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Low-complexity transmit antenna selection algorithm for massive MIMO

The Journal of China Universities of Posts and Telecommunications 2020年第5期27卷 63-68页

作者： li Xinmin li guomin liu Yang Guo Tian li Pu li Yarn School of Communication and Information Engineering Xi'an University of Science and TechnologyXi’an 710054China School of Electrical and Control Engineering Xi’an University of Science and TechnologyXi’an 710054China

Massive multiple input multiple output(MIMO)systems can increase capacity and reliability ***,extremely high hardware costs and computational complexity lead to the demand for reasonable antenna *** at the problem that the traditional antenna selection algorithm based on maximizing sum capacity has large complexity and worse bit error rate(BER)performance,a two-step selection algorithm is proposed,which selects a part of the antennas based on the norm-based antenna selection(NBS)firstly,and then selects the antenna based on maximizing capacity via convex *** simulation results show that the improved algorithm has better BER performance than the traditional *** the same time,it reduces computational complexity greatly.

关键词： massive MIMO transmit antenna selection convex optimization

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Evaluation of groundwater quality in the Xinjiang Plain Area

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Frontiers of Environmental Science & Engineering 2010年第2期4卷 183-186页

作者： Jinlong ZHOU Xinguang DONG guomin li Yiping WANG Xiaojing GUO Institute of Geology and Geophysics Chinese Academy of SciencesBeijing 100029China College of Water Conservancy and Civil Engineering Xinjiang Agricultural UniversityUrumqi 830052China School of Environmental Science China University of GeosciencesWuhan 430074China

Groundwater is the main source of drinking water for the urban and rural residents in the plain area of the Xinjiang Uygur Autonomous Region,*** quality of groundwater has a direct relationship with human ***,386 groundwater samples collected from April to August in 2003 were *** samples were collected in basic evaluation units which are determined on the basis of *** dissolved solids,total hardness,pH value,NH3–N,C6H5OH,Chemiluminescence detection of permanganate index(CODMn)and intestinal germ group were evaluated according to the guidelines of Groundwater Quality Standard(GB/T14848-93).The quality of the groundwater in each evaluation unit was classified by using the One Veto Method(a unified approach stipulated by the Ministry of Water Resources).The results indicate that the groundwater in the mainstream area of the Tarim Basin and the Yerqiang River Sub-basin belongs to Category V;the groundwater in the Wulungu River Sub-basin,the KaiduKongque River Sub-basin,the Kashgar River Sub-basin,the Cherchen River Sub-basin and the Hotan River Subbasin belongs to Category IV;the groundwater in the Aibi Lake System belongs to Category II,and the groundwater of other evaluation units belongs to Category *** causes of water quality formation were concisely *** results can be useful for the evaluation and management of water resources in the Xinjiang Plain Area.

关键词： groundwater quality evaluation one veto method total dissolved solids(TDS) pH total hardness

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Recycling and utilization of coal gasification residues for fabricating Fe/C composites as novel microwave absorbents

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International Journal of Minerals,Metallurgy and Materials 2023年第3期30卷 591-599页

作者： guomin li Xiaojie Xue Lutao Mao Yake Wang lingxiao li Guizhen Wang Kewei Zhang Rong Zhang Yuexiang Wang liping liang School of Materials Science and Engineering Taiyuan University of Science and TechnologyTaiyuan 030024China Key Laboratory of Advanced Materials of Tropical Island Resources of Ministry of Education Hainan UniversityHaikou 570228China State Key Laboratory for Coal Conversion Institute of Coal ChemistryChinese Academy of SciencesTaiyuan 030001China China-Belarus Belt and Road Joint Laboratory on Electromagnetic Environment Effect Taiyuan 030032China

Under the background of a transformation of the global energy structure,coal gasification technology has a wide application prospect,but its by-product,the coal gasification residue(CGR),is still not being efficiently utilized for *** CGR contains abundant carbon components,which could be applied to the microwave absorption field as the carbon *** this study,Fe/CGR composites are fabricated via a two-step method,including the impregnation of Fe^(3+)and the reduction *** influence of the different loading capacities of the Fe component on the morphology and electromagnetic properties is ***,the loading content of Fe and the surface morphology of the Fe/CGR can be reasonably controlled by adjusting the concentration of the ferric nitrate ***,Fe particles are evenly inserted on the CGR framework,which expands the Fe/CGR interfaces to enhance interfacial polarization,thus further improving the microwave-absorbing(MA)properties of ***,as the Fe^(3+)concentration is 1.0 mol/L,the Fe/CGR composite exhibits outstanding *** reflection loss reaches-39.3 dB at 2.5 mm,and the absorption bandwidth covers 4.1 GHz at 1.5 *** this study,facile processability,resource recycling,appropriately matched impedance,and excellent MA performance are ***,the Fe/CGR composites not only enhance the recycling of the CGR but also pioneer a new path for the synthesis of excellent absorbents.

关键词： coal gasification residue recycling utilization composite microwave absorption

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B and Fe co-doped Co_(2)P hollow nanocubes for nitrate electroreduction to ammonia

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Chinese Chemical Letters 2024年第2期35卷 278-282页

作者： Jing Miao Qingling Hong liping liang guomin li Zhihong liu Shibin Yin Yu Chen School of Materials Science and Engineering Taiyuan University of Science and TechnologyTaiyuan 030024China School of Materials Science and Engineering Shaanxi Normal UniversityXi'an 710062China School of Chemistry and Chemical Engineering Shaanxi Normal UniversityXi'an 710062China Guangxi Key Laboratory of Electrochemical Energy Materials School of Chemistry and Chemical EngineeringGuangxi UniversityNanning 530004China

Nitrate(NO_(3)^(−))electroreduction reaction(NO_(3)^(−)RR)provides an attractive and sustainable route for NO_(3)^(−)pollution mitigation or energy-saved ammonia(NH3)*** this work,high-quality B and Fe co-doped Co_(2) P hollow nanocubes(B/Fe-Co_(2) P HNCs)are successfully synthesized though simultaneous boronation-phosphorization treatment,which reveal outstanding selectivity,activity,stability for the NO_(3)^(−)to NH_(3) conversion in neutral electrolyte because of big surface area,fast mass transport,superhydrophilic surface,and optimized electronic structure.B/Fe-Co_(2) P HNCs can achieve the high NH3 yield rate(22.67 mg h^(−1) mg_(cat)^(−1))as well as Faradaic efficiency(97.54%)for NO_(3)^(−)RR,greatly outperforming most of non-precious metal based NO_(3)^(−)RR electrocatalysts.

关键词： Nitrate electroreduction reaction Ammonia synthesis Transition metal phosphides Hollow nanocubes

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Effect of Draw Ratio on the Morphologies and Properties of BPDA/PMDA/ODA Polyimide Fibers

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Chemical Research in Chinese Universities 2014年第1期30卷 163-167页

作者： ZHANG Chunling ZHANG Qiong XUE Yanhu li guomin liU Fangfang QIU Xuepeng JI Xiangling GAO lianxun College of Materials Science and Engineering Jilin University Changchun 130025 P. R. China Polymer Composite Engineering Laboratory Chinese Academy of Sciences Changchun 130022 P. R. China State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun 130022 R R. China

3,3,4,4-Biphenyltetracarboxylic dianhydride/pyromellitic dianhydride/4,4-oxydianiline（BPDA/PMDA/ODA） polyimide copolymer fibers with different draw ratios were prepared from the imidization of polyacrylic acid（PAA） fibers via a dry-jet wet-spinning *** morphologies,microcrystal orientations,thermal stabilities,and mechanical properties were investigated via scanning electron microscopy（SEM）,wide angle X-ray diffraction（WAXD）,thermogravimetric analysis（TGA）,and tensile *** order to acquire fibers with better mechanical performance,we aimed at obtaining the optimal draw *** during thermal imidization resulted in a decreased diameter of fiber from 25.8 μm to 16.9 μm corresponding to draw ratio from 1 to *** results show that the degree of the orientation of the undrawn sample is 64.1％,whereas that of the drawn sample is up to 82％.The as-spun fiber and those with different draw ratios all exhibit high thermal stabilities,i.e.,the temperature at a mass loss of 5％ can reach as high as 570 ℃.The tensile strengths and tensile modulus of the fibers increase with the draw ratios,and the maximum tensile strength and modulus are 0.90 and 12.61 GPa,respectively.

关键词： Polyimide Draw ratio Morphology Orientation Mechanical property

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Mobile application for hydrogeologic field investigations

Mobile application for hydrogeologic field investigations

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中国科学院地质与地球物理研究所2014年度（第14届）学术年会

作者： Yanhui Dong guomin li Key Laboratory of Engineering Geomechanics Institute of Geology and GeophysicsChinese Academy of Sciences

An Android application,HyDroid,was developed to help hydrogeologists conduct field *** employing the powerful hardware and operation systems in the Android smartphone,HyDroid not only facilitates geospatial data collection and management,but also helps to conduct some essential hydrogeologic field tests,and to visualize field data instantly.

关键词： Android application Hydrogeologic field investigation Geospatial data collection Internal sensor Google Maps

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Long-Term Evolution of Cones of Depression in Shallow Aquifers in the North China Plain

Long-Term Evolution of Cones of Depression in Shallow Aquife...

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中国科学院地质与地球物理研究所2013年度（第13届）学术年会

作者： Yuan Zhang guomin li Key Laboratory of Engineering Geomechanics Institute of Geology and GeophysicsChinese Academy of Sciences University of Chinese Academy of Sciences

The North China Plain(NCP) is one of the places where the groundwater is most over-exploited in the ***,our understanding on the spatiotemporal variability of the cones of depression in this region is *** study intends to simulate the cones of depression in the shallow aquifer across the entire NCP during the whole period from 1960 to *** the simulation,the dominant role of anthropogenic activities is emphasized and carefully taken into account using a Neural Network *** results show that cones of depression in the NCP were formed in 1970s and continuously expanded. Their centers were getting deeper with an increasing degree of groundwater exploitation. This simulation provides valuable insights for developing more sustainable groundwater management options after the implementation of the South-to-North Water Diversion Project (SNWDP),which is a very important surface water project in China in the near *** numerical model in this paper is built by MODFLOW,with pumpage data completed by neural network algorithm and hydrogeological parameters calibrated by simulated annealing *** on our long-term numerical model for regional groundwater flow in the NCP,one exploitation limitation strategy after the implementation of SNWDP is studied in this *** results indicate that the SNWDP is beneficial for groundwater recovery in the NCP.A number of immense groundwater cones will gradually ***,the recovery of the groundwater environment in the NCP will require a long time.

关键词： numerical simulation South-to-North water diversion neural network algorithm simulated annealing algorithm

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SIMULATION OF SOIL WATER WITH DIFFERENT WATER TABLE DEPTHS UNDER DRIP IRRIGATION ALONG THE TARIM DESERT HIGHWAY,CHINA

SIMULATION OF SOIL WATER WITH DIFFERENT WATER TABLE DEPTHS U...

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中国科学院地质与地球物理研究所2012年度（第12届）学术年会

作者： Xue li guomin li Zhimin Wang Institute of Geology and Geophysics Chinese Academy of Sciences

The Tarim Desert Highway is the main transportation artery in China for oil and gas exploration and development,and is in fact the first and longest graded highway(across the Taklimakan Desert) in the *** suffers from continual sandstorms,and shelterbelts have been built along the road to ensure the smooth, uninterrupted operation of the *** research on the distribution of soil water under drip irrigation in the shelterbelts has great significance for the robust performance of these *** study the role of water table depth in the soil water distribution of the shelterbelts, we established a 2-D saturated-unsaturated flow model,using the software PetraSim,based on *** model was calibrated by sampling data from where the water table depth was 3 m(under drip irrigation conditions) in the center of the Taklimakan *** addition, several scenarios were simulated using different water table *** analyzing the simulation results,some useful conclusions were reached. Our findings showed that soil water distribution is influenced by the irrigation water and groundwater in the shelterbelts along the Tarim Desert ***,the soil-water content with depth takes the form of the letter "C";that is,the water content first decreases and then increases in descending from the surface to the water *** study emphasizes the profound effect of water table depth on the distribution of moisture in the vadose zone,and thus supplies important reference data and provides useful guidelines for research into building an effective irrigation system.

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Identifying Major Factors Affecting Groundwater Change in the North China Plain with Grey Relational Analysis

Identifying Major Factors Affecting Groundwater Change in th...

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中国科学院地质与地球物理研究所2014年度（第14届）学术年会

作者： Xue li guomin li Yuan Zhang Key Laboratory of Engineering Geomechanics Institute of Geology and GeophysicsChinese Academy of Sciences University of Chinese Academy of Sciences National Engineering Research Center of Urban Environmental Pollution Control(The Ministry of Science and Technology of the People's Republic of China) State Environmental Protection Engineering(Beijing)Center for Industrial Wastewater Pollution Control(Ministry of Environmental Protection of the People's Republic of China) Beijing Municipal Research Institute of Environmental Protection

The North China Plain(NCP) is facing a water crisis under the dual impact of natural and anthropogenic *** levels have declined continuously since 1960,causing a series of environmental problems that have restricted sustainable development in the *** the present study,we first utilized a previously developed 3D groundwater model to determine changes in groundwater level in the region over the past 50 years(1961-2010).We then applied grey relational analysis(GRA) to identify and ordinate major factors that have contributed to these *** results show an overall decreasing trend in groundwater levels in this region over the past 50 years and an increase in the water table depth at a rate of approximately 0.36 m/*** exploitation showed the most significant correlation with the groundwater table decline,when compared with other factors including precipitation and river ***,human activities should be considered the primary force driving the groundwater level *** results of this study have implications for developing criteria that consider changes in both climate and ***,since the NCP is one of the most water-scarce and densely populated regions in the world,the analytical approach used in and the insights gained from this study are of international interest.

关键词： grey relational analysis groundwater change North China Plain

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A Single Analysis of Elements in Groundwater(ng L-1to g L-1)by DRC ICP-MS Using Extended Dynamic Range Techniques

A Single Analysis of Elements in Groundwater(ng L-1to g L-1)...

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中国科学院地质与地球物理研究所2015年度（第15届）学术年会

作者： JIANGYI ZHANG WEI GUO guomin li Key Laboratory of Shale Gas and Geoengineering Institute of Geology and GeophysicsChinese Academy of Sciences State Key Laboratory of Biogeology and Environmental Geology China University of Geosciences

Simultaneous determination of elements in groundwater(ng Lto g L)in single analysis by DRC ICP-MS was *** technique of extended dynamic range based on DRC could be able to detune the signal response of selective elements to enable incorporation of high concentration elements(outside of the ion detector’dynamic range to 1e cps)into a single analysis without affecting signal response of other trace *** signal sensitivity of high concentration element(i.e.,K,***,Mg and Fe)was suppressed easily by adjusting the voltage parameters of DRC quadrupole(RPa)and the groundwater samples could be online diluted any multiples(i.e.,from one time to million times)according to the actual *** order to eliminate mass spectral interferences(i.e.,ArCl,ArAr,CAr,CaO,NaAr,MgArandMgAr),the operational conditions of the DRC,working with CH as reaction gas,were optimized forAs,Se,Cr,Ni,Cu *** analytical results of a reference material CASS-5 were in good agreement with the certified *** of the data was also tested by comparing the results for 29 groundwater samples with those determined by ICP-OES and good agreement was obtained for the high concentration *** the routine method in our laboratory,the satisfactory results indicate that it has great potential for the determination of low and high concentration level elements by one single analysis in various samples.

关键词： Extended dynamic range techniques ng L-1 to g L-1 level DRC ICP-MS Groundwater

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