Vibrational spectroscopic studies on some 2-substituted 1,3-dithi a-2-boracyclopentanes

Infrared and Raman spectra are reported for 2-X-1,3-dithia-2-boracyclopentanes, where X = Br, Cl, Ph or NMe₂. In all cases the vibrations of the heterocyclic ring unit can be assigned in terms of C₂ symmetry, corresponding to a “twisted-ring” conformation similar to that found for the related molecule 1,3-dithiolan-2-thione. The internal modes of the B-Ph unit are in agreement with C_2v “local” symmetry, while those for B-NMe₂ suggest a considerably lower symmetry.     

Parallel CFD fire modelling on office PCs with dynamic load balancing

Parallel processing techniques have been used in the past to provide high performance computing resources for activities such as Computational Fluid Dynamics. This is normally achieved using specialized hardware and software, the expense of which would be difficult to justify for many fire engineering practices. In this paper, we demonstrate how typical office‐based PCs attached to a local area network have the potential to offer the benefits of parallel processing with minimal costs associated with the purchase of additional hardware or software. A dynamic load balancing scheme was devised to allow the effective use of the software on heterogeneous PC networks. This scheme ensured that the impact between the parallel processing task and other computer users on the network was minimized thus allowing practical parallel processing within a conventional office environment. Copyright © 2006 John Wiley & Sons, Ltd.     

为高性能信号路径选择放大器和ADC

通用模拟前端信号路径由信号源、低噪放大器(LNA)、ADC驱动器、通道滤波器、采样时钟和ADC组成,如图1 所示.