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压浆处治技术,是针对砼路面在使用过程内出现的板块脱空危害而提出的修复板底基层密实,确保板底均匀支撑的技术措施,其作用为:通过压浆处治,可以充实板底脱空,恢复密实,改善面板的支撑状况,使砼板的受力状态符合设计原理,避免砼路面板过早损坏。通过对板底脱空的压浆处治,由于压浆材料本身稳定性好,强度大,加上浆体的流动性能好,在压力作用下,有较强的渗透力,因而能够改善基层和路基的密实度和水稳定性,从而增加基层的稳定性,增强路面的使用寿命。为此,我们正在积极探索一些切实可行的修补方法。 相似文献
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二甲醚的市场概况及发展前景 总被引:1,自引:0,他引:1
本文介绍了二甲醚的用途、市场前景、生产情况及存在的问题。指出二甲醚是一种用途广泛、市场前景看好的化工产品,我国应有计划上马DME装置,加快开发DME下游产品。 相似文献
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Dynamic Benchmarking of Mass Transit Systems in the United States Using Data Envelopment Analysis and the Malmquist Productivity Index 下载免费PDF全文
For more than five decades, the federal, state, and local governments have subsidized mass transit systems through sales, gasoline, and property taxes with an expectation that it would improve mobility to low‐income citizens, reduce carbon footprints and traffic congestion, and facilitate regional economic growth. However, in times of financial crisis and chronic government budget deficits, the inefficient use of a mass transit system can increase public outcry over the wasteful spending of government funds and taxpayers’ monies. To find ways to utilize mass transit systems more efficiently across the United States, this paper aimed to identify the benchmark transit practices that every mass transit system can emulate and then continuously improve its performance. To achieve these goals, this paper analyzed the multiple years of past performances of 262 mass transit agencies in the United States using data envelopment analysis and the Malmquist productivity index and then provided practical guidelines for enhancing mass transit efficiency. 相似文献
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本文基于协整分析技术,分析技术进步对劳动要素的析出是短期的波动,二者在长期中不存在稳定的替代关系。并且,与很多呼吁放弃政府调控工资的结论不同,本文指出,可以通过工资水平这一桥梁工具来调控要素价格比率,以此实现兼顾促进技术进步的长远利益和避免短期就业的剧烈波动的目标,从而在推进技术进步的条件下发挥我国的劳动要素禀赋优势。 相似文献