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MONTE CARLO STUDY ON THE CRITICAL ADSORPTION POINT OF BONDFLUCTUATED POLYMER CHAINS TETHERED ON ADSORBING SURFACES
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作者 陆文琴 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2009年第1期109-114,共6页
The behavior of three-dimensional bond fluctuation model chains tethered on an adsorbing fiat surface was simulated by the Monte Carlo method.The dependence of the number of surface contacts M on the interaction stren... The behavior of three-dimensional bond fluctuation model chains tethered on an adsorbing fiat surface was simulated by the Monte Carlo method.The dependence of the number of surface contacts M on the interaction strengthεand the chain length N was investigated by a finite-size scaling law M = N;[a;+a;N;κ+ O((N;κ);)]forεnear the critical adsorption pointε;,i.e.,κ=(ε-ε;)/ε;closes to 0.The critical adsorption point was estimated to beε;=0.93,and the exponentsφ= 0.49 and l/v= 0.57. 展开更多
关键词 Critical adsorption Polymer chain Bond fluctuation model SCALING Monte Carlo
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Fluctuated lattice-driven charge density wave far above the condensation temperature in kagome superconductor KV3Sb5
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作者 Haoran Liu Shaofeng Duan +9 位作者 Xiangqi Liu Zhihua Liu Shichong Wang Lingxiao Gu Jiongyu Huang Wenxuan Yang Jianzhe Liu Dong Qian Yanfeng Guo Wentao Zhang 《Science Bulletin》 2025年第8期1211-1214,共4页
The kagome lattice,characterized by its network of cornersharing triangles,provides an excellent platform for studying various novel quantum phenomena.The recently discovered kagome metal AV3Sb5(A=K,Rb,Cs)[1]garners s... The kagome lattice,characterized by its network of cornersharing triangles,provides an excellent platform for studying various novel quantum phenomena.The recently discovered kagome metal AV3Sb5(A=K,Rb,Cs)[1]garners significant attention for its unique properties,including an unconventional charge density wave(CDW)and superconductivity(SC)[2],as well as the interplay between CDW and SC[3]. 展开更多
关键词 fluctuated lattice driven charge density wave studying various novel quantum phenomenathe charge density wave cdw cornersharing triangles kagome latticecharacterized kv sb kagome metal kagome superconductor
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The association between daily temperature extremes and human biomarkers:heterogeneous effects of occupation and season
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作者 Yang Zhao Chunmei Yang +3 位作者 Yina Li Haiou Hong Rui Wang Jiuchang Wei 《中国科学技术大学学报》 北大核心 2025年第3期53-66,52,I0002,共16页
The impact of extreme temperatures on the health of individuals in different organizations remains uncertain.We employed stratified analyses to examine the impacts of summer(April-September)daily maximum temperatures ... The impact of extreme temperatures on the health of individuals in different organizations remains uncertain.We employed stratified analyses to examine the impacts of summer(April-September)daily maximum temperatures and winter(October-March)daily minimum temperatures on blood pressure and lipid profiles across government staff,com-pany employees,and researchers.We examined 209,477 physical examination records from a physical examination center in the First Affiliated Hospital of USTC from 2017 to 2021.Employing a segmented regression model within the frame-work of generalized linear regression(GLM),we examined the causal impact of extreme temperatures on health outcomes.Additionally,sensitivity analyses were conducted via distributed lag nonlinear models(DLNMs),with a focus on ob-serving the long-term effects over a period of 21 days.Our findings indicate that government staff face increased health risks during extremely low temperatures,regardless of the season.Compared with participants experiencing median tem-peratures,government staff exposed to extremely low temperatures(below the 10th percentile,below 24℃)in the sum-mer presented maximum increases of 2.32 mmHg(95%CI:1.542-3.098)in diastolic blood pressure and 6.481 mmHg(95%CI:5.368-7.594)in systolic blood pressure.In winter,government staff exposed to temperatures below the 10th per-centile(below 1℃)demonstrated maximum increases of 0.278 mmol/L(95%CI:0.210-0.346)in total cholesterol,0.153 mmol/L(95%CI:0.032-0.274)in triglycerides,and 0.077 mmol/L(95%CI:0.192-0.134)in low-density lipoprotein.Conversely,warm winters benefit company employees,whereas researchers exhibit lower sensitivity to temperature changes in winter.The maximum temperatures in summer and minimum temperatures in winter had greater impacts on in-dividuals.Small temperature fluctuations impact health more than large changes do.Notably,both the maximum and min-imum temperatures were better predictors of health outcomes than the daily average temperature was.Blood pressure con-sistently displayed significant associations with temperature across all three groups,with extremely low temperatures in-creasing the risk and extremely high temperatures reducing it.However,the relationship between temperature and blood lipids is complex. 展开更多
关键词 extreme temperature stress response organizational members temperature fluctuation SUBTROPICAL
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Voxel-based alterations in spontaneous brain activity among verylate-onset schizophrenia-like psychosis:A preliminary resting-state functional magnetic resonance imaging study
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作者 Dan-Ting Yang Ping Ji +4 位作者 Jiao-Jiao Sun Yan-Sha Gan Shuai-Yi Guo Zhen-He Zhou Xue-Zheng Gao 《World Journal of Psychiatry》 2025年第3期66-77,共12页
BACKGROUND Very late-onset schizophrenia-like psychosis(VLOSLP)is a subtype of schizophrenia spectrum disorders in which individuals experience psychotic symptoms for the first time after the age of 60.The incidence o... BACKGROUND Very late-onset schizophrenia-like psychosis(VLOSLP)is a subtype of schizophrenia spectrum disorders in which individuals experience psychotic symptoms for the first time after the age of 60.The incidence of VLOSLP shows a linear relationship with increasing age.However,no studies have reported alterations in spontaneous brain activity among VLOSLP patients and their correlation with cognitive function and clinical symptoms.AIM To explore VLOSLP brain activity and correlations with cognitive function and clinical symptoms using resting-state functional magnetic resonance imaging.METHODS This study included 33 VLOSLP patients and 34 healthy controls.The cognitive assessment utilized the Mini Mental State Examination,Montreal Cognitive Assessment,and the Repeatable Battery for the Assessment of Neuropsychological Status(RBANS).Clinical characteristic acquisition was performed via the Positive and Negative Syndrome Scale(PANSS).All participants were scanned via resting-state functional magnetic resonance imaging,and the data were processed using amplitude of low-frequency fluctuations(ALFF),fractional ALFF(fALFF),regional homogeneity,and voxelmirrored homotopic connectivity(VMHC).RESULTS The VLOSLP group presented decreased ALFF values in the left cuneus,right precuneus,right precentral gyrus,and left paracentral lobule;increased fALFF values in the left caudate nucleus;decreased fALFF values in the right calcarine fissure and surrounding cortex(CAL)and right precuneus;increased regional homogeneity values in the right putamen;and decreased VMHC values in the bilateral CAL,bilateral superior temporal gyrus,and bilateral cuneus.In the VLOSLP group,ALFF values in the right precuneus were negatively correlated with Mini Mental State Examination score and PANSS positive subscale score,and VMHC values in the bilateral CAL were negatively correlated with the RBANS total score,RBANS delayed memory score,and PANSS positive subscale score.CONCLUSION The changes of brain activity in VLOSLP are concentrated in the right precuneus and bilateral CAL regions,which may be associated with cognitive impairment and clinically positive symptoms. 展开更多
关键词 Very-late-onset schizophrenia-like psychosis SCHIZOPHRENIA Resting-state functional magnetic resonance imaging Amplitude of low-frequency fluctuations Fractional amplitude of low-frequency fluctuations Regional homogeneity Voxelmirrored homotopic connectivity
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Rapid and specific fluorescent probe visualizes dynamic correlation of Cys and HClO in OGD/R
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作者 Pei Huang Weijie Zhang +2 位作者 Junping Wang Fangjun Huo Caixia Yin 《Chinese Chemical Letters》 2025年第1期437-441,共5页
Intracellular redox homeostasis is of indispensable importance in pathophysiology.In order to maintain the balance of the redox state within the cell,reactive oxygen species(ROS)and reactive sulfur species(RSS)react a... Intracellular redox homeostasis is of indispensable importance in pathophysiology.In order to maintain the balance of the redox state within the cell,reactive oxygen species(ROS)and reactive sulfur species(RSS)react and transform with each other,and their levels also directly reflect the degree of oxidative stress and disease.Hypochlorous acid(HClO)and cysteine(Cys)usually co-exist in organisms,interacting with each other in many important physiological processes and synergistically maintaining the dynamic redox balance in the body.To understand the relevance and pathophysiological effects of these two signaling molecules in oxidative stress,unique fluorescence imaging tools are required.Herein,we designed and developed a dual-channel fluorescent probe HP,for the individual and continuous detection of HClO and Cys.This probe could simultaneously monitor the changes in the concentrations of HClO and Cys in cells,and was characterized by a fast response,high sensitivity and high selectivity,especially compared with glutathione(GSH)and homocysteine(Hcy),the probe had a good specificity for Cys.Importantly,probe HP successfully observed dynamic changes in HCl O-and Cys-mediated redox status in the oxygenglucose deprivation/reperfusion(OGD/R)model of HeLa cells and dynamically monitored fluctuations in endogenous HClO levels in lipopolysaccharides(LPS)-induced peritonitis mice. 展开更多
关键词 Redox homeostasis DUAL-CHANNEL OGD/R FLUCTUATIONS PERITONITIS
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Effects of doors on an open cavity flow at Mach number 6
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作者 Baoping NIE Xilin HU Zhufei LI 《Chinese Journal of Aeronautics》 2025年第2期75-91,共17页
Open cavities with different door-opening angles are investigated using high-speed schlieren visualization and dynamic pressure measurements in hypersonic flow with a freestream Mach number of 6.With the help of numer... Open cavities with different door-opening angles are investigated using high-speed schlieren visualization and dynamic pressure measurements in hypersonic flow with a freestream Mach number of 6.With the help of numerical simulations,the shear layer deformation and pressure increase in the cavities due to the impingement of the door-leading-edge shocks are identified via comparison with those in the cavity without doors.As the door-opening angle decreases from 90°,the shear layer above the forepart of the cavity is gradually raised by the high pressure in the cavity.When the door-opening angle decreases to 30°and 15°,the boundary layer on the upstream flat plate of the cavity separates,and separation shock is observed.The doors enhance the instability of the cavity flow and increase the pressure fluctuations in the cavities.A new oscillation pattern,referred to as coupled oscillation,is observed in the cases with separation on the upstream flat plate,in which the separation shock oscillates at the same dominant frequency as the flow inside the cavity.Compared with the cavity without doors,this coupled oscillation causes a lower oscillation frequency and a larger overall sound pressure level.Cross-correlation analyses between pressure signals indicate that the disturbances generated at the trailing edge of the cavity can propagate to the separation on the upstream flat plate and cause coupled oscillation of the separation shock.The fundamental frequencies of the coupled oscillations can be normalized to approximately the same Strouhal number as that of the cavity without doors.These findings support that the oscillation mechanisms of hypersonic cavities without and with doors are primarily dominated by acoustic feedback. 展开更多
关键词 Hypersonic flow Cavity oscillation Doors Shear-layer deformation Pressure fluctuation Acoustic feedback
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Non-stationary response of complex ecosystem service networks to urbanization:Evidence from a typical eco-fragile area in China
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作者 Zhen Shen Yang Gao +3 位作者 Lei Wang Zheyi Xia Haowei Liu Ting Deng 《Geography and Sustainability》 2025年第1期170-184,共15页
Understanding the complex interactions between urbanization and ecosystem services(ESs)is crucial for optimiz ing planning policies and achieving sustainable urban management.While previous research has largely focuse... Understanding the complex interactions between urbanization and ecosystem services(ESs)is crucial for optimiz ing planning policies and achieving sustainable urban management.While previous research has largely focused on highly urbanized areas,little attention has been given to the phased effect of progressive urbanization on ES networks.This study proposes a conceptual framework that utilizes the network method and space-time replace ment to examine the effect of urbanization on the complex relationships among ESs at different stages,with a particular emphasis on the progressive evolution of the process.We apply this framework to the Horqin area,a typical eco-fragile area in China.Results demonstrate that the connectivity of the ES synergy network exhibits a non-stationary characteristic,initially increasing,then decreasing,and subsequently strengthening.Meanwhile,its modularity shows a rising trend during periods of accelerated urbanization.The performance of the trade off network displays the opposite pattern.Additionally,we observe a gradual replacement of provisioning and regulation services by cultural services in terms of dominance in the synergy network as urbanization advances.By providing guidance for identifying key planning initiatives and implementing ecological protection policies at different stages of development,this study contributes a pathway that can inform development strategies in other regions undergoing progressive urbanization. 展开更多
关键词 Ecosystem services URBANIZATION Network analysis Non-stationary fluctuation
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Airborne Investigation of Riming:Cloud and Precipitation Microphysics within a Weak Convective System in North China
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作者 Xiangfeng HU Hao HUANG +9 位作者 Shaoyu HOU Kun ZHAO Chuanfeng ZHAO Yinghui LU Jiefang YANG Rong ZHANG Delong ZHAO Weiguo LIU Dan ZHANG Haixia XIAO 《Advances in Atmospheric Sciences》 2025年第3期515-526,共12页
The process of riming significantly impacts the microphysical characteristics of clouds.This study uses aircraft and radar observation data in stratiform clouds with convection embedded that occurred in the central an... The process of riming significantly impacts the microphysical characteristics of clouds.This study uses aircraft and radar observation data in stratiform clouds with convection embedded that occurred in the central and southern regions of North China on 22 May 2017.The microphysical structural characteristics and processes near the embedded convection core and in the stratiform cloud are analyzed comparatively.Particular attention is given to the effect of riming on the microphysical properties near the upper boundary of the melting layer and to the factors influencing riming efficiency.The collaborative observations reveal that the particle size distributions observed near the convection core and in the stratiform region are close,while the particle properties like habit and riming degree are quite different.Above the melting layer,larger plate-like ice particles and supercooled water droplets(D>50μm)are more abundant near the convective core,leading to higher collision efficiencies between ice particles and supercooled water droplets.Larger fluctuation amplitudes of vertical airflow near the convective core also contribute to the increased riming activity and the formation of more heavily rimed particles,such as graupel.Furthermore,in situ measurements from airborne probes also revealed that above the melting layer,the riming process involves two stages:the mass of snow crystals grows as supercooled droplets merge internally without changing size,followed by external freezing that significantly enlarges the crystals. 展开更多
关键词 RIMING collision efficiency airflow fluctuation particle habit aircraft measurement
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Seasonal effects on groundwater fluoride and evaluating health hazards: In-situ remediation via managed aquifer recharge
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作者 D.Karunanidhi Meera Rajan +1 位作者 Priyadarsi D.Roy T.Subramani 《Geoscience Frontiers》 2025年第5期123-138,共16页
This research examines the hard-rock aquifer system within the Nagavathi River Basin(NRB)South India,by evaluating seasonal fluctuations in groundwater composition during the pre-monsoon(PRM)and post-monsoon(POM)perio... This research examines the hard-rock aquifer system within the Nagavathi River Basin(NRB)South India,by evaluating seasonal fluctuations in groundwater composition during the pre-monsoon(PRM)and post-monsoon(POM)periods.Seasonal variations significantly influence the groundwater quality,particularly fluoride(F−)concentrations,which can fluctuate due to changes in recharge,evaporation,and anthropogenic activities.This study assesses the dynamics of F−levels in PRM and POM seasons,and identifies elevated health risks using USEPA guidelines and Monte Carlo Simulations(MCS).Groundwater in the study area exhibits alkaline pH,with NaCl and Ca-Na-HCO_(3) facies increasing in the POM season due to intensified ion exchange and rock-water interactions,as indicated in Piper and Gibb’s diagrams.Correlation and dendrogram analyses indicate that F−contamination is from geogenic and anthropogenic sources.F−levels exceed the WHO limit(1.5 mg/L)in 51 PRM and 28 POM samples,affecting 371.74 km^(2) and 203.05 km^(2),respectively.Geochemical processes,including mineral weathering,cation exchange,evaporation,and dilution,are identified through CAI I&II.Health risk assessments reveal that HQ values>1 in 78%of children,73%of teens,and 68%of adults during PRM,decreasing to 45%,40%,and 38%,respectively,in POM.MCS show maximum HQ values of 5.67(PRM)and 4.73(POM)in children,with all age groups facing significant risks from fluoride ingestion.Managed Aquifer Recharge(MAR)is recommended in this study to minimize F−contamination,ensuring safe drinking water for the community. 展开更多
关键词 FLUORIDE Seasonal fluctuations Geochemical processes Geogenic sources Managed aquifer recharge
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A Dark Energy Hypothesis IV
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作者 James Togeas 《Journal of High Energy Physics, Gravitation and Cosmology》 2025年第1期45-55,共11页
The subject is the thermodynamics of dark matter, the Helmholtz free energy. The method of fluctuations leads to an estimate of the mass of a dark matter particle. The picture that emerges is that of a small-mass, deg... The subject is the thermodynamics of dark matter, the Helmholtz free energy. The method of fluctuations leads to an estimate of the mass of a dark matter particle. The picture that emerges is that of a small-mass, degenerate, spinless boson. Contour integration produces dark matter equations of state. 展开更多
关键词 Dark Matter Helmholtz Free Energy FLUCTUATIONS FUGACITY BE Gas and Condensate
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Rift marginal coarse-grained sediment gravity flow deposits in the Eocene Dongying Depression,Bohai Bay Basin,China:Balancing tectonic and climatic controls
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作者 Rong-Heng Tian Ben-Zhong Xian +8 位作者 Peng Chen Lin Zhao Naveed Ur Rahman Muhammad Ubaid Umar Qian-Ran Wu Qian Li Wen-Miao Zhang Jian-Ping Liu Si-Rui Chen 《Petroleum Science》 2025年第8期3168-3188,共21页
Previous studies have indicated that sediment gravity flow deposits developed in lacustrine active extensional rift basins are primarily influenced by tectonics and to a lesser extent by climate.Our present work revea... Previous studies have indicated that sediment gravity flow deposits developed in lacustrine active extensional rift basins are primarily influenced by tectonics and to a lesser extent by climate.Our present work reveals that climate can obscure the effect of tectonic subsidence by regulating sediment supply;conversely,tectonics can impede the sedimentary manifestation of climatic impacts.Here a case study has been presented to assess the impact of climate-modulated rapid lake-level rise and tectonic subsidence on the development of coarse-grained gravity flow deposits in the Dongying rift margin of the Bohai Bay Basin,eastern China.The lithofacies analysis reveals frequent bed amalgamation,abundant thick massive coarse-grained deposits,widespread cross bedding and plant fragments,and incomplete composite bed formed by high-energy erosion,indicating that the hyperpycnal flow is an important mechanism driving the deposition of these coarse-grained sediments.Detailed sequence stratigraphic analysis and sediment dispersal pattern suggest that the long-striped nearshore subaqueous fan systems induced by outburst-flood hyperpycnal flow distributed along the border fault,are primarily controlled by long-term tectonics,while the rapid rise of lake level driven by short-term climate change possibly intensifies seasonal flood-generated hyperpycnal flow occurrences and consequently promotes the basinal fan progradation.The maximum scale of these coarse-grained gravity flow deposits of the basinal fan systems are typically attained during the transgressive systems tract,which deviates from the classical sequence stratigraphic model.Furthermore,it presented a continuous transition from the proximal to the distal part,encompassing traction flows and turbidity currents during the periods of relatively stable tectonics.Nevertheless,gravel-rich debris flows appear to predominate the dispersion of coarse-grained sediments during periods characterized by intense tectonic activity.The coarse-grained gravity flow deposits in the lacustrine rift margin reported here,challenge the traditional beliefs:this study suggests that subaqueous deposits abundantly preserved in the transgressive setting. 展开更多
关键词 Tectonic activity Climatic fluctuation Rift margin Gravity flow deposits
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Mobilization of heavy metals from floodplain sediments of the Yellow River during redox fluctuations
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作者 Fuyu Xie Xiaoqing Li +2 位作者 Qingxiang Yang Ying Meng Fubo Luan 《Journal of Environmental Sciences》 2025年第4期432-439,共8页
The floodplain of the Yellow River is a typical area characterized by redox fluctuations and heavy metal pollution.However,the mobilization behavior of heavy metals in floodplain sediments during redox fluctuations re... The floodplain of the Yellow River is a typical area characterized by redox fluctuations and heavy metal pollution.However,the mobilization behavior of heavy metals in floodplain sediments during redox fluctuations remains poorly understood.In this study,reductive mobilization of Fe and Mn was observed under reducing environments through reduction and dissolution,leading to the subsequent release of adsorbed As.In contrast,the mobilization of U occurred under oxic conditions,as the oxidative state of U(VI)has higher solubility.Furthermore,insignificant effects on the mobilization of Cd,Cu,Pb,and Hg were noticed during redox fluctuations,indicating higher stability of these heavymetals.Additionally,we demonstrated that carbon sources can play a key role in the mobilization of heavy metals in floodplain sediments,amplifying the reductive mobilization of Fe,Mn,As and the oxidative mobilization of U.Our findings contribute to the understanding of the biogeochemical cycling of heavy metal in floodplain sediments of the Yellow River and the factors that control this cycling. 展开更多
关键词 Biogeochemical cycling Redox fluctuation Heavy metal Carbon supplementation The Yellow River
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Method of Bionic Fish Scale Structure on Pressure Fluctuation Suppression of a Centrifugal Pump
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作者 Xingyu Jia Qixuan Sun +2 位作者 Xuechu Zhao Bing Liu Lei Tan 《哈尔滨工程大学学报(英文版)》 2025年第5期1037-1048,共12页
Centrifugal pumps are extensively employed in ocean engineering,such as ship power systems,water transportation,and mineral exploitation.Pressure fluctuation suppression is essential for the operation stability and se... Centrifugal pumps are extensively employed in ocean engineering,such as ship power systems,water transportation,and mineral exploitation.Pressure fluctuation suppression is essential for the operation stability and service life of the centrifugal pump.In this paper,a new method of bionic structure is proposed for the blade surface of a centrifugal pump,which is inspired by the fish scale and comprises a leading edge,a trailing edge,and two symmetrical side edges.This fish scale structure is applied to the blade pressure and suction surfaces,and an impeller with a fish scale structure is constructed.A test rig for a centrifugal pump is developed to determine the pressure fluctuation in the pump with a prototype impeller and fish scale structure impeller.Results reveal that the dominant frequency of pressure fluctuation in volute is the blade passing frequency(f_(bpf))of 193.33 Hz,which is triggered by the interaction between the tongue and the impeller.The bionic structure of the fish scale effectively suppresses the pressure fluctuation amplitude at f_(bpf).From flow rates of 0.6 Q_(d)to 1.2 Q_(d),the average suppressions in pressure fluctuation amplitudes at f_(bpf)are 20.98%,5.85%,19.20%,and 25.77%. 展开更多
关键词 Pressure fluctuation Centrifugal pump Fish scale Bionic structure Blade passing frequency
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Risk Mitigation Effectiveness of Foreign Well-Known Trademark Protection During Supply Chain Fluctuations
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作者 LI Yinge 《Chinese Business Review》 2025年第1期9-20,共12页
The global supply chain turbulence has increased the difficulty of protecting foreign well-known trademarks.Although there are many studies on cross-border trademark rights protection in academia,there is relatively l... The global supply chain turbulence has increased the difficulty of protecting foreign well-known trademarks.Although there are many studies on cross-border trademark rights protection in academia,there is relatively little research on its risk mitigation effectiveness in the context of supply chain fluctuations.Based on case studies of commercial law and data statistics,the study explores the relationship between protection efficiency and market response through legal applicability.Due to the long litigation cycle and uneven law enforcement,there are differences in market regulation,weakening the protection of well-known trademarks and exacerbating supply chain uncertainty.Strengthening international legal framework cooperation and promoting law enforcement linkage can enhance protection effectiveness.In theory,enriching the theory of cross-border trademark protection and expanding research on brand rights protection in the context of global supply chains.In practice,it helps enterprises adjust their trademark layout,avoid legal risks,and improve market competitiveness.Due to the complexity of the legal environment and limitations in data acquisition,future research will strengthen data analysis,promote international cooperation in intelligent supervision,and build a more efficient cross-border well-known trademark protection mechanism. 展开更多
关键词 supply chain resilience famous trademark risk mitigation economic fluctuations intellectual property
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Experimental Study of a Helium Sorption Cooler with Low Temperature Fluctuation and Long Hold Time below 1 K
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作者 Tianshuo Liu Xiaoyu Cui +6 位作者 Lihao Lu Kongkuai Ying Yang Wang Kangjun Liu Zilong Wang Zhenhua Jiang Shaoshuai Liu 《Frontiers in Heat and Mass Transfer》 2025年第3期739-750,共12页
Helium sorption cooler technology is a key means to realize highly reliable low-vibration very lowtemperature environments,which have important applications in fields such as quantum computing and space exploration.Th... Helium sorption cooler technology is a key means to realize highly reliable low-vibration very lowtemperature environments,which have important applications in fields such as quantum computing and space exploration.The laboratory designed a superfluid suppression small hole and a multi-ribbed condenser,developed a reliable-performance helium sorption cooler(HSC),and conducted experimental studies.Experimental results show that the prototype can achieve the lowest cooling temperature of 873 mK without load by filling 6MPa helium at room temperature.The low-temperature hold time is 26 h,and the temperature fluctuation is within 0.8 mK.The cooling power of the helium sorption cooler is 1 mW@0.98 K@3.5 h.Experimental results indicate that when the charging pressure is reduced to 4MPa,theminimum temperature decreases to 836mK,and the hold time shortens to 16 h.When the pre-cooling temperature increases from 3.9 to 4.9 K,the hold time is reduced to 3 h. 展开更多
关键词 Helium sorption cooler low temperature condenser superfluid suppression hold time temperature fluctuation experimental study
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Fluctuating course of attention-deficit/hyperactivity disorder across development:Multifactorial influences
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作者 Xi-Wen Zeng Lan-Fang Hu +2 位作者 Xiao-Lan Cao Bin-Rang Yang Zhao-Min Wu 《World Journal of Psychiatry》 2025年第8期149-160,共12页
Attention-deficit/hyperactivity disorder(ADHD)is increasingly conceptualized as a dynamic neurodevelopmental condition,marked by fluctuating symptom trajectories across development rather than the traditional static p... Attention-deficit/hyperactivity disorder(ADHD)is increasingly conceptualized as a dynamic neurodevelopmental condition,marked by fluctuating symptom trajectories across development rather than the traditional static patterns of persistence or remission.This review synthesizes empirical evidence on the varied trajectories of ADHD symptoms-including late-onset,partial remission,and recurrent fluctuation patterns-and underscores their clinical significance in longterm functioning.We adopt a multifactorial framework to explore how genetic,environmental,and gene–environment interactions contribute to the emergence and evolution of ADHD symptoms over time.In addition,we consider how medication-related variables-particularly tolerance and adherence-may influence symptom fluctuation.Characterizing these developmental dynamics offers critical guidance for designing flexible,personalized interventions that align with individual trajectories and transitional vulnerabilities. 展开更多
关键词 Attention-deficit/hyperactivity disorder Symptom fluctuation Developmental trajectories Longitudinal studies Gene-environment interaction
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Acceptance effect on the N_(t)N_(p)/N_(d)^(2)ratio of light nuclei coalescence yields as a probe of nucleon density fluctuations
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作者 An Gu Michael X.Zhang 《Nuclear Science and Techniques》 2025年第3期157-166,共10页
A coalescence model was employed to form deuterons(d),tritons(t),and helium-3(^(3)He)nuclei from a uniformly-distributed volume of protons(p)and neutrons(n).We studied the ratio N_(t)N_(p)/N_(d)^(2)of light nuclei yie... A coalescence model was employed to form deuterons(d),tritons(t),and helium-3(^(3)He)nuclei from a uniformly-distributed volume of protons(p)and neutrons(n).We studied the ratio N_(t)N_(p)/N_(d)^(2)of light nuclei yields as a function of the neutron density fluctuations.We investigated the effect of finite transverse momentum(p_(T))acceptance on the ratio,in particular,the“extrapolation factor”(f)for the ratio as a function of the p_(T)spectral shape and the magnitude of neutron density fluctuations.The nature of f was found to be monotonic in p_(T)spectra“temperature”parameter and neutron density fluctuation magnitude;variations in the latter are relatively small.We also examined f in realistic simulations using the kinematic distributions of protons measured from the heavy-ion collision data.The nature of f was found to be smooth and monotonic as a function of the beam energy.Therefore,we conclude that extrapolation from limited p_(T)ranges does not create,enhance,or reduce the local peak of the N_(t)N_(p)/N_(d)^(2)ratio in the beam energy.Our study provides a necessary benchmark for light nuclei ratios as a probe for nucleon density fluctuations,an important observation in the search for the critical point of nuclear matter. 展开更多
关键词 Heavy-ion collision Critical point Light nuclei coalescence Nucleon density fluctuations
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Galloping characteristics of catenary positive feeder considering aerodynamic damping
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作者 LI Yanzhe JIN Xianglong +3 位作者 ZHAO Shanpeng ZHANG Youpeng WANG Sihua LI Wanrun 《Journal of Measurement Science and Instrumentation》 2025年第1期142-153,共12页
The purpose of this study is to analyze the galloping characteristics of the catenary positive feeder in fluctuating wind areas considering dynamic-wind angle of attack and aerodynamic damping.Firstly,the flow field m... The purpose of this study is to analyze the galloping characteristics of the catenary positive feeder in fluctuating wind areas considering dynamic-wind angle of attack and aerodynamic damping.Firstly,the flow field model of the catenary positive feeder was established,the fluctuating wind field was simulated by Davenport wind power spectrum and linear filtering method,and the wind speed at inlet in calculation domain was controlled by editing the profile file to simulate and calculate the aerodynamic characteristics of the positive feeder in the fluctuating wind area.Then,taking the positive feeder as the research object,the mathematical model of actual structure and the corresponding finite element model were established.By applying the wind load to the finite element model,the influence of aerodynamic damping caused by the self-movement of the positive feeder on the galloping response was analyzed,and the frequency domain characteristics of galloping displacement of the positive feeder considering aerodynamic damping were studied.Finally,the calculation method of aerodynamic damping by the Guidelines for Electrical Transmission Line Structural Loading(ASCE No.74)was used for the galloping response of the positive feeder and compared with the proposed method.The results show that when considering aerodynamic damping,the galloping amplitude of the positive feeder decreases significantly,and the first-order resonance effect on the vertical displacement and horizontal displacement decreases significantly.The galloping trajectories calculated by the two methods are consistent.Therefore,this study is of great significance to further clarify the ice-free galloping mechanism of the catenary positive feeder in violent wind areas. 展开更多
关键词 positive feeder aerodynamic damping fluctuating wind area galloping characteristics nonlinear dynamic analysis
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Stochastic analysis in gas-solid two-phase flow in the dense-phase pneumatic conveying of pulverized coal
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作者 Yong Jin Weizhong Gu 《Chinese Journal of Chemical Engineering》 2025年第7期26-37,共12页
The complex dense-phase pneumatic conveying of pulverized coal process was studied using an electrical capacitance tomography(ECT) signal that represented the motion characteristics of gas-solid two-phase flow. The fl... The complex dense-phase pneumatic conveying of pulverized coal process was studied using an electrical capacitance tomography(ECT) signal that represented the motion characteristics of gas-solid two-phase flow. The fluctuation characteristics of conveying process signals are inseparable from the flow pattern. The denoised ECT signal and noise signal were obtained by db2 wavelet analysis. It was found that all noise signals were white Gaussian noise. Based on the assumption of the equal probability distribution of pulverized coal concentration, this paper proved that the time series distribution of pulverized coal concentration in the pipeline should obey the normal distribution. Furthermore, through the analysis of the distribution characteristics of the power spectral density function of denoised ECT signals of four flow patterns, they were α-dimensional fractal Brownian motion(fBm) signals, and the parameter α was estimated by the detrended fluctuation analysis. Based on the fBm characteristics of denoised ECT signals and white Gaussian noise, this paper proposed a method for calculating the pulverized coal concentration in the dense-phase pneumatic conveying. In addition to the method of concentration estimation with the significance of engineering guidance, this research can help people to further understand essential characteristics of ECT signals in the dense-phase pneumatic conveying. 展开更多
关键词 Fractal Brownian motion Detrended fluctuation analysis Electrical capacitance tomography Dense-phase pneumatic conveying Noise
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The sign of kurtosis within finite system near the QCD critical point
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作者 Shanjin Wu 《Nuclear Science and Techniques》 2025年第8期222-229,共8页
The sign of higher-order multiplicity fluctuations is a very important parameter for exploring QCD phase transitions.The kurtosis of the net-baryon is typically negative in simulations of the dynamics of the conserved... The sign of higher-order multiplicity fluctuations is a very important parameter for exploring QCD phase transitions.The kurtosis of the net-baryon is typically negative in simulations of the dynamics of the conserved net-baryon density near the QCD critical point.This paper considers the effects of finite size on multiplicity fluctuations with equilibrium critical fluctuations.It is found that the multiplicity fluctuations(or the magnitude of the correlation function D_(ij))are dramatically suppressed with decreasing system size when the size of the system is small compared with the correlation length,which is the so-called acceptance dependence.Consequently,the small correlation function of the small system size results in the magnitude of the negative contribution(~D_(ij)^(4))in the four-point correlation function dominating the positive term(~D_(ij)^(5)),and this finite-size effect induces a dip structure near the QCD critical point. 展开更多
关键词 Relativistic heavy-ion collisions QCD phase transition Multiplicity fluctuations Finite-size effects
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