A Novel 0.72-6.2GHz Continuously-Tunable Delta Sigma Fractional-N Frequency Synthesizer

This paper presents a wideband Delta Sigma-based fractional-N synthesizer with three integrated quadrature VCOs for multiple-input multiple-output (MIMO) wireless communication applications. It continuously covers a wide range frequency from 0.72GHz to 6.2GHz that is suitable for multiple communication standards. The synthesizer is designed in 0.13-um RE CMOS process. The dual clock full differential multi-modulus divide (MMD) with low power consumption can operate over 9GHz under the worst condition. In the whole range frequency from 0.72GHz to 6.2GHz, the maximal tuning range of the QVCOs reaches 33.09% and their phase noise is -119d8/Hz similar to 124d8/Hz @1MHz. Its current is less than 12mA at a 1.2V voltage supply when it operates at the highest frequency of 6.2GHz.

Evaluating 0.53 eVGaInAsSbthermophotovoltaic diode based on an analytical absorption model

Radiant heat conversion performance dominated by the active layer of Ga0.84In0.16As0.14Sb0.86 diode has been systematically investigated based on an analytic absorption spectrum, which is suggested here by numerically fitting the limited experimental data. For the concerned diode configuration, our calculation demonstrates that the optimal base doping is 3-4 x 10(17) cm(-3), which is less sensitive to the variation of the external radiation spectrum. Given the scarcity of the alloy elements, an economical device configuration of the 0.2-0.6 mu m emitter and the 4-6 mu m base would be particularly acceptable because the corresponding conversion efficiency cannot exhibit discouraging degradation in comparison to the one for the optimal structure, the thickness of which may be up to 10 mu m. More importantly, the method we suggested here to calculate alloy absorption can be easily transferred to other composition, thus bringing great convenience for design or optimization of the optoelectronic device formed by these alloys.

支持WSRP 2.0规范的联邦门户的设计与实现

门户（Portal）是基于组件的web应用，它可以集成Internet环境下各种现有应用系统、数据资源和网络信息资源，并为用户形成个性化的访问页面，实现信息的集成和发布。Portlet是门户中的可重用组件，能够提供对web内容、应用程序和其他资源的访问。JSR168规范（Portlet 1.0）和JSR286规范（Portlet 2.0）提供了Portlet的标准。 随着门户的广泛使用，门户已经成为获取信息，巩固和整合IT基础设施的平台。于是来自于同一公司的、自主的、分散的多个部门都部署了自己的门户，但这些门户之间却无法进行内容共享，即Portlet在门户之间的集成。于是出现了联邦门户（Federated Portals），它是由多个分散的门户构成的网络，这些门户基于共同的标准协同工作。联邦门户实现了在异构门户之间共享远程内容，这些远程内容来自于名为生产者的门户，被收集、组合和运行在名为消费者的门户中。 联邦门户的基本特征是基于规范实现跨门户的系统联合。因此联邦门户的关键在于对门户间互操作标准的制定。这个标准就是OASIS推出的WSRP（Web Services for Remote Portlets）规范。WSRP规范提供了门户间互操作标准，成为联邦门户的基础技术。它有1.0和2.0两个版本，分别产生于2003年和2008年。 为了提高联邦门户应用的构建效率，增强异构门户互操作性的能力，完善联邦门户的用户友好性，需要为OncePortal提供支持WSRP 2.0规范的联邦门户。 本文从WSRP 2.0规范和联邦门户的需求出发，设计并实现了支持WSRP 2.0规范的联邦门户。首先根据WSRP 2.0规范对远程Portlet的语法模型、交互模型和生命周期模型三个方面进行特征分析；其次总结了联邦门户的核心功能、系统边界，并给出了联邦门户的设计；然后从Portlet URL的生成与改写、Portlet统一协作框架、远程Portlet资源服务、WSRP容器和代理容器以及Portlet缓存共5个方面介绍了联邦门户的关键技术；最后基于以上分析和设计，实现了联邦门户扩展应用，并将其应用在中科院软件所自主研发的门户产品OncePortal中。

气相贝克曼重排新型固体酸催化剂研究

己内酰胺是一种重要的有机化工原料。采用环己酮肟的气相Beckmann重排的方法制己内酰胺可以解决传统的液相工艺中存在的副产硫酸胺、腐蚀设备和污染环境等问题。本研究的目的是开发出适合环己酮肟的气相Beckmann重排的固体酸催化新工艺。 首先，本工作用同位素标记的方法研究了Beckmann重排在固体酸B2O3/γ-Al2O3和TS-1上的反应机理。同位素标记后的产品采用质谱测量。通过与H218O交换氧，发现环己酮肟与H218O的交换在B2O3/γ-Al2O3和TS-1只能进行到一定程度，这暗示固体酸上腈中间体的解离不如经典的机理完全。提出了解离度(α)的概念，其定义为解离了中间体腈与总中间体腈之比。通过拟合实验数据和同位素标记的产品的计算公式，获得了B2O3/γ-Al2O3和TS-1上α 值分别为0.199和0.806的结果。 其次，采用对氧化铝表面合适氟化的方法，对氟化的氧化铝的性能进行研究。发现氧化铝表面氟化可以改善Beckmann重排的性能。氧化铝表面氟化可以消除其表面碱性位，说明了催化剂表面碱性位不利于Beckmann重排。而完全氟化的氧化铝的选择性不如某些固体酸如负载B2O3和Silicalite-1，暗示着表面酸强度也影响催化剂的选择性。同时，我们对适合气相Beckmann重排的催化剂进行了简单的筛选。发现一种稀土焦磷酸盐有可能是适合此反应的催化剂。 再次，研究了稀土焦磷酸盐催化剂上气相Beckmann重排。通过对一些稀土磷酸进行XRD,FT-IR,NH3-TPD和水接触角等表征，发现这类催化剂上表面的弱酸位以及合适的表面疏水是它们具有较好性能的原因。 再次，对焦磷酸铈催化剂的合成以及反应氛围进行了优化。发现优化的反应氛围为催化剂在pH在3~4时沉淀，在500~550度焙烧，在~350度反应，载气~80ml/min，空速在0.43h-1时反应，能保持转化率在98％以上，选择性在70％以上，8小时不失活。 最后，采用P123作为模板剂合成了一种新型的中孔稀土磷酸盐，这种稀土磷酸盐具有无序的虫洞形结构。应用这种新型的中孔稀土磷酸盐于酚类甲醇氧烷基化获得了较好的结果。与不加表面活性剂的材料相比，这种中孔稀土磷酸盐在低温下具有更大的活性并且其选择性不受损失。认为这种中孔的形态对催化性能具有好的影响。

FIELD-EFFECT ON THERMAL EMISSION FROM THE 0.40 EV ELECTRON LEVEL IN INGAP

Results are reported of electric-field dependence on thermal emission of electrons from the 0.40 eV level at various temperatures in InGaP by means of deep-level transient spectroscopy. The data are analyzed according to the Poole-Frankel emission from the potentials which are assumed to be Coulombic, square well, and Gaussian, respectively. The emission mte from this level is strongly field dependent. It is found that the Gaussian potential model is more reasonable to describe the phosphorus-vacancy-induced potential in InGaP than the Coulombic and square-well ones.

MOCVD生长Al_(0.48)Gao_(0.52)N/Al_(0.54)Ga_(0.36)N多量子阱的结构和光学特性

采用金属有机物化学气相淀积(MOCVD)技术,在蓝宝石衬底上生长了Al_(0.48)Gao_(0.52)N/Al_(0.54)Ga_(0.36)N多量子阱(MQWs)结构.通过双晶X射线衍射(DCXRD)、原子力显微镜(AFM)和阴极荧光(CL)等测试技术,分别对样品的结构和光学特性进行了表征.在DCXRD图谱中,可以观察到明显的MQWs衍射卫星峰,通过拟和,MQWs结构中阱和垒的厚度分别为2.1和9.4 nm,Al组分分别为0.48和0.54.在AFM表面形貌图上,可以观察到清晰的台阶流,表明MQWs获得了二维生长;与此同时,MQWs结构存在一些裂缝,主要原因为AlGaNMQWs结构和下层GaN层间存在很大的应力.CL测试表明,AlGaN MQWs结构的发光波长为295 nm,处于深紫外波段,同时观察到处于蓝光、绿光波段的缺陷发光.

An asymmetric broad waveguide structure for a 0.98-μm high-conversion-efficiency diode laser

A novel asymmetric broad waveguide diode laser structure was designed for high power conversion efficiency (PCE). The internal quantum efficiency, the series resistance, and the thermal resistance were theoretically optimized. The series resistance and the thermal resistance were greatly decreased by optimizing the thickness of the P-waveguide and the P-cladding layers. The internal quantum efficiency was increased by introducing a novel strain-compensated GaAs_0.9P_0.1/InGaAs quantum well. Experimentally, a single 1-cm bar with 20% fill factor and 900 μm cavity length was mounted P-side down on a microchannel-cooled heatsink, and a peak PCE of 60% is obtained at 26.3-W continuous wave output power.The results prove that this novel asymmetric waveguide structure design is an efficient approach to improve the PCE.