诱导效应指数与XSiRxH3—x的标准生成热

诱导效应指数与ＸＳｉＲｘＨ３－ｘ的标准生成热张秀利（河北轻化工学院基础部石家庄０５００１８）关键词诱导效应指数标准生成热键裂能烷基硅衍生物对于含硅有机物的标准生成热大多未见报导［１－２］，本文将利用诱导效应指数Ｉ［３，４］，作为参数，建立一套简单而准...     

ε－次可微多目标规划的最优性条件

本文主要从多目标规划相应的加权问题出发，讨论了在ε－次可微的条件下，凸多目标规划问题η－有效解存在的必要条件与充分条件．     

Nonlinear Galerkin methods and mixed finite elements: two-grid algorithms for the Navier-Stokes equations

Summary. A nonlinear Galerkin method using mixed finite elements is presented for the two-dimensional incompressible Navier-Stokes equations. The scheme is based on two finite element spaces and for the approximation of the velocity, defined respectively on one coarse grid with grid size and one fine grid with grid size and one finite element space for the approximation of the pressure. Nonlinearity and time dependence are both treated on the coarse space. We prove that the difference between the new nonlinear Galerkin method and the standard Galerkin solution is of the order of $H^2$, both in velocity ( and pressure norm). We also discuss a penalized version of our algorithm which enjoys similar properties. Received October 5, 1993 / Revised version received November 29, 1993     

A metastable flame-front interface and Carrier''s problem

Metastable dynamics for a nonlocal PDE modeling the upwards propagation of a flame-front interface in a vertical channel is analyzed in the one-dimensional case where the channel cross-section is taken to be the slab -1<x<1. In a certain asymptotic limit, the interface assumes a roughly concave parabolic shape, and the tip of the parabola drifts asymptotically exponentially slowly towards the boundary of the domain. In contrast to previous analyses that studied this behavior by transforming the governing nonlocal PDE to a convection–diffusion equation, a novel nonlinear transformation is introduced that transforms the problem to a singularly perturbed quasilinear PDE. The steady-state problem for this transformed PDE, for which the parabolic interface shape maps onto a one-spike solution, is closely related to a class of two-point boundary value problems with seemingly spurious solutions studied initially by G. Carrier in 1968. Rigorous and formal asymptotic results for a one-spike solution to this transformed PDE are obtained together with a formal metastability analysis of certain time-dependent solutions.     

High-energy scale revival and giant kink in the dispersion of a cuprate superconductor

In the present photoemission study of a cuprate superconductor Bi1.74Pb0.38Sr1.88CuO6+delta, we discovered a large scale dispersion of the lowest band, which unexpectedly follows the band structure calculation very well. Similar behavior observed in blue bronze and the Mott insulator Ca2CuO2Cl2 suggests that the origin of hopping-dominated dispersion in an overdoped cuprate might be quite complicated. A giant kink in the dispersion is observed, and the complete self-energy containing all interaction information is extracted for a doped cuprate. These results recovered significant missing pieces in our current understanding of the electronic structure of cuprates.     

A New Method for Establishing Pseudo Orthogonal Properties of Eigenfunction Expansion Form in Fracture Mechanics

A new and simple method is developed to establish the pseudo orthogonal properties (POP) of the eigenfunction expansion form (EEF) of crack-tip stress complex potential functions for cracked anisotropic and piezoelectric materials, respectively. Di?erent from previous research, the complex argument separation technique is not required so that cumbersome manipulations are avoided. Moreover, it is shown, di?erent from the previous research too, that the orthogonal …     

近场波动模拟的一种应力人工边界

采用平面波和远场散射波混合透射，引入无限介质线弹性本构关系建立了一种应力人工 边界条件. 其优点在于边界结点反应与内部有限元结点反应采用相同的积分格式计算，有限 元积分方法稳定时不存在人工边界失稳问题. 数值算例表明：边界精度高于现有黏性边 界、黏弹性人工边界，以及一、二阶透射人工边界.     

Green Approach to the Fabrication of Superhydrophobic Mesh Surface for Oil/Water Separation

We report a simple and environment friendly method to fabricate superhydrophobic metallic mesh surfaces for oil/water separation. The obtained mesh surface exhibits superhydrophobicity and superoleophilicity after it was dried in an oven at 200 °C for 10 min. A rough silver layer is formed on the mesh surface after immersion, and the spontaneous adsorption of airborne carbon contaminants on the silver surface lower the surface free energy of the mesh. No low‐surface‐energy reagents and/or volatile organic solvents are used. In addition, we demonstrate that by using the mesh box, oils can be separated and collected from the surface of water repeatedly, and that high separation efficiencies of larger than 92 % are retained for various oils. Moreover, the superhydrophobic mesh also possesses excellent corrosion resistance and thermal stability. Hence, these superhydrophobic meshes might be good candidates for the practical separation of oil from the surface of water.     

Molecularly imprinted polymers with synthetic dummy templates for the preparation of capsaicin and dihydrocapsaicin from chili peppers

In this work, dummy molecularly imprinted polymers with high selectivity and affinity to capsaicin and dihydrocapsaicin are designed using N‐vanillylnonanamide as a dummy template. The performance of dummy molecularly imprinted polymers and nonimprinted polymers was evaluated using adsorption isotherms, adsorption kinetics, and selective recognition capacity. Dummy molecularly imprinted polymers were found to exhibit good site accessibility, taking just 20 min to achieve adsorption equilibrium; they were also highly selective toward capsaicin and dihydrocapsaicin. We successfully used dummy molecularly imprinted polymers as a specific sorbent for selectively enriching capsaicin and dihydrocapsaicin from chili pepper samples. In a scaled‐up experiment, the selective recovery of capsaicinoids was calculated to be 77.8% using solid‐phase extraction. To the best of our knowledge, this is the first example of the use of N‐vanillylnonanamide as a dummy template in molecularly imprinted polymers to simultaneously enrich capsaicin and dihydrocapsaicin.