem cell products, and for building up the appropriate regulatory framework. In this review, we summarize some new achievements in stem cell studies, especially the preclinical and clinical studies, the existing regulations, and the associated challenges, and we then propose some considerations for improving stem cell regulatory sciences with a goal of promoting the steadfast growth of the well-regulated stem cell therapies abreast of evolvement of stem cell sciences and technologies.

关键词： stem cell-based medicinal products (SCMPs) stem cell therapy (SCT) safety effectiveness standards guidelines regulatory science

On Real-rootedness of Independence Polynomials of Rooted Products of Graphs

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Acta Mathematicae Applicatae Sinica 2023年第4期39卷 854-867页

作者： Aria Ming-yue zhu bao-xuan zhu School of Mathematics and Statistics Jiangsu Normal UniversityXuzhou 221116China

An independent set in a graph G is a set of pairwise non-adjacent vertices. The independence polynomial of G is the polynomial AΣx^(|A|), where the sum is over all independent sets A of G. In 1987, Alavi,Malde, Schwenk and Erd os conjectured that the independence polynomial of any tree or forest is *** this unimodality conjecture has attracted many researchers’ attention, it is still open. Recently, Basit and Galvin even asked a much stronger question whether the independence polynomial of every tree is ordered log-concave. Note that if a polynomial has only negative real zeros then it is ordered log-concave and *** this paper, we observe real-rootedness of independence polynomials of rooted products of graphs. We find some trees whose rooted product preserves real-rootedness of independence polynomials. In consequence, starting from any graph whose independence polynomial has only real zeros, we can obtain an infinite family of graphs whose independence polynomials have only real zeros. In particular, applying it to trees or forests, we obtain that their independence polynomials are unimodal and ordered log-concave.

关键词： independence polynomials unimodality real zeros rooted products claw-free graphs

Numerical Solution to Optimal Feedback Control by Dynamic Programming Approach:A Local Approximation Algorithm

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Journal of Systems Science & Complexity 2017年第4期30卷 782-802页

作者： GUO bao-zhu WU Tao-Tao Academy of Mathematics and Systems Science Chinese Academy of Sciences School of Mathematical Sciences University of Chinese Academy of Sciences

This paper considers optimal feedback control for a general continuous time finite-dimensional deterministic system with finite horizon cost functional. A practically feasible algorithm to calculate the numerical solution of the optimal feedback control by dynamic programming approach is developed. The highlights of this algorithm are: a) It is based on a convergent constructive algorithm for optimal feedback control law which was proposed by the authors before through an approximation for the viscosity solution of the time-space discretization scheme developed by dynamic programming method; b) The computation complexity is significantly reduced since only values of viscosity solution on some local cones around the optimal trajectory are calculated. Two numerical experiments are presented to illustrate the effectiveness and fastness of the algorithm.

关键词： Curse of dimensionality Hamilton-Jacobi-Bellman equation optimal feedback control upwind finite difference viscosity solutions

ON NODAL LINE OF THE SECOND EIGENFUNCTION OF THE LAPLACIAN OVER CONCAVE DOMAINS IN R^2

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Journal of Systems Science & Complexity 2013年第3期26卷 483-488页

作者： YANG Dong-Hui Guo bao-zhu Department of Mathematics Central South University Academy of Mathematics and Systems Science Academia Sinica

In this note,the Payne's conjecture from convex domains to concave domains is *** is shown that the nodal line N of the second eigenfunction of the Laplacian over some simply connected concave domain Ω in R^2 must in... 详细信息

关键词： Eigenfunction eigenvalue Laplacian.

Determination of trace inorganic anions in anionic surfactants by single-pump column-switching ion chromatography

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Chinese Chemical Letters 2012年第7期23卷 835-838页

作者： Jia Jie Zhang Hai bao zhu Yan zhu Department of Chemistry Zhejiang UniversityHangzhou 310028China Zhejiang Academy of Medical Sciences Hangzhou 310013China

An ion chromatography method has been proposed for the determination of three common inorganic anions（chloride,nitrate and sulfate） in anionic surfactants using a single pump *** new system consists of an ion exclusion column,a concentrator column,and an anion exchange column connected in series via two 6-ports valves in a Dionex ICS-2000 ion *** valves were switched several times for removing surfactants,concentrating and separating the three *** chromatographic conditions were *** limits（S/N = 3） were in the range of 0.10-0.68μg/*** relative standard deviations（RSDs） of peak area were less than 4.6%.The recoveries were in the range of 84.1-112.6%.

关键词： Anionic surfactants Single pump Column-switching

Estimated Average Glandular Dose for 1,828 Mammography Procedures in China: A Multicenter Study

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Biomedical and Environmental Sciences 2019年第4期32卷 242-249页

作者： DU Xiang WANG Jin zhu bao Li Jiangsu Provincial Center for Disease Prevention and Control Center for Global Health School of Public HealthNanjing Medical University

Objective To understand the distribution of the average glandular dose(AGD) in mammography by investigating 1,828 exposure parameters of 8 mammography machines in three cities, by using random sampling. Methods A survey of 8 mammography machines in three different cities, sampled using stratified random sampling methods, was performed, and 1,828 mammography exposure parameters were recorded. Incident air kerma(k) was measured by Quality-Assurance(QA) dosimeters, and AGD was calculated by series conversion coefficients based on a 3D detailed Monte Carlo breast model, published by Wang et al. Results The distribution of compressed breast thickness(CBT) fitted a normal distribution, while that of AGD fitted a skewed distribution. The mean value of CBT in a medio-lateral oblique(MLO) view was about 5.6% higher than that in the craniocaudal(CC) view, with significant statistical difference; mean value of AGD and CBT in the sample was 1.3 mGy and 4.6 cm, respectively. The AGD trended upward with increasing CBT, similar to the results of other researches. Conclusion The mean AGD and CBT levels in our study for mammography practice in China were 1.3 mGy and 4.6 cm, respectively. AGD is influenced by manufacturer-specific variation as machine response to CBT changes and target/filter combination. The present study can provide evidence for establishing a diagnostic reference level in China.

关键词： Medical radiation Mammography Compressed breast thickness Average glandular dose

Comparison and assessment of time integration algorithms for nonlinear vibration systems

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Journal of Central South University 2017年第5期24卷 1090-1097页

作者： YANG Chao YANG bao-zhu zhu Tao XIAO Shou-ne State Key Laboratory of Traction Power Southwest Jiaotong University School of Mechanical Electronic and Control Engineering Beijing Jiaotong University

A corrected explicit method of double time steps(CEMDTS) was introduced to accurately simulate nonlinear vibration problems in engineering. The CEMDTS, the leapfrog central difference method, the Newmark method, the generalized-a method and the precise integration method were implemented in typical nonlinear examples for the purpose of comparison. Both conservative and non-conservative systems were examined. The results show that it isn't unconditionally stable for the precise integration method, the Newmark method and the generalized-a method in nonlinear systems. The stable interval of the three methods is less than that of the CEMDTS. When a small time step(?t≤T_(min)/20) is employed, the precise integration method is endowed with the highest accuracy while the CEMDTS possesses the smallest computation effort. However, the CEMDTS becomes the most accurate one when the time step is large(?t≥0.3T_(min)) or the system is strongly nonlinear. Therefore, the CEMDTS is more applicable to the nonlinear vibration systems.

关键词： nonlinear vibration conservative system explicit algorithm accuracy

Floquet topological phase transition in two-dimensional quadratic band crossing system

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Chinese Physics B 2021年第6期30卷 521-525页

作者： Guo-bao zhu Hui-Min Yang School of Physics and Electronic Engineering Heze UniversityHeze 274015China

We investigate the Hall effects of quadratic band crossing(QBC) fermions in a square optical lattice with spin–orbit coupling and orbital Zeeman term. We find that the orbital Zeeman term and shaking play critical roles in the systems,which can drive a topological transition from spin Hall phases to anomalous Hall phase with nonvanishing(spin) Chern numbers. Due to the interplay among the orbital Zeeman term, spin–orbit coupling, and the shaking, the phase diagram of the system exhibits rich phases, which are characterized by Chern number.

关键词： shaking quadratic band crossing orbital