Modeling and criticality evaluation of the voloxidation process

Voloxidation is a necessary process in the dry reprocessing of spent nuclear fuels. The criticality evaluation plays a considerable role in the design of voloxidation apparatus. As conservative results are always preferred in a criticality evaluation, an optimized model was built in consideration of both the geometry of voloxidation apparatus and the occurring forms of evaluation material. The criticality evaluation of fresh UO₂ fuel and PWR spent fuel were then performed by employing Monte Carlo techniques, respectively. It is demonstrated that there is no criticality risk concerning the voloxidation process dealing with fresh UO₂ or PWR spent fuel if water does not intrude into the cell. However, if water intrudes and mixes with the fuels, the subcritical mass limit is 40.1 ± 0.1 kg for fresh UO₂ and 19,155 ± 50 kg for spent fuel. The contributions of ¹H and ²³⁵U were analyzed quantitatively by the TSUNAMI code to clarify the competition between ¹H moderation effect and its dilution effect on the concentration of ²³⁵U.     

综合交通枢纽地下空间开发利用探究

该文通过探讨综合交通枢纽地下空间的开发利用优势及重要性,并对国内外综合交通枢纽典型实例进行解析,提出综合交通枢纽设计应重视功能的多元复合化、空间的立体集约化,使之形成地上地下共同高效运转的节点型综合体。同时注重交通枢纽与城市公共空间的融合,体现城市、建筑一体化发展。     

Fast Multiplication on Elliptic Curves over Small Fields of Characteristic Two

We discuss new algorithms for multiplying points on elliptic curves defined over small finite fields of characteristic two. This algorithm is an extension of previous results by Koblitz, Meier, and Staffelbach. Experimental results show that the new methods can give a running time improvement of up to 50 % compared with the ordinary binary algorithm for multiplication. Finally, we present a table of elliptic curves, which are well suited for elliptic curve public key cryptosystems, and for which the new algorithm can be used. Received 14 January 1997 and revised 4 September 1997     

雪崩光电管偏压控制电路的研制

本文分析了雪崩光电管内倍增因子与偏压的关系，介绍了偏压的虚警控制原理，所述电路适用于温度和背景光强大幅度变化的连续探测的光电系统。     

多用户电度表的设计

此多用户电度表采用电压，电流采样电路、模拟乘法器、滤波器，A／D转换器，LED显示器和单片机等部分组成，其主要功能是：可以实现在一个电度表上计量多个用户的电能使用量，其经济效益及可靠性都比较高。     

对线性调频信号雷达的噪声干扰方法研究

为了提高雷达抗干扰能力,线性调频信号雷达通常利用脉冲压缩技术,具有较强的抗常规压制噪声干扰的能力,为了有效干扰上述雷达,提出了两种噪声干扰技术,即干扰机将侦收的雷达发射信号与窄带噪声在时域进行相乘处理或卷积处理,再经干扰机功率放大后辐射的两种干扰方法.上述两种干扰方法均不需要测频和频率引导就能自动瞄准雷达信号频率,并可利用雷达脉冲压缩处理时的处理增益,降低了对干扰机发射功率的要求,较传统宽带压制噪声干扰的方法有明显优势.通过理论推导,仿真分析和试验验证,表明上述两种干扰方法对线性调频信号雷达均有显著的干扰效果.     

机构综合的超混沌相乘求解方法研究

超混沌是现代科学的主要成就之一,扩展超混沌的应用对现代科学的发展有重要意义。研究了超混沌相乘方法,首次提出了相乘超混沌求解非线性方程组新方法,并对机构综合进行了研究,给出了计算实例。该方法简单、实用,为实际机构的设计提供了多种选择方案,为机构学设计提供了全新的方法。     

An implementation for a fast public-key cryptosystem

In this paper we examine the development of a high-speed implementation of a system to perform exponentiation in fields of the form GF(2 ⁿ ). For sufficiently large n, this device has applications in public-key cryptography. The selection of representation and observations on the structure of multiplication have led to the development of an architecture which is of low complexity and high speed. A VLSI implementation has being fabricated with measured throughput for exponentiation for cryptographic purposes of approximately 300 kilobits per second.     

矩阵乘并行算法的仿真与性能分析

为了优化矩阵乘法的并行运算效率,提高流水线的性能,采用了基于Strassen算法的矩阵来运算,并通过缟码在DLX模拟的并行流水线环境中仿真运行.实验结果表明,优化后的矩阵秉算法降低了时间复杂度,减少了指令条数和运算周期,显著地提高了流水线上矩阵秉法的并行运算效率.     

一种基于加法链的快速标量乘算法

给出一种标量的串长加法链算法来提高椭圆曲线标量乘法的效率。新的标量乘算法结合底层域直接计算2Q+P、2^nR+S算法,使用大小窗口法将串长算法和滑动窗口算法结合,加法链长度、存储空间和预计算都减少,其效率比二元法提高53%,比NAF法提高47.5%,比串长算法提高46.2%,比Windows法提高42.2%。