新疆天山北坡典型研究区融雪期地物光谱特征分析

地物的波谱特性乃是整个遥感技术的物理基础,更是遥感技术应用尤其是定量遥感的基石。由于融雪期静态地物与冰-雪-水等动态地物交互存在,地物光谱特征更为复杂。选取了新疆天山北坡乌鲁木齐河流域以及军塘湖流域作为典型研究区,采用美国CID公司生产的CI700便携式野外光谱仪,通过2006年到2009年融雪期大量的野外调查和实地测量,获取了新疆天山北坡典型研究区融雪期典型地物包括各种积雪、冰、水以及土壤的光谱曲线及其变化规律,并对其进行了光谱特征分析。结果表明,融雪期虽然地物类型较为单一,但是因为积雪-冰-水-土壤复杂系统的交互式影响,地物的光谱特性及其变化均较为复杂,给融雪期地表参数的定量遥感研究带来了较大的挑战。对于融雪期复杂地物光谱的系列观测及特征分析无论是对于地物光谱特征基础研究还是定量遥感应用研究均具有重要意义。     

Characteristics of pentacene organic thin film transistor with top gate and bottom contact

High performance pentacene organic thin film transistors (OTFT) were designed and fabricated using SiO₂ deposited by electron beam evaporation as gate dielectric material. Pentacene thin films were prepared on glass substrate with S--D electrode pattern made from ITO by means of thermal evaporation through self-organized process. The threshold voltage V_TH was --2.75± 0.1V in 0---50V range, and that subthreshold slopes were 0.42± 0.05V/dec. The field-effect mobility (μ_EF) of OTFT device increased with the increase of V_DS, but the μ_EF of OTFT device increased and then decreased with increased V_GS when V_DS was kept constant. When V_DS was --50V, on/off current ratio was 0.48× 10⁵ and subthreshold slope was 0.44V/dec. The μ_EF was 1.10cm²/(V.s), threshold voltage was --2.71V for the OTFT device.     

Short Tm3+-doped fiber lasers with watt-level output near 2 μm

High-power operation of diode-pumped fiber lasers at wavelength near 2μm are demonstrated with short length of heavily Tm3 -doped silica glass fibers. With 7-cm long fiber, a laser at near 2 μm is obtained with the threshold of 135 mW, maximum output power of 1.09 W, and slope efficiency of 9.6% with respect to the launched power from a laser diode at 790 nm. The output stability of this fiber laser is within 5%.The dependence of the performance of fiber lasers on the operation temperature and cavity configuration parameters is also investigated.     

Slope enclosures for functions given by two or more branches

In this paper, we consider the automatic computation of slope enclosures for continuous real functions given by two or more branches, such as piecewise defined nonsmooth functions. We show that a commonly used formula found in the literature does not always provide a slope enclosure for such functions. Furthermore, we prove a similar formula that always holds. AMS subject classification (2000)  65G20     

Anomalous Scaling of Surface Growth Equations with Spatially and Temporally Correlated Noise

Based on the scaling idea of local slopes by Lopez et al. [Phys. Rev. Lett. 94 （2005） 166103], we investigate anomalous dynamic scaling of （d ＋ 1）-dimensional surface growth equations with spatially and temporally correlated noise. The growth equations studied include the Kardar-Parisi-Zhang （KPZ）, Sun-Guo-Grant （SGG）, and Lai-Das Sarma-Villain （LDV） equations. The anomalous scaling exponents in both the weak- and strong-coupling regions are obtained, respectively.     

Slope parameter and scaling of differential cross-section of Λ-p scattering

The claim of Mohapatra and Maharana thattb(s) is a better scaling variable thant(lns)² is put to test in the case of Λ-p scattering, after parametrizingb(s) asC ₁ +C ₂(lns)α. It was observed that in this case the data also prefer anα value which is close to those obtained by Mohapatra and Maharana for other scattering processes.     

Composition assessment of ferric oxide by accurate peak fitting of the Fe 2p photoemission spectrum

A quantitative study of the surface composition of ferric oxide employing photoemission spectra is presented. It was possible to accurately reproduce the expected composition (Fe_2.00±0.05O₃) by modeling the background as a combination of Shirley‐type (Shirley–Vegh–Salvi–Castle) and slope backgrounds through the active approach. The line‐shape employed to fit apparent peak asymmetries was the double‐Lorentzian. It was possible to resolve a previously unreported satellite located at ~729 eV. Copyright © 2016 John Wiley & Sons, Ltd.     

基于相平均方法的折射绕射联合波浪模型

近岸带波浪运动的研究具有很重要的工程意义，近年来已获得了较丰硕的研 究成果并发展了许多波浪模型，而基于不同理论的波浪模型往往具有特定的适用性. 在海岸 工程中应用比较广泛的一类波浪模型以波能(波作用量)守恒为基本依据，如SWAN模型. 该 类模型在实际工程中已经得到了大量的应用，但该类模型未计及波浪绕射效应，成为其突出 的缺陷之一. 如何对模型做适当的改进，使之适用于波浪绕射的模拟，从而在原有基础上拓 广模型的应用范围是一项具有实际意义的研究工作. 该文采用波能(波作用量)守恒方程描 述近岸带波浪运动，通过引入绕射因子，得到折射、绕射联合波浪模型，从而拓广了模型的 应用范围. 通过实际算例验证，表明所建立的模型计及了波浪折射、绕射作用，对相平 均波浪模型在波浪绕射效应模拟方面的改进具有一定的意义.     

Adaptive hierarchic transformations for dynamically p-enriched slope-limiting over discontinuous Galerkin systems of generalized equations

We study a family of generalized slope limiters in two dimensions for Runge–Kutta discontinuous Galerkin (RKDG) solutions of advection-diffusion systems. We analyze the numerical behavior of these limiters applied to a pair of model problems, comparing the error of the approximate solutions, and discuss each limiter’s advantages and disadvantages. We then introduce a series of coupled p-enrichment schemes that may be used as standalone dynamic p-enrichment strategies, or may be augmented via any in the family of variable-in-p slope limiters presented.     

基于布拉格光栅的边坡监测实验研究

提出了一种基于分布式光纤光栅的边坡监测与报警系统.根据强度折减法,利用ANSYS软件分析出边坡的软弱面及滑体所在的具体位置,从而在该处安装经过特殊封装的拉线式光纤光栅位移传感器.滑体的位移通过拉线转换为作用在光栅上的应力,而光纤光栅反射波长与应变具有良好的线性关系,因此通过检测光栅反射光的中心波长的偏移量,就可以解调出...