Matrix unit cell scheduler (MUCS) for input-buffered ATM switches

This paper presents a novel matrix unit cell scheduler (MUCS) for input-buffered asynchronous transfer mode (ATM) switches. The MUCS concept originates from a heuristic strategy that leads to an optimal solution for cell scheduling. Numerical analysis indicates that input-buffered ATM switches scheduled by MUCS can utilize nearly 100% of the available link bandwidth. A transistor-level MUCS circuit has been designed and verified using HSPICE. The circuit features a regular structure, minimal interconnects, and a low transistor count. HSPICE simulation indicates that using 2-μm CMOS technology, the MUCS circuit can operate at clock frequency of 100 MHz     

苯基荧光酮类试剂在金属及合金光度分析中应用新进展

本文评述了近年来苯基荧光酮类试剂在金属及合金光度分析中应用的发展状况,显色反应的条件,以及相应光度分析方法的检测限和测定范围等。参考文献87篇。     

Eigenstructure assignment by decentralized output feedback-acomplete parametric approach

The problem of eigenstructure assignment in multivariable linear systems by decentralized output feedback is considered. By using a complete parametric solution of a generalized Sylvester matrix equation, parametric representations of both the left and right closed-loop eigenvectors and generalized eigenvectors as well as the feedback gains with respect to the closed-loop eigenvalues and two series of partially free parameter vectors are established. The obtained result does not require any conditions on the closed-loop eigenvalues, and generalizes some previous results in this area. An example shows the effect of the proposed approach     

Dynamic contributions to the DNA binding entropy of the EcoRI and EcoRV restriction endonucleases

Molecular Dynamics simulations on DNA-EcoRI and DNA-EcoRV complexes suggest that the DNA within these complexes is significantly more ordered than free DNA. Similarly, both the protein and the DNA are more ordered in the specific (cognate) DNA-EcoRV complex than they are in the non-cognate DNA-protein complex, consistent with recently proposed analogies between protein folding and sequence-specific DNA-protein recognition. Analysis of the trajectories shows that the net entropy gain upon specific binding to be the result of opposing contributions. Solvent release, which increases entropy versus configurational terms (as measured by the magnitude of the atomic fluctuations), and collective terms from tight coupling between the motions of the protein and the DNA.     

先进电子化政府基本模式及实现

电子化政府是运用信息技术创新政府服务的整合概念。建构电子政府已经成为世界范围内政府再造的新趋势。这里讨论了电子化政府基本模式及规划的内容和特点,并具体提出实现的模式、技术路径及方法。     

测量输入光窗台阶指标的指示表的选择

阐述了对近贴聚焦型微通道板像增强管中输入光窗台阶高度和平整度指标进行测量时，所用指示仪表的选择依据，并详细分析了指示表在检定过程中的误差来源，进一步计算出其合成标准不确定度和扩展不确定度，从而选定可用于测试的指标表。     

对增量CRL应用的一些研究

本文对PKIX依从系统中增量CRLs的应用进行了一些研究，包括：增量CRL的时间跨度对性能的影响及其最优选择；基于完全CRL与增量CRL检查证书状态以及构造新的完全CRL的算法。     

B－ISDN中的拥塞控制技术

Ｂ－ＩＳＤＮ是现代电信网的发展方向，拥塞控制技术则是其中的一个重要问题。由于Ｂ－ＩＳＤＮ采用新的信息传递方式──ＡＴＭ，使传统的拥塞控制方法不再适用。本文依据ＩＴＵ－Ｔ有关建议的最新内容对Ｂ－ＩＳＤＮ拥塞控制的基本思想、工作机制以及其中的主要功能作了较为详细的分析讨论，并提出了一些Ｂ－ＩＳＤＮ拥塞控制技术中尚需进一步研究的问题。     

α—当归内酯的合成及在烟草香精中的应用

α-当归内酯是一种香味成分,它具有甜香、枫械香等多种香韵,在烟草香精中有广泛的用途。本文对α-当归内酯的合成方法进行了研究,提出了一条合理可行的的工艺路线;同时通过对α-当归内酯在烟用香精中的应用试验,证明了它是一种理想的烟草香味添加剂。     

分散剂FDN对G级油井水泥作用机理探讨

采用液相电导法和酸度法研究了分散剂FDN对G级油井水泥水化速度的影响。发现FDN促进水泥的早期水化,但吸附-络合作用及磺酸根离子对Ca(OH)_2核晶过程的“毒化”作用使后期水化速度减慢。本研究证实ζ电位升高是FDN广生分散作用的主要因素。当FDN的吸附达饱和时,ζ电位达最大值,水泥浆的分散程度最大。