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Estimating rice paddy areas in China using multi-temporal cloud-free normalized difference vegetation index (NDVI) imagery based on change detection

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Pedosphere 2020年第6期30卷 734-746页

作者： Bolun LI Chaopu ti Xiaoyuan YAN state Key Laboratory of soil and sustainable Agriculture Institute of Soil ScienceChinese Academy of SciencesNanjing 210008China University of Chinese Academy of sciences Beijing 100049China

The spatial pattern of rice paddies is an essential parameter used for studies of greenhouse gas emissions,agricultural resource management,and environmental *** large spatial scales,previous studies have usually mapped rice paddies using a single vegetation index product based on a traditional classification method,or a combined analysis of various vegetation and water indices derived from the moderate resolution imaging spectroradiometer(MODIs)satellite ***,different indices increase the computational cost and constrain the satellite data sources,and traditional classification methods(e.g.,maximum likelihood classification)may be time-consuming and difficult to carry out over a large area like *** this study,we designed an auto-thresholding and single vegetation index(normalized difference vegetation index(NDVI))-based procedure to estimate the spatial distribution of rice paddies in *** MOD09Q1 product,which was available at MODIs’s highest spatial resolution(250 m),was taken as the input *** auto-threshold function was also introduced into the change detection process to distinguish rice paddies from other *** MODIs-derived maps were validated with ground surveys and then compared with China national statistical data of rice paddy *** results indicated that the best classification result was achieved for plain regions,and that the accuracy declined for hilly regions,where the complex landscape could lead to an underestimation of the rice paddy area.A comparison between the modeled results and other analyses using 500-m MODIs data suggests that rice paddies may be identified routinely using a single vegetation index with finer resolution on large spatial scales.

关键词： HANTs algorithm moderate resolution imaging spectroradiometer(MODIs) land surface water index Otsu’s algorithm rice cultivation

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A single-legged Robot Inspired by the Jumping Mechanism of Click Beetles and Its Hopping Dynamics Analysis

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Journal of Bionic Engineering 2020年第6期17卷 1109-1125页

作者： Gang Chen Jiajun Tu Xiaocong ti Huosheng Hu Faculty of Mechanical Engineering and Automation Zhejiang Sci-Tech UniversityHangzhou 310018China school of Computer science and Electronic Engineering University of EssexColchester C043SQUK

The click beetle can jump up with a hinge when it is on the dorsal *** jumping mechanism is simple and suitable as an inspiration for designing a simple,small,and reliable hopping *** report a single-legged robot inspired by the jumping mechanism of click *** is 85 mm high,60 mm long,and 41 mm wide,and weighs about 49 *** robot has good hopping performance that the hopping height is about 4 times-4.3 times of its body *** is capable for rescue missions that require to enter enclosed spaces through cracks and narrow *** addition,hopping dynamics of the robot is important to understand its jumping mechanism and improve the robot’s hopping *** existing dynamic study does not complete the analysis including all stages in the hopping which are pre-hopping,take-off,and *** propose the decomposition method to study dynamics of the three stages separately,and synthesize them with related *** dynamic synthesis of multi-motion states in a hopping cycle of the single-legged hopping robot is *** hopping performance and dynamic synthesis theory of the robot are verified by simulations and *** study helps lay the foundation for design and hopping control of simple hopping robot systems.

关键词： single-legged hopping robots hopping cycle dynamics synthesis multi-motion states jumping mechanism imitaion of click beetles

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Inorganic A‑site cations improve the performance of band‑edge carriers in lead halide perovskites

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Frontiers of Optoelectronics 2023年第3期16卷 115-121页

作者： Cheng Wang Yaoguang Rong ti Wang Key Laboratory of Artifcial Micro-and Nano-structures of Ministry of Education School of Physics and TechnologyWuhan UniversityWuhan 430072China Wuhan National Laboratory for Optoelectronics Huazhong University of Science and TechnologyWuhan 430074China

In lead halide perovskites,organic A-site cations are generally introduced to fne-tune the *** of the questions under debate is whether organic A-site cations are essential for high-performance solar *** this study,we compare the band edge carrier dynamics and difusion process in MAPbBr_(3)and CsPbBr_(3)single-crystal *** transient absorption microscopy,the band-edge carrier difusion constants are *** the replacement of inorganic A-site cations,the difusion constant in CsPbBr_(3)increases almost 8 times compared to that in MAPbBr_(3).This work reveals that introducing inorganic A-site cations can lead to a much larger difusion length and improve the performance of band-edge carriers.

关键词： Perovskite Inorganic cations Carrier difusion

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Graphene Fibers: Advancing Applications in sensor, Energy storage and Conversion

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Chinese Journal of Polymer science 2019年第6期37卷 535-547页

作者： Guan-Hang Yu Qing Han Liang-ti Qu Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials Key Laboratory of Cluster Science Ministry of Education School of Chemistry Beijing Institute of Technology

Graphene fibers are a kind of novel carbon fibers assembled by orderly aligned graphene sheets with high flexibility, good conductivity, high thermal conductivity, and low density, which make them possible to be widely used in high-performance and multifunctional compound materials as well as flexible electronic devices. In this review, we summarize the research progress in the synthesis of graphene fibers, and their applications in sensor, energy storage, and energy conversion. Furthermore, the current issues and some prospects for the future trend of graphene fibers are discussed.

关键词： Graphene fibers Assembly Functionalization sensor Energy storage and conversion

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Hamiltonian Gromov–Witten Invariants on C^n+1 with s^1-action

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Acta Mathematica sinica,English series 2016年第3期32卷 309-330页

作者： ti Yao LI Bo Hui CHEN Department of Mathematics Sichuan University Chengdu 610064 P. R. China school of Mathematical sciences Chongqing Normal University Chongqing 401331 P. R. China Department of Mathematics and Yangtze Mathematical Center Sichuan University Chengdu 610064 P. R. China

Consider a Hamiltonian action of s1 on （Cn^n＋1,ωstd）, we shown that the Hamiltonian Gromov-Witten invariants of it are well-defined. After computing the Hamiltonian Gromov-Witten invariants of it, we construct a ring homomorphism from Hs1,CR（X, R） to the small orbifold quantum cohomology of X//rs^1 and obtain a simpler formula of the Gromov-Witten invariants for weighted projective space.

关键词： Hamiltonian Gromov-Witten invariants orbifold Gromov-Witten invariants weighted projective space

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some Properties of Abnormal Extremals on Lie Groups

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Acta Mathematica sinica,English series 2014年第12期30卷 2119-2136页

作者： ti Ren HUANG Xiao Ping YANG Department of Mathematics Zhejiang Sci-Tech University Department of Applied Mathematics Nanjing University of Science & Technology

Let G be a connected Lie group and D be a bracket generating left invariant *** this paper,first,we prove that all sub-Riemannian minimizers are smooth in Lie groups if the distribution D satisfies [D,[D,D]]D and [K,[K,K]]K for any proper sub-distribution K of ***,we prove that all sub-Riemannian minimizers are smooth in Lie group if the rank-3 distribution D satisfies Condition（B）.Third,we discuss characterizations of normal extremals,abnormal extremals,rigid curves,and minimizers on product sub-riemannian Lie *** prove that not all strictly abnormal minimizers are rigid curves and construct a strictly abnormal minimizer which is not a rigid curve.

关键词： Extremal geodesic rigid curve Lie group

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Dynamic modelling and simulation of a post-combustion CO_(2) capture process for coal-fired power plants

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Frontiers of Chemical science and Engineering 2022年第2期16卷 198-209页

作者： Jianlin Li ti Wang Pei Liu Zheng Li state Key Lab of Power systems International Joint Laboratory on Low Carbon Clean Energy InnovationDepartment of Energy and Power EngineeringTsinghua UniversityBeijing 100084China

solvent-based post-combustion capture technologies have great potential for CO_(2)mitigation in traditional coal-fired power *** and simulation provide a low-cost opportunity to evaluate performances and guide flexible *** by a series of partial differential equations,first-principle post-combustion capture models are computationally expensive,which limits their use in real time process simulation and *** this study,we propose a first-principle approach to develop the basic structure of a reduced-order model and then the dominant factor is used to fit properties and simplify the chemical and physical process,based on which a universal and hybrid post-combustion capture model is *** output at steady state and trend at dynamic state are validated using experimental data obtained from the ***,impacts of liquidto-gas ratio,reboiler power,desorber pressure,tower height and their combination on the absorption and desorption effects are *** indicate that tower height should be designed in conjunction with the flue gas flow,and the gas-liquid ratio can be optimized to reduce the reboiler power under a certain capture target.

关键词： CO_(2)capture post-combustion capture simulation dominant factor

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GIs-based Analysis of Main Air Pollutants of Changchun City in summer

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Chemical Research in Chinese Universities 2006年第4期22卷 447-450页

作者： JING Nan XIA Bin JING ti-song Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 P. R. China Graduate school of Chinese Academy of sciences Beijing 100039 P. R. China College of Environment and Resource Jilin University Changchun 130026 P. R. China

To gain a better understanding of the characteristics of air pollution of Changchun city, P. R. China, in summer, the analytical methods of geographical information system（GIs） and statistical analysis software sPss were applied to the analysis of the monitored concentrations of sO2 , NO2, and O3 in July of 2002 to 2004 in Changchun city. The results obtained show that the average hourly O3 concentrations in July 2002 and 2004 were higher than the firstlevel hourly standard of China. At the same time, the dynamic distribution of the 03 concentration and the relationship between the concentration of 03 and that of NOx were studied. The air quality evaluation result of Changchun city indicates that the southwest of this city was heavily polluted during the monitored period.

关键词： Air pollutant Dynamic distribution Ozone summer of Changchun city GIs

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Measuring relic abundance of minimal dark matter at hadron colliders

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science China(Physics,Mechanics & Astronomy) 2019年第8期62卷 55-74页

作者： QingHong Cao ti Gong KePan Xie Zhen Zhang Department of Physics and state Key Laboratory of Nuclear Physics and Technology Peking University Collaborative Innovation Center of Quantum Matter Center for High Energy Physics Peking University Center for Theoretical Physics Department of Physics and Astronomy Seoul National University

We consider the special case that the dark matter(DM) candidate is not detected in direct-detection programs when the experimental sensitivity reaches the neutrino flux background. In such circumstance the DM searches at the colliders impose constraints on the DM relic abundance if the DM candidate is a WIMPs type. specifically, we consider the triplet(quintet and septet) DMs in the framework of minimal DM model and explore the potential of discovering the DM candidate in the mono-jet, mono-photon and vector boson fusion channels at the Large Hadron Collider(LHC) and future 100 TeV hadron collider. If the DM candidate in such a scenario is discovered at the LHC, then additional DM candidates are needed to explain the observed relic *** the other hand, null results in those DM searching programs at the colliders give rise to lower limits of DM relic abundance.

关键词： dark matter electro weak interactions hadron colliders

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super-resolution imaging in glycoscience: New developments and challenges

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Journal of Innovative Optical Health sciences 2016年第3期9卷 19-34页

作者： Junling Chen ti Tong Hongda Wang state Key Laboratory of Electroanalytical Chemistry Changchun Institute of Applied Chemistry Chinese Academy of sciences Changchun Jilin 130022P.R.China University of Chinese Academy of sciences Beijing 100049 P.R.China Department of Thoracic surgery The second Hospital of Jilin University Changchun Jilin 130041 P.R.China

Carbohydrates on cell surfaces play a crucial role in a wide variety of biological processes,including cell adhesion,recognition and signaling,viral and bacterial infection,in°ammation and ***,owing to the large diversity and complexity of carbohydrate structure and nongenetically synthesis,glycoscience is the least understood¯eld compared with genomics and *** the structures and functions of carbohydrates have been investigated by various conventional analysis methods,the distribution and role of carbohydrates in cell membranes remain *** review focuses on the developments and challenges of super-resolution imaging in glycoscience through introduction of imaging principle and the available°uorescent probes for super-resolution imaging,the labeling strategies of carbohydrates,and the recent applications of super-resolution imaging in glycoscience,which will promote the super-resolution imaging technology as a promising tool to provide new insights into the study of glycoscience.

关键词： Carbohydrate super-resolution imaging

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