Capture of asymmetric top dipolar molecules by ions: Rate constants for capture of H2O, HDO, and D2O by arbitrary ions

The capture of rotationally state-selected and unselected asymmetric top polar molecules by ions is investigated. Analytical expressions (for all rotational states up to j = 2) of capture rate constants in the perturbed-rotor second-order limit are derived for application to low temperature conditions. Approximate analytical representations over wider temperature ranges are also given for rotationally unselected molecules. The capture of H₂O, D₂O, and HDO by arbitrary ions is chosen for demonstration of the approach. Capture rate constants for the about 60 reactions of H₂O with ions listed in the UMIST 2006 data base for astrochemistry are calculated, compared with experimental data, and represented in the format k_cap(T) ≈ c₁ + c₂(T/300 K)^−1/2. The parameters c₁ and c₂ can be predicted in a very simple way. The approach allows one to identify capture-controlled mechanisms and/or to trace experimental artifacts. The approach applies equally well to the capture of symmetric top and linear dipole molecules by arbitrary ions.     

Comparison of “bottom-up” and “top-down” strategies for the estimation of the uncertainty in organic elemental analysis

The estimation of uncertainty in organic elemental analysis for C, H, N and S is reported. Both “bottom up” and “top down” strategies are used for uncertainty calculations. The bottom up approach used the results of C, H, N, and S obtained from the homogeneity study of two pure chemicals (toluene-4-sulfonamide and 4(6)-methyl-2-thiouracil). Two calibration systems, K factor and calibration curve, were applied in this study and no significant differences were obtained. For the “top down” approach, we used the data obtained from a proficiency test on both pure chemicals from among 45 Spanish laboratories. Both approaches are compared and discussed below.     

Crystal Growth Of Mixed Titanium Sillenites

Top Seeded Solution Growth (TSSG) technique has been used to produce Bi₁₂TiO₂₀ (BTO) and some mixed Bi₁₂Ti_0.8M_0.2O₂₀ single crystals in which Ti was substituted with M=V, Pb or Ga. Pure Bi₄₀Ga₂O₆₃ (BGaO) single crystals have been grown, too. Thermal conditions enabling growth of uniform [110] sillenite single crystals with totally flat (110) interface have been found. Influence of composition on spectral characteristics of the BTO mixed crystals has been investigated.     

管范畴中的模同态与模分解

本讨论管范畴（ｔｕｂｅ）中的模同态。在不可分解模上定义特殊生成元,并运用它研究了管范畴中模同态的一些性质,得到了关于同态ｆ：Ｍｈ,ｌ→Ｌ的导出的模Ｌ的直和分解及其余核的构造。     

信息与计算科学专业应用型人才培养模式的研究

分析了信息与计算科学专业课程教学的特点和存在的教与学的矛盾.并以《高等代数》为试点,在教学实践中试行教学改革,积极探索教学与实际相结合与计算机信息有机结合的教学模式,在应用型人才培养方面取得显著成效.对信息与计算科学专业应用型人才培养有一定的借鉴作用.     

一二课堂协同培养卓越化学教师和化学拔尖人才——北京师范大学化学学院一二课堂协同育人机制创新探究

北京师范大学化学学院坚持教书与育人相统一,认真贯彻落实全员全过程全方位育人要求,立足学科特点,围绕立德树人重要任务,以人才培养实际需求为核心,以改革第二课堂培养模式为重点,不断加强第二课堂科学化建设,着力推动第一、第二课堂在形式、内容、师资等方面互通、互补、互融,探索2个课堂协同合力育人新路径,有力提升了培养卓越化学教师和化学拔尖人才的育人实效。     

Small visible energy scalar top iterative discriminant analysis

Light scalar top quarks with a small mass difference with respect to the neutralino mass are of particular cosmological interest. This study uses an iterative discriminant analysis method to optimize the expected selection efficiency at the international linear collider (ILC).      

Coarse-grained description ofq-deformation top and t-j model

From RTT relations the integrable Hamiltonian of the trigonometric Goryachev-Chaplygin gyrostat is established, which can be reduced to the Hamiltonian of t-j model by using multi-fermion realization ofSU _q(2) algebra and average-field approximation. Project supported in part by the National Natural Science Foundation of China (Grant No. 19377102).     

Systems of <Emphasis Type="Italic">sl</Emphasis>(2, ℂ) tops as two-particle systems

We show that Euler-Arnold tops on the algebra sl(2, ℂ) are equivalent to a two-particle system of Calogero type. We show that an arbitrary quadratic Hamiltonian of an sl(2, ℂ) top can be reduced to one of the three canonical Hamiltonians using the automorphism group of the algebra. For each canonical Hamiltonian, we obtain the corresponding two-particle system and write the bosonization formulas for the coadjoint orbits explicitly. We discuss the relation of the obtained formulas to nondynamical Antonov-Zabrodin-Hasegawa R-matrices for Calogero-Sutherland systems. __________ Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 157, No. 1, pp. 8–21, October, 2008.