考虑输电投资效率的长期节点电价模型

该文对以电力市场长期效率为优化目标的长期节点电价模型进行了研究,通过对长期最优潮流模型的分析,可以对各个时段的发电功率、用电功率和该投资周期内的电网容量实现优化,并在此基础上计算输电线路的阻塞租金和各节点的长期节点电价.研究结果表明,输电线路的最优容量取决于其阻塞租金,而以长期效率为目标的节点电价能提供正确的价格信号....     

热电联产燃气余热锅炉热效率分析

在环保和节能日益受到重视的背景下,研究影响燃气余热锅炉热效率和环保的工况点具有重要意义.文章以2台热电联产燃气余热锅炉为研究对象,在10种不同的工况下,研究锅炉热效率和烟气排放情况,分析了运行工况、热效率和烟气排放之间的关系,为提高燃气余热锅炉热效率和降低尾部烟气排放提供了指导.     

四相平板式TFPM正弦波驱动研究

针对四相平板式TFPM在运行时存在转矩脉动、转换效率低的问题,根据电机本身的反电动势波形,提出一种新型正弦脉宽调制(SPWM)控制方法.在分析四相平板式TFPM工作原理和驱动方式的基础上,采用SPWM的控制方法并以135°的导电模式驱动电机.实验结果表明,SPWM控制方法能提高电机的转换效率,在低转速时,转换效率提高8％;在额定转速下,转换效率提高11％,并能减小电机的转矩脉动.     

影响脱硫石膏旋流器性能的关键指标

石膏旋流器在湿法脱硫的脱水环节起着重要的作用,其性能还会影响到真空皮带脱水机的正常工作。在对石膏旋流器进行研究时,既要注重能耗、分离效率、分离粒度等指标,也不能忽略底流固体质量分数、分级精度上的要求。分析了影响石膏旋流器主要指标的因素,强调了固体质量分数和分级精度的重要性。根据实验数据,给出了较为合理的溢流、底流口径比及入口压力的取值范围,可为石膏旋流器的进一步优化提供参考。     

微弧等离子喷枪电热特性分析

等离子喷枪的电弧伏安特性和热效率等电热特性是影响等离子喷涂质量的重要因素,文中根据自行研制的微弧等离喷涂系统,开展等离子喷枪的电热特性研究,分析了不同进气方式下的电弧伏安特性以及微弧等离子喷枪的热效率．结果表明,等离子喷枪在不同进气方式下均呈现下降的伏安特性,在相同电流和气体流量条件下,直流和切向混合进气方式下喷枪的电...     

Strength enhancement of autocompleting medium and high carbon steels friction welded joints

An autocompleting friction welding method, which was developed by the authors, is to weld with using a rotating insert piece set between fixed workpieces. The conditions to enhance the strength of the welded joint in an autocompleting friction welding method which involves a rotating insert between the fixed workpieces were determined. The weld faying surface of the fixed specimen had a 10 mm diameter. When MCS joint was made at an insert thickness of 4 mm through a friction pressure of 36 MPa, it did not achieve 100% joint efficiency because the weld interfaces were not completely joined. MCS joint had 100% joint efficiency and fractured on the MCS base metal although the crack was generated at the weld interface, when that was made at an inner groove diameter of 11 mm with the bottom of the grooves for the insert piece (groove bottom thickness) of 0.9 mm or more through a friction pressure of 90 MPa. To obtain a joint with no cracks, MCS joint was made with an inner groove diameter of 12 mm at a friction pressure of 90 MPa. When the groove bottom thickness was 0.75 mm, MCS joint had 100% joint efficiency and the MCS base metal fracture with no crack at the weld interface. When HCS joint was made with an inner groove diameter of 11 mm at friction pressures of 90 and 150 MPa, it did not achieve 100% joint efficiency because the weld interfaces were not joined completely. The weld interfaces of HCS joint at a friction pressure of 120 MPa were completely joined although it did not achieve 100% joint efficiency. To improve the joint efficiency, HCS joint was made with an insert thickness of 5 mm, a groove bottom thickness of 0.64 mm, and an inner groove diameter of 12 mm with a friction pressure of 120 MPa. HCS joint had 100% joint efficiency and fractured on the HCS base metal with no crack at the weld interface.     

油松籽油酸洗缓蚀剂的合成与应用

以油松籽油、二乙烯三胺、氯化苄为原料,合成了咪唑啉季铵盐缓蚀剂Y-1,用失重法、极化曲线法评价了Y-1及其与硫脲复配后的新型缓蚀剂的缓蚀性能.结果表明:缓蚀剂Y-1在盐酸体系中对A20钢有很好的缓蚀效果,由Y-1和硫脲复配的新型缓蚀剂在柠檬酸体系中对A20钢的缓蚀效率在99.65％以上,并且二者都具有很好的热稳定性;缓...     

提高密炼机生产效率的控制程序优化

通过对密炼机工作原理的分析,将炼胶的各步序通过控制程序适当缩短时间,使单车炼胶时间缩短40 s。同时,通过修改程序,解决了一系列保障胶料工艺质量方面的问题。还介绍了上辅机自动称量、双螺杆调速、胶片冷却联动线等设备的一些控制改进方法。通过这些改进措施,有效地提高了生产率,节约了能源。     

Effects of dietary n−3/n−6 ratio on lipid metabolism of gilthead seabream (Sparus aurata)

The current study was conducted to evaluate the effects of various dietary n?3/n?6 ratio on growth and lipid metabolism in gilthead seabream (Sparus aurata) juveniles. The fish were fed ad libitum on three isoproteic (52%), isolipidic (14%), and isoenergetic diets (21 MJ/kg), formulated to contain three different n?3/n?6 ratios: a high (3.8), medium (2.5), or low (0.9) ratio. Fish grew from 9.5 ± 0.1 g to 54.2 ± 0.7 g in 12 weeks. Growth rate (2.2% BW/day), voluntary feed intake (2.4 ± 0.1% BM/day), feed conversion ratio (1.38 ± 0.05), and net protein utilization (27.5 ± 1.0%) did not vary among treatments. In contrast, body lipid content and lipid deposition efficiency were significantly reduced in fish fed low n?3/n?6 ratio. Fish fed the highest n?3/n?6 ratio showed the lowest hepatic glucose‐6‐phosphate dehydrogenase (G6PD) activity (p = 0.02). The n?3/n?6 ratio decreased, while DHA/eicosapentaenoic acid (EPA) ratio increased significantly with decreasing dietary n?3/n?6 content. Among n?3 PUFA, the DHA and, particularly, the docosapentaenoic acid (DPA) showed the highest deposition rate both in muscle and liver. The lower deposition rate (<1) of linoleic acid (LA) and linolenic acid (LNA) suggests that a reduction in dietary n?3/n?6 ratio may stimulate their transport to the intermediary metabolism for energy production.     

VBA无损检测数据库管理系统的开发及应用

开发应用VBA无损检测数据库管理系统,可解决无损检测结果统计、报告编制等工作需要人员多、花费时间长、易错易漏、滞后等问题,极大提高无损检测工作的准确性和工作效率,尤其是与互联网结合起来可实现远程控制管理,是现代无损检测企业提高管理效率的先进方法。