On the first passage times of reflected O-U processes with two-sided barriers

In this article, we give the Laplace transform of the first passage times of reflected Ornstein-Uhlenbeck process with two-sided barriers. AMS Subject Classifications 60H10 · 60G40 · 90B05 Supported by NSF of China.     

降膜结晶过程的数值模拟

本文采用数值方法对在工业上有着广泛应用前景的降膜结晶分离过程进行了模拟，提出了一套描述降膜结晶过程的降膜流动、传热、传质及结晶相变相互耦合的以控制容积为基础的有限差分的湍流数值计算模型和算法。本模型的计算结果与以前简化模型的计算结果相比，更符合实验值．     

Production and identification of new neutron-deficient isotope235Am in region of transuranium

A new transuranium neutron-deficient isotope²³⁵Am was produced by 35 MeV proton to bombard the rare radioactive²³⁸Pu target. The products were transported and collected by the He-jet system. The Am isotopes were separated and purified by radiochemistry method and the y-ray, X-ray and y-X(y) coincidence of the samples was measured. The synthesis of²³⁵Am was definitely identified. Its measured half-life is (15±5) min. Project supported by the National Natural Science Foundation of China and the Chinese Academy of Sciences.     

大麦应用三十烷醇磷酸酯钾田间试验初报

田间喷施 0. 01mg/L 的三十烷醇磷酸酯钾或 0. 5mg/L 的三十烷醇都能显著改善同源四倍体大麦的 产量性状且改善的程度相当,使穗颈长度从 2. 4cm 延长到 3. 7cm, 减少包颈的发生率, 穗重从 1. 145g 提 高到 1. 338g,结实率从 75. 0%提高到 79. 5%, 千粒重从 43. 638g 增加到 50. 031g.     

A New Synthesis Method and Crystal Structure of 2-Phenyl-5,6,7,8-tetrahydro-6,6-dimethyl-5,7-methano-8-quinolinol

The title compound 2-phenyl,5,6,7,8-tetrahydro-6,6-dimethyl-5,7-methano-8- quinolinol 1 has been synthesized by the oxidation of corresponding anion with 02. The oxidation gave a convenient method for synthesizing pyridylalcohol 1 in good yield. The suitable single crystals for X-ray diffraction were obtained by recrystallization from a mixture of solvents （ether and ethyl acetate）. The configuration of C6 in the title compound is in R form and there are strong face-to-face offset π-π interactions between pyridine rings. Crystallographic data for 1： C18H19NO, Mr = 265.34, monoclinic, space group P21/c with a = 13,4073（4）, b = 10.2866（3）, c = 10,5570（3）A, β = 108.413（2）°, V = 1381.43（7） A^3, Z = 4, De= 1.276 g/cm^3, μ = 0.078 mml, F（000） = 568, R = 0.0721 and wR = 0.2054 for 2241 observed reflections （I〉 2σ（I））.     

Ru原子高Rydberg态研究

本文描述用激光共振激发-场电离实验方法测定Ru原子的4d⁷(⁴F)ns(n=28—45)和4d⁷(⁴F)nd(n=26—48)系列Rydberg能级,并应用非线性拟合得到了Ru原子的第一电离阈值。采用相对论性自洽场方法对所得能级以及相应的量子亏损作了计算,理论与实验结果符合得很好。此外还将本文所得的第一电离阈值与已有数据作了比较。 关键词：     

Pd diffusion on MgO(1 0 0): The role of defects and small cluster mobility

Density functional theory is used to explore the energy landscape of Pd atoms adsorbed on the terrace of MgO(1 0 0) and at oxygen vacancy sites. Saddle point finding methods reveal that small Pd clusters diffuse on the terrace in interesting ways. The monomer and dimer diffuse via single atom hops between oxygen sites with barriers of 0.34 eV and 0.43 eV respectively. The trimer and tetramer, however, form 3D clusters by overcoming a 2D-3D transition barrier of less than 60 meV. The trimer diffuses along the surface either by a walking or flipping motion, with comparable barriers of ca. 0.5 eV. The tetramer rolls along the terrace with a lower barrier of 0.42 eV. Soft rotational modes at the saddle point lead to an anomalously high prefactor of 1.3 × 10¹⁴ s⁻¹ for tetramer diffusion. This prefactor is two order of magnitude higher than for monomer diffusion, making the tetramer the fastest diffusing species on the terrace at all temperatures for which diffusion is active (above 200 K). Neutral oxygen vacancy sites are found to bind Pd monomers with a 2.63 eV stronger binding energy than the terrace. A second Pd atom, however, binds to this trapped monomer with a smaller energy of 0.56 eV, so that dimers at defects dissociate on a time scale of milliseconds at room temperature. Larger clusters bind more strongly at defects. Trimers and tetramers dissociate from monomer-bound-defects at elevated temperatures of ca. 600 K. These species are also mobile on the terrace, suggesting they are important for the ripening observed at ?600 K during Pd vapor deposition on MgO(1 0 0) by Haas et al. [G. Haas, A. Menck, H. Brune, J.V. Barth, J.A. Venables, K. Kern, Phys. Rev. B 61 (2000) 11105].     

简并基态最陡下降微扰理论

本文证明,Cioslowski所引入的一个全新的量子力学计算方案,非简并基态最陡下降微扰理论,通过按对称性选择合适的零级试探波函数后,可以处理简并基态的微扰分裂问题由于最陡下降微扰理论既避免了通常的其他微扰理论需要对各个基矢量无限求和的或求解一组微分方程的缺陷,又具有逐步迭代改善计算结果的优点,本文引进的计算方案可望在原子分子及其他多粒子体系能级的微扰分裂计算中得到广泛应用。 关键词：     

质子交换LiNbO3晶体的光谱特性与抗光折变机理的研究

测量了质子交换LiNbO₃,波导层的红外光谱和光电导.实验结果表明,它们抗光折变能力的提高所造成的是其光电导比纯LiNbO₃,晶体高5—10倍. 关键词：     

聚乙二醇-硫酸铵-水双水相体系萃取测定银杏叶中芦丁的含量

建立芦丁在PEG1000，PEG1500-(NH4)2SO4-H2O双水相体系中的萃取测定方法。在PEG1000，PEG1500为3．0mL，(NH4)2SO4用量为2．5g，pH6．0B．R缓冲液的最佳萃取条件下，用紫外分光光度法直接测定银杏叶提取液中的芦丁含量。实验结果表明：方法的相对标准偏差分别为2．1％，1．8％(n=7)。样品加入回收率分别为101．1％，94．7％。方法具有良好的重现性、选择性。