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Chinese Physics C 2012年第6期36卷 538-543页

作者：杨振伟丁明明陈少敏王喆张锋高原宁 Key Laboratory of Particle&Radiation Imaging(Tsinghua University) Ministry of Education Department of Engineering Physics Tsinghua University Center for High Energy Physics Tsinghua University Physics Department Brookhaven National Laboratory

Abstract： Knowledge of Ve-Fe/Pb differential cross sections for a^e energy below several tens of MeV scale is believed to be crucial in understanding supernova physics. In a segmented detector at a spallation neutron source, ve energy reconstructed from the electron range measurement is strongly affected because both multiple scattering and electromagnetic showers occur along the electron passage in target materials. In order to estimate these effects, a simulation study has been performed with a cube block model assuming perfect tracking precision. The energy spectrum distortion is observed to be proportional to the atomic number of the target material. Feasibility of unfolding the distorted ~ energy spectrum is studied for both Fe and Pb. An evaluation of the statistical accuracy attainable is therefore provided for a segmented detector.

关键词： unfolding neutrino differential cross section segmented detector Monte Carlo SNS supernova

Electron-Helium Atom Collisions in the Presence of a Bichromatic Laser Field

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Communications in Theoretical Physics 2008年第8期50卷 477-480页

作者： ZHU Zun-Lue LIANG Ming-Chao SUN Jin-Feng College of Physics and Information Engineering Henan Normal University Xinxiang 453007 China Department of Physics Luoyang Normal College Luoyang 471022 China

The differential cross section （DCS） for electron-helium atom collisions in the presence of a bichromatic CO2 laser field is investigated as a function of the scattering angle θ by employing first-Born approximation （FBA） with a simple screening electric potential. We discuss in detail the influence of the scattering geometry, the photon energy and the number of photons exchanged on the DCSs. These illustrate that the three factors have important effects on the elastic scattering and the screening electric potential is effective.

关键词： differential cross section bichromatic laser field first Born approximation scattering geometry

Vector correlations study of the reaction N(~2D) + H_2(X^1Σ_g^+) →NH(a^1?) + H(~2S) with different collision energies and reagent vibration excitations

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Chinese Physics B 2015年第11期24卷 224-230页

作者：李永庆张永嘉赵金峰赵美玉丁勇 Department of Physics Liaoning University State Key Laboratory of Molecular Reaction Dynamics Dalian Institute of Chemical PhysicsChinese Academy of Sciences Institute of Theoretical Simulation Chemistry Academy of Fundamental and Interdisciplinary SciencesHarbin Institute of Technology

Vector correlations of the reaction N（2D）＋H2（X1∑g＋） NH（a1△）→ ＋ H（2S） are studied based on a recent DMBE- SEC PES for the first excited state ofNH2 [J. Phys. Chem. A 114 9644 （2010）] by using a quasi-classical trajectory method. The effects of collision energy and the reagent initial vibrational excitation on cross section and product polarization are investigated for v = 0-5 and j = 0 states in a wide collision energy range （10-50 kcal/mol）. The integral cross section could be increased by H2 vibration excitation remarkably based on the DMBE-SEC PES. The different phenomena of differential cross sections with different collision energies and reagent vibration excitations are explained. Particularly, the NH molecules are scattered mainly in the backward hemisphere at low vibration quantum number and evolve from backward to forward direction with increasing vibration quantum number, which could be explained by the fact that the vibrational excitation enlarges the H-H distance in the entrance channel, thus enhancing the probability of collision between N atom and H atom. A further study on product polarization demonstrates that the collision energy and vibrational excitation of the reagent remarkably influence the distributions of P（Or）, P（（Pr）, and P（Or, （Pr）.

关键词： vector correlations vibrational excitation differential cross section stereodynamics rotationalpolarization

State-to-state quantum dynamics of N(2D) ＋ HD (v =0, j = 0) reaction

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Chinese Physics B 2016年第12期25卷 228-234页

作者：张勇 Department of Physics Tonghua Normal University Tonghua 134002 China

The N（2D）＋ HD （v = 0, j = 0） reaction has been studied by a quantum time-dependent wave packet approach with a second-order split operator on the potential energy surface of Li et al. （Li Y, Yuan J, Chen M, Ma F and Sun M J. Comput. Chem. 34 1686）. The rovibrationally resolved reaction probability, vibrationally integral cross section, and differential cross section of the NH ＋ D and ND ＋ H channel are investigated at the state-to-state level of theory. The experimental data of the thermal rate constant of two output channels is very scare, but the sum of the two output channels is in excellent agreement with the experimental data which was reported by Umemoto et al. It may imply that the thermal rate constants of the two output channels are accurate and reliable.

关键词： N(2D) + HD time-dependent wave packet differential cross section thermal rate constant

Effects of Single Quantum Rotational Excitation on Reaction of F+D_(2) at Collision Energies between 44 and 164 cm^(-1)

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Chinese Journal of Chemical Physics 2022年第2期35卷 263-269,I0001页

作者： Zhirun Jiao Heilong Wang Yu Li Hongtao Zhang Chunlei Xiao Xueming Yang State Key Laboratory of Molecular Reaction Dynamics Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China School of Chemical Sciences University of Chinese Academy of SciencesBeijing 100049China Department of Chemical Physics University of Science and Technology of ChinaHefei 230026China College of Science Southern University of Science and TechnologyShenzhen 518055China

There is no general picture to describe the influences of reagent rotational excitation on the reaction,which proceeds via the tunnelling mechanism at collision energies far below the reaction *** we report a crossed beam study on the prototypical reaction of F+D_(2)(v=0,j=0,1)→DF(v′)+D at collision energies between 44 and 164 cm^(-1)with the scheme of multichannel D-atom Rydberg tagging time-of-flight *** state resolved differential cross sections are obtained at v′=2,3,4 *** effects of reagent rotational excitation were investigated at an equivalent amount of total energy by precise tuning of translational *** with translation,the rotation of D_(2) is found to be more efficient to promote the title *** differences introduced by rotation of D_(2) are also observed on the angular distribution and quantum state distribution of DF *** hope the present work could provide an example for understanding the effects of reagent rotational excitation on the chemical reaction at energies that are much lower than the reaction barrier.

关键词： crossed beam experiment differential cross section Rotational excitation

State-to-state quantum dynamics of N(~2D)+HD(v=0,j=0) reaction

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Chinese Physics B 2016年第12期25卷 232-238页

作者：张勇 Department of Physics Tonghua Normal University

The N(~2D) + HD(v = 0, j = 0) reaction has been studied by a quantum time-dependent wave packet approach with a second-order split operator on the potential energy surface of Li et al.(Li Y, Yuan J, Chen M, Ma F and Sun M J. ***. 34 1686). The rovibrationally resolved reaction probability, vibrationally integral cross section, and differential cross section of the NH + D and ND + H channel are investigated at the state-to-state level of theory. The experimental data of the thermal rate constant of two output channels is very scare, but the sum of the two output channels is in excellent agreement with the experimental data which was reported by Umemoto et al. It may imply that the thermal rate constants of the two output channels are accurate and reliable.

关键词： N(2D)+HD time-dependent wave packet differential cross section thermal rate constant

Energy and rotation-dependent stereodynamics of H(~2S) + NH(a^1?) → H_2(X^1Σ_g^+) + N(~2D) reaction

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Chinese Physics B 2016年第2期25卷 135-142页

作者：李永庆杨云帆于洋张永嘉马凤才 Department of Physics Liaoning University State Key Laboratory of Molecular Reaction Dynamics Dalian Institute of Chemical PhysicsChinese Academy of Sciences

Quasi-classical trajectory calculations are performed to study the stereodynamics of the H（~2S）＋ NH（a^1？） →H_2（X^1Σ_g~＋）＋ N（~2D） reaction based on the first excited state NH_2（1~2A＇） potential energy surface reported by Li et al.[Li Y Q and Varandas A J C 2010 J. Phys. Chem. A 114 9644] for the first time. We observe the changes of differential cross-sections at different collision energies and different initial reagent rotational excitations. The influence of collision energy on the k-k＇ distribution can be attributed to a purely impulsive effect. Initial reagent rotational excitation transforms the reaction mechanism from insertion to abstraction. The effect of initial reagent rotational excitations on k-k＇ distribution can be explained by the rotational excitation enlarging the rotational rate of reagent NH in the entrance channel to reduce the probability of collision between incidence H atom and H atom of target molecular. We also investigate the changes of vector correlations and find that the rotational angular momentum vector j＇ of the product H_2 is not only aligned, but also oriented along the y axis. The alignment parameter, the disposal of total angular momentum and the reaction mechanism are all analyzed carefully to explain the polarization behavior of the product rotational angular moment.

关键词： differential cross section stereodynamics rotational excitation rotational polarization Vector cor- relation

differential, elastic integral and moment transfer cross sections for electron scattering from N2 at intermediate- and high-energies

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Chinese Physics B 2005年第2期14卷 331-335页

作者：刘玉芳孙金锋朱遵略杨向东 DepartmentofPhysics HenanNormalUniversityXinxiang453007China DepartmentofPhysics HenanNormalUniversityXinxiang453007China//InstituteofAtomicandMolecularPhysicsSichuanUniversityChengdu610065China InstituteofAtomicandMolecularPhysics SichuanUniversityChengdu610065China

A complex optical model potential modified by incorporating the concept of bonded atom, with the overlapping effect of electron clouds between two atoms in a molecule taken into consideration, is firstly employed to calculate the differential cross sections, elastic integral cross sections, and moment transfer cross sections for electron scattering from molecular nitrogen over the energy range 300-1000eV by using additivity rule model at Hartree-Fock level. The bondedatom concept is used in the study of the complex optical model potential composed of static, exchange, correlation polarization and absorption contributions. The calculated quantitative molecular differential cross sections, elastic integral cross sections, and moment transfer cross sections are compared with the experimental and theoretical ones wherever available, and they are found to be in good agreement with each other. It is shown that the additivity rule model together with the complex optical model potential modified by incorporating the concept of bonded atom is completely suitable for the calculations of differential cross section, elastic integral cross section and moment transfer cross section over the intermediate- and high-energy ranges.

关键词： electron scattering additivity rule differential cross section elastic integral cross section moment transfer cross section

State-to-state dynamics of F(~2P) + HO(~2Π) → O(~3P) + HF(~1Σ^+)reaction on 1~3A〞 potential energy surface

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Chinese Physics B 2018年第2期27卷 285-293页

作者：赵娟吴慧孙海波王立飞 College of Science Shandong Jiaotong University Jinan 250357 China State Key Laboratory of Molecular Reaction Dynamics Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116023 China College of Science Jiangnan University Wuxi 214122 China

State-to-state time-dependent quantum dynamics calculations are carried out to study F（2P）＋ HO（2ЦП（→ O（3P）＋ HF（1∑＋） reaction on 1^3A″ ground potential energy surface （PES）. The vibrationally resolved reaction probabilities and the total integral cross section agree well with the previous results. Due to the heavy-light-heavy （HLH） system and the large exoergicity, the obvious vibrational inversion is found in a state-resolved integral cross section. The total differential cross section is found to be forward-backward scattering biased with strong oscillations at energy lower than a threshold of 0.10 eV, which is the indication of the indirect complex-forming mechanism. When the collision energy increases to greater than 0.10 eV, the angular distribution of the product becomes a strong forward scattering, and almost all the products are distributed at θt = 0°. This forward-peaked distribution can be attributed to the larger J partial waves and the property of the F atom itself, which make this reaction a direct abstraction process. The state-resolved differential cross sections are basically forward-backward symmetric for v′ = 0, 1, and 2 at a collision energy of 0.07 eV; for a collision energy of 0.30 eV, it changes from backward/sideward scattering to forward peaked as v′ increasing from 0 to 3. These results indicate that the contribution of differential cross sections with more highly vibrational excited states to the total differential cross sections is principal, which further verifies the vibrational inversion in the products.

关键词： state-to-state quantum dynamics time-dependent wave packet differential cross section F(2P) + HO(2П)

Absolute differential, elastic integrated and mqment transfer cross sections for electron-OCS collisions at intermediate and high energies

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Chinese Physics B 2007年第6期16卷 1655-1659页

作者：施德恒孙金锋朱遵略马恒刘玉芳杨向东 College of Physics & Electronic Engineering Xinyang Normal University Xinyang 464000 China College of Physics & Information Engineering Henan Normal University Xinxiang 453007 China Institute of Atomic & Molecular Physics Sichuan University Chengdu 610065 China

A complex optical model potential modified by incorporating the concept of bonded atom, which takes into consideration the overlapping effect of electron clouds between atoms in a molecule, is firstly employed to calculate the absolute differential, elastic integrated and moment transfer cross sections for electron scattering by OCS over the incident energy range from 200 to 1000 eV using the additivity rule model at Hartree-Fock level. The calculated results are compared with those obtained by experiment and other theories wherever available, and good agreement is obtained over a wide energy range. It is shown that the additivity rule model together with the modified potential is completely suitable for calculating the absolute differential, elastic integrated and moment transfer cross sections of electron scattering by molecules such as OCS.

关键词： electron scattering additivity rule differential cross section elastic integrated cross section