Corrosion Behavior of a Sputtered K38G Nanocrystalline Coating with a Solid NaCl Deposit in Wet Oxygen at 600 to 700°C

A nanocrystalline coating of K38G alloy was obtained by means of magnetron sputtering. The corrosion behavior of cast K38G alloy and its sputtered nanocrystalline coating with a solid NaCl deposit in dry air or wet oxygen at 600 and 700°C have been studied and compared. The results indicated that the mass gain of the coating is higher than that of the cast alloy at 600 and 700°C. Therefore, nanocrystallization reduced the corrosion resistance at these temperatures. Furthermore, the mass gains of the coating and the cast alloy with a NaCl deposit in wet oxygen were less than that with a NaCl deposit in dry air. The relevant corrosion mechanisms are discussed.     

Nested multigrid vector and scalar potential finite element method for fast computation of two-dimensional electromagnetic scattering

Nested multigrid techniques are combined with the ungauged vector and scalar potential formulation of the finite-element method to accelerate the convergence of the numerical solution of two-dimensional electromagnetic scattering problems. The finite-element modeling is performed on nested meshes of the same computational domain. The conjugate gradient method is used to solve the resultant finite-element matrix for the finest mesh, while the nested multigrid vector and scalar potential algorithm acts as the preconditioner of the iterative solver. Numerical experiments are used to demonstrate the superior numerical convergence and efficient memory usage of the proposed algorithm.     

Access-mode predictions for low-power cache design

An access-mode prediction technique based on cache hit and miss speculation for cache design-achieves minimal energy consumption. Using this method, cache accesses can be adaptively switched between the way-prediction and the phased accessing modes.     

淬透性曲线应用系统的开发与应用

介绍利用VISUAL BASICA6.0在计算机上建立各种常用钢种淬透性曲线的软件开发,以及利用淬透性曲线和所建立的数据库自动完成淬透性曲线在各种应用中的相关计算的功能。     

A hybrid PC/PLC architecture for manufacturing-system control—theory and implementation

This paper presents a novel and generic PC/PLC-based software/hardware architecture for the control of flexible manufacturing workcells. The proposed implementation methodology is based on the utilization of any one of the available formal discrete-event-system control theories in conjunction with state-of-the-art industrial programmable-logic controllers (PLCs). The methodology has been illustrated to be a viable technique through its actual implementation in our laboratory using a robotic-workcell testbed. The specific control theory used is a combination of Extended Moore Automata and Ramadge-Wonham Automata that has been developed by our research group. The modular control software architecture has been developed for MS-Windows environments (running on one PC interfaced to the PLCs) and allows the use of different formal control theories as well as different commercial PLC hardware. The effective graphical user interface provides a transparent programming environment, where users are not expected to have a full knowledge of the formal control theory used.     

注重产品创新提高经济效益

从煤炭销售市场角度,论述了煤炭企业应大力发展产品深加工,增加配煤技术应用,满足用户要求,提高经济效益.     

A simple method for measuring the cell gap of a reflective twisted nematic LCD

A simple method is demonstrated for measuring the cell gap of reflective twisted nematic (RTN) liquid crystal (LC) cells. This method utilizes a single laser beam and crossed polarizer configuration such that Fabry-Perot effect and surface reflection are eliminated. Experimental results agree well with theory.     

Hybrid multilevel/multigrid potential preconditioner for fast finite element modeling

A robust hybrid multilevel/multigrid potential preconditioner is introduced for the fast and robust finite-element modeling of electromagnetic structures. The proposed preconditioning process combines the advantages of the hierarchical multilevel preconditioner and the nested multigrid potential preconditioner into a novel preconditioner with superior computational versatility. Numerical experiments from the application of the new preconditioner to the finite-element analysis of microwave devices demonstrate its superior numerical convergence and efficient memory usage.     

高效率窄线宽光纤激光器

本文报道了一种环形腔掺饵光纤激光器，得到了泵浦效率高达22.6%，输出线宽小于0.1nm的激光输出。     

最大熵在感应测井反演中的应用

常规的反演方法是对感应测井资料进行线性反褶积。由于感应测并获得的响应曲线是地层非线性时变滤波的结果,感应测井响应随地层电导率发生非线性变化。本文把熵的概念引入到感应测井反演中。用最大熵方法分别设计出实部信号和虚部信号所对应的反滤波因子,两条反映测井响应随电导率非线性变化的非线性函数也被拟合出来。文章最后用设计出的滤波因子及被拟合出的非线性函数对模拟相量感应测井资料进行了相量反褶积。处理结果表明,围岩效应和趋肤效应基本被消除。本方法与常规的三点反褶积法相比,克服了过聚焦现象,提高了精度。