Jarzynski' identity (JI) method was suggested a promising tool for reconstructing free energy landscape of biomolecular interactions in numerical simulations and ex- periments. However, JI method has not yet been w...Jarzynski' identity (JI) method was suggested a promising tool for reconstructing free energy landscape of biomolecular interactions in numerical simulations and ex- periments. However, JI method has not yet been well tested in complex systems such as ligand-receptor molecular pairs. In this paper, we applied a huge number of steered molec- ular dynamics (SMD) simulations to dissociate the protease of human immunodeficiency type I virus (HIV-1 protease) and its inhibitors. We showed that because of intrinsic com- plexity of the ligand-receptor system, the energy barrier pre- dicted by JI method at high pulling rates is much higher than experimental results. However, with a slower pulling rate and fewer switch times of simulations, the predictions of JI method can approach to the experiments. These results sug- gested that the JI method is more appropriate for reconstruct- ing free energy landscape using the data taken from experi- ments, since the pulling rates used in experiments are often much slower than those in SMD simulations. Furthermore, we showed that a higher loading stiffness can produce higher precision of calculation of energy landscape because it yields a lower mean value and narrower bandwidth of work distri- bution in SMD simulations.展开更多
Anodic oxidation on pure titanium(α-Ti) surface causes the formation ofinterferential films with different colours,mainly golden,pink and blue.The col-our changes with the thickness of the ox-ide film.One of the fact...Anodic oxidation on pure titanium(α-Ti) surface causes the formation ofinterferential films with different colours,mainly golden,pink and blue.The col-our changes with the thickness of the ox-ide film.One of the factors,which influ-ences the growth rate of the film,may bethe grain surface energy.at least at the展开更多
On the basis of the-improved self-exchange model of reorganization phenomenon and accurate potential functions from ab initio calculation at HFSCF 6-31G* and DZP levels a new calculation method was,presented for the i...On the basis of the-improved self-exchange model of reorganization phenomenon and accurate potential functions from ab initio calculation at HFSCF 6-31G* and DZP levels a new calculation method was,presented for the inner-sphere reorganization energy, values for diatomic molecular redox couples in gas phase electron transfer process have been calculated. Results agree well with the experimental data, and the effectiveness and importance of this method have been demonstrated for calculation of inner-sphere reorganization energy in gas phase electron transfer process.展开更多
Neutral particle energy spectra in the HT-7 tokamak are calculated by using the Monte Carlo method. It can reproduce the spectra measured in experiment. Differences of neutral particle energy spectra in higher and low...Neutral particle energy spectra in the HT-7 tokamak are calculated by using the Monte Carlo method. It can reproduce the spectra measured in experiment. Differences of neutral particle energy spectra in higher and lower electron density plasma are discussed. Results show that the ion temperature given by neutral particle energy spectra is lower than the real ion temperature, but the deviation is within 10% if the ion temperature is less than 800 eV and thecentral chord-averaged electron density does not exceed 3 ×1013 cm-3. But for ion temperature higher than 1000 eV at the central chord-averaged density limit up to 5 ×1013 cm-3, the neutral particle energy spectra can still give the ion temperature within 10% deviation.展开更多
Carboxyltransferase domain(CT) of acetyl-coenzyme A carboxylase(ACCase, EC 6.4.1.2) from a family of Poaceae is an important target of commercial herbicide APPs for controlling grass weed growth. As the abuse of A...Carboxyltransferase domain(CT) of acetyl-coenzyme A carboxylase(ACCase, EC 6.4.1.2) from a family of Poaceae is an important target of commercial herbicide APPs for controlling grass weed growth. As the abuse of APPs herbicides, the resistant ACCase due to the mutation of a single residue(Ile→Leu), which is located in CT active site, is emergent in many populations and species of Poaceae. So it is urgent to understand the resistant mechanism so as to design new effect herbicides. Herein lies the complex of CT dimmer from Lolium rigidum and herbicide haloxyfop successfully constructed for wild type enzyme and Ile/Leu mutant, respectively, providing a basis for explaining the resistance from microscopic structure. Moreover, the binding free energy difference between wild type and mutant enzymes was predicted in good agreement with the known observation, and the various contributions to it were analyzed, by Molecular mechanics-Poisson-Boltzmann surface area(MM-PBSA) method. The results indicate the van der Waals interaction difference between the protein and inhibitor, -22.94 kJ/mol of CT wild type lower than that of mutant, is the major reason for resistance. Structure analysis further suggests that van der Waals interaction difference is originated from the steric hindrance between the side chain of mutated residue Leu and the chiral methyl group of haloxyfop. All these findings enhance the understanding of resistant mechanism of ACCase to herbicide by Ile/Leu mutation and provide an important clue for the rational design of high effective herbicides.展开更多
The possible inclusion modes of berberine(Berb) with β-cyclodextrin(BCD) in aqueous solution were predicted by molecular docking,molecular dynamics(MD) simulation and binding free energy calculations.Firstly,th...The possible inclusion modes of berberine(Berb) with β-cyclodextrin(BCD) in aqueous solution were predicted by molecular docking,molecular dynamics(MD) simulation and binding free energy calculations.Firstly,the molecular docking result reveals that the docking conformations of Berb appeared in two clusters ranked in two opposite orientations.Then,10 ns MD simulation was performed separately on the lowest energy conformation of each orientation(Mode I and Mode II) obtained by molecular docking.Moreover,based on the trajectories from MD simulation,the binding free energies of the two different modes were calculated by the Molecular Mechanics/Poisson Boltzmann surface area(MM/PBSA) method.Through analyzing the binding free energies of Berb with BCD,we found that Mode II was the preferential inclusion mode,which was in good agreement with the experimental result.In addition,the computed results show that the main impetus for the complex was the van der Waals interaction,but the solvation energy and the entropy change produced an adverse effect on the complex.展开更多
An open-framework gallophosphate, Ga_9(PO_4)_ 12[(H_3TREN)(H_2TREN)_3]·xH_2O was hydrothermally synthesized at 453 K with tris(2-aminoethyl) amine(TREN) as the organic template and characterized by single-crysta...An open-framework gallophosphate, Ga_9(PO_4)_ 12[(H_3TREN)(H_2TREN)_3]·xH_2O was hydrothermally synthesized at 453 K with tris(2-aminoethyl) amine(TREN) as the organic template and characterized by single-crystal X-ray diffraction. Ga_9(PO_4)_ 12[(H_3TREN)(H_2TREN)_3]·xH_2O crystallized in a cubic space group I43m, with a=1.68552(3) nm and Z=2. The structure contains 12-membered ring channels and supercages of 1.434 nm in diameter, and is an analogue of Al_9(PO_4)_ 12(C_ 24H_ 91N_ 16)·17H_2O. Template-TREN in the supercage was different from triethylenetetraamine(TETA) used in the initial reaction mixture due to the construction transformation. The TETAs transformed into the TRENs due to the low interaction energy between the template and framework. We verified it via energy calculation and liquid state NMR.展开更多
It has remained an open problem to accurately compute the partition function of macroscopic systems since the establishment of statistical physics. A rapid method approaching this problem was presented and was strictl...It has remained an open problem to accurately compute the partition function of macroscopic systems since the establishment of statistical physics. A rapid method approaching this problem was presented and was strictly tested by molecular dynamic (MD) simulations on Ar atoms in both dense gaseous and liquid states. The outcomes from the method on the internal energy and the work of isothermal expansion (and therefore the free energy) are in good agreement with the MD simulations, suggesting the method would be immediately applied in vast areas.展开更多
The accurate dissociation energy and equilibrium geometry of the ball state of ^7LiH molecule is calculated using a symmetry-adapted-cluster configuration-interaction method in full active space. And the calculated re...The accurate dissociation energy and equilibrium geometry of the ball state of ^7LiH molecule is calculated using a symmetry-adapted-cluster configuration-interaction method in full active space. And the calculated results are 0.2580 eV and 0.1958 nm for the dissociation energy and equilibrium geometry, respectively. The whole potential energy curve for the b^3∏ state is also calculated over the internuclear separation range from about 0.10 to 0.54 nm. The results are fitted by the Murrell-Sorbie function. It is found that the Murrell-Sorbie function form, which is mainly used to fit the ground-state potential energy function, is well suitable for the excited triplet b^3∏ state. The vertical excitation energy from the ground state to the b^3∏ state is calculated to be 4.233 eV. Based on the analytic potential energy function, the harmonic frequency of 610.88 cm^-1 about this state is firstly estimated. Compared with other theoretical results, this work is the most complete effort to deal with the analytic potential energy function and the harmonic frequency of this state.展开更多
This paper deals with the hydrodynamic response to waves of a 3-D OWC(oscillating water column)wave energy absorber with converging channel.The theoretical solutions are presented by means of three-dimensional GREEN f...This paper deals with the hydrodynamic response to waves of a 3-D OWC(oscillating water column)wave energy absorber with converging channel.The theoretical solutions are presented by means of three-dimensional GREEN function method.In the calculation,the flow field is divided into two subregions:an inside field and an outside one.In the outside field the solution is represented by oscillating sources distributed on the outer surface of the chamber of the absorber,while the solution of the inside field is expressed by Rakine source-distribution on the inner surface of the chamber.Both solutions are matched on the artificial interface.The calculated.values seem to agree reasonably well with experimental results.展开更多
To research the correlation between vibrational energy transition rates and acoustic relaxation processes in excitable gases, the vibrational relaxation theory provided by Tanczos [J. Chem. Phy3. 25, 439 (1956)] is ...To research the correlation between vibrational energy transition rates and acoustic relaxation processes in excitable gases, the vibrational relaxation theory provided by Tanczos [J. Chem. Phy3. 25, 439 (1956)] is applied to calculate the energy transition rates of Vibrational- Vibrational (V-V) and Vibrational-Translational (V-T) energy transfer in gas mixtures. The results of calculation for the multi-relaxation processes in various gas mixtures, consisting of carbon dioxide, methane, chlorine, nitrogen, and oxygen at room temperature, demonstrate that the acoustic energy stagnated in every vibrational mode is coupled with each other through V-V energy exchanges. The vibrational excitation energy will relax through the V-T de-excitation path of the lowest mode because of its fastest V-T transition rate, resulting in that only one absorption peak can be measured for most of excitable gas mixtures. Thus, an effective model is provided to analyze how the vibrational energy transition rates affect the characteristics of acoustic relaxation processes and acoustic propagation in excitable gas mixtures.展开更多
This work brings all new and advanced technology which is proposed for refinement and improvement in the existing electrification system at domestic as well as commercial levels including hotels, commercial complexes,...This work brings all new and advanced technology which is proposed for refinement and improvement in the existing electrification system at domestic as well as commercial levels including hotels, commercial complexes, apartments, rented floors and rooms. This advanced module will not only convey means of luxury but will also accomplish real-time energy monitoring and cost es-timation. This developed module will rule out entire re-wiring and will be fruitful at places where installation of a new meter was a problem. The new system after installation will offer means of comfort to the consumer, elderly as well as handicapped and disabled people in operating electric load with ease and comfort. Apart from this, it would also benefit the apartment/hotel owner’s and business personnel who have rented their property or portion of property and face problems in calculating energy bill.展开更多
Based on the ab initio/6-31Gcalculation, the potential barrier to internal rotation in mol-ecule HN--BHhas been studed by means of PD/LSF atomic charge model and Buckingham(exp--6-1)energy partition method. The resu...Based on the ab initio/6-31Gcalculation, the potential barrier to internal rotation in mol-ecule HN--BHhas been studed by means of PD/LSF atomic charge model and Buckingham(exp--6-1)energy partition method. The results indicate that the order of the contributions of the componentsto the total energy barrier △E is |△V|(electrostatic) >|△V| (charge transfer)>|△V| (exchangerepulsion)>|△V| (dispersion). For △Vthere are maxima at θ= 30°and 90°, and a saddle atθ= 60°. There are good linear relationships for the total barrier △E, △Vand △Vwith cos3θrespectively, and the same for the dipole moment from PD/LSF model (μ) and that from abinitio calculation (μ) vs. cos3θ respectively.展开更多
In the first step the extremal values of the vibrational specific heat and entropy represented by the Planck oscillators at the low temperatures could be calculated. The positions of the extrema are defined by the dim...In the first step the extremal values of the vibrational specific heat and entropy represented by the Planck oscillators at the low temperatures could be calculated. The positions of the extrema are defined by the dimensionless ratios between the quanta of the vibrational energy and products of the actual temperature multiplied by the Boltzmann constant. It became evident that position of a local maximum obtained for the Planck’s average energy of a vibration mode and position of a local maximum of entropy are the same. In the next step the Haken’s time-dependent perturbation approach to the pair of quantum non-degenerate Schr<span style="white-space:nowrap;">?</span>dinger eigenstates of energy is re-examined. An averaging process done on the time variable leads to a very simple formula for the coefficients entering the perturbation terms.展开更多
For leader-following networked systems with the topology switching and the aperiodic silence,limited-energy output formation tracking problems are investigated.Firstly,a new output formation tracking control protocol ...For leader-following networked systems with the topology switching and the aperiodic silence,limited-energy output formation tracking problems are investigated.Firstly,a new output formation tracking control protocol is proposed,which contains two components associated with the communication interactions between the leader and tracking intelligent agents and the communication interactions among tracking intelligent agents,respectively,and the aperiodic silence,the topology switching and the energy constraint index is introduced properly.Then,a two-step transformation method is presented to separate the whole dynamics of a networked system into the relative dynamics between the leader and tracking intelligent agents and the dynamics of the leader,and sufficient conditions for limited-energy output formation tracking for networked systems with limited energy and aperiodic silence are presented,which are extended into networked systems without the aperiodic silence.Especially,a partition checking algorithm is presented to check limitedenergy output formation tracking design criteria.Finally,a numerical example is illustrated to demonstrate the validness of theoretical results.展开更多
By using potential energy surface(PES)calculations in the three-dimensional space(β_(2),γ,β_(4))within the framework of the macroscopic-microscopic model,the fission trajectory and fission barrier for Z=118(Og),119...By using potential energy surface(PES)calculations in the three-dimensional space(β_(2),γ,β_(4))within the framework of the macroscopic-microscopic model,the fission trajectory and fission barrier for Z=118(Og),119,120 nuclei has been systematically investigated.The calculated PES includes macroscopic liquid-drop energy,microscopic shell correction and pairing correction.Taking the ^(294)Og176 nucleus as an example,we discuss the next closed shell after Z=82 and N=126 with the calculated Woods-Saxon single-particle levels.Then,the results of PES in ^(294)Og is illustrated from the(X,Y)scale to the(β_(2),γ)scale.Theγdegree of freedom reveals the shape evolution clearly during the fission process.The structure near the minimum and saddle point of the PES in the Z=118,119,120 nuclei is demonstrated simultaneously.Based on the potential energy curves,general trends of the evolution of the fission barrier heights and widths are also studied.The triaxial deformation in these superheavy mass regions plays a vital role in the first fission barrier,showing a significant reduction in both triaxial paths.In addition,the model-dependent fission barriers of proton-rich nuclei ^(295)Og,296119,and 297120 are analyzed briefly.Our studies could be valuable for synthesizing the superheavy new elements in the forthcoming HIAF and other facilities.展开更多
Integrated energy systems(IES)are under development to accommodate the widespread penetration of renewable energy into power systems.The universal utilization of coupling components makes the connection between power ...Integrated energy systems(IES)are under development to accommodate the widespread penetration of renewable energy into power systems.The universal utilization of coupling components makes the connection between power grids and heat grids even closer.This paper applies energy flow calculations to planning problems and explores a method for selecting coupling components in the integrated electrical and heating systems.This process is based on the analysis of energy flow distribution and the comprehensive indexes,which include operation cost and the penalty cost of wind curtailment and solar energy curtailment.Besides,a selection method of coupling components installation locations based on energy flow calculations is provided.At last,an IES with 5 electrical buses and 5 heating nodes,and a 9-bus electrical power system with a 31-node heating transmission system are chosen to study the specific application problems in detail as well as to elucidate the effectiveness of the proposed method.It turned out that the relevant coupling components and their positions can be selected according to the indexes obtained by integrated electrical-hydraulic-thermal calculation.This proposed method is conducive to the planning of integrated energy systems.展开更多
Many molecular events are associated with small or large conformational changes occurring in the corresponding proteins.Modeling such changes is a challenge and requires significant amount of computing time.From point...Many molecular events are associated with small or large conformational changes occurring in the corresponding proteins.Modeling such changes is a challenge and requires significant amount of computing time.From point of view of electrostatics,these changes can be viewed as a reorganization of local charges and dipoles in response to the changes of the electrostatic field,if the cause is insertion or deletion of a charged amino acid.Here we report a large scale investigation of modeling the changes of the folding energy due to single mutations involving charged group.This allows the changes of the folding energy to be considered mostly electrostatics in origin and to be calculated with DelPhi assigning residue-specific value of the internal dielectric constant of protein.The predicted energy changes are benchmarked against experimentally measured changes of the folding energy on a set of 257 single mutations.The best fit between experimental values and predicted changes is used to find out the effective value of the internal dielectric constant for each type of amino acid.The predicted folding free energy changes with the optimal,amino acid specific,dielectric constants are within RMSD=0.86 kcal/mol from experimentally measured changes.展开更多
We propose and test a new method of estimating the model parameters of the phenomenological BetheWeizsacker mass formula.Based on the Monte Carlo sampling of a large dataset,we obtain,for the first time,a Cauchy-type ...We propose and test a new method of estimating the model parameters of the phenomenological BetheWeizsacker mass formula.Based on the Monte Carlo sampling of a large dataset,we obtain,for the first time,a Cauchy-type parameter distribution formed by the exact solutions of linear equation systems.Using the maximum likelihood estimation,the location and scale parameters are evaluated.The estimated results are compared with those obtained by solving overdetermined systems,e.g.,the solutions of the traditional least-squares method.Parameter correlations and uncertainty propagation are briefly discussed.As expected,it is also found that improvements in theoretical modeling(e.g.,considering microscopic corrections)decrease the parameter and propagation uncertainties.展开更多
基金supported by the National Science Foundation of China (10732050,10872115 and 11025208)Excellent Young Scholars Research Fund of Beijing Institute of Technology
文摘Jarzynski' identity (JI) method was suggested a promising tool for reconstructing free energy landscape of biomolecular interactions in numerical simulations and ex- periments. However, JI method has not yet been well tested in complex systems such as ligand-receptor molecular pairs. In this paper, we applied a huge number of steered molec- ular dynamics (SMD) simulations to dissociate the protease of human immunodeficiency type I virus (HIV-1 protease) and its inhibitors. We showed that because of intrinsic com- plexity of the ligand-receptor system, the energy barrier pre- dicted by JI method at high pulling rates is much higher than experimental results. However, with a slower pulling rate and fewer switch times of simulations, the predictions of JI method can approach to the experiments. These results sug- gested that the JI method is more appropriate for reconstruct- ing free energy landscape using the data taken from experi- ments, since the pulling rates used in experiments are often much slower than those in SMD simulations. Furthermore, we showed that a higher loading stiffness can produce higher precision of calculation of energy landscape because it yields a lower mean value and narrower bandwidth of work distri- bution in SMD simulations.
文摘Anodic oxidation on pure titanium(α-Ti) surface causes the formation ofinterferential films with different colours,mainly golden,pink and blue.The col-our changes with the thickness of the ox-ide film.One of the factors,which influ-ences the growth rate of the film,may bethe grain surface energy.at least at the
文摘On the basis of the-improved self-exchange model of reorganization phenomenon and accurate potential functions from ab initio calculation at HFSCF 6-31G* and DZP levels a new calculation method was,presented for the inner-sphere reorganization energy, values for diatomic molecular redox couples in gas phase electron transfer process have been calculated. Results agree well with the experimental data, and the effectiveness and importance of this method have been demonstrated for calculation of inner-sphere reorganization energy in gas phase electron transfer process.
文摘Neutral particle energy spectra in the HT-7 tokamak are calculated by using the Monte Carlo method. It can reproduce the spectra measured in experiment. Differences of neutral particle energy spectra in higher and lower electron density plasma are discussed. Results show that the ion temperature given by neutral particle energy spectra is lower than the real ion temperature, but the deviation is within 10% if the ion temperature is less than 800 eV and thecentral chord-averaged electron density does not exceed 3 ×1013 cm-3. But for ion temperature higher than 1000 eV at the central chord-averaged density limit up to 5 ×1013 cm-3, the neutral particle energy spectra can still give the ion temperature within 10% deviation.
基金Supported by the National Natural Science Foundation of China(Nos.20802025, 30870539, 20432010 and 20672045)
文摘Carboxyltransferase domain(CT) of acetyl-coenzyme A carboxylase(ACCase, EC 6.4.1.2) from a family of Poaceae is an important target of commercial herbicide APPs for controlling grass weed growth. As the abuse of APPs herbicides, the resistant ACCase due to the mutation of a single residue(Ile→Leu), which is located in CT active site, is emergent in many populations and species of Poaceae. So it is urgent to understand the resistant mechanism so as to design new effect herbicides. Herein lies the complex of CT dimmer from Lolium rigidum and herbicide haloxyfop successfully constructed for wild type enzyme and Ile/Leu mutant, respectively, providing a basis for explaining the resistance from microscopic structure. Moreover, the binding free energy difference between wild type and mutant enzymes was predicted in good agreement with the known observation, and the various contributions to it were analyzed, by Molecular mechanics-Poisson-Boltzmann surface area(MM-PBSA) method. The results indicate the van der Waals interaction difference between the protein and inhibitor, -22.94 kJ/mol of CT wild type lower than that of mutant, is the major reason for resistance. Structure analysis further suggests that van der Waals interaction difference is originated from the steric hindrance between the side chain of mutated residue Leu and the chiral methyl group of haloxyfop. All these findings enhance the understanding of resistant mechanism of ACCase to herbicide by Ile/Leu mutation and provide an important clue for the rational design of high effective herbicides.
基金Supported by the National Natural Science Foundation of China(No. 20975081)the Open Foundation of the Key Laboratory of Synthetic and Natural Functional Molecular Chemistry of Ministry of Education,China(No.KF09014)the Northwest University Graduate Cross-discipline Funds,China(No.09YJC18)
文摘The possible inclusion modes of berberine(Berb) with β-cyclodextrin(BCD) in aqueous solution were predicted by molecular docking,molecular dynamics(MD) simulation and binding free energy calculations.Firstly,the molecular docking result reveals that the docking conformations of Berb appeared in two clusters ranked in two opposite orientations.Then,10 ns MD simulation was performed separately on the lowest energy conformation of each orientation(Mode I and Mode II) obtained by molecular docking.Moreover,based on the trajectories from MD simulation,the binding free energies of the two different modes were calculated by the Molecular Mechanics/Poisson Boltzmann surface area(MM/PBSA) method.Through analyzing the binding free energies of Berb with BCD,we found that Mode II was the preferential inclusion mode,which was in good agreement with the experimental result.In addition,the computed results show that the main impetus for the complex was the van der Waals interaction,but the solvation energy and the entropy change produced an adverse effect on the complex.
文摘An open-framework gallophosphate, Ga_9(PO_4)_ 12[(H_3TREN)(H_2TREN)_3]·xH_2O was hydrothermally synthesized at 453 K with tris(2-aminoethyl) amine(TREN) as the organic template and characterized by single-crystal X-ray diffraction. Ga_9(PO_4)_ 12[(H_3TREN)(H_2TREN)_3]·xH_2O crystallized in a cubic space group I43m, with a=1.68552(3) nm and Z=2. The structure contains 12-membered ring channels and supercages of 1.434 nm in diameter, and is an analogue of Al_9(PO_4)_ 12(C_ 24H_ 91N_ 16)·17H_2O. Template-TREN in the supercage was different from triethylenetetraamine(TETA) used in the initial reaction mixture due to the construction transformation. The TETAs transformed into the TRENs due to the low interaction energy between the template and framework. We verified it via energy calculation and liquid state NMR.
基金Project supported by the Specialized Research Fund for the Doctoral Program of Higher Education,China(Grant No.20130071110018)the National Natural Science Foundation of China(Grant No.11274073)
文摘It has remained an open problem to accurately compute the partition function of macroscopic systems since the establishment of statistical physics. A rapid method approaching this problem was presented and was strictly tested by molecular dynamic (MD) simulations on Ar atoms in both dense gaseous and liquid states. The outcomes from the method on the internal energy and the work of isothermal expansion (and therefore the free energy) are in good agreement with the MD simulations, suggesting the method would be immediately applied in vast areas.
基金This work was supported by the National Natural Science Foundation of China (No. 10574039)Henan Innovation Fund for University Prominent Research Talents (No. 2006KYCX002).
文摘The accurate dissociation energy and equilibrium geometry of the ball state of ^7LiH molecule is calculated using a symmetry-adapted-cluster configuration-interaction method in full active space. And the calculated results are 0.2580 eV and 0.1958 nm for the dissociation energy and equilibrium geometry, respectively. The whole potential energy curve for the b^3∏ state is also calculated over the internuclear separation range from about 0.10 to 0.54 nm. The results are fitted by the Murrell-Sorbie function. It is found that the Murrell-Sorbie function form, which is mainly used to fit the ground-state potential energy function, is well suitable for the excited triplet b^3∏ state. The vertical excitation energy from the ground state to the b^3∏ state is calculated to be 4.233 eV. Based on the analytic potential energy function, the harmonic frequency of 610.88 cm^-1 about this state is firstly estimated. Compared with other theoretical results, this work is the most complete effort to deal with the analytic potential energy function and the harmonic frequency of this state.
文摘This paper deals with the hydrodynamic response to waves of a 3-D OWC(oscillating water column)wave energy absorber with converging channel.The theoretical solutions are presented by means of three-dimensional GREEN function method.In the calculation,the flow field is divided into two subregions:an inside field and an outside one.In the outside field the solution is represented by oscillating sources distributed on the outer surface of the chamber of the absorber,while the solution of the inside field is expressed by Rakine source-distribution on the inner surface of the chamber.Both solutions are matched on the artificial interface.The calculated.values seem to agree reasonably well with experimental results.
基金supported by the National Natural Science Foundation of China(61461008,61371139,61571201,61540051)the China Scholarship Council Project(201708525058)+1 种基金the National Science Foundation of Guizhou Province,China(Qian Ke He J Zi[2015]2065),Qian Ke He LH Zi[2014]7361)the Recruitment Program of Guizhou Institute of Technology(XJGC20140601,XJGC20150107)
文摘To research the correlation between vibrational energy transition rates and acoustic relaxation processes in excitable gases, the vibrational relaxation theory provided by Tanczos [J. Chem. Phy3. 25, 439 (1956)] is applied to calculate the energy transition rates of Vibrational- Vibrational (V-V) and Vibrational-Translational (V-T) energy transfer in gas mixtures. The results of calculation for the multi-relaxation processes in various gas mixtures, consisting of carbon dioxide, methane, chlorine, nitrogen, and oxygen at room temperature, demonstrate that the acoustic energy stagnated in every vibrational mode is coupled with each other through V-V energy exchanges. The vibrational excitation energy will relax through the V-T de-excitation path of the lowest mode because of its fastest V-T transition rate, resulting in that only one absorption peak can be measured for most of excitable gas mixtures. Thus, an effective model is provided to analyze how the vibrational energy transition rates affect the characteristics of acoustic relaxation processes and acoustic propagation in excitable gas mixtures.
文摘This work brings all new and advanced technology which is proposed for refinement and improvement in the existing electrification system at domestic as well as commercial levels including hotels, commercial complexes, apartments, rented floors and rooms. This advanced module will not only convey means of luxury but will also accomplish real-time energy monitoring and cost es-timation. This developed module will rule out entire re-wiring and will be fruitful at places where installation of a new meter was a problem. The new system after installation will offer means of comfort to the consumer, elderly as well as handicapped and disabled people in operating electric load with ease and comfort. Apart from this, it would also benefit the apartment/hotel owner’s and business personnel who have rented their property or portion of property and face problems in calculating energy bill.
基金the National Natural Science Foundation of China.
文摘Based on the ab initio/6-31Gcalculation, the potential barrier to internal rotation in mol-ecule HN--BHhas been studed by means of PD/LSF atomic charge model and Buckingham(exp--6-1)energy partition method. The results indicate that the order of the contributions of the componentsto the total energy barrier △E is |△V|(electrostatic) >|△V| (charge transfer)>|△V| (exchangerepulsion)>|△V| (dispersion). For △Vthere are maxima at θ= 30°and 90°, and a saddle atθ= 60°. There are good linear relationships for the total barrier △E, △Vand △Vwith cos3θrespectively, and the same for the dipole moment from PD/LSF model (μ) and that from abinitio calculation (μ) vs. cos3θ respectively.
文摘In the first step the extremal values of the vibrational specific heat and entropy represented by the Planck oscillators at the low temperatures could be calculated. The positions of the extrema are defined by the dimensionless ratios between the quanta of the vibrational energy and products of the actual temperature multiplied by the Boltzmann constant. It became evident that position of a local maximum obtained for the Planck’s average energy of a vibration mode and position of a local maximum of entropy are the same. In the next step the Haken’s time-dependent perturbation approach to the pair of quantum non-degenerate Schr<span style="white-space:nowrap;">?</span>dinger eigenstates of energy is re-examined. An averaging process done on the time variable leads to a very simple formula for the coefficients entering the perturbation terms.
基金supported by the National Natural Science Foundation of China(Nos.62176263,62103434,62003363,61867005,61703411)the Science and Technology Nova Plan of Beijing,China(No.Z201100006820122)+4 种基金the Shaanxi Natural Science Foundation for Distinguished Young Scholars,China(No.2021JC-35)the Shaanxi Natural Science Foundation for Youths,China(No.2021JQ-375)China Postdoctoral Science Special Foundation(No.2021T140790)China Postdoctoral Research Foundation of China(No.271004)the Gansu Provincial First-Class Discipline Program of Northwest Minzu University,China(No.11080305)。
文摘For leader-following networked systems with the topology switching and the aperiodic silence,limited-energy output formation tracking problems are investigated.Firstly,a new output formation tracking control protocol is proposed,which contains two components associated with the communication interactions between the leader and tracking intelligent agents and the communication interactions among tracking intelligent agents,respectively,and the aperiodic silence,the topology switching and the energy constraint index is introduced properly.Then,a two-step transformation method is presented to separate the whole dynamics of a networked system into the relative dynamics between the leader and tracking intelligent agents and the dynamics of the leader,and sufficient conditions for limited-energy output formation tracking for networked systems with limited energy and aperiodic silence are presented,which are extended into networked systems without the aperiodic silence.Especially,a partition checking algorithm is presented to check limitedenergy output formation tracking design criteria.Finally,a numerical example is illustrated to demonstrate the validness of theoretical results.
基金Supported by the National Natural Science Foundation of China(Grant Nos.12205076 and 12047504)the China Postdoctoral Science Foundation(Grant No.2020M670012)the Launching Fund of Henan University of Technology(Grant No.2021BS047).
文摘By using potential energy surface(PES)calculations in the three-dimensional space(β_(2),γ,β_(4))within the framework of the macroscopic-microscopic model,the fission trajectory and fission barrier for Z=118(Og),119,120 nuclei has been systematically investigated.The calculated PES includes macroscopic liquid-drop energy,microscopic shell correction and pairing correction.Taking the ^(294)Og176 nucleus as an example,we discuss the next closed shell after Z=82 and N=126 with the calculated Woods-Saxon single-particle levels.Then,the results of PES in ^(294)Og is illustrated from the(X,Y)scale to the(β_(2),γ)scale.Theγdegree of freedom reveals the shape evolution clearly during the fission process.The structure near the minimum and saddle point of the PES in the Z=118,119,120 nuclei is demonstrated simultaneously.Based on the potential energy curves,general trends of the evolution of the fission barrier heights and widths are also studied.The triaxial deformation in these superheavy mass regions plays a vital role in the first fission barrier,showing a significant reduction in both triaxial paths.In addition,the model-dependent fission barriers of proton-rich nuclei ^(295)Og,296119,and 297120 are analyzed briefly.Our studies could be valuable for synthesizing the superheavy new elements in the forthcoming HIAF and other facilities.
基金This work was supported in part by National Natural Science Foundation of China(No.51977042)Innovation Project of Guangxi Graduate Education(No.YCSW2020001).
文摘Integrated energy systems(IES)are under development to accommodate the widespread penetration of renewable energy into power systems.The universal utilization of coupling components makes the connection between power grids and heat grids even closer.This paper applies energy flow calculations to planning problems and explores a method for selecting coupling components in the integrated electrical and heating systems.This process is based on the analysis of energy flow distribution and the comprehensive indexes,which include operation cost and the penalty cost of wind curtailment and solar energy curtailment.Besides,a selection method of coupling components installation locations based on energy flow calculations is provided.At last,an IES with 5 electrical buses and 5 heating nodes,and a 9-bus electrical power system with a 31-node heating transmission system are chosen to study the specific application problems in detail as well as to elucidate the effectiveness of the proposed method.It turned out that the relevant coupling components and their positions can be selected according to the indexes obtained by integrated electrical-hydraulic-thermal calculation.This proposed method is conducive to the planning of integrated energy systems.
基金supported by a grant from the Institute of General Medical Sciences,National Institutes of Health,award number 1R01GM093937-01.
文摘Many molecular events are associated with small or large conformational changes occurring in the corresponding proteins.Modeling such changes is a challenge and requires significant amount of computing time.From point of view of electrostatics,these changes can be viewed as a reorganization of local charges and dipoles in response to the changes of the electrostatic field,if the cause is insertion or deletion of a charged amino acid.Here we report a large scale investigation of modeling the changes of the folding energy due to single mutations involving charged group.This allows the changes of the folding energy to be considered mostly electrostatics in origin and to be calculated with DelPhi assigning residue-specific value of the internal dielectric constant of protein.The predicted energy changes are benchmarked against experimentally measured changes of the folding energy on a set of 257 single mutations.The best fit between experimental values and predicted changes is used to find out the effective value of the internal dielectric constant for each type of amino acid.The predicted folding free energy changes with the optimal,amino acid specific,dielectric constants are within RMSD=0.86 kcal/mol from experimentally measured changes.
基金Supported by the National Natural Science Foundation of China(11975209,U2032211,12075287)the Physics Research and Development Program of Zhengzhou University(32410017)+1 种基金the Project of Youth Backbone Teachers of Colleges and Universities of Henan Province(2017GGJS008)the Polish National Science Centre(2016/21/B/ST2/01227)。
文摘We propose and test a new method of estimating the model parameters of the phenomenological BetheWeizsacker mass formula.Based on the Monte Carlo sampling of a large dataset,we obtain,for the first time,a Cauchy-type parameter distribution formed by the exact solutions of linear equation systems.Using the maximum likelihood estimation,the location and scale parameters are evaluated.The estimated results are compared with those obtained by solving overdetermined systems,e.g.,the solutions of the traditional least-squares method.Parameter correlations and uncertainty propagation are briefly discussed.As expected,it is also found that improvements in theoretical modeling(e.g.,considering microscopic corrections)decrease the parameter and propagation uncertainties.