Skew-Hermitian Triangular Splitting Iteration Methods for Non-Hermitian Positive Definite Linear Systems of Strong Skew-Hermitian Parts

By further generalizing the skew-symmetric triangular splitting iteration method studied by Krukier, Chikina and Belokon (Applied Numerical Mathematics, 41 (2002), pp. 89–105), in this paper, we present a new iteration scheme, called the modified skew-Hermitian triangular splitting iteration method, for solving the strongly non-Hermitian systems of linear equations with positive definite coefficient matrices. We discuss the convergence property and the optimal parameters of this new method in depth. Moreover, when it is applied to precondition the Krylov subspace methods like GMRES, the preconditioning property of the modified skew-Hermitian triangular splitting iteration is analyzed in detail. Numerical results show that, as both solver and preconditioner, the modified skew-Hermitian triangular splitting iteration method is very effective for solving large sparse positive definite systems of linear equations of strong skew-Hermitian parts.     

Design of an experimental procedure for energy evaluation from biomass

The rational and sustainable exploitation of nature resources is one of the priority objectives of our society. In this article a method is proposed to evaluate and exploit the energetic resources contained in different forest formations. This method is based on the use of a combustion bomb calorimeter to determine the calorific values of the different samples studied. These results were complemented with chemical analysis of the samples and with environmental and geomorphological studies of the zones were samples were taken. The results obtained during the last 3 years for the residual biomass originated from the forest formations existing in Galicia ensure the reliability and usefulness of the method that can be extended to any forest formation all over the world.     

Generalized lattice model of liquid state and its relation to Ginzburg–Landau theory

Basic principles of the generalized lattice model of multicomponent condensed systems are formulated. Short-range parts of interatomic interactions are taken into account by means of the geometric constraints method. Long-range parts of the interactions are taken into account in mean field approximation. The expression for Helmholtz free energy is obtained. A system of integral equations for the equilibrium distributions of components is derived. The asymptotic properties of its solutions are investigated. Moment expansion of interatomic interactions and localization of integral terms in free energy is obtained. A Ginzburg–Landau-like functional of free energy is derived.     

Structure and electrochemical behaviour of 4,7-diazaheptyl-trimethoxy-silane and vinyl-trialkoxy-silane adsorbed at silver surface

Novel self-assembled monolayers were obtained on silver using 4,7-diazaheptyl-trimethoxy-silane (SiN) and vinyl-trialkoxy-silane (SiVA, where the alkyl group is 3,6,9,12,15,18,21,24,27,30,33,36,39,42,45,48,51,54,57,60-eicozaoxa- hexaheptaconan). It was shown that thus modified metal surface was protected against electrooxidation. A densely packed monolayer remained stable and did not desorb from the Ag electrode on the potential cycling. The structure of SiN and SiVA as well as their complexes with Li⁺ cations were calculated and visualised by the AM1d and PM5 semi-empirical methods.     

Phenylene dendrimers and novel hyperbranched polyphenylenes as light emissive materials for blue OLEDs

New materials based on low-generation polyphenylene dendrimers with the light emission in the blue spectrum range were synthesized and examined for an efficient organic light emitting diodes (OLED) application. It has been shown that the ratio of p-phenylene groups with high fluorescence parameters to 1,3,5-triphenylbenzene groups with low fluorescent parameters may be the possible reason for the experimental variations of relative quantum yield of photoluminescence in the compounds explored. The quantum yield value is increased with a number of dendrimer generations up to 50–70%. The role of bromine atoms as the luminescence quenchers have been demonstrated, which is important for synthesis route choice.     

广义Sierpinski集

本文考察了包括平面上的各种广义 Cantor集 ,Sierpinski集和包括某些连续不可微曲线在内的广义 Sierpinski集 .由相似变换 ,导出了它们的级数表达式 ,并利用它和字符串空间的对应关系 ,计算出它们的Hausdorff维数     

Ultraslow phonon-assisted collapse of tubular image states

We predict ultraslow collapse of “tubular image states” (TIS) on material surfaces. TIS are bound Rydberg-like electronic states formed at large distances (∼30 nm) from the surfaces of suspended circularly-symmetric nanowires, such as metallic C nanotubes. The states are formed in potential wells, resulting from a combination of the TIS-electron attraction to image charges in the nanotube and its centrifugal repulsion, caused by spinning around the tube. We demonstrate that TIS can collapse on the tube surface by passing their angular momentum l to circularly polarized flexural phonons excited in the tube. Our analysis shows that for highly detached TIS with l ? 6 the relaxation lifetimes are of the order of 10 ns-1 μs, while for l < 6 these lifetimes are reduced by several orders of magnitude.     

中国延边朝鲜族自治州的移民资本流动

显著的移民资本流动已经在南朝鲜与延边之间发生。延边当地政府支持劳动力移民,支持随后的汇款额利用所带来的渐进利益。官方对成功的移民者和他们同延边经济发展的整合不感兴趣。他们已经采取措施推动移民但是并没有出台有效的政策用以将新资本转移到延边,并将它们注入当地发展中。到目前为止重要的资源并没有被触及。     

数据库原理及应用课程教学模式的研究与实践

本文针对目前数据库原理及应用课程在教学过程中存在的一些问题,探讨了如何从教学内容、教学目标、教学手段、教学方法以及考核方式上改进教学模式,从而提高学生的综合素质。     

微型圆热管挤压犁削／拔拉成型刀具和模具的设计

在分析微型热管的功能、技术要求及其加工工艺的基础上，设计了微型热管犁削-拔拉用成型刀具和系列模具．该刀具可使定位装夹方便，加工的热管直径尺寸稳定；模具保证了热管的外径尺寸并可方便地根据要求改变外径尺寸，热管外表面质量好，内部具有更加优良的毛细结构．刀具采用高速钢，模具采用45钢．