多目标决策问题非支配解集的一种序列逼近方法

在多目标优化中,对非支配解集的估计是一项非常重要的工作.本文给出一种序列逼近非支配解集的方法.     

调整我国产业结构的若干思考

在国有企业产权制度改革中，改革不合理的产业结构是主要内容之一。不合理的产业结构带来了资产流量与存量产出效益的巨大损失，并放大了市场信号的失真度。因此强化产业结构的调整，是深化经济体制改革，使国民经济持续发展的保证。本文在分析产业结构不合理现状的基础上，提出了对调整我国产业结构的见解。     

单齿泵削角的优化设计

给出了单齿泵削角的优化模型与计算实例，并对理论设计与实验进行了比较分析。     

离心泵叶片边界层方程的解析解

给出了离心泵叶片表面的边界层动量积分方程的解的构造及其计算方法，并以计算实例说明了该解的唯一性和算法的稳定性、收敛性。它是分析离心泵流体在叶片表面边界层参数的基础。     

微机模拟处理pH络合滴定法研究——Ⅱ.终点确定方法和最佳实验条件模拟估计程序

本文利用简便的滴定过程模型,确立了微机模拟处理实验数据,方便、准确地求解络合滴定等当点的方法。设计了最佳实验条件模拟估计程序。该法测定Zn~(2+),Pb~(2+),Cu~(2+),Fe~(3+)结果的相对误差Δ<1％。pH=6-7时,测定Ca~(2+)的相对误差为-1.61％;σ<0.001mmol,(N=5)。     

中国油田堵水技术综述

本文论述了我国油田堵水技术的发展及其在油田开发中的作用,总结和阐述了油井化学堵水技术和注水井吸水剖面调整技术的原理和效益,指明了实践证实的有成效的工艺方法和堵水技术发展方向。     

Effect of nitrocarburizing on sulphide layer during nitrocarburizing-sulphurating treatment

Compared with the single sulphurating treatment, the duplex treatment of nitrocarburizing-sulphurating can more effectively improve the properties of steel such as friction-reducing, wear resistance and anti-scuffing. Under the same processing parameters, the sulphide layers were fabricated on the surface of CrMoCu alloy cast iron by single ion-sulphurating treatment and nitrocarburizing-sulphurating duplex treatment, respectively. Through the analysis of the sulphide, the effect of the nitrocarburizing on the fabrication of the sulphide layer was investigated. And the result shows that the fabrication of sulphide layer is promoted by the nitrocarburizing treatment.     

Reversible watermarking scheme with image-independent embedding capacity

Permanent distortion is one of the main drawbacks of all the irreversible watermarking schemes. Attempts to recover the original signal after the signal passes the authentication process are being made, starting just a few years ago. Some common problems, such as salt-and-pepper artefacts owing to intensity wraparound and low embedding capacity, can now be resolved. However, some significant problems remain unsolved. First, the embedding capacity is signal-dependent, i.e., capacity varies significantly depending on the nature of the host signal. The direct impact of this is compromised security for signals with low capacity. Some signals may be even non-embeddable. Secondly, while seriously tackled in irreversible watermarking schemes, the well-known problem of block-wise dependence, which opens a security gap for the vector quantisation attack and transplantation attack, are not addressed by researchers of the reversible schemes. This work proposes a reversible watermarking scheme with near-constant signal-independent embedding capacity and immunity to the vector quantisation attack and transplantation attack.     

Synthesis of Nearly Monodisperse Iron Oxide and Oxyhydroxide Nanocrystals

Uniform magnetite, hematite, and goethite nanocrystals were prepared through an attractive method based on an oleic acid/alcohol/water system. By adjusting the synthetic parameters (base concentration, alcohol content, categories of alcohols, etc.), the controlled synthesis of uniform magnetite, hematite, and goethite nanocrystals can be easily achieved. Detailed investigations on the effect of the experimental parameters on the morphology of the final products and the phase transitions among the magnetite, hematite, and goethite phases were carried out. Finally, a method of doping other metal ions into magnetite was developed and the magnetic properties of magnetite doped with different metal elements were studied.