A Class of Nonlinear Singularly Perturbed Problems of Fourth Order

ConsiderthefollowingnonlinearboundaryvalueproblemwhereEisasmallpositiveparameter,f,Warecontinuouspartialderivativefunctionsregardingtheirvariablesincorrespondenceranges,andfisasecondordercontinuouspartialderivativeaboutu(3).MoJiaqiconsideredaseriesofsingularlyperturbednonlinearproblemsusingthe.differentialinequalitytheory['J-['J.Mo[9Jandothers[3Jstudiedthesingularlyperturbedprob-lemsoffourthorder.Assumethat(I)Thereducedproblemof(1)-(5)hasafourthordercontinuouspartialderivativesolutionU(x)o…     

THE SINGULARLY PERTURBED NONLOCAL BOUNDARY VALUE PROBLEMS FOR HIGHER ORDER NONLINEAR ELLIPTIC EQUATIONS

In this paper,a class of singular perturbation of noidocal boundary value problems forelliptic partial differentia[ equations of higher order is considered by using the differential in-equalities. The uniformly valid asymptotic expansion of solution is obtained.     

Preparation of core-shell magnetic Fe3O4@SiO2-dithiocarbamate nanoparticle and its application for the Ni2+, Cu2+ removal

A typical superparamagnetic nanoparticles-based dithiocarbamate absorbent (Fe₃O₄@SiO₂-DTC) with core-shell structure was applied for aqueous solution heavy metal ions Ni²⁺, Cu²⁺ removal.     

Knot Placement for B-Spline Curve Approximation via $L_{∞, 1}$-Norm and Differential Evolution Algorithm

In this paper, we consider the knot placement problem in B-spline curve approximation. A novel two-stage framework is proposed for addressing this problem. In the first step, the $l_{\infty, 1}$-norm model is introduced for the sparse selection of candidate knots from an initial knot vector. By this step, the knot number is determined. In the second step, knot positions are formulated into a nonlinear optimization problem and optimized by a global optimization algorithm — the differential evolution algorithm (DE). The candidate knots selected in the first step are served for initial values of the DE algorithm. Since the candidate knots provide a good guess of knot positions, the DE algorithm can quickly converge. One advantage of the proposed algorithm is that the knot number and knot positions are determined automatically. Compared with the current existing algorithms, the proposed algorithm finds approximations with smaller fitting error when the knot number is fixed in advance. Furthermore, the proposed algorithm is robust to noisy data and can handle with few data points. We illustrate with some examples and applications.     

Determination of 2,6-Dichlorophenol by Surface-Enhanced Raman Scattering with Molecular Imprinting

A novel method has been reported for 2,6-dichlorophenol using surface-enhanced Raman scattering (SERS). SiO₂/gold composites were selected as the SERS substrates to provide the response of gold nanoparticles. Molecular imprinting was subsequently used for the development of a specific detector to 2,6-dichlorophenol with precipitation polymerization. The molecularly imprinted polymer provided sensitive and selective SERS detection for the determination of 2,6-dichlorophenol. The intensity and concentration obeyed a linear relationship from 1?×?10^?5 to 1?×?10^?9?mol?L^?1 2,6-dichlorophenol. The sensitivity of SERS with the molecularly imprinted polymers provides a promising approach for practical analysis.     

生姜粉末组织过氧化氢传感器的研究

用生姜粉末组织作生物催化材料与氧电极结合制姜粉组织过氧化氢传感器，５．０×１０＾－５－２．０×１０＾－３ｍｏｌ／Ｌ范围内响应信号与过氧化氢浓度成正比，并与新鲜生姜组织电极和过氧化氢酶电极作对比，结果表明姜粉组织电极性能优良，且酶源容易获得和保存。     

膦、胂叶立德的化学与应用——Ⅱ.甲氧羰基亚甲基三苯基膦与2-全氟炔腈反应的研究

甲氧羰基亚甲基三苯基膦(1)与2-全氟炔腈(2)在常温下反应生成3和4的混合物,低温下(-78℃)反应仅生成4。对反应机理作了推测。     

生物电极的最新发展

生物电极是生物传感器最重要的一个分支，本文对近年来国内外有关生物电极的最新研究成果作一综述，并按生物膜材料、固定方法、换能器、应用及理论研究五部分加以分类。     

Long-time behavior of solutions to the derivative nonlinear Schrödinger equation for soliton-free initial data

The large-time behavior of solutions to the derivative nonlinear Schrödinger equation is established for initial conditions in some weighted Sobolev spaces under the assumption that the initial conditions do not support solitons. Our approach uses the inverse scattering setting and the nonlinear steepest descent method of Deift and Zhou as recast by Dieng and McLaughlin.