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2044篇 您的检索式:作者名="Lixin"
    题名 作者 年代 出处 被引量
1CONVERGENCERATESIN THESTRONG LAWSOFASYMPTOTICALLY NEGATIVELY ASSOCIATEDRANDOM FIELDS显示文摘In this paper, a notion of negative side ρ \|mixing ( ρ\+- \|mixing) which can be regarded as asymptotic negative association is defined, and some Rosenthal type inequalities for ρ\+- \|mixing random fields are established. The complete convergence and almost sure summability on the convergence rates with respect to the strong law of large numbers are also discussed for ρ\+-\| mixing random fields. The results obtained extend those for negatively associated sequences and ρ\+*\| mixing random fields.Zhang Lixin\ Wang Xiuyun 1999Applied Mathematics(A Journal of Chinese Universities)1999,14,4:52
2SHRIMP zircon U-Pb dating for subduction-related gran-itic rocks in the northern part of east Junggar, Xinjiang显示文摘SHRIMP U-Pb zircon dating on the Xileketehalasu granodiorite porphyry and Kalasayi monodiorite porphyry that intrude middle Devonian Beitashan Formation at the north part of east Junggar region shows that they were formed at 381±6 Ma and 376±10 Ma respectively. They are interpreted as subduction-related granitic rocks, which is the first report that the isotopic ages for the granitic rocks range from 350 to 390 Ma. Another determined age for the Kalasayi monodiorite porphyry is 408±9 Ma, representing the age of underlain Lower Devonian volcanic rocks. Thus, the U-Pb dates suggest that the northeastward subduction of Junggar ocean from southwest occurred at 408 to 376 Ma (the real inter- val may be larger). Because the ore-bearing porphyry intruded following the formation of the volcanic rocks of middle Devonian Beitashan Formation, their tec- tonic setting is similar to the Andes Mountains that hosts world-class porphyry copper deposits, and the researched area could be regarded as a potential area for prospecting large porphyry copper deposits.ZHANG Zhaochong YAN Shenghao CHEN Bailin ZHOU Gang HE Yongkang CHAI Fengmei HE Lixin WAN Yusheng 2006Chinese Science Bulletin2006,51,8:43
3Rosenthal's inequalities for independent and negatively dependent random variables under sub-linear expectations with applications显示文摘Classical Kolmogorov's and Rosenthal's inequalities for the maximum partial sums of random variables are basic tools for studying the strong laws of large numbers.In this paper,motived by the notion of independent and identically distributed random variables under the sub-linear expectation initiated by Peng(2008),we introduce the concept of negative dependence of random variables and establish Kolmogorov's and Rosenthal's inequalities for the maximum partial sums of negatively dependent random variables under the sub-linear expectations.As an application,we show that Kolmogorov's strong law of larger numbers holds for independent and identically distributed random variables under a continuous sub-linear expectation if and only if the corresponding Choquet integral is finite.ZHANG LiXin 2016Science China Mathematics2016,59,4:46
4Exponential inequalities under the sub-linear expectations with applications to laws of the iterated logarithm显示文摘Kolmogorov's exponential inequalities are basic tools for studying the strong limit theorems such as the classical laws of the iterated logarithm for both independent and dependent random variables. This paper establishes the Kolmogorov type exponential inequalities of the partial sums of independent random variables as well as negatively dependent random variables under the sub-linear expectations. As applications of the exponential inequalities, the laws of the iterated logarithm in the sense of non-additive capacities are proved for independent or negatively dependent identically distributed random variables with finite second order moments.For deriving a lower bound of an exponential inequality, a central limit theorem is also proved under the sublinear expectation for random variables with only finite variances.ZHANG LiXin 2016Science China Mathematics2016,59,12:38
5Developing the Science Product Algorithm Testbed for Chinese Next-Generation Geostationary Meteorological Satellites:Fengyun-4 Series显示文摘Fengyun-4A(FY-4A), the first of the Chinese next-generation geostationary meteorological satellites, launched in2016, offers several advances over the FY-2: more spectral bands, faster imaging, and infrared hyperspectral measurements. To support the major objective of developing the prototypes of FY-4 science algorithms, two science product algorithm testbeds for imagers and sounders have been developed by the scientists in the FY-4 Algorithm Working Group(AWG). Both testbeds, written in FORTRAN and C programming languages for Linux or UNIX systems, have been tested successfully by using Intel/g compilers. Some important FY-4 science products, including cloud mask, cloud properties, and temperature profiles, have been retrieved successfully through using a proxy imager, Himawari-8/Advanced Himawari Imager(AHI), and sounder data, obtained from the Atmospheric Infra Red Sounder, thus demonstrating their robustness. In addition, in early 2016, the FY-4 AWG was developed based on the imager testbed—a near real-time processing system for Himawari-8/AHI data for use by Chinese weather forecasters.Consequently, robust and flexible science product algorithm testbeds have provided essential and productive tools for popularizing FY-4 data and developing substantial improvements in FY-4 products.Min MIN Chunqiang WU Chuan LI Hui LIU Na XU Xiao WU Lin CHEN Fu WANG Fenglin SUN Danyu QIN Xi WANG Bo LI Zhaojun ZHENG Guangzhen CAO Lixin DONG 2017Journal of Meteorological Research2017,31,4:35
6Gain self-scheduled H_∞ control for morphing aircraft in the wing transition process based on an LPV model显示文摘This article investigates gain self-scheduled H 1 robust control system design for a tailless fold- ing-wing morphing aircraft in the wing shape varying process. During the wing morphing phase, the aircraft's dynamic response will be governed by time-varying aerodynamic forces and moments. Nonlinear dynamic equations of the morphing aircraft are linearized by using Jacobian linearization approach, and a linear parameter varying (LPV) model of the morphing aircraft in wing folding is obtained. A multi-loop controller for the morphing aircraft is formulated to guarantee stability for the wing shape transition process. The proposed controller uses a set of inner-loop gains to provide stability using classical techniques, whereas a gain self-scheduled H 1 outer-loop controller is devised to guarantee a specific level of robust stability and performance for the time-varying dynamics. The closed-loop simulations show that speed and altitude vary slightly during the whole wing folding process, and they converge rapidly after the process ends. This proves that the gain self-scheduled H 1 robust controller can guarantee a satisfactory dynamic performance for the morphing aircraft during the whole wing shape transition process. Finally, the flight control system's robustness for the wing folding process is verified according to uncertainties of the aerodynamic parameters in the nonlinear model.Yue Ting Wang Lixin Ai Junqiang 2013Chinese Journal of Aeronautics2013,26,4:34
7The characteristics of atmospheric CO_2 concentration variation of four national background stations in China显示文摘Atmospheric carbon dioxide is an important kind of greenhouse gas which influences global temperature. Its concentration variation could indicate the distribution of human and natural activities in various regions. Through the non-dispersive infrared method, flask sampling of atmospheric CO2 concen- tration was measured weekly at four national background stations including Waliguan, Shangdianzi, Lin’an, and Longfengshan. Based on the data collected from September 2006 to August 2007, along with the Waliguan station’s experience on in situ observational data processing, the selection methods for sampling data through the atmospheric background CO2 concentration analysis were preliminarily discussed. On the basis of this result, the variation features of the four typical regions’ atmospheric background CO2 concentration was analyzed for the first time. The results show that the atmospheric CO2 concentration at Waliguan, Shangdianzi, Lin’an, and Longfengshan is 383.5, 385.9, 387.8, and 384.3 ppm, respectively. During the research period, CO2 concentration at the Waliguan station changed slightly. However, the CO2 concentration changed sharply at the Shangdianzi and the Lin’an stations due to the great influence of human activities in the Jingjinji and the Changjiang Delta economic zones, and changed regularly with seasons at Longfengshan station under dual influences of human activities and plant photosynthesis. The results from this study can lay the foundation for more profound studies on atmospheric CO2 concentration level of different areas in China, and could be used to improve the understanding of carbon source and sink distribution.LIU LiXin, ZHOU LingXi, ZHANG XiaoChun, WEN Min, ZHANG Fang, YAO Bo & FANG ShuangXi Key Laboratory for Atmospheric Chemistry, Centre for Atmosphere Watch and Services (CAWAS), Chinese Academy of Meteoro- logical Sciences (CAMS), China Meteorological Administration (CMA), Beijing 100081, China 2009Science China Earth Sciences2009,52,11:26
8Measure theory of statistical convergence显示文摘The question of establishing measure theory for statistical convergence has been moving closer to center stage, since a kind of reasonable theory is not only fundamental for unifying various kinds of statistical convergence, but also a bridge linking the studies of statistical convergence across measure theory, integration theory, probability and statistics. For this reason, this paper, in terms of subdifferential, first shows a representation theorem for all finitely additive probability measures defined on the σ-algebra A of all subsets of N, and proves that every such measure can be uniquely decomposed into a convex combination of a countably additive probability measure and a statistical measure (i.e. a finitely additive probability measure μ with μ(k) = 0 for all singletons {k}). This paper also shows that classical statistical measures have many nice properties, such as: The set S of all such measures endowed with the topology of point-wise convergence on A forms a compact convex Hausdorff space; every classical statistical measure is of continuity type (hence, atomless), and every specific class of statistical measures fits a complementation minimax rule for every subset in N. Finally, this paper shows that every kind of statistical convergence can be unified in convergence of statistical measures.CHENG LiXin LIN GuoChen LAN YongYi LIU Hui 2008Science China Mathematics2008,51,12:26
9Central Limit Theorems for Asymptotically Negatively Associated Random FieldsLixin Zhang Department of Mathematics, Zhejiang University. Xixi Campus. Hangzhou 310028. P. R. China 2000Acta Mathematica Sinica,English Series2000,16,4:25
10Characterization of personal exposure concentration of fine particles for adults and children exposed to high ambient concentrations in Beijing, China显示文摘In China, the health risk from overexposure to particles is becoming an important public health concern. To investigate daily exposure characteristics to PM 2.5 with high ambient concentration in urban area, a personal exposure study was conducted for school children, and office workers in Beijing, China. For all participants (N = 114), the mean personal 24-hr exposure concentration was 102.5, 14.7, 0.093, 0.528, 0.934, 0.174 and 0.703 μg/m 3 for PM 2.5 , black carbon, Mn, Al, Ca, Pb, and Fe. Children's exposure concentrations of PM 2.5 were 4-5 times higher than those in related studies. The ambient concentration of PM 2.5 (128.5 μg/m 3 ) was significantly higher than the personal exposure concentration (P < 0.05), and exceed the reference concentration (25 μg/m 3 ) of WHO air quality guideline. Good correlation relationships and significant differences were identified between ambient concentration and personal exposure concentration. The relationships indicate that the ambient concentration is the main factor influencing personal exposure concentration, but is not a good indicator of personal exposure concentration. Outdoor activities (commute mode, exposure to heating, workday or weekend travel) influenced personal exposure concentrations significantly, but the magnitude of the influence from indoor activities (exposure to cooking) was masked by the high ambient concentrations.Xuan Du Qian Kong Weihua Ge Shaojun Zhang Lixin Fu 2010Journal of Environmental Sciences2010,22,11:24
11圆柱形锂离子动力电池放电过程电化学与传热特性研究显示文摘XU Meng ZHANG Zhuqian JIA Li YANG Lixin 2013中国电机工程学报2013,33,32:23
12Improvement of snow depth retrieval for FY3B-MWRI in China显示文摘The primary objective of this work is to develop an operational snow depth retrieval algorithm for the FengYun3B Microwave Radiation Imager(FY3B-MWRI)in China.Based on 7-year(2002–2009)observations of brightness temperature by the Advanced Microwave Scanning Radiometer-EOS(AMSR-E)and snow depth from Chinese meteorological stations,we develop a semi-empirical snow depth retrieval algorithm.When its land cover fraction is larger than 85%,we regard a pixel as pure at the satellite passive microwave remote-sensing scale.A 1-km resolution land use/land cover(LULC)map from the Data Center for Resources and Environmental Sciences,Chinese Academy of Sciences,is used to determine fractions of four main land cover types(grass,farmland,bare soil,and forest).Land cover sensitivity snow depth retrieval algorithms are initially developed using AMSR-E brightness temperature data.Each grid-cell snow depth was estimated as the sum of snow depths from each land cover algorithm weighted by percentages of land cover types within each grid cell.Through evaluation of this algorithm using station measurements from 2006,the root mean square error(RMSE)of snow depth retrieval is about 5.6 cm.In forest regions,snow depth is underestimated relative to ground observation,because stem volume and canopy closure are ignored in current algorithms.In addition,comparison between snow cover derived from AMSR-E and FY3B-MWRI with Moderate-resolution Imaging Spectroradiometer(MODIS)snow cover products(MYD10C1)in January 2010 showed that algorithm accuracy in snow cover monitoring can reach 84%.Finally,we compared snow water equivalence(SWE)derived using FY3B-MWRI with AMSR-E SWE products in the Northern Hemisphere.The results show that AMSR-E overestimated SWE in China,which agrees with other validations.JIANG LingMei WANG Pei ZHANG LiXin YANG Hu YANG JunTao 2014Science China Earth Sciences2014,57,6:22
13Polymer-based EMI shielding composites with 3D conductive networks:A mini-review显示文摘High-frequency electromagnetic waves and electronic products can bring great convenience to people’s life,but lead to a series of electromagnetic interference(EMI)problems,such as great potential dangers to the normal operation of elec-tronic components and human safety.Therefore,the research of EMI shield-ing materials has attracted extensive attention by the scholars.Among them,polymer-based EMI shielding materials with light weight,high specific strength,and stable properties have become the current mainstream.The construction of 3D conductive networks has proved to be an effective method for the prepara-tion of polymer-based EMI shielding materials with excellent shielding effective-ness(SE).In this paper,the shielding mechanism of polymer-based EMI shield-ing materials with 3D conductive networks is briefly introduced,with emphasis on the preparation methods and latest research progress of polymer-based EMI shielding materials with different 3D conductive networks.The key scientific and technical problems to be solved in the field of polymer-based EMI shielding materials are also put forward.Finally,the development trend and application prospects of polymer-based EMI shielding materials are prospected.Lei Wang Zhonglei Ma Yali Zhang Lixin Chen Dapeng Cao Junwei Gu 2021SusMat2021,1,3:22
14The ChinaMAP analytics of deep whole genome sequences in 10,588 individuals显示文摘Metabolic diseases are the most common and rapidly growing health issues worldwide.The massive population-based human genetics is crucial for the precise prevention and intervention of metabolic disorders.The China Metabolic Analytics Project(ChinaMAP)is based on cohort studies across diverse regions and ethnic groups with metabolic phenotypic data in China.Here,we describe the centralized analysis of the deep whole genome sequencing data and the genetic bases of metabolic traits in 10,588 individuals from the ChinaMAP.The frequency spectrum of variants,population structure,pathogenic variants and novel genomic characteristics were analyzed.The individual genetic evaluations of Mendelian diseases,nutrition and drug metabolism,and traits of blood glucose and BMI were integrated.Our study establishes a large-scale and deep resource for the genetics of East Asians and provides opportunities for novel genetic discoveries of metabolic characteristics and disorders.Yanan Cao Lin Li Min Xu Zhimin Feng Xiaohui Sun Jieli Lu Yu Xu Peina Du Tiange Wang Ruying Hu Zhen Ye Lixin Shi Xulei Tang Li Yan Zhengnan Gao Gang Chen Yinfei Zhang Lulu Chen Guang Ning Yufang Bi Weiqing Wang The ChinaMAP Consortium 2020Cell Research2020,30,9:20
15Clinical efficacy of 0.1% pranoprofen in treatment of dry eye patients:a multicenter, randomized, controlled clinical trial显示文摘Chen Jingyao Dong Fei Chen Wei Sun Xuguang Deng Yingping Hong Jing Zhang Mingchang Yang Wenzhao Liu Zuguo Xie Lixin 2014Chinese Medical Journal2014,,13:18
16On-the-fly active learning of interpretable Bayesian force fields for atomistic rare events显示文摘Machine learned force fields typically require manual construction of training sets consisting of thousands of first principles calculations,which can result in low training efficiency and unpredictable errors when applied to structures not represented in the training set of the model.This severely limits the practical application of these models in systems with dynamics governed by important rare events,such as chemical reactions and diffusion.We present an adaptive Bayesian inference method for automating the training of interpretable,low-dimensional,and multi-element interatomic force fields using structures drawn on the fly from molecular dynamics simulations.Within an active learning framework,the internal uncertainty of a Gaussian process regression model is used to decide whether to accept the model prediction or to perform a first principles calculation to augment the training set of the model.The method is applied to a range of single-and multi-element systems and shown to achieve a favorable balance of accuracy and computational efficiency,while requiring a minimal amount of ab initio training data.We provide a fully opensource implementation of our method,as well as a procedure to map trained models to computationally efficient tabulated force fields.Jonathan Vandermause Steven B.Torrisi Simon Batzner Yu Xie Lixin Sun Alexie M.Kolpak Boris Kozinsky 2020npj Computational Materials2020,,1:17
17Hypoglycemic effect of catalpol on high-fat diet/streptozotocin-induced diabetic mice by increasing skeletal muscle mitochondrial biogenesis显示文摘Catalpol, iridoid glycoside,在根值 Rehmanniae 的根存在。一些研究证明了 catalpol 为这效果在导致 streptozotocin 的糖尿病的模型,而是内在的机制有显著血糖过低的效果充分没被阐明。因为 mitochondrial 机能障碍在糖尿病的病理起一个重要作用并且因为改善 mitochondrial 功能可以为糖尿病的处理提供一条新途径,这研究被设计。Catalpol 口头上地予导致的高脂肪的 diet/streptozotocin (HFD/STZ ) 和 metformin 被以为 4 个星期的糖尿病的老鼠日报。身体重量(BW )(IPGTT ) , fasting 血葡萄糖(FBG ) 水平,和葡萄糖处理被测量在期间或在处理以后。结果整个 catalpol 管理的四个连续星期在 BW 没有明显的变化显示出 FBG 水平的剂量依赖者减小。Catalpol 治疗实质地在糖尿病的老鼠减少了浆液总数胆固醇和 triglyceride 层次。另外, catalpol 高效地增加了 mitochondrial ATP 生产并且在骨胳的肌肉织物颠倒了 mitochondrial 膜潜力和 mtDNA 拷贝数字的减少。而且, catalpol (200 mg/kg ) 在骨胳的肌肉救了 mitochondrial 超微结构,与传播电子显微镜学检测了。peroxisome 的相对 mRNA 水平(PGC1 ) 当这效果被 catalpol 颠倒时,激活 proliferator 的受体 gamma 激活剂 1 显著地在糖尿病的老鼠的肌肉组织被减少,导致一条剂量依赖者起来规定。一起拿,我们发现 catalpol 能够经由在 HFD/STZ-induced 糖尿病的老鼠的骨胳的肌肉改进 mitochondrial 功能的阴沉的 FBG 水平。Xia Li Zhimeng Xu Zhenzhou Jiang Lixin Sun Jinzi Ji Jingshan Miao Xueji Zhang Xiaojie Li Shan Huang Tao Wang Luyong Zhang 2014Acta Biochimica et Biophysica Sinica2014,46,9:16
18High-resolution remote sensing image-based extensive deformation-induced landslide displacement field monitoring method显示文摘Shanjun Liu Han Wang Jianwei Huang Lixin Wu 2015International Journal of Coal Science & Technology2015,2,3:16
19Response-surface-based structural reliability analysis with random and interval mixed uncertainties显示文摘Traditional reliability analysis requires probability distributions of all the uncertain parameters.However,in many practical applications,the variation bounds can be only determined for the parameters with limited information.A complex hybrid reliability problem then will be caused when the random and interval variables coexist in a same structure.In this paper,by introducing the response surface technique,we develop a new hybrid reliability method to efficiently compute the interval of the failure probability of the structure due to the probability-interval hybrid uncertainty.The present method consists of a sequence of iterations.At each step,a response surface model is constructed for the limit-state function by using a quadratic polynomial and a modified axial experimental design method.An approximate hybrid reliability problem is created based on the response surface model,which is subsequently solved by an efficient decoupling approach.An updating strategy is suggested to improve the quality of the response surface and whereby ensure the reliability analysis precision.A computational procedure is then summarized for the whole iterations.Four numerical examples and also a practical application are provided to demonstrate the effectiveness of the present method.HAN Xu JIANG Chao LIU LiXin LIU Jie LONG XiangYun 2014Science China(Technological Sciences)2014,57,7:14
20Study on the antiulcer effects of Veronicastrum axillare on gastric ulcer in rats induced by ethanol based on tumor necrosis factor-α(TNF-α)and endothelin-1(ET-1)显示文摘Objective:To assess whether Veronicastrum axillare(V.axillare)can ameliorate ethanol-induced gastric mucosal lesions in rats,reduce the production of pro-inflammatory cytokines,suppress apoptosis and improve local microcirculation disturbances.Methods:Totally 48 male Sprague-Dawley rats were randomly divided into six groups,eight rats in each group.Rats in the normal group and the model group were administered with 0.9%normal saline respectively.Rats in the positive group and ranitidine group were administered with 0.18%ranitidine suspension by intragastric administration respectively.Those in the high dose V.axillare group,the medium dose V.axillare group and the low dose V.axillare group were administrated with V.axillare at the daily dose of 2.8 g/kg,1.4 g/kg and 0.7 g/kg by intragastric administration.Gastric mucosal lesions were produced by intragastric administration of absolute ethanol.Water extract of V.axillare was successively injected for 14 d and last day was injected 1 h before ethanol administration.Gastric mucosal ulcer index and ulcer inhibitory rate were counted by improved Guth methods.The tissue sections were made for pathological histology analysis.Also,we measured the concentrations of tumor necrosis factor-α(TNF-α)and endothelin-1(ET-1)in gastric mucosal,as an index of the pro-inflammatory cytokines,apoptosis and local microcirculation.Besides,the mRNA contents of TNF-αand ET-1 were measured to verify effects on gene expression by real-time fluorescent quantitative PCR.Results:Water extract of V.axillare significantly ameliorated the gastric mucosal lesions induced by ethanol administration(P<0.01).Pro-inflammatory cytokines,TNF-a and ET-1 were increased after ethanol administration and significantly reduced by water extract of V.axillare.The expressions of TNF-αand ET-1 mRNA were also be inhibited by water extract of V.axillare.Conclusion:Current evidences show water extract of V.axillare is effective for defending against ethanol-induced gastric mucosal lesions,significantly inhibiting the production of proinflammatory cytokines and the expressions of TNF-αand ET-1 mRNA,which may be useful for inhibiting apoptosis and improving local microcirculation.Yong Du Weichun Zhao Leilei Lu Jiayan Zheng Xishi Hu Zhehan Yu Lixin Zhu 2013Asian Pacific Journal of Tropical Biomedicine2013,3,12:13
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