The giant jellyfish Nemopilema nomurai is the largest and most dangerous jellyfish species in East Asian waters,and the N.nomurai bloom causes serious problem in coastal industries,fisheries,and tourism.In the previou...The giant jellyfish Nemopilema nomurai is the largest and most dangerous jellyfish species in East Asian waters,and the N.nomurai bloom causes serious problem in coastal industries,fisheries,and tourism.In the previous surveys,we found N.nomurai could not be observed in the south of 30°N.In this paper,we analyzed the mechanism of this phenomenon.After exploring the possible impacts of different environmental factors,we found that physical processes are essential to the distribution pattern of N.nomurai rather than biological or chemical factors in the East China Sea.The combination of the location of the initial breeding places of N.nomurai and the current system determine the distribution pattern.This study could provide important insights to the potential control of the giant jellyfish in the Chinese coastal waters.展开更多
A room temperature physical model was used to study the bubble behavior and gas induced bath circulation in a drained aluminum reduction cell. By passing compressed argon through the penetrated Plexiglas box bottom pl...A room temperature physical model was used to study the bubble behavior and gas induced bath circulation in a drained aluminum reduction cell. By passing compressed argon through the penetrated Plexiglas box bottom plate immersed in water, gas evolution at the anode bottom surface was simulated. Bubble behavior and liquid flow field were studied and analysis was presented. Bath secondary recirculation was observed in the interpolar gap not the net rising flow as expected. Liquid driven by the bubbles forms small vortices along the interpolar gap with small mean and turbulent velocities and accordingly poor mass transfer. Secondary recirculation also exists between the slot and interpolar gap, part of the flow in the interpolar gap go to the slot with the bubbles and fluid at the bottom of the slot enters the interpolar gap directly without going to the center channel. The existence of the fluid secondary recirculation is very unfavorable to the alumina dissolution and dispersion. Increasing the anode tilt or gas flow rate, or decreasing the anode-cathode distance can make the secondary recirculation in the interpolar gap weak, however, will intensify the secondary recirculation between the slot and interpolar gap.展开更多
We present two approaches to system identification, i.e. the identification of partial differentialequations (PDEs) from measurement data. The first is a regression-based variational systemidentification procedure tha...We present two approaches to system identification, i.e. the identification of partial differentialequations (PDEs) from measurement data. The first is a regression-based variational systemidentification procedure that is advantageous in not requiring repeated forward model solves andhas good scalability to large number of differential operators. However it has strict data typerequirements needing the ability to directly represent the operators through the available data.The second is a Bayesian inference framework highly valuable for providing uncertaintyquantification, and flexible for accommodating sparse and noisy data that may also be indirectquantities of interest. However, it also requires repeated forward solutions of the PDE modelswhich is expensive and hinders scalability. We provide illustrations of results on a model problemfor pattern formation dynamics, and discuss merits of the presented methods.展开更多
It is shown that the well-known wave behaviors of material particles and photons, as well as the newly discovered wave-like structures in the cosmic redshift, are related phenomena that follow conclusively when sender...It is shown that the well-known wave behaviors of material particles and photons, as well as the newly discovered wave-like structures in the cosmic redshift, are related phenomena that follow conclusively when senders and receivers of photons or material particles are topologically located in manifolds with a dimension difference of one. In this context, the inertial mass of the proton and the electron, their spin properties and the cause of time are derived from basic topological and physical laws. In addition, the quantum geometric basis of relativistic time dilation, the basis of the relativistic energy-momentum relationship and the relationship between energy and time are shown. Finally, it is shown that a curved cosmic space causes a distance-dependent reddening of light and the associated apparent escape velocity of distant cosmic objects, and that this also leads to a topologically conditioned wave structure of this redshift.展开更多
The present study has evaluated the effect of architectural forms on the walking activity of citizens as a behavioral model in urban physical spaces.The research hypothesis claims that by designing purposeful and appr...The present study has evaluated the effect of architectural forms on the walking activity of citizens as a behavioral model in urban physical spaces.The research hypothesis claims that by designing purposeful and appropriate architectural forms,the behavior and actions of users in urban physical spaces can be to some extent,it designed or controlled,and that the pattern and domains of human behavior in urban streets are the result of the components of environmental quality that are included in the design of that street.The present theoretical proposition has been tested in two sequences from Valiasr Street in Tehran.At the theoretical level,the research method is descriptive-analytical and at the experimental level,it is a survey that has been done using the behavioral research method.The results show that the floor form and street form are the most influential architectural forms in urban physical spaces on the activity of users walking from space in the study sample.Also,some environmental factors have a direct effect on human reactions;The research findings show that people’s speed is directly related to the dimensions of sidewalk carpets and a person tries to take a step according to the senses he receives from the sidewalk flooring form and as a result his speed changes according to those forms.展开更多
A two-dimensional finite element method (FEM) model that incorporates faults,elastic rock physical properties,topographical load due to gravity and far-field plate velocity boundary conditions was used to recognize th...A two-dimensional finite element method (FEM) model that incorporates faults,elastic rock physical properties,topographical load due to gravity and far-field plate velocity boundary conditions was used to recognize the seismogenic stress state along the fold-and-thrust belt of the Precordillera-Sierras Pampeanas ranges of western Argentina. A plane strain model with nine experiments was presented here to examine the fault strength with two major rock phyical properties:cohesion and angle of internal friction. Mohr-Coulomb failure criterion with bulk rock properties were applied to analyse faults. The stress field at any point of the model was assumed to be comprised of gravitational and tectonic components. The analysis was focused to recognize the seismogenic shear strain concentrated in the internal-cristaline domain of the orogene shown by the modeling. Modeling results are presented in terms of four parameters,i. e.,(i) distributions,orientations,and magnitudes of principal stresses (σ1 and σ3),(ii) displacement vector,(iii) strain distribution,and (iv) maximum shear stress (τmax) contour line within the model. The simulation results show that the compressive stress is distributed in and around the fault systems. The overall orientation of σ1 is in horizontal directions,although some stress reorientations do occur within weaker parts,especially subsequent to the faults. A large-scale shear stress is accumulating along the active faults of Tapias-Villicum Fault (TVF),Salinas-Berros Fault (SBF),Ampacama-Niquizanga Fault (ANF) and Las Charas Fault (CF),which could act as local stress and strain modulators to localize the earthquakes occurrence.展开更多
基金Supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Nos.XDA19060204,XDA23050502)the State Key Program of National Natural Science of China(No.42130411)+4 种基金the Key Deployment Project of Centre for Ocean Mega-Research of ScienceChinese Academy of Sciences(CAS)(No.COMS2019J03)the International Science Partnership Program of the Chinese Academy of Sciences(Nos.121311KYSB20190029,133137KYSB20200002)the Laoshan Laboratory(No.LSKJ202204005)the Aoshan Science and Technology Innovation Program(No.2016ASKJ02-4)。
文摘The giant jellyfish Nemopilema nomurai is the largest and most dangerous jellyfish species in East Asian waters,and the N.nomurai bloom causes serious problem in coastal industries,fisheries,and tourism.In the previous surveys,we found N.nomurai could not be observed in the south of 30°N.In this paper,we analyzed the mechanism of this phenomenon.After exploring the possible impacts of different environmental factors,we found that physical processes are essential to the distribution pattern of N.nomurai rather than biological or chemical factors in the East China Sea.The combination of the location of the initial breeding places of N.nomurai and the current system determine the distribution pattern.This study could provide important insights to the potential control of the giant jellyfish in the Chinese coastal waters.
文摘A room temperature physical model was used to study the bubble behavior and gas induced bath circulation in a drained aluminum reduction cell. By passing compressed argon through the penetrated Plexiglas box bottom plate immersed in water, gas evolution at the anode bottom surface was simulated. Bubble behavior and liquid flow field were studied and analysis was presented. Bath secondary recirculation was observed in the interpolar gap not the net rising flow as expected. Liquid driven by the bubbles forms small vortices along the interpolar gap with small mean and turbulent velocities and accordingly poor mass transfer. Secondary recirculation also exists between the slot and interpolar gap, part of the flow in the interpolar gap go to the slot with the bubbles and fluid at the bottom of the slot enters the interpolar gap directly without going to the center channel. The existence of the fluid secondary recirculation is very unfavorable to the alumina dissolution and dispersion. Increasing the anode tilt or gas flow rate, or decreasing the anode-cathode distance can make the secondary recirculation in the interpolar gap weak, however, will intensify the secondary recirculation between the slot and interpolar gap.
基金We acknowledge the support of Defense Advanced Research Projects Agency(Grant HR00111990S2)Toyota Research Institute(Award#849910).
文摘We present two approaches to system identification, i.e. the identification of partial differentialequations (PDEs) from measurement data. The first is a regression-based variational systemidentification procedure that is advantageous in not requiring repeated forward model solves andhas good scalability to large number of differential operators. However it has strict data typerequirements needing the ability to directly represent the operators through the available data.The second is a Bayesian inference framework highly valuable for providing uncertaintyquantification, and flexible for accommodating sparse and noisy data that may also be indirectquantities of interest. However, it also requires repeated forward solutions of the PDE modelswhich is expensive and hinders scalability. We provide illustrations of results on a model problemfor pattern formation dynamics, and discuss merits of the presented methods.
文摘It is shown that the well-known wave behaviors of material particles and photons, as well as the newly discovered wave-like structures in the cosmic redshift, are related phenomena that follow conclusively when senders and receivers of photons or material particles are topologically located in manifolds with a dimension difference of one. In this context, the inertial mass of the proton and the electron, their spin properties and the cause of time are derived from basic topological and physical laws. In addition, the quantum geometric basis of relativistic time dilation, the basis of the relativistic energy-momentum relationship and the relationship between energy and time are shown. Finally, it is shown that a curved cosmic space causes a distance-dependent reddening of light and the associated apparent escape velocity of distant cosmic objects, and that this also leads to a topologically conditioned wave structure of this redshift.
文摘The present study has evaluated the effect of architectural forms on the walking activity of citizens as a behavioral model in urban physical spaces.The research hypothesis claims that by designing purposeful and appropriate architectural forms,the behavior and actions of users in urban physical spaces can be to some extent,it designed or controlled,and that the pattern and domains of human behavior in urban streets are the result of the components of environmental quality that are included in the design of that street.The present theoretical proposition has been tested in two sequences from Valiasr Street in Tehran.At the theoretical level,the research method is descriptive-analytical and at the experimental level,it is a survey that has been done using the behavioral research method.The results show that the floor form and street form are the most influential architectural forms in urban physical spaces on the activity of users walking from space in the study sample.Also,some environmental factors have a direct effect on human reactions;The research findings show that people’s speed is directly related to the dimensions of sidewalk carpets and a person tries to take a step according to the senses he receives from the sidewalk flooring form and as a result his speed changes according to those forms.
基金the Ministry of Education, Culture, Sports, Science and Technology (Monbukagakusho) of Japan for its financial support of this research.
文摘A two-dimensional finite element method (FEM) model that incorporates faults,elastic rock physical properties,topographical load due to gravity and far-field plate velocity boundary conditions was used to recognize the seismogenic stress state along the fold-and-thrust belt of the Precordillera-Sierras Pampeanas ranges of western Argentina. A plane strain model with nine experiments was presented here to examine the fault strength with two major rock phyical properties:cohesion and angle of internal friction. Mohr-Coulomb failure criterion with bulk rock properties were applied to analyse faults. The stress field at any point of the model was assumed to be comprised of gravitational and tectonic components. The analysis was focused to recognize the seismogenic shear strain concentrated in the internal-cristaline domain of the orogene shown by the modeling. Modeling results are presented in terms of four parameters,i. e.,(i) distributions,orientations,and magnitudes of principal stresses (σ1 and σ3),(ii) displacement vector,(iii) strain distribution,and (iv) maximum shear stress (τmax) contour line within the model. The simulation results show that the compressive stress is distributed in and around the fault systems. The overall orientation of σ1 is in horizontal directions,although some stress reorientations do occur within weaker parts,especially subsequent to the faults. A large-scale shear stress is accumulating along the active faults of Tapias-Villicum Fault (TVF),Salinas-Berros Fault (SBF),Ampacama-Niquizanga Fault (ANF) and Las Charas Fault (CF),which could act as local stress and strain modulators to localize the earthquakes occurrence.
