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Response of remotely sensed Normalized Difference Water deviation Index to the 2006 Drought of eastern Sichuan Basin

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Science China Earth Sciences 2008年第5期51卷 748-758页

作者： ZHANG WenJiang1, LU QiFeng2, GAO ZhiQiang3 & PENG Jian4 1 School of Water Resource and Hydropower, Sichuan University, Chengdu 610065, China 2 National Satellite Meteorological Center, China Meteorological Administration, Beijing 100081, China 3 Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China 4 School of Environmental Sciences, Peking University, Beijing 100871, China School of Water Resource and Hydropower Sichuan University Chengdu China National Statellite Meteorological Center China Meteorological Administration Beijing China Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China School of Environmental Sciences Peking University Beijing China

One of the most serious droughts in last century occurred in eastern Sichuan Basin in the summer of 2006 (hereinafter called the Drought). The response of Moderate Resolution Imaging Spectroradiometer (MODIS, boarding on NASA satellites of Terra and Aqua) to the Drought was analyzed in order to reach one practicable monitoring solution for regional soil moisture. Temporal process and spatial extension of the Drought were firstly estimated with ground meteorological and hydrological observations. Then, for the whole region of Sichuan and Chongqing, the remotely sensed Normalized Difference Water In- dex (NDWI) for the summers of 2001―2006 were calculated based on 8-day composite MODIS products, which were further used to construct a new water index (Normalized Difference Water deviation Index, NDWDI) to examine the sensitivity of remote sensing in the Drought. The study showed that the NDWDI is more sensitive to regional drought than other absolute-soil-moisture-based indices. With the new index, the study extracted the spatial-temporal characteristics of the 2006 Drought, and explored its developing and withdrawing processes, which agreed with related statistics. Compared with ground method of drought observation, the NDWDI-based remote sensing solution of this paper is more pref- erable and practicable in that the local soil properties of water consumption and supply are implicitly taken into account, and the spatial representativity limit of ground observation is circumvented to a degree as satellite remotely senses the earth surface in a way of two-dimensional pixel matrix. So, the NDWDI-based method can be used to monitor regional soil water stress situation more practically and efficiently.

关键词： Sichuan Basin drought Normalized Difference Water deviation Index response of remote sensing regional scale

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Perceptual Gradient Similarity deviation for Full Reference Image Quality Assessment

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Computers, Materials & Continua 2018年第9期56卷 501-515页

作者： Manyu Jin Tao Wang Zexuan Ji Xiaobo Shen School of Computer Science and Engineering Nanjing University of Science and TechnologyNanjing210094China School of Computer Science and Engineering Nanyang Technology University639798Singapore

Perceptual image quality assessment(IQA)is one of the most indispensable yet challenging problems in image processing and computer vision.It is quite necessary to develop automatic and efficient approaches that can accurately predict perceptual image quality consistently with human subjective evaluation.To further improve the prediction accuracy for the distortion of color images,in this paper,we propose a novel effective and efficient IQA model,called perceptual gradient similarity deviation(PGSD).Based on the gradient magnitude similarity,we proposed a gradient direction selection method to automatically determine the pixel-wise perceptual gradient.The luminance and chrominance channels are both took into account to characterize the quality degradation caused by intensity and color distortions.Finally,a multi-scale strategy is utilized and pooled with different weights to incorporate image details at different resolutions.Experimental results on LIVE,CSIQ and TID2013 databases demonstrate the superior performances of the proposed algorithm.

关键词： Image quality assessment full reference perceptual gradient similarity multi-scale standard deviation pooling

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Strong phonon localization in PbTe with dislocations and large deviation to Matthiessen’s rule

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npj Computational Materials 2019年第1期5卷 277-282页

作者： Yandong Sun Yanguang Zhou Jian Han Wei Liu Cewen Nan Yuanhua Lin Ming Hu Ben Xu Laboratory of Advanced Materials School of Materials Science and EngineeringTsinghua UniversityBeijing 100084People’s Republic of China Mechanical and Aerospace Engineering Department University of California Los AngelesLos AngelesCA 90095USA State Key Laboratory of New Ceramics and Fine Processing School of Materials Science and EngineeringTsinghua UniversityBeijing 100084People’s Republic of China Department of Mechanical Engineering University of South CarolinaColumbiaSC 29208USA

Dislocations can greatly enhance the figure of merit of thermoelectric materials by prominently reducing thermal conductivity.However,the evolution of phonon modes with different energies when they propagate through a single dislocation is unknown.Here we perform non-equilibrium molecular dynamics simulation to study phonon transport in PbTe crystal with dislocations by excluding boundary scattering and strain coupling effect.The frequency-dependent heat flux,phonon mode analysis,and frequency-dependent phonon mean free paths(MFPs)are presented.The thermal conductivity of PbTe with dislocation density on the order of 10^(15)m^(−2) is decreased by 62%.We provide solid evidence of strong localization of phonon modes in dislocation sample.Moreover,by comparing the frequency-dependent phonon MFPs between atomistic modeling and traditional theory,it is found that the conventional theories are inadequate to describe the phonon behavior throughout the full phonon spectrum,and large deviation to the well-known semi-classical Matthiessen’s rule is observed.These results provide insightful guidance for the development of PbTe based thermoelectrics and shed light on new routes for enhancing the performance of existing thermoelectrics by incorporating dislocations.

关键词： phonon dislocation deviation

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Kinetic Theory of ECRM With Axial deviation~*

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Science China Mathematics 1993年第12期36卷 1479-1488页

作者：刘盛纲 University of Electronic Science and Technology of China

Kinetic theory of electron cyclotron resonance maser (ECRM) with axial deviation between electron beam and cavity has been worked out. The dispersion equation of ECRM as well as the formulae of the starting current and the frequency shift of gyromonotron is given in the paper with detailed discussion. Numerical calculations are also given. The results indicate that the eccentricity of electron beam gives serious influences on the parameters of the gyrotron.

关键词： electron cyclotron resonance maser axial deviation dispersion equation.

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Large deviation principles for stationary NA sequences

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Chinese Science Bulletin 1998年第7期43卷 536-540页

作者： HU Yijun Department of Mathematics, Wuhan University, Wuhan 430072, China Department of Mathematics Wuhan University Wuhan China

Under general conditions, the large deviation principles for partial sums of stationary NA sequences are proved.

关键词： NA sequence stationary sequence partial sums large deviation principle.

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A class of strong deviation theorems and an approach of Laplace transformation

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Chinese Science Bulletin 1998年第19期43卷 1605-1610页

作者： LIU Wen Hebei University of Technology, Tianjin 300130, China Hebei University of Technology Tianjin China

The limit properties of the dependent sequence of absolutely continuous random variables are investigated by using the notion of likelihood ratio, and a class of strong limit theorems, represented by inequalities, i.e. the strong deviation theorems, are obtained. In the proof an approach of applying the Laplace transformation to the investigation of the strong limit theorems is proposed.

关键词： strong deviation theorem strong limit theorem likelihood ratio Laplace transformation.

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BOREAL SUMMER CLIMATOLOGY AND STANDARD deviation IN GLOBAL LOW-FREQUENCY STREAMFUNCTION FIELDS AT 200 hPa

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Journal of Tropical Meteorology 2019年第2期25卷 153-161页

作者：季悦李艳杰吴志伟 Key Laboratory of Meteorology Disaster Ministry of Education (KLME)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD) Nanjing University of Information Science and Technology State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Institute of Atmospheric Sciences Fudan University

Based on NCEP/NCAR DOE daily reanalysis dataset during 1980-2015, this study investigates the boreal summer climatology and standard deviation of streamfunction in different low frequency periods(including 10-30 days,30-60 days and more than 60 days) at 200 hPa. Distinctions in the characteristics in different periods are emphasized. It is found that the distribution of streamfunction on the timescale longer than 60 days is mainly zonal symmetric,accompanied by strong variability in the Northern Hemisphere subtropical jet streams. For the 10-30-day timescale, it reflects the zonal fluctuating structure in the middle and high latitudes and large variability in the Southern Hemisphere.Tropical quadrupole structure is observed on the 30-60-day timescale in climatology. Besides, a relative weak standard deviation is also found in this period. This work provides basic knowledge on climatology and variability in low-frequency streamfunction, which has not been fully illustrated in previous studies.

关键词： low-frequency streamfunction boreal summer climatology standard deviation

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央-地协同与偏向视角下产业支持政策创新效应研究

产业经济

引用

产业经济 2024年第3期

作者：周小梅黄鑫

创新是“双循环”新发展格局的重要引擎，如何通过产业支持政策形成市场有效、政府有为的创新体系推动制造业高质量发展至关重要。本文以2012-2019年我国沪深两市A股制造业上市公司数据匹配中央与地方“五年规划”文本，实证分析央-地... 详细信息

创新是“双循环”新发展格局的重要引擎，如何通过产业支持政策形成市场有效、政府有为的创新体系推动制造业高质量发展至关重要。本文以2012-2019年我国沪深两市A股制造业上市公司数据匹配中央与地方“五年规划”文本，实证分析央-地分权制度背景下产业政策的有效边界和作用路径。研究发现：(1)地方产业政策能较好地发挥辖区比较优势并促进企业创新，产权性质和专利属性的异质性分析发现央地政策效果存在明显偏差；(2)央-地政策协同能够实现中央政策前瞻性甄别优势和地方资源效率化整合优势的内嵌互补进而激励企业创新，偏离中央顶层设计或地方禀赋优势的央-地政策偏向不利于企业创新；(3)央-地政策协同既能以财政补贴和税收优惠方式直接推动企业创新，也能通过弱化行政壁垒和地方保护，发挥市场竞争机制间接促进企业创新。本研究丰富了政府产业支持政策对企业创新影响的相关文献，并为释放央-地政策的协同效应提供启示。

关键词：产业支持政策央-地分权偏差协同制造业创新 industrial support policy central-local decentralization deviation synergy manufacturing innovation

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THE UPPER BOUND ESTIMATE OF LARGE deviation FOR INHOMOGENEOUS MARKOV PROCESSES

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Chinese Annals of Mathematics,Series B 1989年第1期10卷 115-131页

作者：芦云刚 Department of Mathematics Beijing Normal University Beijing China

In this paper, the Feynmann-Kac formula is extended to the inhomogeneous case. Using the extended formula, the author studies the upper bound estimate of large deviation for some class of inhomogenous Markov processes... 详细信息

关键词： inhomogeneous deviation generalization 二尹九十九云一 diverse lemma enough 贵一

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The Earth's inner core deviation to plate movement

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Chinese Science Bulletin 2001年第19期46卷 1585-1589页

作者： Dinghua Huang Jinping Wu Yichun Duan Hao Guo Heng Zhang Lingqing Yao Fan Zhang Bin Li Junhui Wang Hongfu Yin The Faculty of Earth Science China University of Geosciences Wuhan China The Ministry of Land and Resources of China Beijing China

Under the premise of the Earth’s layer structure and mass distribution, the solid inner core cannot be stable in the center of the sphere. Thus, the deviation of the inner core is towards the sphere’s center and the liquid outer core must have asymmetrical thermal convection. Based on the two suggestions, a concise and self-consistent global motion model can be built. The model consists of the following cycle: an asymmetrical thermal convection structure in the outer core led by the dislocation of the inner core→the plume is in special upwell position because of differential activation→the formation and split of lithosphere→the split plates drift and assemble in a new location, the mass of which causes the inner core to deviate towards this direction again→the new asymmetry is formed. As this circulation continues, a definite and periodical motion emerges/forms. Its nonlinear features result in the Earth’s motion with simple mechanisms but complex behavior. Ultraterrestrial events may disturb or

关键词： inner-core’s deviation plate novement mantle convection new model of global movement.

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