A fully flexible potential model for carbon dioxide has been developed to predict the vapor-liquid coexistence properties using the NVT-Gibbs ensemble Monte Carlo technique(GEMC).The average absolute deviation between...A fully flexible potential model for carbon dioxide has been developed to predict the vapor-liquid coexistence properties using the NVT-Gibbs ensemble Monte Carlo technique(GEMC).The average absolute deviation between our simulation and the literature experimental data for saturated liquid and vapor densities is 0.3% and 2.0%,respectively.Compared with the experimental data,our calculated results of critical properties(7.39 MPa,304.04 K,and 0.4679 g?cm-3) are acceptable and are better than those from the rescaling the potential parameters of elementary physical model(EPM2).The agreement of our simulated densities of supercritical carbon dioxide with the experimental data is acceptable in a wide range of pressure and temperature.The radial distribution function estimated at the supercritical conditions suggests that the carbon dioxide is a nonlinear molecule with the C O bond length of 0.117 nm and the O C O bond angle of 176.4°,which are consistent with Car-Parrinello molecular-dynamics(CPMD),whereas the EPM2 model shows large deviation at supercritical state.The predicted self-diffusion coefficients are in agreement with the experiments.展开更多
An analytical potential for cylindrical pores has been derived by introducing a variational method into the integration for the calculation of the interaction energy between the wall molecules and a test molecule, all...An analytical potential for cylindrical pores has been derived by introducing a variational method into the integration for the calculation of the interaction energy between the wall molecules and a test molecule, all of which are represented by Lennard-Jones potential. The model proposed gives good fit to the results from the cylindrical surface model and the pseudoatom model. To test the potential proposed rigorously, we have carried out grand canonical ensemble Monte Carlo(GCMC) simulation of nitrogen in the MCM-41 pore at 77 K, and compared the simulated adsorption isotherm with the experimental data reported in the literature. The simulated isotherm from our model is in almost qualitative agreement with experiment. Consequently, the model proposed provides an explicit and accurate description of cylindrical pores represented by the Lennard-Jones potential. Moreover, the model can be easily applied to a variety of cylindrical pores, ranging from cylindrical surface to finite thickness walls, in both theoretical studies and computer simulations.展开更多
Based on the accurate and efficient thermal injection method, we develop a fully analytical surface potential model for the heterojunction tunnel field-effect transistor(H-TFET). This model accounts for both the effec...Based on the accurate and efficient thermal injection method, we develop a fully analytical surface potential model for the heterojunction tunnel field-effect transistor(H-TFET). This model accounts for both the effects of source depletion and inversion charge, which are the key factors influencing the charge, capacitance and current in H-TFET. The accuracy of the model is validated against TCAD simulation and is greatly improved in comparison with the conventional model based on Maxwell–Boltzmann approximation. Furthermore, the dependences of the surface potential and electric field on biases are well predicted and thoroughly analyzed.展开更多
The quark potential model is used to investigate the low-energy elastic scattering of πN system. The model potential consists of the t-channel and s-channel one-gluon exchange potentials and the harmonic oscillator c...The quark potential model is used to investigate the low-energy elastic scattering of πN system. The model potential consists of the t-channel and s-channel one-gluon exchange potentials and the harmonic oscillator confining potential. By means of the resonating group method, a nonlocal effective potential for the πN system is derived from the interquark potentials and used to calculate the πN elastic scattering phase shifts. By considering the effect of QCD renormalization, the suppression of the spin-orbital coupling and the contribution of the color octet of the clusters （qq） and （qqq）, the numerical results are in fairly good agreement with the experimental data. The same model and method are employed to investigate the possible πN resonances. For this purpose, the resonating group equation is transformed into a standard Schrodinger equation in which the nonlocal effective πN interaction potential is included. Solving the Schrodinger equation by the variational method, we are able to reproduce the masses of some currently concerned πN resonances.展开更多
Using the numerical solution of the time-dependent SchrSdinger equation of a one-dimensional model atom in a two-colour laser field, we have investigated the effects of the potential models on coherent control of atom...Using the numerical solution of the time-dependent SchrSdinger equation of a one-dimensional model atom in a two-colour laser field, we have investigated the effects of the potential models on coherent control of atomic multiphoton ionization. It is found that the photoelectron spectra are obviously different for the long-range （Coulomb-like） and short-range （with no excited bound states） potential model atoms, which are produced by two-colour coherent control of atomic multiphoton ionization in a few laser cycles. Our results indicate that two-colour coherent control of atomic multiphoton ionization can be observed in simulations, depending on the choice of the model potentials.展开更多
This work conducts a comprehensive analysis of the mass spectra and decay properties of bottomonium states using a relativistic screened potential model. The mass spectrum, decay constants, E 1 transi tions, M 1 trans...This work conducts a comprehensive analysis of the mass spectra and decay properties of bottomonium states using a relativistic screened potential model. The mass spectrum, decay constants, E 1 transi tions, M 1 transitions, and annihilation decay widths are evaluated. The interpretation of Υ(10355), Υ(10580), Υ(10860), and Υ(11020) a s S-D mixed bottomonium states are analysed. The Υ(10355) state is considered to be 3S-2D,Υ(10580) an d Υ(10753) are consid ered to be 4S-3D mixed states, and the Υ(10860) an d Υ(11020) are considered to be 5S-4D mixed states.展开更多
The carbon emissions and cost during the construction phase are significant contributors to the oilfield lifecycle.As oilfields enter the late stage,the adaptability of facilities decreases.To achieve sustainable deve...The carbon emissions and cost during the construction phase are significant contributors to the oilfield lifecycle.As oilfields enter the late stage,the adaptability of facilities decreases.To achieve sustainable development,oilfield reconstruction was usually conducted in discrete rather than continuous space.Motivated by economic and sustainability goals,a 3-phase heuristic model for oilfield reconstruction was developed to mine potential locations in continuous space.In phase 1,considering the process characteristics of the oil and gas gathering system,potential locations were mined in continuous space.In phase 2,incorporating comprehensive reconstruction measures,a reconstruction model was established in discrete space.In phase 3,the topology was further adjusted in continuous space.Subsequently,the model was transformed into a single-objective mixed integer linear programming model using the augmented ε-constraint method.Numerical experiments revealed that the small number of potential locations could effectively reduce the reconstruction cost,and the quality of potential locations mined in phase 1 surpassed those generated in random or grid form.Case studies showed that cost and carbon emissions for a new block were reduced by up to 10.45% and 7.21 %,respectively.These reductions were because the potential locations mined in 1P reduced the number of metering stations,and 3P adjusted the locations of metering stations in continuous space to shorten the pipeline length.For an old oilfield,the load and connection ratios of the old metering station increased to 89.7% and 94.9%,respectively,enhancing operation efficiency.Meanwhile,recycling facilitated the diversification of reconstruction measures and yielded a profit of 582,573 ¥,constituting 5.56% of the total cost.This study adopted comprehensive reconstruction measures and tapped into potential reductions in cost and carbon emissions for oilfield reconstruction,offering valuable insights for future oilfield design and construction.展开更多
In the QCD-inspired potential model where the quark-antiquark interaction consists of the usual one- gluon-exchange and the mixture of long-range scalar and vector linear confining potentials with the lowest order rel...In the QCD-inspired potential model where the quark-antiquark interaction consists of the usual one- gluon-exchange and the mixture of long-range scalar and vector linear confining potentials with the lowest order relativistic correction, we investigate the mass spectra and electromagnetic processes of a bottomonium system by using the Gaussian expansion method. It reveals that the vector component of the mixing confinement is anticonfining and takes around 18.51% of the confining potential. Combining the new experimental data released by Belle, BaBar and LHC, we systematically discuss the energy levels of the bottomouium states and make the predictions of the electromagnetic decays for further experiments.展开更多
Considering the preformation probability of the two emitted protons in the parent nucleus,we extend the Coulomb and proximity potential model(CPPM)to systematically study two-proton(2p)radioactivity half-lives of the ...Considering the preformation probability of the two emitted protons in the parent nucleus,we extend the Coulomb and proximity potential model(CPPM)to systematically study two-proton(2p)radioactivity half-lives of the nuclei close to proton drip line.The proximity potential chosen is Prox.81 proposed by Blocki et al.in 1981.Furthermore,we apply this model to predict the half-lives of possible 2p radioactive candidates whose 2p radioactivity is energetically allowed or observed but not yet quantified in the evaluated nuclear properties table NUBASE2016.The predicted results are in good agreement with those from other theoretical models and empirical formulas,namely the effective liquid drop model(ELDM),generalized liquid drop model(GLDM),Gamow-like model,Sreeja formula and Liu formula.展开更多
A simple theoretical equation of state is derived by applying the Tower-Well potential model about the molecular distribution based on the generalized van der Waals partition function. It needs only three molecular pa...A simple theoretical equation of state is derived by applying the Tower-Well potential model about the molecular distribution based on the generalized van der Waals partition function. It needs only three molecular parameters which have distinct physical meanings. The resulting equation of state predicts rather well the Vapor pressures, saturate liquid volumes, saturated vapor volumes and PVT thermodynamic properties of polar and structurally complex molecules over a wide temperature and pressure range.展开更多
The electrostatic potential energy model of hydrotalcites was based on the theory of crystallography. The anionic potential energy of MgAl-hydrotalcites, with 20 layers and 2107 anions per layer, was calculated, and t...The electrostatic potential energy model of hydrotalcites was based on the theory of crystallography. The anionic potential energy of MgAl-hydrotalcites, with 20 layers and 2107 anions per layer, was calculated, and the anionic stability of the hydrotalcites was investigated. The charge density of the layer and the distance between the adjacent anions varied with the molar ratio of Al^3＋/（Mg^2＋ ＋ Al^3＋）. Anionic potential energy depended on the charge and size of the anions. Calculation results remained consistent with thermal stability and the ion exchange ability reported. This model is able to predict anionic stability of the hydrotalcites.展开更多
Potential evapotranspiration(EPET)is usually calculated by empirical methods from surface meteorological variables,such as temperature,radiation and wind speed.The in-situ measured pan evaporation(ETpan)can also be us...Potential evapotranspiration(EPET)is usually calculated by empirical methods from surface meteorological variables,such as temperature,radiation and wind speed.The in-situ measured pan evaporation(ETpan)can also be used as a proxy for EPET.In this study,EPET values computed from ten models are compared with observed ETpan data in ten Chinese river basins for the period 1961−2013.The daily observed meteorological variables at 2267 stations are used as the input to those models,and a ranking scheme is applied to rank the statistical quantities(ratio of standard deviations,correlation coefficient,and ratio of trends)between ETpan and modeled EPET in different river basins.There are large deviations between the modeled EPET and the ETpan in both the magnitude and the annual trend at most stations.In eight of the basins(except for Southeast and Southwest China),ETpan shows decreasing trends with magnitudes ranging between−0.01 mm d−1 yr−1 and−0.03 mm d−1 yr−1,while the decreasing trends in modeled EPET are less than−0.01 mm d−1 yr−1.Inter comparisons among different models in different river basins suggest that PETHam1 is the best model in the Pearl River basin,PETHam2 outperforms other models in the Huaihe River,Yangtze River and Yellow River basins,and PETFAO is the best model for the remaining basins.Sensitivity analyses reveal that wind speed and sunshine duration are two important factors for decreasing EPET in most basins except in Southeast and Southwest China.The increasing EPET trend in Southeast China is mainly attributed to the reduced relative humidity.展开更多
Using the density functional B3P86/cc-PV5Z method, the geometric structure of BH molecule under different external electric fields is optimized, and the bond lengths, dipole moments, vibration frequencies, and other p...Using the density functional B3P86/cc-PV5Z method, the geometric structure of BH molecule under different external electric fields is optimized, and the bond lengths, dipole moments, vibration frequencies, and other physical properties parameters are obtained. On the basis of setting appropriate parameters, scanning single point energies are obtained by the same method and the potential energy curves under different external fields are also obtained. These results show that the physical property parameters and potential energy curves may change with external electric field, especially in the case of reverse direction electric field. The potential energy function without external electric field is fitted by Morse potential, and the fitting parameters are obtained which are in good agreement with experimental values. In order to obtain the critical dissociation electric parameter, the dipole approximation is adopted to construct a potential model fitting the corresponding potential energy curve of the external electric field. It is found that the fitted critical dissociation electric parameter is consistent with numerical calculation, so that the constructed model is reliable and accurate. These results will provide important theoretical and experimental reference for further studying the molecular spectrum, dynamics, and molecular cooling with Stark effect.展开更多
The theoretical uncertainties of single proton transfer cross sections of the(^(3)He,d)and(d,^(3)He)reactions,owing to the uncertainties of the entrance-and exit-channel optical model potentials,are examined with the^...The theoretical uncertainties of single proton transfer cross sections of the(^(3)He,d)and(d,^(3)He)reactions,owing to the uncertainties of the entrance-and exit-channel optical model potentials,are examined with the^(30)Si(^(3)He,d)^(31)P,^(13)B(d,^(3)He)^(12)Be,and^(34)S(^(3)He,d)^(35)Cl reactions at incident energies of 25,46,and 25 MeV,respectively,within the framework of the distorted wave Born approximation.The differential cross sections at the first peaks in the angular distributions of these reactions are found to have uncertainties of approximately 5%,owing to the uncertainties in the optical model potentials from 20,000 calculations of randomly sampled parameters.This amount of uncertainty is found to be nearly independent of the angular momentum transfer and the target masses within the studied range of incident energies.Uncertainties in the single proton spectroscopic factors obtained by matching the theoretical and experimental cross sections at different scattering angles are also discussed.展开更多
From the mathematical principles, the generalized potential theory can be employed to create constitutive model of geomaterial directly. The similar Cam-clay model, which is created based on the generalized potential ...From the mathematical principles, the generalized potential theory can be employed to create constitutive model of geomaterial directly. The similar Cam-clay model, which is created based on the generalized potential theory, has less assumptions,clearer mathematical basis, and better computational accuracy. Theoretically, it is more scientific than the traditional Cam-clay models. The particle flow code PFC3 D was used to make numerical tests to verify the rationality and practicality of the similar Cam-clay model. The verification process was as follows: 1) creating the soil sample for numerical test in PFC3 D, and then simulating the conventional triaxial compression test, isotropic compression test, and isotropic unloading test by PFC3D; 2)determining the parameters of the similar Cam-clay model from the results of above tests; 3) predicting the sample's behavior in triaxial tests under different stress paths by the similar Cam-clay model, and comparing the predicting results with predictions by the Cam-clay model and the modified Cam-clay model. The analysis results show that the similar Cam-clay model has relatively high prediction accuracy, as well as good practical value.展开更多
A set of new global phenomenological optical model potential parameters has been obtained in the mass range of target nuclei 220≤A≤260 with incident energies below 300 MeV, by simultaneously fitting the experimental...A set of new global phenomenological optical model potential parameters has been obtained in the mass range of target nuclei 220≤A≤260 with incident energies below 300 MeV, by simultaneously fitting the experimental data of 232Th and 23Su, and these potential parameters are analyzed and used to calculate the reaction cross sections, energy spectra and double differ- ential cross sections for p＋232Th reaction. Comparison of calculated results using these potential parameters with available experimental data shows that the present form of global optical model potential could reproduce experimental data for both the neutron and the proton.展开更多
The microscopic global nucleon–nucleus optical model potential(OMP)proposed by Whitehead,Lim,and Holt,the WLH potential(Whitehead et al.,Phys Rev Lett 127:182502,2021),which was constructed in the framework of many-b...The microscopic global nucleon–nucleus optical model potential(OMP)proposed by Whitehead,Lim,and Holt,the WLH potential(Whitehead et al.,Phys Rev Lett 127:182502,2021),which was constructed in the framework of many-body per-turbation theory with state-of-the-art nuclear interactions from chiral effective field theory(EFT),was tested with(p,d)transfer reactions calculated using adiabatic wave approximation.The target nuclei included both stable and unstable nuclei,and the incident energies reached 200 MeV.The results were compared with experimental data and predictions using the phenomenological global optical potential of Koning and Delaroche,the KD02 potential.Overall,we found that the micro-scopic WLH potential described the(p,d)reaction angular distributions similarly to the phenomenological KD02 potential;however,the former was slightly better than the latter for radioactive targets.On average,the obtained spectroscopic factors(SFs)using both microscopic and phenomenological potentials were similar when the incident energies were below approxi-mately 120 MeV.However,their difference tended to increase at higher incident energies,which was particularly apparent for the doubly magic target nucleus 40Ca.展开更多
The astrophysical S-factor of the ^(12)C(p,γ_(0))^(13)N reaction at energies from 25 keV to 5 MeV within the framework of a modified potential cluster model with forbidden states is considered.The experimental phase ...The astrophysical S-factor of the ^(12)C(p,γ_(0))^(13)N reaction at energies from 25 keV to 5 MeV within the framework of a modified potential cluster model with forbidden states is considered.The experimental phase shifts resonant δ_(2)_(S_(1/2)),δ_(2)_(S_(3/2)),and non-resonant δ_(2)_(D_(3/2)) at the energies up to E_(c.m.)=3 MeV are reproduced with high accuracy,which provides the appropriate agreement with the experimental data for the S-factor of 1950-2023 years.Two sets of asymptotic constant are used:Set I refers to C_(w)=1.30(2),and Set II refers to C_(w)=1.37(1).Set I leads to the astrophysical factor S(25)=1.34±0.02 keV-b,which is in agreement with data by Skowronski et al.,2023-1.34±0.09 keV-b;Set II gives S(25)=1.49±0.02 keV-b,which is in agreement with data by Kettner et al.,2023-1.48±0.09 keV-b.The reaction rates of ^(12)C(p,γ_(0))^(13)N at temperatures T_(9) from 0.001 to 10 are calculated.The detailed comparison with some models,the R-matrix approach,and NACRE II data for reaction rates is considered.展开更多
Recently, a condensing potential model was developed to evaluate the crystallization ability of bulk materials [Ye X X, Ming C, Hu Y C and Ning X J 2009 J. Chem. Phys. 130 164711 and Peng K, Ming C, Ye X X, Zhang W X,...Recently, a condensing potential model was developed to evaluate the crystallization ability of bulk materials [Ye X X, Ming C, Hu Y C and Ning X J 2009 J. Chem. Phys. 130 164711 and Peng K, Ming C, Ye X X, Zhang W X, Zhuang J and Ning X J 2011 Chem. Phys. Lett. 501 330], showing that the best temperature for single crystal growth is about0.6Tm, where Tm is the melting temperature, and for Ni–Al alloy, more than 6 wt% of Al-doping will badly reduce the crystallization ability. In order to verify these predictions, we fabricated Ni–Al films with different concentrations of Al on Si substrates at room temperature by pulsed laser deposition, and post-annealed the films at 833, 933, 1033（- 0.6Tm）,1133, and 1233 K in vacuum furnace, respectively. The x-ray diffraction spectra show that annealing at 0.6Tm is indeed best for larger crystal grain formation, and the film crystallization ability remarkably declines with more than 6-wt% Al doping.展开更多
In this paper, we made a new breakthrough, which proposes a new recursion–transform（RT） method with potential parameters to evaluate the nodal potential in arbitrary resistor networks. For the first time, we found ...In this paper, we made a new breakthrough, which proposes a new recursion–transform（RT） method with potential parameters to evaluate the nodal potential in arbitrary resistor networks. For the first time, we found the exact potential formulae of arbitrary m × n cobweb and fan networks by the RT method, and the potential formulae of infinite and semi-infinite networks are derived. As applications, a series of interesting corollaries of potential formulae are given by using the general formula, the equivalent resistance formula is deduced by using the potential formula, and we find a new trigonometric identity by comparing two equivalence results with different forms.展开更多
基金Supported by the National Natural Science Foundation of China （50573063）, the Program for New Century Excellent Talents in University of the State Ministry of Education （NCET-05-0566） and the Specialized Research Fund for the Doctoral Program of Higher Education of China （2005038401）.
文摘A fully flexible potential model for carbon dioxide has been developed to predict the vapor-liquid coexistence properties using the NVT-Gibbs ensemble Monte Carlo technique(GEMC).The average absolute deviation between our simulation and the literature experimental data for saturated liquid and vapor densities is 0.3% and 2.0%,respectively.Compared with the experimental data,our calculated results of critical properties(7.39 MPa,304.04 K,and 0.4679 g?cm-3) are acceptable and are better than those from the rescaling the potential parameters of elementary physical model(EPM2).The agreement of our simulated densities of supercritical carbon dioxide with the experimental data is acceptable in a wide range of pressure and temperature.The radial distribution function estimated at the supercritical conditions suggests that the carbon dioxide is a nonlinear molecule with the C O bond length of 0.117 nm and the O C O bond angle of 176.4°,which are consistent with Car-Parrinello molecular-dynamics(CPMD),whereas the EPM2 model shows large deviation at supercritical state.The predicted self-diffusion coefficients are in agreement with the experiments.
基金Supported by the National Natural Science Foundation of China (No. 29776004) and the National High Performance Computing Center of China for providing the Dawning 1000A computer (No. 99118).
文摘An analytical potential for cylindrical pores has been derived by introducing a variational method into the integration for the calculation of the interaction energy between the wall molecules and a test molecule, all of which are represented by Lennard-Jones potential. The model proposed gives good fit to the results from the cylindrical surface model and the pseudoatom model. To test the potential proposed rigorously, we have carried out grand canonical ensemble Monte Carlo(GCMC) simulation of nitrogen in the MCM-41 pore at 77 K, and compared the simulated adsorption isotherm with the experimental data reported in the literature. The simulated isotherm from our model is in almost qualitative agreement with experiment. Consequently, the model proposed provides an explicit and accurate description of cylindrical pores represented by the Lennard-Jones potential. Moreover, the model can be easily applied to a variety of cylindrical pores, ranging from cylindrical surface to finite thickness walls, in both theoretical studies and computer simulations.
基金Project supported in part by the National Natural Science Foundation of China (Grant No. 62104192)in part by the Natural Science Basic Research Program of Shaanxi Province (Grant No. 2021JQ-717)。
文摘Based on the accurate and efficient thermal injection method, we develop a fully analytical surface potential model for the heterojunction tunnel field-effect transistor(H-TFET). This model accounts for both the effects of source depletion and inversion charge, which are the key factors influencing the charge, capacitance and current in H-TFET. The accuracy of the model is validated against TCAD simulation and is greatly improved in comparison with the conventional model based on Maxwell–Boltzmann approximation. Furthermore, the dependences of the surface potential and electric field on biases are well predicted and thoroughly analyzed.
基金The project supported by National Natural Science Foundation of China under Grant No.10675054
文摘The quark potential model is used to investigate the low-energy elastic scattering of πN system. The model potential consists of the t-channel and s-channel one-gluon exchange potentials and the harmonic oscillator confining potential. By means of the resonating group method, a nonlocal effective potential for the πN system is derived from the interquark potentials and used to calculate the πN elastic scattering phase shifts. By considering the effect of QCD renormalization, the suppression of the spin-orbital coupling and the contribution of the color octet of the clusters （qq） and （qqq）, the numerical results are in fairly good agreement with the experimental data. The same model and method are employed to investigate the possible πN resonances. For this purpose, the resonating group equation is transformed into a standard Schrodinger equation in which the nonlocal effective πN interaction potential is included. Solving the Schrodinger equation by the variational method, we are able to reproduce the masses of some currently concerned πN resonances.
基金Project supported by the National Natural Science Foundation of China （Grant No 10674112） and the Young Teachers Foundation of Northwest Normal University （Grant No NWNU-QN-04-25）.
文摘Using the numerical solution of the time-dependent SchrSdinger equation of a one-dimensional model atom in a two-colour laser field, we have investigated the effects of the potential models on coherent control of atomic multiphoton ionization. It is found that the photoelectron spectra are obviously different for the long-range （Coulomb-like） and short-range （with no excited bound states） potential model atoms, which are produced by two-colour coherent control of atomic multiphoton ionization in a few laser cycles. Our results indicate that two-colour coherent control of atomic multiphoton ionization can be observed in simulations, depending on the choice of the model potentials.
文摘This work conducts a comprehensive analysis of the mass spectra and decay properties of bottomonium states using a relativistic screened potential model. The mass spectrum, decay constants, E 1 transi tions, M 1 transitions, and annihilation decay widths are evaluated. The interpretation of Υ(10355), Υ(10580), Υ(10860), and Υ(11020) a s S-D mixed bottomonium states are analysed. The Υ(10355) state is considered to be 3S-2D,Υ(10580) an d Υ(10753) are consid ered to be 4S-3D mixed states, and the Υ(10860) an d Υ(11020) are considered to be 5S-4D mixed states.
基金supported by the National Natural Science Foundation of China (Grant No.52174065)the National Natural Science Foundation of China (Grant No.52304071)+1 种基金China University of Petroleum,Beijing (Grant No.ZX20220040)MOE Key Laboratory of Petroleum Engineering (China University of Petroleum,No.2462024PTJS002)。
文摘The carbon emissions and cost during the construction phase are significant contributors to the oilfield lifecycle.As oilfields enter the late stage,the adaptability of facilities decreases.To achieve sustainable development,oilfield reconstruction was usually conducted in discrete rather than continuous space.Motivated by economic and sustainability goals,a 3-phase heuristic model for oilfield reconstruction was developed to mine potential locations in continuous space.In phase 1,considering the process characteristics of the oil and gas gathering system,potential locations were mined in continuous space.In phase 2,incorporating comprehensive reconstruction measures,a reconstruction model was established in discrete space.In phase 3,the topology was further adjusted in continuous space.Subsequently,the model was transformed into a single-objective mixed integer linear programming model using the augmented ε-constraint method.Numerical experiments revealed that the small number of potential locations could effectively reduce the reconstruction cost,and the quality of potential locations mined in phase 1 surpassed those generated in random or grid form.Case studies showed that cost and carbon emissions for a new block were reduced by up to 10.45% and 7.21 %,respectively.These reductions were because the potential locations mined in 1P reduced the number of metering stations,and 3P adjusted the locations of metering stations in continuous space to shorten the pipeline length.For an old oilfield,the load and connection ratios of the old metering station increased to 89.7% and 94.9%,respectively,enhancing operation efficiency.Meanwhile,recycling facilitated the diversification of reconstruction measures and yielded a profit of 582,573 ¥,constituting 5.56% of the total cost.This study adopted comprehensive reconstruction measures and tapped into potential reductions in cost and carbon emissions for oilfield reconstruction,offering valuable insights for future oilfield design and construction.
基金Supported by National Natural Science Foundation of China (11175146, 11047023, 11265017)Fundamental Research Funds for Central Universities (XDJK2012D005)
文摘In the QCD-inspired potential model where the quark-antiquark interaction consists of the usual one- gluon-exchange and the mixture of long-range scalar and vector linear confining potentials with the lowest order relativistic correction, we investigate the mass spectra and electromagnetic processes of a bottomonium system by using the Gaussian expansion method. It reveals that the vector component of the mixing confinement is anticonfining and takes around 18.51% of the confining potential. Combining the new experimental data released by Belle, BaBar and LHC, we systematically discuss the energy levels of the bottomouium states and make the predictions of the electromagnetic decays for further experiments.
基金Supported by the National Natural Science Foundation of China(12175100,11975132)the Construct Program of the Key Discipline in Hunan Province+5 种基金the Research Foundation of Education Bureau of Hunan Province,China(18A237)the Natural Science Foundation of Hunan Province,China(2015JJ3103,2018JJ2321)the Innovation Group of Nuclear and Particle Physics in USCthe Shandong Province Natural Science Foundation,China(ZR2019YQ01)Hunan Provincial Innovation Foundation For Postgraduate(CX20210942)the Opening Project of Cooperative Innovation Center for Nuclear Fuel Cycle Technology and Equipment,University of South China(2019KFZ10)。
文摘Considering the preformation probability of the two emitted protons in the parent nucleus,we extend the Coulomb and proximity potential model(CPPM)to systematically study two-proton(2p)radioactivity half-lives of the nuclei close to proton drip line.The proximity potential chosen is Prox.81 proposed by Blocki et al.in 1981.Furthermore,we apply this model to predict the half-lives of possible 2p radioactive candidates whose 2p radioactivity is energetically allowed or observed but not yet quantified in the evaluated nuclear properties table NUBASE2016.The predicted results are in good agreement with those from other theoretical models and empirical formulas,namely the effective liquid drop model(ELDM),generalized liquid drop model(GLDM),Gamow-like model,Sreeja formula and Liu formula.
文摘A simple theoretical equation of state is derived by applying the Tower-Well potential model about the molecular distribution based on the generalized van der Waals partition function. It needs only three molecular parameters which have distinct physical meanings. The resulting equation of state predicts rather well the Vapor pressures, saturate liquid volumes, saturated vapor volumes and PVT thermodynamic properties of polar and structurally complex molecules over a wide temperature and pressure range.
文摘The electrostatic potential energy model of hydrotalcites was based on the theory of crystallography. The anionic potential energy of MgAl-hydrotalcites, with 20 layers and 2107 anions per layer, was calculated, and the anionic stability of the hydrotalcites was investigated. The charge density of the layer and the distance between the adjacent anions varied with the molar ratio of Al^3＋/（Mg^2＋ ＋ Al^3＋）. Anionic potential energy depended on the charge and size of the anions. Calculation results remained consistent with thermal stability and the ion exchange ability reported. This model is able to predict anionic stability of the hydrotalcites.
基金supported by the National Natural Science Foundation of China(Grant No.41875106)the National Key R&D Program of China(Grant No.2016YFA0602401)。
文摘Potential evapotranspiration(EPET)is usually calculated by empirical methods from surface meteorological variables,such as temperature,radiation and wind speed.The in-situ measured pan evaporation(ETpan)can also be used as a proxy for EPET.In this study,EPET values computed from ten models are compared with observed ETpan data in ten Chinese river basins for the period 1961−2013.The daily observed meteorological variables at 2267 stations are used as the input to those models,and a ranking scheme is applied to rank the statistical quantities(ratio of standard deviations,correlation coefficient,and ratio of trends)between ETpan and modeled EPET in different river basins.There are large deviations between the modeled EPET and the ETpan in both the magnitude and the annual trend at most stations.In eight of the basins(except for Southeast and Southwest China),ETpan shows decreasing trends with magnitudes ranging between−0.01 mm d−1 yr−1 and−0.03 mm d−1 yr−1,while the decreasing trends in modeled EPET are less than−0.01 mm d−1 yr−1.Inter comparisons among different models in different river basins suggest that PETHam1 is the best model in the Pearl River basin,PETHam2 outperforms other models in the Huaihe River,Yangtze River and Yellow River basins,and PETFAO is the best model for the remaining basins.Sensitivity analyses reveal that wind speed and sunshine duration are two important factors for decreasing EPET in most basins except in Southeast and Southwest China.The increasing EPET trend in Southeast China is mainly attributed to the reduced relative humidity.
基金Project supported by the National Natural Science Foundation of China(Grand Nos.11147158 and 11264020)the Natural Science Foundation of Jiangxi Province,China(Grand No.2010GQW0031)the Scientific Research Program of the Education Bureau of Jiangxi Province,China(Grand No.GJJ12483)
文摘Using the density functional B3P86/cc-PV5Z method, the geometric structure of BH molecule under different external electric fields is optimized, and the bond lengths, dipole moments, vibration frequencies, and other physical properties parameters are obtained. On the basis of setting appropriate parameters, scanning single point energies are obtained by the same method and the potential energy curves under different external fields are also obtained. These results show that the physical property parameters and potential energy curves may change with external electric field, especially in the case of reverse direction electric field. The potential energy function without external electric field is fitted by Morse potential, and the fitting parameters are obtained which are in good agreement with experimental values. In order to obtain the critical dissociation electric parameter, the dipole approximation is adopted to construct a potential model fitting the corresponding potential energy curve of the external electric field. It is found that the fitted critical dissociation electric parameter is consistent with numerical calculation, so that the constructed model is reliable and accurate. These results will provide important theoretical and experimental reference for further studying the molecular spectrum, dynamics, and molecular cooling with Stark effect.
基金supported by the National Natural Science Foundation of China(No.U2067205).
文摘The theoretical uncertainties of single proton transfer cross sections of the(^(3)He,d)and(d,^(3)He)reactions,owing to the uncertainties of the entrance-and exit-channel optical model potentials,are examined with the^(30)Si(^(3)He,d)^(31)P,^(13)B(d,^(3)He)^(12)Be,and^(34)S(^(3)He,d)^(35)Cl reactions at incident energies of 25,46,and 25 MeV,respectively,within the framework of the distorted wave Born approximation.The differential cross sections at the first peaks in the angular distributions of these reactions are found to have uncertainties of approximately 5%,owing to the uncertainties in the optical model potentials from 20,000 calculations of randomly sampled parameters.This amount of uncertainty is found to be nearly independent of the angular momentum transfer and the target masses within the studied range of incident energies.Uncertainties in the single proton spectroscopic factors obtained by matching the theoretical and experimental cross sections at different scattering angles are also discussed.
基金Projects(51378131,51378403)supported by the National Natural Science Foundation of ChinaProject(2012210020203)supported by the Fundamental Research Funds for the Central Universities,China
文摘From the mathematical principles, the generalized potential theory can be employed to create constitutive model of geomaterial directly. The similar Cam-clay model, which is created based on the generalized potential theory, has less assumptions,clearer mathematical basis, and better computational accuracy. Theoretically, it is more scientific than the traditional Cam-clay models. The particle flow code PFC3 D was used to make numerical tests to verify the rationality and practicality of the similar Cam-clay model. The verification process was as follows: 1) creating the soil sample for numerical test in PFC3 D, and then simulating the conventional triaxial compression test, isotropic compression test, and isotropic unloading test by PFC3D; 2)determining the parameters of the similar Cam-clay model from the results of above tests; 3) predicting the sample's behavior in triaxial tests under different stress paths by the similar Cam-clay model, and comparing the predicting results with predictions by the Cam-clay model and the modified Cam-clay model. The analysis results show that the similar Cam-clay model has relatively high prediction accuracy, as well as good practical value.
基金supported by the China Ministry of Science and Technology (No. 2007CB209903)National Basic Research Program of China(973 Program)
文摘A set of new global phenomenological optical model potential parameters has been obtained in the mass range of target nuclei 220≤A≤260 with incident energies below 300 MeV, by simultaneously fitting the experimental data of 232Th and 23Su, and these potential parameters are analyzed and used to calculate the reaction cross sections, energy spectra and double differ- ential cross sections for p＋232Th reaction. Comparison of calculated results using these potential parameters with available experimental data shows that the present form of global optical model potential could reproduce experimental data for both the neutron and the proton.
基金Supported by National Natural Science Foundation of China(Nos.U2067205 and 12205098)National Key Laboratory of Computational Physics(HX02021-35).
文摘The microscopic global nucleon–nucleus optical model potential(OMP)proposed by Whitehead,Lim,and Holt,the WLH potential(Whitehead et al.,Phys Rev Lett 127:182502,2021),which was constructed in the framework of many-body per-turbation theory with state-of-the-art nuclear interactions from chiral effective field theory(EFT),was tested with(p,d)transfer reactions calculated using adiabatic wave approximation.The target nuclei included both stable and unstable nuclei,and the incident energies reached 200 MeV.The results were compared with experimental data and predictions using the phenomenological global optical potential of Koning and Delaroche,the KD02 potential.Overall,we found that the micro-scopic WLH potential described the(p,d)reaction angular distributions similarly to the phenomenological KD02 potential;however,the former was slightly better than the latter for radioactive targets.On average,the obtained spectroscopic factors(SFs)using both microscopic and phenomenological potentials were similar when the incident energies were below approxi-mately 120 MeV.However,their difference tended to increase at higher incident energies,which was particularly apparent for the doubly magic target nucleus 40Ca.
基金Carried out within Project No.AP19676483«Study of hydrogen thermonuclear fusion processes in the CNO cycle in the Sun and in stars»,supported by the Ministry of Science and Higher Education of the Republic of Kazakhstan.
文摘The astrophysical S-factor of the ^(12)C(p,γ_(0))^(13)N reaction at energies from 25 keV to 5 MeV within the framework of a modified potential cluster model with forbidden states is considered.The experimental phase shifts resonant δ_(2)_(S_(1/2)),δ_(2)_(S_(3/2)),and non-resonant δ_(2)_(D_(3/2)) at the energies up to E_(c.m.)=3 MeV are reproduced with high accuracy,which provides the appropriate agreement with the experimental data for the S-factor of 1950-2023 years.Two sets of asymptotic constant are used:Set I refers to C_(w)=1.30(2),and Set II refers to C_(w)=1.37(1).Set I leads to the astrophysical factor S(25)=1.34±0.02 keV-b,which is in agreement with data by Skowronski et al.,2023-1.34±0.09 keV-b;Set II gives S(25)=1.49±0.02 keV-b,which is in agreement with data by Kettner et al.,2023-1.48±0.09 keV-b.The reaction rates of ^(12)C(p,γ_(0))^(13)N at temperatures T_(9) from 0.001 to 10 are calculated.The detailed comparison with some models,the R-matrix approach,and NACRE II data for reaction rates is considered.
基金Project supported by the Specialized Research Fund for the Doctoral Program of Higher EducationChina(Grant No.20130071110018)the National Natural Science Foundation of China(Grant No.11274073)
文摘Recently, a condensing potential model was developed to evaluate the crystallization ability of bulk materials [Ye X X, Ming C, Hu Y C and Ning X J 2009 J. Chem. Phys. 130 164711 and Peng K, Ming C, Ye X X, Zhang W X, Zhuang J and Ning X J 2011 Chem. Phys. Lett. 501 330], showing that the best temperature for single crystal growth is about0.6Tm, where Tm is the melting temperature, and for Ni–Al alloy, more than 6 wt% of Al-doping will badly reduce the crystallization ability. In order to verify these predictions, we fabricated Ni–Al films with different concentrations of Al on Si substrates at room temperature by pulsed laser deposition, and post-annealed the films at 833, 933, 1033（- 0.6Tm）,1133, and 1233 K in vacuum furnace, respectively. The x-ray diffraction spectra show that annealing at 0.6Tm is indeed best for larger crystal grain formation, and the film crystallization ability remarkably declines with more than 6-wt% Al doping.
基金Project supported by the Natural Science Foundation of Jiangsu Province,China(Grant No.BK20161278)
文摘In this paper, we made a new breakthrough, which proposes a new recursion–transform（RT） method with potential parameters to evaluate the nodal potential in arbitrary resistor networks. For the first time, we found the exact potential formulae of arbitrary m × n cobweb and fan networks by the RT method, and the potential formulae of infinite and semi-infinite networks are derived. As applications, a series of interesting corollaries of potential formulae are given by using the general formula, the equivalent resistance formula is deduced by using the potential formula, and we find a new trigonometric identity by comparing two equivalence results with different forms.
