Characterization of ZnO: Al films deposited by r.f. magnetron-sputtering at low temperature

Transparent conducting ZnO: Al thin films with good adhesion and low resistivity have been prepared on organic substrates and Corning 7059 glass substrates by r.f. magnetron-sputtering technique at low substrate temperature (25–210°C). Structural and photoelectric properties of the deposited films are investigated. The deposited films are polycrystalline with hexagonal structure and a preferred orientation with the c-axis perpendicular to the substrate. Only the (002) peak is observed. High quality films with resistivity as low as 1.0 x 10^-3Ω·cm and 8.4 x 10^-4Ω·cm, the average transmittance over 74% and 85% in the wavelength range of the visible spectrum have been obtained on different substrates.     

Synthesis and characterization of C3N4 hard films

C3N4 films have been synthesized on both Si and Pt substrates by microwave plasma chemical vapor deposition (MPCVD) method. X-ray spectra were calculated for single phase α-C3N4 and β-C3N4 respectively. The experimental X-ray spectra of films deposited on both Si and Pt substrates showed all the strong peaks of α-C3N4 and β-C3N4, so the films are mixtures of α-C3N4 and β-C3N4. The N/C atomic ratio is in the range of 1.0-2.0. X-ray photoelectron spectroscopy (XPS) analysis indicated that the binding energy of C 1s and N 1s are 286.2 eV and 399.5 eV respectively, corresponding to polarized C-N bond. Fourier transform infrared absorption (FT-IR) and Raman spectra support the existence of C-N covalent bond in the films. Nano-indentation hardness tests showed that the bulk modulus of a film deposited on Pt is up to 349 GPa.     

Epitaxial growth and electrical transport properties of La0.5Sr0.5Co03 thin films prepared by pulsed laser deposition

Epitaxial growth of the La_0.5Sr_{0.5 3}(LO) thin films has been realized on Lin3, SrTiC₃ and MgO substrates by pulsed laser deposition. The epitaxial growth behavior and the electrical transport properties of these films were studied systematically. The temperature dependencies of the resistivity of the film have been determined. Studies indicate that close dependencies exist between the crystal structures and the electrical transport properties of the epitaxial LSCO films, and that the epitaxial thin films are of low resistivity and metallic conductive features. The epitaxial films deposited on the LaA10₃ substrates at about 700 °C possess the optimal properties compared with the others. Discussions of the dependencies and the mechanisms of the epitaxial structures on the electrical transport properties of the LSCO films have been made. Project supported by the National Natural Science Foundation of China (Grant No. 19574003 and No. 19674001).     

关于非线性椭圆边值问题解的存在性的注

利用非线性增生映射值域的扰动理论,本文研究了与P拉普拉斯算子△p相关的非线性椭圆边值问题@在Ls(Ω)空间中解的存在性,其中2>sp>2nn+1且n1.@-Δpu+|u(x)|p-2u(x)+g(x,u(x))=fa.e.x∈Ω-〈υ,|u|p-2u〉=0a.e.x∈Γ其中f∈Ls(Ω)给定,ΩRn,n1,Δpu=div(|u|p-2u)为P拉普拉斯算子,υ为Γ的外法向导数,g∶Ω×R→R满足Caratheodory条件.本文所讨论的方程及所用的方法是对以往一些工作的补充和延续.     

对非线性椭圆边值问题解的存在性的研究

利用非线性增生映射值域的扰动定理 ,研究了非线性椭圆边值问题 ( @)在 L2 (Ω )中解的存在性 .( @) -△pu +g( x,u) =f a.e.在Ω中-〈v,| u|p- 2 u〉∈βx( u( x) ) a.e.在Γ上其中 f∈ L2 (Ω )给定 ,Ω RN,N 1 ,△ pu=div( | u|p- 2 u)为 P拉普拉斯算子 ,1 2 NN +1 ,v为 Γ的外法向导数 ,g:Ω× R→ R满足 Caratheodory条件 ,对 x∈ Γ,βx是正常、凸、下半连续函数 φx=φ( x,· )的次微分 ,其中 φ:Γ×R→ R.     

Relative asymptotics for orthogonal matrix polynomials with respect to a perturbed matrix measure on the unit circle

Given a positive definite matrix measure Ω supported on the unit circle T, then main purpose of this paper is to study the asymptotic behavior of Ln(Ω)Ln(Ω)-1 and Φn(z;Ω)Φn(z;Ω)-1 where Ω(z) = Ω(z) + zδ(z - w); |w| ＞ 1,M is a positive definite matrix and δ is the Dirac matrix measure. Here, Ln ( @ ) means the leading coefficient of the orthonormal matrix polynomials Φn(z; @ ).Finally, we deduce the asymptotic behavior of Φn (w;Ω)Φn (w;Ω) * in the case when M=I.     

一类非线性椭圆边值问题解的存在性

目前 ,对 s——拉普拉斯算子△s的研究是较为活跃的数学课题 .原因在于算子 -△s与许多物理现象有关 .比如 :反射扩散问题 ,石油提取问题等等 .基于此因 ,在文 [3]的基础上 ,我们将继续研究以下非线性边值问题在 Ls(Ω) ,( 1 2 nn+1 )中解的存在条件 .-△su +g( x,u) =f几乎处处在Ω中-〈 ,| u|s- 2 u〉 =0几乎处处在Γ上其中 f∈Ls( Ω)给定 ,Ω Rn( n 1 ) ,△su=div( | u|s- 2 u) ,g∶Ω× R→ R满足 Caratheodory条件 .本文把文 [3]关于非线性边值问题 @在 Lp( Ω) ( 2 p<+∞ )空间中解的存在性的研究推广到 Ls( Ω) ( 1 2 nn+1 )空间中 .     

一类带扰动的非线性椭圆型方程组无穷多弱解的存在性

本文在一定条件讨论了如下一类带扰动项,且被两个Laplacian算子控制的非线性椭圆方程Dirichlet问题无穷多弱解的存在性.（-△u=∣u∣α-1∣υ∣β＋1u＋f,x∈Ω,-△υ=∣u∣α＋1∣υ∣β-1υ＋g,x∈Ω,u（x）＋ υ（x）=0,x∈（e）Ω,）其中-△u：=div（▽u）,（u,υ）∈E：=H10（Ω）× H10（Ω）,（f,g）属于E的对偶空间.     

Synthesis and characterization of C3N4 hard films

C₃N₄ films have been synthesized on both Si and Ft substrates by microwave plasma chemical vapor deposition (MPCVD) method. X-ray spectra were calculated for single phase α-C₃N₄ and β-C₃N₄ respectively. The experimental X-ray spectra of films deposited on both Si and Pt substrates showed all the strong peaks of α-C₃N₄ and β-C₃N₄ so the films are mixtures of α-C₃N₄ and β-C₃N₄. The N/C atomic ratio is in the range of 1.0–2.0. X-ray photoelectron spectroscopy (XPS) analysis indicated that the binding energy of Is and N ls are 286.2 eV and 399.5 eV respectively, corresponding to polarized C-N bond. Fourier transform infrared absorption (FT-IR) and Raman spectra support the existence of C-N covalent bond in the films. Nano-indentation hardness tests showed that the bulk modulus of a film deposited on Pt is up to 349 GPa     

Microscale mechanics for metal thin film delamination along ceramic substrates

The metal thin film delamination along metal/ceramic interface in the case of large scale yielding is studied by employing the strain gradient plasticity theory and the material microscale effects are considered. Two different fracture process models are used in this study to describe the nonlinear delamination phenomena for metal thin films. A set of experiments have been done on the mechanism of copper films delaminating from silica substrates, based on which the peak interface separation stress and the micro-length scale of material, as well as the dislocation-free zone size are predicted.     

带权的 p-Laplacian 非线性特征值问题解的存在性

文利用变分方法讨论了方程-△p^u=λ a(x)(u^{+})^q-1-μ a(x)(u^-)^q-1+f(x,u), u∈W₀^1,p(Ω), 当 p≠q时的可解性. 其中Ω是 R^N(N≥ 3)中的有界光滑区域,权重函数a(x)∈ L^r(Ω), (r≥Np/Np-Nq+pq)且a(x)>0, a.e.于Ω, f满足某些条件.     

渐近线性椭圆方程组的非负解

本文讨论了如下一类渐近线性椭圆方程组{-Δu-μΔv=g(x,v),-Δv-λΔu=f(x,u),x∈Ω,u=v=0,x∈(e)Ω在H10(Ω)×H10(Ω)中至少存在一个非负非平凡的解对(u,v),其中Ω是RN中的一个光滑有界区域,f(x,t)和g(x,t)是Ω×R上的连续函数并且在无穷远处渐近线性.     

High-T c superconducting thin film/GaAs MESFET hybrid microwave oscillator

A high-T _c superconducting (HTSC) thin film/GaAs MESFET hybrid microwave oscillator operated at 10.6 GHz has been designed, fabricated and characterized. Microstrip line structures were used throughout the circuit with superconducting thin film YBa₂Cu₃O_7-δ(YBCO) as the conductor material. The YBCO thin films were deposited on 15 mm×10 mm×0.5 mm LaAlO₃ substrates. The oscillator was common-source, series feedback type using a GaAs-MESFET (NE72084) as the active device and a superconducting microstrip resonator as the frequency stabilizing element. By improving the unloaded quality factorQ ₀ of the superconducting microstrip resonator and adjusting the coupling coefficient between the resonator and the gate of the MESFET, the phase noise of the oscillator was decreased. At 77 K, the phase noise of the oscillator at 10 kHz offset from carrier was −87 dBc/Hz. Project supported by the National Center for Research and Development on Superconductivity of China.     

带粗糙核的Marcinkiewicz积分算子在Herz空间的有界性

本文考虑如下的Macinkiewicz积分算子μΩ（f）（x）{∫0^∞｜FΩ ,t（x）｜^2t^-3dt}^1/2,其中FΩ ,t（x）=∫｜x-y｜≤tΩ （x-y）｜x-y｜^-n＋2f（y）dy在一定的条件下证明它是在Herz空间Kq^α,q上有界同时也是从Herz空间K1^α,p到弱Herz空间WK1^α,p上有界。     

A-调和方程弱解的新的加权积分不等式

研究形如div A(x,u(x))=0的A-调和方程,证明其弱解满足局部Arλ3(λ1,λ2,Ω)-权Caccioppoli型不等式,这可看作A-调和方程相应结果的推广.最后给出上述结果在拟正则映射中的应用.     

临界Hartree方程组基态解的存在性

本文考虑临界耦合的Hartree方程组{-△+λu=∫Ω|u(z)|^2*μ/|x-z|μdz|u|^2*μ-2u+βν,x∈Ω,-△+νu=∫Ω|ν(z)|^2*μ/|x-z|μdz|u|^2*μ-2u+βν,x∈Ω,其中Ω是RN中带有光滑边界的有界区域,N≥3,λ,v是常数,且满足λ,v>-λ1(Ω),λ1(Ω)是(-△,H01(Ω))的第一特征值,β> 0是耦合参数,临界指标2μ*=(2N-μ)/(N-2)来源于Hardy-LittlewoodSobolev不等式,利用变分的方法证明了临界Hartree方程组基态正解的存在性.     

一个山路引理的应用

本文主要考虑如下形式的Dirichlet问题-△u(x)=f(x,u),x∈Ω,∈H01(Ω),其中f(x,t)∈C(Ω×R),f(x,t)/t关于t单调不减,并且当t∈R时关于x∈Ω一致趋向于某个L∞函数q(x)(此时,称f(x,t)关于t在无穷远处是渐近线性的).显然,在该条件下常用的Ambrosetti-Rabinowitz型条件,即关于所有的|s|>M和x∈Ω,0<θF(x,s)2,M>0为常数, F(x,s)=∫0s f(x,t)dt. 众所周知,条件(AR)在山路引理的应用中起着非常重要的作用.本文通过应用一种改进了的山路引理在没有条件(AR)的情况下来证明上面Dirichlet问题(P)也有正解存在。此方法也适用于f(x,t)关于t在无穷远处是超线性,即q(x)≡+∞的情形.     

REGULARITY RESULTS FOR SOME QUASI-LINEAR ELLIPTIC SYSTEMS INVOLVING CRITICAL EXPONENTS

The authors show the regularity of weak solutions for some typical quasi-linear elliptic systems governed by two p-Laplacian operators. The weak solutions of the following problem with lack of compactness are proved to be regular when α(x) and α,β,p, q satisfy some conditions: where Ω(?) RN (N≥3) is a smooth bounded domain.     

SPECTRAL GAP SOLUTIONS OF THE DISSIPATIVE KIRCHHOFF EQUATION

§1. Introduction This paper is devoted to the question of the global solvability of the dissipative Kirch-ho? equation ?t u ? m 2 | x u|2dx x u δ?tu = 0 (x ∈?, t > 0), …     

集值映射的不动点指数与带间断非线性项的椭圆型方程的多重解

<正> 本文研究二阶半线性椭圆边值问题■的多重解(符号详见§3),其中φ(x,t)允许对t是不连续的.一些自由边界问题可以化归这类问题.为了统一处理φ(x,t)对t连续与不连续两种情形,我们采用集值映射的观点.为此推广了经典的算子与Hammerstein算子到集值映射,并发展了集值映射的Leray-Schauder度理论;与已有的集值映射理论不同,现在处理的是映射串(定