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Research on the knee region of cosmic ray by using a novel type of electron-neutron detector array

Frontiers of physics 2024年第4期19卷 13-24页

作者： Bing-Bing Li Xin-Hua Ma Shu-Wang Cui hao-kun chen Tian-Lu chen Danzengluobu Wei Gao Hai-Bing Hu Denis Kuleshov Kirill Kurinov Hu Liu Mao-Yuan Liu Ye Liu Da-Yu Peng Yao-Hui Qi Oleg Shchegolev Yuri Stenkin Li-Qiao Yin Heng-Yu Zhang Liang-Wei Zhang College of Physics Hebei Normal UniversityShijiazhuang 050024China Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China TIANFU Cosmic Ray Research Center Chengdu 610000China College of Science Tibet UniversityLhasa 850000China Key Laboratory of Comic Rays Ministry of EducationTibet UniversityLhasa 850000China Institute for Nuclear Research of the Russian Academy of Sciences Moscow 117312Russia School of Physical Science and Technology Southwest Jiaotong UniversityChengdu 610031China School of Management Science and Engineering Hebei University of Economics and BusinessShijiazhuang 050061China Moscow Institute of Physics and Technology Moscow 141700Russia

By accurately measuring composition and energy spectrum of cosmic ray,the origin problem of so called“knee”region(energy>one PeV)can be ***,up to the present,the results of the spectrum in the knee region obtained by several previous experiments have shown obvious differences,so they cannot give effective evidence for judging the theoretical models on the origin of the ***,the Large High Altitude Air Shower Observatory(LHAASO)has reported several major breakthroughs and important results in astro-particle physics *** on its advantages of wide-sky survey,high altitude location and large area detector arrays,the research content of LHAASO experiment mainly includes ultra high-energy gamma-ray astronomy,measurement of cosmic ray spectra in the knee region,searching for dark matter and new phenomena of particle physics at higher *** electron and thermal neutron detector(EN-Detector)is a new scintillator detector which applies thermal neutron detection technology to measure cosmic ray extensive air shower(EAS).This technology is an extension of *** EN-Detector Array(ENDA)can highly efficiently measure thermal neutrons generated by secondary hadrons so called“skeleton”of *** this paper,we perform the optimization of ENDA configuration,and obtain expectations on the ENDA results,including thermal neutron distribution,trigger efficiency and capability of cosmic ray composition *** obtained real data results are consistent with those by the Monte Carlo simulation.

关键词： cosmic ray EAS knee region LHAASO ENDA

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Numerical and experimental investigation into the evolution of the shock wave when a muzzle jet impacts a constrained moving body

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Defence Technology（防务技术） 2024年第3期33卷 317-326页

作者： Zijie Li hao Wang Changshun chen kun Jiang School of Energy and Power Engineering Nanjing University of Science and TechnologyNanjing 210016China

The gun-track launch system is a new special launch device that connects the track outside the *** it is constrained by the track,the characteristics of development of the muzzle jet differ from those of the traditional muzzle ***,it changes from freely developing to doing so in a constrained manner,where this results in an asymmetric direction of flow as well as spatio-temporal coupling-induced interference between various shock waves and the formation of *** this background,the authors of this article formulate and consider the development and characteristics of evolution of the muzzle jet as it impacts a constrained moving *** designed simulations to test the gun-track launch system,and established a numerical model based on the dynamic grid method to explore the development and characteristics of propagation of disturbances when the muzzle jet impacted a constrained moving *** also considered models without a constrained track for the sake of *** results showed that the muzzle jet assumed a circumferential asymmetric shape,and tended to develop in the area above the *** the test platform was close to the ground,the muzzle jet was subjected to reflections from it that enhanced the development and evolution of various forms of shock waves and vortices in the muzzle jet to exacerbate its rate of distortion and asymmetric *** in turn led to significant differences in the changes in pressure at symmetric points that would otherwise have been *** results of a comparative analysis showed that the constrained track could hinder the influence of reflections from the ground on the muzzle jet to some extent,and could reduce the velocity of the shock waves inducing the motion of the muzzle as well as the Mach number of the moving *** work here provides a theoretical basis and the requisite technical support for applications of the gun-track launch *** also sheds light on the

关键词： Shock wave/vortex interference Muzzle jet Constrained boundary Dynamic grid

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Effect of Reclamation on the Groundwater-Lake Water Interaction in chen Lake

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Journal of Earth Science 2024年第3期35卷 1083-1086页

作者： kun Lei Teng Ma Liuzhu chen Zhenxing Li Yu chen School of Environmental Studies State Key Laboratory of Biogeology and Environmental GeologyChina University of GeosciencesWuhan 430078China

0 INTRODUCTION To relieve the short supply of suitable land for residing,cultivating,and commerce,it is accepted to reclaim land from lakes,river estuaries,and coastal regions in many countries(Mancini et al.,2020).The large-scale reclamation activities have an irreversible effect on the mico-geomorphology and hydrodynamic system of seasonally flooded areas(Zhang et al.,2019;Yu et al.,2018).For example,coastal regions reclaimed extended the groundwater flow paths,as well as created groundwater level rise,resulting in water-logging in the reclaimed area(Hu et al.,2008).Similar changes in groundwater flow systems may alter groundwater-lake water interactions,and it can ultimately affect the water cycle in the lake ***,such detailed studies are presently *** addition,natural exchanges between the lake and groundwater systems can be strongly affected by physical hydrological processes(Javadzadeh et al.,2020),chemical properties(Kamtchueng et al.,2015),and bioto behavior(Hancock et al.,2005).

关键词： groundwater coastal logging

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Precise control of page cache for containers

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Frontiers of Computer Science 2024年第2期18卷 17-30页

作者： kun WANG Song WU Shengbang LI Zhuo HUANG hao FAN chen YU Hai JIN National Engineering Research Center for Big Data Technology and System Services Computing Technology and System LabCluster and Grid Computing Lab School of Computer Science and TechnologyHuazhong University of Science and TechnologyWuhan 430074China

Container-based virtualization isbecoming increasingly popular in cloud computing due to its efficiency and *** isolation is a fundamental property of *** works have indicated weak resource isolation could cause significant performance degradation for containerized applications and enhanced resource ***,current studies have almost not discussed the isolation problems of page cache which is a key resource for *** leverage memory cgroup to control page cache ***,existing policy introduces two major problems in a container-based ***,containers can utilize more memory than limited by their cgroup,effectively breaking memory ***,the Os kernel has to evict page cache to make space for newly-arrived memory requests,slowing down containerized *** paper performs an empirical study of these problems and demonstrates the performance impacts on containerized *** we propose pCache(precise control of page cache)to address the problems by dividing page cache into private and shared and controlling both kinds of page cache separately and *** do so,pCache leverages two new technologies:fair account(f-account)and evict on demand(EoD).F-account splits the shared page cache charging based on per-container share to prevent containers from using memory for free,enhancing memory *** EoD reduces unnecessary page cache evictions to avoid the performance *** evaluation results demonstrate that our system can effectively enhance memory isolation for containers and achieve substantial performance improvement over the original page cache management policy.

关键词： page cache memory cgroup container isolation cloud computing

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A review of reservoir damage during hydraulic fracturing of deep and ultra-deep reservoirs

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Petroleum Science 2024年第1期21卷 384-409页

作者： kun Zhang Xiong-Fei Liu Dao-Bing Wang Bo Zheng Tun-hao chen Qing Wang hao Bai Er-Dong Yao Fu-Jian Zhou National Key Laboratory of Petroleum Resources and Engineering China University of Petroleum-BeijingBeijing102249China School of Mechanical Engineering Beijing Institute of Petrochemical TechnologyBeijing102617China Tuha Downhole Operation Company CNPC Xibu Drilling Engineering Company LimitedShanshan838200XinjiangChina

Deep and ultra-deep reservoirs have gradually become the primary focus of hydrocarbon exploration as a result of a series of significant discoveries in deep hydrocarbon exploration *** reservoirs present unique challenges due to their deep burial depth(4500-8882 m),low matrix permeability,complex crustal stress conditions,high temperature and pressure(HTHP,150-200℃,105-155 MPa),coupled with high salinity of formation ***,the costs associated with their exploitation and development are exceptionally *** deep and ultra-deep reservoirs,hydraulic fracturing is commonly used to achieve high and stable *** hydraulic fracturing,a substantial volume of fluid is injected into the ***,statistical analysis reveals that the flowback rate is typically less than 30%,leaving the majority of the fluid trapped within the ***,hydraulic fracturing in deep reservoirs not only enhances the reservoir permeability by creating artificial fractures but also damages reservoirs due to the fracturing fluids *** challenging“three-high”environment of a deep reservoir,characterized by high temperature,high pressure,and high salinity,exacerbates conventional forms of damage,including water sensitivity,retention of fracturing fluids,rock creep,and proppant *** addition,specific damage mechanisms come into play,such as fracturing fluid decomposition at elevated temperatures and proppant diagenetic reactions at HTHP ***,the foremost concern in deep oil and gas development lies in effectively assessing the damage inflicted on these reservoirs by hydraulic fracturing,comprehending the underlying mechanisms,and selecting appropriate ***'s noteworthy that the majority of existing studies on reservoir damage primarily focus on conventional reservoirs,with limited attention given to deep reservoirs and a lack of systematic *** light of this,our approach entails initially summarizin

关键词： Artificial fracture Deep and ultra-deep reservoir Fracture conductivity Fracturing fluid Hydraulic fracturing Reservoir damage

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A froth velocity measurement method based on improved U-Net++semantic segmentation in flotation process

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International Journal of Minerals,Metallurgy and Materials 2024年第8期31卷 1816-1827页

作者： Yiwei chen Degang Xu kun Wan School of Automation Central South UniversityChangsha 410083China

During flotation,the features of the froth image are highly correlated with the concentrate grade and the corresponding working *** static features such as color and size of the bubbles and the dynamic features such as velocity have obvious differences between different working *** extraction of these features is typically relied on the outcomes of image segmentation at the froth edge,making the segmentation of froth image the basis for studying its visual ***,the absence of scientifically reliable training data with label and the necessity to manually construct dataset and label make the study difficult in the mineral *** solve this problem,this paper constructs a tungsten concentrate froth image dataset,and proposes a data augmentation network based on Conditional Generative Adversarial Nets(cGAN)and a U-Net++-based edge segmentation *** performance of this algorithm is also evaluated and contrasted with other algorithms in this *** the results of semantic segmentation,a phase-correlationbased velocity extraction method is finally suggested.

关键词： froth flotation froth segmentation froth image data augmentation velocity extraction image features

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Efficient removal of U(VI) from wastewater by a sponge-like 3D porous architecture with hybrid electrospun nanofibers

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Water Science and Engineering 2024年第2期17卷 150-156页

作者： Lin Hu Lin chen Xian-kun Wu Rui Luo Rong-guan Lv Zheng-hao Fei Feng Yang School of Chemistry and Environmental Engineering Yancheng Teachers UniversityYancheng 224051China Jiangsu Province Engineering Research Center of Agriculural Breeding Pollution Control and Resource Yancheng 224051China Jiangsu Nanda Huaxing Science and Technology of Environmental Protection Co.Ltd. Yancheng 224001China

Removal of uranium(VI)from nuclear wastewater is urgent due to the global nuclear energy *** study synthesized novel sponge-like 3D porous materials for enhanced uranium adsorption by combining electrospinning and fibrous freeze-shaping *** materials possessed an organic-inorganic hybrid architecture based on the electrospun fibers of polyacrylonitrile(PAN)and SiO_(2).As a sup-porting material,the surface of fibrous SiO_(2) could be further functionalized by cyano groups via(3-cyanopropyl)*** the cyano groups were turned into amidoxime(AO)groups to obtain a amidoxime-functionalized sponge(PAO/SiO_(2)-AO)through the subsequent ami-doximation *** proposed sponge exhibited enhanced uranium adsorption performance with a high removal capacity of 367.12 mg/g,a large adsorption coefficient of 4.0×10^(4)mL/g,and a high removal efficiency of 97.59%.The UO_(2)^(2+)adsorption kinetics perfectly conformed to the pseudo-second-order *** sorbent also exhibited an excellent selectivity for UO_(2)^(2+) with other interfering metal ions.2023 Hohai *** and hosting by Elsevier B.V.

关键词： Uranium removal Sponge Amidoximation Organic-inorganic hybrid structure Electrospinning

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Research progresses and prospects of multi-sphere compound extremes from the Earth System perspective

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Science China Earth Sciences 2024年第2期67卷 343-374页

作者： Zengchao hao Yang chen College of Water Sciences Beijing Normal UniversityBeijing100875China State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing100081China

Compound extremes,whose socioeconomic and ecological impacts are severer than that caused by each event occurring in isolation,have evolved into a hot topic in Earth Science in the past *** the context of climate change,many compound extremes have exhibited increasing frequency and intensity,and shown novel fashions of combinations,posing more pressing demands and tougher challenges to scientific research and disaster prevention and *** article,via a perspective of multi-sphere interactions within the Earth System,systematically reviews the status quo,new scientific understanding,and deficiencies regarding the definition,mechanism,change,attribution,and projection of compound *** study also sorts out existing challenges and outlines a potential roadmap in advancing the study on compound extremes with respect to data requirement,mechanistic diagnosis,numerical modeling,attribution and projection,risk assessment,and adaptive *** directions of compound extremes studies and key research topics that warrant multi-disciplinary and multisectoral coordinated efforts are also *** that climate change has reshaped the type of extremes,a transformation from the traditional single-event perspective to a compound-event perspective is needed for scientific research,disaster prevention and mitigation,and climate change adaptation,calling for bottom-up innovation in research objects,ideas,and *** article will add value to promoting the research on compound extremes and interdisciplinary cooperations.

关键词： Extremes Compound extremes Climate change and risk Multi-sphere interactions

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Sub-nanosized vanadate hybrid clusters maintain glucose homeostasis and restore treatment response in inflammatory disease in obese mice

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Nano Research 2024年第3期17卷 1818-1826页

作者： kun chen Shengqiu Liu Yujun Wei South China Advanced Institute for Soft Matter Science and Technology School of Emergent Soft MatterSouth China University of TechnologyGuangzhou 510641China Guangdong Provincial Key Laboratory of Technique and Equipment for Macromolecular Advanced Manufacturing South China University of TechnologyGuangzhou 510641China Guangdong Provincial Key Laboratory of Functional and Intelligent Hybrid Materials and Devices South China University of TechnologyGuangzhou 510641China

Obesity is closely related with insulin resistance and chronic ***,we report that unsaturated lipid-modified polyoxovanadates(ULPOVs)can restrict weight gain of diet-induced obese mice and improve their glycemic control and obesity-associated *** administration of the sub-nanosized ULPOVs at a low dosage for 7 weeks reduces the body weight and almost normalizes the blood glucose levels of obese mice fed on a high-fat *** treatment increases the activity of the nuclear receptor peroxisome proliferator-activated receptorγ(PPARγ)and reduces intestinal caloric intake,which may be the main reason for blood sugar and body weight *** addition to insulin-sensitizing,PPARγactivation induced by ULPOV treatment in obese mice with atopic dermatitis(AD)promotes the type 2 T helper(TH_(2))cell selective responses and therapeutic effects on immune dysregulation caused by *** data suggest sub-nanosized polyoxovanadate clusters as a class of potential candidates to relieve symptoms accompanied by diet-induced obesity.

关键词： polyoxovanadates lipid modification glucose homeostasis obesity inflammatory disease peroxisome proliferator-activated receptorγ(PPARγ)

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Generalized Inverses and Units in a Unitary Ring

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Acta Mathematica Sinica,English Series 2024年第4期40卷 1000-1014页

作者： Yu kun ZHOU Jian Long chen School of Mathematics Southeast UniversityNanjing 210096P.R.China

Let R be a unitary ring and a,b∈R with ab=*** find the 2/3 property of Drazin invertibility:if any two of a,b and a+b are Drazin invertible,then so is the third ***,we combine the 2/3 property of Drazin invertibility to characterize the existence of generalized inverses by means of *** applications,the need for two invertible morphisms used by You and chen to characterize the group invertibility of a sum of morphisms is reduced to that for one invertible morphism,and the existence and expression of the inverse along a product of two regular elements are obtained,which generalizes the main result of Mary and Patricio(2016)about the group inverse of a product.

关键词： Leftπ-regular element stronglyπ-regular element group inverse Drazin inverse inverse along an element

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