超晶格量子阱长波红外焦平面阵列技术的进展

随着分子束外延(MBE)和有机金属化学汽相淀积(MOCVD)技术的发展,出现了新型的半导体超晶格量子阱长波红外探测器。本文分别评述 AlGaAs/GaAs,InGaAs,InAsSbⅢ-Ⅴ族化合物新型半导体超晶格量子阱器件目前的研究进展状况,着重于器件的工作机理、结构形式、制作工艺以及目前达到的主要性能参数水平,特别是在长波红外响应波长、暗电流和探测率方面的进展,在长波红外焦平面阵列方面的应用状况和发展前景。     

Dickson’s Lemma,Higman’s Theorem and Beyond: A survey of some basic results in order theory

We provide proofs for the fact that certain orders have no infinite descending chains and no infinite antichains.     

Temperature dependent growth of InGaN/GaN single quantum well

InGaN/GaN single quantum well (SQW) structures under various InGaN growth temperatures have been grown by metal organic chemical vapor deposition (MOCVD), the surface morphologies and optical properties are investigated. The radius of the typical V-pits on the SQW surface is affected by the InGaN well-temperature, and the surface roughness decreased as the well-temperature reduced. Room-temperature photoluminescence (PL) and cathode luminescence (CL) shows the quantum well and quantum dot (QD)-like localized state light emission of the SQWs grown at 700 and 690 °C, respectively, whereas the samples grown at 670 and 650 °C present hybrid emission peaks. Excitation power dependent PL spectra indicates the QD-like localized state emission dominates at low excitation power and the quantum well emission starts to take over at high excitation power.     

Scaling, multifractality, and long-range correlations in well log data of large-scale porous media

Three distinct methods, namely, the spectral density, the multifractal random walk approach, and the multifractal detrended fluctuation analysis are utilized to study the properties of four distinct types of well logs from three oil and gas fields, namely, the natural gamma ray emission, neutron porosity, bulk density, and the sonic transient time logs. Such well logs have never been analyzed by the methods that we utilize in the present study. The results indicate that the well logs exhibit multifractal characteristics, and the estimated Hurst exponents by the three methods are close to each other. Using multifractal detrended fluctuation analysis and the shuffled and surrogated data, we find that the source of multifractality is due to both broad probability density functions of the data and long-range correlations in them. The correlations are persistent and are characterized by a Hurst exponent H>0.5. Despite very significant differences in the geology of the three reservoirs-ranging from shaly sands to fractured carbonate reservoirs-there is a rough universality in the log data in that, the Hurst exponents for all the logs vary in a very narrow range.     

深井摄像测井系统关键技术研究

介绍了深井摄像测井系统的总体结构和工作过程,研究了系统的耐高温、高压,密封防护和视频信号无中继远距离传输等关键技术.现场试验表明该系统总体性能指标达到了设计要求.     

Well Hydraulics with the Weber–Goldstein Transforms

Two new integral transforms, ideally suited for solving boundary value problems in well hydraulics, are derived from one of the Goldstein identities which generalizes a corresponding Weber identity. The two transforms are, therefore, named the Weber–Goldstein transforms. Their properties are presented. For the first, second, and third type boundary conditions, the new transforms remove the radial portion of a Laplacian in the cylindrical coordinates. They are used to straightforwardly rederive known solutions to the problems of a fully penetrating flowing well and a fully penetrating pumped well. A novel solution for a fully penetrating flowing well with infinitesimal skin situated in a leaky aquifer is also found by means of one of the new transforms. This solution is validated by comparison to a numerical solution obtained via the finite-difference method and to a quasi-analytic solution obtained by numerical inversion of the corresponding solution in the Laplace domain. Based on the new solution, a flowing well test is proposed for estimating the hydraulic conductivity and specific storativity of the aquifer and the skin factor of the well. The test can also be used in a constant-head injection mode. A type-curve estimation procedure is developed and illustrated with an example. The effectiveness of the test in estimating the well skin factor and aquifer parameters depends on the availability of data on the sufficiently early well response.     

量子阱激光器超晶格缓冲层的研究

在量子阱半导体激光器结构中采用优化超晶格缓冲层来掩埋衬底缺陷，获得了性能优良的激光器。对超晶格缓冲层所具有的“量子阱陷阱效应”进行了理论分析。     

广义共同逼近问题的适定性

设C是实Banach空间X中有界闭凸子集且0是C的内点，G是X中非空闭的有界相对弱紧子集.记K(X)为X的非空紧凸子集全体并赋Hausdorff距离，KG(X)为集合｛A∈K(X)；A∩G=｝的闭包.称广义共同逼近问题minC(A,G)是适定的是指它有唯一解(x0,z0)，且它的每个极小化序列均强收敛到(x0,z0).在C是严格凸和Kadec的假定下，证明了｛A∈K(X)；minC(A，G)是适定的｝含有KG(X)中稠Gδ子集，这本质地推广和延拓了包括De Blasi,Myjak and Papini［1］、Li［2］和De Blasi and Myjak［3］等人在内的近期相应结果.     

量子阱激光器的阈值电流和外量子效率

地于半导体分别限制单量子阱激光器，为了降低阈值电流，提高外量子效率，分析和讨论了影响阈值电流和外量子效率的各种因素，并做了一定的数值计算，给出了量佳结构参数。