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Simulation study of the performance of the Very Large Area gamma-ray Space Telescope

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Nuclear Science and Techniques 2024年第9期35卷 1-17页

作者： Xu Pan Wei Jiang chuan yue Shi-Jun Lei yu-Xin Cui qiang yuan Key Laboratory of Dark Matter and Space Astronomy Purple Mountain ObservatoryChinese Academy of SciencesNanjing 210023China School of Astronomy and Space Science University of Science and Technology of ChinaHefei 230026China

The Very Large Area gamma-ray Space Telescope(VLAST)is a mission concept proposed to detect gamma-ray photons through both Compton scattering and electron–positron pair production mechanisms,thus enabling the detection of photons with energies ranging from MeV to *** project aims to conduct a comprehensive survey of the gamma-ray sky from a low-Earth orbit using an anti-coincidence detector,a tracker detector that also serves as a low-energy calorimeter,and a high-energy imaging *** developed a Monte Carlo simulation application of the detector using the GEANT4 toolkit to evaluate the instrument performance,including the effective area,angular resolution,and energy resolution,and explored specific optimizations of the detector *** simulation-based analysis indicates that the current design of the VLAST is physically feasible,with an acceptance above 10 m^(2)sr which is four times larger than that of the Fermi-LAT,an energy resolution better than 2%at 10 GeV,and an angular resolution better than 0.2◦at 10 *** VLAST project promises to make significant contributions to the field of gamma-ray astronomy and enhance our understanding of the cosmos.

关键词： Space astronomy Gamma-ray telescope Calorimeter Monte Carlo simulation

Hydrocarbon gas huff-n-puff optimization of multiple horizontal wells with complex fracture networks in the M unconventional reservoir

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Petroleum Science 2024年第2期21卷 1018-1031页

作者： Hao-chuan Zhang Yong Tang You-Wei He Yong Qin Jian-Hong Luo yu Sun Ning Wang De-qiang Wang State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu610500SichuanChina CNPC Research Institute of Petroleum Exploration&Development Beijing100083China Southwest Oil&Gas Field Company PetroChinaChengdu610051SichuanChina State Key Laboratory of Offshore Oil Exploitation CNOOC Research Institute Co.LtdBeijing100027China

The oil production of the multi-fractured horizontal wells(MFHWs) declines quickly in unconventional oil reservoirs due to the fast depletion of natural energy. Gas injection has been acknowledged as an effective method to improve oil recovery factor from unconventional oil reservoirs. Hydrocarbon gas huff-n-puff becomes preferable when the CO_(2) source is limited. However, the impact of complex fracture networks and well interference on the EOR performance of multiple MFHWs is still unclear. The optimal gas huff-n-puff parameters are significant for enhancing oil recovery. This work aims to optimize the hydrocarbon gas injection and production parameters for multiple MFHWs with complex fracture networks in unconventional oil reservoirs. Firstly, the numerical model based on unstructured grids is developed to characterize the complex fracture networks and capture the dynamic fracture ***, the PVT phase behavior simulation was carried out to provide the fluid model for numerical simulation. Thirdly, the optimal parameters for hydrocarbon gas huff-n-puff were obtained. Finally, the dominant factors of hydrocarbon gas huff-n-puff under complex fracture networks are obtained by fuzzy mathematical method. Results reveal that the current pressure of hydrocarbon gas injection can achieve miscible displacement. The optimal injection and production parameters are obtained by single-factor analysis to analyze the effect of individual parameter. Gas injection time is the dominant factor of hydrocarbon gas huff-n-puff in unconventional oil reservoirs with complex fracture networks. This work can offer engineers guidance for hydrocarbon gas huff-n-puff of multiple MFHWs considering the complex fracture networks.

关键词： Unconventional oil reservoir Complex fracture network Hydrocarbon gas huff-n-puff Parameter optimization Numerical simulation

Harmful evaluation of heavy metals from soil layer to the groundwater: Take the Jilin Hunchun Basin as an example

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China Geology 2024年第1期7卷 116-124页

作者： Xiao-Dong Guo qiang Liu Hui-Rong Zhang Xu-Fei Shi chuan-yu Qin Zhi-qiang Zhang Shenyang Geological Survey Center China Geological SurveyMinistry of Natural ResourcesShenyang 110034China Key Laboratory of Black Land Evolution and Ecological Effects Shenyang 110034China New Energy and Environment College Jilin UniversityChangchun 130026China Jilin Hydrogeological Survey Institute Changchun 130026China

The continuous enrichment of heavy metals in soils has caused potential harm to *** methods to evaluate the harm of heavy metals in soil to groundwater are lacked in previous *** on the theory of groundwater circulation and solid-liquid equilibrium,a simple and easy-touse flux model of soil heavy metals migrating to groundwater is *** on groundwater environmental capacity,an innovative method for evaluating the harm of heavy metals in soil to groundwater is proposed,which has been applied in Hunchun Basin,Jilin Province,*** results show that the fluxes of soil heavy metals into groundwater in the study area are Zn,Cu,As,Pb,Cd,Ni,and Hg in descending *** content of heavy metals in groundwater(As,Hg,Cu,Pb,Zn,Ni,and Cd)in most areas has not risen to the threshold of environmental capacity within 10 *** harm levels of soil heavy metals to groundwater in the most townships soils are at the moderate level or *** evaluation method can quantify the flux of soil heavy metals into groundwater simply and quickly,determine the residual capacity of groundwater to heavy metals,evaluate the harm level of soil heavy metals to groundwater,provide support for relevant departments to carry out environmental protection of soil and groundwater,and provide a reference to carry out similar studies for related scholars.

关键词： Soil heavy metals As+Hg+Cu+Pb+Zn+Ni+Cd Environmental capacity Groundwater Hazard degree Migration flux model Agricultural geological survey engineering Hunchun Basin Jilin Province

Statistical analysis and interpretation on lightning impulse breakdown voltages of ester liquids under varying field uniformity

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High Voltage 2024年第1期9卷 22-34页

作者： Haichuan yu qiang Liu Zhongdong Wang Department of Electrical and Electronic Engineering The University of ManchesterManchesterUK Department of Engineering University of ExeterExeterUK

Ester liquids(ELs),as the alternative transformer liquids to the conventional mineral oils(MOs),have been increasingly used in power transformers with high voltage *** various properties,the lightning impulse breakdown voltages(LIBDVs)have been studied elaborately in the past two decades under different electric field *** electric field uniformities do have an effect on the breakdown characteristics,for example,breakdown mechanisms,polarity effects,and differences of LIBDV between ELs and MOs,which is quantitatively investigated based on the LIBDVs collected from the *** breakdown mechanism transition phenomenon between streamer initiation dominated breakdown and streamer propagation dominated breakdown has been reviewed ***,the transition field factor boundaries to observe the polarity effect on LIBDVs are taken at around 20 for ELs and 10 for ***,the transition field factor boundaries to observe the LIBDV distinctions between ELs and MOs are about 109 and 14 under positive and negative lightning impulse,*** systematic analysis and interpretation on the transition field factor boundaries among different phenomena can provide insights on insulation design of ELs filled power transformers.

关键词： field lightning breakdown

Genome-wide analysis of Panonychus citrimicro RNAs witha focus on potential insecticidal activity of 4 micro RNAs toeggs and nymphs

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Insect Science 2024年第2期31卷 354-370页

作者： chuan-Zhen Li yu-Hang Liu Deng Pan Meng-Hao Xia qiang Zhang yu-chuang Li Guo-Rui yuan Jin-Jun Wang Wei Dou Key Laboratory of Entomology and Pest Control Engineering College of Plant ProtectionAcademy of Agricultural SciencesSouthwestUniversityChongqingChina Key Laboratory of Agricultural Biosafety and Green Production of Upper Yangtze River(Ministry of Education) Academy of Agricultural SciencesSouthwest UniversityChongqingChina

Panonychus citriMcGregor(Acari:Tetranychidae),a destructive citrus pest,causes considerable annual economic losses due to its short lifespan and rapid ***(miRNA)-induced RNA interference is a promising approachfor pest control because of endogenous regulation of pest growth and *** for miRNAs with potential insecticidal activity ***,genome-wide analysis ofmiRNAs at different developmental stages was conducted,resulting in the identificationof 136 miRNAs,including 73 known and 63 novel miRNAs.A total of 17 isomiRNAsand 12 duplicated miRNAs were ***-1 and miR-252-5p were identified asreference miRNAs *** *** on differential expressionanalysis,treatments with miR-let-7a and miR-315 mimics and the miR-let-7a antagomirsignificantly reduced the egg hatch rate and resulted in abnormal egg ***-expression or downregulation of miR-34-5p and miR-305-5p through feeding significantlydecreased the adult eclosion rate and caused molting *** 4 miRNAs,miR-let-7a,miR-315,miR-34-5p,and miR-305-5p,had important regulatory functions and insectici-dal properties in egg hatching and adult *** general,these data advance our un-derstanding of miRNAs in mite biology,which can assist future studies on insect-specificmiRNA-based green pest control technology.

关键词： growth and development microRNAs Panonychus citri referencemiRNAs regulation small RNA libraries

One more step to realistic CO_(2) reduction reactions——geometric structures evolutions at gas-solid interface

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Rare Metals 2024年第2期43卷 849-852页

作者： Ya-qiang Xie Xin yu Ting Wang College of the Environment and Ecology Xiamen UniversityXiamen361102China

A rational design of copper(Cu)nanocatalyst is critical to the efficient carbon dioxide(CO_(2))conversion toward C1/C2 chemical ***,the lack of actual information on the vicinal Cu interfaces hinders the intrinsic activitystructure correlation *** with atomic-scale in situ characterizations(AP-STM and synchrotron-based AP-XPS),Park and co-workers study and identify the adsorbate-driven morphological evolution of Cu nanoclusters on the Cu(997)surface,providing real-space evidence for the critical role of vicinal structures on Cu *** observed surface roughening trends caused by dissociated atomic oxygen and CO adsorbates subsequently affect the result of successive catalytic reactions to produce critical intermediates,such as carbonate and formate,during the CO_(2)reduction reaction.

关键词： reaction critical rational

Nutrient enrichment driven by canopy rainfall redistribution:Mechanism,quantification,and pattern

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Science China Earth Sciences 2024年第5期67卷 1529-1544页

作者： chuan yuAN Xiaoping yuE Yafeng ZHANG yu ZHANG Yanting HU qiang TANG Li GUO Shuai WANG Xingwu DUAN Wenhua XIANG Xiaohua WEI Xiaoyan LI College of Forestry and Biotechnology Zhejiang A&F UniversityHangzhou 311300China Chongqing Jinfo Mountain Karst Ecosystem National Observation and Research Station School of Geographical SciencesSouthwest UniversityChongqing 400715China Shapotou Desert Research and Experiment Station Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China School of Geographical Sciences Hebei Normal UniversityShijiazhuang 050024China Faculty of Life Science and Technology Central South University of Forestry and TechnologyChangsha 410004China State Key Laboratory of Hydraulics and Mountain River Engineering College of Water Resource and HydropowerSichuan UniversityChengdu 610065China State Key Laboratory of Earth Surface Processes and Resource Ecology Faculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China yunnan Key Laboratory of Soil Erosion Prevention and Green Development Institute of International Rivers and Eco-securityYunnan UniversityKunming 650091China Department of Earth Environmental and Geographic SciencesUniversity of British Columbia(Okanagan)KelownaBritish Columbia V1V 1V7Canada

Vegetation canopies intercept and redistribute rainfall into throughfall and stemflow,which transfer substantial amounts of elements into the soil,influencing soil microbial community,plant survival,and plant community *** advancements in ecohydrological research,the implication of nutrient enrichment resulting from this redistribution of rainfall by canopies remains largely *** address this gap,we conducted a systematic review of 1020 papers published between 2000 and 2022,gathering data on nutrient concentration and enrichment for critical ions(including K^(+),Na^(+),Ca^(2+),Mg^(2+),NH_(4)^(+),Cl^(-),NO_(3)^(-)and SO_(4)^(2-))from the Web of Science and Chinese Knowledge Infrastructure *** aimed to synthesize the mechanisms,quantify the enrichments,and identify global patterns of nutrient enrichment in stemflow and throughfall across climate zones,and vegetation types and *** results of this study indicate that stemflow exhibits,on average,2.1times greater ion concentration(6.13 mg L^(-1))compared to *** particular,among the investigated ions,SO_(4)^(2-)(12.45and 6.32 mg L^(-1))for stemflow and throughfall,respectively,and Cl^(-)(9.21 and 4.81 mg L^(-1))exhibit the highest concentrations in both rainfall redistribution components,while K^(+)(13.7 and 5.8)and Mg^(2+)(5.6 and 2.8)have the highest enrichment *** climate zones,throughfall and stemflow show the lowest ion concentrations but the highest enrichment factors in extremely humid *** the temperature gradient,ion concentrations are the highest in cold climates with no clear patterns observed for enrichment factors with increasing *** addition,shrubs,conifers,mixed forests,and artificial ecosystems demonstrate enrichment factors 1.1 to 3.0 times greater than those of trees,broad-leaved plants,pure forests,and natural *** findings emphasize the need for increased attentions to artificial ecosystems,such as urban

关键词： Ecohydrology Rainfall redistribution Nutrients transport Enrichment characteristics Climate zones

Indian monsoon drove the dispersal of the thoracica group of Scytodes spitting spiders

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Zoological Research 2024年第1期45卷 152-159页

作者： yu-Fa Luo Shu-qiang Li School of Life and Environmental Sciences Shaoxing UniversityShaoxingZhejiang 312000China Key Laboratory of Zoological Systematics and Evolution Institute of ZoologyChinese Academy of SciencesBeijing 100101China Southeast Asia Biodiversity Research Institute Chinese Academy of SciencesYezinNay Pyi Taw 05282Myanmar

We examined the global biogeography of the Scytodes thoracica group of spitting spiders based on 23 years of sampling at the species level(61 species in the thoracica group and 84 species of Scytodes)using DNA data from six *** results indicated that the thoracica group initially dispersed from Southeast Asia to East Africa between 46.5 and 33.0 million years ago,and dispersal events intensified between Southeast/South Asia and East/South Africa from the early to late *** timing of these events indicates that Asian-African faunal exchange of the thoracica group was driven by the Indian monsoon,and the pattern of dispersal suggests that colonialization took root when the Indian monsoon shifted from a North-South direction to an East-West direction from the middle Eocene.

关键词： Geological event Climate change Ballooning organism Faunal exchange Species distribution

A comprehensive review on microchannel heat sinks for electronics cooling

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International Journal of Extreme Manufacturing 2024年第2期6卷 133-162页

作者： Zhi-qiang yu Mo-Tong Li Bing-Yang Cao Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Engineering MechanicsTsinghua UniversityBeijing 100084People’s Republic of China

The heat generation of electronic devices is increasing dramatically,which causes a serious bottleneck in the thermal management of electronics,and overheating will result in performance deterioration and even device *** the development of micro-machining technologies,the microchannel heat sink(MCHS)has become one of the best ways to remove the considerable amount of heat generated by high-power *** has the advantages of large specific surface area,small size,coolant saving and high heat transfer *** paper comprehensively takes an overview of the research progress in MCHSs and generalizes the hotspots and bottlenecks of this *** heat transfer mechanisms and performances of different channel structures,coolants,channel materials and some other influencing factors are ***,this paper classifies the heat transfer enhancement technology and reviews the related studies on both the single-phase and phase-change flow and heat *** comprehensive review is expected to provide a theoretical reference and technical guidance for further research and application of MCHSs in the future.

关键词： microchannel heat sink thermal management of electronics microscale heat transfer heat transfer enhancement