A model study of the laser-induced stabilization of a collision complex

The possibility of stabilizing a collision complex by stimulated emmission with coherent radiation is explored for a model. three-atom system. The lifetimes of several resonance states of this system were obtained previously and are used in a simple two-level model to describe the interaction of radiation with a resonance state and a true bound state. For the case where the energy difference between the two levels is time independent, simple, analytical expressions are used to obtain the time-dependent transition probability. Numerical solutions are obtained for the more realistic case where this energy difference is time dependent. For both cases, a substantial transition probability for stabilization is calculated for moderate laser intensities (e.g. 8.1 kW/cm² for an assumed dipole matrix element of 0.01 D).     

Matrix isolation study of S2O6F2 pyrolysis products: The infrared spectrum of SO3F radical

Infrared and visible absorption spectra of the low pressure heated products of S₂O₆F₂ trapped in inert gas matrices at 14 K are presented. The following have been identified as major infrared-absorbing species: SO₃F, SO₃, HSO₃F, and S₂O₆F₂, with matrix spectra of the latter three unequivocally confirming their presence. Reasonable reactions accounting for the production of these species are proposed, and a reassignment of the fundamental vibrations of monomeric HSO₃F is offered. The infrared absorptions of the SO₈F radical have been observed for the first time, and the six fundamental vibrations determined. These frequencies are in good accord with earlier values deduced indirectly by King and Warren from hot band transitions in the visible absorption spectrum of the vapor. This same visible system (${}^2\text{E}\text{-}\text{X}\text{?}{}^2\text{A}{}_2$) has also been observed here for the matrix isolated species.     

烟草(Nicotiana tabacum)原生质体再生成植株及影响植株分化的某些因素

从烟草(品种革新一号)单倍体花粉植株的叶和茎产生的愈伤组织,结合悬浮培养,获得的细胞分离出原生质体。在液体培养基中静置培养,12小时后原生质体开始变为卵圆形,细胞壁明显可见,24小时后完成第一次细胞分裂。以后继续分裂形成浅黄色的愈伤组织,在培养四星期后可达1毫米大小,再放到转床上进行旋转培养18天左右,愈伤组织可达3—4毫米大小。当转移到分化培养基后,分别分化出苗及根,长成完整的植株。 原生质体再生细胞的分裂与分化,不仅受不同器官来源的愈伤组织及其年龄的影响;还受分化培养基的基本成份及所用细胞分裂素的类型等的影响。     

A comparison of visualization of Stokes flow in a V-shaped and rectangular channel

A comparative study of visualization of Stokes flow induced by rotation of a circular cylinder in a V-shaped and rectangular channel was performed. The visualization was carried out using solid tracers of magnesium. Some quantitative data were deduced from visualization photographs and a comparison was made.     

微透析液中葡萄糖的液相色谱—电化学测定

文介绍了一种灵敏测定大白鼠皮下微透析液中葡萄糖的液相色谱－电化学分析方法。本法用柱后葡萄糖氧化酶反应器将色谱分析柱中分离出的葡萄糖转化成过氧化氢，再用过氧化物酶电极检测生成的过氧化氢。     

Isogroups of differential ideals of vector-valued differential forms: Application to partial differential equations

An older geometric technique for the study of invariance groups of partial differential equations, originally proposed by one of the authors and F. B. Estabrook, is generalized and extended to problems involving exterior equations for vector-valued or Lie algebra-valued exterior differential forms. Use of the method is demonstrated in the study of the symmetry groups of the two-dimensional Dirac equation and the full Yang-Mills free-field equations in Minkowski spacetime.     

Ba(SCN)2(H2O) complex of the cis-syn-cis isomer of 2,5,8,15,18,21-hexaoxatricyclo[20,4,0,09,14]hexacosane(dicyclohexyl-18-crown-6) [Ba(SCN)2(H2O)(C20H36O6)]

The structure of the title compound has been redetermined. Hydrogenation of dibenzo-18-crown-6 yields two conformational isomers which were proposed to be the cis-syn-cis and the cis-trans-cis isomers of dicyclohexyl-18-crown-6. The previous study had established that the title complex contains the ligand which has the cis-syn-cis conformation but had resulted in some inaccurate bond lengths and also in an uncertainty regarding the presence of a water of hydration in the crystal. This study confirmed the report of the general conformation of the complex, resulted in more precise bond lengths and clearly established that a water of hydration was present at the crystal.     

Energy levels of 92Nb and 94Tc from 92Zr, 94Mo(p,nγ)92Nb, 94Tc

The γ-decays of the energy levels of ⁹²Nb and ⁹⁴Tc were measured following the ⁹²Zr(p, n)⁹²Nb and ⁹⁴Mo(p, n)⁹⁴Tc reactions. For ⁹²Nb the γ-ray thresholds were measured and a detailed excitation function was obtained near the ⁹³Zr ground-state isobaric analog resonance. Also, γ-γ coincidence measurements with two Ge(Li) detectors were made for both ⁹²Nb and ⁹⁴Tc. The coincidence measurements determined ten energy levels in ⁹²Nb and two levels in ⁹⁴Tc. A comparison with particle transfer reactions is used to elucidate the structure of ⁹²Nb levels observed here but not seen in the transfer reactions.     

叶轮机械设计自变数在内外环壁面上的限制条件及轴流式叶轮机械S1流面的翘曲

本文利用中心流面法的概念,指出叶轮机械的设计白变数在内、外环壁面上应有附加的限制条件,并导得其具体简明方程。同时,还定性地分析了S₁流面的翘曲情况。