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1.
In order to explore the isotope effect on stereo dynamics, we investigate the trajectory calculations of Ar+H2+/D2+/T2+ and Ar+T2+ reactions on the ab initio potential energy surface constructed by us and calculate the distributions of product polarization P(θr), P(r) and four generalized polarization-dependent differential cross-sections. The product rotational alignment parameters (P2(j' · k)) for the title reactions are compared and discussed with mass factors. Furthermore, the angular distributions of the product rotational vectors in the form of polar plot in θr and r are presented. The results indicate that the stereo dynamics properties of the title reactions are sensitive to the mass factor.  相似文献   

2.
The vector correlations between products and reagents for the reactions Ne+H2+, Ne+D2+, and Ne+T2+ are calculated by means of the quasi-classical trajectory method on a new potential energy surface constructed by Lfi et al, [J. Chem. Phys. 2010 132, 014303]. The polarization-dependent differential cross-sections (27π/σ)(dσ00/dωt), (2π/σ)(dσ20/dwt), (27π/σ)(dσ22+/dwt), and (2π/σ)(dσ21-/dwt), and the distributions of P(θr), P(φ), and P(θr, Cr) are calculated. The isotopic effect, which is associated with the difference in mass factor among the three reactions, is revealed.  相似文献   

3.
Keywords:SystematicDiscrepancyEnthalpyG2ExperimentIntroducedbyPopleandco-workers〔1-4〕,thewelknownG2abinitioprocedure,asarelia...  相似文献   

4.
用全相对论量子力学方法计算了电子组态为[Rn]5f26d17s1的U的全部214个电子状态的能级,基态为5K5。设UO2为线型(R∞h),U和O2均为基态,则UO2的可能电子状态有3,5,7Σ-g,3,5,7πg,…。UO2的基态不大可能为1Σ+g。  相似文献   

5.
We have investigated fragment emission from molecularions in H2^r collisions between S^q and H2 with incident energies of 12.5, 15.625, 18.75, 21.875, 25, 28.125, 31.25, 34.375, 37.5, 40.625, and 43.75 keV/u, respectively. The energy distributions of the fragments are measured by time-of-flight techniques. The experimental results show evidences for molecular Coulomb explosion and dissociation. A program[1] is estab-lished based on the Monte Carlo technique to simulate the time-of-flight spectrum of fragment ions with different initialkinetic energy in ion-Molecule collisions. Simulations are done for S^2 H2 collisions and compared with experimental results.  相似文献   

6.
本文讨论了在硼硅酸盐玻璃系统中引入二价 Ba2 、Pb2 和四价 Ti4 后 ,由于 Pb2 和Ti4 配位结构的变化 ,引起 Pb2 、Ti4 场强及其与 O2 -离子间距的变化 ,对 Li /Na 离子交换产生影响 ,从而改变折射率差值 (ΔN )和折射率分布 .  相似文献   

7.
用一束波长为360.55nm的激光,通过N2O分子的(3 1)共振增强多光子电离过程制备纯净的母体离子N2O^ X^2Π3/2,1/2(000).用另一束可调谐激光将N2O^ 离子激发至预解离态A^2Σ^ ,利用飞行时间质谱检测解离碎片NO^ 离子强度随光解光波长的变化,在278—328nm波长范围内获得了光解碎片的激发(PHOFEX)谱.观测到了N2O^ 离子A^2Σ^ ←X^2Π电子跃迁较丰富的振动谱带.通过对PHOFEX光谱的标识,获得了A^2Σ^态较准确和全面的分子光谱常数.  相似文献   

8.
采用光外差-磁旋转-速度调制吸收光谱技术,在可见光波段范围16800-17573cm^-1,对N2^+的A^2Ⅱu-X^2Σg^+(12,6)、(11,5)、(7,2)带和B^2Σu^+-x^2Σg^+(1,5)带进行了测量和分析,推导了双原子分子振动转能级在受到微扰作用时的有效哈密顿量形式,并分析了N^2+的A^Ⅱu-B^2Σu^+之间存在的微扰相互作用,通过与实验数据的拟合得到了精确的电子态微扰常数ξe、η。  相似文献   

9.
Using the quasi-classical trajectory method, the product rotational polarization of the ion-molecule reaction He^+D2^+ has been calculated at different collision energies on the PALMIERI potential energy surface [Palmieri et al. Mol. Phys. 98 (2000) 1835]. The distribution angle between k and j′, P(Or), the distribution of the dihedral angle P(Фr), and the angular distribution of product rotational vectors in the form of polar plots in θr and Фr are calculated. In addition, four polarization-dependent differential cross sections are also presented in the center-of-mass frame, respectively. The results indicate that the rotational polarization of the product HeD^+ presents different characters for different collision energies. These discrepancies may be ascribed to the different collision energies and constructions of the potential energy surface.  相似文献   

10.
束嵘  周映雪 《发光学报》1998,19(3):245-247
在国家同步辐射实验室的时间分辨光谱站(U10B光束线)研究掺杂Eu2+的卤磷酸盐:(Ca,Sr,Ba)5(PO4)3ClEu2+样品和(Ca,Sr)5(PO4)3ClEu2+的真空紫外辐照特性、反射光谱.前者在185nm光的激发下,60分钟内没有观察到明显的发光强度下降;而后者在185nm光的激发下,15分钟内就可以观察到其450nm发光的明显变化,从强到弱,直至完全消失.测量了两种样品的反射谱(100nm至400nm),并根据K-K关系计算得出的吸收谱,我们认为:由于Ba2+的加入,改变了晶格对称性,(O)-色心的能级发生变化,晶体对185nm附近紫外光的吸收明显降低,从而起到了耐185nm辐照的作用  相似文献   

11.
惠萍  陈启洲 《中国物理 C》2000,24(9):805-809
提出变形集团展开法研究2+1维SU(3)格点规范场的胶球质量,这种方法采用相边空心图的线性组合作为试探波函数,并引入了Wilson圈图的平均值。计算结果表明,变形集团展开的真空能量比普通集团展开法方法的真空能量低,0^++胶球质量m/e^2的二阶和三阶结果在耦合常数β=4.5-8.0区间,表现出较好的标度行为和良好的收敛性。  相似文献   

12.
本文运用密度泛函理论DFT-UB3LYP方法, 对2Sr+、2Ba+采用相对论校正赝势基组SDD, 对N、O、H采用6-311+G(2d,p)基组, 计算研究了气相中碱土金属离子2Sr+、2Ba+介入N2O (1∑+) 和 H2 (1∑+g)反应的微观机理, 优化了二重态势能面上各反应物、中间体和过渡态的构型特征, 用频率分析方法和内禀反应坐标方法(IRC)对过渡态进行了验证. 运用Kozuch撰写的能量跨度模型(Energetic Span Model, δE),确定了决定循环反应速率的决速过渡态(TDTS)和决速中间体(TDI), 并利用转化频率(Turnover Frequency,TOF)评估了催化性能. 结果表明:从热力学性质分析2Sr+、2Ba+离子对N2O (1∑+) 和 H2 (1∑+g)反应很好的催化作用,可得到目标产物N2 (1∑+g) 和 H2O (1A1), 却从动力学性质分析主要反应产物为N2、SrOH+ (BaOH+)和H, 最终动力学因素在主题反应中起决定性作用,以上结论与实验观测结果相符.  相似文献   

13.
The SrZnP2OT:Eu^2+, Mn^2+ phosphor is synthesized by high temperature solid state reaction. The luminescence properties and the energy transfer between Eu^2+ and Mn^2+ are investigated. The emission bands of this phosphor peaked at 42Ohm and 67Ohm are originated from the 5d → 4f transition of Eu^2+ and from the 4T1 (4G) --〉 6A1 (6S) transit/on of Mn^2+, respectively. With the increasing Mn^2+ concentration, the intensity of fixed concentra- tion Eu^2+ decreases and the intensity of Mn^2+ also increases. It is suggested that there is an energy transfer from Eu^2+ to Mn^2+ in SrZnP2O7 host. According to Dexter's energy transfer formula of multipolar interaction, the energy transfer between Eu^2+ and Mn^2+ is due to the electric dipole-quadrupole interaction of the resonance transfer.  相似文献   

14.
CdCl2:V^2+和CdI2:V^2+的g因子和零场分裂研究   总被引:2,自引:0,他引:2  
研究了CdCl2:V^2+和CdI:V^2+的EPRg因子和零场分裂D。在计算中既考虑了中心过渡金属离子SO耦合作用,也考虑了配体SO耦合作用的贡献,结果表明,对某些共价性强和配体SO耦合系数大的络合物,在研究其EPR性质时应考虑到双SO耦合作用的共同贡献。  相似文献   

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16.
纳米晶ZrO2:Pr^3+与ZrO2:Pr^3+,Sm^3+发光研究   总被引:10,自引:0,他引:10  
采用化学共沉淀法制备了纳米晶ZrO2:pr^3+粉体,所制备的纳米晶ZrO2:Pr^3+粉体中Pr^3+的强室温特征发射的两个主发射带为^1D2-^2H4和^3P0-^3H4跃迁。不同热处理温度下纳米晶ZrO2:Pr^3+晶体结构不同,因此它们的发光不同;ZrO2基质向Pr^3+有能量传递,在高温煅烧得到的单斜相配位场中能量传递较好。荧光强度与Pr^3+浓度的关系研究表明:^3P0和^1D2功能级有不同的猝灭规律,由于[^1D2,^3H4]→[^1G4,^3F4]的交叉弛豫,使得^1D2-^3H4跃迁的猝灭浓度很低,在我们的实验中,掺0.1mol%Pr^3+时^1D2-^3H4地跃迁发射最强,掺2mol%Pr^3+时^3R0-^3H4跃迁发射最强。文章制备的纳米晶ZrO2:Pr^3+,Sm^3+中Sm^3+的^4G(5-2)~^6H(7/2)跃迁荧光峰因Pr^3+加入而增强,这除了两种离子某些能级相近产生荧光发射的叠加效应外,还存在Pr^3+→Sm^3+的能量传递。  相似文献   

17.
采用共沉淀法制备了一系列Al2 O3含量由低到高的ZrO2-Al2 O3固溶体,并研究了固溶体的晶相结构以及稀土Er3+在固溶体中的上转换发光增强机制。XRD结果表明固溶体为四方晶相ZrO2结构,Al2 O3的最高固溶度约为20 mol%。上转换发光光谱分析表明,Er3+掺杂ZrO2室温下具有绿色上转换荧光发射,通过共掺杂Yb3+和M o6+离子,使得Er3+掺杂ZrO2的绿色上转换发光强度增强了约20倍,获得了明亮的黄绿色上转换发光。基质ZrO2通过与Al2 O3固溶形成复合氧化物,由于产生的大量氧空位缺陷的能级与Er3+的4 F7/2能级高度相接近,增强了Yb3+-MoO2-4基团(2 F7/2,3 T2)能级向Er3+的4 F7/2能级的能量传递。通过形成固溶体复合氧化物基质材料,使得Er3+的绿色上转换发光在获得20倍增强的基础上又提高了8倍。绿色与红色上转换发光比例的变化也提高了材料的色纯度,上转换发光由黄绿色变为纯绿色。  相似文献   

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20.
We employ the semirigid vibrating rotor target (SVRT) model to study the influence of rotational and vibrational excitation of the reagent on reactivity for the reaction H NH3. The excitation of the pseudo H-NH2 stretching vibration of the SVRT model gives significant enhancement of reaction probability. Detailed study of the influence of initial rotational states on reaction probability shows strong steric effect. The steric effect of polyatomic reactions, treated by the SVRT model, is more complex and richer than theoretical calculations involving linear molecular models.  相似文献   

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