脉冲电镀的正向电流密度对深镀能力的影响

主要通过在正反向电流比、频率、脉冲宽度一定的条件下,改变正向电流密度的大小来研究其对PCB整板电镀铜深镀能力的影响。从测得的数据可知随着正向电流密度的增大,深镀能力先变大后变小,并对这个问题进行了理论分析。     

铸铝激光熔融处理后的组织与性能

应用光学和电子显微镜及显微硬度计研究了铸造Al-Si合金经激光表面熔融处理后的组织和性能。指出,组织分熔化区、过度区和基体三层。在熔化区中树枝状先共晶α相的平均宽度由原始组织的20～40μm细化到2～3μm,同时共晶组织也被大大细化。这些变化使显微硬度值由67.4提高至109～115.     

尺寸驱动的变参设计系统研究

本研究在简介国际上先进的变参设计几种方法及优点后,叙述了一个国家863/CIMS项目:CAD/CAPP/NCP集成系统中二维尺寸驱动的变参设计子系统的构成与功能;然后着重阐述了本系统采用的尺寸驱动的变参设计思想和几何约束建立的原则,并提供了系统数据结构,最后以几个实例证明了此方法的正确性与工程实用性。     

中高频小功率电子元器件用非晶材料的开发与应用

随着电力和电子技术的飞速发展，相应的元器件向高频化，小型化，高效率和节能的方向发展，从而对元器件用材料也提出了更高要求。为此，本文概述了冶金部钢铁研究总院近年来所研究的用于开关电源，脉冲变压器，传感器，电流互感器和电感器等方面的非晶软磁合金的性能及其应用概况。     

Soliton position jitter caused by periodic amplification andself-frequency shift

The formula for soliton timing jitter due to self-frequency shift and pulse width fluctuations caused by spontaneous-emission noise has been deduced. Such timing jitter is compared with that caused by the carrier frequency shift due to spontaneous-emission noise. It is shown that the timing jitter due to the self-frequency shift can be as large as the timing jitter due to carrier frequency shift when the total transmission distance is 100 times longer than the soliton period     

Linear periodically time-varying discrete-time systems: Aliasing and LTI approximations

Linear periodically time-varying (LPTV) systems are abundant in control and signal processing; examples include multirate sampled-data control systems and multirate filter-bank systems. In this paper, several ways are proposed to quantify aliasing effect in discrete-time LPTV systems; these are associated with optimal time-invariant approximations of LPTV systems using operator norms.     

聚醚多元醇钻井液研制及应用

以新研制的多功能聚醚多元醇SYP-1为主剂,对聚合物包被剂、防塌剂和降滤失剂进行了优选实验.在此基础上,研制了一种新型的聚醚多元醇钻井液.对聚醚多元醇钻井液的抑制性、流变性、滤失造壁性、润滑性以及对油气层的保护性能进行了室内评价实验,并分析了该钻井液的作用机理.在LN3-6H井和HD4-23H井进行的聚醚多元醇钻井液现场试验表明,在钻进过程中井壁稳定,井径规则,起、下钻畅通,井下安全,测井、下套管及固井作业顺利.室内实验和现场应用表明,聚醚多元醇钻井液具有优良的防塌性和润滑性,能有效地抑制岩屑分散,起到稳定井壁和保护油气层的作用,满足复杂地质条件下钻井的需要.     

多路FM－SCM光波系统研制

介绍我们研制的多路ＦＭ－ＳＣＭ（调频副载波复用）光波系统及其性能，讨论了ＳＣＭ光波系统的噪声。该系统主要可用于多路ＣＡＴＶ光纤传输。采用Ｆ－Ｐ腔ＬＤ和ＰＩＮ－ＦＥＴ接收组件，通过系统优化，实现了接收端输出电视图象信号ＳＮＲ＞５５ｄＢ。     

Dynamic Reservation Multiple Access (DRMA): A new multiple access scheme for Personal Communication System (PCS)

To improve the spectrum efficiency of integrated voice and data services in Personal Communication System (PCS), several reservation-type multiple access schemes, such as Packet Reservation Multiple Access (PRMA), Dynamic Time Division Multiple Access (D-TDMA), Resource Auction Multiple Access (RAMA), etc., have been proposed. PRMA uses the data packet itself to make a channel reservation, and is inefficient in that each unsuccessful reservation wastes one slot. However, it does not have a fixed reservation overhead and offers shorter access delay. On the other hand, fixed reservation overhead is unavoidable in both RAMA and D-TDMA. Compared to D-TDMA and PRMA, RAMA is superior in the sense that its slot assignment is independent of the traffic load. But its implementation is difficult. With these observations, a new reservation protocol, called Dynamic Reservation Multiple Access (DRMA), is proposed in this paper. With this new protocol, the success probability of channel access is greatly improved at the expense of slightly increased system complexity. It solves the problem of inefficiency in PRMA, but without introducing the fixed reservation overhead as in D-TDMA and RAMA. In addition, it is more suited to the dynamic behavior of the integrated traffic because there is no fixed boundary between voice and data slots (which is mandatory in D-TDMA and RAMA). Our numerical results indicate that its performance is superior to the existing reservation protocols, especially in the integrated traffic scenario. Moreover, the soft capacity feature is exhibited when the traffic load increases.     

Analysis of Surface Plasmon Polariton Using Anisotropic Finite Elements

The anisotropic finite-element mesh is deployed in a vector finite-element method to numerically derive surface plasmon polaritons (SPPs) more efficiently. The superiority of the anisotropic mesh lies in the fact that SPP modes, predictably, have a sharp field variation in the surface-normal direction, whereas the variation along the surface-tangent direction is comparably gentle. A case study on metallic fiber shows that the employment of anisotropic finite elements reduces the problem size by a factor of seven.