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1.
用光电子成像技术和从头算法研究Ag-(CH3OH)x (x=1, 2)和AgOCH3-. 从AgOCH3-振动分辨的光电子谱得 到AgOCH3-的绝热和垂直电离能分别为1.29(2)和1.34(2) eV. Ag-(CH3OH)1,2相似文献   

2.
本文基于离子分子SH2-基态势能面,应用含时波包方法研究了反应S-(2P)+H2(1Σ+g)→SH-(1Σ)+H(2S)的动力学行为. 给出了反应几率和积分截面随碰撞能的变化关系,结果表明,在讨论的所有碰撞能量范围内二者均存在显著的振荡结构. 当初始转动量子数j=0,2,4,6,8,10和振动量子数v=0,1,2,3,4时,从总反应几率数值计算中可以看出,双原子H2的振动激发和转动激发显著提高了反应活性. 同时积分散射截面的理论值与前人的实验值相符合.  相似文献   

3.
本文使用交叉分子束方法研究了氟原子和振动激发态氘分子D2(v=1, j=0)的反应. 使用受激拉曼抽运的方法制备了振动激发的D2分子. 实验中未观测到来自于旋轨耦合激发态氟原子F*(2P1/2)与振动激发态D2分子的贡献. 观测到来自于旋轨耦合基态氟原子F(2P3/2)和振动激发态D2的反应信号,相应的产物DF分子布居于v''=2,3,4,5振动态上. 与振动基态反应F+D2(v=1,j=0)相比,振动激发态反应F+D2(v=1,j=0)生成的DF产物转动分布更“热”. 获得了振动激发反应的四个碰撞能在0.32至2.62 kcal/mol范围内的微分反应截面. 在最低的碰撞能0.32 kcal/mol下,所有振动态的DF产物都以后向散射为主. 随着碰撞能的增加,DF产物的角分布逐渐从后向转移到侧向. 测量了DF(v''=5)产物的前向微分散射截面随碰撞能变化的曲线. 前向散射的DF(v''=5)信号出现于1.0 kcal/mol. 在2.62 kcal/mol碰撞能下DF(v''=5)主要为前向散射.  相似文献   

4.
本文利用266 nm波长的激光及程序升温脱附的方法研究了甲醇在ZnO(0001)表面的光催化反应. TPD结果显示部分的CH3OH以分子的形式吸附在ZnO(0001)表面,而另外一部分在表面发生了解离. 实验过程中探测到H2,CH3·,H2O,CO,CH2O,CO2和CH3OH这些热反应产物. 紫外激光照射实验结果表明光照可以促进CH3OH/CH3O·解离形成CH2O,在程序升温或光照的过程中它又可以转变为HCOO-. CH2OHZn与OHad反应在Zn位点上形成H2O分子. 升温或光照都能促进CH3O·转变为CH3·. 该研究对CH3OH在ZnO(0001)表面的光催化反应机理提供了一个新的见解.  相似文献   

5.
本文采用含时波包方法和七维约化量子模型研究了典型碳氢氧化反应O(3P)+CHD3→OH+CD3中反应分子CHD3的转动模式特异性. 发现理论计算反应几率依赖于CHD3转动量子数J在分子对称轴上的投影$K$和在O-CHD3分子间轴上的投影Ktot,即PKtot=K=0>PKtot=K=J>PKtot=J,K=0=PKtot=0,K=J. 这种关系可以用反应物分子相对取向进行解释. 另外,反应物CHD3的转动激发(J≤4)表现出比较弱的促进作用,但是K=0转动态激发的促进作用比K=J的强,主要得益于K=Ktot=0分量的贡献. 该分量对应于CHD3的滚动转动,这种运动形式可以增大初始有效反应碰撞角度的范围.  相似文献   

6.
本文利用交叉分子束方法和离子速度成像技术,对H+HD→H2+D反应在1.17 eV碰撞能下的态-态反应动力学开展了高分辨实验研究. 实验采用1+1''(真空紫外+紫外)近阈值激光电离方式对反应中的D原子产物进行探测,获得了高角度分辨和高能量分辨的产物离子速度影像,进而精确获得了反应的态-态微分截面. 实验观测到了H2(v''=0,j''=1)和H2(v''=0,j''=3)振转产物角分布中与散射过程的干涉效应相联系的前向散射振荡. 这一研究进一步表明了化学反应微分截面的精确测量在气相态-态反应动力学研究中的重要性.  相似文献   

7.
H+CH3OH作为典型的多通道反应,在燃烧和星际中起着重要的作用. 本文基于在UCCSD(T)-F12a/AVTZ水平上计算的大量数据点,构建了该体系的全维精确势能面,并基于该势能面,研究了不同产物通道的模式特异动力学. 结果表明,O-H 伸缩、沿C-O轴的扭转以及C$-$H伸缩等模式的振动激发对H2+CH3O、H2+CH2OH、H2O+CH3和H+CH3OH四个产物通道有着不同的影响. 该研究有助于理解具有多个产物通道的复杂反应的模式特异动力学,进而帮助控制其竞争反应.  相似文献   

8.
利用密度泛函理论中杂化泛函理论方法计算了CH2和CH3自由基吸附在Cun(n=1~6)团簇上时C?H对称伸缩振动模式的软化性质,结果表明,CH2在Cun团簇上的吸附要比CH3的吸附强. 计算得到的C-H键的振动频率与实验上测量的这两个自由基吸附在Cu(111)表面的结果符合得很好,随着团簇尺寸的增加,C-H对称伸缩振动频率的软化(红移)越来越大.  相似文献   

9.
本文采用最近发展的十维含时波包方法研究了H+CH3D→H2+CH2D反应的模式选择性,计算了反应物CH3D在基态、CH3对称和不对称伸缩振动激发态、CD伸缩振动激发态以及CH3弯曲模式的基频和倍频激发态等6个初始状态下的反应几率. 计算结果表明,在碰撞能0.0∽1.0 eV区间内,激发CH3的任意一种伸缩振动模都能增强反应活性,而CD伸缩振动激发对反应的促进作用不明显. CH3弯曲振动模的基频激发对促进反应活性几乎没有影响,由于CH3对称伸缩振动模的基频与CH3弯曲振动模倍频之间的费米共振作用,CH3弯曲振动模的倍频激发显著增强了反应活性.  相似文献   

10.
甲醇与氟原子之间的抽氢反应可以生成HF和CH3O、CH2OH自由基等产物. 该反应在环境化学、燃烧化学、辐射化学和星际化学中都非常重要. 基于之前构建的全维高精度势能面,本文采用准经典轨线方法研究了该典型反应的动力学. 特别是使用正则模式分析方法确定了多原子产物CH3O和CH2OH的振动态分布. 研究发现,当反应物处于振转基态时,CH3O和CH2OH主要分布在基态. 当反应物CH3OH的OH伸缩模式激发为第一激发态时,产物CH2OH的OH伸缩模式、扭转模式、H2CO 面外弯曲模式及其组合会被有效激发. 在两条通道中,可用能量大部分都流入HF的振动能和产物的平动能,而自由基产物CH3O或CH2OH只得到非常少的能量,与实验结果一致,这也表明了自由基的旁观者性质.  相似文献   

11.
An analysis of interband optical transition strengths for a series of MO2 oxides is presented which gives clear evidence for a direct proportionality between transition strengths (as measured by the dispersion energy) and nearest-neighbor cation coordination number. It is also found that neither the extent of O2p orbital delocalization nor the d-electron configuration has a strong influence on transition strengths suggestin that these strengths can be viewed, to a good approximation, as intrinsic properties of valence s,p-electrons which are largely independent of band structure details.  相似文献   

12.
We have observed the 59Co spectra of the Laves phase Co compounds with Nd, Gd, Tb and Ho. We observe a spectrum consisting of a pair of lines for Nd, Tb and Ho compounds, because the Co sites are magnetically inequivalent in the presence of dipolar or pseudodipolar fields. For the heavy rare earth compounds, the magnitude of this splitting is comparable to the dipolar splitting produced by the neighboring spins, but for Nd it is much larger. The Nd compound is also anomalous in that the average hyperfine field is only 37.2 kOe while for the 3 heavy rare earth compounds it is about 60 kOe. The magnitude of the hyperfine field is discussed in terms of a simple model relating it to the cobalt moment and the rare earth spin.  相似文献   

13.
针对传统蚁群算法收敛速度慢、对动态路径变化适应性低的局限性,提出了一种基于局部信息获取策略的动态改进型蚁群算法。该算法利用局部信息获取策略,进行最优局部目标点的获取,然后调用改进蚁群算法获取局部区域内的最优路径,再重复循环获取新的最优局部目标点,直到找到全局目标点。与此同时,将提出的改进型蚁群算法应用于动态路径规划中的路径寻优与避障,仿真结果表明:提出的算法在具有与传统蚁群算法相当的路径优化效果的同时,能够有效适应障碍变化、大大提高了路径规划的收敛速度。  相似文献   

14.
Refractive index dispersion in the photon energy range from 0.5 eV to the fundamental gap energy is determined for CuInSe2, CuInTe2 and CuGaTe2 by measuring and analysing optical transmission spectra of thin films. Control measurements on GaAs thin films demonstrate the reliability of the method.  相似文献   

15.
The change of the discharge voltage when laser light crossing the discharge is tuned to a molecular transition has been measured. Experiments have been performed in the wavelength region between 570 nm and 620 nm with discharges in NH3, NO2, H2, N2, O2 and argon. Transitions from the ground states of NH2 and NO2 and transitions from metastable states of N2 and H2 have been detected. The spacial dependence of the opto galvanic in a low pressure dc-discharge of H2 and N2 has been studied.  相似文献   

16.
Fluorescence-excitation (wing) profiles of the Na-D doublet lines were measured over a wavelength range extending from 0.3 to 200 Å from the line center for the red D1 and blue D2 wings and from 0.3 to 3 Å for the red D2 and the blue D1 wings, respectively. The line profiles were determined with the aid of a tunable CW dye-laser as a background source by measuring the total fluorescence intensity observed on detuning the laser wavelength. The flames were premixed, laminar, shielded flames at 1 atm, with temperatures ranging from 1860 to 2270 K; N2 and Ar served as diluent gases. The line core and near-wing profiles (i.e. the region covering 0.3<Δλ<7 Å for the outer wings and 0.3<Δλ<3 Å for the inner ones) in all of the flames studied appeared to have the same frequency dependence, regardless of the nature and concentrations of the gases used. The blue D2-line profile followed an unexpected (-2.2) law, while the other three profiles obeyed the theoretically expected (-2) law (the dispersion profile function). The line profile in the Δλ range between the impact and quasistatic regions was found to depend on the main perturbers involved. We found that the far blue D2- and red D1-wings in the Ar-diluted H2/O2 flame obeyed the (-54) and (-32) laws, respectively, as predicted by the quasi-static theory for the Lennard-Jones interaction. For the N2-diluted C2H2/O2 and H2/O2 flames, we did not find these wing dependences in the Δλ range investigated.  相似文献   

17.
Reflectivity spectra of CuInSe2, CuInTe2 and CuGaTe2 are measured in the photon energy range from 2 to 9 eV. All compounds exhibit nearly the same reflectivity structures, and a comparison with measurements on the other Cu-III-VI2 semiconductors shows that the band structures of all Cu-III-VI2 compounds should be very similar except the energy range near the fundamental edge.  相似文献   

18.
Microwave linewidths of C2H4O (κ = -0.41) broadened by H2, N2, O2, and CO2 and considering dipole-quadrupole interactions have been calculated using the Mehrotra-Boggs theory (1977). This theory accounts satisfactorily for observed linewidths  相似文献   

19.
Photoelectron and electronic absorption spectra of SCl2, S2Cl2, S2Br2, and (CH3)2S2 have been measured and analyzed. Quantum chemical calculations (CNDO/ 2 and MWH (Mulliken-Wolfsberg-Helmholtz) have been carried out and the electronic structures have been described in terms of molecular orbital theory. The variation in differential photoionization cross-section as a function of incident photon energy and results of MO computations are used to identify ionization bands and assign ground state MO configurations. Suggested ground state electronic structures coupled with computed virtual MO's are used to interpret the visible and near-ultraviolet electronic absorption spectra. The low energy excited states are described as molecular states followed by the initial members of Rydberg series. Calculated oscillator strengths for molecular transitions are in good agreement with those observed experimentally. Quantum defects, δ, for the Rydberg states have been calculated from the Rydberg equation using the adiabatic first ionization potential.  相似文献   

20.
Linewidths of CO self-broadening and broadened by N2, O2, H2, HCI, NO, and CO2 have been calculated using different contributions in the intermolecular dispersion potential.The quadrupole moment of some perturbers has been determined by comparison between calculated and observed linewidths. The values obtained for the quadrupole moments may depend on the dispersion potential, especially when it is low (as is the case for N2, O2 and H2). For CO-CO and CO-NO, the electrostatic interactions including the octupole moment yield good results for the linewidths for high |m|-values.  相似文献   

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