智能变电站的关键技术及应用实例

分析了智能电网的发展目标,介绍了智能变电站的功能和系统结构,整个智能变电站可分为过程层、间隔层、站控层以及网省的生产管理系统等部分。提出了建设智能变电站的几个关键技术:一次设备智能化、信息网络化以及在线监测。借鉴IEC61850中功能自由分配的概念,对变电站的各种功能进行了分析和合并,将智能变电站的过程层和间隔层合并为设备层,提出了一种面向未来,适应智能电网要求的智能变电站体系结构。     

输电线路导线微风振动在线监测技术

为有效避免由输电线路导线微风振动引起的导线断股事故,设计了一套微风振动在线监测系统来实时监测导线的微风振动信息。系统采用悬臂梁式传感器测量导线的弯曲幅度,并根据弯曲幅度,采用峰峰值法和快速Fourier变换(FFT)等方法,计算出导线振动的频率与振幅以及导线的动弯应变。研究表明,悬臂梁式传感器可以准确测量频率1～150Hz的小幅振动信号,峰峰值法可以准确计算出导线微风振动的振幅,而快速Fourier变换可以准确计算出导线振动的频率。根据研究结果可知,该系统采用的测量方法和建立的数学模型可以准确计算出导线的动弯应变值,并能实现输电线路疲劳故障的预警。     

开关电源中磁集成技术及其应用

回顾了磁集成技术的发展历史,介绍并简要分析了目前磁件的等效电路模型及建模方法,从磁心特性、磁集成的通用方法以及不同的磁集成对象三方面对磁集成技术的主要应用研究内容进行了概括分析,总结了磁集成技术的多解性特点、常用的磁集成方式以及磁集成应用的限制。     

PLC与多传感器融合的室内空气净化设备的控制设计

在医院、商场、火车站等需要保持空气洁净的室内空间中,需要在单位时间内对大量的空气进行净化和消毒处理.对此,介绍一种室内空气净化设备的设计细节,为国内相关系统的设计与研究提供一些依据和借鉴.该系统使用大功率风机,提高单位时间的风量,快速降低PM2.5;采用可编程逻辑控制器(Programmable Logic Contr...     

C6H11NO/2TsOH型低共熔溶剂的制备及其催化氧化脱硫性能

通过加热溶解己内酰胺和对甲苯磺酸的混合物制备CC₆H₁₁NO/2TsOH型低共熔溶剂(DESs),并对 C₆H₁₁NO/2TsOH进行红外和氢谱分析。以C₆H₁₁NO/2TsOH为萃取剂和催化剂,H₂O₂为氧化剂,催化氧化脱除模拟油中的硫化物。考察了反应温度、n(H₂O₂)/n(S)、C₆H₁₁NO/2TsOH用量和不同硫化物类型对脱硫效果的影响。结果表明：在低共熔溶剂加入量为1.0 g、温度为60 ℃、n(H₂O₂)/n(S)=4、模拟油体积为5 mL的反应条件下,C₆H₁₁NO/2TsOH对二苯并噻吩(DBT)、4,6-二甲基二苯并噻吩(4,6-DMDBT)和苯并噻吩(BT)的脱除率分别为97.32%、86.60%、77.80%;C₆H₁₁NO/2TsOH循环使用5次,催化活性无明显下降;动力学分析表明,作用下的氧化脱硫过程符合一级反应动力学。     

Gelation properties of goose liver protein recovered by isoelectric solubilisation/precipitation process

Isoelectric solubilisation/precipitation (ISP) process was applied to goose liver (GL) for protein extraction. The gelation properties of proteins extracted by acid processes (ACP, pH 2.0, 2.5 and 3.0) and alkaline processes (ALP, pH 11.0, 11.5 and 12.0) were estimated, where the unextracted ground GL was set as the control. Nearly 58.39~79.00% of GL proteins were recovered by ISP treatments. High molecular weight (100~250 kDa) proteins were found to be partially hydrolysed by ACP, while few changes in proteins occurred during ALP. As evidenced by rheological and textural measurements, ALP proteins formed gels with high elasticity and superior texture, whereas ACP proteins had inferior gelation properties. Moreover, ALP proteins were able to form a highly interconnected and homogeneous three‐dimensional microstructure. Predominantly, gels produced by 11.0 had optimal texture and the lowest cooking loss (P < 0.05). These results suggested that the ISP process (ALP) is a potential method to improve the economic value of GL.     

Nanoporous copper sonocatalysts prepared by dealloying Cu–Al–Ti amorphous ribbons

ABSTRACT

Nanoporous copper (NPC) with a controllable ligament width was prepared by chemically dealloying Cu₄₅Al₄₅Ti₁₀ amorphous ribbons in dilute HCl solution. X-ray diffraction and scanning electron microscopy analysis confirmed the 3D, bicontinuous, nanoporous structure constituting fcc-Cu ligaments of 39–79?nm thickness. The coarsening of NPC ligaments increased significantly with an increase of HCl concentration, reaction temperature or time. The surface diffusivity and activation energy of NPC were also calculated. Finally, the catalytic activity of NPC was validated with the ultrasound and H₂O₂-assisted degradation of methyl orange (MO), where 99% MO was degraded within 15?min.     

高岭土制备复合絮凝剂聚合氯化铝铁的研究

以高岭土为原料,经高温焙烧,酸溶,水解,聚合等步骤,制备了复合絮凝剂聚合氯化铝铁。考察了焙烧温度、时间、酸溶温度、酸溶时间、液固比对铝铁溶出率的影响,并确定了最佳聚合条件。絮凝实验表明,制备的聚合氯化铝铁具有很好的絮凝效果。     

旋转周期为曲柄二整周的平面双曲柄四杆机构

Grashof Neutral机构存在切换点(Change point)位置。通常认为机构在其切换点位置具有运动不确定性,其输入输出角速度比为0/0型不定式。根据运动连续性原理和洛毕达极限法则,首次导出了确定此类机构切换点(Change point)角速度比的解析公式。并通过机构运动分析、仿真,以及机构原型的制作和实验,证明:GrashofNeutral机构旋转通过切换点(Change point)时的运动是完全确定的,具其运动周期为驱动曲柄旋转二整周。特别是,当机构相对杆长差取很小值时,将输出有反向自锁特征和近似长停歇期的间歇运动,具有工业实用价值。