Best Proximity Point Theorems for p-Proximalα-η-β-Quasi Contractions in Metric Spaces with w0-Distance

In this paper,we propose a new class of non-self mappings called p-proximalα-η-β-quasi contraction,and introduce the concepts ofα-proximal admissible mapping with respect toηand(α,d)regular mapping with respect toη.Based on these new notions,we study the existence and uniqueness of best proximity point for this kind of new contractions in metric spaces with w;-distance and obtain a new theorem,which generalize and complement the results in[Ayari,M.I.et al.Fixed Point Theory Appl.,2017,2017:16]and[Ayari,M.I.et al.Fixed Point Theory Appl.,2019,2019:7].We give an example to show the validity of our main result.Moreover,we obtain several consequences concerning about best proximity point and common fixed point results for two mappings,and we present an application of a corollary to discuss the solutions to a class of systems of Volterra type integral equations.     

基于冲击光谱测量的氧化铝晶体高压相变诊断技术

氧化铝晶体是一种优良的光学透明窗口材料,更是地球内部的重要组成物质.利用气炮加载结合冲击光谱测量,不仅能够获得其发光特征,并且根据光谱分布特征得到高压结构相变信息.在自主搭建的冲击光谱动态测试平台上,结合多通道辐射高温计以及ICCD瞬态光谱测试技术在40~120 GPa的压力区间,研究了c切向氧化铝晶体的辐射发光效应.在可见光波段400~700 nm区间获得了氧化铝晶体的发光光谱和辐射温度结果,证实了光谱的结构特征和表观温度值与该压力下氧化铝的结构相变存在明显的关联性.     

减压扩散高阻密栅技术应用研究

本文对减压扩散机理及高阻密栅技术作了详细的分析,并就设备及工艺方面的关键技术进行了阐述,最后对减压扩散高方阻工艺及密栅匹配技术电池效率进行了对比分析,有以下结论:(1)减压扩散在工艺优化后,方阻均匀性得到大幅改善,达到3;以内.(2)减压扩散电池效率完全可达到常规产线的水平,且在高阻密栅方面更有优势,可有效提升太阳电池效率.     

Cu2O/TiO2-Bi2WO6三元复合催化剂的制备及光催化性能研究

采用水热法制备花状Bi2 WO6,并利用超声分散法制备了Cu2 O/TiO2-Bi2 WO6复合光催化剂,通过FESEM、XRD、XPS、FI-IR、UV-vis DRS和PL对光催化剂进行了分析和表征.表征结果证明:花状Bi2 WO6表面负载着碎片状的TiO2和立方体Cu2 O形成Cu2 O/TiO2-Bi2 WO6复合光催化剂;以短链脂肪酸(SCFAs)为牺牲剂,考察复合光催化剂的光催化产生氢气和烷烃的性能.实验结果表明:Cu2 O/TiO2-Bi2 WO6复合光催化剂以乙酸为牺牲剂,主要产氢气和甲烷,降解率高达91.82;;以丙酸为牺牲剂,产物主要是乙烷和丁烷,降解率高达90.70;;以丁酸为牺牲剂,除了氢气,甲烷,乙烷,丙烷,丁烷外,气体产物还含有一定量的戊烷,其降解率高达91.50;.结合反应液中间产物的成分进行检测,由此推断出光催化反应的可能机理.     

Theoretical study of (e,2e) triple differential cross sections of pyrimidine and tetrahydrofurfuryl alcohol molecules using multi-center distorted-wave method

We report theoretical studies of electron impact triple differential cross sections of two bio-molecules,pyrimidine and tetrahydrofurfuryl alcohol,in the coplanar asymmetric kinematic conditions with the impact energy of 250 eV and ejected electron energy of 20 eV at three scattering angles of-5°,-10°,and-15°.Present multi-center distorted-wave method well describes the experimental data,which was obtained by performing(e,2e)experiment.The calculations show that the secondary electron produced by the primary impact electron is strongly influenced by the molecular ionic multi-center potential,which must be considered when the low energy electron interacts with DNA analogues.     

Comparative study on transport properties of N-, P-, and As-doped SiC nanowires: Calculated based on first principles

According to the one-dimensional quantum state distribution, carrier scattering, and fixed range hopping model, the structural stability and electron transport properties of N-, P-, and As-doped SiC nanowires(N-SiCNWs, P-SiCNWs, and As-SiCNWs) are simulated by using the first principles calculations. The results show that the lattice structure of NSiCNWs is the most stable in the lattice structures of the above three kinds of doped SiCNWs. At room temperature,for unpassivated SiCNWs, the doping effect of P and As are better than that of N. After passivation, the conductivities of all doped SiCNWs increase by approximately two orders of magnitude. The N-SiCNW has the lowest conductivity. In addition, the N-, P-, As-doped SiCNWs before and after passivation have the same conductivity–temperature characteristics,that is, above room temperature, the conductivity values of the doped SiCNWs all increase with temperature increasing.These results contribute to the electronic application of nanodevices.     

水下多级微结构液气界面的稳定性和可恢复性研究

微结构表面浸没水下所形成的液气界面对减阻等应用具有重要意义.液气界面的稳定存在是结构功能表面发挥作用的前提.因此,如何增强液气界面的稳定性以抵抗浸润转变过程,以及在液气界面失稳之后,如何实现去浸润过程以提高液气界面的可恢复性能,均具有重要的科学研究意义和实际应用价值,也是国内外研究关注的热点问题.本文针对具有多级微结构的固体表面,研究其在浸没水下后形成的液气界面的稳定性和可恢复性.通过激光扫描共聚焦显微镜对不同压强下液气界面的失稳过程和降压后的恢复过程进行原位观察,实验结果和基于最小自由能原理的理论分析相吻合.本文揭示了多级微结构抵抗浸润转变以及提高液气界面可恢复性能的机理:侧壁上的次级结构(纳米颗粒、多层翅片)通过增加液气界面在壁面的表观前进接触角增强了液气界面的稳定性;底面的次级结构(纳米颗粒和封闭式次级结构)可以维持纳米尺寸气核的存在,有利于水中溶解气体向微结构内扩散,最终使液气界面恢复.本文的研究为通过设计多级微结构表面来获得具有较强稳定性和可恢复性的液气界面提供了思路.     

线性方程组求解与向量组规范化的初等变换方法

本通过对线性方程组的系数矩阵的行与列的初等变换给出了求解线性方程组的方法，并通过对矩阵的初等变换给出了向量组正化的方法。     

二阶椭圆问题的混合有限元估计

关于二阶椭圆问题，[1]中给出了一种混合有限格式，但所用的自由度太多，给实     

固体力学有限元体系的结构拓扑变化理论

本文是文[1]的继续.文[1]提出了杆件系统的结构拓扑变化理论和拓扑变化法本文将这一理论和方法推进到连续体有限元体系;且在此基础上揭示出有限元体系的一个新性质,称为基本位移之梯度的正交性定理,从而给出一套设计敏度的显式表达式,可直接用于计算.