On the use of Galerkin-Eckhaus method to study the nonlinear regime of Marangoni-Bénard instabilities in an evaporating liquid layer

We investigate theoretically Marangoni-Bénard instability in an evaporating liquid layer surmounted by its vapor and an inert gas. A Galerkin-Eckhaus method, based on a slaving principle and an iterative algorithm, and a direct finite element method are used to determine the evaporation rate above the convective threshold. Both methods provide precise quantitative results, even far from the linear stability threshold.     

Graded quasi-Lie algebras

This paper is concerned with a new class of graded algebras naturally uniting within a single framework various deformations of the Witt, Virasoro and other Lie algebras based on twisted and deformed derivations, as well as color Lie algebras and Lie superalgebras. Presented at the International Colloquium “Integrable Systems and Quantum Symmetries”, Prague, 16–18 June 2005. Supported by the Liegrits network Supported by the Crafoord foundation     

Electrochemical reduction of Ru(η-arene)(κ-tris(pyrazolyl)methane) dicationic complexes

One-electron reduction of [Ru(η⁶-arene)(κ³-HCPz₃)]²⁺ complexes (arene = p-xylene, p-cymene, or hexamethylbenzene, Pz = pyrazolyl) was observed at approximately −1.4 V vs. ferrocene in nonaqueous media. Cyclic voltammetry data showed no direct evidence of a hapticity change for either the arene or the tris(pyrazolyl)methane (TPM) ligand in the electron-transfer step. The resulting 19-electron radicals underwent reactions at the arene, giving persistent cyclohexadienyl ruthenium complexes which could be oxidized back to the original complex in an overall chemically reversible process. The dominant reaction for the hexamethylbenzene-containing radical was shown to be an arene-based dimerization (k_dim = 4 (±3) × 10³ M⁻¹ s⁻¹) which occurs in competition with an H-atom capture, most likely from solvent. The behavior of the 19-electron radicals is similar to that of their all-carbocyclic mixed-sandwich analogues Ru(arene)(C₅R₅) [O.V. Gusev, M.A. Ievlev, T.A. Peganova, M.G. Peterleitner, P.V. Petrovskii, Y.F. Oprunenko, N.A. Ustynyuk, J. Organomet. Chem. 551 (1998) 93].     

基于3S的塔里木河中游景观格局变化特征分析

景观格局变化研究,是目前景观生态学的研究热点.本文把生态环境脆弱与人类活动的影响比较强烈的塔里木河中游选为研究靶区,利用遥感的手段获取试验区1973、1992和2000年景观格局的基础数据,在3S技术和景观生态学方法支持下,对塔里木河中游近30年土地利用和景观结构的时空变化特征进行了研究,对该地区的开发利用和生态环境保护提供科学依据.     

Mesons and diquarks in a dense quark medium with color superconductivity

In the framework of the Nambu-Jona-Lasinio model with two quark flavors, we investigate the spectrum of meson and diquark excitations of dense quark matter in the phase with color superconductivity. The color SU_c(3) symmetry is spontaneously broken to SU_c(2) in this phase. But instead of the expected five Goldstone bosons in the mass spectrum, we observe only three, among which two bosons obey the quadratic dispersion law. We find the doublet of light diquark states with the mass ∼ 15 MeV and also the heavy diquark resonance (SU_c(2) singlet) with the mass ∼ 1100 MeV. The π-and σ-mesons have the mass ∼ 330 Mev in the phase with color superconductivity. The π-mesons are then stable particles, while the σ-meson is stable only in the chiral limit in which the current quark mass m₀ becomes zero. If m₀ ≠ 0, then the σ-meson mixes with diquarks in the phase with color superconductivity and becomes a resonance with the width ∼ 30 MeV. __________ Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 150, No. 1, pp. 95–111, January, 2007.     

钨酸铅晶体中与铅空位有关的电子结构和色心模型研究

根据密度泛函理论对钨酸铅晶体中铅空位周围的晶格进行了结构优化，计算得到铅空位周围的晶格结构、电子态密度分布和偏振吸收光谱；计算结果表明钨酸铅晶体中铅空位的两价负电性是通过铅空位周围的氧共同抓获两个空穴来维持局部电中性的，即铅空位周围形成的色心模型为［O₂^3--V_Pb^2--O₂^3-］，不同的氧离子抓获空穴方式不同形成不同的色心，对应不同的吸收带；根据吸收带的偏振性质，提出了各个 关键词： 钨酸铅晶体 色心模型 电子结构 偏振特性     

三维测量中空间编码技术的研究

针对三维测量中的关键技术——空间编码技术，介绍了空间编码技术对测量的精度、速度和可靠性方面所起的重要作用。阐述了基于三角法结构光投影的测量原理。对空间编码技术在三维测量中的功能进行了研究，介绍了编码原理，总结了编码方案所应满足的条件。列举了当前典型的几种编码方案和一种新的条纹边界编码方案，并对它们进行了分析和比较，指出了它们各自的优缺点和发展趋势。在此研究基础上对空间编码技术作了进一步的总结，指出该领域未来的发展方向将是彩色编码与已有编码的结合。     

几种颜色测量方法的比较

本文回顾了颜色测量的历史，分析比较了目视法、光电积分法和分光光度法三类颜色测量方法，重点阐述了目前最先进的测色方法——光电摄谱法。简述了目前国内外测色仪器的产品现状，展望了仪器测色的发展趋势。     

平面图的循环色数及临界性

循环着色是普通着色的推广．本文中,我们研究了一类平面图-“花图”的循环着色问题,证明了由2r 1个长为2n 1的圈构成的“辐路”长度为m的花图Fr,m,n的循环色数是2 1/(n-m/2),并证明了在这类图中去掉任何一个点或边后,循环色数都严格减少但普通色数不减少,即这类图是循环色临界的但不是普通色临界的．同时,我们还研究了循环着色与图Gkd中的链之间的关系,给出了两个等价的条件．