双基区大功率快恢复二极管的研究

提出了在采用VB=94ρ0n.7数学模型设计双基区p+pinn+结构快速软恢复FRD大功率二极管结构参数中引入η=Wi/Xm=0.25数学模型的方法。采用Si片扩铂和电子辐照共同控制基区少子寿命及分布,并利用该设计方法对ZKR1 000 A/2 600 V结构参数进行了优化设计。对设计参数进行了实验验证,结果表明,器件参数满足设计指标,达到国外同类产品水平。说明该设计方法及各种参数的选取是正确的,寿命控制技术是有效的。为p+pinn+结构二极管设计与制造提供了一种具有重要的指导意义和参考价值的新方法。     

一种新的低复杂度基于变换域的图像差错掩 盖算法

针对图像视频在分组交换传输中的分组丢失问题，提出了一种低复杂度的、基于变换域的图像差错掩盖算法。在编码器端，采分级编码技术，根据其对图像质量影响的大小将数据分成具有不同传输优先级的两组；在解码器端、根据丢失图像块的性质，以及预测方法得到的阈值对其进行有效的差错掩盖。模拟结果显示，本算法有着更好的视觉质量以及更低的计算复杂度。     

Disconnected Processes, Mechanisms and Architecture for Mobile E-Business

With the tremendous advances in hand-held computing and communication capabilities, rapid proliferation of mobile devices, and decreasing device costs, we are seeing a growth in mobile e-business in various consumer and business markets. In this paper, we present a novel architecture and framework for end-to-end mobile e-business applications (e.g., point of sales). The architecture takes into consideration disconnection, application context, synchronization, transactions and failure recovery modes to provide mobile users with seamless and transparent access to business transactions and business-context specific data. In our architecture, we consider a novel business process design based on state-machines and event management to handle disconnection, resource limitations and failures. We designed, implemented and deployed a system for mobile e-business on clients (e.g., PDAs and PocketPCs) integrated with private exchanges and sell-side servers. The state-machine model with failure recovery mechanisms enables handling of one-to-many and many-to-one disconnections in large mobile e-business environments. The e-business framework on mobile clients is implemented based on J2ME, Webservices, and open XML standards. A detailed performance study of commerce transactions was done on different mobile client devices with diverse computing, memory and storage capabilities. We compare the performance of a purchasing application and the middleware on various devices such as PDAs and Laptops. We demonstrated that for small devices with limited capability the performance is reasonable. For devices with more computing capability, the response time is excellent.     

MICROBE-METAL-INTERACTIONS FOR THE BIOTECHNOLOGICAL TREATMENT OF METAL-CONTAINING SOLID WASTE

In nature, microbes are involved in weathering of rocks, in mobilization of metals from minerals, and in metal precipitation and deposition. These microbiological principles and processes can be adapted to treat particulate solid wastes. Especially the microbiological solubilization of metals from solid minerals （termed bioleaching） to obtain metal values is a well-known technique in the mining industry. We focus here on non-mining minerai wastes to demonstrate the applicability of mining-based technologies for the treatment of metal-containing solid wastes. In the case study presented, microbial metal mobilization from particulate fly ash （originating from municipal solid waste incineration） by Acidithiobacilli resulted in cadmium, copper, and zinc mobilization of 〉80%, whereas lead, chromium, and nickel were mobilized by 2, 11 and 32%, respectively. In addition, the potential of HCN-forming bacteria （Chromobacterium violaceum, Pseudornonas fluorescens） was investigated to mobilize metals when grown in the presence of solid materials （e.g.,copper-containing ores, electronic scrap, spent automobile catalytic converters）. C. violaceum was found capable of mobilizina nickel as tetracyanonickelate from fine-grained nickel powder. Gold was microbially solubJlized as dicyanoaurate from electronic waste. Additionally, cyanide-complexed copper was detected during biological treatment of shredded printed circuit-board scraps. Water-soluble copper and platinum cyanide were also detected during the treatment of spent automobile catalytic converters.     

一种高效的Internet上语音包丢失恢复技术

提出了一种高效的Internet上语音包丢失恢复技术,采用了基于奇偶校验码的加载式前向纠错编码(PPFEC)技术,可以在网络存在丢包情况下无损恢复大部分丢失帧信息。此外,本文将PPFEC技术与语音编码的错误隐藏技术相结合,提出了一种基于保护重要信息的FEC编码,得到更优的解码质量和带宽的性能折衷。客观音质实验表明,本文方法在各种丢包率情况下表现出良好的效果。     

Recovery from control plane failures in GMPLS‐controlled optical networks

The health status of the control plane and the data plane of a GMPLS‐controlled optical network is independent in the physically separated control network implementation. In most control plane designs, besides the topology information, the entities of the routing protocol only record the number of available wavelengths on each link. However, the status of each wavelength is maintained by the entities of the signalling protocol. Without recovery ability of the signalling protocol CR‐LDP, a failure in the control plane will result in the permanent loss of the status information of wavelengths. A mechanism to recover the status information of the wavelengths is proposed. A downstream node maintains a label information database (LID) about assignable (free) labels in each incoming link. A copy of LID is redundantly stored in the upstream node as a label information mirror (LIM). A systematic procedure is proposed to synchronize the contents of a LIM and the corresponding LID. The initialization of a new LDP session with the enhanced recovery mechanism will guarantee the revival of the status information of wavelengths. It can recover multiple control channel failures, but it only applies to single node failure among any pair of adjacent nodes. © Crown copyright 2002. Reproduced with the permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd.     

钟控准静态能量回收逻辑电路

钟控准静态能量回收逻辑 (clocked quasi- static energy recovery logic,CQSERL)只在输入信号导致输出状态发生变化的情况下才对电路节点充电 (或者回收 ) ,不需要在每个功率时钟周期循环充电和回收操作 ;CQSERL是单端输入输出逻辑 ,减小了电路实现代价 .设计了 4位 QSERL 串行进位加法器 (RCA)电路 ,和相应的 CMOS电路进行了功耗比较 .功率时钟为 10 MHz时 ,CQSERL 电路功耗是对应 CMOS电路的 35 % .流片实现了一个简单结构的正弦功率时钟产生电路 ,功率时钟的频率和相位与外接系统时钟相同     

Comparative analysis of the effects of internal lasing oscillation and external light injection on semiconductor optical amplifier performance

One of the key differences of a semiconductor optical amplifier (SOA) with internal lasing oscillation (ILO) from a SOA with external light injection (ELI) lies in a carrier-sharing mechanism. Since the internal lasing mode shares the same pool of carriers with the signals, the carriers (or photons) withdrawn from the circulating laser mode speed up the gain recovery. On the other hand, the external light injected into the SOA shortens the carrier recovery time through optical pumping without any carrier sharing involved. To find out a better scheme, we have made a comparative investigation on the effects of the ILO and ELI on the SOA performance. It turns out by way of simulation that the ELI scheme provides faster gain recovery, shorter carrier lifetime, and higher saturation power when the external injection power is higher than the internal lasing power. The performance enhancement is not so pronounced with the carrier-sharing mechanism, as the internal lasing mode itself gives rise to severe longitudinal spatial hole burning (LSHB). Nevertheless, the ILO scheme is preferable for linear-amplification applications. We also examine the use of the ELI for low-crosstalk optical amplifiers. It is found that the ELI scheme does not bring in a very strong resonance peak in the crosstalk, which appears in a SOA with ILO due to relaxation oscillations of the lasing mode. In comparison to the ILO in SOAs, the ELI into SOAs is likely to leave more optical gain for multi-channel amplification without any sacrifice on the crosstalk.     

用于能量回收逻辑的正弦功率时钟电路

分析了功率时钟对电容负载充电与回收的物理过程，研完了正弦功率时钟产生电路的基本结构，考虑了功率时钟的频率与相位的稳定性。在此基础上，提出了稳定功率时钟频率与相位的功率时钟产生电路，即接入外部参考时钟，使振荡电路与参考时钟同步。用0．8μm DPDM CMOS工艺实现了一个简化的两相正弦功率时钟产生电路，通过物理测试，验证了电路的工作原理。     

Scaling Immiscible Displacements in Porous Media with Horizontal Wells

Despite the increase in horizontal well applications, scaling fluid displacement in porous medium with horizontal wells is yet to be fully investigated. Determining the conditions under which horizontal wells may lead to better oil recovery is of great importance to the petroleum industry. In this paper, a numerical sensitivity study was performed for several well configurations. The study is performed in order to reveal the functional relationships between the scaling groups governing the displacement and the performance of immiscible displacements in homogeneous reservoirs produced by horizontal wells. These relationships can be used as a quick prediction tool for the fractional oil recovery for any combinations of the scaling groups, thus eliminating the need for the expensive fine-mesh simulations. In addition, they provide the condition under which a horizontal well configuration may yield better recovery performance. These results have potential applications in modeling immiscible displacements and in the scaling of laboratory displacements to field conditions.