A global three dimensional potential energy surface for the F+H2→HF+H reaction has been developed by spline interpolation of about 15,000 symmetry-unique ab initio points, obtained from the multi-reference configur...A global three dimensional potential energy surface for the F+H2→HF+H reaction has been developed by spline interpolation of about 15,000 symmetry-unique ab initio points, obtained from the multi-reference configuration interaction level with Davidson correction using the aug-cc-pV5Z basis set. In the entrance channel the spin-orbit coupling energy is also included.展开更多
The vibration states of transition molecule S<SUB>2</SUB>O, including both bending and stretching vibrations, are studied in the framework of dynamical symmetry groups . We get all the vibration spectra of...The vibration states of transition molecule S<SUB>2</SUB>O, including both bending and stretching vibrations, are studied in the framework of dynamical symmetry groups . We get all the vibration spectra of S<SUB>2</SUB>O by fitting 22 spectra data with 10 parameters. The fitting rms of the Hamiltonian is 2.12 cm<SUP>-1</SUP>. With the parameters and Lie algebraic theory, we give the analytical expression of the potential energy surface, which helps us to calculate the dissociation energy and force constants of S<SUB>2</SUB>O in the electronic ground state.展开更多
Full-dimensional adiabatic potential energy surfaces of the electronic ground state X and nine excited states A,I,B,C,D,D',D'',E' and F of H_(2)O molecule are developed at the level of internally contr...Full-dimensional adiabatic potential energy surfaces of the electronic ground state X and nine excited states A,I,B,C,D,D',D'',E' and F of H_(2)O molecule are developed at the level of internally contracted multireference configuration interaction with the Davidson correction.The potential energy surfaces are fitted by using Gaussian process regression combining permutation invariant polynomials.With a large selected active space and extra diffuse basis set to describe these Rydberg states,the calculated vertical excited energies and equilibrium geometries are in good agreement with the previous theoretical and experimental values.Compared with the well-investigated photodissociation of the first three low-lying states,both theoretical and experimental studies on higher states are still limited.In this work,we focus on all the three channels of the highly excited state,which are directly involved in the vacuum ultraviolet photodissociation of water.In particular,some conical intersections of D-E',E'-F,A-I and I-C states are clearly illustrated for the first time based on the newly developed potential energy surfaces(PESs).The nonadiabatic dissociation pathways for these excited states are discussed in detail,which may shed light on the photodissociation mechanisms for these highly excited states.展开更多
The revised new iterative method for solving the ground state of Schroedingerequation is deduced. Based on Green functions defined by quadratures along a single trajectory thisiterative method is applied to solve the ...The revised new iterative method for solving the ground state of Schroedingerequation is deduced. Based on Green functions defined by quadratures along a single trajectory thisiterative method is applied to solve the ground state of the double-well potential. The result iscompared to the one based on the original iterative method. The limitation of the asymptoticexpansion is also discussed.展开更多
We present a new six-dimensional potential energy surface for He-H2S including the intramolecular Q1,Q2,and Q3 normal modes for theν1 symmetric stretching,ν2 bending andν3 asymmetric stretching of H2S.The potential...We present a new six-dimensional potential energy surface for He-H2S including the intramolecular Q1,Q2,and Q3 normal modes for theν1 symmetric stretching,ν2 bending andν3 asymmetric stretching of H2S.The potential was calculated at the coupled-cluster singles and doubles with noniterative inclusion of connected triples[CCSD(T)]-F12a level with augmented correlation-consistent polarized-valence triple-zeta(aug-cc-p VTZ)basis set plus the midpoint bond function(3s3p2d1f1g).Three vibrationally averaged potentials with H2S at the vibrational ground stateν1 as well as the excited statesν2 andν3 were generated from the integration of the six-dimensional potential over the Q1,Q2 and Q3 coordinates.Each potential has a planar T-shaped global minimum,a planar local minimum,two inplane saddle points as well as an out-plane saddle point.The global minimum is located at R=3.46A,θ=109.9° andφ=0.0° with a well depth of 35.301 cm^-1.The radial discrete variable representation/angular finite basis representation method and the Lanczos algorithm were employed to calculate the rovibrational energy levels.The calculated band origins are blue-shifted(0.025 cm^-1 and 0.031 cm^-1)and(0.041 cm^-1 and 0.060 cm^-1)for He-(paraH2S)and He-(ortho-H2S)in theν2 andν3 region of the H2S molecule,respectively.展开更多
The vibrational levels and potential energy surface of a stable structure for S2O in the excited electronic states C^1A' were carried out with algebraic method. The vibrational spectra were obtained (with total quan...The vibrational levels and potential energy surface of a stable structure for S2O in the excited electronic states C^1A' were carried out with algebraic method. The vibrational spectra were obtained (with total quantum number v=20) by fitting 30 spectra data. The fitted rms(root mean square) error based on the Hamiltonian witb 9 parameters was 2.40 cm^-1. The dissociation energy and force constant were also determined by the analytical potential energy surface. The method is proved to be effective by comparing these results with the experimental data.展开更多
Two-photon dissociation dynamics of the OH radical is studied using the high-n Rydberg atom time-of-flight(HRTOF) technique. The H(2 S)+O(1 D) and H(2 S)+O(1 S) product channels are observed in the dissociation of the...Two-photon dissociation dynamics of the OH radical is studied using the high-n Rydberg atom time-of-flight(HRTOF) technique. The H(2 S)+O(1 D) and H(2 S)+O(1 S) product channels are observed in the dissociation of the OH radical on the 22Π and B2Σ+repulsive states, respectively, from sequential two-photon excitation via the A2Σ+(v′=2, J′=0.5-2.5)state. Both H+O product channels have anisotropic angular distributions, with β=-0.97 for H(2 S)+O(1 D) and 1.97 for H(2 S)+O(1 S). The anisotropic angular distributions are consistent with a mechanism of OH direct dissociation on the repulsive potential energy curves(PECs) leading to the H+O products. The OH bond dissociation energy D0(O-H) is determined to be 35580±15 cm-1.展开更多
The product branching ratio between different products in multichannel reactions is as important as the overall rate of reaction,both in terms of practical applications(e.g.models of combustion or atmosphere chemistry...The product branching ratio between different products in multichannel reactions is as important as the overall rate of reaction,both in terms of practical applications(e.g.models of combustion or atmosphere chemistry)in understanding the fundamental mechanisms of such chemical reactions.A global ground state potential energy surface for the dissociation reaction of deuterated alkyl halide CD_(3)CH_(2)F was computed at the CCSD(T)/CBS//B3 LYP/aug-cc-p VDZ level of theory for all species.The decomposition of CD_(3)CH_(2)F is controversial concerning C-F bond dissociation reaction and molecular(HF,DF,H_(2),D_(2),HD)elimination reaction.RiceRamsperger-Kassel-Marcus(RRKM)calculations were applied to compute the rate constants for individual reaction steps and the relative product branching ratios for the dissociation products were calculated using the steady-state approach.At the different energies studied,the RRKM method predicts that the main channel for DF or HF elimination from1,2-elimination of CD_(3)CH_(2)F is through a four-center transition state,whereas D_(2) or H_(2) elimination from 1,1-elimination of CD_(3)CH_(2)F occurs through a direct three-center elimination.At 266,248,and 193 nm photodissociation,the main product CD_(2)CH_(2)+DF branching ratios are computed to be 96.57%,91.47%,and 48.52%,respectively;however,at 157 nm photodissociation,the product branching ratio is computed to be 16.11%.Based on these transition state structures and energies,the following photodissociation mechanisms are suggested:at 266,248,193 nm,CD_(3)CH_(2)F→absorption of a photon→TS5→the formation of the major product CD_(2)CH_(2)+DF;at 157 nm,CD_(3)CH_(2)F→absorption of a photon→D/F interchange of TS1→CDH_(2)CDF→H/F interchange of TS2→CHD_(2)CHDF→the formation of the major product CHD_(2)+CHDF.展开更多
Based on the vibrational potential curves coupled with the minimum energy reaction path, the partial potential energy surface of the reaction I+HI→IH+I was constructed at the QCISD(T)//MP4SDQ level with pseudo po...Based on the vibrational potential curves coupled with the minimum energy reaction path, the partial potential energy surface of the reaction I+HI→IH+I was constructed at the QCISD(T)//MP4SDQ level with pseudo potential method. And the formation mechanism of the scattering resonance states of this reaction was well interpreted with the partial potential energy surface. The scattering resonance states of this reaction should belong to Feshbach resonance because of the coupling of the vibrational mode and the translational mode. With the one-dimensional square potential well model, the resonance width and lifetime of the I+HI(v=0)→IH(v'=0)+I state-to-state reaction were calculated, which preferably explained the high-resolved threshold photodetachment spectroscopy of the IHI- anion performed by Neumark et al..展开更多
The newly synthesized element 117 and its alpha-decay chains are systematically investigated in the framework of the relativistic mean field theory with parameter sets NL-Z2 and TMA. The ground-state properties of the...The newly synthesized element 117 and its alpha-decay chains are systematically investigated in the framework of the relativistic mean field theory with parameter sets NL-Z2 and TMA. The ground-state properties of the superheavy nuclei on the alpha-decay chains of 294 117 and 293 117 are calculated. The experimental alpha-decay energies and ha Jr-lives of the two alpha-decay chains are reasonably reproduced by the model The detailed discussions on the binding energies, alpha-decay energies, half-lives, quadrupole deformations, potential energy curves, and single particle levels of the two alpha-decay chains are made.展开更多
In this paper, a simplified model of the bistable piezoelectric cantilever beam with magnets is established, and the potential energy of the bistable system is analyzed. We have proposed the bistable L-shaped beam str...In this paper, a simplified model of the bistable piezoelectric cantilever beam with magnets is established, and the potential energy of the bistable system is analyzed. We have proposed the bistable L-shaped beam structure, which has the same geometry dimensions of the bistable straight beam in the first time. The comparative study on power generations and dynamic responses of the bistable straight beam and the bistable L-shaped beam plays an important role in exploring excellent piezoelectric generator.The experiment structure includes the base layer and the piezoelectric layer. The harmonic excitation is given to the system.Theoretical analysis results show that the potential energy function of the system has two obvious steady potential wells. In addition, the depth of the upper potential well is different from that of the lower potential well when the gravity potential energy is considered. Experimental results demonstrate that the power generation for the straight beam is better than that of the horizontally placed L-shaped beam when the excitation amplitude is 450 m V. There is the existence that the energy harvesting capacity of the bistable L-shaped beam is better than that of the bistable straight beam when the excitation amplitude is 400 m V.Furthermore, the power generation of the bistable L-shaped beam with the upper potential well is obviously better than that of the bistable L-shaped beam with the lower potential well. In addition, comparing with the straight beam, the dynamic response of the bistable L-shaped beam is more complex when the external excitation frequency is changed. It is also observed that the distance between the magnets has the obvious influence on the dynamic response of the bistable system. It is very effective to select the appropriate distance between the magnets to improve the power generation of the bistable energy harvester under the fixed excitation conditions.展开更多
In this paper, potential energy curves for the X1∑+, a3П, a'∑+, da△, A1П and I∑- states of CO have been calculated using complete active space se1f-consistent field and multi-reference configuration interacti...In this paper, potential energy curves for the X1∑+, a3П, a'∑+, da△, A1П and I∑- states of CO have been calculated using complete active space se1f-consistent field and multi-reference configuration interaction methods. The calculations have been performed at 108 nuclear separations from 0.7 to 4.0 A by the aug-cc-PVSZ basis set. Spectroscopic constants for the six low-lying electronic states are found in good agreement with experimental data. The vibrational states of the X1∑+ and A1П states are also calculated, which are reliable and accurate by comparison with the experimental data and the other theoretical values. The transition dipole moment (TDM) shows that the TDM of the two states (X1∑+→A1П)are reduced strongly with increase of bond length.展开更多
Configuration-constrained calculations of potential-energy surfaces for ^292 122 show the occurrence of multiquasiparticle high-K isomeric state at oblate superdeformation. Such state could play a unique role in super...Configuration-constrained calculations of potential-energy surfaces for ^292 122 show the occurrence of multiquasiparticle high-K isomeric state at oblate superdeformation. Such state could play a unique role in superheavy nuclei, with possible long life time from enhanced difficulty in fission due to additional barrier at oblate deformation, retardation in a decay due to unpaired nucleons, and hindrance in γ-ray transition due to K forbiddenness.展开更多
The study of speciation genetics is primarily concerned with identifying the genetic traits that allow divergent selec- tion to overcome the homogenizing effects of gene flow. Felsenstein reviewed this race between ge...The study of speciation genetics is primarily concerned with identifying the genetic traits that allow divergent selec- tion to overcome the homogenizing effects of gene flow. Felsenstein reviewed this race between gene flow and selection, con- cluding that speciation with gene flow was unlikely under a "two-allele model" (where two traits were necessary for reproductive isolation) but that divergence could occur quite easily under a "one-allele model." Despite this finding, much of the sympatric speciation research involving phytophagous insects has relied on a two-trait model, where insects evolve both preferences for and increased performance on novel host plants. Philopatry (a tendency to remain where one was born) is known to occur in phyto- phagous insects and is a single trait isolation mechanism. However, it is traditionally invoked as simply augmenting reproductive isolation. Species in the Enchenopa binotata complex are believed to have speciated in sympatry. They exhibit host plant prefe- rences, host specific performance advantages and strong philopatry. We experimentally shifted E. binotata to evolutionarily novel host plants. Previous research has demonstrated that the experimental population of insects possesses genetic variation in prefe- rence and performance to the novel host. The degree of philopatry at mating and egg-laying was assayed for the first four years under full choice conditions. Host plant preference and performance was assayed after eight years. Philopatry was an immediate and strong isolating mechanism, while preference for and performance on the novel host lagged. We therefore suggest that philo- patry may be a more important mechanism in the early stages of a host shift than previously believed [Current Zoology 59 (5): 658-666, 2013].展开更多
The singlet rigid Be--O dissociation potential energy curves correlating to the first four molecular limits of (BeH2O)^2+ com- plex were calculated using the multi-reference single and double excitation configurati...The singlet rigid Be--O dissociation potential energy curves correlating to the first four molecular limits of (BeH2O)^2+ com- plex were calculated using the multi-reference single and double excitation configuration interaction theory. The radial cou- plings of three low-lying IAl states were calculated and combined with adiabatic potential energy curves to investigate and charge- transfer collision dynamics by using quantum-mechanical molecular orbital close-coupling methods. It is found that the total charge-transfer cross sections are dominated by the Be^+(^2S)+H2O+(A^2A1) channel. The rate coefficients in the range of 10^-17 - 10^-12 cm^3/s are very sensitive to temperature below 1000 K. The complexation energy without charge-transfer was determined to be 143.6 kcal/mol, including zero-point vibration energy corrections. This is in good agreement with the previous results.展开更多
We obtain the energy spectrum and all the corresponding eigenfunctions of N-body Bose and Fermi systems with Quadratic Pair Potentials in one dimension. The original first excited state or energy level is disappeared ...We obtain the energy spectrum and all the corresponding eigenfunctions of N-body Bose and Fermi systems with Quadratic Pair Potentials in one dimension. The original first excited state or energy level is disappeared in one dimension, which results from the operation of symmetry or antisymmetry of identical particles. In two and higher dimensions, we give the energy spectrum and the analytical ground state wave [unctions and the degree of degeneracy. By comparison, we refine A vinash Khare's results by making some items in his article precisely.展开更多
基金This work was supported by the National Natural Science Foundation of China (No.20328304 and 20533060).
文摘A global three dimensional potential energy surface for the F+H2→HF+H reaction has been developed by spline interpolation of about 15,000 symmetry-unique ab initio points, obtained from the multi-reference configuration interaction level with Davidson correction using the aug-cc-pV5Z basis set. In the entrance channel the spin-orbit coupling energy is also included.
基金The project supported by National Natural Science Foundation of China and partly by the Science Foundation of Shandong Province of China
文摘The vibration states of transition molecule S<SUB>2</SUB>O, including both bending and stretching vibrations, are studied in the framework of dynamical symmetry groups . We get all the vibration spectra of S<SUB>2</SUB>O by fitting 22 spectra data with 10 parameters. The fitting rms of the Hamiltonian is 2.12 cm<SUP>-1</SUP>. With the parameters and Lie algebraic theory, we give the analytical expression of the potential energy surface, which helps us to calculate the dissociation energy and force constants of S<SUB>2</SUB>O in the electronic ground state.
基金supported by the National Natural Science Foundation of China(No.12047532,No.21733006,No.22073042,and No.22122302)。
文摘Full-dimensional adiabatic potential energy surfaces of the electronic ground state X and nine excited states A,I,B,C,D,D',D'',E' and F of H_(2)O molecule are developed at the level of internally contracted multireference configuration interaction with the Davidson correction.The potential energy surfaces are fitted by using Gaussian process regression combining permutation invariant polynomials.With a large selected active space and extra diffuse basis set to describe these Rydberg states,the calculated vertical excited energies and equilibrium geometries are in good agreement with the previous theoretical and experimental values.Compared with the well-investigated photodissociation of the first three low-lying states,both theoretical and experimental studies on higher states are still limited.In this work,we focus on all the three channels of the highly excited state,which are directly involved in the vacuum ultraviolet photodissociation of water.In particular,some conical intersections of D-E',E'-F,A-I and I-C states are clearly illustrated for the first time based on the newly developed potential energy surfaces(PESs).The nonadiabatic dissociation pathways for these excited states are discussed in detail,which may shed light on the photodissociation mechanisms for these highly excited states.
文摘The revised new iterative method for solving the ground state of Schroedingerequation is deduced. Based on Green functions defined by quadratures along a single trajectory thisiterative method is applied to solve the ground state of the double-well potential. The result iscompared to the one based on the original iterative method. The limitation of the asymptoticexpansion is also discussed.
基金supported by the National Natural Science Foundation of China(No.21973065)Sichuan Science and Technology Program(No.2018JY0172)。
文摘We present a new six-dimensional potential energy surface for He-H2S including the intramolecular Q1,Q2,and Q3 normal modes for theν1 symmetric stretching,ν2 bending andν3 asymmetric stretching of H2S.The potential was calculated at the coupled-cluster singles and doubles with noniterative inclusion of connected triples[CCSD(T)]-F12a level with augmented correlation-consistent polarized-valence triple-zeta(aug-cc-p VTZ)basis set plus the midpoint bond function(3s3p2d1f1g).Three vibrationally averaged potentials with H2S at the vibrational ground stateν1 as well as the excited statesν2 andν3 were generated from the integration of the six-dimensional potential over the Q1,Q2 and Q3 coordinates.Each potential has a planar T-shaped global minimum,a planar local minimum,two inplane saddle points as well as an out-plane saddle point.The global minimum is located at R=3.46A,θ=109.9° andφ=0.0° with a well depth of 35.301 cm^-1.The radial discrete variable representation/angular finite basis representation method and the Lanczos algorithm were employed to calculate the rovibrational energy levels.The calculated band origins are blue-shifted(0.025 cm^-1 and 0.031 cm^-1)and(0.041 cm^-1 and 0.060 cm^-1)for He-(paraH2S)and He-(ortho-H2S)in theν2 andν3 region of the H2S molecule,respectively.
基金This work Was supported by the National Natural Science Foundation of China(NSFCNo.10474050).
文摘The vibrational levels and potential energy surface of a stable structure for S2O in the excited electronic states C^1A' were carried out with algebraic method. The vibrational spectra were obtained (with total quantum number v=20) by fitting 30 spectra data. The fitted rms(root mean square) error based on the Hamiltonian witb 9 parameters was 2.40 cm^-1. The dissociation energy and force constant were also determined by the analytical potential energy surface. The method is proved to be effective by comparing these results with the experimental data.
基金supported by the US National Science Foundation (grant number CHE-1566636)UC MEXUS-CONACYT Collaborative Grant (CN-1668)DGAPA-UNAM for support through Project PAPIIT IN-115916.
文摘Two-photon dissociation dynamics of the OH radical is studied using the high-n Rydberg atom time-of-flight(HRTOF) technique. The H(2 S)+O(1 D) and H(2 S)+O(1 S) product channels are observed in the dissociation of the OH radical on the 22Π and B2Σ+repulsive states, respectively, from sequential two-photon excitation via the A2Σ+(v′=2, J′=0.5-2.5)state. Both H+O product channels have anisotropic angular distributions, with β=-0.97 for H(2 S)+O(1 D) and 1.97 for H(2 S)+O(1 S). The anisotropic angular distributions are consistent with a mechanism of OH direct dissociation on the repulsive potential energy curves(PECs) leading to the H+O products. The OH bond dissociation energy D0(O-H) is determined to be 35580±15 cm-1.
基金supported by the National Natural Science Foundation of China(No.91641116,No.21433004,No.91753103,and No.21933010)the NYU Global Seed Grantthe Laboratory and Equipment Management Office of ECNU。
文摘The product branching ratio between different products in multichannel reactions is as important as the overall rate of reaction,both in terms of practical applications(e.g.models of combustion or atmosphere chemistry)in understanding the fundamental mechanisms of such chemical reactions.A global ground state potential energy surface for the dissociation reaction of deuterated alkyl halide CD_(3)CH_(2)F was computed at the CCSD(T)/CBS//B3 LYP/aug-cc-p VDZ level of theory for all species.The decomposition of CD_(3)CH_(2)F is controversial concerning C-F bond dissociation reaction and molecular(HF,DF,H_(2),D_(2),HD)elimination reaction.RiceRamsperger-Kassel-Marcus(RRKM)calculations were applied to compute the rate constants for individual reaction steps and the relative product branching ratios for the dissociation products were calculated using the steady-state approach.At the different energies studied,the RRKM method predicts that the main channel for DF or HF elimination from1,2-elimination of CD_(3)CH_(2)F is through a four-center transition state,whereas D_(2) or H_(2) elimination from 1,1-elimination of CD_(3)CH_(2)F occurs through a direct three-center elimination.At 266,248,and 193 nm photodissociation,the main product CD_(2)CH_(2)+DF branching ratios are computed to be 96.57%,91.47%,and 48.52%,respectively;however,at 157 nm photodissociation,the product branching ratio is computed to be 16.11%.Based on these transition state structures and energies,the following photodissociation mechanisms are suggested:at 266,248,193 nm,CD_(3)CH_(2)F→absorption of a photon→TS5→the formation of the major product CD_(2)CH_(2)+DF;at 157 nm,CD_(3)CH_(2)F→absorption of a photon→D/F interchange of TS1→CDH_(2)CDF→H/F interchange of TS2→CHD_(2)CHDF→the formation of the major product CHD_(2)+CHDF.
基金Ⅴ. ACKN0WLEDGMENTS This work was supported by the National Natural Science Foundation of China (No.20573064) and Ph.D. Special Research Foundation of Chinese Education Department.
文摘Based on the vibrational potential curves coupled with the minimum energy reaction path, the partial potential energy surface of the reaction I+HI→IH+I was constructed at the QCISD(T)//MP4SDQ level with pseudo potential method. And the formation mechanism of the scattering resonance states of this reaction was well interpreted with the partial potential energy surface. The scattering resonance states of this reaction should belong to Feshbach resonance because of the coupling of the vibrational mode and the translational mode. With the one-dimensional square potential well model, the resonance width and lifetime of the I+HI(v=0)→IH(v'=0)+I state-to-state reaction were calculated, which preferably explained the high-resolved threshold photodetachment spectroscopy of the IHI- anion performed by Neumark et al..
基金Supported by National Natural Science Foundation of China under Grant Nos. 10735010, 10975072, and 11035001, by 973 National Major State Basic Research and Development of China under Grant No. 2007CB815004 and 2010CB327803, CAS Knowledge Innovation Project under Grant No. KJCX2-SW-N02, and by Research Fund of Doctoral Point under Grant No. 20100091110028
文摘The newly synthesized element 117 and its alpha-decay chains are systematically investigated in the framework of the relativistic mean field theory with parameter sets NL-Z2 and TMA. The ground-state properties of the superheavy nuclei on the alpha-decay chains of 294 117 and 293 117 are calculated. The experimental alpha-decay energies and ha Jr-lives of the two alpha-decay chains are reasonably reproduced by the model The detailed discussions on the binding energies, alpha-decay energies, half-lives, quadrupole deformations, potential energy curves, and single particle levels of the two alpha-decay chains are made.
基金supported by the National Natural Science Foundation of China(Grant Nos.11772008,11172009,11372015,11232009,10872010,11290152&10732020)
文摘In this paper, a simplified model of the bistable piezoelectric cantilever beam with magnets is established, and the potential energy of the bistable system is analyzed. We have proposed the bistable L-shaped beam structure, which has the same geometry dimensions of the bistable straight beam in the first time. The comparative study on power generations and dynamic responses of the bistable straight beam and the bistable L-shaped beam plays an important role in exploring excellent piezoelectric generator.The experiment structure includes the base layer and the piezoelectric layer. The harmonic excitation is given to the system.Theoretical analysis results show that the potential energy function of the system has two obvious steady potential wells. In addition, the depth of the upper potential well is different from that of the lower potential well when the gravity potential energy is considered. Experimental results demonstrate that the power generation for the straight beam is better than that of the horizontally placed L-shaped beam when the excitation amplitude is 450 m V. There is the existence that the energy harvesting capacity of the bistable L-shaped beam is better than that of the bistable straight beam when the excitation amplitude is 400 m V.Furthermore, the power generation of the bistable L-shaped beam with the upper potential well is obviously better than that of the bistable L-shaped beam with the lower potential well. In addition, comparing with the straight beam, the dynamic response of the bistable L-shaped beam is more complex when the external excitation frequency is changed. It is also observed that the distance between the magnets has the obvious influence on the dynamic response of the bistable system. It is very effective to select the appropriate distance between the magnets to improve the power generation of the bistable energy harvester under the fixed excitation conditions.
基金Project Supported by the Fundamental Research Funds for the Central Universities and the National Natural Science Foundation of China under Grant No. 61102024
文摘In this paper, potential energy curves for the X1∑+, a3П, a'∑+, da△, A1П and I∑- states of CO have been calculated using complete active space se1f-consistent field and multi-reference configuration interaction methods. The calculations have been performed at 108 nuclear separations from 0.7 to 4.0 A by the aug-cc-PVSZ basis set. Spectroscopic constants for the six low-lying electronic states are found in good agreement with experimental data. The vibrational states of the X1∑+ and A1П states are also calculated, which are reliable and accurate by comparison with the experimental data and the other theoretical values. The transition dipole moment (TDM) shows that the TDM of the two states (X1∑+→A1П)are reduced strongly with increase of bond length.
基金Supported by the National Natural Science Foundation of China under Grant No.11205120
文摘Configuration-constrained calculations of potential-energy surfaces for ^292 122 show the occurrence of multiquasiparticle high-K isomeric state at oblate superdeformation. Such state could play a unique role in superheavy nuclei, with possible long life time from enhanced difficulty in fission due to additional barrier at oblate deformation, retardation in a decay due to unpaired nucleons, and hindrance in γ-ray transition due to K forbiddenness.
文摘The study of speciation genetics is primarily concerned with identifying the genetic traits that allow divergent selec- tion to overcome the homogenizing effects of gene flow. Felsenstein reviewed this race between gene flow and selection, con- cluding that speciation with gene flow was unlikely under a "two-allele model" (where two traits were necessary for reproductive isolation) but that divergence could occur quite easily under a "one-allele model." Despite this finding, much of the sympatric speciation research involving phytophagous insects has relied on a two-trait model, where insects evolve both preferences for and increased performance on novel host plants. Philopatry (a tendency to remain where one was born) is known to occur in phyto- phagous insects and is a single trait isolation mechanism. However, it is traditionally invoked as simply augmenting reproductive isolation. Species in the Enchenopa binotata complex are believed to have speciated in sympatry. They exhibit host plant prefe- rences, host specific performance advantages and strong philopatry. We experimentally shifted E. binotata to evolutionarily novel host plants. Previous research has demonstrated that the experimental population of insects possesses genetic variation in prefe- rence and performance to the novel host. The degree of philopatry at mating and egg-laying was assayed for the first four years under full choice conditions. Host plant preference and performance was assayed after eight years. Philopatry was an immediate and strong isolating mechanism, while preference for and performance on the novel host lagged. We therefore suggest that philo- patry may be a more important mechanism in the early stages of a host shift than previously believed [Current Zoology 59 (5): 658-666, 2013].
文摘The singlet rigid Be--O dissociation potential energy curves correlating to the first four molecular limits of (BeH2O)^2+ com- plex were calculated using the multi-reference single and double excitation configuration interaction theory. The radial cou- plings of three low-lying IAl states were calculated and combined with adiabatic potential energy curves to investigate and charge- transfer collision dynamics by using quantum-mechanical molecular orbital close-coupling methods. It is found that the total charge-transfer cross sections are dominated by the Be^+(^2S)+H2O+(A^2A1) channel. The rate coefficients in the range of 10^-17 - 10^-12 cm^3/s are very sensitive to temperature below 1000 K. The complexation energy without charge-transfer was determined to be 143.6 kcal/mol, including zero-point vibration energy corrections. This is in good agreement with the previous results.
基金Supported by the National Natural Science Foundation of China under Grant No.10975125
文摘We obtain the energy spectrum and all the corresponding eigenfunctions of N-body Bose and Fermi systems with Quadratic Pair Potentials in one dimension. The original first excited state or energy level is disappeared in one dimension, which results from the operation of symmetry or antisymmetry of identical particles. In two and higher dimensions, we give the energy spectrum and the analytical ground state wave [unctions and the degree of degeneracy. By comparison, we refine A vinash Khare's results by making some items in his article precisely.