An ESR study of the acetaldehyde radical cation in freon matrices: Evidence for halogen superhyperfine interaction

The substructure associated with the doublet ESR spectrum of the acetaldehyde radical cation in Freon matrices below 100 K is shown to arise from a matrix interaction and not, as previously proposed, from coupling to the hydrogens of the methyl group. Since the reversible loss of this substructure at higher temperature is accompanied by almost no change in the large isotropic ¹H coupling(136 G) to the aldehydic hydrogen, the matrix perturbation appears to have a negligible effect on the spin distribution in the radical cation and is according interpreted as a superhyperfine interaction     

Light emission from porous silicon single and multiple cavities

Experimental and theoretical techniques are used to examine the effects of microstructuring on the optical properties of multilayer, single and multiple microcavity structures fabricated from porous silicon. Measurements of the reflectivity and photoluminescence spectra of three multilayer samples are presented. The results are modelled using a transfer matrix technique including a negative absorption term to represent the effect of spontaneous emission which gives luminescence. The emitted light is strongly controlled by the optical modes of the structures and very good agreement is observed between theory and experiment.     

Primary electron reflections in discharges surrounded by magnetic multipole walls

By observing the primary electron trajectories and studying experimentally the equilibrium of an argon plasma in the pressure range 0.8 × 10^?4 – 8 × 10^?4 torr, we show that the main effect of the surrounding magnetic wall is not the confinement of the plasma but the confinement of the primary electrons in the discharge.     

相对论性核碰撞中φ介子增强

用强子和弦级联模型LUCIAE系统地研究了相对论性p+p和Pb+Pb碰撞中φ介子产生.在模型框架内实验测得的158AGeV/cPb+Pb碰撞中φ介子产额相对于同能量p+p碰撞的增强现象,依赖于弦发射胶子的集体效应和奇异夸克压低约化两机制,在一定程度内能得到解释.     

在RHIC的极限碎裂和Ф介子产生(英文)

利用强子和串级联模型LUCIAE研究了PHOBOS的极限碎裂等以及在PHIC进行的Au +Au碰撞中带电粒子多重性的经验标度规律 .对介子的产生机制也通过与带电粒子多重性的比较进行类似的研究 .结果似乎表明在串级碎裂模型中带电粒子和介子有共同的产生机制 .还讨论了PHOBOS经验标度规律的模型依赖性 .     

Triangular actions onC 3

Free algebraic actions of a connected algebraic groupG onC ³ which can be triangularized are shown to be trivial, that isC ³ is equivariantly isomorphic toGxC ^3–dimG . This result follows directly from the case of the additive groupG=G _a and is shown to hold for quasi-algebraic actions as well. Connections with the classification of homogeneous affine varieties are discussed.Partially supported by NSF grant DMS 8420315     

Subdirect products of hereditary congruence lattices

A congruence lattice L of an algebra A is called power-hereditary if every 0-1 sublattice of Lⁿ is the congruence lattice of an algebra on Aⁿ for all positive integers n. Let A and B be finite algebras. We prove

Compressibility of copper via the self-consistent APW method

The self-consistent APW method was used in determining pressure as a function of volume for f.c.c. copper. The results are in excellent agreement in the range 0 to 600 kbar.