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spatial localization of ECE measurement in EAST LHW-heated plasmas

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Plasma Science and Technology 2019年第9期21卷 39-45页

作者： Yushu ZUO Yong LIU Tianfu ZHOU Hailin ZHAO Yang ZHANG Ang TI Bili LING Liqun HU Institute of Plasma Physics Chinese Academy of Sciences Hefei 230031 People's Republic of China University of Science and Technology of China Hefei 230026 People's Republic of China Istituto di Fisica del Plasma CNR 20125 Milano Italy

In this work, electron cyclotron emission(ECE) is simulated by using the code SPECE to study the spatial localization of ECE measurement in EAST plasmas heated by lower hybrid wave(LHW).The results indicate that generally there are two emission layers for an individual frequency in plasmas with non-thermal electrons, and they are separately attributed to the thermal electrons and non-thermal electrons. The emission layer due to the thermal electrons is nearly identical to that for the case with Maxwellian distribution. The emission layer due to non-thermal electrons is well localized in the location of the non-thermal electrons. Even though the non-thermal emission layer is broader, the emission intensity is smaller than that from the thermal emission layer for the cases studied in this work. Localized electron temperature fluctuations can still be distinguished by ECE measurement as long as it does not coexist with the non-thermal electrons. Sawtooth inversion radii and tearing mode island location determined respectively by the ECE measurement and the soft x-ray measurement for a LHW-heated plasma show a good agreement, and this indicates that the ECE measurement in the plasma core region is not seriously polluted.

关键词： EAST ECE LHW non-thermal electrons spatial localization

spatial and temporal distribution of Mo in the overlying water of a reservoir downstream from mining area

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Journal of Environmental Sciences 2021年第4期33卷 256-262页

作者： Zhixin Song Gangfu Song Wenzhong Tang Yu Zhao Dandan Yan Weilong Zhang School of Environmental and Municipal Engineering North China University of Water Resources and Electric PowerZhengzhou 450011China State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing100049China

This study aimed to evaluate the spatial and temporal variations of molybdenum(Mo)in the downstream water body of a Mo mine during three hydrologic periods(wet,dry and medium seasons).The physical properties in Luhun Reservoir reflected seasonal variations in different hydrological *** redox potential(ORP)and dissolved oxygen(DO)increased in the dry *** concomitant decrease in temperature(T),conductivity(COND)and total dissolved solids(TDS)were lowest in the wet *** p H value did not change significantly during the three hydrologic *** distribution of Mo in the dry season was high in upstream and low in downstream areas,which was significantly different from that of the wet and medium *** total Mo concentration in wet(150.1μg/L)and medium season(148.2μg/L)was higher than that in the dry season,but the TDS(288.3 mg/L)and the percentage dissolved Mo(81.3%)in overlying water was lowest in the wet *** was no significant relationship between the dissolved Mo and the total Mo with *** the dry season,the mean total Mo concentration was 116.3μg/L,which was higher than the standard limit value(70μg/L)for drinking water(US EPA-United States Environmental Protection Agency recommended value 40μg/L).Non-point source pollution is the main characteristic of mining area pollution,which was closely related to ***,the Luhun Reservoir contains substantial Mo pollution,which was a significant concern given that it is used as a source of drinking and irrigation water.

关键词： Seasonal variations spatial Temporal Molybdenum Mining areas

spatial Evolution of Electrostatic Solitary Waves along Plasma Sheet Boundary Layer Adjacent to the Magnetic Reconnection X-Line

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Chinese Physics Letters 2012年第8期29卷 313-317页

作者： LI Shi-You ZHANG Shi-Feng DENG Xiao-Hua CAI Hong College of Aerospace Science and Engineering National University of Defense TechnologyChangsha 410073 Department of Space Physics Wuhan UniversityWuhan 430072 Nanchang University Nanchang 330031

Analysis on the spatial structure of electrostatic solitary waves(ESWs)along the plasma sheet boundary layer(PSBL)near an on-going magnetic reconnection X-line is *** of the ESWs in the PSBL of R3 region near reconnection X-line are propagating earthwards away from the reconnecting *** analysis of their spatial structure shows that,when ESWs propagate along the ambient field in the PSBL,outwards from the magnetic reconnection X-line,their amplitude will finally attenuate and thus the electron hole will fade away but their spatial scale remains ***,the spatial structure of propagating ESWs evolves from 1-D-like to 2-D-like though totally in a 1-D structure.

关键词： spatial propagating structure

spatial heterogeneity in the formation of large deserts in midlatitude Asia revealed by drill core evidence

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Science Bulletin 2024年第22期69卷 3512-3515页

作者： Xin Wang Ziying Yu Chongwen Luo Riqian Guo Han Hu Zaijun Li Fei Wang Baofeng Li Shengqian Chen Shengli Yang Hui Zhao Fahu Chen Key Laboratory of Western China’s Environmental Systems(Ministry of Education) College of Earth and Environmental SciencesLanzhou UniversityLanzhou 730000China Group of Alpine Paleoecology and Human Adaptation(ALPHA) State Key Laboratory of Tibetan Plateau Earth SystemResources and Environment(TPESRE)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China

Deserts are the most distinctive landscapes in the arid zones of midlatitude Asia,producing over 600 Tg of dust annually and serving as primary sources of mineral dust for the Northern *** dust is carried by the westerlies and the East Asian winter monsoon to downwind regions including East Asia,the northern Pacific Ocean,and even Greenland,influencing the global climate,global biogeochemical cycles,ocean productivity,Northern Hemisphere glaciations,and human health.

关键词： latitude spatial winter

spatial context in the calculation of gas emissions for underground coal mines

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International Journal of Mining Science and Technology 2017年第5期27卷 787-794页

作者： Patrick Booth Heidi Brown Jan Nemcik Ren Ting School of Civil Mining and Environmental EngineeringSchool of Earth and Environmental SciencesUniversity of WollongongWollongong 2500Australia

The prediction of gas emissions arising from underground coal mining has been the subject of extensive research for several decades, however calculation techniques remain empirically based and are hence limited to the origin of calculation in both application and resolution. Quantification and management of risk associated with sudden gas release during mining(outbursts) and accumulation of noxious or combustible gases within the mining environment is reliant on such predictions, and unexplained variation correctly requires conservative management practices in response to risk. Over 2500 gas core samples from two southern Sydney basin mines producing metallurgical coal from the Bulli seam have been analysed in various geospatial context including relationships to hydrological features and geological structures. The results suggest variability and limitations associated with the present traditional approaches to gas emission prediction and design of gas management practices may be addressed using predictions derived from improved spatial datasets, and analysis techniques incorporating fundamental physical and energy related principles.

关键词： Gas emission prediction spatial analysis Underground coal mining Risk management Greenhouse gas Climate

spatial distribution analysis on climatic variables in northeast China

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Journal of Environmental Sciences 2001年第2期13卷 247-251页

作者： SHANG Zong-Bo GAO Qiong YANG Dian-An YANG Zheng-Yu Laboratory of Quantitative Vegetation Ecology Institute of Botany The Chinese Academy of Sciences Beijing 100093 China

Information ecology is a new research area of modern ecology. Here describes the spatial distribution analysis methods of four sorts of climatic variables, i.e. temperature, precipitation, relative humidity and sunshine fraction in Northeast China. First, digital terrain models was built with large scale maps and vector data. Then trend surface analysis and interpolation method were used to analyze the spatial distribution of these four kinds of climatic variables at three temporal scale: (1) monthly data; (2) mean monthly data of thirty years, and (3) mean annual data of thirty years. Ecological information system were used for graphics analysis on the spatial distribution of these climatic variables.

关键词： spatial distribution analysis climatic variables trend surface analysis information ecology

spatial and Temporal Evolution of Ultra-Wide-Band Optical Pulses in Propagation

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Chinese Physics Letters 2000年第8期17卷 568-570页

作者： XU Jing-Zhou WANG Li YANG Guo-Zhen Laboratory of Optical Physics Institute of PhysicsChinese Academy of SciencesBeijing 100080

The propagation of ultrashort coherent electromagnetic pulses with broad spectral bandwidth in free space is studied by using scalar diffraction *** is confirmed and experimentally demonstrated that the diffraction not only affects the spatial structure but also changes the temporal waveform of an ultra-wide-band pulse during *** terahertz pulse travelling as basic mode of Gaussian beam is discussed in detail.

关键词： ultrashort spatial travelling

spatial Characteristics of Thomson Scattering Spectra in Laser and Magnetic Fields

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Chinese Physics Letters 2019年第7期36卷 34-38页

作者： Li Zhao Zhi-Jing Chen Hai-Bo Sang Bai-Song Xie Key Laboratory of Beam Technology of the Ministry of Education and College of Nuclear Science and Technology Beijing Normal University Beijing 100875 Beijing Radiation Center Beijing 100875

spatial characteristics of Thomson scattering spectra are studied for an electron moving in the circularly polarized laser field in the presence of a strong uniform magnetic field. The results show that the angular distributions of the spectra with respect to the azimuthal and polar angles exhibit different symmetries, respectively, which depend on the fields and electron parameters sensitively and significantly. Moreover, for relatively large parameters such as high laser intensity, high magnetic resonance parameter as well as large initial momentum of electron, the two lobes in spectra tend to the laser-propagating direction so that the radiation can be collimated in the forward direction. Furthermore, an important finding is that by choosing the appropriate fields and initial momentum of electron, the high frequency part of the Thomson scattering spectra can reach the frequency range of soft x-ray,in which a high radiation power per solid angle as ~10^11 a.u. can be obtained.

关键词： spatial characteristics studied for an electron can be obtained

spatial distribution of the potential forest biomass availability in Europe

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Forest Ecosystems 2019年第1期6卷 56-66页

作者： Pieter Johannes Verkerk Joanne Brighid Fitzgerald Pawan Datta Matthias Dees Geerten Martijn Hengeveld Marcus Lindner Sergey Zudin European Forest Institute University of Freiburg-Institute of Forest Sciences-Chair of Remote Sensing and Landscape Information Systems Wageningen University and Research

Background: European forests are considered a crucial resource for supplying biomass to a growing bio-economy in Europe. This study aimed to assess the potential availability of forest biomass from European forests and its spatial distribution. We tried to answer the questions(i) how is the potential forest biomass availability spatially distributed across Europe and(ii) where are hotspots of potential forest biomass availability located?Methods: The spatial distribution of woody biomass potentials was assessed for 2020 for stemwood, residues(branches and harvest losses) and stumps for 39 European countries. Using the European Forest Information SCENario(EFISCEN) model and international forest statistics, we estimated the theoretical amount of biomass that could be available based on the current and future development of the forest age-structure, growing stock and increment and forest management regimes. We combined these estimates with a set of environmental(site productivity, soil and water protection and biodiversity protection) and technical(recovery rate, soil bearing capacity) constraints, which reduced the amount of woody biomass that could potentially be available. We mapped the potential biomass availability at the level of administrative units and at the 10 km × 10 km grid level to gain insight into the spatial distribution of the woody biomass ***: According to our results, the total availability of forest biomass ranges between 357 and 551 Tg dry matter per year. The largest potential supply of woody biomass per unit of land can be found in northern Europe(southern Finland and Sweden, Estonia and Latvia), central Europe(Austria, Czech Republic, and southern Germany),Slovenia, southwest France and Portugal. However, large parts of these potentials are already used to produce materials and energy. The distribution of biomass potentials that are currently unused only partially coincides with regions that currently have high levels of wood pro

关键词： Forest biomass EFISCEN Europe Potential supply spatial distribution