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Effect of interplanetary shock on an ongoing substorm:Simultaneous satellite-ground auroral observations

Science China(technological Sciences) 2023年第3期66卷 654-662页

作者： LIU JianJun CHEN XiangCai WANG ZhiQiang HU ZeJun ZHAO XingXin HU HongQiao HAN DeSheng LUI A.T.Y Ministry of Natural Resources(MNR) Key Laboratory for Polar SciencePolar Research Institute of ChinaShanghai 200136China Antarctic Zhongshan National Field Observation and research station for Snow and Ice Space Special Environment and DisastersPolar Research Institute of ChinaShanghai 200136China College of Astronautics Nanjing University of Aeronautics and AstronauticsNanjing 211106China Institute of Space Physics and Applied Technology Peking UniversityBeijing 100871China State Key Laboratory of Marine Geology School of Ocean and Earth ScienceTongji UniversityShanghai 200092China Applied Physics Laboratory Johns Hopkins UniversityLaurelMarylandUSA

Substorm processes have been studied in detail,and it is well known that interplanetary(IP)shock encountering the terrestrial magnetosphere causes global ***,how IP shock compression to the magnetosphere affects the development of an ongoing substorm remains ***,the simultaneous satellite and ground-based auroral evolutions associated with an IP shock impact on the magnetopause during an ongoing substorm on May 7th,2005,were *** IMAGE satellite over the Southern Hemisphere captured the global development substorm,which was initiated at 17:38:47 *** poleward branch of the nightside auroral oval was fortuitously monitored by an all-sky camera at the Zhongshan station(-74.5°magnetic latitude,ZHO)in *** satellite imager observed continuous brightening and broadening of the nightside auroral oval after the IP shock *** simultaneous ground-based optical aurora measurement displayed the intensification and expansion of a preexisting auroral surge poleward of the aurora *** geomagnetic field variations and the instantly increased PC indices indicated an elevated merging rate and enhanced the convection-related DP-2 ***,this IP shock transient impact did not significantly change the ongoing development of the substorm,although it meets the magnetospheric precondition hypothesis.

关键词： interplanetary shock substorm global auroral images all-sky camera Zhongshan station

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Current Situation and Development Proposals of Agricultural Facilities(Planting)Application in Beijing

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Journal of Beijing Institute of Technology 2023年第3期32卷 275-284页

作者： Xihong Lei Wei Li Yanfang Wang Manli Niu Fudong Wang Dong An Liguo Yang Beijing Agricultural Technology Extension station Beijing 100029China College of Information and Electrical Engineering China Agricultural UniversityBeijing 100083China

Facility agriculture is an essential carrier for promoting stable production and ***2020,the planting area of facility agriculture in Beijing(290098000 m2)accounted for 29.06%of the total planting area of crops(998078000 m2),and the output value accounted for 46.56%.In2022,Beijing Agricultural Technology Extension station organized relevant departments to summarize and evaluate the agricultural facilities in Beijing through consultation materials,interviews,questionnaires,and field trips,combining survey data and statistical data to draw the following *** play a major supporting role in stabilizing production and ensuring *** number of traditional greenhouses is extensive and covers a large area,so special planning and classification upgrades are urgently *** are rich in scientific and technological resources,but the mode of production is out of *** is of great significance to improve the comprehensive production capacity of facility agriculture and promote the healthy and stable development of facility industry in Beijing to increase the utilization rate of facility agriculture land,strengthen the support of facility science and technology,and cultivate the socialized service organization of facility.

关键词： facility agriculture stable production and supply cost benefit technical support

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A switchable concentrating photovoltaic/concentrating solar power(CPV/CSP)hybrid system for flexible electricity/thermal generation

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Science China(technological Sciences) 2023年第8期66卷 2332-2345页

作者： PAN XinYu YUAN MengDi JU Xing XU Chao Key Laboratory of Power station Energy Transfer Conversion and System of Ministry of Education School of Energy Power and Mechanical EngineeringNorth China Electric Power UniversityBeijing 102206China

Due to the intermittency and indeterminacy of solar irradiance,balancing energy supply and load demand remains a *** paper proposed a switchable hybrid system that combines concentrating photovoltaic/concentrating solar power(CPV/CSP)technology with thermal energy storage(TES)to achieve flexible electricity and thermal generation by adjusting the incident solar flux of photovoltaic(PV).The hybrid system can directly transfer surplus solar energy into high-quality heat for storage using a rotatable PV/heat *** simulated results demonstrated that the hybrid system effectively improves power generation,optimally utilizes TES capacity,and reduces the levelized cost of electricity(LCOE).Over a selected seven-day period,the single-junction(1J)Ga As solar cells used in the hybrid system sustainably satisfied the load demand for more than five days without grid supplement,outperforming the CSP plant by an additional two *** hybrid system utilizing the 1J Ga As with the base configuration of solar multiple(SM)of 1.26 and TES capacity of 5 h improved the annual power production and renewable penetration(RP)by 20.8%and 24.8%compared with the conventional CSP plant,*** hybrid plant with monosilicon and a configuration of SM(1.8),PV ratio(1),and TES capacity(6 h)achieved an optimal LCOE of11.52$ct/k Wh and RP of 75.5%,which is 8.8%lower and 12.1%higher than the CSP plant,respectively.

关键词： concentrated photovoltaic concentrated solar power hybrid system flexible electricity/thermal ratio techno-economic analysis

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Examining the efficacy of revegetation practices in ecosystem restoration programs:insights from a hotspot of sandstorm in northern China

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Frontiers of Earth Science 2021年第4期15卷 922-935页

作者： Ziqiang DU Rong RONG Zhitao WU Hong ZHANG Institute of Loess Plateau Shanxi UniversityTaiyuan 030006China 2 Shanxi Key Laboratory for Ecological restoration of Loess Plateau Taiyuan 030006China Field Scientific Observation and research station of the Ministry of Education of Shanxi Subalpine Grassland Ecosystem Taiyuan 030006China College of Environmental&Resource Sciences Shanxi UniversityTaiyuan 030006China

Retrospectively evaluating the efficacy of revegetation practices is helpful in planning and imple-menting future ecosystem restoration programs(ERP).Having a good understanding of how human activities can affect vegetation cover,both before and after ERP,is particularly important in sandstorm hotspot *** Beijing-Tianjin Sandstorm Source Region(BTSSR)is one such *** conducted an investigation into vegetation dynamics within the *** was done using remote sensing data in conjunction with climate data sets and land use data spanning the 1982-2014 *** relationships between climatic factors(such as precipitation and temperature),and vegetative change were modeled using a neural network *** a process of residual analysis,the proportions of human-induced vegetative change both before and after the ERP were *** results show that:1)before the ERP(1982-2000),40.96%of the study area exhibited significantly progressive vegetation changes(p<0.05).This proportion decreased to encom-pass only 20.23%of the study area in the period following the ERP(2001-2014).2)89.55%of the study area showed signs of human-induced vegetation degradation before the *** 2001 and 2014 however,following ERP,this figure fell to only 27.78%.3)ERP implementation led to visible improvements in vegetative conditions within the BTSSR,especially in areas where ecological restoration measures were directly and anthropogenically *** results highlight the benefits that positive human action(i.e.,revegetation initiatives implemented under the framework of an ERP)have brought to the BTSSR.

关键词： vegetation dynamics human activities ERP neural network model Beijing-Tianjin sandstorm source region

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Active plane modulation of Bi_(2)O_(3)nanosheets via Zn substitution for efficient electrocatalytic CO_(2)reduction to formic acid

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Nano research 2023年第8期16卷 10803-10809页

作者： Yumei Liu Tiantian Wu Hongfei Cheng Jiawen Wu Xiaodong Guo Hong Jin Fan College of Chemical Engineering Sichuan UniversityChengdu 610065China School of Physical and Mathematical Sciences Nanyang Technological UniversitySingapore 637371Singapore School of Chemistry Xi’an Key Laboratory of Sustainable Energy Materials ChemistryState Key Laboratory of Electrical Insulation and Power EquipmentXi’an Jiaotong UniversityXi’an 710049China Institute of Materials research and Engineering A*STAR2 Fusionopolis WaySingapore 138634Singapore

Formic acid is considered one of the most economically viable products for electrocatalytic CO_(2)reduction reaction(CO_(2)RR).However,developing highly active and selective electrocatalysts for effective CO_(2)conversion remains a grand ***,we report that structural modulation of the bismuth oxide nanosheet via Zn^(2+)cooperation has a profound positive effect on exposure of the active plane,thereby contributing to high electrocatalytic CO_(2)RR *** obtained Zn-Bi_(2)O_(3)catalyst demonstrates superior selectivity towards formate generation in a wide potential range;a high Faradaic efficiency of 95%and a desirable partial current density of around 20 mA·cm^(-2)are obtained at−0.9 V(*** hydrogen electrode(RHE)).As proposed by density functional theory calculations,Zn substitution is the most energetically feasible for forming and stabilizing the key OCHO*intermediate among the used metal ***,the more negative adsorption energy of OCHO*and the relatively low energy barrier for the desorption of HCOOH*are responsible for the enhanced activity and selectivity.

关键词： electrocatalytic CO_(2)reduction Bi_(2)O_(3)catalyst active plane modulation Zn substitution high selectivity

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research Progress of Soil Microbiology

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Agricultural Science & Technology 2015年第11期16卷 2367-2371页

作者： Lide WANG Tuo YAO Chunxiu GUO Fugui HAN Fangling WANG Tao SUN Yinhua ZHANG Gansu Desert Control research Institute Pratacultural College of Gansu Agricultural University Minqin National station for Desert Steppe Ecosystem Studies State Key Laboratory Breeding Base of Desertification and Aeolian Sand Disaster Combating Gansu Hexi Corridor Forest Ecosystem National research station

This paper aims at summarized the research progress of soil microbes,in amount of soil microbes including bacteria,fungi and actinomycetes,soil microbial biomass,including microbial biomass carbon,microbial biomass nitrogen and microbial biomass phosphorus,function of microbial and screening and application of beneficial microorganisms etc.,and future research are discussed combined with our project team for many years of work.

关键词： Soil Microbiology Soil microbes Microbial biomass research progress

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The water-saving potential of using micro-sprinkling irrigation for winter wheat production on the North China Plain

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Journal of Integrative Agriculture 2021年第6期20卷 1687-1700页

作者： ZHAI Li-chao LU Li-hua DONG Zhi-qiang ZHANG Li-hua ZHANG Jing-ting JIA Xiu-ling ZHANG Zheng-bin Institute of Cereal and Oil Crops Hebei Academy of Agriculture and Forestry Sciences/Scientific Observing and Experimental Station of Crop Cultivation in the North ChinaMinistry of Agriculture and Rural AffairsShijiazhuang 050035P.R.China Center for Agricultural Resources research Institute of Genetics and Development BiologyChinese Academy of SciencesShijiazhuang 050021P.R.China

The shortage of groundwater resources is a considerable challenge for winter wheat production on the North China ***-saving technologies and procedures are thus urgently *** determine the water-saving potential of using micro-sprinkling irrigation(MSI)for winter wheat production,field experiments were conducted from 2012 to *** to traditional flooding irrigation(TFI),micro-sprinkling thrice with 90 mm water(MSI1)and micro-sprinkling four times with 120 mm water(MSI2)increased the water use efficiency by 22.5 and 16.2%,respectively,while reducing evapotranspiration by 17.6 and 10.8%.Regardless of the rainfall pattern,MSI(i.e.,MSI1 or MSI2)either stabilized or significantly increased the grain yield,while reducing irrigation water volumes by 20–40%,compared to *** the same volumes of irrigation water,MSI(i.e.,MSI3,micro-sprinkling five times with 150 mm water)increased the grain yield and water use efficiency of winter wheat by 4.6 and 11.7%,respectively,compared to *** MSI could supply irrigation water more frequently in smaller amounts each time,it reduced soil layer compaction,and may have also resulted in a soil water deficit that promoted the spread of roots into the deep soil layer,which is beneficial to photosynthetic production in the critical *** conclusion,MSI1 or MSI2 either stabilized or significantly increased grain yield while reducing irrigation water volumes by 20–40%compared to TFI,and should provide water-saving technological support in winter wheat production for smallholders on the North China Plain.

关键词： winter wheat grain yield water use efficiency micro-sprinkling irrigation traditional flooding irrigation water-saving potential

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Time synchronization in communication networks based on the Beidou foundation enhancement system

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Science China(technological Sciences) 2016年第1期59卷 9-15页

作者： LIU Hui ZHANG RuFei LIU JingNan ZHANG Ming GNSS research Center Wuhan University

Communication networks rely on time synchronization information generated by base station equipment(either the Global Navigation Satellite System receiver or rubidium atomic clock) to enable wireless networking and communications. Meanwhile, the time synchronization among base stations depends on the Network Time Protocol. With the development of mobile communication systems, the corresponding time synchronization accuracy has increased as well. In this case, the use of sparsely distributed-high-precision synchronization points to synchronize time for an entire network with high precision is a key problem and is the foundation of the enhanced network communication. The current receiver equipment for China's digital synchronous network typically includes dedicated multi-channel GPS receivers for communication; however, with the development of GPS by the USA, network security has been destabilized and reliability is low. Nonetheless, network time synchronization based on Beidou satellite navigation system timing devices is an inevitable development trend for China's digital communications network with the establishment of the independently developed BDS, especially the implementation and improvement of the Beidou foundation enhancement system.

关键词： Beidou satellite navigation system precision timing time synchronization Beidou foundation enhancement system communication network time synchronization

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Towards smart farming solutions in the *** South Korea:A comparison of the current status

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Geography and Sustainability 2021年第4期2卷 312-327页

作者： Susan A.O’Shaughnessy Minyoung Kim Sangbong Lee Youngjin Kim Heetae Kim John Shekailo USDA-ARS Conservation and Production Research Laboratory2300 Experiment Station RDBushlandTexas USA 79012 R&D Coordination Division Rural Development Administration54875Republic of Korea National Institute of Agricultural Sciences Rural Development Administration54875Republic of Korea USDA-ARS Office of International Research Engagement and CooperationBeltsvilleMD 20705

Smart farming solutions combine information,data software tools,and technology with the intent to improve agricultural *** smart farming concepts are well described in the literature,the potential societal impacts of smart farming are less *** demonstrate how smart farming solutions could influence future agricultural production,agri-business and rural communities and their constituents,this article compares smart farming approaches and reasons behind the pursuit of smart farming solutions by the *** South *** article compares agricultural assets and productivity among the two countries as well as the technical and societal challenges impacting agricultural production as a basis to understanding the motivations behind and pathways for developing smart farming *** doing so,the article compares some of the technological and social advantages and disadvantages of smart farming,dependending on the choice and implementation of smart farming *** South Korean government has implemented a national policy to establish smart farming communities;a concept that addresses the entire agri-food supply *** the U.S.,a national plan to develop smart farming technologies does not ***,discrete smart farming solutions driven mainly by competition in the private sector have resulted in high-tech solutions that are advancing smart farming *** differences in approaches and reporting of successes and failures between the two countries could facilitate the rate of evolution of successful smart farming solutions,and moreover,could provide pathways to facilitate sustainable development goals in developing countries where smart farming activities are currently underway.

关键词： Agri-food Climate change Information technology Sustainable agriculture

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Countermeasures for Solving the Environmental Problems and Accelerating the Model City Construction of Xi'an

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Meteorological and Environmental research 2014年第2期5卷 55-58,62页

作者： Liu Zhenxiang Song Ting Ma Longbao Environmental Monitoring station of Xi'an

Through careful study, it found that the key and difficult points of affecting and restricting Xi＇an to reach the model city construction standards in provincial and national levels were ＂urban air environment quality standards＂ and ＂water qualification rate of urban water environment function area＂. In order to tackle with the weak links, highlight the important points and focus on the difficult points to strengthen scientific and technological innovation, we actively explored new ideas and ways to resolve the dilemma in meeting the two standards of model city construction, and we managed to put forward the countermeasures to resolve the dilemma through innovating system and mechanism. ＂Place master system＂ should be carded out quickly to meet the ＂urban air environment quality standards＂, while ＂river master system＂ should be implemented as soon as possible to reach the ＂water qualification rate of urban water environment function area＂. The aim of this study was to enhance the qualification rates of the indicators for model city construction to make Xi＇an successfully pass the provincial and national assessment of model city construction through dealing with the weak links to accelerate the realization of becoming model environmental protection city.

关键词： Model environmental protection city construction Countermeasures Environmental problems China

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