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Energy Harvesting in the Wake of An Inverted C-Shaped Bluff Body

China Ocean Engineering 2024年第1期38卷 68-80页

作者： WANG jun-lei LI Shen-fang Md.Mahbub ALAM ZHU Hong-jun HU Guo-biao School of Mechanical and Power Engineering Zhengzhou UniversityZhengzhou 450000China Center for Turbulence Control Harbin Institute of Technology(Shenzhen)Shenzhen 518055China State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu 610500China Internet of Things Thrust The Hong Kong University of Science and Technology(Guangzhou)Guangzhou 511400China

This paper proposes a novel wake-induced vibration(WIV)-based energy harvesting system consisting of two bluff *** inverted C-shaped bluff body is stationary installed at the upstream position to generate an interference wake street,and a cylinder bluff body equipped with a transducer is elastically suspended at the downstream position to harness WIV *** hydrodynamics and energy harvesting(EH)performance of the proposed system are investigated via experimental *** reduced velocity(U*)ranging from 2 to 14(the corresponding Reynolds number ranging from 15100 to 106200)is considered in the present *** is found that the wake generated by the inverted C-shaped bluff body significantly affects the EH *** the opening angle(α)of the C-shaped bluff body increases the vibration amplitude of the downstream cylinder,thereby increasing the harvested *** the spacing(L)between two bluff bodies is two times the cylinder diameter(D),the wake-induced vibration(WIV)mode is observed,while the combined WIV and wake galloping(WG)mode occurs whenαis 150°,and L equals 3D or *** average drag coefficient becomes negative when L is 2D,3D,or *** carefully configuring a C-shaped bluff body,the wake generated by it can bring an augmenting effect on the vibration of the downstream EH *** example,the RMS power output of the proposed EH system reaches a maximum of 0.31 W at U*=8 and L=4D,which is 300%greater than that of its traditional ***,after a number of case stud-ies,it is identified that the proposed EH system can achieve the best performance whenαis 150°and L=2D.

关键词： wake-induced vibration vortex-induced vibration galloping energy harvesting bluff body

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Soil conditioning of clay based on interface adhesion mechanism:Microscopic simulation and laboratory experiment

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Underground Space 2024年第5期18卷 239-255页

作者： yong fang Bin Zhuo Ruyue Zhang Yubo Wang Liupan Dou Yuxiang Yao Key Laboratory of Transportation Tunnel Engineering Ministry of EducationSouthwest Jiaotong UniversityChengdu 610031China

Clogging frequently occurs in the cutter head,excavation chamber or screw conveyor when an earth pressure balance(EPB)shield machine is tunneling in soft or silty clay ground with high clay mineral *** this paper,montmorillonite,kaolinite,and illite were selected as research objects,and molecular dynamics simulation and laboratory experiment were *** the microscopic scale,dynamic contact behavior and interfacial mechanical behavior of the interface between clay minerals and water/surfactant solution was simulated and the interfacial adhesion and conditioning mechanism between clay minerals and water/surfactant solution was ***,sodium dodecyl benzene sulfonate surfactant was selected as the main composition of the soil ***,the adhesion stress before and after soil conditioning and the contact angles between clay minerals and water/surfactant solution were tested and analyzed at the macroscopic *** result shows that the contact angle between droplet and clay mineral surface is an important parameter to characterize soil *** simulation rules of the microscopic contact angle are consistent with the experiment ***,the adsorption energy between microscopic substances is dominated by electrostatic force,which can reflect the adhesion stress between macroscopic *** adhesion stress can be effectively decreased by adding the surfactant to the soil conditioner.

关键词： EPB clogging Clay minerals Microscopic simulation Mechanism analysis Laboratory experiment Adhesion stress

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Impact of atmospheric circulations on droughts and drought propagation over China

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Science China Earth Sciences 2024年第8期67卷 2633-2648页

作者： Ziye GU Lei GU Jiabo YIN Wei fang Lihua XIONG jun GUO Ziyue ZENG jun XIA School of Civil and Hydraulic Engineering Huazhong University of Science and TechnologyWuhan 430074China State Key Laboratory of Water Resources Engineering and Management Wuhan 430072China Changjiang River Scientific Research Institute Wuhan 430010China

The GRACE satellite mission provides a new approach for monitoring,tracking,and assessing drought conditions by detecting changes in Earth's gravitational fields and inversing signals of terrestrial water storage *** studies of terrestrial water storage anomalies related droughts paid rare attention to the behind atmospheric physical mechanisms,nor quantified the risk propagation patterns between terrestrial water storage deficits and hydrological or agricultural *** this study,we first extract terrestrial water storage(TWS) droughts,hydrological droughts,and agricultural droughts by using multiple variables including TWS from the GRACE/GRACE-FO satellites,runoff and soil moisture from the ERA5-Land reanalysis *** then identify key atmospheric and oceanic oscillation indices affecting water deficits by employing machine learning *** characterize the joint distributions between drought duration and severity by using the Copula function and quantify the risk propagation of hydrological and agricultural droughts to TWS *** results show that:(1) From 2002 to 2021,there is a significant decrasing trend of TWS in China;the WPIO group atmospheric circulation indices(sea surface temperature index within the Western Pacific and Indian Ocean) contributes the most to ***,the sea surface temperature anomalies within the NINO 3.4 region as well as the Western Pacific Warm Pool area index show significantly positive correlation relationships with TWS in southern China;(2) The northwestern China,the Yangtze River basin,and the downstream of the Pearl River basin are the hotspots of TWS ***,the hotspots of hydrological droughts locate in northwestern China and the hotspots of agricultural droughts locate in South China and eastern Tibetan Plateau;(3) The elastic coefficients of hydrological droughts propagating to TWS droughts are higher than those of agricultural droughts,indicating that the TWS droughts

关键词： GRACE satellites Drought Drought propagation Atmospheric circulation Copula function

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Quantitative evaluation of the contribution of underground space to urban resilience:A case study in China

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Underground Space 2024年第4期17卷 1-24页

作者： Si-Cong Liu fang-Le Peng yong-Kang Qiao Yun-Hao Dong Research Center for Underground Space&Department of Geotechnical Engineering Tongji UniversityShanghai 200092China

Urban underground space(UUS)development has been acknowledged as a positive contribution to urban resilience(UR).Such contribution has been qualitatively addressed in recent years,but only quantitatively discussed in few *** evaluation methods for UR are widely used in China and around the world,but the role of underground space is barely *** paper provides a way to bridge this gap on the city scale.A UR evaluation framework was carefully constructed that covers the basic aspects and elements of *** contributions of UUS to UR were identified and integrated into the UR evaluation framework,and the measurement methods for each indicator related to UUS were determined.A case study of 19 sample cities in China were conducted using the integrated evaluation *** analysis and clustering analysis were further adopted to interpret the evaluation results,mainly with three indicators reflecting the level of UUS development,namely UUS area(m^(2)),UUS density(104 m^(2)/km^(2))and UUS area per capita(m^(2)/person).The results showed a strong correlation between UUS area and *** average proportion of UR provided by UUS in the 19 sample cities was 16.46%,while the maximum figure reached 29.20%.The sample cities were clustered into four categories based on the relationship between the proportion of UR provided by UUS,UUS area,and GDP per capita,where both high and low UUS area tend to provide less proportion of resilience than the medium UUS *** suggestions for UUS utilization were proposed to assist cities in achieving urban resilience.

关键词： Urban underground space(UUS) Urban resilience Resilience evaluation Resilient development

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Metal-soil interface adhesion in clay clogging during shield tunneling:Theoretical model and experimental validation

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Underground Space 2024年第2期15卷 188-202页

作者： yong fang Bin Zhuo Yubo Wang Hu Luo junfeng Sun Yuxiang Yao Key Laboratory of Transportation Tunnel Engineering Ministry of EducationSouthwest Jiaotong UniversityChengdu 610031China

Clogging is a major geohazards risk in mechanized tunnelling through cohesive *** clogging results from the high adhesion between the clay and *** on the water film theory and Reynolds fluid equation,the interfacial adhesion between metal and soil is simplified in this study as viscous hydrodynamic behavior between *** the influence of capillary force and the viscous force of water film at the interface between metal and soil,a theoretical calculation model of interfacial adhesion between metal and soil is *** influence of water film thickness and separation rate on the interfacial adhesion between metal and soil is qualitatively ***,the adhesion stress between the clay and the metal surface was tested with a pullout test and the influence of moisture content,pullout rates and types of clay minerals on the adhesion stress was ***,the calculation model of adhesion force was compared with the experimental *** calculation model of soil adhesion stress established in this paper can quantitatively describe the relationship between soil adhesion force and moisture content and can also qualitatively reveal the influence mechanism of soil moisture content on adhesion stress.

关键词： EPB clogging Adhesion stress Mechanics model Clays Mechanism analysis Experimental test

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Experimental and numerical study of hypervelocity impact damage on composite overwrapped pressure vessels

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Defence Technology（防务技术） 2024年第1期31卷 58-72页

作者： yong-Pan Duan Run-Qiang Chi Bao-jun Pang Yuan Cai Hypervelocity Impact Research Center Harbin Institute of TechnologyHarbin150080China College of Science Heilongjiang University of Science and TechnologyHarbin 150022China

Ground-based tests are important for studying hypervelocity impact(HVI)damage to spacecraft pressure vessels in the orbital debris *** analyzed the damage to composite overwrapped pressure vessels(COPVs)in the HVI tests and classified the damage into non-catastrophic damage and catastrophic *** proposed a numerical simulation method to further study non-catastrophic damage and revealed the characteristics and mechanisms of non-catastrophic damage affected by impact conditions and internal *** fragments of the catastrophically damaged COPVs were collected after the *** crack distribution and propagation process of the catastrophic ruptures of the COPVs were *** findings contribute to understanding the damage characteristics and mechanisms of COPVs by HVIs.

关键词： Orbital debris Hypervelocity impact Composite overwrapped pressure vessels Damage mechanisms

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Mechanical properties and microstructure of Mg-treated and Catreated industrial H13 steel after quenching and tempering

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Journal of Iron and Steel Research International 2024年第8期31卷 1987-2001页

作者： jun-ying Yue Dong Hou De-yong Wang Tian-peng Qu Xiang-long Li jun Tian School of Iron and Steel Soochow UniversitySuzhou 215021JiangsuChina

The effect of magnesium treatment and calcium treatment on the microstructure and mechanical properties of industrial H13 steel after quenching and tempering was *** impact toughness and tensile tests were mainly carried out,and the microstructure was observed by scanning electron microscopy,electron backscattered diffraction,and X-ray *** results show that magnesium treatment is still feasible in industrial *** is mainly manifested in the refinement of lath martensite and *** with calcium treatment,the prior austenite grains and carbides size of industrial H13 steel treated with magnesium decreased by 3.17μm after *** quenching and tempering,the carbides(especially V-rich carbides)in Mg treatment obviously spheroidized and distributed uniformly and increased in quantity *** lath martensite size is reduced from 2.45 to 2.31μ*** suggests that magnesium treatment was able to yield smaller grains and more evenly distributed ***,the impact toughness,yield strength,and ultimate tensile strength of industrial H13 steel with magnesium treatment increased by 28%,65.5 MPa and 123.7 MPa,*** increment of strength mainly comes from dislocation strengthening,grain refinement strengthening,and precipitation strengthening,among which precipitation strengthening accounts for the largest proportion.

关键词： Industrial H13 steel Mg treatment Heat treatment Carbide-Mechanical property

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Entropy variances of pure coherent states in the diffusion channel

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Chinese Physics B 2024年第9期33卷 384-388页

作者： Wei-Feng Wu yong fang Peng Fu School of Mechanical and Electrical Engineering Chizhou UniversityChizhou 247000China Anhui Research Center of Semiconductor Industry Generic Technology Chizhou 247000China

Using the operator correspondence of the real and fictious modes in the thermo entangled state representation, wesolve the quantum master equation describing the diffusion channel and obtain the Kraus operator-sum representation ofits analytical solution. we find that the pure coherent states evolve into the new mixed thermal superposed states in thediffusion channel. Also, we investigate the statistical properties of the initial coherent states and their entropy evolutions inthe diffusion channel, and find that the entropy evolutions are only related to the decay time and without the amplitudes ofthe initial coherent states.

关键词： entangled state representation diffusion channel coherent state entropy evolution

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Cuproptosis mediates copper-induced testicular spermatogenic cell death

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Asian Journal of Andrology 2024年第3期26卷 295-301页

作者： Jing-Yi Zhang Xu-jun Yu jun-jun Li Yao Xiao Guang-Sen Li fang Yang Liang Dong Chengdu University of Traditional Chinese Medicine Chengdu 611137China Chengdu Fifth People’s Hospital The Fifth People’s Hospital of Chengdu University of Traditional Chinese MedicineChengdu 611130China TCM Regulating Metabolic Diseases Key Laboratory of Sichuan Province Hospital of Chengdu University of Traditional Chinese MedicineChengdu 610072China Department of Surgery The Reproductive and Women-Children HospitalChengdu University of Traditional Chinese MedicineChengdu 610041China

Cuproptosis,a novel mechanism of programmed cell death,has not been fully explored in the context of spermatogenic *** investigated the potential involvement of cuproptosis in spermatogenic cell death using a mouse model of copper *** male Institute of Cancer Research(ICR)mice were randomly divided into four groups that received daily oral gavage withsodium chloride(control)or copper sulfate(CuSO_(4))at 50 mg kg^(−1),100 mg kg^(−1),or 200 mg kg^(−1),for 42 consecutive *** to copper overload exhibited a disruption in copper ***,significant upregulated expression of keycuproptosis factors was accompanied by a significant rise in the rates of testicular tissue cell *** revealed the presence of ferredoxin 1(Fdx1)in Sertoli cells,Leydig cells,and spermatogenic cells at various stages oftesticular development,and the Fdx1-positive staining area was significantly increased in copper-overloaded *** and decreased adenosine triphosphate levels were also observed,further implicating mitochondrial damage *** analyses revealed pathological lesions and blood−testis barrier destruction in the testicular tissue,accompaniedby decreased sperm concentration and motility,in copper-overloaded *** summary,our results indicate that copper-overloadedmice exhibit copper homeostasis disorder in the testicular tissue and that cuproptosis participates in spermatogenic cell *** findings provide novel insights into the pathogenic mechanisms underlying spermatogenic cell death and provide initialexperimental evidence for the occurrence of cuproptosis in the testis.

关键词： blood−testis barrier cuproptosis ferredoxin 1 spermatogenic cell death

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Supermassive Primordial Black Holes for Nano-Hertz Gravitational Waves and High-redshift JWST Galaxies

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Research in Astronomy and Astrophysics 2024年第9期24卷 1-6页

作者： Hai-Long Huang yong Cai jun-Qian Jiang jun Zhang Yun-Song Piao School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China Institute for Astrophysics School of PhysicsZhengzhou UniversityZhengzhou 450001China International Centre for Theoretical Physics Asia-Pacific University of Chinese Academy of SciencesBeijing 100190China Taiji Laboratory for Gravitational Wave Universe(Beijing/Hangzhou) University of Chinese Academy of SciencesBeijing 100049China School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUCASHangzhou 310024China Institute of Theoretical Physics Chinese Academy of SciencesBeijing 100190China

Recently,observational hints for supermassive black holes have been accumulating,prompting the question:Can primordial black holes(PBHs)be supermassive,particularly with masses M■10^(9)M_(⊙)?A supercritical bubble,containing an inflating baby universe,that nucleated during inflation can evolve into a PBH in our observable *** find that when the inflaton slowly transitions past a neighboring vacuum,the nucleation rate of supercritical bubbles inevitably peaks,leading to a mass distribution of multiverse PBHs with a peak mass up to M■10^(11)M_(⊙).Thus,our mechanism naturally provides a primordial origin for supermassive black holes.

关键词： (cosmology:)early universe (cosmology:)inflation (galaxies:)quasars:supermassive black holes

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