提高基因算法求管网经济管径计算效率的尝试

在用基因算法求给水管网经济管径的课题中，试用管径系列直接编码、引入特定的初始解、采用动态的评价函数、保护最优个体等方法，在简化计算机编程，提高计算效率方面作了尝试，并对算例的结果作了验证和对比。     

海上电子设备三防技术

本文根据我国海上用雷达等电子设备“三防”性能和存在的问题以及国外电子设备“三防”的状况找出差距。针对实际要求,论证军用电子装备“三防”的必要性和急需解决的关键技术及措施。     

Development of a Structured Methodology for Knowledge Elicitation: Applications to Flexible Manufacturing Systems

While automation in the discrete parts manufacturing industry has increased productivity and improved product quality it has also significantly altered the role played by the operator of the system. The operators' role has not only become more critical to the effective functioning of the system but also causes mental overload and imposes greater demands on humans' information processing capabilities. This paper examines methods by which the mental overload experienced by operators can be alleviated while sustaining improvements in productivity and product quality. Additionally, the possibility of reducing mental overload by training and aiding the operator and effecting a more optimal allocation of function using dynamic allocation of function schemes is reviewed. It is concluded that a prerequisite to using the above methods to reduce mental overload is the ability to build appropriate decision support systems. A methodology that allows the development of such decision support systems is described and results of a study to evaluate the methodology are presented.     

Computer study of tweed as a precursor to a martensitic transformation of a Bcc lattice

Using molecular dynamics computer simulations we have studied a bcc crystal with an interatomic potential having a second derivative which passes through zero near second neighbor distances. This causes an inherent tetragonal instability which manifests itself as random dynamic tetragonal distortions at high temperature (“dynamic tweed”), quasi-static and somewhat spatially correlated tetragonal distortions at intermediate temperatures (“static tweed”), and an apparent martensitic transformation to a close-packed structure at low temperatures. The effect of simple defects (vacancies and interstitials) on the development and spatial localization of the pretransformation structure (tweed) and the subsequent martensitic transformation will also be discussed. This paper is based on a presentation made in the symposium “Pretransformation Behavior Related to Displacive Transformation in Alloys” presented at the 1986 annual AIME meeting in New Orleans, March 2–6, 1986, under the auspices of the ASM-MSD Structures Committee.     

Optimal Depreciation Policy Under the Tax Reform Act of 1986

Mathematical expressions for allowable depreciation are developed for the Modified Accelerated Cost Recovery System (MACRS) as well as the allowed alternate method (AMACRS), two capital recovery methods permitted under the Tax Reform Act of 1986. The choice between MACRS or AMACRS is rigorously analyzed with respect to normal asset disposition, premature asset disposition, monotone decreasing tax rates and monotone increasing tax rates. Conditions under which either MACRS or AMACRS is optimal are specified, and the economic value of the optimal policy is determined. Numerical illustrations are provided throughout the paper to demonstrate the underlying methodology.     

A Sustainable Funding and Financing Strategy for Urban Infrastructure Renewal in China

In a relatively short time, many of China’s cities have become major industrial, shipping, and financial hubs. To support this unprecedented growth and economic development, China has invested enormous sums to provide transportation, power, communications, sanitation, and other basic infrastructures. Although much of this investment has been in newer urban districts, old districts within existing cities still add value to the economy and are often repositories of China’s considerable cultural heritage. Maintaining compatibility between the old and the new is always challenging but the renewal of older infrastructure systems often lags behind due to a shortage of capital and difficulties in raising sufficient revenue to support replacement and upgrading of basic systems. This paper will examine the range of funding and financing options that are in use throughout the world to see what mix of public and private approaches might be most suitable for Chinese cities to adopt as part of a funding and financing strategy that will support enduring and sustainable renewal and redevelopment of older urban districts.     

Effect of bisphosphonates on the stimulation of macrophages by alumina ceramic particles: A comparison with ultra-high-molecular-weight polyethylene

Wear particle-induced osteolysis and loosening is a critical process that limits the longevity of total hip arthroplasty. Despite their potential value in the management of aseptic loosening, little is known about the cellular response to bisphosphonates (BPs) in the presence of particulate debris. In the present study, we compared the effect of pamidronate and clodronate, two structurally different bisphosphonates, on the induction of TNF-α release by alumina ceramic (Al₂O₃) and ultra-high-molecular-weight-polyethylene (UHMWPE) particles. We also looked, by Trypan blue exclusion, at the viability of J774 mouse macrophages incubated with Al₂O₃ and UHMWPE particles in combination with pamidronate or clodronate. Results showed that pamidronate and clodronate can inhibit UHMWPE particle-induced TNF-α release while they had no effect on Al₂O₃-stimulated TNF-α release. The co-incubation of pamidronate or clodronate and Al₂O₃ had no effect on the induction by Al₂O₃ of poly(ADP-ribose)polymerase (PARP) proteolysis and DNA fragmentation. On the other hand, UHMWPE particles had no effect on these apoptotic markers. However, the co-incubation of pamidronate or clodronate with UHMWPE particles led to the appearance of these markers of apoptosis. Al₂O₃ and UHMWPE particles had no effect on macrophage cell death or the number of macrophages at the end of experiments. Co-incubation of UHMWPE particles with pamidronate and clodronate led to a significant increase in cell death. Interestingly, the number of macrophages co-incubated with particles and pamidronate or clodronate significantly decreased. In conclusion, our results suggest that the effect of BPs on particle-stimulated macrophages is, at least in part, particle composition dependent.     

中外科学技术发展比较研究

21世纪是科学技术飞速发展的世纪，论述了世界科学技术近年来的发展趋势，分析和对比了中外科学技术应用研究与发展情况，指出了实施科教兴国战略是加快我国科学技术发展的一条根本出路。