活性炭的制备及应用新进展

综述了活性炭材料研究开发的新进展。重点介绍了煤、石油焦、沥青基活性炭的制备方法及针对不同用途的活性炭改性技术，为选择合适的活化方法和制备特殊功能的改性活性炭提供了参考。     

Interface Management within Construction: In Particular, Building Facade

This paper discusses the need for interface management within construction, with particular reference to building facade interfaces. It categorizes the three different types of interface management—physical, contractual, and organizational. The implication of interface management in construction contracting is discussed; it is explained how the U.K. procurement trends have changed, affecting the interface management within projects. U.K. cladding procurement is very fragmented, and the paper maps the development of a typical cladding system showing the complexities of interface management. Finally, the paper discusses CladdISS, a U.K. government funded research project to develop a standardized strategy for the design and management of window and cladding interfaces. It explains the principles of CladdISS with reference to process maps, action plans, management strategy, bibliography, advice on standards, materials, maintenance, joints, movement, and tolerances. This will enable strategies to be developed to avoid the endemic interface problems occurring on-site. It will also guide the management of the interfaces throughout the project.     

Real-world extensions to scheduling algorithms based on lagrangian relaxation

Recently, efficient scheduling algorithms based on Lagrangian relaxation have been proposed for scheduling parallel machine systems and job shops. In this article, we develop real-world extensions to these scheduling methods. In the first part of the paper, we consider the problem of scheduling single operation jobs on parallel identical machines and extend the methodology to handle multiple classes of jobs, taking into account setup times and setup costs. The proposed methodology uses Lagrangian relaxation and simulated annealing in a hybrid framework. In the second part of the paper, we consider a Lagrangian relaxation based method for scheduling job shops and extend it to obtain a scheduling methodology for a real-world flexible manufacturing system with centralized material handling. This research was supported in part by the Office of Naval Research and the Department of Science and Technology grant N00014-93-1017.     

Graph‐Theory Approach to Eigenvalue Problem of Large Space Structures

The dynamic analysis and control system design of large space structures involve the solution of the large‐dimensional generalized matrix eigenvalue problem. The computational effort involved is proportional to the third power of the dimension of the matrices involved. To minimize the computational time a graph‐theory approach to reduce a matrix to lower‐ordered submatrices is proposed. The matrix‐reduction algorithm uses the Boolean matrices corresponding to the original numerical matrices and, thus, the computational effort to reduce the original matrix is nominal. The computational savings directly depend upon the number of submatrices into which the original matrix is reduced. A free‐free square plate is considered as an example to illustrate the technique. In this example a matrix of 16th order is reduced to three scalars corresponding to three rigid‐body modes, and three matrices of order three and one matrix of order four.     

设计IIR数字滤波器的遗传优化算法

提出了ＩＩＲ数字滤波器设计的遗传优化法。这是一种模拟自然遗传和达尔文进化理论的随机并行优化算法。首先，详细描述了遗传算法并给出了计算步骤，然后将遗传算法用于ＩＩＲ数字滤波器的优化设计，最后给出了模拟计算结果。     

Reconstruction of a discontinuous function from a few fourier coefficients using bayesian estimation

The goal of this paper is the application of spectral methods to the numerical solution of conservation law equations. Spectral methods furnish estimates of the firstn Fourier coefficients of the solution. But since the solutions of conservation law equations can have discontinuities, the estimate of the solution by summing the firstn terms of the Fourier series will haveO(1/n) error, even if the Fourier coefficients are known to high accuracy. But if the solution could be accurately reconstructed from its Fourier coefficients, spectral methods could be used effectively in these problems. A method for doing this is to assume a probability distribution for functions. Functions which are smooth away from the discontinuity are assumed to be likely, and those which are not smooth away from the discontinuity are assumed to be unlikely. Then a reconstruction algorithm is chosen by minimizing the expected error over all algorithms. It is possible to put the smoothness assumptions mentioned earlier into an infinite-dimensional Gaussian probability distribution, and then the minimum-error algorithm is well-known and fairly simple to construct and apply. If the Fourier coefficients of the reconstructed function are known exactly, then this approach gives very good results. But when used with Fourier coefficients obtained from a spectral approximation to Burgers' equation, the results were much less impressive, probably because the coefficients were not known very accurately. It is possible to construct filters that reconstruct a function using Legendre or Chebyshev coefficients for information instead Fourier coefficients. It is found that the performance of these filters is similar to the Fourier case.     

溶胶－凝胶法制备Pb（Zr，Ti）O_3玻璃陶瓷过程中的结构变化

本文介绍溶胶－凝胶法制备均匀ＰｂＺｒ－Ｔｉ－Ｂ－Ｓｉ凝胶玻璃，并通过适当热处理在凝胶玻璃中原位生长Ｐｂ（Ｚｒ；Ｔｉ）Ｏ３微晶的新工艺·利用ＩＲ谱考察了凝胶玻璃中的元素键合结构随温度的变化．结合热分析和ＸＲＤ；ＳＥＭ技术，研究了Ｐｂ（Ｚｒ，Ｔｉ）Ｏ３微晶在凝胶玻璃中的生长过程及该材料的结构特点．发现Ｐｂ２（Ｚｒ，Ｔｉ）２Ｏ６＋ｘ立方焦绿石介稳过渡相的纳米微晶首先出现于该体系中，并在更高的温度下先后完全转变成三方和四方Ｐｂ（Ｚｒ，Ｔｉ）Ｏ３钙钛矿相．电子显微观察结果表明，该工艺制备的Ｐｈ（Ｚｒ；Ｔｉ）Ｏ３玻璃陶瓷具有均匀的细晶结构．     

An Object-Oriented Transaction Model

In object-oriented database systems(OOBSs),the traditional transaction models are no longer suitable because of the difference between the object-oriented data model(OODM)and the conventional data models(e.g.relational data model).In this paper,transction models for advanced database applications are reviewed and their shortcomings are analyzed.Exchangeability of operations is proposed instead of commuativity and recoverability for using more semantics in transaction management.As a result,an object-oriented transaction model(in short,OOTM)is presented.It is not modeled for some special application,but directly based on object-oriented paradigms.A transaction is regarded as an interpretation of a metho.Each transaction(even subtransactions)keeps relative ACID(Atomicity,Consistency,Isolation,Durability)properties,therefore the special problems appearing in OOBSs such as“long transactions”,“visibility of inconsistent database state”can be solved.     

Formal methods: The next generation of system design tools

Because of the growing demand for increasingly complex computer-based systems there is now an urgent need to provide tools to assist during the design of such systems. Formal specifications and formal methods provide such assistance but their widespread adoption has been hindered by the so-called ‘math fear’ and the perception that the tools are too difficult, too time consuming and too costly to use in a commercial environment. The aim of this article is to dispel the mystery surrounding the topic and to explain what formal methods are, how and why they are used, the benefits that accrue and why the technology should be accepted on a broader front. The application of formal methods to the design of computer-based systems will be discussed without resorting to jargon or mathematics. The discussion will concentrate more on the software content of systems but the arguments apply equally well to hardware. Some of the available tools will also be introduced.