The 3D Underwater Sensor Network(USNs)has become the most optimistic medium for tracking and monitoring underwater environment.Energy and collision are two most critical factors in USNs for both sparse and dense regio...The 3D Underwater Sensor Network(USNs)has become the most optimistic medium for tracking and monitoring underwater environment.Energy and collision are two most critical factors in USNs for both sparse and dense regions.Due to harsh ocean environment,it is a challenge to design a reliable energy efficient with collision free protocol.Diversity in link qualities may cause collision and frequent communication lead to energy loss;that effects the network performance.To overcome these challenges a novel protocol Forwarder Selection Energy Efficient Routing(FSE2R)is proposed.Our proposal’s key idea is based on computation of node distance from the sink,Residual Energy(RE)of each node and Signal to Interference Noise Ratio(SINR).The node distance from sink and RE is computed for reliable forwarder node selection and SINR is used for analysis of collision.The novel proposal compares with existing protocols like H2AB,DEEP,and E2LR to achieve Quality of Service(QoS)in terms of through-put,packet delivery ratio and energy consumption.The comparative analysis shows that FSE2R gives on an average 30%less energy consumption,24.62%better PDR and 48.31%less end-to-end delay compared to other protocols.展开更多
The relativistic mean-field approach was implemented in the Lanzhou quantum molecular dynamics transport model(LQMD.RMF). Using the LQMD.RMF, the properties of collective flow and pion production were investigated sys...The relativistic mean-field approach was implemented in the Lanzhou quantum molecular dynamics transport model(LQMD.RMF). Using the LQMD.RMF, the properties of collective flow and pion production were investigated systematically for nuclear reactions with various isospin asymmetries. The directed and elliptic flows of the LQMD.RMF are able to describe the experimental data of STAR Collaboration. The directed flow difference between free neutrons and protons was associated with the stiffness of the symmetry energy, that is, a softer symmetry energy led to a larger flow difference. For various collision energies, the ratio between the π^(-) and π^(+) yields increased with a decrease in the slope parameter of the symmetry energy. When the collision energy was 270 MeV/nucleon, the single ratio of the pion transverse momentum spectra also increased with decreasing slope parameter of the symmetry energy in both nearly symmetric and neutron-rich systems.However, it is difficult to constrain the stiffness of the symmetry energy with the double ratio because of the lack of threshold energy correction on the pion production.展开更多
Here wc report calculation of the differential interference angles (including b≤p gild b≥p ) for singlet-triplet mixed states of Na2(A^1∑u^+,ν=8-b^3∏0u,ν=14) system in collision with Na, in order to study t...Here wc report calculation of the differential interference angles (including b≤p gild b≥p ) for singlet-triplet mixed states of Na2(A^1∑u^+,ν=8-b^3∏0u,ν=14) system in collision with Na, in order to study the collision- induced quantum interference on rotational energy transfer in an atom-diatom system. The calculation is based on the first-order Born approximation of time-dependent perturbation theory, and the anisotropic Lennard-Jones intcraction potentials are also employed, The relationships between differential interference angle and impact parameter, including collision diameter and velocity, are obtained,展开更多
A four-state model considering the relative velocity distribution function for calculating the cross section of laserinduced collisional energy transfer in a Sr Li system is presented and profiles of laser-induced col...A four-state model considering the relative velocity distribution function for calculating the cross section of laserinduced collisional energy transfer in a Sr Li system is presented and profiles of laser-induced collision cross section are obtained. The resulting spectra obtained from different intermediate states are strongly asymmetrical in an opposite asymmetry. Both of the two intermediate states have contributions to the final state, and none of the intermediate states should be neglected. The peak of the laser-induced collisional energy transfer (LICET) profile shifts toward the red and the FWHM becomes narrower obviously with laser field intensity increasing. A cross section of 1.2 × 10^-12 cm2 at a laser field intensity of 2.17 ×107 V/m is obtained, which indicates that this collision process can be an effective way to transfer energy selectively from a storage state to a target state. The existence of saturation for cross section with the increase of the laser intensity shows that the high-intensity redistribution of transition probabilities is an important feature of this process, which is not accounted for in a two-state treatment.展开更多
Collisional quantum interference (CQI) in the intramolecular rotational energy transfer was observed in experiment by Sha and co-workers. The interference angle, which measuring the degree of the coherence, were mea...Collisional quantum interference (CQI) in the intramolecular rotational energy transfer was observed in experiment by Sha and co-workers. The interference angle, which measuring the degree of the coherence, were measured in the experiment of the static cell. Based on the first Born approximation of time dependent perturbation theory, taking into accounts the anisotropic Lennard-Jones interaction potentials, this paper describes the theoretical model of CQI in intramolecular rotational energy transfer in an atom-diatom collision system. In the model, the differential interference angle for the experiment of the molecular beam is calculated, the changing tendencies of the differential interference angle with the impact parameter and collision partners are obtained. This theoretical model is important for understanding or performing this kind of experiments.展开更多
The quasi-classical trajectory (QCT) is calculated to study the stereodynamics properties of the title reaction H(^2S) + NH (X^3 ∑^-, v = 0, j = 0)→ N(^4S) + H2 on the ground state ^4A″ potential energy s...The quasi-classical trajectory (QCT) is calculated to study the stereodynamics properties of the title reaction H(^2S) + NH (X^3 ∑^-, v = 0, j = 0)→ N(^4S) + H2 on the ground state ^4A″ potential energy surface (PES) constructed by Zhai and Han [2011 Jr. Chem. Phys. 135 104314]. The calculated QCT reaction probabilities and cross sections are in good agreement with the previous theoretical results. The effects of the collision energy on the k-kt distribution and the product polarization of H2 are studied in detail. It is found that the scattering direction of the product is strongly dependent on the collision energy. With the increase in the collision energy, the scattering directions of the products change from backward scattering to forward scattering. The distribution of P(Or) is strongly dependent on the collision energy below the lower collision energy (about 11.53 kcal/mol). In addition, the P((Pr) distribution dramatically changes as the collision energy increases. The calculated QCT results indicate that the collision energy plays an important role in determining the stereodynamics of the title reaction.展开更多
We experimentally observe the signature of electron emission resulting from a single binary encounter mechanism in the intermediate collision energy regime of 30 keV/u He2+ on argon. Electron emission spectra in the ...We experimentally observe the signature of electron emission resulting from a single binary encounter mechanism in the intermediate collision energy regime of 30 keV/u He2+ on argon. Electron emission spectra in the transfer ionization are obtained and compared with classical calculations from a two-step model considering the initial electron velocity and re-scattering of the binary encounter electron in the recoil potential. Although the present reaction is actually a four-body problem, the model starting from a binary encounter gives out surprisingly good agreement with the experimental data. Our studies show that orbital velocities of the electron affect the emission patterns of ionized electrons significantly.展开更多
In order to study the collisional quantum interference (CQI) on rotational energy transfer in atom-diatom system, we have studied the relation of the integral interference angle and differential interference angle i...In order to study the collisional quantum interference (CQI) on rotational energy transfer in atom-diatom system, we have studied the relation of the integral interference angle and differential interference angle in Naq-Na2 (A1 ∑u^+,v=8-b^3∏0u,v=14) collision system. In this paper, based on the first-Born approximation of timedependent perturbation theory and taking into accounts the anisotropic effect of Lennard-Jones interaction potentials, we present a theoretical model of collisional quantum interference in intramolecular rotational energy transfer, and a relationship between differential and integral interference angles.展开更多
We presented an experimental apparatus combining the H-atom Rydberg tagging time-of-flight technique and the laser detonation source for studying crossed beam reactions at hyperthermal collision energies. The prelimin...We presented an experimental apparatus combining the H-atom Rydberg tagging time-of-flight technique and the laser detonation source for studying crossed beam reactions at hyperthermal collision energies. The preliminary study of the F+D2→DF+D reaction at hyperthermal collision energy of 23.84 kJ/mol was performed. Two beam sources were used in this study: one is the hyperthermal F beam source produced by a laser detonation process, and the other is D2 beam source generated by liquid-N2 cooled pulsed valve. Vibrational state-resolved di erential cross sections (DCSs) of product for the title reaction were determined. From the product vibrational state-resolved DCS, it can be concluded that products DF(v'=0, 1, 2, 3) are predominantly distributed in the sideway and backward scattering directions at this collision energy. However, the highest vibrational excited product DF(v'=4), is clearly peaked in the forward direction. The probable dynamical origins for these forward scattering products were analyzed and discussed.展开更多
The electron excitation processes of H(1s)+He(1s^(2))→H(2s/2p)+He(1s^(2))are studied in impact energy range of 20-2000 e V/u by using the quantum-mechanical molecular orbital close-coupling(QMOCC)method.Total and sta...The electron excitation processes of H(1s)+He(1s^(2))→H(2s/2p)+He(1s^(2))are studied in impact energy range of 20-2000 e V/u by using the quantum-mechanical molecular orbital close-coupling(QMOCC)method.Total and state-selective cross sections have been obtained and compared with the available theoretical and experimental results.The results agree well with available measurements in the overlapping energy regions overall.The comparison of our results with other theoretical calculations further demonstrates the importance of considering a sufficient number of channels.The datasets presented in this paper,including the excitation cross sections,are openly available at https://www.doi.org/10.57760/sciencedb.j00113.00083.展开更多
The effect of collision energy on the magnetically tuned^(6)Li-^(6)Li Feshbach resonance(FR)is investigated theoretically by using the coupled-channel(CC)method for the collision energy ranging from 1μK·kBto 100...The effect of collision energy on the magnetically tuned^(6)Li-^(6)Li Feshbach resonance(FR)is investigated theoretically by using the coupled-channel(CC)method for the collision energy ranging from 1μK·kBto 100μK·kB.At the collision energy of 1μK·kB,the resonance positions calculated are 543.152 Gs(s wave,the unit 1 Gs=10^(-4)T),185.109 Gs(p wave|ml|=0),and 185.113 Gs(p wave|ml|=1),respectively.The p-wave FR near 185 Gs exibits a doublet structure of 4 mGs,associated with dipole-dipole interaction.With the increase of the collision energy,it is found that the splitting width remains the same(4 mGs),and that the resonance positions of s and p waves are shifted to higher magnetic fields with the increase of collision energy.The variations of the other quantities including the resonance width and the amplitude of the total scattering section are also discussed in detail.The thermally averaged elastic rate coefficients at T=10,15,20,25 K are calculated and compared.展开更多
The product rotational polarizations of reaction Li-SHF→LiF-kH at different collision energies, as well as at the different vibrational states and rotational states, are calculated by using the quasi-classical trajec...The product rotational polarizations of reaction Li-SHF→LiF-kH at different collision energies, as well as at the different vibrational states and rotational states, are calculated by using the quasi-classical trajectory method based on a new potential energy surface constructed by Aguado et al. [J. Chem. Phys. 119(2003) 10088]. We investigate the Mignment and the orientation of the product molecule by calculating the P(θr, φr) distribu- tions describing polar angle distribution, the P(θr) distributions describing the k-j' correlation and the P(φr) distributions describing the k-k'-j' correlation. We also explore the dependence of reaction probabilities and cross sections on the rotational and vibrational quantum number of the title reaction. It is concluded that the vibrational state has more important impact on the angular distribution, reaction probability and cross section.展开更多
The reac dynamics on Ba+BrCH_3→BaBr+CH_3 has been investigated in the first proposed potential energy surface of the generalized LEPS type,using the quasiclassical trajectory method.In simulation of the conditions in...The reac dynamics on Ba+BrCH_3→BaBr+CH_3 has been investigated in the first proposed potential energy surface of the generalized LEPS type,using the quasiclassical trajectory method.In simulation of the conditions in molecular beam experiments,the results of the present study show significant effect of the reagent collision energy on the dynamics of the reaction,and are in good agreement with the experimental ones.展开更多
The limit of rotational energy transfer in atom-diatomic systems due to inelastic collision was investigated over the wide range of collision energy, reduced mass and potential parameters of F2-He system. The IICS (i...The limit of rotational energy transfer in atom-diatomic systems due to inelastic collision was investigated over the wide range of collision energy, reduced mass and potential parameters of F2-He system. The IICS (integral inelastic cross-sections) is obtained by the IOSAM (infinite order sudden approximation method) and predicted by PG (power-gap) law in the variation of cross-sections. The investigation provided that the classical limit of angular momentum transfer is given by hard ellipsoid potential is meaningful even the cross-sections computed on the real potential, provided the classical turning point on the surface of soft potential is assumed as hard potential surface.展开更多
Wireless Sensor Networks (WSNs) are one of the fastest growing and emerging technologies in the field of Wireless Networking today. The applications of WSNs are extensively spread over areas like Military, En-vironmen...Wireless Sensor Networks (WSNs) are one of the fastest growing and emerging technologies in the field of Wireless Networking today. The applications of WSNs are extensively spread over areas like Military, En-vironment, Health Care, Communication and many more. These networks are powered by batteries and hence energy optimization is a major concern. One of the factors that reduce the energy efficiency of the WSN is collision which occurs due to the high density of data packets in a typical communication channel. This paper aims at minimizing the effects of congestion leading to collision in the network by proposing an effective algorithm. This can be done by optimizing the size of the contention window by introducing pa-rameters like source count and α. If the contention window of a node is low, it results in collision. If the size of the contention window of a node is high then it results in a medium access delay. Thus minimizing colli-sion and medium access delay of data packets conserve energy.展开更多
We have observed the dominant wing spectroscopy of energy pooling collision near the boundary layer involving Cs atoms under the condition of moderate-to-high optical depths at line-centre. It appears from our experim...We have observed the dominant wing spectroscopy of energy pooling collision near the boundary layer involving Cs atoms under the condition of moderate-to-high optical depths at line-centre. It appears from our experimental investigations that the energy-pooling fluorescence presents about 16 spectral lines, and all the lines can be assigned to the Cs atomic transitions. We find that all lines of the energy-pooling retrofluorescence from the heated Cs atomic vapour cell show two-peak profiles. In addition, its pumping power linear dependence in the energy pooling process has been measured and analysed.展开更多
The stereodynamics of the reaction of Ca + HCl are calculated at three different collision energies based on the potential energy surface [Verbockhaven G et al. 2005 J. Chem. Phys. 122 204307] using quasi-classical t...The stereodynamics of the reaction of Ca + HCl are calculated at three different collision energies based on the potential energy surface [Verbockhaven G et al. 2005 J. Chem. Phys. 122 204307] using quasi-classical trajectory theory. The polarization-dependent differential cross sections (PDDCSs) (2π/σ )(dσ 00 /dω t ), (2π/σ )(dσ 20 /dωt ), (2π/σ )(dσ 22+ /dωt ), (2π/σ )(dσ 21 /dω t ) and the distributions of P(θ r ), P(φr ), and P(θr ,φr ) are calculated. The results indicate that the rotational polarization of the CaCl product presents different characteristics for the different collision energies, and the effects of the collision energy on the vector potential, including the alignment, orientation, and PDDCSs, are not obvious.展开更多
The threshold energies of radial flow in reactions of ^40 Ca-^40Ca and ^48Ca+ ^48Ca in central collisions are investigated within an isospin dependent quantum molecular dynamics model by using three different forms o...The threshold energies of radial flow in reactions of ^40 Ca-^40Ca and ^48Ca+ ^48Ca in central collisions are investigated within an isospin dependent quantum molecular dynamics model by using three different forms of symmetry energy. It is found that the neutron-rich system has smaller threshold energy of radial flow and this quantity depends on the form of symmetry potential. It is indicated that the threshold energy of radial flow can provide a new method to determine the symmetry energy of asymmetric nuclear matter.展开更多
The energy density for the central region in relativistic heavy-ion collisions can be estimated via the pseudorapidity distribution of transverse energy.The way to estimate the local energy density for the central reg...The energy density for the central region in relativistic heavy-ion collisions can be estimated via the pseudorapidity distribution of transverse energy.The way to estimate the local energy density for the central region in relativistic heavy-ion collisions is proposed,in which only final state particles emitted from the same source are included.The energy density arrived in the NA49 experiments is about 0.9 GeV/fm^(3).展开更多
The reactions induced by intermediate energy heavy ions are investigated.The evap-orated fragment multiplicity and excitation energy distributions are calculated and comparedwith the experimental data of the reaction ...The reactions induced by intermediate energy heavy ions are investigated.The evap-orated fragment multiplicity and excitation energy distributions are calculated and comparedwith the experimental data of the reaction Ar+Ag at 50 and 70 MeV/u.展开更多
基金The authors would like to thank for the support from Taif University Researchers Supporting Project number(TURSP-2020/10),Taif University,Taif,Saudi Arabia.
文摘The 3D Underwater Sensor Network(USNs)has become the most optimistic medium for tracking and monitoring underwater environment.Energy and collision are two most critical factors in USNs for both sparse and dense regions.Due to harsh ocean environment,it is a challenge to design a reliable energy efficient with collision free protocol.Diversity in link qualities may cause collision and frequent communication lead to energy loss;that effects the network performance.To overcome these challenges a novel protocol Forwarder Selection Energy Efficient Routing(FSE2R)is proposed.Our proposal’s key idea is based on computation of node distance from the sink,Residual Energy(RE)of each node and Signal to Interference Noise Ratio(SINR).The node distance from sink and RE is computed for reliable forwarder node selection and SINR is used for analysis of collision.The novel proposal compares with existing protocols like H2AB,DEEP,and E2LR to achieve Quality of Service(QoS)in terms of through-put,packet delivery ratio and energy consumption.The comparative analysis shows that FSE2R gives on an average 30%less energy consumption,24.62%better PDR and 48.31%less end-to-end delay compared to other protocols.
基金This study was supported by the National Natural Science Foundation ofChina(Nos.12147106,12175072,and 11722546)the Talent Programof South China University of Technology(No.20210115).
文摘The relativistic mean-field approach was implemented in the Lanzhou quantum molecular dynamics transport model(LQMD.RMF). Using the LQMD.RMF, the properties of collective flow and pion production were investigated systematically for nuclear reactions with various isospin asymmetries. The directed and elliptic flows of the LQMD.RMF are able to describe the experimental data of STAR Collaboration. The directed flow difference between free neutrons and protons was associated with the stiffness of the symmetry energy, that is, a softer symmetry energy led to a larger flow difference. For various collision energies, the ratio between the π^(-) and π^(+) yields increased with a decrease in the slope parameter of the symmetry energy. When the collision energy was 270 MeV/nucleon, the single ratio of the pion transverse momentum spectra also increased with decreasing slope parameter of the symmetry energy in both nearly symmetric and neutron-rich systems.However, it is difficult to constrain the stiffness of the symmetry energy with the double ratio because of the lack of threshold energy correction on the pion production.
基金This work was supported by National Natural Science Foundation of China(No.10374040).
文摘Here wc report calculation of the differential interference angles (including b≤p gild b≥p ) for singlet-triplet mixed states of Na2(A^1∑u^+,ν=8-b^3∏0u,ν=14) system in collision with Na, in order to study the collision- induced quantum interference on rotational energy transfer in an atom-diatom system. The calculation is based on the first-order Born approximation of time-dependent perturbation theory, and the anisotropic Lennard-Jones intcraction potentials are also employed, The relationships between differential interference angle and impact parameter, including collision diameter and velocity, are obtained,
文摘A four-state model considering the relative velocity distribution function for calculating the cross section of laserinduced collisional energy transfer in a Sr Li system is presented and profiles of laser-induced collision cross section are obtained. The resulting spectra obtained from different intermediate states are strongly asymmetrical in an opposite asymmetry. Both of the two intermediate states have contributions to the final state, and none of the intermediate states should be neglected. The peak of the laser-induced collisional energy transfer (LICET) profile shifts toward the red and the FWHM becomes narrower obviously with laser field intensity increasing. A cross section of 1.2 × 10^-12 cm2 at a laser field intensity of 2.17 ×107 V/m is obtained, which indicates that this collision process can be an effective way to transfer energy selectively from a storage state to a target state. The existence of saturation for cross section with the increase of the laser intensity shows that the high-intensity redistribution of transition probabilities is an important feature of this process, which is not accounted for in a two-state treatment.
基金Project supported by the Research Foundation of Department of Education of Liaoning Province (Grant No 20060347)the NNSFC (Grant No 10374040)
文摘Collisional quantum interference (CQI) in the intramolecular rotational energy transfer was observed in experiment by Sha and co-workers. The interference angle, which measuring the degree of the coherence, were measured in the experiment of the static cell. Based on the first Born approximation of time dependent perturbation theory, taking into accounts the anisotropic Lennard-Jones interaction potentials, this paper describes the theoretical model of CQI in intramolecular rotational energy transfer in an atom-diatom collision system. In the model, the differential interference angle for the experiment of the molecular beam is calculated, the changing tendencies of the differential interference angle with the impact parameter and collision partners are obtained. This theoretical model is important for understanding or performing this kind of experiments.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11074103,10974078,and 11174117)the Discipline Construction Fund of Ludong University,China
文摘The quasi-classical trajectory (QCT) is calculated to study the stereodynamics properties of the title reaction H(^2S) + NH (X^3 ∑^-, v = 0, j = 0)→ N(^4S) + H2 on the ground state ^4A″ potential energy surface (PES) constructed by Zhai and Han [2011 Jr. Chem. Phys. 135 104314]. The calculated QCT reaction probabilities and cross sections are in good agreement with the previous theoretical results. The effects of the collision energy on the k-kt distribution and the product polarization of H2 are studied in detail. It is found that the scattering direction of the product is strongly dependent on the collision energy. With the increase in the collision energy, the scattering directions of the products change from backward scattering to forward scattering. The distribution of P(Or) is strongly dependent on the collision energy below the lower collision energy (about 11.53 kcal/mol). In addition, the P((Pr) distribution dramatically changes as the collision energy increases. The calculated QCT results indicate that the collision energy plays an important role in determining the stereodynamics of the title reaction.
基金Supported by the National Basic Research Program of China under Grant No 2010CB832902the National Natural Science Foundation of China under Grants Nos U1332128 and 11274317,10979007 and 11004202the Program of One Hundred Talents of the Chinese Academy of Sciences
文摘We experimentally observe the signature of electron emission resulting from a single binary encounter mechanism in the intermediate collision energy regime of 30 keV/u He2+ on argon. Electron emission spectra in the transfer ionization are obtained and compared with classical calculations from a two-step model considering the initial electron velocity and re-scattering of the binary encounter electron in the recoil potential. Although the present reaction is actually a four-body problem, the model starting from a binary encounter gives out surprisingly good agreement with the experimental data. Our studies show that orbital velocities of the electron affect the emission patterns of ionized electrons significantly.
基金Supported by the National Natural Science Foundation of China under Grant No.10374040the Foundation of the Educational Department of Liaoning Province under Grant Nos.2008290 and 20060347
文摘In order to study the collisional quantum interference (CQI) on rotational energy transfer in atom-diatom system, we have studied the relation of the integral interference angle and differential interference angle in Naq-Na2 (A1 ∑u^+,v=8-b^3∏0u,v=14) collision system. In this paper, based on the first-Born approximation of timedependent perturbation theory and taking into accounts the anisotropic effect of Lennard-Jones interaction potentials, we present a theoretical model of collisional quantum interference in intramolecular rotational energy transfer, and a relationship between differential and integral interference angles.
基金supported by the National Natural Science Foundation of China (No.21473015, No.21203016, No.41574101, No.21673232, No.21773213)the Foundation for the Author of National Excellent Doctoral Dissertation of China (No.201222)
文摘We presented an experimental apparatus combining the H-atom Rydberg tagging time-of-flight technique and the laser detonation source for studying crossed beam reactions at hyperthermal collision energies. The preliminary study of the F+D2→DF+D reaction at hyperthermal collision energy of 23.84 kJ/mol was performed. Two beam sources were used in this study: one is the hyperthermal F beam source produced by a laser detonation process, and the other is D2 beam source generated by liquid-N2 cooled pulsed valve. Vibrational state-resolved di erential cross sections (DCSs) of product for the title reaction were determined. From the product vibrational state-resolved DCS, it can be concluded that products DF(v'=0, 1, 2, 3) are predominantly distributed in the sideway and backward scattering directions at this collision energy. However, the highest vibrational excited product DF(v'=4), is clearly peaked in the forward direction. The probable dynamical origins for these forward scattering products were analyzed and discussed.
基金supported by the National Natural Science Foundation of China(Grant Nos.12204288,11934004,and 12274040)
文摘The electron excitation processes of H(1s)+He(1s^(2))→H(2s/2p)+He(1s^(2))are studied in impact energy range of 20-2000 e V/u by using the quantum-mechanical molecular orbital close-coupling(QMOCC)method.Total and state-selective cross sections have been obtained and compared with the available theoretical and experimental results.The results agree well with available measurements in the overlapping energy regions overall.The comparison of our results with other theoretical calculations further demonstrates the importance of considering a sufficient number of channels.The datasets presented in this paper,including the excitation cross sections,are openly available at https://www.doi.org/10.57760/sciencedb.j00113.00083.
基金supported by the National Key Research and Development Program of China(Grant No.2018YFA0306503)the National Natural Science Foundation of China(Grant Nos.21873016 and 12174044)+1 种基金the International Cooperation Fund Project of DBJI(Grant No.ICR2105)the Fundamental Research Funds for the Central Universities(Grant No.DUT21LK08)。
文摘The effect of collision energy on the magnetically tuned^(6)Li-^(6)Li Feshbach resonance(FR)is investigated theoretically by using the coupled-channel(CC)method for the collision energy ranging from 1μK·kBto 100μK·kB.At the collision energy of 1μK·kB,the resonance positions calculated are 543.152 Gs(s wave,the unit 1 Gs=10^(-4)T),185.109 Gs(p wave|ml|=0),and 185.113 Gs(p wave|ml|=1),respectively.The p-wave FR near 185 Gs exibits a doublet structure of 4 mGs,associated with dipole-dipole interaction.With the increase of the collision energy,it is found that the splitting width remains the same(4 mGs),and that the resonance positions of s and p waves are shifted to higher magnetic fields with the increase of collision energy.The variations of the other quantities including the resonance width and the amplitude of the total scattering section are also discussed in detail.The thermally averaged elastic rate coefficients at T=10,15,20,25 K are calculated and compared.
基金Supported by the National Natural Science Foundation of China under Grants No 11274205
文摘The product rotational polarizations of reaction Li-SHF→LiF-kH at different collision energies, as well as at the different vibrational states and rotational states, are calculated by using the quasi-classical trajectory method based on a new potential energy surface constructed by Aguado et al. [J. Chem. Phys. 119(2003) 10088]. We investigate the Mignment and the orientation of the product molecule by calculating the P(θr, φr) distribu- tions describing polar angle distribution, the P(θr) distributions describing the k-j' correlation and the P(φr) distributions describing the k-k'-j' correlation. We also explore the dependence of reaction probabilities and cross sections on the rotational and vibrational quantum number of the title reaction. It is concluded that the vibrational state has more important impact on the angular distribution, reaction probability and cross section.
文摘The reac dynamics on Ba+BrCH_3→BaBr+CH_3 has been investigated in the first proposed potential energy surface of the generalized LEPS type,using the quasiclassical trajectory method.In simulation of the conditions in molecular beam experiments,the results of the present study show significant effect of the reagent collision energy on the dynamics of the reaction,and are in good agreement with the experimental ones.
文摘The limit of rotational energy transfer in atom-diatomic systems due to inelastic collision was investigated over the wide range of collision energy, reduced mass and potential parameters of F2-He system. The IICS (integral inelastic cross-sections) is obtained by the IOSAM (infinite order sudden approximation method) and predicted by PG (power-gap) law in the variation of cross-sections. The investigation provided that the classical limit of angular momentum transfer is given by hard ellipsoid potential is meaningful even the cross-sections computed on the real potential, provided the classical turning point on the surface of soft potential is assumed as hard potential surface.
文摘Wireless Sensor Networks (WSNs) are one of the fastest growing and emerging technologies in the field of Wireless Networking today. The applications of WSNs are extensively spread over areas like Military, En-vironment, Health Care, Communication and many more. These networks are powered by batteries and hence energy optimization is a major concern. One of the factors that reduce the energy efficiency of the WSN is collision which occurs due to the high density of data packets in a typical communication channel. This paper aims at minimizing the effects of congestion leading to collision in the network by proposing an effective algorithm. This can be done by optimizing the size of the contention window by introducing pa-rameters like source count and α. If the contention window of a node is low, it results in collision. If the size of the contention window of a node is high then it results in a medium access delay. Thus minimizing colli-sion and medium access delay of data packets conserve energy.
基金Project supported by the National Natural Science Foundation of China (Grant Nos 60378004 and 10674086), the Specialized Research Fund for Doctoral Program of Higher Education of China (Grant No 20040108002), the State Key Development Program for Basic Research of China (Grant Nos 2006CB921603 and 2006CB921102), the Shanxi Provincial Foundation for Leaders of Disciplines in Science, China, and the Program for Changjiang Scholars and Innovative Research Team in University (Grant No IRT0516).
文摘We have observed the dominant wing spectroscopy of energy pooling collision near the boundary layer involving Cs atoms under the condition of moderate-to-high optical depths at line-centre. It appears from our experimental investigations that the energy-pooling fluorescence presents about 16 spectral lines, and all the lines can be assigned to the Cs atomic transitions. We find that all lines of the energy-pooling retrofluorescence from the heated Cs atomic vapour cell show two-peak profiles. In addition, its pumping power linear dependence in the energy pooling process has been measured and analysed.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 11174117, 10974078, 11274205, 11274206, 11147026, and 31200545)
文摘The stereodynamics of the reaction of Ca + HCl are calculated at three different collision energies based on the potential energy surface [Verbockhaven G et al. 2005 J. Chem. Phys. 122 204307] using quasi-classical trajectory theory. The polarization-dependent differential cross sections (PDDCSs) (2π/σ )(dσ 00 /dω t ), (2π/σ )(dσ 20 /dωt ), (2π/σ )(dσ 22+ /dωt ), (2π/σ )(dσ 21 /dω t ) and the distributions of P(θ r ), P(φr ), and P(θr ,φr ) are calculated. The results indicate that the rotational polarization of the CaCl product presents different characteristics for the different collision energies, and the effects of the collision energy on the vector potential, including the alignment, orientation, and PDDCSs, are not obvious.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10575012 and 10435020, the Science Foundation of Beljlng, and the Science Foundation of Beijing Normal University.
文摘The threshold energies of radial flow in reactions of ^40 Ca-^40Ca and ^48Ca+ ^48Ca in central collisions are investigated within an isospin dependent quantum molecular dynamics model by using three different forms of symmetry energy. It is found that the neutron-rich system has smaller threshold energy of radial flow and this quantity depends on the form of symmetry potential. It is indicated that the threshold energy of radial flow can provide a new method to determine the symmetry energy of asymmetric nuclear matter.
基金Supported in part by the National Natural Science Foundation of China under Grant No.19947001the Doctoral Programme Foundation of Institution of Higher Education,the State Education Commission of China.
文摘The energy density for the central region in relativistic heavy-ion collisions can be estimated via the pseudorapidity distribution of transverse energy.The way to estimate the local energy density for the central region in relativistic heavy-ion collisions is proposed,in which only final state particles emitted from the same source are included.The energy density arrived in the NA49 experiments is about 0.9 GeV/fm^(3).
基金The Project Supported by Shanxi Provincial Foundation of Leading Man in Science,Shanxi Provincial Foundation of Scholarly Exchange and China National Education Committee Foundation of Scholarly Exchange
文摘The reactions induced by intermediate energy heavy ions are investigated.The evap-orated fragment multiplicity and excitation energy distributions are calculated and comparedwith the experimental data of the reaction Ar+Ag at 50 and 70 MeV/u.