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Biomass estimation and uncertainty analysis based on CBERS-02 CCD camera data and field measurement

Science china(Technological Sciences) 2005年第S2期48卷 116-128页

作者： CHEN Liangfu1,2, GAO Yanhua1,3, CHENG Yu1,3, WEI Zheng1,3, XIAO Qing1,4. LIU Qinhuo1, YU Tao1, LIU Qijing5, GU Xingfa1 & TIAN Guoliang1 1. State Key Laboratory of Remote Sensing Science, institute of Remote Sensing Applications, Chinese Academy of Sciences, beijing 100101, china 2. Geography and Environment College, Jiangxi Normal University, Nanchang 330027, china 3. Graduate University of Chinese Academy of Sciences, beijing 100039, china 4. beijing research institute of uranium geology, beijing 100875, china 5. institute of Geographic Sciences and Natural Resources research, Chinese Academy of Sciences, beijing 100101, china State Key Laboratory of Remote Sensing Science Institute of Remote Sensing Applications Chinese Academy of Sciences Beijing 100101 China

The study site is located in Qianyanzhou experimental station and the surrounding area. Based on CBERS-02 satellite data and field measurement, we not only discussed the relationship between NDVI and biomass of two species of coniferous plantations, namely, Pinus massoniana Lamb and Pinus elliottii Engelm, but also introduced the biomass models based on NDVI. The comparison between measured biomass in Qianyanzhou and biomass derived from CBERS-02 CCD data showed that it is feasible to estimate biomass based on NDVI. But its limitations cannot be ignored. This kind of model depends on the dominant vegetation species. There are some effect factors in estimating biomass based on NDVI. This paper analyzes these factors based on fine-resolution CBERS-02 CCD data and some conclusions are drawn: In Qianyanzhou, the area with good vegetation coverage, the nonlinearity of NDVI has little influence on scaling-up of NDVI. As a result of surface heterogeneity, scaling-up can cause NDVI within each pixel to change. Because scaling-up can cause pixel attribute to change, the applicability of biomass model is one of the sources of error in estimating biomass.

关键词： NDVI biomass scaling effect scaling-up.

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Recommendation Method for Contrastive Enhancement of Neighborhood Information

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Computers, Materials & Continua 2024年第1期78卷 453-472页

作者： Hairong Wang beijing Zhou Lisi Zhang He Ma School of Computer Science and Engineering North Minzu UniversityNingxia750021China

Knowledge graph can assist in improving recommendation performance and is widely applied in various person-alized recommendation ***,existing knowledge-aware recommendation methods face challenges such as weak user-item interaction supervisory signals and noise in the knowledge *** tackle these issues,this paper proposes a neighbor information contrast-enhanced recommendation method by adding subtle noise to construct contrast views and employing contrastive learning to strengthen supervisory signals and reduce knowledge ***,first,this paper adopts heterogeneous propagation and knowledge-aware attention networks to obtain multi-order neighbor embedding of users and items,mining the high-order neighbor informa-tion of users and ***,in the neighbor information,this paper introduces weak noise following a uniform distribution to construct neighbor contrast views,effectively reducing the time overhead of view *** paper then performs contrastive learning between neighbor views to promote the uniformity of view information,adjusting the neighbor structure,and achieving the goal of reducing the knowledge noise in the knowledge ***,this paper introduces multi-task learning to mitigate the problem of weak supervisory *** validate the effectiveness of our method,experiments are conducted on theMovieLens-1M,MovieLens-20M,Book-Crossing,and Last-FM *** results showthat compared to the best baselines,our method shows significant improvements in AUC and F1.

关键词： Contrastive learning knowledge graph recommendation method

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2023 Guideline for the management of hypertension in the elderly population in china

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Journal of Geriatric Cardiology 2024年第6期21卷 589-630页

作者： Hypertension Branch of Chinese Geriatrics Society,beijing Hypertension Association,National Clinical research Center of the Geriatric Diseases Qi HUA Li FAN Zeng-Wu WANG Jing LI 不详 Xuanwu Hospital Capital Medical UniversityBeijingChina Chinese PLA General Hospital BeijingChina Fuwai Hospital Chinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina

Preamble Hypertension is one of the most common chronic diseases and the primary risk factor for stroke,myocardial infarction and even cardiovascular *** than half of the elderly population has high blood *** people are a unique group,and strategies for the prevention,diagnosis,evaluation,and treatment of hypertension in elderly individuals differ significantly from those in the general population.

关键词： hypertension prevention diagnosis

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Top 10 Influential Events in carbon neutrality and climate change response for 2023

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Frontiers in Energy 2024年第1期18卷 1-3页

作者： research institute of Carbon Neutrality of Shanghai Jiao Tong University research institute of Carbon Neutrality Shanghai Jiao Tong UniversityShanghai 200240China

In 2023, the global community intensified its efforts towards achieving carbon neutrality and addressing climate change, witnessing several impactful events. research institute of Carbon Neutrality, Shanghai Jiao Tong University compiled the Top 10 Events (in chronological order) in the field of global carbon neutrality and climate change response for 2023, to share with readers these significant moments that document the ongoing ambition and collective efforts of human society.

关键词： neutral collective intensified

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Progress and review of the studies on the end-Triassic mass extinction event

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Science china Earth Sciences 2005年第12期48卷 2049-2060页

作者： DENG Shenghui1,2, LU Yuanzheng1,2,3 & XU Daoyi4.1. research institute of Petroleum Exploration and Development, beijing 100083, china 2. Key Laboratory of Oil and Gas Reservoir of Petro{4., beijing 100083, china 3. china University of Geosciences, beijing 100083, china 4. institute of geology, china Earthquake Administration, beijing 100029, china research institute of Petroleum Exploration and Development Beijing China Key Laboratory of Oil and Gas Reservoir of Petrochina Beijing China china University of Geosciences Beijing China institute of geology China Earthquake Administration Beijing China

The mass extinction at the end-Triassic is one of the five biggest in the Phanerozoic. However,it is the least well understood among these five events, and only till last decade it became a great academic interesting subject to geologists. The evidences for this event come obviously from bivalves, brachiopods, ammonites, corals, radiolaria, ostracods and foraminifera of marine habitats, and plants and tetrapods of terrestrial realm. By contrast, for some of other groups, such as marine gastropods and marine vertebrates, no mass extinction has been recog-nized yet. The extinction event is strongly marked at specific level but shown a complicated situa-tion at generic and family levels. Dramatic changing of the environment, such as the temperature raise due to the greenhouse effect, the marine anoxic habitats caused by a sudden transgression after the regression at the end of Triassic, has been claimed to be the main cause of the extinction. Many hypotheses have been suggested to demonstrate the mechanisms of the environment changing, among which two popular ones are the bolide impact and volcanic eruption. The Triassic-Jurassic (Tr-J) boundary mass extinction event is still poorly understood because no enough data have been obtained from the Tr-J boundary successional sections of both marine and terrestrial sediments, and most of these studies were regionally restricted. The basic aspects of the event and its associated environmental conditions remain poorly characterized and the causal mechanism or mechanisms are equivocal. Some authors even doubt its occurrence. china has many successionally developed terrestrial and marine Tr-J sections. Detailed studies of these sections may be important and significant for well understanding of the event.

关键词： progress, review, end-Triassic, mass extinction, mechanism, Tr-J boundary.

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Environmental　risk　assessment　of　the　middle　route　of　south－to－north　water　transferring　source　project　in　china

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Journal of Environmental Sciences 1996年第3期8卷 285-291页

作者： Wang Huadong Wang Fei(institute of Environmental Sciences,beijing Normal University, beijing 100875, china) institute of Environmental Sciences Beijing Normal University Beijing 100875 China

This paper focused on the environment risk of the middle route of south-to-north water transferring source project in china. Analytic hierarchy process was applied to risk identification,fuzzy probability-fault tree analysis to risk probability assessment,statistics and analogy process to risk consequences assessment, lastly, grey relevant analysis and comprehensive index process to risk impact evaluation. The main environment risk accident of the project is dam failure, the main causative factors of the accident are catastrophic flood and wrecking earthquake. The flash flood, due to dam failure, will impact on nature, society and economy. The major environment risk areas are Jingzhou and Xiangfan,Hubei Province. The environment risk management measures should be adopted in order to ensure the safety of the project-environment complex system.

关键词： water source project environment risk risk assessment

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Development and application of ergodicity model with FRCM and FLAR for hydrological process

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Science china(Technological Sciences) 2009年第2期52卷 379-386页

作者： WANG HongRui1, FENG QiLei2, LIN Xin3 & ZENG WenYi4.1 College of Water Science, Key Laboratory for Water and Sediment Sciences of the Ministry of Education, beijing Normal University, beijing 100875, china 2 School of Science, beijing {4. of Education, beijing 100011, china 3 School of Mathematical Sciences, beijing Normal University, beijing 100875, china 4.College of Information Science and Technology, beijing Normal University, beijing 100875, china School of Science Beijing Institute of Education School of Mathematical Sciences Beijing Normal University College of Information Science and Technology Beijing Normal University

In this paper, a new ergodic property analysis model of hydrological process is proposed based on fuzzy-rough c-means clustering (FRCM), autocorrelogram, and fuzzy least absolute regression (FLAR). A precipitation time series (1951―2004. from Shanghai Hydrology Station is then analyzed with the model. The results show that the precipitation time series of April, May, June, and September has er-godic property. We conclude that in the long run, the precipitation of April, May, June, and September will not keep decreasing; it will converge to its mean value in some period.

关键词： hydrological process ergodic autocorrelogram fuzzy-rough c-means clustering fuzzy least absolute regression

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Functional central limit theorem for super α-stable processes

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Science china Mathematics 2004年第6期47卷 874-881页

作者： HONG WenmingDepartment of Mathematics, beijing Normal University, beijing 100875, china Department of Mathematics Beijing Normal University Beijing China

A functional central limit theorem is proved for the centered occupation time process of the super α-stable processes in the finite dimensional distribution sense. For the intermediate dimensions α < d < 2α (0 < α ≤ 2), the limiting process is a Gaussian process, whose covariance is specified; for the critical dimension d= 2α and higher dimensions d < 2α, the limiting process is Brownian motion.

关键词： super α-stable processes occupation time central limit theorem evolution equation

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On the stability of diffusion processes with state-dependent switching

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Science china Mathematics 2006年第9期49卷 1258-1274页

作者： XI Fubao & ZHAO Liqin Department of Mathematics, beijing institute of Technology, beijing 100081, china School of Mathematical Sciences, beijing Normal University, beijing 100875, china Department of Mathematics Beijing Institute of Technology Beijing China School of Mathematical Sciences Beijing Normal University Beijing China

In this paper we consider the stability for diffusion processes with state-dependent switching. We first prove their Feller continuity by the coupling methods. Furthermore, we also prove their strong Feller continuity and their exponential ergodicity under some reasonable conditions. Finally, we append a very brief discussion about the regularity of these processes.

关键词： Feller continuity, coupling, strong Feller continuity, exponential ergodicity,state-dependent switching.

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Refraction of light in media

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Science china(Physics,Mechanics & Astronomy) 2007年第5期50卷 591-600页

作者： ZHANG Tao Key Laboratory of Beam Technology and Material Modification of Ministry of Education, institute of Low Energy Nuclear Physics, beijing Normal University, beijing 100875, china beijing Radiation Center, beijing 100875, china Key Laboratory of Beam Technology and Material Modification of Ministry of Education Institute of Low Energy Nuclear Physics Beijing Normal University Beijing 100875 China

The roles of the magnetic field and electric field of the light are investigated when the light is refracted in the medium. The model of the electron cloud conductor is presented. Electron cloud in a molecule is treated as a conductor and the Faraday’s Law is applied to this conductor that is in the alternating magnetic field of the light. dBM/dt of the light gives rise to an alternating induced current on the electron cloud conductor, and the light exchanges energy, i.e. the refractive energy, with the elec- tron cloud conductor. Formulas of refractive index, which is the ratio of light speed in vacuum to that in the medium, are derived with this model. These formulas are tested with several mediums and Langevin’s diamagnetic susceptibility of helium gas, and the results are in good agreement with the measured data. The anisotropy and the nonlinearity of the refractive index are explained with the theory described in this work.

关键词： refractive index, light, speed, medium, propagation

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