Diffusion of tracer particles in active bath has attracted extensive attention in recent years.So far,most studies have considered isotropic spherical tracer particles,while the diffusion of anisotropic particles has ...Diffusion of tracer particles in active bath has attracted extensive attention in recent years.So far,most studies have considered isotropic spherical tracer particles,while the diffusion of anisotropic particles has rarely been involved.Here we investigate the diffusion dynamics of a rigid rod tracer in a bath of active particles by using Langevin dynamics simulations in a two-dimensional space.Particular attention is paid to how the translation(rotation)diffusion coefficient D_(T)(D_(R))change with the length of rod L and active strength Fa.In all cases,we find that rod exhibits superdiffusion behavior in a short time scale and returns to normal diffusion in the long time limit.Both D_(T) and D_(R) increase with Fa,but interestingly,a nonmonotonic dependence of D_(T)(D_(R))on the rod length has been observed.We have also studied the translation-rotation coupling of rod,and interestingly,a negative translation-rotation coupling is observed,indicating that rod diffuses more slowly in the parallel direction compared to that in the perpendicular direction,a counterintuitive phenomenon that would not exist in an equilibrium counterpart system.Moreover,this anomalous(diffusion)behavior is reentrant with the increase of Fa,suggesting two competitive roles played by the active feature of bath particles.展开更多
Carbon emissions and water use are two major kinds of human activities. To reveal whether these two activities can modify the hydrological cycle and climate system in China, we conducted two sets of numerical experime...Carbon emissions and water use are two major kinds of human activities. To reveal whether these two activities can modify the hydrological cycle and climate system in China, we conducted two sets of numerical experiments using regional climate model RegCM4. In the first experiment used to study the climatic responses to human carbon emissions, the model were configured over entire China because the impacts of carbon emissions can be detected across the whole country. Results from the first experiment revealed that near-surface air temperature may significantly increase from 2007 to 2059 at a rate exceeding 0.1 ~C per decade in most areas across the country; southwestern and southeastern China also showed increasing trends in summer precipitation, with rates exceeding 10 mm per decade over the same period. In summer, only northern China showed an increasing trend of evapotranspiration, with increase rates ranging from 1 to 5 mm per decade; in winter, increase rates ranging from 1 to 5 mm per decade were observed in most regions. These effects are believed to be caused by global warming from human carbon emissions. In the second experiment used to study the effects of human water use, the model were configured over a limited region-- Haihe River Basin in the northern China, because compared with the human carbon emissions, the effects of human water use are much more local and regional, and the Haihe River Basin is the most typical region in China that suffers from both intensive human groundwater exploitation and surface water diversion. We incorporated a scheme of human water regulation into RegCM4 and conducted the second experiment. Model outputs showed that the groundwater table severely declined by -10 m in 1971-2000 through human groundwater over- exploitation in the basin; in fact, current conditions are so extreme that even reducing the pumping rate by half cannot eliminate the ground- water depletion cones observed in the area. Other hydrological and climatic elements, such as soil moisture, runoff generation, air humidity, precipitation, wind field, and soil and air temperature, were also significantly affected by anthropogenic water withdrawal and consumption, although these effects could be mitigated by reducing the amount of water drawn for extraction and application.展开更多
There is a good correlation between anomalous Schumann resonance and seismic activities. Pre-earthquake anomalous Schumann resonance is an important manifestation of LAIC (Lithosphere-Atmosphere-Ionosphere Coupling), ...There is a good correlation between anomalous Schumann resonance and seismic activities. Pre-earthquake anomalous Schumann resonance is an important manifestation of LAIC (Lithosphere-Atmosphere-Ionosphere Coupling), which is probably associated with seismic ionospheric disturbance. The observation system parameters of the Yunnan Schumann resonance monitoring stations and the results of statistical and seismic cases analysis are introduced in this paper. Three days before the March 10, 2011 MS5.8 Yingjiang earthquake, anomalous Schumann resonance in the By component (E-W) was observed by Yongsheng station, and two days before the Lincang MS4.0 earthquake of January 23, 2011, anomalous Schumann resonance in the By component was detected by the same station. Spectrum analysis results on the By component observations of Tonghai station show that strong disturbances were observed in spectral density corresponding to the first three Schumann resonant frequencies on the very day of the MS4.2 Honghe earthquake of May 22, 2011. Research shows that Schumann resonance monitoring is a feasible method for seismic-electromagnetic precursors monitoring.展开更多
Hydrothermal fuid containing abundant matter erupts from seafloor, meets ambient cold seawater and forms chimneys. So the main matter origins of chimneys are seawater and matter which are taken by hydrothermal fluid f...Hydrothermal fuid containing abundant matter erupts from seafloor, meets ambient cold seawater and forms chimneys. So the main matter origins of chimneys are seawater and matter which are taken by hydrothermal fluid from deep reservoir. However, because of seawater＇s little contribution to the forming of chimneys, it is usually covered by the abundant matter which is taken by hydrothermal fluid. Therefore, chimneys formed in ordinary deep elements, cannot be used to study the seawater＇s seawater hydrothermal activity, containing complex contribution to their formation. While the native sulfur chimneys, formed by hydrothermal activity near the sea area off Kueishantao, are single sulfur composition （over 99%）, and within chimneys distinct layers are seen. Different layers were sampled for trace element determination, with Inductively Coupled Plasma Mass Spectrometry （ICP-MS）. By analyzing the data, we consider C-layer （secondary inner-layer） as the framework layer of the chimney which formed early （Fig.4）, and its trace elements derive from hydrothermal fluid. While the trace elements within A, B, D layers have undergone later alteration. A, B layers are affected by seawater and D layer by hydrothermal fluid. The increase of trace elements of A and B layers was calculated using C layer as background. Based on the known typical volume of chimneys of the near sea area off Kueishantao, we calculated the volume of seawater that contributed trace element to chimneys formation to be about 6.37×10^4 L. This simple quantified estimate may help us better understand the seafloor hydrothermal activity and chimneys.展开更多
Chemical synaptic couplings are more common than electric(gap junction) connections in neurons.In this paper,the firing synchronizations induced by chemical synaptic coupling in chemically delayed scale-free networks ...Chemical synaptic couplings are more common than electric(gap junction) connections in neurons.In this paper,the firing synchronizations induced by chemical synaptic coupling in chemically delayed scale-free networks of modified Hodgkin-Huxley neurons have been studied.It was found that the chemical coupling-induced synchronization transitions are delay-dependent and much different for various delay lengths.In the absence of delay,the neurons exhibit a transition from chaotic bursting(CB) to bursting synchronization(BS) with desynchronized spikes in each burst;for smaller delay lengths,the firing evolves from CB to spiking synchronization(SS),but for larger delay lengths,there are transitions from CB to intermittently multiple SS behaviors.These findings show that the chemical coupling-induced firing synchronization transitions strongly depend on the chemical delay lengths,and intermittently multiple SS can only occur for larger delay lengths.This result would be helpful for better understanding the joint roles of the chemical coupling and chemical delay in the firing activity of the neurons.展开更多
Thallium(Tl) is a typical toxic heavy metal,with higher toxicity to mammals than Hg,Cd,and Pb.Accurate assessments of its environmental exposure and flux are central to effective management and control of Tl pollution...Thallium(Tl) is a typical toxic heavy metal,with higher toxicity to mammals than Hg,Cd,and Pb.Accurate assessments of its environmental exposure and flux are central to effective management and control of Tl pollution.This paper first presents in detail the environmental exposure and flux of Tl by typical industrial activities utilizing Tl-bearing pyrite minerals to produce sulfuric acid.For this purpose,sequential extraction and Inductively Coupled Plasma Mass Spectrometry(ICP-MS) were used to investigate total content and geo-chemical partitioning of Tl in raw pyrite ores and solid roasting wastes,thereby uncovering Tl distribution and transformation during the production process.Results showed that some portions of Tl bearing in the minerals went into vapor,which transferred Tl into different processes;and some portions of Tl went into water during the gas washing procedure,leaving some other portions remained in the solid slags.More importantly,detailed investigation revealed that 40% of Tl in the pyrite minerals was active,among which 25% of Tl originally in the pyrite minerals was washed into water during gas cleaning process and 15% of active Tl retained in the slags.The latter portion of active Tl could be possibly transferred to the soil or water with the slag deposal or being reused;and 60% of Tl remained relatively stable in the residual phase.展开更多
基金supported by the Ministry of Science and Technology of China(2016YFA0400904 and 2018YFA0208702)the National Natural Science Foundation of China(No.21973085,No.21833007,No.21790350,No.21673212,No.21521001 and No.21473165)+1 种基金the Fundamental Research Funds for the Central Universities(WK2340000074)Anhui Initiative in Quantum Information Technologies(AHY090200)。
文摘Diffusion of tracer particles in active bath has attracted extensive attention in recent years.So far,most studies have considered isotropic spherical tracer particles,while the diffusion of anisotropic particles has rarely been involved.Here we investigate the diffusion dynamics of a rigid rod tracer in a bath of active particles by using Langevin dynamics simulations in a two-dimensional space.Particular attention is paid to how the translation(rotation)diffusion coefficient D_(T)(D_(R))change with the length of rod L and active strength Fa.In all cases,we find that rod exhibits superdiffusion behavior in a short time scale and returns to normal diffusion in the long time limit.Both D_(T) and D_(R) increase with Fa,but interestingly,a nonmonotonic dependence of D_(T)(D_(R))on the rod length has been observed.We have also studied the translation-rotation coupling of rod,and interestingly,a negative translation-rotation coupling is observed,indicating that rod diffuses more slowly in the parallel direction compared to that in the perpendicular direction,a counterintuitive phenomenon that would not exist in an equilibrium counterpart system.Moreover,this anomalous(diffusion)behavior is reentrant with the increase of Fa,suggesting two competitive roles played by the active feature of bath particles.
文摘Carbon emissions and water use are two major kinds of human activities. To reveal whether these two activities can modify the hydrological cycle and climate system in China, we conducted two sets of numerical experiments using regional climate model RegCM4. In the first experiment used to study the climatic responses to human carbon emissions, the model were configured over entire China because the impacts of carbon emissions can be detected across the whole country. Results from the first experiment revealed that near-surface air temperature may significantly increase from 2007 to 2059 at a rate exceeding 0.1 ~C per decade in most areas across the country; southwestern and southeastern China also showed increasing trends in summer precipitation, with rates exceeding 10 mm per decade over the same period. In summer, only northern China showed an increasing trend of evapotranspiration, with increase rates ranging from 1 to 5 mm per decade; in winter, increase rates ranging from 1 to 5 mm per decade were observed in most regions. These effects are believed to be caused by global warming from human carbon emissions. In the second experiment used to study the effects of human water use, the model were configured over a limited region-- Haihe River Basin in the northern China, because compared with the human carbon emissions, the effects of human water use are much more local and regional, and the Haihe River Basin is the most typical region in China that suffers from both intensive human groundwater exploitation and surface water diversion. We incorporated a scheme of human water regulation into RegCM4 and conducted the second experiment. Model outputs showed that the groundwater table severely declined by -10 m in 1971-2000 through human groundwater over- exploitation in the basin; in fact, current conditions are so extreme that even reducing the pumping rate by half cannot eliminate the ground- water depletion cones observed in the area. Other hydrological and climatic elements, such as soil moisture, runoff generation, air humidity, precipitation, wind field, and soil and air temperature, were also significantly affected by anthropogenic water withdrawal and consumption, although these effects could be mitigated by reducing the amount of water drawn for extraction and application.
基金sponsored by the"Research on Earthquake and the Schumann Resonance Anomaly"(2010IES0202)sponsored by the"Geophysical Site Dynamic Magic and Strong Earthquake Precast Test"(2010008007)
文摘There is a good correlation between anomalous Schumann resonance and seismic activities. Pre-earthquake anomalous Schumann resonance is an important manifestation of LAIC (Lithosphere-Atmosphere-Ionosphere Coupling), which is probably associated with seismic ionospheric disturbance. The observation system parameters of the Yunnan Schumann resonance monitoring stations and the results of statistical and seismic cases analysis are introduced in this paper. Three days before the March 10, 2011 MS5.8 Yingjiang earthquake, anomalous Schumann resonance in the By component (E-W) was observed by Yongsheng station, and two days before the Lincang MS4.0 earthquake of January 23, 2011, anomalous Schumann resonance in the By component was detected by the same station. Spectrum analysis results on the By component observations of Tonghai station show that strong disturbances were observed in spectral density corresponding to the first three Schumann resonant frequencies on the very day of the MS4.2 Honghe earthquake of May 22, 2011. Research shows that Schumann resonance monitoring is a feasible method for seismic-electromagnetic precursors monitoring.
基金Supported by the Pilot Project of Knowledge Innovation Project, Chinese Academy of Sciences (No.KZCX2-YW-211and KZCX3-SW- 223)the National Natural Science Foundation of China (No. 40830849)the Special Foundation for the Eleventh Five-Year Plan of COMRA (No. DYXM-115-02-1-03).
文摘Hydrothermal fuid containing abundant matter erupts from seafloor, meets ambient cold seawater and forms chimneys. So the main matter origins of chimneys are seawater and matter which are taken by hydrothermal fluid from deep reservoir. However, because of seawater＇s little contribution to the forming of chimneys, it is usually covered by the abundant matter which is taken by hydrothermal fluid. Therefore, chimneys formed in ordinary deep elements, cannot be used to study the seawater＇s seawater hydrothermal activity, containing complex contribution to their formation. While the native sulfur chimneys, formed by hydrothermal activity near the sea area off Kueishantao, are single sulfur composition （over 99%）, and within chimneys distinct layers are seen. Different layers were sampled for trace element determination, with Inductively Coupled Plasma Mass Spectrometry （ICP-MS）. By analyzing the data, we consider C-layer （secondary inner-layer） as the framework layer of the chimney which formed early （Fig.4）, and its trace elements derive from hydrothermal fluid. While the trace elements within A, B, D layers have undergone later alteration. A, B layers are affected by seawater and D layer by hydrothermal fluid. The increase of trace elements of A and B layers was calculated using C layer as background. Based on the known typical volume of chimneys of the near sea area off Kueishantao, we calculated the volume of seawater that contributed trace element to chimneys formation to be about 6.37×10^4 L. This simple quantified estimate may help us better understand the seafloor hydrothermal activity and chimneys.
基金supported by the Natural Science Foundation of Shandong Province of China (ZR2009AM016)
文摘Chemical synaptic couplings are more common than electric(gap junction) connections in neurons.In this paper,the firing synchronizations induced by chemical synaptic coupling in chemically delayed scale-free networks of modified Hodgkin-Huxley neurons have been studied.It was found that the chemical coupling-induced synchronization transitions are delay-dependent and much different for various delay lengths.In the absence of delay,the neurons exhibit a transition from chaotic bursting(CB) to bursting synchronization(BS) with desynchronized spikes in each burst;for smaller delay lengths,the firing evolves from CB to spiking synchronization(SS),but for larger delay lengths,there are transitions from CB to intermittently multiple SS behaviors.These findings show that the chemical coupling-induced firing synchronization transitions strongly depend on the chemical delay lengths,and intermittently multiple SS can only occur for larger delay lengths.This result would be helpful for better understanding the joint roles of the chemical coupling and chemical delay in the firing activity of the neurons.
基金supported by the United Sponsorship of the National Natural Science Foundation of China and the Guangdong Provincial Government(Grant No.U0633001)the National Natural Science Foundation of China(Grant No.20477007)the Guangdong Provincial Sponsorship for Key Science and Technology(Grant No.2004A3038002)
文摘Thallium(Tl) is a typical toxic heavy metal,with higher toxicity to mammals than Hg,Cd,and Pb.Accurate assessments of its environmental exposure and flux are central to effective management and control of Tl pollution.This paper first presents in detail the environmental exposure and flux of Tl by typical industrial activities utilizing Tl-bearing pyrite minerals to produce sulfuric acid.For this purpose,sequential extraction and Inductively Coupled Plasma Mass Spectrometry(ICP-MS) were used to investigate total content and geo-chemical partitioning of Tl in raw pyrite ores and solid roasting wastes,thereby uncovering Tl distribution and transformation during the production process.Results showed that some portions of Tl bearing in the minerals went into vapor,which transferred Tl into different processes;and some portions of Tl went into water during the gas washing procedure,leaving some other portions remained in the solid slags.More importantly,detailed investigation revealed that 40% of Tl in the pyrite minerals was active,among which 25% of Tl originally in the pyrite minerals was washed into water during gas cleaning process and 15% of active Tl retained in the slags.The latter portion of active Tl could be possibly transferred to the soil or water with the slag deposal or being reused;and 60% of Tl remained relatively stable in the residual phase.
