1.ObjectivesLaboratory for Surface Physics ofAcademia Sinica(LSPAS)was establishedin 1987 for enhancing the research activity insurface sciences,according to the NationalLaboratory Project of the State PlanningCommitt...1.ObjectivesLaboratory for Surface Physics ofAcademia Sinica(LSPAS)was establishedin 1987 for enhancing the research activity insurface sciences,according to the NationalLaboratory Project of the State PlanningCommittee.During the last 30 years,we have wit-nessed a tremendous development in surfacephysics.Photoemission spectroscopy(1981Nobel prize to Siegbahn for ESCA)offers展开更多
Based on the existing Land Surface Physical Process Models(Deardorff, Dickinson, LIU, Noilhan, Seller, ZHAO), a Comprehensive Land Surface Physical Process Model (CLSPPM) is developed by considering the different phys...Based on the existing Land Surface Physical Process Models(Deardorff, Dickinson, LIU, Noilhan, Seller, ZHAO), a Comprehensive Land Surface Physical Process Model (CLSPPM) is developed by considering the different physical processes of the earth's surface-vegetation-atmosphere system more completely. Compared with SiB and BATS, which are famous for their detailed parameterizations of physical variables, this simplified model is more convenient and saves much more computation time. Though simple, the feas...展开更多
The principal assumptions about equivalence and energy distribution of the asdorption sites on solidsurfaces used by Langmuir for deriving the equation of monomolecular adsorption are generalized and anew physical ads...The principal assumptions about equivalence and energy distribution of the asdorption sites on solidsurfaces used by Langmuir for deriving the equation of monomolecular adsorption are generalized and anew physical adsorption model is proposed and tested with experimental data published in literature.Themodels of Langmuir,Freundlich,Temkin etc.are only the special cases.Assuming uniform density distributionof adsorption energy,the isotherm equation is given asn=K.1n[1+（bop）1/Mor n=K.1n[1+（boC）1/M]where n is the amount of adsorption per unit weight or area of solid p or C is tbe pressure of gas or the concen-tration of solution respectively.K,bo,M are constants with physical meanings as described in this paper.This equation can be used over wide range to quantitatively represent the five types of physical adsorptionclassified by Brunauer.展开更多
Corrugated reactors are known for their use in applications requiring UV-exposure, whereby media flowing within the corrugated channel react with a photo-active catalyst impregnated on the surface （i.e. TiO2）. The p...Corrugated reactors are known for their use in applications requiring UV-exposure, whereby media flowing within the corrugated channel react with a photo-active catalyst impregnated on the surface （i.e. TiO2）. The performance in these systems is dependent on catalyst properties and reactivity for a given light source, in conjunc-tion with the coupled transport of reactants within the media and photons falling incident to the catalyst surface. Experimental and computational analyses of local mass transfer and radiation pattems for a broad range of corrugation angles, depths, and non-idealities introduced during manufacture （i.e. fold curvature） are thus integrated to the design and optimization of these systems. This work explores techniques for determining incident energy distribu-tions on the surface of corrugated reactor geometries with non-ideal cross-sectional profiles, and the local and overall mass transfer rates obtained using computational fluid dynamics and experimental analysis. By examining the reaction kinetics for the photo-degradation of 4-chlorophenol over a TiO2 catalyst, the effects of surface area, energy incidence with photon recapture, and local mass transfer on overall reactor performance are presented to highlight ootimization concerns for these tvoes of reactors.展开更多
An entanglement purification protocol for mixed entangled states is presented via double quantum dot molecules inside a superconducing transmission line resonator （TLR）. In the current scenario, coupling for arbitra...An entanglement purification protocol for mixed entangled states is presented via double quantum dot molecules inside a superconducing transmission line resonator （TLR）. In the current scenario, coupling for arbitrary double quantum dot molecules can be tuned via the TLR in the large detuning region by controlling the qubit level splitting. The TLR is always empty and only virtually excited, so the interaction is insensitive to both the TLR decay and thermal field. Discussion about the feasibility of our scheme shows that the entanglement purification can be implemented with high fidelity and successful probability.展开更多
Contaminated surfaces play a significant role in the transmission of respiratory infectious diseases.To address this issue,we pre-sented a novel quantitative detection method for droplets on physical surfaces,based on...Contaminated surfaces play a significant role in the transmission of respiratory infectious diseases.To address this issue,we pre-sented a novel quantitative detection method for droplets on physical surfaces,based on the laser-induced fluorescence technique.The proposed detection method was demonstrated in a realistic high-speed train compartment scenario by simulating the process of droplet release during passengers’breathing and coughing.The experimental results showed that this method could offer high precision(10-1 mg/m^(2))for detecting minute substance concentrations,and its ease of operation makes it suitable for complex en-gineering environments.The results also revealed that under the combined effects of the indoor airflow and breathing airflow,the range of droplets released by breathing activity exceeded two rows in front of and behind the release position.Simultaneously,we observed that a large number of droplets settled on the seat surfaces on both sides of the same row as the releaser,with over 36%of these droplets concentrated on the backrest area of the seats.As the respiratory jet velocity increased,the location with the most sed-iment droplets(accounting for 8%of the total sedimentation)occurred on the seat directly in front of the releaser,and approximately 48% of the droplets were found on the back of this seat.Our proposed method overcomes the shortcomings of existing experimental methods in quantitatively capturing the motion characteristics of droplets in complex flow fields.展开更多
An iterative physical optics（IPO） model is proposed to solve extra large scale electric electromagnetic（EM） scattering from randomly rough surfaces. In order to accelerate the convergence of the IPO model, the for...An iterative physical optics（IPO） model is proposed to solve extra large scale electric electromagnetic（EM） scattering from randomly rough surfaces. In order to accelerate the convergence of the IPO model, the forward-backward methodology and its modification with underrelaxation iteration are developed to simulate the rough surface scattering; the local iteration methodology and the fast far field approximation（Fa FFA） in the matrix-vector product are proposed to reduce greatly the computational complexity. These techniques make Monte Carlo simulations possible. Thus, the average Doppler spectra of backscattered signals obtained from the simulations are compared for different incident angles and sea states. In particular, the simulations show a broadening of the Doppler spectra for a more complicated sea state at a low grazing angle（LGA）.展开更多
Based on the basic principles of atmospheric boundary layer and plant canopy micrometeorology, a forest underlying surface land surface physical process model and a two-dimensional atmospheric boundary layer numerical...Based on the basic principles of atmospheric boundary layer and plant canopy micrometeorology, a forest underlying surface land surface physical process model and a two-dimensional atmospheric boundary layer numerical model are developed and numerical simulation experiments of biosphere and physiological processes of vegetation and soil volumetric water content have been done on land surface processes with local climate effect. The numerical simulation results are in good agreement with realistic observations, which can be used to obtain reasonable simulations for diurnal variations of canopy temperature, air temperature in canopy, ground surface temperature, and temporal and spatial distributions of potential temperature and vertical wind velocity as well as relative humidity and turbulence exchange coefficient over non-homogeneous underlying surfaces. It indicates that the model developed can be used to study the interaction between land surface process and atmospheric boundary layer over various underlying surfaces and can be extended to local climate studies. This work will settle a solid foundation for coupling climate models with the biosphere.展开更多
Bitumen requirement in hot mix asphalt （HMA） is directly dependent on the surface area of the aggregates in the mix, which in turn has effect on the asphalt film thickness and the flow characteristics. The surface a...Bitumen requirement in hot mix asphalt （HMA） is directly dependent on the surface area of the aggregates in the mix, which in turn has effect on the asphalt film thickness and the flow characteristics. The surface area of aggregate blend in HMA is calculated using the specific surface area factors assigned to percentage passing through some specific standard sieve sizes and the imaging techniques. The first process is less capital intensive, but purely manual and labour intensive and prone to human errors. Imaging techniques though eliminating the human errors, still have limited use due to capital intensiveness and requirement of well-established ]aboratories with qualified technicians. Most of the developing countries like India are shortage of well-equipped laboratories and qualified technicians. To overcome these difficulties, the present mathematical model has been developed to estimate the surface area of aggregate blend of HMA from physical properties of aggregates evaluated using simple laboratory equipment. This model has been validated compared with the existing established methods of calculations and can be used as one of the tools in different developing and under developed countries for proper design of HMA.展开更多
An empirical simulation method to simulate the possible position of shallow rainfall-induced landslides in China has been developed.This study shows that such a simulation may be operated in real-time to highlight tho...An empirical simulation method to simulate the possible position of shallow rainfall-induced landslides in China has been developed.This study shows that such a simulation may be operated in real-time to highlight those areas that are highly prone to rainfall-induced landslides on the basis of the landslide susceptibility index and the rainfall intensity-duration(I-D) thresholds.First,the study on landslide susceptibility in China is introduced.The entire territory has been classified into five categories,among which high-susceptibility regions(Zone 4-'High' and 5-'Very high') account for 4.15%of the total extension of China.Second,rainfall is considered as an external triggering factor that may induce landslide initiation.Real-time satellite-based TMPA3B42 products may provide real rainfall spatial and temporal patterns,which may be used to derive rainfall duration time and intensity.By using a historical record of 60 significant past landslides,the rainfall I-D equation has been calibrated.The rainfall duration time that may trigger a landslide has resulted between 3 hours and 45 hours.The combination of these two aspects can be exploited to simulate the spatiotemporal distribution of rainfall-induced landslide hazards when rainfall events exceed the rainfall I-D thresholds,where the susceptibility category is 'high' or 'very high'.This study shows a useful tool to be part of a systematic landslide simulation methodology,potentially providing useful information for a theoretical basis and practical guide for landslide prediction and mitigation throughout China.展开更多
文摘1.ObjectivesLaboratory for Surface Physics ofAcademia Sinica(LSPAS)was establishedin 1987 for enhancing the research activity insurface sciences,according to the NationalLaboratory Project of the State PlanningCommittee.During the last 30 years,we have wit-nessed a tremendous development in surfacephysics.Photoemission spectroscopy(1981Nobel prize to Siegbahn for ESCA)offers
基金National Natural Science Foundation of China (No. 40275004)State Key Laboratory of Atmosphere Physics and Chemistry
文摘Based on the existing Land Surface Physical Process Models(Deardorff, Dickinson, LIU, Noilhan, Seller, ZHAO), a Comprehensive Land Surface Physical Process Model (CLSPPM) is developed by considering the different physical processes of the earth's surface-vegetation-atmosphere system more completely. Compared with SiB and BATS, which are famous for their detailed parameterizations of physical variables, this simplified model is more convenient and saves much more computation time. Though simple, the feas...
文摘The principal assumptions about equivalence and energy distribution of the asdorption sites on solidsurfaces used by Langmuir for deriving the equation of monomolecular adsorption are generalized and anew physical adsorption model is proposed and tested with experimental data published in literature.Themodels of Langmuir,Freundlich,Temkin etc.are only the special cases.Assuming uniform density distributionof adsorption energy,the isotherm equation is given asn=K.1n[1+（bop）1/Mor n=K.1n[1+（boC）1/M]where n is the amount of adsorption per unit weight or area of solid p or C is tbe pressure of gas or the concen-tration of solution respectively.K,bo,M are constants with physical meanings as described in this paper.This equation can be used over wide range to quantitatively represent the five types of physical adsorptionclassified by Brunauer.
文摘Corrugated reactors are known for their use in applications requiring UV-exposure, whereby media flowing within the corrugated channel react with a photo-active catalyst impregnated on the surface （i.e. TiO2）. The performance in these systems is dependent on catalyst properties and reactivity for a given light source, in conjunc-tion with the coupled transport of reactants within the media and photons falling incident to the catalyst surface. Experimental and computational analyses of local mass transfer and radiation pattems for a broad range of corrugation angles, depths, and non-idealities introduced during manufacture （i.e. fold curvature） are thus integrated to the design and optimization of these systems. This work explores techniques for determining incident energy distribu-tions on the surface of corrugated reactor geometries with non-ideal cross-sectional profiles, and the local and overall mass transfer rates obtained using computational fluid dynamics and experimental analysis. By examining the reaction kinetics for the photo-degradation of 4-chlorophenol over a TiO2 catalyst, the effects of surface area, energy incidence with photon recapture, and local mass transfer on overall reactor performance are presented to highlight ootimization concerns for these tvoes of reactors.
基金Supported by the National Natural Science Foundation of China under Grant Nos 60678022 and 10704001, the Specialized Research Pund for the Doctoral Program of Higher Education under Grant No 20060357008, the Key Program of the Education Department of Anhui Province under Grant Nos KJ2009A048Z, the Talent Project of the Anhui Province for Outstanding Youth under Grant Nos 2010SQRL153ZD and 2010SQRL187.
文摘An entanglement purification protocol for mixed entangled states is presented via double quantum dot molecules inside a superconducing transmission line resonator （TLR）. In the current scenario, coupling for arbitrary double quantum dot molecules can be tuned via the TLR in the large detuning region by controlling the qubit level splitting. The TLR is always empty and only virtually excited, so the interaction is insensitive to both the TLR decay and thermal field. Discussion about the feasibility of our scheme shows that the entanglement purification can be implemented with high fidelity and successful probability.
基金supported by the National Natural Science Foun-dation of China(Grant No.52072413)the graduate school of Central South University(Grant No.1053320213788).
文摘Contaminated surfaces play a significant role in the transmission of respiratory infectious diseases.To address this issue,we pre-sented a novel quantitative detection method for droplets on physical surfaces,based on the laser-induced fluorescence technique.The proposed detection method was demonstrated in a realistic high-speed train compartment scenario by simulating the process of droplet release during passengers’breathing and coughing.The experimental results showed that this method could offer high precision(10-1 mg/m^(2))for detecting minute substance concentrations,and its ease of operation makes it suitable for complex en-gineering environments.The results also revealed that under the combined effects of the indoor airflow and breathing airflow,the range of droplets released by breathing activity exceeded two rows in front of and behind the release position.Simultaneously,we observed that a large number of droplets settled on the seat surfaces on both sides of the same row as the releaser,with over 36%of these droplets concentrated on the backrest area of the seats.As the respiratory jet velocity increased,the location with the most sed-iment droplets(accounting for 8%of the total sedimentation)occurred on the seat directly in front of the releaser,and approximately 48% of the droplets were found on the back of this seat.Our proposed method overcomes the shortcomings of existing experimental methods in quantitatively capturing the motion characteristics of droplets in complex flow fields.
基金supported by the National Natural Science Foundation of China(61372033)
文摘An iterative physical optics（IPO） model is proposed to solve extra large scale electric electromagnetic（EM） scattering from randomly rough surfaces. In order to accelerate the convergence of the IPO model, the forward-backward methodology and its modification with underrelaxation iteration are developed to simulate the rough surface scattering; the local iteration methodology and the fast far field approximation（Fa FFA） in the matrix-vector product are proposed to reduce greatly the computational complexity. These techniques make Monte Carlo simulations possible. Thus, the average Doppler spectra of backscattered signals obtained from the simulations are compared for different incident angles and sea states. In particular, the simulations show a broadening of the Doppler spectra for a more complicated sea state at a low grazing angle（LGA）.
基金Supported by the National Natural Science Foundation of China under Grant Nos. 40275004 and 49575251.
文摘Based on the basic principles of atmospheric boundary layer and plant canopy micrometeorology, a forest underlying surface land surface physical process model and a two-dimensional atmospheric boundary layer numerical model are developed and numerical simulation experiments of biosphere and physiological processes of vegetation and soil volumetric water content have been done on land surface processes with local climate effect. The numerical simulation results are in good agreement with realistic observations, which can be used to obtain reasonable simulations for diurnal variations of canopy temperature, air temperature in canopy, ground surface temperature, and temporal and spatial distributions of potential temperature and vertical wind velocity as well as relative humidity and turbulence exchange coefficient over non-homogeneous underlying surfaces. It indicates that the model developed can be used to study the interaction between land surface process and atmospheric boundary layer over various underlying surfaces and can be extended to local climate studies. This work will settle a solid foundation for coupling climate models with the biosphere.
文摘Bitumen requirement in hot mix asphalt （HMA） is directly dependent on the surface area of the aggregates in the mix, which in turn has effect on the asphalt film thickness and the flow characteristics. The surface area of aggregate blend in HMA is calculated using the specific surface area factors assigned to percentage passing through some specific standard sieve sizes and the imaging techniques. The first process is less capital intensive, but purely manual and labour intensive and prone to human errors. Imaging techniques though eliminating the human errors, still have limited use due to capital intensiveness and requirement of well-established ]aboratories with qualified technicians. Most of the developing countries like India are shortage of well-equipped laboratories and qualified technicians. To overcome these difficulties, the present mathematical model has been developed to estimate the surface area of aggregate blend of HMA from physical properties of aggregates evaluated using simple laboratory equipment. This model has been validated compared with the existing established methods of calculations and can be used as one of the tools in different developing and under developed countries for proper design of HMA.
基金supported by the National Natural Science Foundation of China(Grant No.41501458)China Postdoctoral Science Foundation Funded Project(Grant No.2016M592860)+4 种基金National Basic Research Program of China(Grant No.2013CB733204)Key Laboratory of Mining Spatial Information Technology of NASMG(Grant Nos. KLM201309)Science Program of Shanghai Normal University(Grant No. SK201525)the Shanghai Gaofeng & Gaoyuan Project for University Academic Program Development(Grant Nos.2013LASW-A09 & SKHL1310)the Center of Spatial Information Science and Sustainable Development Applications,Tongji University,Shanghai,China
文摘An empirical simulation method to simulate the possible position of shallow rainfall-induced landslides in China has been developed.This study shows that such a simulation may be operated in real-time to highlight those areas that are highly prone to rainfall-induced landslides on the basis of the landslide susceptibility index and the rainfall intensity-duration(I-D) thresholds.First,the study on landslide susceptibility in China is introduced.The entire territory has been classified into five categories,among which high-susceptibility regions(Zone 4-'High' and 5-'Very high') account for 4.15%of the total extension of China.Second,rainfall is considered as an external triggering factor that may induce landslide initiation.Real-time satellite-based TMPA3B42 products may provide real rainfall spatial and temporal patterns,which may be used to derive rainfall duration time and intensity.By using a historical record of 60 significant past landslides,the rainfall I-D equation has been calibrated.The rainfall duration time that may trigger a landslide has resulted between 3 hours and 45 hours.The combination of these two aspects can be exploited to simulate the spatiotemporal distribution of rainfall-induced landslide hazards when rainfall events exceed the rainfall I-D thresholds,where the susceptibility category is 'high' or 'very high'.This study shows a useful tool to be part of a systematic landslide simulation methodology,potentially providing useful information for a theoretical basis and practical guide for landslide prediction and mitigation throughout China.
