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1.
In horticultural markets, trade barriers often apply to the processed products whereas domestic support applies to farm-produced raw commodities. Here we assess the effects of such trade barriers and domestic support by simulating the effects of policy reform on global processing tomato markets, which are faced with modest processed product tariffs and high domestic support in the European Union (EU). Both protection and EU subsidy drive down world welfare, but we find that reducing import tariffs for tomato products would yield greater effects on markets and larger welfare impacts outside Europe than would reductions in EU domestic support.  相似文献   
2.
在湖南省长沙市芙蓉综合楼基坑支护工程中,针对人工填土、淤泥质粘土等工程性能差的坑壁土体,采用排桩式土钉墙技术进行支护,经济效益显著。  相似文献   
3.
位于扬子地台北缘的武当推覆体是南秦岭造山带的重要组成部分,它经历了漫长的构造演化历程。该区的层固性结构和加里东—晋宁期的伸展滑脱作用造成了武当群构造堆垛岩系的形成,华北板块和扬子板块在印支运动期间的会聚、碰撞造山作用使武当巨型推覆体逐渐形成,至喜山运动时期完全定位。本文分析了这些构造运动所产生的变形效应及构造变形的复合关系,揭示了本区变形环境由低温高压或高应变速率环境向中温低压及低温低压过渡的特征,阐述了武当推覆体的形成、武当群岩系的变形效应与动力作用方式、变形岩石的边界条件、变形岩石的结构构造以及力学性质的关系,把武当群的形成、武当推覆体的演化分为三期五个阶段,其构造变形的主要动力来源为沿大陆边坡的重力滑动和陆-陆碰撞的挤压作用,其应力作用方式为由上述动力所产生的近南北向伸展和近南北向挤压两大地应力场的转化。  相似文献   
4.
对一种已经通过试验研究的钢管混凝土结构的新型节点进行数值分析。这种节点将钢管混凝土柱的钢管在节点区间断,在节点区设置芯钢管,使梁中的纵筋在节点中直通、梁与节点区混凝土成为一体可靠的传递梁中的弯矩、剪力及轴力。本文利用数值分析弥补模型试验数量少的缺陷。选择不同芯钢管壁厚的节点模型进行非线性有限元分析,得出芯钢管壁厚对节点承载力的影响规律。分析结果表明芯钢管壁厚是影响节点承载力的主要因素之一。  相似文献   
5.
根据功能原理建立能量补充方程,并利用静力平衡方程,求解一次拉压超静定问题。该方法同时可用于扭转、弯曲等一次超静定问题的求解。  相似文献   
6.
Schlichtman and Patch suggest that there is an elephant sitting in the academic corner: while urbanists often use ‘gentrification’ as a pejorative term in formal and informal academic conversation, many urbanists are gentrifiers themselves. Even though urbanists have this firsthand experience with the process, this familiarity makes little impact on scholarly debate. There is, Schlichtman and Patch argue, an artificial distance in accounts of gentrification because researchers have not adequately examined their own relationship to the process. Utilizing a simple diagnostic tool that includes ten common aspects of gentrification, they compose two autoethnographic memoirs to begin this dialogue.  相似文献   
7.
孙全海 《价值工程》2021,40(2):114-117
山区公路路基往往是在斜坡上填筑的,这种填筑形式更易于发生变形破坏,故本文以某斜坡路基为研究对象,研究斜坡路基地基变形机理,并用强度折减法分析该斜坡路基的稳定性。结果表明:①地基形变的总体趋势以沉降变形为主,随填筑高度的增加,水平位移逐渐趋于均匀,并表现为侧向外鼓,沉降最大值集中在与填筑体中心相交的区域。②路基中心的最终沉降位移相较于坡脚的2倍;路基整体有向斜坡下滑移的趋势;短坡脚的水平位移发展最快。③斜坡路基随填筑高度的增加,从深层滑动发展为浅层滑动,滑体集中于长坡脚。④随填筑高度的增加,安全系数逐渐降低。  相似文献   
8.
Gentrification in China is intertwined with urban redevelopment, which causes the large‐scale displacement of rural–urban migrants from ‘villages in the city’ (ViCs). Because of the informality of ViCs, migrant renters have very insecure tenancy and during redevelopment they are treated as a negligible (‘invisible’) social group. As they are very difficult to locate after displacement, they are also literally invisible to researchers. To make the invisible visible, this study traced a sample of displaced migrants from Huangbeiling village in Shenzhen. The focus was on the displacement process and on identifying the consequences for the displaced. We found various forms of displacement during the redevelopment process. Nearby ViCs were prioritized by displaced migrants to minimize as much utility loss as possible. However, they generally suffer from decreased proximity, increased living costs, and the loss of social networks and job opportunities. Remarkably, some choose to return to the gentrifying village, enduring displacement in situ caused by increasing rents, drastic physical neighbourhood changes and declining liveability, in exchange for retaining their original social and economic networks. Large‐scale urban redevelopment is causing the rapid shrinkage of informal housing. Recognizing and addressing the housing needs of this impoverished social group is a matter of urgency.  相似文献   
9.
Abstract:

Through a comprehensive review of the progressive institutional change (PIC) literature, I first discuss four possible trajectories of PIC by considering the forces of societal reaction that might frame the path, as well as the scale and scope of the changes. Thus, I pose four questions that need to be asked when related policies are formulated for PIC. To illustrate this method, I scrutinize the evidence from the construction of a socialist market economy by the Chinese government since the 1980s and argue that related policies have successfully promoted PIC from three dimensions: (1) curbing potential conflicts with power groups; (2) promoting a sense of awareness among stakeholders; and (3) minimizing disturbances to the community. Actually, the related changes demonstrate a dynamic “displacement process” for PICs. Despite the success of this sociosystem, it is found that the sustaining of PIC which requires policy factors that enhance instrumental efficiency in the Chinese context will serve as a challenge to the Chinese government ahead.  相似文献   
10.
本文为了阐述钢结构变形的主要种类并介绍U型槽钢构建焊缝变形的火焰矫正施工方法,在多年工作经验的基础上还结合了同行的相关资料,在实际的工作中作出了有益的尝试。  相似文献   
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