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Sufficient conditions for stability of linear time-delay systems with dependent delays

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Journal of Systems Engineering and Electronics 2013年第5期24卷 845-851页

作者： ying.zhu Qina Gao Yang Xiao School of Electronic and Information Engineering Beihang University Beijing Aeronautical Technology Research Center Institute of Information Science Beijing Jiaotong University

According to the delay property, linear time-delay （LTD） systems can be classified as LTD systems with depen- dent delays （LTD_DD） and LTD systems with independent delays （LTD_ID）. This paper reveals that the stability condition for LTD_ID systems can be applied to LTD_DD systems, a sufficient stability condition for LTD_DD systems is derived from it, while only fewer of the LTD_DD systems can satisfy the stability condition due to the very strict limitation for the delays of the LTD_DD systems. To solve the problem, based on two-dimensional （2-D） hybrid polynomials, some sufficient conditions for stability of LTD_DD systems are pro- posed. Examples show that the proposed stability test algorithms are simple and valid.

关键词： time-delay systems auasipolvnomials stabilitv test

Algorithm for complex network diameter based on distance matrix

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Journal of Systems Engineering and Electronics 2018年第2期29卷 336-342页

作者： CHEN Bin zhu Weixing LIU ying Institute of Command Information System PLA University of Science and Technology College of Computer Science and Engineering Sanjiang University Institute of Field Engineering PLA University of Science and Technology

The network diameter is an important characteristic parameter of a complex network. Calculation for a large-scale complex network’s diameter has been an important subject in the study of complex networks. If the network diameter is calculated directly, the problem mainly exists in efficiency for searching and counting the shortest paths. If the network diameter is calculated indirectly by studying the statistical function about the relationship between the network diameter and parameters affecting the diameter, the problems not only exist in the efficiency of statistic, but also exist in the function which may be not applicable to all kinds of networks. An algorithm for the complex network diameter based on the k order distance matrix is proposed with a matrix multiplication approach, and a mathematical proof for the algorithm correctness is given as well. Furthermore, some relevant propositions and deductions for reducing the complexity of this algorithm are put forward. With a good theoretical basis and a simple calculation process, this algorithm can be used to calculate the diameter of a large-scale complex network with small-world effect more accurately and efficiently. Two cases about the advanced research projects agency(ARPA) network model and the Chinese airline network model are adopted to verify the effect of this algorithm.

关键词： complex network network diameter distance matrix

Two-dimensional Hurwitz-Schur stability test of linear systems with interval delays

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Journal of Systems Engineering and Electronics 2013年第4期24卷 666-673页

作者： Qina Gao ying.zhu Yang Xiao School of Electronic and Information Engineering Beihang University Beijing Aeronautical Technology Research Center Institute of Information Science Beijing Jiaotong University

It is difficult to determine the stability of linear systems with interval delays （LID systems） because the roots of the characteristic polynomials of the systems are continuous and vary in a complex plane with the delay. To solve the problem, this paper develops a stability test of LID systems by resorting to 2-D hybrid polynomials and 2-D Hurwitz-Schur stability. Comparing with the existing test approaches for LID systems, the proposed 2-D Hurwitz-Schur stability test is easy to apply, and can obtain closed form constraint conditions for system parameters. This paper proposes some theorems as sufficient conditions for the stability of LID systems, and also reveals that recent results about the stability test of linear systems with any delays （LAD systems） are not suitable for LID systems because they are very conservative for the stability of LID systems.

关键词： time-delay system quasipolynomial stability test 2-D Hurwitz-Schur stability.

Multivariate time delay analysis based local KPCA fault prognosis approach for nonlinear processes

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Chinese Journal of Chemical Engineering 2016年第10期24卷 1413-1422页

作者： Yuan Xu ying Liu Qunxiong zhu College of Information Science and Technology Beijing University of Chemical Technology

Currently, some fault prognosis technology occasionally has relatively unsatisfied performance especially for in- cipient faults in nonlinear processes duo to their large time delay and complex internal connection. To overcome this deficiency, multivariate time delay analysis is incorporated into the high sensitive local kernel principal component analysis. In this approach, mutual information estimation and Bayesian information criterion （BIC） are separately used to acquire the correlation degree and time delay of the process variables. Moreover, in order to achieve prediction, time series prediction by back propagation （BP） network is applied whose input is multivar- iate correlated time series other than the original time series. Then the multivariate time delayed series and future values obtained by time series prediction are combined to construct the input of local kernel principal component analysis （LKPCA） model for incipient fault prognosis. The new method has been exemplified in a sim- ple nonlinear process and the complicated Tennessee Eastman （TE） benchmark process. The results indicate that the new method has suoerioritv in the fault prognosis sensitivity over other traditional fault prognosis methods.

关键词： Fault prognosis Time delay estimation Local kernel principal component analysis

卷曲螺旋结构域蛋白2通过促进线粒体自噬抑制帕金森病SH-SY5Y细胞凋亡

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中国组织工程研究 2025年第25期29卷 5403-5413页

作者：祝柳慧张歆悦朱洲海杨兴隆管莹刘彬昆明医科大学第一附属医院神经内科云南省昆明市650032 烟草与健康联合研究院云南省昆明市650106

背景:卷曲螺旋结构域蛋白2(coiled-coil-helix-coiled-coil-helix domain-containing 2,CHCHD2)能否调控PINK1/Parkin介导的线粒体自噬在帕金森病中发挥神经保护作用尚未可知。目的:探讨CHCHD2在6-羟基多巴胺诱导的帕金森病细胞模型中对PINK1/Parkin信号通路介导的线粒体自噬发挥的作用及机制。方法:利用重组质粒转染技术过表达或敲低CHCHD2,用6-羟基多巴胺构建SH-SY5Y细胞帕金森病模型后分对照组、模型组、过表达阴性对照+6-羟基多巴胺组、敲低阴性对照+6-羟基多巴胺组、过表达CHCHD2+6-羟基多巴胺组和敲低CHCHD2+6-羟基多巴胺组。Western blot及RT-qPCR检测CHCHD2的表达;Western blot检测LC3Ⅰ/Ⅱ、p62、MFN1、COXⅣ、DRP1、PINK1、Parkin、TIM23、Bax、Bcl-2及cleavedcaspase3蛋白表达;CCK-8、JC-1和活性氧试剂盒检测细胞活性、线粒体膜电位和活性氧水平,单丹磺酰尸胺染色观察细胞自噬情况,透射电镜观察自噬溶酶体。结果与结论:①与对照组相比,模型组细胞活性、线粒体膜电位及CHCHD2、PINK1、Parkin蛋白表达降低,活性氧水平、凋亡水平及LC3Ⅰ/Ⅱ、p62蛋白表达升高(P<0.05),并观察到自噬溶酶体的存在;②与模型组相比,过表达CHCHD2能降低细胞活性氧水平,升高线粒体膜电位及PINK1、Parkin和MFN1蛋白表达水平,并观察到线粒体自噬溶酶体增多,而敲低CHCHD2后有与上述相反的作用,并伴有COXⅣ、TIM23和p-DRP1蛋白表达的升高(P<0.05);③与模型组相比,过表达CHCHD2能减少细胞凋亡,上调Bcl-2并下调Bax及cleavedcaspase3蛋白的表达,而敲低CHCHD2后有与上述相反的作用(P<0.05);④结果提示,CHCHD2在6-羟基多巴胺诱导的帕金森病细胞模型中可以通过促进PINK1/Parkin介导的线粒体自噬改善线粒体功能从而减轻细胞凋亡发挥神经保护作用。

关键词：帕金森病卷曲螺旋结构域蛋白2 PINK1 Parkin 线粒体自噬线粒体功能细胞凋亡 6-羟基多巴胺 SH-SY5Y细胞

A NON-LINEAR MODEL FOR ESTIMATING THE COST OF ACHIEVING EMISSION REDUCTION TARGETS:THE CASE OF THE U.S.,CHINA AND INDIA

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Journal of Systems Science and Systems Engineering 2012年第3期21卷 297-315页

作者： Lei zhu Xiao-Bing ZHANG ying FAN Center for Energy & Environmental Policy Research Institute of Policy and Management Chinese Academy of Sciences Beijing 100190 China Department of Economics University of Gothenburg SE 40530 G teborg Sweden

With the world talking about climate change, the United States （U.S.）, China and India have announced their carbon emission reduction targets. For these three countries to achieve their targets, significant questions arise, shch as what will be the annual emission reduction efforts to achieve those targets, how much it would cost and what would be the economic effects. This paper puts the carbon intensity reduction targets of China and India together with the absolute emission reduction target of the U.S. into the same non-linear model to quantitatively study the optimal emission control strategies and associated total cost for achieving those targets by the year 2020, and estimate and compare the minimized total costs of the three countries to reach their targets. Our results show that the total cost for the U.S. to achieve its emission reduction target is greater than those of China and India in terms of absolute amount. However, in terms of proportion of total cost to GDP, China and India＇s ratios are significantly greater than that of the U.S., indicating that for the developing countries such as China and India, the achievement of emission reduction targets needs relatively greater effort.

关键词： Emission reduction cost analysis emission reduction strategy optimization model

Progress on Regulation of NLRP3 Inflammasome by Chinese Medicine in Treatment of Ulcerative Colitis

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Chinese Journal of Integrative Medicine 2023年第8期29卷 750-760页

作者： SUN Hao-xian zhu ying Department of Gastroenterology the First Affiliated Hospital of Hunan University of Chinese MedicineChangsha(410007)China Hunan University of Chinese Medicine Changsha(410208)China

Ulcerative colitis(UC)is a chronic,non-specific intestinal disease that not only affects the quality of life of patients and their families but also increases the risk of colorectal *** nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing protein 3(NLRP3)inflammasome is an important component of inflammatory response system,and its activation induces an inflammatory cascade response that is involved in the development and progression of UC by releasing inflammatory cytokines,damaging intestinal epithelial cells,and disrupting the intestinal mucosal *** medicine(CM)plays a vital role in the prevention and treatment of UC and is able to regulate NLRP3 *** experimental studies on the regulation of NLRP3 inflammasome mediated by CM have been carried out,demonstrating that CM formulae with main effects of clearing heat,detoxifying toxicity,drying dampness,and activating blood *** and phenylpropanoids can effectively regulate NLRP3 *** active components of CM can interfere with the process of NLRP3 inflammasome assembly and activation,leading to a reduction in inflammation and UC ***,the reports are relatively scattered and lack systematic *** paper reviews the latest findings regarding the NLRP3 inflammasome activation-related pathways associated with UC and the potential of CM in treating UC through modulation of NLRP3 *** purpose of this review is to explore the possible pathological mechanisms of UC and suggest new directions for development of therapeutic tools.

关键词： NLRP3 inflammasome ulcerative colitis Chinese medicine mechanism of action review

Homoclinic and Periodic Orbits Arising Near the Heteroclinic Cycle Connecting Saddle-focus and Saddle Under Reversible Condition

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Acta Mathematica Sinica,English Series 2007年第8期23卷 1495-1504页

作者： De Ming zhu ying SUN Department of Mathematics East China Normal University Shanghai 200062 P. R. China School of Science University of Ji'nan Ji'nan 250022 P. R. China

In this paper, we study the dynamical behavior for a 4-dimensional reversible system near its heteroclinic loop connecting a saddle-focus and a saddle. The existence of infinitely many reversible 1-homoclinic orbits to the saddle and 2-homoclinic orbits to the saddle-focus is shown. And it is also proved that, corresponding to each 1-homoclinic （resp. 2-homoclinic） orbit F, there is a spiral segment such that the associated orbits starting from the segment are all reversible 1-periodic （resp. 2-periodic） and accumulate onto F. Moreover, each 2-homoclinic orbit may be also accumulated by a sequence of reversible 4-homoclinic orbits.

关键词： reversible condition homoclinic orbit Poincare map periodic orbit saddle-focus

Machine learning potential aided structure search for low-lying candidates of Au clusters

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Chinese Physics B 2022年第7期31卷 613-619页

作者： Tonghe ying Jianbao zhu Wenguang zhu Department of Physics University of Science and Technology of Chinaand Key Laboratory of Strongly-Coupled Quantum Matter PhysicsChinese Academy of SciencesHefei 230026China International Center for Quantum Design of Functional Materials(ICQD) Hefei National Laboratory for Physical Sciences at the Microscaleand Synergetic Innovation Center of Quantum Information and Quantum PhysicsUniversity of Science and Technology of ChinaHefei 230026China

A machine learning(ML)potential for Au clusters is developed through training on a dataset including several different sized *** ML potential accurately covers the whole configuration space of Au clusters in a broad size range,thus expressing a good performance in search of their global minimum energy *** on our potential,the low-lying structures of 17 different sized Au clusters are identified,which shows that small sized Au clusters tend to form planar structures while large ones are more likely to be stereo,revealing the critical size for the two-dimensional(2D)to three-dimensional(3D)structural *** calculations demonstrate that ML is indeed powerful in describing the interaction of Au atoms and provides a new paradigm on accelerating the search of structures.

关键词： machine learning potential gold cluster first-principles calculation