The paper proposes a new method to estimate nonlinear diffusions based on discretely observed data, and gives some properties of the corresponding parameters estimation.
Density functional theory calculations corrected by on-site Coulomb interactions were carried out o study the structures of polar CeO2 （100） surfaces as well as activities during catalytic CO oxidation. The stabilit...Density functional theory calculations corrected by on-site Coulomb interactions were carried out o study the structures of polar CeO2 （100） surfaces as well as activities during catalytic CO oxidation. The stabilities of various CeO2 （100） termination structures are discussed, and calculated energetics are presented. The most stable Ce〇2 （100） surface was obtained by removing half the outermost full layer of oxygen and the surface stability was found to decrease as the exposed oxygen concentration was increased. Assessing the reaction pathways leading to different final products during CO oxidation over the most stable CeO2 （100） surface, we determined that the formation of carbonate species competed with CO2 desorption. However, during CO oxidation on the less stable CeO2 （100） surfaces having more exposed oxygen, the CO is evidently able to react with surface oxygen, leading to CO2 formation and desorption. The calculation results and electronic analyses reported herein also indicate that the characteristic Ce 4/ orbitals are directly involved in deter-mining the surface stabilities and reactivities.展开更多
The reliability of post grouting pile axial resistance was studied by proposing a design method for its probabilistic limit state,which is represented by the partial coefficients of load,end,and side resistance.The hy...The reliability of post grouting pile axial resistance was studied by proposing a design method for its probabilistic limit state,which is represented by the partial coefficients of load,end,and side resistance.The hyperbolic,modified hyperbolic,and polynomial models were employed to predict the ultimate bearing capacity of test piles that were not loaded to damage in field tests.The results were used for the calculation and calibration of the reliability index.The reliability of the probabilistic limit state design method was verified by an engineering case.The results show that the prediction results obtained from the modified hyperbolic model are closest to those obtained through the static load test.The proposed corresponding values of total,side,and end resistance partial coefficients are 1.84,1.66,and 2.73 when the dead and live load partial coefficients are taken as 1.1 and 1.4,respectively.Meanwhile,the corresponding partial coefficients of total,side,and end resistance are 1.70,1.56,and 2.34 when the dead and live load partial coefficients are taken as 1.2 and 1.4,respectively.展开更多
The density functional theory, simplified by the local density approximation and mean-field approxi-mation, is applied to study the surface properties of pure non-polar fluids. A reasonable long rang correction is ado...The density functional theory, simplified by the local density approximation and mean-field approxi-mation, is applied to study the surface properties of pure non-polar fluids. A reasonable long rang correction is adopted to avoid the truncation of the potential. The perturbation theory is applied to establish the equation for the phase equilibrium, in which the hard-core chain fluid is as the reference fluid and the Yukawa potential is used as the perturbation term. Three parameters, ε/κ, d and ms, are regressed frorn the vapor-liquid equilibria, and the surface properties, including density profile, surface tension and local surface tension profile are predicted with these parameters.展开更多
The stability of dams and their foundations is an important problem to which dam engineers have paid close attention over the years. This paper presented two methods to analyze the stability of a gravity dam and its f...The stability of dams and their foundations is an important problem to which dam engineers have paid close attention over the years. This paper presented two methods to analyze the stability of a gravity dam and its foundation. The direct analysis method was based on a rigid limit equilibrium method which regarded both dam and the rock foundation as undeformable rigid bodies. In this method, the safety factor of potential sliding surfaces was computed directly. The second method, the indirect analysis method, was based on elasto-plastic theory and employs nonlinear finite element method (FEM) in the analysis of stresses and deformation in the dam and its foundation. The determination of the safety degree of the structure was based on the convergence and abrupt the change criterion. The results obtained showed that structures' constituent material behavior played an active role in the failure of engineered structures in addition to the imposed load.展开更多
In this paper the anomalous magnetic dipole moment ofmuon in the littlest Higgs （LH） model is studied at one-loop level. We discuss the dependence of the contributions on the global symmetry breaking scale f, mizing...In this paper the anomalous magnetic dipole moment ofmuon in the littlest Higgs （LH） model is studied at one-loop level. We discuss the dependence of the contributions on the global symmetry breaking scale f, mizing angles c` and , and the Higgs triplet vacuum expectation value v＇ in the electroweak precision data preferring ranges. We find that the LH model can give a relatively small, but non-negligible extra weak contribution to the muon anomalous magnetic moment and can reduce the deviation of △aμ from 2.6σ for the SM to 2.5σ for the LH model.展开更多
The mechanism and regioselectivity of 1,3-dipolar cycloaddition of N-[methyl]-C-[5-nitro-2-furyl] nitrilimine with dimethyl 7-oxabicyclo[2,2,1]hepta-2,5-diene-2,3-dicarboxylate were investigated using activation energ...The mechanism and regioselectivity of 1,3-dipolar cycloaddition of N-[methyl]-C-[5-nitro-2-furyl] nitrilimine with dimethyl 7-oxabicyclo[2,2,1]hepta-2,5-diene-2,3-dicarboxylate were investigated using activation energy calculations and density functional theory-based reactivity indexes. The reaction proceeds by an asynchronous concerted mechanism. The calculations are performed at the B3LYP/6-31G（d） level of theory and the obtained results are in agreement with experimental outcome.展开更多
The elastic property and sound velocity of FeaC under high pressure are investigated by using the spin-polarized generalized gradient approximation within density-functional theory. It is found that the magnetic phase...The elastic property and sound velocity of FeaC under high pressure are investigated by using the spin-polarized generalized gradient approximation within density-functional theory. It is found that the magnetic phase transition from the ground ferromagnetic （FM） state to the nonmagnetic （NM） state occurs at ～73 GPa. Based on the predicted Hugoniot of Fe3C, we calculate the sound velocities of FM-Fe3C and NM-Fe3C from elastic constants. Compared with pure iron, NM-FeaC provides a better match of compressional and shear sound velocities with the seismic data of the inner core, supporting carbon as one of the light elements in the inner core.展开更多
TiNb2O7 anode materials(TNO)have unique potential for applications in Li-ion capacitors(LICs)due to their high specific capacity of ca.280 mA h g^-1 over a wide anodic Li-insertion potential window.However,their highr...TiNb2O7 anode materials(TNO)have unique potential for applications in Li-ion capacitors(LICs)due to their high specific capacity of ca.280 mA h g^-1 over a wide anodic Li-insertion potential window.However,their highrate capability is limited by their poor electronic and ionic conductivity.In particular,studies on TNO for LICs are lacking and that for flexible LICs have not yet been reported.Herein,a unique TNO porous electrode with cross-linked nanorods tailored by post-annealing and its application in flexible LICs are reported.This binder-free TNO anode exhibits superior rate performance(~66.3%capacity retention as the rate increases from 1 to 40 C),which is ascribed to the greatly shortened ion-diffusion length in TNO nanorods,facile electrolyte penetration and fast electron transport along the continuous single-crystalline nanorod network.Furthermore,the TNO anode shows an excellent cycling stability up to 2000 cycles and good flexibility(no capacity loss after continuous bending for 500 times).Model flexible LIC assembled with the TNO anode and activated carbon cathode exhibits increased gravimetric and volumetric energy/power densities(~100.6 W h kg^-1/4108.8 W kg^-1;10.7 mW h cm^-3/419.3 mW cm^-3),more superior to previously reported hybrid supercapacitors.The device also efficiently powers an LED light upon 180°bending.展开更多
文摘The paper proposes a new method to estimate nonlinear diffusions based on discretely observed data, and gives some properties of the corresponding parameters estimation.
基金supported the National Natural Science Foundation of China(21421004,21573067)~~
文摘Density functional theory calculations corrected by on-site Coulomb interactions were carried out o study the structures of polar CeO2 （100） surfaces as well as activities during catalytic CO oxidation. The stabilities of various CeO2 （100） termination structures are discussed, and calculated energetics are presented. The most stable Ce〇2 （100） surface was obtained by removing half the outermost full layer of oxygen and the surface stability was found to decrease as the exposed oxygen concentration was increased. Assessing the reaction pathways leading to different final products during CO oxidation over the most stable CeO2 （100） surface, we determined that the formation of carbonate species competed with CO2 desorption. However, during CO oxidation on the less stable CeO2 （100） surfaces having more exposed oxygen, the CO is evidently able to react with surface oxygen, leading to CO2 formation and desorption. The calculation results and electronic analyses reported herein also indicate that the characteristic Ce 4/ orbitals are directly involved in deter-mining the surface stabilities and reactivities.
基金The National Natural Science Foundation of China(No.51878160,52008100,52078128).
文摘The reliability of post grouting pile axial resistance was studied by proposing a design method for its probabilistic limit state,which is represented by the partial coefficients of load,end,and side resistance.The hyperbolic,modified hyperbolic,and polynomial models were employed to predict the ultimate bearing capacity of test piles that were not loaded to damage in field tests.The results were used for the calculation and calibration of the reliability index.The reliability of the probabilistic limit state design method was verified by an engineering case.The results show that the prediction results obtained from the modified hyperbolic model are closest to those obtained through the static load test.The proposed corresponding values of total,side,and end resistance partial coefficients are 1.84,1.66,and 2.73 when the dead and live load partial coefficients are taken as 1.1 and 1.4,respectively.Meanwhile,the corresponding partial coefficients of total,side,and end resistance are 1.70,1.56,and 2.34 when the dead and live load partial coefficients are taken as 1.2 and 1.4,respectively.
基金Supported by the National Natural Science Foundation of China (No. 20102007) and the Fundamental Research Fund of Tsinghua University of China (No. JZ2002003).
文摘The density functional theory, simplified by the local density approximation and mean-field approxi-mation, is applied to study the surface properties of pure non-polar fluids. A reasonable long rang correction is adopted to avoid the truncation of the potential. The perturbation theory is applied to establish the equation for the phase equilibrium, in which the hard-core chain fluid is as the reference fluid and the Yukawa potential is used as the perturbation term. Three parameters, ε/κ, d and ms, are regressed frorn the vapor-liquid equilibria, and the surface properties, including density profile, surface tension and local surface tension profile are predicted with these parameters.
文摘The stability of dams and their foundations is an important problem to which dam engineers have paid close attention over the years. This paper presented two methods to analyze the stability of a gravity dam and its foundation. The direct analysis method was based on a rigid limit equilibrium method which regarded both dam and the rock foundation as undeformable rigid bodies. In this method, the safety factor of potential sliding surfaces was computed directly. The second method, the indirect analysis method, was based on elasto-plastic theory and employs nonlinear finite element method (FEM) in the analysis of stresses and deformation in the dam and its foundation. The determination of the safety degree of the structure was based on the convergence and abrupt the change criterion. The results obtained showed that structures' constituent material behavior played an active role in the failure of engineered structures in addition to the imposed load.
基金The project supported in part by National Natural Science Foundation of China and Special Fund sponsored by the Chinese Academy of Sciences
文摘In this paper the anomalous magnetic dipole moment ofmuon in the littlest Higgs （LH） model is studied at one-loop level. We discuss the dependence of the contributions on the global symmetry breaking scale f, mizing angles c` and , and the Higgs triplet vacuum expectation value v＇ in the electroweak precision data preferring ranges. We find that the LH model can give a relatively small, but non-negligible extra weak contribution to the muon anomalous magnetic moment and can reduce the deviation of △aμ from 2.6σ for the SM to 2.5σ for the LH model.
文摘The mechanism and regioselectivity of 1,3-dipolar cycloaddition of N-[methyl]-C-[5-nitro-2-furyl] nitrilimine with dimethyl 7-oxabicyclo[2,2,1]hepta-2,5-diene-2,3-dicarboxylate were investigated using activation energy calculations and density functional theory-based reactivity indexes. The reaction proceeds by an asynchronous concerted mechanism. The calculations are performed at the B3LYP/6-31G（d） level of theory and the obtained results are in agreement with experimental outcome.
基金ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China （No.11247316, No.11247317, No.11347019, No.11304408, and No.U1230201）, the Science and Technology Research Project of Chongqing Education Committee （No.K J120613 and No.KJ130607）, and the Natural Science Foundation of Chongqing City （No.cstc2012jjA50019 and No.cstc2013jcyjA0733）.
文摘The elastic property and sound velocity of FeaC under high pressure are investigated by using the spin-polarized generalized gradient approximation within density-functional theory. It is found that the magnetic phase transition from the ground ferromagnetic （FM） state to the nonmagnetic （NM） state occurs at ～73 GPa. Based on the predicted Hugoniot of Fe3C, we calculate the sound velocities of FM-Fe3C and NM-Fe3C from elastic constants. Compared with pure iron, NM-FeaC provides a better match of compressional and shear sound velocities with the seismic data of the inner core, supporting carbon as one of the light elements in the inner core.
基金supported by the National Natural Science Foundation of China (51672205, 21673169 and 51972257)the National Key R&D Program of China (2016YFA0202602)the Natural Science Foundation of Hubei Province (2018CFB581)
文摘TiNb2O7 anode materials(TNO)have unique potential for applications in Li-ion capacitors(LICs)due to their high specific capacity of ca.280 mA h g^-1 over a wide anodic Li-insertion potential window.However,their highrate capability is limited by their poor electronic and ionic conductivity.In particular,studies on TNO for LICs are lacking and that for flexible LICs have not yet been reported.Herein,a unique TNO porous electrode with cross-linked nanorods tailored by post-annealing and its application in flexible LICs are reported.This binder-free TNO anode exhibits superior rate performance(~66.3%capacity retention as the rate increases from 1 to 40 C),which is ascribed to the greatly shortened ion-diffusion length in TNO nanorods,facile electrolyte penetration and fast electron transport along the continuous single-crystalline nanorod network.Furthermore,the TNO anode shows an excellent cycling stability up to 2000 cycles and good flexibility(no capacity loss after continuous bending for 500 times).Model flexible LIC assembled with the TNO anode and activated carbon cathode exhibits increased gravimetric and volumetric energy/power densities(~100.6 W h kg^-1/4108.8 W kg^-1;10.7 mW h cm^-3/419.3 mW cm^-3),more superior to previously reported hybrid supercapacitors.The device also efficiently powers an LED light upon 180°bending.
