Synthesis of silica nanocubes by sol–gel method

A novel approach was employed in the fabrication of silica nanocubes with controlled size and shape. The silica nanocubes were highly dispersed with width of about 30 nm and product with high purity. A small amount of tartaric acid was introduced in the TEOS hydrolysis process. In this work tartaric acid as the organic template, was formed on the surface of hydrous silica colloidal particles. The organic template ordered by carboxyl, led to the self-assembly of amorphous silica sol encapsulated into cubic matrixes, and the organic template was packed into 3D structure.     

Real-time display and development of an aerometric data base for a field experiment

An innovative data center responsible for collecting, displaying, and analyzing near real-time meteorological and air quality measurements from a variety of sources was operated in Camarillo, California, during September–October 1985. This data center was part of a multi-million dollar study conducted for the South Central Coast Cooperative Monitoring Program sponsored by the Western Oil and Gas Association, a consortium of petroleum and fuel-producing organizations, to gain a better understanding of air quality conditions in the southern California coastal areas, and to produce a comprehensive data base for which coastal air quality models could be developed and evaluated.Led by the Atmospheric Science Center of SRI International, the program included a large number of contractor organizations responsible for collecting air quality measurements from land, sea, and air instrumentation for future analysis and model development. The data center integrated near real-time air quality and meteorological data with weather services forecasts to develop day-to-day environmental predictions governing the data collection activities.     

芦山地震中大跨空间结构主要破坏模式及数值分析

为探究短边距混凝土网架平板支座的受力机理和破坏模式,分别针对不同混凝土边距以及不同钢底板开孔形式共3个平板支座缩尺试件进行拟静力试验。对平板支座试件的破坏模式、滞回曲线、混凝土柱上层箍筋应变进行分析。试验结果表明：采用规范中对抗剪锚筋混凝土边距的建议长度,不能避免支座混凝土边缘破坏发生,但是混凝土柱上层箍筋对混凝土边缘的约束作用明显,并且采用开长孔钢底板并合理设计开孔长度,能有效推迟甚至避免发生混凝土边缘破坏。     

Toward a social conflict evolution model: Examining the adverse power of conflictual social interaction in online learning

This case study examined an authentic online learning phenomenon where social conflict, including harsh critique and negative tone, weaved throughout peer-moderated online discussions in an online class. Opening coding and content analysis were performed on 1306 message units and course artifacts. The results revealed that a model of social conflict evolution, that is, social conflict within the learning community evolved through five general phases including cultural initiation, social harmonization cycle, escalation of conflict, intervention and stabilization, and adjourning. The results also suggested strong relationships between social and learning interactions during these five phases of social conflict development. This study has theoretical and practical implications for designing and managing learning activities in online classes.     

影响电网安全运行的各类故障及其相应对策

在统计分析了近10年来全国电网运行各类故障的基础上,对当前电网事故发生的特点和规律进行了分析总结,指出了制约电网安全运行的主要因素,并提出了相应的对策。     

纤维素纤维技术现状与发展

扼要论述了Lyocell、醋酯纤维以及传统粘胶纤维的纺制技术现状和发展趋势,对这几种纤维素纤维在中国的发展提出了几点看法,认为应该通过Lyocell纤维的研究实践锻炼出一支技术队伍,积极开发国产化纺织用醋酯纤维,严格限制传统粘胶纤维生产的短视性扩张。     

Characterization of an optical frequency-shift-keying transmitter based on carrier-suppressed phase modulation

We experimentally characterize an optical frequency-shift-keying transmitter based on optical carrier-suppressed phase modulation. Only one laser source is needed to generate an optical FSK signal. The demonstration of 10-Gb/s FSK signal generation and 50-km transmission verified the improved performance of the proposed transmitter, compared with the previous two-laser schemes. To further reduce the complexity of the transmitter, the phase modulator is omitted and a single MZM modulator is used for both optical carrier-suppression (OCS) and phase modulation. This simplified structure is verified by simulation, implying the feasibility that a FSK transmitter can be constructed with only one laser source and one modulator.     

激光技术在录井工程中的应用进展及展望

为实现在录井现场对岩性和油气快速、自动识别以及对孔隙快速分析成像,引入了激光技术。从激光技术在实现岩性、油气检测和孔隙成像中的关键因素着手,对激光器选择、发射波长选取、拉曼效应放大和重组分拉曼光谱分离等方面进行了适应性技术研究,形成了激光诱导击穿光谱岩性识别技术、激光扫描共聚焦储集性能评价技术和拉曼激光油气实时评价技术。应用表明,利用激光技术检测岩性平均符合率达88.0%,孔隙度分析最大误差7.9%,气体组分检测分辨率达百万分之一,与同类录井技术相比具有分析快速、数据准确和操作简便等优点。研究认为,通过激光技术在录井现场的适应性研究,增强了录井工程在岩性和油气快速识别、孔隙结构分析等方面的能力,为智能录井提供了一种新的技术手段。      

二次量化技术在像素级数字积分探测系统中的应用研究

像素级数字积分探测是一种新型的红外探测技术,其具备电荷处理能力高、动态范围大等特点,能够有效提升红外系统探测灵敏度,在各类红外弱信号探测领域具有巨大的应用潜力。像素级数字积分技术中的二次量化技术,可对在总噪声中占比较大的量化噪声进行有效抑制。对像素级数字积分探测系统中的量化步长进行优化设计以及对二次量化技术进行研究,分析量化步长的改变对像素级数字积分红外探测系统性能的影响;分析二次量化的原理及特点,研究其在应用中的关键参数设计,从而推动二次量化技术的发展,实现像素级数字积分探测系统更高灵敏度探测应用。     

利用光纤拉曼散射温度传感系统的电力电缆温度在线监测

电力电缆线路运行温度在线检测技术是目前及时发现电力电缆线路局部过热点位置、检测运行线路的绝缘状态和计算导体载流量的首选技术措施。分布式光纤拉曼测温技术是利用激光在光纤中的传播特性,实现实时测量空间温度场分布的新技术,可以对光纤沿线的温度场进行分布式的连续检测。介绍了光纤拉曼传感技术的测温原理,以及基于此技术的电力电缆温度在线监测系统在实际中的应用,获得了一些仿真结果,并同传统的测温技术进行了详细的比较,说明分布式光纤拉曼测温系统应用于电力电缆在线监测的优势,适合于推广使用。