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Adsorption of graphene oxide/chitosan porous materials for metal ions

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Chinese Chemical Letters 2011年第7期22卷 859-862页

作者： Yong Qiang He na na Zhang Xiao Dong Wang Department of Applied Chemistry Yuncheng University Yuncheng 044000 China School of Science Tianjin University Iianjin 300072 China

Porous graphene oxide/chitosan （PGOC） materials were prepared by a unidirectional freeze-drying method. Their porous structure, mechanical property and adsorption for metal ions were investigated. The results show that the incorporation of graphene oxide （GO） significantly increased the compressive strength of the PGOC materials. The saturated adsorption capacity of Pb^2＋ increased about 31%, up to 99 mg/g when 5 wt% GO was incorporated These biodegradable, nontoxic, efficient PGOC materials will be a potential adsorbent for metal ions in aqueous solution.

关键词： Chitosan Graphene oxide Porous material Adsorption Metal ions

Maximum principle for anticipated recursive stochastic optimal control problem with delay and Lvy processes

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Applied Mathematics(A Journal of Chinese Universities) 2014年第1期29卷 67-85页

作者： LI na WU Zhen School of Mathematics Shandong University Mathematics Department QiLu Normal Institute

In this paper, we study the stochastic maximum principle for optimal control prob- lem of anticipated forward-backward system with delay and Lovy processes as the random dis- turbance. This control system can be described by the anticipated forward-backward stochastic differential equations with delay and L^vy processes （AFBSDEDLs）, we first obtain the existence and uniqueness theorem of adapted solutions for AFBSDEDLs; combining the AFBSDEDLs＇ preliminary result with certain classical convex variational techniques, the corresponding maxi- mum principle is proved.

关键词： maximum principle stochastic optimal control L′evy processes stochastic differential equation with delay anticipated backward differential equation

On Weakly s-Semipermutable Subgroups of Finite Groups

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Algebra Colloquium 2014年第4期21卷 541-550页

作者： na Tang Xianhua Li School of Mathematics Science Soochow University Suzhou Jiangsu 215006 China

We prove that a finite group G is p-supersolvable or p-nilpotent if some sub- groups of G are weakly s-semipermutable in G. Several earlier results are generalized.

关键词： weakly s-semipermutable subgroup p-nilpotent group p-supersolvable group

Positive Solutions for a Class of Fractional p-Laplacian Equation with Critical Sobolev Exponent and Decaying Potentials

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Acta Mathematicae Applicatae Sinica 2022年第2期38卷 463-483页

作者： na LI Xiao-ming HE College of Science Minzu University of ChinaBeijing 100081China

In this paper,we study the existence of positive solution for the p-Laplacian equations with frac-tional critical nonlinearity{-Δ)_(p)^(s)u+V(x)|u|^(p-2)u=K(x)f(u)+P(x)|u|p_(s)^(*)-^(2)u,x∈R^(N),u∈Ds,p(RN),where s∈(0,1),p_(s)^(*)=Np/N-sp,N>sp,p>1 and V(x),K(x)are positive continuous functions which vanish at infinity,f is a function with a subcritical growth,and P(x)is bounded,nonnegative continuous *** using variational method in the weighted spaces,we prove the above problem has at least one positive solution.

关键词： Fractional p-Laplacian Variational methods Mountain Pass Theorem Critical growth Vanishing potential

Determination and ecological risk assessment of arsenic and mercury in sediments from the Changjiang River Estuary and adjacent East China Sea

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Acta Oceanologica Sinica 2021年第4期40卷 32-38页

作者： Yu'na Zhang Qianwen Wang Central Laboratory Qingdao Agricultural UniversityQingdao 266109China

Arsenic(As)and mercury(Hg)are pollutants presented in marine environment.A process of atomic fluorescence spectrometry was proposed for the simultaneous determination of As and Hg in marine sediment samples(n=38)collected from the Changjiang River Estuary and adjacent East China *** proposed method used an optimized pretreatment procedure in an aqua regia–H_(2)O digestion *** of As and Hg increased to97%and 98%,respectively,with suitable precisions(2.7%–4.1%)under optimized process *** and Hg were widely presented in these samples,with the ranges of content values were 2.39–8.77μg/g for As and48.03–410.8 ng/g for *** indicate that anthropogenic factors strongly influence the abundances of As and Hg in investigated *** preliminary environmental risk assessment was investigated using the Igeoaccumulation index(Igeo)and anthropogenic contribution rate(M).Findings reveal that Hg demonstrates a strong ecological risk(with average values of 1.3 and 72%for Igeo and M,respectively)in the sediments from the Changjiang River Estuary and adjacent East China ***,Hg should be considered in future investigations.

关键词： arsenic mercury marine sediment spatial distributions ecological risk

Protection zone in a diffusive predator-prey model with Ivlev-type functional response

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Applied Mathematics(A Journal of Chinese Universities) 2020年第4期35卷 437-451页

作者： ZHANG Li-na XU Fei Department of Mathematics and statistics Northwest Normal UniversityLanzhou 730070China

The effect of a protection zone on a diffusion predator-prey model with Ivlev-type functional response is *** discuss the existence and non-existence of positive steady state solutions by using the bifurcation *** is shown that the protection zone for prey has beneficial effects on the coexistence of the two species when the growth rate of predator is ***,we examine the dependence of the coexistence region on the efficiency of the predator capture of the prey and the protection zone.

关键词： Ivlev-type functional response protection zone bifurcation

Dynamics of Matter-Wave Solitons for Three-Dimensional Bose-Einstein Condensates with Time-Space Modulation

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Chinese Physics Letters 2012年第9期29卷 12-16页

作者： XIONG na LI Biao Nonlinear Science Center Ningbo UniversityNingbo 315211

By two direct assumption methods and symbolic computation,we present two families of one-soliton solutions and a family of two-soliton solutions with some arbitrary functions for the three-dimensional Gross–Pitaevskii equation with time-space *** we investigate the dynamics of these matter-wave solitons in three-dimensional Bose–Einstein *** can see that the intensities of both one-solitons and two-solitons first increase rapidly to the condensation peak value,then decay very slowly to the background *** these matter-wave solitons in three-dimensional Bose–Einstein condensates can remain for a sufficiently long time to be fully observed and modulated for real applications in today's experiments.

关键词： value. Einstein solitons

Interaction between the gut microbiome and mucosal immune system

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Military Medical Research 2017年第3期4卷 170-177页

作者： na Shi na Li Xinwang Duan Haitao Niu Institute of Laboratory Animal Sciences Chinese Academy of Medical Sciences (CAMS) and Comparative Medicine Center Peking Union Medical Collage (PUMC) Key Laboratory of Human Disease Comparative Medicine Ministry of Health Department of Rheumatology the Second Affiliated Hospital of Nanchang University

The gut microbiota, the largest symbiotic ecosystem with the host, has been shown to play important roles in maintaining intestinal homeostasis. Dysbiosis of the gut microbiome is caused by the imbalance between the commensal and pathogenic microbiomes. The commensal microbiome regulates the maturation of the mucosal immune system, while the pathogenic microbiome causes immunity dysfunction, resulting in disease *** gut mucosal immune system, which consists of lymph nodes, lamina propria and epithelial cells, constitutes a protective barrier for the integrity of the intestinal tract. The composition of the gut microbiota is under the surveillance of the normal mucosal immune system. Inflammation, which is caused by abnormal immune responses,influences the balance of the gut microbiome, resulting in intestinal diseases. In this review, we briefly outlined the interaction between the gut microbiota and the immune system and provided a reference for future studies.

关键词： Microbiome Immunity Inflammation

Neural Network-based Adaptive State-feedback Control for High-order Stochastic Nonlinear Systems

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自动化学报 2014年第12期40卷 2968-2972页

作者： MIN Hui-Fang DUAN na School of Electrical Engineering & Automation Jiangsu Normal University

This paper focuses on investigating the issue of adaptive state-feedback control based on neural networks(NNs)for a class of high-order stochastic uncertain systems with unknown nonlinearities. By introducing the radial basis function neural network(RBFNN) approximation method, utilizing the backstepping method and choosing an approximate Lyapunov function, we construct an adaptive state-feedback controller which assures the closed-loop system to be mean square semi-global-uniformly ultimately bounded(M-SGUUB). A simulation example is shown to illustrate the effectiveness of the design scheme.

关键词：径向基函数神经网络状态反馈控制器随机非线性系统自适应高阶 Lyapunov函数非线性问题不确定系统