用MCS─51单片机测量微小周期信号

介绍了用ＭＣＳ－５１单片机对微小变化周期信号的精确测量方法、接口电路的工作原理、接口的程序设计及测量误差分析。经生产实践证明，该机达到设计要求（测量绝对误差小于０．０１μｓ）。     

复杂小断块油藏精细挖潜的实践与认识

对于八面河油田北区的开采是在精细地质研究的基础上,指导其区块扩边挖潜,以油砂体为单元,应用多种技术手段研究剩余油分布状况和天然能量评价,通过钻水平井、补孔、卡堵水、提液,注水等综合调整措施实现油藏精细管理,使该油藏自然递减大幅下降,连续五年保持稳产,对其它类似的复杂小断块油藏开发具有很好的指导意义。     

春秋战国时期用人制度变革中的政治去伦理化

用人制度的变革,是春秋战国之历史剧变的重要组成部分.用人制度变革的核心是通过制度化的方式剥离政治权力与血缘之间的联系,使双向垂直的社会阶层变动具有了合法性依据,并使一种不同于以往的政治范式———郡县制的政治体制的确立成为可能.     

Security analysis of the public key algorithm based on Chebyshev polynomials over the integer ring ZN

Recently Kocarev and Tasev [20] proposed to use Chebyshev polynomials over real numbers to design a public key algorithm by employing the semigroup property. Bergamo et al. [4] pointed out that the public key algorithm based on Chebyshev polynomials working on real numbers is not secure and devised an attack which permits to recover the corresponding plaintext from a given ciphertext. Later Kocarev et al. [19] generalized the Chebyshev polynomials from real number fields to finite fields and finite rings to make the public key algorithm more secure and practical. However, we analyzed the period distribution of the sequences generated by the Chebyshev polynomials over finite fields [21]. When the modulus N is prime, we found this algorithm was also not secure and proposed an attack on this algorithm over finite fields. We then proposed some schemes to improve the security. In this paper, we further analyze in detail the period distribution of the sequences generated by Chebyshev polynomials over the integer ring Z_N when N is composite. It turns out that the period distribution is poor if N is not chosen properly and there are many small periods, which are not secure in the sense of cryptology. Based on these findings, we devise an attack on the public key algorithm based on Chebyshev polynomials over the integer ring Z_N. We also propose some suggestions to avoid this attack.     

超声多普勒流速测量中存储容量的压缩方法

介绍了多普勒频率单片机测量时的数据处理方法，即线性地址变换法。在存储容量有效压缩的基础上，进一步分析了采样数据，用软件实现可控时标，保证了测量精度。     

Nonlinear dynamic analysis of cantilever tube conveying fluid with system identification

The vibration of a flexible cantilever tube with nonlinear constraints when it is subjected to flow internally with fluids is examined by experimental and theoretical analysis. These kinds of studies have been performed to find the existence of chaotic motion. In this paper, the important parameters of the system leading to such a chaotic motion such as Young’s modulus and the coefficient of viscoelastic damping are discussed. The parameters are investigated by means of system identification so that comparisons are made between numerical analysis using the design parameters and the experimental results. The chaotic region led by several period-doubling bifurcations beyond the Hopf bifurcation is also re-established with phase portraits, bifurcation diagram and Lyapunov exponent so that one can define optimal parameters for system design.     

基于春秋淹城的表演类职业服开发设计

以春秋淹城主题乐园奄王这一角色的表演类职业服为研究对象，深入了解历史文化背景，重点分析春秋服饰元素对春秋淹城表演类职业服设计的影响，归纳设计原则与方法，合理设计出春秋淹城表演类职业服，完善了旅游景点表演类职业服的设计理论。     

“九五”选煤研究成果对中国选煤技术的影响

回顾了“九五”课题立项背景和立题指导思想，介绍了“九五”期间选煤科学研究在５个技术领域的国家“九五”攻关和部级课题分布，重点介绍了高硫难选煤脱硫、大型高效全重介简化工艺、干法与节水型选煤、细粒煤粉选、传统技术升级运用技术等领域的研究成果内容、特点及使用范围，并分析了这些研究成果对中国选煤技术的影响及其将对选煤业的推动作用。     

在LabVIEW中处理检定有效期的方法

本文针对自动检定系统中如何处理被检器具检定有效期问题,在LabVIEW开发环境中设计了计算程序,并对子VI的创建和使用方法进行了描述,对从事自动检定系统开发者具有极高的参考、借鉴价值。     

供暖网络的节能措施——计算机实时控制系统

供暖系统运行的能耗在物业管理成本中占份额较大,是经营盈亏的重要控制点。本文通过对实际运行中记录的大量资料进行分析,针对传统的供暖系统运行方式的缺陷,旨在为提高能源的转换效率,最大限度地降低运行成本,提出了用计算机分区域、分时段、分换热方式和分温度梯度等实时变频控制的全新系统控制理论。