首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   26518篇
  免费   1424篇
  国内免费   797篇
财政金融   1257篇
工业经济   1135篇
计划管理   5341篇
经济学   3365篇
综合类   2110篇
运输经济   351篇
旅游经济   714篇
贸易经济   2701篇
农业经济   1933篇
经济概况   2338篇
水利工程   7494篇
  2024年   129篇
  2023年   397篇
  2022年   523篇
  2021年   702篇
  2020年   894篇
  2019年   755篇
  2018年   759篇
  2017年   970篇
  2016年   982篇
  2015年   991篇
  2014年   1960篇
  2013年   2262篇
  2012年   2150篇
  2011年   2589篇
  2010年   1822篇
  2009年   1654篇
  2008年   1773篇
  2007年   1610篇
  2006年   1353篇
  2005年   1104篇
  2004年   801篇
  2003年   558篇
  2002年   387篇
  2001年   321篇
  2000年   269篇
  1999年   172篇
  1998年   157篇
  1997年   121篇
  1996年   112篇
  1995年   100篇
  1994年   92篇
  1993年   59篇
  1992年   61篇
  1991年   34篇
  1990年   13篇
  1989年   21篇
  1988年   7篇
  1987年   10篇
  1986年   9篇
  1985年   13篇
  1984年   15篇
  1983年   15篇
  1982年   8篇
  1981年   1篇
  1980年   2篇
  1979年   2篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
21.
The paper focuses on the long run relationships between wages, prices and labour productivity in the Polish economy by applying recent developments in the field of multivariate cointegration analysis. We followed modeling strategy which is suggested by Greenslade et al. (1999) and present all stages of the analysis which leads to the fully economically identified system of equations representing long run relationships. The investigation is based on the quarterly data from 1992.1 to 1999.2 which covers the period of transition of the Polish economy from the centrally planned system towards the market one. Basing on the empirical results we can argue that wages (costs) were one of the main forces driving inflation in Poland during that period. Also labor productivity proved to be stimulated by the increase of the real wages. On the other hand the hypothesis concerning the relationship between wages and unemployment was rejected by the data.  相似文献   
22.
战后,在实现经济恢复和高速发展过程中,日本政府高度重视财政政策的宏观调控作用,在运用财政政策调节经济方面开辟了一条符合本国国情、突出本国特点的路子.对日本战后积极财政政策进行分析和评价,对我国经济发展具有重要的参考借鉴意义。  相似文献   
23.
张林成 《人民长江》2001,32(12):9-11
安徽省境内765km的长江干堤,由于均是在原来旧堤的基础上经逐年加高培厚的,修筑时均未按设计要求施工,致使堤身密实度不够,新老堤土之间结合不牢,在汛期高水位时易产生渗漏。20世纪70年代以来,安徽省高度重视对长江干堤渗漏隐患的处理,经过长期的实践,逐渐摸索出一套行之有效的除险加固方法,如锥探灌浆、灭杀白蚁、冲抓套吉、垂直铺塑防渗、粘土铺盖及压渗盖重等处理措施。使长江干堤的渗漏隐患得以基本消除,其具体作法可供类似工程借鉴。  相似文献   
24.
西北江三角洲来水来沙的非线性分形特征   总被引:3,自引:0,他引:3  
根据西、北江干流高要、石角及西北江三角洲网河区顶点马口、三水四个水文站的流量和含沙量资料 ,应用非线性分形原理的R S方法 ,计算西北江干流及西北江网河区顶点四个水文站的流量、含沙量的赫斯特数H和分形维数D ;探讨西、北江干流来水来沙的分形特征及西北江三角洲的分水分沙规律。结果表明 ,流量的分维数略大于含沙量的分维数 ,三水站流量及含沙量的分维数与其上游的石角站流量、含沙量的分维数相差较大 ,与思贤的分水分沙造成西北江的水沙交换有关  相似文献   
25.
大黑汀大坝安全监测应用分析软件的开发与应用   总被引:1,自引:1,他引:0  
在大坝安全监测工作中,结合实际工程情况和工作需要,利用Visual Basic 6.0编程语言,开发出一套实用的安全监测应用分析软件,解决了数据共享、监测成果检查、自动化与人工测值比较、各种数据报表输出、历史数据提取、过程线分布图绘制等许多实际应用问题,极大地提高了工作效率,实现了大坝安全监测自动化。  相似文献   
26.
基于聚类分析电信运营企业仓库布局优化研究   总被引:1,自引:0,他引:1  
祝丽  汝宜红  罗平 《物流技术》2007,26(8):106-109
以某电信运营企业为例,在现场调研的基础上,分析了企业仓库布局的主要问题,应用聚类分析方法,提出了仓库布局优化方案,并进行了方案的综合评价.  相似文献   
27.
Most decision making research in management accounting remains focused on cost information in a production context. Little is known on the relevance of customer profifitability analysis (CuPA) reports, which more accurately reflect revenue and marketing support variations acrosscustomers, for marketing decisions. This study uses an experimental design to examine the impact of such reports on resource allocation decisions (that affect the firm's profits) in marketing environments varying in complexity. The main result of the experiment suggests that the value of CuPA reports depends on the complexity of the marketing setting. Only in a highly complex marketing setting do they enhance resource allocation decisions and resultant firm profitability. Conversely, in the simple marketing environment, decision makers can combine their traditional volume-based cost data with other available types of feedback to perform as well as under a more accurate CuPA report. These findings on complexity contrast with those of a prior study in a production context ( Gupta and King, 1997 ). It is argued that improvements in the current research design, in the form of regularly updated profitability reports and concerning accuracy, increase the relevance of CuPA reports in a complex marketing setting.  相似文献   
28.
Integrated watershed management is required to ensure the reasonable use of resources and reconcile interactions among natural and human systems. In the present study, an interval fuzzy multiobjective programming (IFMOP) method was used to solve an integrated watershed management problem. Based on system analysis, an IFMOP model suitable for a lake watershed system {IFMOPLWS} was developed and applied to the Lake Qionghai watershed in China. Scenario analysis and an interactive approach were used in the solution process. In this manner, various system components were incorporated into one framework for holistic consideration and optimization. Integrality and uncertainty, as well as the multiobjective and dynamic characteristics of the watershed system, were well addressed. Using two scenarios, two planning schemes were generated. Agriculture, tourism, macroeconomics, cropland use, water supply, forest coverage, soil erosion, and water pollution were fully interpreted and compared to identify a preferable planning alternative for local agencies. This study showed that the IFMOPLWS is a powerful tool for integrated watershed management planning and can provide a solid base for sustainable watershed management.  相似文献   
29.
混凝土面板堆石坝是引子渡水电站的主要水工建筑物,在大坝坝体填筑及混凝土面板的施工过程中,通过室内及现场试验确定了质量控制参数,并采取了必要的质量控制措施,从而保证了工程质量。本文主要对质量控制情况及检测成果作简要介绍。  相似文献   
30.
Coupling GIS with Hydrologic and Hydraulic Flood Modelling   总被引:6,自引:1,他引:5  
Geographic Information Systems (GIS) have been recognised as a powerful means to integrate and analyse data from various sources in the context of comprehensive floodplain management. As part of this comprehensive approach to floodplain management, it is very important to be able to predict the consequences of different scenarios in terms of flooded areas and associated risk. Hydrologic and hydraulic modelling plays a crucial role and there is much to gain in incorporating these modelling capabilities in GIS. This is still a rather complex task and research is being done on the full integration of these models. Interfacing between these models and GIS may be a very efficient way of overcoming the difficulties and getting very good results in terms of engineering practice. This paper presents results based on the use of Intergraph GIS coupled with Idrisi GIS. Using these two systems substantially increased the flexibility of using GIS as a tool for flood studies. A lumped (XSRAIN) and a distributed (OMEGA) hydrologic models were used to simulate flood hydrographs. The well known HEC-2 Hydraulic model was used to compute flooded areas. These models were applied in the Livramento catchment with very good results. The computation of flooded areas for different flood scenarios, and its representation in GIS, can be used in the assessment of affected property and associated damages. This is a very useful GIS-based approach to floodplain management.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号