期刊文献+
共找到3篇文章
< 1 >
每页显示 20 50 100
我国回流农民工研究综述 被引量:12
1
作者 齐小兵 《西部论坛》 2013年第2期28-34,共7页
受农民工的代际更替、产业政策、户籍制度等因素的影响,中国农民工回流逐渐成为一个新的发展趋势;同时,受限于二元分割的城乡制度,中国农民工反向迁移的比率或者说潜在比率要远远高于国外。目前,关于中国农民工回流的研究主要集中于回... 受农民工的代际更替、产业政策、户籍制度等因素的影响,中国农民工回流逐渐成为一个新的发展趋势;同时,受限于二元分割的城乡制度,中国农民工反向迁移的比率或者说潜在比率要远远高于国外。目前,关于中国农民工回流的研究主要集中于回流规模、回流原因、回流农民工群体的特征以及回流的社会影响等方面。总体上看,中国农民工回流研究仍处于起步阶段,而且过多地侧重于宏观层次的回流原因分析与回流影响的考察,而缺少对回流农民工个人层面的具体分析,还需要进行更为深入、细致的调研分析与经验考察。 展开更多
关键词 回流农民工 劳动力迁移 推拉理论 主动回流 被动回流 社会资本 城乡二元结构 户籍制度 土地制度 农村发展
在线阅读 下载PDF
《农民工的终结》:农民工发展的趋势和方向 被引量:2
2
作者 雷洪 刘丹 《华中科技大学学报(社会科学版)》 CSSCI 北大核心 2018年第3期138-140,共3页
20世纪80年代社会转型与中国的城乡二元经济体制的共同作用,带来了中国农村劳动力在城乡之间的大规模流动。农业转移人口的群体规模大、流动性强、涉及面广,对城市和农村,以及农民工个人的发展都带来深远的影响。
关键词 主动回流 劳动力群体 农民工 城镇化 农民工回流
在线阅读 下载PDF
Dynamic simulation of drum level sloshing of heat recovery steam generator
3
作者 曹小玲 皮正仁 +2 位作者 蒋绍坚 杨卫宏 B.Wlodzimerz 《Journal of Central South University》 SCIE EI CAS 2013年第2期413-423,共11页
Drum level sloshing is the latest discovery in the application of heat recovery steam generator (HRSG) in combined cycle, and shows certain negative influence on drum level controlling. In order to improve drum level ... Drum level sloshing is the latest discovery in the application of heat recovery steam generator (HRSG) in combined cycle, and shows certain negative influence on drum level controlling. In order to improve drum level controlling, influence factors on the drum level sloshing were investigated. Firstly, drum sub-modules were developed using the method of modularization modeling, and then the model of drum level sloshing was set up as well. Experiments were carried out on the experimental rig, and the model was validated using the obtained experimental results. Dynamic simulation was made based on the model to get a 3-D graph of drum level sloshing, which shows a vivid procedure of drum level sloshing. The effect of feed-water flow rate, main-steam flow rate and heating quantity on the drum level sloshing was analyzed. The simulation results indicate that the signals with frequency higher than 0.05 Hz are that of drum level sloshing, the signals with frequency of 0.0-0.05 Hz are that of drum level trendy and "false water level", and variation of the feed-water flow rates, main-steam flow rates and heating quantities can change the frequency of drum level sloshing, i.e., the frequency of sloshing increases with the increase of feed-water flow rate, or the decrease of the main-steam flow rate and the heating quantity. This research work is fundamental to improve signal-to-noise ratio of drum level signal and precise controlling of drum level. 展开更多
关键词 combined cycle heat recovery steam generator false level drum level sloshing model modularization modeling
在线阅读 下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部