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Spatiotempora　lcomplexity　of　the　Cubic　Ginzburg－Landau　Equation

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Communications in Nonlinear Science and Numerical Simulation 1996年第4期1卷 14-19页

作者： Boling GUO, Zhujung JING  & Bainian lu  (Center for Nonlinear Studies, Institute of Applied Physicsand Computational mathematics, beijing100088)  (Institute of mathematics, Academia Sinica, beijing100080)  (department of Center for Nonlinear Studies Institute of Applied Physics and Computational Mathematics Beijing 100088 China Institute of mathematics Academia Sinica Beijing 100080 China department of mathematics Shaanxi Normal University Xi'an 710062 Shaanxi China

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关键词： Ginzburg-Landau equation Pesudo-spectral Methods Bifurcation Chaos

The carrying capacity for vegetation of forest land across china:Near real-time monitoring and short-term forecasting based on satellite observation

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Geography and Sustainability 2024年第3期5卷 415-429页

作者： Huiqian Yu Nan lu Bojie Fu lu Zhang Shufen Pan State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China university of Chinese Academy of Sciences Beijing 100049China Faculty of Geographical Science Beijing Normal UniversityBeijing 100875China College of Forestry Wildlife and EnvironmentAuburn UniversityAL 36849USA department of Engineering Boston CollegeChestnut HillMA 02467USA

Ecological restoration projects implemented over the past 20 years have substantially increased forest coverage in china,but the high tree mortality of new afforestation forest remains a challenging but unsolved *** is still not clear how much vegetation can be sustained by the forest lands with given water,energy and soil conditions,i.e.,the carrying capacity for vegetation(CCV)of forest lands,which is the prerequisite for planning and implementing forest restoration ***,we used a simplified method to evaluate the CCV across forest lands ***,based on leaf area index(LAI)dataset,we use boosted regression tree and multiple linear regression model to analyze the CCV during 2001-2020 and 2021-2030 and explore the contribution of environmental *** find that there are three typical regions with lower CCV located in the Loess Plateau and the southern region of the Inner Mongolia Plateau,the Hengduan Mountain region,and the Tianshan *** importantly,the vegetation in the regions near the dry-wet climate transition zone show excess local carrying capacity for vegetation over the past two decades and they are more susceptible to potential climatic *** comparison,in the Greater Khingan Mountains and Hengduan Mountains,there is high potential to improve the forest ***,precipitation and soil affects the CCV by shaping the vegetation in the optimal *** indicates that more consideration should be given to restrictions of regional environmental constraints when planning afforestation and forest *** study has important implications for guiding future forest scheme in china.

关键词： Carrying capacity for vegetation Leaf area index Ecosystem restoration Forest management

Local field potentials,spiking activity,and receptive fields in human visual cortex

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Science china(Life Sciences) 2024年第3期67卷 543-554页

作者： lu luo Xiongfei Wang Junshi lu Guanpeng Chen Guoming luan Wu Li Qian Wang Fang Fang School of Psychological and Cognitive Sciences and beijing Key Laboratory of Behavior and Mental Health Peking UniversityBeijing 100871China School of Psychology Beijing Sport UniversityBeijing 100084China department of Neurosurgery Sanbo Brain HospitalCapital Medical UniversityBeijing 100093China beijing Key Laboratory of Epilepsy Epilepsy CenterSanbo Brain HospitalCapital Medical UniversityBeijing 100093China IDG/McGovern Institute for Brain Research Peking UniversityBeijing 100871China Peking-Tsinghua Center for Life Sciences Peking UniversityBeijing 100871China beijing Institute for Brain Disorders Beijing 100069China State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research Beijing Normal UniversityBeijing 100875China

The concept of receptive field(RF) is central to sensory neuroscience. Neuronal RF properties have been substantially studied in animals,while those in humans remain nearly unexplored. Here, we measured neuronal RFs with intracranial local field potentials(LFPs) and spiking activity in human visual cortex(V1/V2/V3). We recorded LFPs via macro-contacts and discovered that RF sizes estimated from lowfrequency activity(LFA, 0.5–30 Hz) were larger than those estimated from low-gamma activity(LGA, 30–60 Hz) and high-gamma activity(HGA, 60–150 Hz). We then took a rare opportunity to record LFPs and spiking activity via microwires in V1 simultaneously. We found that RF sizes and temporal profiles measured from LGA and HGA closely matched those from spiking activity. In sum, this study reveals that spiking activity of neurons in human visual cortex could be well approximated by LGA and HGA in RF estimation and temporal profile measurement, implying the pivotal functions of LGA and HGA in early visual information processing.

关键词： human visual cortex receptive field intracranial EEG local field potential spiking activity

WEIGHTED WEAK TYPE ESTIMATES INVOLVING SPACES GENERATED BY BLOCKS

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Analysis in Theory and Applications 1994年第1期10卷 58-64页

作者： lu Shanzhen Guido Weiss beijing normal university Washington university inst. Louis 1. department of mathematics Beijing Normal University 100875 Beijing P.R. china 2. department of mathematics Washington University in St. Louis 63130 MO U.S.A.

The problem studied in this paper is how to establish weighted estimates of weak type near L^1 for those operators that are not of weak type(1,1).

关键词： show Math WEIGHTED WEAK TYPE ESTIMATES INVOLVING SPACES GENERATED BY BLOCKS

Wind disturbance compensated path-following control for fixed-wing UAVs in arbitrarily strong winds

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Chinese Journal of Aeronautics 2024年第2期37卷 431-445页

作者： Hao lu Lan GAO Yunda YAN Mingzhe HOU Chenliang WANG Hangzhou Innovation Institute Beihang UniversityHangzhou 310051China School of Information Science and Technology Hangzhou Normal UniversityHangzhou 311121China department of Computer Science University College LondonLondon WC1E 6BTUnited Kingdom Center for Control Theory and Guidance Technology Harbin Institute of TechnologyHarbin 150001China School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China

Wind is the primary challenge for low-speed fixed-wing unmanned aerial vehicles to follow a predefined flight *** cope with various wind conditions,this paper proposes a wind disturbance compensated path following control strategy where the wind disturbance estimate is incorporated with the nominal guiding vector field to provide the desired airspeed direction for the *** the control input vector for the outer-loop kinematic subsystem needs to satisfy a magnitude constraint,a scaling mechanism is introduced to tune the proportions of the compensation and nominal ***,an optimization problem is formulated to pursue a maximum wind compensation in strong winds,which can be solved analytically to yield two scaling factors.A cascaded inner-loop tracking controller is also designed to fulfill the outer-loop wind disturbance compensated guiding vector ***-fidelity simulation results under sensor noises and realistic winds demonstrate that the proposed path following algorithm is less sensitive to sensor noises,achieves promising accuracy in normal winds,and mitigates the deviation from a desired path in wild winds.

关键词： Path following Guiding vector field Wind disturbance Disturbance rejection Fixed wings

Scaling laws governing the elastic properties of 3D graphenes

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Science china(Technological Sciences) 2024年第6期67卷 1748-1756页

作者： LI Ming lu Guo YU HaoDong LI MengLei ZHENG FaWei Centre for Quantum Physics Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement(MOE)School of PhysicsBeijing Institute of TechnologyBeijing100081China beijing Key Lab of Nanophotonics&Ultrafine Optoelectronic Systems School of PhysicsBeijing Institute of TechnologyBeijing100081China Laboratory of Computational Physics Institute of Applied Physics and Computational MathematicsBeijing100088China department of Physics Capital Normal UniversityBeijing100048China

In this study,we comprehensively investigated the scaling law for elastic properties of three-dimensional honeycomb-like graphenes(3D graphenes)using hybrid neural network potential-based molecular dynamics simulations and theoretical *** elastic constants were obtained as functions of honeycomb hole size,denoted by the graphene wall length *** five independent elastic constants in the large-L limit are proportional to L^(-1).The associated coefficients are combinations of elastic constants of two-dimensional ***-order terms including L^(-2)and L^(-3)emerge for finite L *** have three origins,the distorted areas close to the joint lines of 3D graphenes,the variation in solid angles between graphene plates,and the bending distortion of graphene ***,the chirality becomes essential with decreasing L because the joint line structures are different between the armchair and zigzag-type 3D *** findings provide insights into the elastic properties of graphene-based superstructures and can be used for further studies on graphene-based materials.

关键词： scaling law neural network elastic properties 3D graphene

The role of the DLPFC in inductive reasoning of MCI patients and normal agings:An fMRI study

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Science china(Life Sciences) 2009年第8期52卷 789-795页

作者： YANG YanHui1,3,LIANG PeiPeng2,3,lu ShengFu2,3,LI KunCheng1,3 & ZHONG Ning2,3,4 1 Xuanwu Hospital,capital Medical university,beijing 100053,china 2 The International WIC Institute,beijing university of Technology,beijing 100124,china 3 beijing Municipal Lab of Brain Informatics,beijing 100124,china 4 department of Life Science and Informatics,Maebashi Institute of Technology,Maebashi 371-0816,Japan Xuanwu Hospital Capital Medical University Beijing 100053 China The International WIC Institute Beijing University of Technology Beijing 100124 China beijing Municipal Lab of Brain Informatics Beijing 100124 China department of Life Science and Informatics Maebashi Institute of Technology Maebashi 371-0816 Japan

Previous studies of young people have revealed that the left dorsolateral prefrontal cortex(DLPFC) plays an important role in inductive *** fMRI experiment was performed in this study to examine whether the left DLPFC was involved in inductive reasoning of MCI patients and normal agings,and whether the activation pattern of this region was different between MCI patients and normal *** fMRI results indicated that MCI patients had no difference from normal agings in behavior performance(reaction time and accuracy) and the activation pattern of ***,the BOLD response of the DLPFC region for MCI patients was weaker than that for normal agings,and the functional connectivity between the bilateral DLPFC regions for MCI patients was significantly higher than for normal *** together,these results indicated that DLPFC plays an important role in inductive reasoning of agings,and the functional abnormity of DLPFC may be an earlier marker of MCI before structural alterations.

关键词： mild cognitive impairment functional MRI inductive reasoning

A Discrete Singular Integral Operator(In Memory of Professor Long Ruilin)

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Acta Mathematica Sinica,English Series 1998年第2期14卷 235-244页

作者： Fan Dashan (department of Mathematical Sciences,university of Wisconsin-Milwaukee,Milwaukee,WI 53201,USA)(Email:fan@alpha1.csd.uwm.edu)lu Shanzhen (department of mathematics,beijing normal university,beijing 100875,china)(Email:lusz@***)Pan Yibiao (department of mathematics and Statistics,university of Pittsburgh,Pittsburgh,PA 15260,USA)(Email:yibiao@tomato.math.pitt.edu) university of Wisconsin-Milwaukee 美国北京师范大学数学系北京 Pittsburgh大学美国

Suppose that {αk}k∞=-∞ is a Lacunary sequence of positive numbers satisfying infαk+1/αk=α>1 and that Ω（y’）is a function in the Besov space B10,1(Sn-1)where Sn-1 is the unit sphere on Rn（n≥2）.We prove that if ∫Sn-1Ω（y’）dσ（y’）=0 then the discrete singular integral operator TΩf（x）=∫(Sn-1)f（x-αky’）Ω（y’）dσ（y’） and the associated maximal operator TΩf（x）=∫Sn-1f（x-αky’）Ω（y’）dσ（y’） are both bounded in the space L2（Rn）. The theorems in this paper improve a result by Duoandikoetxea and Rubio de Francia in the L2 case.

关键词： Singular integral Besov space Rough kernel

Copper coordination-driven self-assembly and encapsulation of PCR reagents

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Chinese Chemical Letters 2024年第3期35卷 189-192页

作者： Chang lu Jinkai Zheng Juewen Liu Institute of Food Science and Technology Chinese Academy of Agricultural SciencesBeijing 100193China department of Chemistry Waterloo Institute for NanotechnologyUniversity of WaterlooWaterlooONN2L 3G1Canada

Polymerase chain reactions(PCR)are a very important tool for use in cloning,nucleic acid sequencing and diagnostic *** storage conditions of PCR reagents are limited to freezing and a lot of mixing steps are *** this paper,we report using metal ions to form coordination nanomaterials with the intrinsic components of the PCR reagents including dNTP,DNA primers and DNA polymerase as an integrated PCR reaction *** complete PCR reactions,users need only to dissolve the coordination nanomaterials with a buffer and add template DNA.A few transition metal ions were screened and Cu^(2+)was found to be the most effective metal ion for this *** the encapsulation efficiency of PCR reagents was measured,which can reach close to 100%for the primers and DNA polymerase,but only 10%for dNTP because dNTP was *** study also exhibited this integrated PCR reaction system can be used for DNA detection with a similar detection limit to the normal PCR,and showed good stability of encapsulated PCR nanomaterial after storage for a week.

关键词： Metal ions Coordination Encapsulation PCR Storage