ADV-JP2000及其在数码相机中的应用

ADV -JP2000是AnalogDevice公司为新的静止图像压缩标准JPEG2000而生产的专用压缩芯片 ,该芯片可灵活应用于各种静止图像压缩场合。文中主要介绍了ADV -JP2000的工作过程 ,给出了用ADV -JP2000为处理核心的数码相机系统的设计方案     

Adaptive routing and wavelength assignment algorithm for WDM networks with uniform and non-uniform traffic model

This letter studies routing and wavelength assignment (RWA) problem in wavelength-routed wavelength-division multiplexing networks with both uniform and nonuniform traffic model. Our research shows that the potential traffic load information is a crucial factor for routing algorithm design. Based on our analysis, an adaptive RWA algorithm is proposed. The simulation shows that the proposed algorithm performs much better than other adaptive RWA algorithms.     

冷轧乳化油对带钢表面清洁度的影响

减少冷轧带钢表面残留物，可以改善成品退火表面清洁度。本研究通过两种轧制乳化油的对比使用实验，应用热重与差热分析方法，分析了乳化油的油品性能对轧后带钢表面及成品退火表面清洁度的影响。结果表明，只要在适当提高轧制油润滑性能的前提下，提高油品的热挥发性能，就能减少带钢轧后表面残留物，有效改善冷轧板表面清洁度。     

大机组振动状态监测系统功能的完善及改进

介绍了我国大机组配置监测系统的现状，以及提高大机组故障诊断精度，缩短诊断时间对机组振动监测系统的要求。分析了改进、完善现有监测系统功能的迫切性、可行性，以及应遵循的原则和途径。     

国产环丁砜在芳烃抽提装置上的应用

锦州石油化工公司芳烃抽提装置自1990年9月起使用的溶剂全部是该公司生产的、改质后的坏了砜。生产实践证明；国产环丁砜具有优良的溶解性和选择性，对设备腐蚀甚微，完全可以取代进口环丁砜应用于芳烃抽提装置，并且可实现装置的长周期平稳生产。生产中应避免氧进入装置，以免造成环丁砜的氧化降解。操作好溶剂再生塔对避免环丁砜降解产物的沉积、改善运行中环丁砜的使用性能是非常重要的。     

Computation sharing programmable FIR filter for low-power and high-performance applications

This paper presents a programmable digital finite-impulse response (FIR) filter for high-performance and low-power applications. The architecture is based on a computation sharing multiplier (CSHM) which specifically targets computation re-use in vector-scalar products and can be effectively used in the low-complexity programmable FIR filter design. Efficient circuit-level techniques, namely a new carry-select adder and conditional capture flip-flop (CCFF), are also used to further improve power and performance. A 10-tap programmable FIR filter was implemented and fabricated in CMOS 0.25-/spl mu/m technology based on the proposed architectural and circuit-level techniques. The chip's core contains approximately 130 K transistors and occupies 9.93 mm/sup 2/ area.     

一种新型非谐振型软开关交错并联Boost电路

提出一种新型非谐振型交错并联Boost零电压转换(ZVT)电路。在传统交错并联Boost拓扑基础上添加了一组由一个电感、两个电容、一个开关管、四个二极管组成的辅助网络,令主开关管实现了零电压开通与关断,辅助开关管实现了零电流开通与部分零电压关断,降低了开关损耗,提升了电路变换效率。软开关可在宽工作范围内有效实现,电路工作在连续电流模式(CCM),控制方式简明易行,辅助网络的引入没有给主开关管带来额外电流应力。通过复用部分辅助元件,提高了辅助网络利用率,减少了体积与费用;降低了开关过程中的dv/dt、di/dt,抑制了开关噪声。详细分析了电路拓扑结构、工作原理,并对主要参数进行了优化选取,最后通过实验验证了理论分析的正确性。     

基于快速放电的并联电容器开关恢复过电压抑制器

本文从并联电容器投切开关恢复过电压产生机理入手,以快速释放电容器直流残压为切入点,提出基于快速放电的并联电容器开关恢复过电压抑制新方法,并研制抑制器样机。通过单体性能、整体效果试验检验了抑制器关键性能,验证了此抑制器可快速释放电容器残压,并联电容器开关恢复过电压倍数可降至2.2倍下,减少并联电容器开关恢复过电压倍数和持续时间,达到降低开关重击穿概率效果,实际验证了并联电容器开关恢复过电压抑制器的创新性和实用性。     

Are significant inventions more diversified?

This study aims at exploring whether significant inventions are more technologically diversified or have more diverse applications, investigating whether there are any innovation laws existing in R&D activities. Based on technology co-classification analysis, we select patent dataset meets the specific standard from the worldwide patent database named Derwent Innovations Index as sample dataset. Three indicators out of four verify the proposed hypotheses, i.e., significant inventions are more diversified in terms of individual invention. The fourth indicator implies that focusing on some core technology domains maybe better for creating significant inventions when R&D activities are considered as a whole. The results are of great theoretical significance by helping us identifying the diversified characteristic laws of significant inventions; moreover, they are of crucial practical meanings to R&D work and technology innovation activities etc.     

Superconductivity Enhancement in Fe3O4 Doped YBa2Cu3O7−δ

Flux pinning can lead to the enhancement of J _c in superconductor. In order to study the effect of magnetic particles on superconductivity, the composites of (YBa₂Cu₃O_7?δ )_0.98(Fe₃O₄)_0.02 and (YBa₂Cu₃O_7?δ )_0.98(α-Fe₂O₃)_0.02 are synthesized with former sintered at different temperatures. The field-cooling measurements show that the T _c of the samples has not changed. The superconducting properties are enhanced when the samples are sintered at high temperature (750 ^°C), but suppressed for the samples without sintering or sintered at low temperature (350 ^°C). Scanning electron microscopy images show that the doped Fe₃O₄ are diffused into intergrain sites. With the increase of sintering temperatures, the grain size of the sample grows up and the flux pinning, which leads to the enhancement of J _c is formed by the addition of Fe₃O₄ nanoparticles. The extended X-ray absorption fine structure and X-ray absorption near edge structure experiments prove that after sintered at high temperatures the addition of Fe₃O₄ can induce disorder of local structures of YBa₂Cu₃O_7?δ . Also, the transition from the tetragonal phase to the orthorhombic phase is observed by the X-ray diffraction spectra. By the above analysis of experimental data, the enhancement of diamagnetic signal, which represents the superconducting properties can be attributed to the disorder enhancement of local structures and structural phase transition of the cuprates induced by the addition of Fe₃O₄.