基于DCS上的优化指导系统

本文介绍了作者在美国引进美国的催化裂化装置ＳＰＥＣＴＲＵＭ集散系统上开发的一套优化指导系统,系统具有产品质量估计和优化指导等功能。     

Research of optical rainfall sensor based on CCD linear array

Rainfall monitoring is one of the most important meteorological observation elements for the disaster weather. The maintenance of current tipping bucket rain gauge and weighing type rain gauge is a critical issue. The optical rainfall sensor based on CCD linear array is mainly studied in this paper. Because of the maintenance-free time and good adaptability,it can be widely used in the automatic rainfall monitoring in severe environment and have a good perspective in using.     

高速模数变换芯片的微机接口

讨论了通过编写高效率软件，变换和读数同步进行，外置高速存储器和数据通道宽度匹配等方法来提高Ａ／Ｄ芯片与微机的接口速度。     

Preparation and optical properties of GaN nanocrystalline powders

Abstract

GaN nanocrystalline powders were synthesised by decomposition of gallium nitrate, followed by nitrogenising with ammonia under different temperature. X-ray diffraction (XRD) and the transmission electron microscopy (TEM) indicated that the crystallinity of the powder is improved and the average size of the GaN nanocrystallites increases from 4·8 to 23·9 nm as the temperature increases from 850 to 1050°C. The Raman spectra displayed four broadened peaks corresponding to A₁ (LO), A₁ (TO), E₁ (TO) and E₂ (high) modes of würtzite GaN respectively. Two additional modes at 252 and 421 cm^–1 attributed to boundary phonons activated by the finite size effects and octahedral Ga–N₆ bonds were observed respectively. A strong blue photoluminescence (～353 nm) was detected for room temperature measurement, indicating that the GaN nanocrystalline powders have few defects and high quality.     

Deposition process,microstructure and mechanical behaviours of RF magnetron sputtered (Ti,Al)N thin films

Abstract

Thin films of (Ti,Al)N with different Al contents were co-deposited using one Ti and one Al targets by radio frequency (RF) pulsed magnetron sputtering. Their composition, microstructure, nanohardness, surface morphology and deposition process were investigated by energy dispersive spectrometer system, X-ray diffraction, nanoindentation, atomic force microscopy and optical emission spectrum. A face cubic centred (fcc) TiN (B1) structure was found in the thin films when Al target power was low. When Al target power was increased, an additional hexagonal AlN (B4) structure appeared. With increasing Al content, the resulting films gradually changed from B1 structure to that of B4, accompanying with decrease of the lattice constant of B1 structure. Simultaneously, the preferred orientation of B4 structural thin films gradually transformed from (111) to (200). The mode of thin films transformed from island to fibre, subsequently to column with increasing Al target power. Optical emission spectrum analysis indicated that Al target surface reached non-metal sputtering mode earlier than that of Ti target under the same deposition parameters, which resulted in a lower sputtering rate of Al target than Ti target and loss of Al content in (Ti,Al)N thin films.     

数字存储示波器噪声特性的分析

以TektronixTDS2 10为研究对象 ,对数字存储示波器噪声进行了多次时域采样和频域分析 ,结果表明 ,示波器噪声是一种非零均值的带限白噪声 ,频谱很宽 ,对示波器测量误差和谱分析影响显著 ,应在高电压测试和信号数字处理时采取措施     

USTER HVI SPECTRUM检测仪应用体会

介绍了USTER HVI SPECTRUM大容量检测仪的工作原理和性能,重点分析了其在确定纤维质量和成纱质量关系方面的应用可能,叙述了USTER HVI SPECTRUM大容量检测仪的操作要点.     

地区电力系统的频率动态过程仿真

针对东北电网辽阳地区系统与主系统的一次解列事故,采用动态潮流法,进行了地区电力系统频率动态过程的仿真研究,对该地区的低频减载方案进行了分析,计算结果说明该方法可以清晰地描述电力系统的频率动态过程,为运行人员进行事故分析提供可靠的依据。