一类具非线性边值条件的微分方程的奇摄动问题

研究了一类非线性三阶微分方程的奇摄动问题.运用合成展开法构造了问题的形式渐近解,并运用不动点原理证明了原问题解的存在性及所得形式渐近解的一致有效性.     

一步法合成2,4-二硝基苯甲醚

以1-氯-2,4-二硝基苯（CDNB）为原料,不使用相转移催化剂,用KOH溶液为反应介质,一步合成了2,4-二硝基苯甲醚,其结构经¹H NMR, FT-IR和元素分析确证。最佳反应条件为：CDNB 0.20 mol, 30%KOH溶液为反应介质,甲醇100 mL,于55 ℃反应60 min,收率96.5%,纯度99.8%。     

The ground states and pseudospin textures of rotating two-component Bose–Einstein condensates trapped in harmonic plus quartic potential

The ground states of two-component miscible Bose–Einstein condensates(BECs) confined in a rotating annular trap are obtained by using the Thomas–Fermi(TF) approximation method.The ground state density distribution of the condensates experiences a transition from a disc shape to an annulus shape either when the angular frequency increases and the width and the center height of the trap are fixed,or when the width and the center height of the trap increase and the angular frequency is fixed.Meantime the numerical solutions of the ground states of the trapped two-component miscible BECs with the same condition are obtained by using imaginary-time propagation method.They are in good agreement with the solutions obtained by the TF approximation method.The ground states of the trapped two-component immiscible BECs are also given by using the imaginary-time propagation method.Furthermore,by introducing a normalized complex-valued spinor,three kinds of pseudospin textures of the BECs,i.e.,giant skyrmion,coaxial double-annulus skyrmion,and coaxial three-annulus skyrmion,are found.     

实时磁性测试深入理解锂离子电池中的过渡金属催化作用

催化剂由于具有降低电化学过电位和改善动力学条件的能力,在各种储能器件中起着至关重要的作用.在锂离子电池中,首圈放电过程中形成的固体电解质界面膜,通常被认为是一旦形成就稳定不分解的.而在过渡金属的催化下,这种电解质分解衍生的聚合物凝胶状膜(PGF)能可逆地形成和分解.这种过渡金属催化机制可以进行催化储锂,即形成的PGF具...     

等电位辉光放电电子温度的光谱测量与计算

用SII- IV 型全息凹面光栅单色仪对各种工艺参数条件下双层辉光等电位放电的发射光谱的相对强度进行了测量, 获得一系列光谱谱线。通过对玻尔兹曼方程式的计算, 得到了不同工艺条件下等离子放电时的电子温度。分析了工件电压、工作气压对电子温度的影响。结果表明: 在本工艺条件下, 电子温度随着工件电压的升高, 先减小后增大, 然后又减小, 并随着工作气压的增大而单调增大。工作气压的变化较工件电压的变化对电子温度的影响大。     

PERTURBATION FINITE ELEMENT METHOD FOR SOLVING GEOMETRICALLY NONLINEAR PROBLEMS OF AXISYMMETRICAL SHELL

In analysing the geometrically nonlinear problem of an axisymmetrical thin-walled shell, the paper combines the perturbation method with the finite element method by introducing the former into the variational equation to obtain a series of linear equations of different orders and then solving the equations with the latter. It is well-known that the finite element method can be used to deal with difficult problems as in the case of structures with complicated shapes or boundary conditions, and the perturbation method can change the nonlinear problems into linear ones. Evidently the combination of the two methods will give an efficient solution to many difficult nonlinear problems and clear away some obstacles resulted from using any of the two methods solely. The paper derives all the formulas concerning an axisym-metric shell of large deformation by means of the perturbation finite element method and gives two numerical examples,the results of which show good convergence characteristics.     

MicroRNAs电化学生物传感器在乳腺癌检测中的研究进展

MicroRNAs是一类内源性非编码小RNA分子,可调控靶基因的表达。特异性microRNAs的失调在诸如癌症、心血管疾病、免疫疾病、神经退行性疾病和皮肤疾病等的发展过程中起着关键作用,常作为疾病早期诊断和预后的生物标志物。电化学生物传感器由于其灵敏、快速、成本低等优势,已经成为传统microRNAs检测方法的一种很有前途的替代方法。本文综述了基于microRNA电化学生物传感器检测乳腺癌的研究进展,并对其所构建的电化学生物传感器的检测方法进行了分析探讨。     

Syntheses and Structures of Two Metalorganic Frameworks Constructed from Zn/Ni and 3-Formyl-4-(pyridin-4-yl) Benzoic Acid Ligand

Two metal-organic frameworks[(Zn_(0.5)L)·(H_2O)]_n(1)and[(Ni_(0.5)L)·(H_2O)]_n(2)constructed by the 3-formyl-4-(pyridin-4-yl)benzoic acid ligand(HL)were synthesized and characterized by single-crystal X-ray diffraction.1 crystallizes in orthorhombic space group Pnna with a=16.6152(8),b=12.6825(6),c=15.3908(8)?,V=3243.2(3)?~3,Z=4,M_r=511.12,D_c=1.047 g/cm~3,F(000)=1048,μ=1.144 mm~(-1),GOOF=1.061,the final R=0.0471 and w R=0.1262for 12168 observed reflections with I2σ(I).2 is isostructural to 1,which also crystallizes in orthorhombic space group Pnna with a=16.6152(8),b=12.6825(6),c=15.3908(8)?,V=3243.2(3)?~3,Z=4,M_r=511.12,D_c=1.047 g/cm~3,F(000)=1048,μ=1.144 mm~(-1),GOOF=1.061,the final R=0.0471 and w R=0.1262 for 12168 observed reflections with I2σ(I).Additionally,thermogravimetric analysis,FT-IR spectroscopy and powder X-ray diffraction were discussed.     

基于区间数的空气质量模糊综合评价模型

针对空气质量评价的不确定性,引入区间数概念进行2016年辽宁省各城市的空气质量综合评价和分析.参照国家大气质量标准,选用SO2、NO2、CO、PM2.5、PM10五种大气主要污染物作为评价因子,利用区间数计算污染因子的隶属度进行分析.考虑到城市差异,采用区间梯形隶属度函数,同时考虑区间数排序函数及可信度对区间数排序进行修正,避免了单因素得分区间数的发散,并综合确定评价等级.实例分析验证了该评价方法的可行性,依据收集的数据和此方法的结论得出空气质量的好坏与污染源分布、污染物扩散条件以及季节等因素有关.     

橡胶补强填料的研究进展

随着汽车行业的发展,在"安全、环保和节能"方面,对轮胎的性能提出了更高的要求,因此对轮胎原料—橡胶的补强研究越来越多。本文详细介绍了补强填料补强橡胶的机理、补强填料的分类及改性途径,概述了传统补强填料炭黑、白炭黑及炭黑/白炭黑双向填料的性能和研究现状,综述了新型补强填料硅酸盐类、碳酸盐类及其它常用新型种类和性能,指出新型填料拓展了橡胶补强技术和功能橡胶材料领域的研究思路,应加强橡胶补强填料的开发、补强机理探讨和拓展补强复合材料的表征和检测手段,以满足橡胶行业发展的需求。