Prompt neutrino results from a proton beam dump experiment

A study of prompt neutrino events from 400 GeV protons on a beam-dump is presented. The ratio of electron- to muon-neutrino rates is 0.86±0.14, in agreement withe– universality. The anti-neutrino to neutrino flux ratio is . The absolute rates and distributions observed are shown to be in quantitative agreement with the known properties of charmedquark production in hadron collisions.Supported by the Bundesministerium für Forschung und Technologic, Bonn, FRG     

Langmuir-blodgett films of hydroxamic acid of the quinoxalinone series

Amphiphilic hydroxamic acid 2-(4-decyloxyphenyl)-4-hydroxy-3-oxo-3,4-dihydroquinoxalin-1-oxide was synthesized. The conditions of the formation of hydroxamic acid and its lead, europium, cadmium, and copper salt monomolecular layers were studied. Multimolecular systems were prepared by the Langmuir-Blodgett method from various solvents, including chloroform, carbon tetrachloride, and toluene. The films were characterized by small angle X-ray scattering, UV and IR spectroscopy, ellipsometry, and atomic-force microscopy. The UV data and monolayer compression isotherms showed changes in the state of hydroxamic acid in various solvents in the presence of light and in the dark. The suggestion was made that changes in solutions were related to aggregation phenomenon. Original Russian Text ? T.A. Duda, L.L. Sveshnikova, V.K. Khlestkin, K.A. Dembo, L.G. Yanusova, 2009, published in Zhurnal Fizicheskoi Khimii, 2009, Vol. 83, No. 4, pp. 758–764.     

Second-order ferroic properties of a Pb5Ge3O11 uniaxial ferroelectric

The ferrobielastic properties (ferroic properties of the second order) earlier theoretically predicted for lead germanate uniaxial ferroelectric crystals are justified experimentally. It is demonstrated that single-domain samples are formed upon cooling to temperatures below the Curie point under uniaxial mechanical stresses corresponding to a combination of mechanical stresses σ₁₁σ₁₃ or σ₂₂σ₂₃. The macroscopic mechanism of this phenomenon is considered.     

基于粗糙近似的Web事务聚类改进算法

针对现有Web使用记录挖掘方法发现的知识和规则存在不精确或不完全的问题,提出了一种改进的基于粗糙近似的Web事务聚类算法.该算法首先对原有算法得到的每个类,用关系矩阵找出在这个类中不满足传递性的对象,然后在该对象的集合(类)上用关系矩阵找出在这个类中不满足传递性的对象,再对每个类进行分割,使其满足关系R的传递性,克服了现有算法不满足关系的传递性和在某些情况下得到的结果不准确的缺点.     

Electronic excitation energy transfer between CdS quantum dots and carbon nanotubes

Stationary and transient photoluminescence of CdS quantum dots deposited on silicon substrates and carbon nanotubes is investigated. The photoluminescence spectrum of quantum dots on a silicon substrate is dominated by a band originating from electron transitions between the quantum-confinement levels in the dots. When the quantum dots are deposited on carbon nanotubes, the intensity of this band decreases significantly. Furthermore, the kinetics of the photoluminescence decay becomes faster, which brings evidence of an additional channel for the quantum-dot deexcitation. The analysis of the experimental data demonstrates that the Förster energy transfer from CdS quantum dots to carbon nanotubes is most probably responsible for this channel. The efficiency of this process exceeds 60%.     

A consistent and stabilized continuous/discontinuous Galerkin method for fourth-order incompressible flow problems

This paper presents a new consistent and stabilized finite-element formulation for fourth-order incompressible flow problems. The formulation is based on the C⁰-interior penalty method, the Galerkin least-square (GLS) scheme, which assures that the formulation is weakly coercive for spaces that fail to satisfy the inf-sup condition, and considers discontinuous pressure interpolations. A stability analysis through a lemma establishes that the proposed formulation satisfies the inf-sup condition, thus confirming the robustness of the method. This lemma indicates that, at the element level, there exists an optimal or quasi-optimal GLS stability parameter that depends on the polynomial degree used to interpolate the velocity and pressure fields, the geometry of the finite element, and the fluid viscosity term. Numerical experiments are carried out to illustrate the ability of the formulation to deal with arbitrary interpolations for velocity and pressure, and to stabilize large pressure gradients.