期刊文献+
共找到2篇文章
< 1 >
每页显示 20 50 100
沥青路面龟网裂成因及防治
1
作者 宁长河 《活力》 2005年第9期140-140,共1页
由于公路自身特点,各地区气候、地质、地形、水文状况的差异,以及交通量和超限运输车辆的逐年增加,致使公路路面病害频繁,严重影响了交通运输。面对这种形势,如何保证公路畅通,实现公路的“畅、洁、绿、美”,为社会提供一个良好... 由于公路自身特点,各地区气候、地质、地形、水文状况的差异,以及交通量和超限运输车辆的逐年增加,致使公路路面病害频繁,严重影响了交通运输。面对这种形势,如何保证公路畅通,实现公路的“畅、洁、绿、美”,为社会提供一个良好的公路运输环境,成为我们面前的重要课题。 展开更多
关键词 沥青路面 龟网裂病害 公路建设 防治措施 经济对比度
下载PDF
Evolution Rules of Urban-rural Development and Inspiration for China's Agriculture
2
作者 Liu Ziqiang Li Jing +1 位作者 Lu Qi Liu Yansui 《Chinese Journal of Population,Resources and Environment》 2009年第3期48-54,共7页
Based on urban-rural contrast coefficient,this article designs the agriculture relative development index(ARDI) as indicators measuring the intensity of urban-rural dual structure which is comparable among the countri... Based on urban-rural contrast coefficient,this article designs the agriculture relative development index(ARDI) as indicators measuring the intensity of urban-rural dual structure which is comparable among the countries of the world.This article calculates ARDI of 40 countries from 1980 to 2004.The result shows that ARDI in the developed countries and most of the middle-income countries are rising and yet there are declines in most of the low-income countries.The result also showed that most countries' ARDI will see a decline at the earlier stage of industrialization,so their dual economic structure will also aggravate and urban-rural gap will widen.With the economic development,the tendency will change and ARDI presents a U-shape change overall.The turning point is when a country becomes a middle-income one. 展开更多
关键词 dual economic structure the agriculture relative index urban-rural relation
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部