Low-Temperature Magnetic Properties of Co Antidot Array

Cobalt antidot arrays with different thicknesses are fabricated by rf magnetron sputtering onto porous alumina substrates. Scanning electron microscopy and grazing incidence x-ray diffraction are employed to characterize the morphology and crystal structure of the antidot array, respectively. The temperature dependence of magnetic properties shows that in the temperature range 5K--300K, coercivity and squareness increase firstly, reach their maximum values, then decrease. The anomalous temperature dependences of coercivity and squareness are discussed by considering the pinning effect of the antidot and the magnetocrystalline anisotropy.     

Analytic Solution of Charge Density of Single Wall Carbon Nanotube under Conditions of Field Electron Emission

We derive the analytic solution of induced electrostatic potential along single wall carbon nanotubes. Under the hypothesis of constant density of states in the charge-neutral level, we are able to obtain the linear density of excess charge in an external field parallel to the tube axis.     

轻型汽车后桥半轴断裂件的组织及断口特征

采用光学显微镜和扫描电子显微镜等手段，对某轻型汽车40Cr后桥半轴断裂件的组织及断口特征进行了分析结果表明：半轴在调质处理时的淬火温度不够高，使其表层和心部组织中存在较多的铁素体相，造成了工件最终的硬度和疲劳强度不足，导致半轴在使用中发生扭转疲劳断裂．     

功能性丙烯酸/MBAM体系共聚产物的研制

以丙烯酸和MBAM为主要原料，经聚合，合成了一种高性能的具有良好保水性能的聚合产物，其保水量达到750～1000倍．50℃以下有良好的保水性能，28℃以下有极好的保水性能，并研究了工艺条件对该产品性能的影响因素．     

Synthesis and characterization of white‐light‐emitting polyfluorenes containing orange phosphorescent moieties in the side chain

Two orange phosphorescent iridium complex monomers, 9‐hexyl‐9‐(iridium (III)bis(2‐(4′‐fluorophenyl)‐4‐phenylquinoline‐N,C^2′)(tetradecanedionate‐11,13))‐2,7‐dibromofluorene (Br‐PIr) and 9‐hexyl‐9‐(iridium(III)bis(2‐(4′‐fluorophenyl)‐4‐methylquinoline‐N,C^2′)(tetradecanedionate‐11,13))‐2,7‐dibromofluorene (Br‐MIr), were successfully synthesized. The Suzuki polycondensation of 2,7‐bis(trimethylene boronate)‐9,9‐dioctylfluorene with 2,7‐dibromo‐9,9‐dioctylfluorene and Br‐PIr or Br‐MIr afforded two series of copolymers, PIrPFs and MIrPFs, in good yields, in which the concentrations of the phosphorescent moieties were kept small (0.5–3 mol % feed ratio) to realize incomplete energy transfer. The photoluminescence (PL) of the copolymers showed blue‐ and orange‐emission peaks. A white‐light‐emitting diode with a configuration of indium tin oxide/poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate)/PIr05PF (0.5 mol % feed ratio of Br‐PIr)/Ca/Al exhibited a luminous efficiency of 4.49 cd/A and a power efficiency of 2.35 lm/W at 6.0 V with Commission Internationale de L'Eclairage (CIE) coordinates of (0.46, 0.33). The CIE coordinates were improved to (0.34, 0.33) when copolymer MIr10PF (1.0 mol % feed ratio of Br‐MIr) was employed as the white‐emissive layer. The strong orange emission in the electroluminescence spectra in comparison with PL for these kinds of polymers was attributed to the additional contribution of charge trapping in the phosphorescent dopants. © 2007 Wiley Periodicals, Inc. JPolym Sci Part A: Polym Chem 45: 1746–1757, 2007     

真值维护系统的语义研究

本文研究了带有CP(Conditional Proof)验证式 TMS(Truth Maintenance System)理论的形式语义,证明了TMS理论J转换为新理论J*后,原指称的有效性;讨论了U. Junker和Kurt Konolige所定义的不带CP验证式 TMS理论的扩充在我们的语义模型中的有效性。此外,本文还讨论了CP验证式的一些性质,结论是:CP验证式和非单调可证明性、逻辑真有着密切的关系。     

鲁棒稳定性分析的值映射与参数化方法

本文运用值映射与参数化的方法研究了鲁棒D稳定性问题。文中给出了主要结果——参数空间鲁棒分析的边界定理,作为该结果的应用,一些现代鲁棒分析的知名结果,例如多项式族的稜边定理,Kharitonov定理和菱形定理都被简洁地证明出来;给出了一种判定双参数多项式族D稳定的新方法。用该方法可以方便地确定H稳定多项式按一定摄动模式(区间方式和菱形方形)的最大摄动界。     

万兆瓦可调谐窄线宽新型钕玻璃激光装置

本文报道了万兆瓦可调谐窄线宽新型钕玻璃激光装置的特色、所涉及的若干物理问题、装置的总体光路排布和关键技术,以及装置的总体输出性能。     

一种区间数的因子分析技术及其在证券市场中的应用

传统的因子分析技术能够有效地对高维变量空间进行降维处理,但它对于样本空间却缺乏行之有效的降维效果.为了解决这一问题,一种针对大量样本数据、新的因子分析技术———区间数因子分析技术(intervaldatafactoranalysis,IFA)被提出并得到了迅速的发展。IFA方法对传统的数据概念做了本质性的扩张,运用'数据打包'的理念,对海量原始数据在不破坏其原有内在逻辑关系的前提下,可以进行变量和样本点维度的双重降维。本文详细阐述了区间数因子分析技术的原理,并以中国股票市场为案例研究背景,结果表明IFA分析技术对大规模多维数据系统做综合简化是十分有效的。