全文获取类型
收费全文 | 10936篇 |
免费 | 416篇 |
国内免费 | 147篇 |
专业分类
财政金融 | 1056篇 |
工业经济 | 503篇 |
计划管理 | 1747篇 |
经济学 | 1725篇 |
综合类 | 932篇 |
运输经济 | 71篇 |
旅游经济 | 98篇 |
贸易经济 | 967篇 |
农业经济 | 579篇 |
经济概况 | 1268篇 |
水利工程 | 2539篇 |
邮电经济 | 14篇 |
出版年
2024年 | 19篇 |
2023年 | 115篇 |
2022年 | 240篇 |
2021年 | 366篇 |
2020年 | 314篇 |
2019年 | 215篇 |
2018年 | 164篇 |
2017年 | 273篇 |
2016年 | 234篇 |
2015年 | 305篇 |
2014年 | 453篇 |
2013年 | 618篇 |
2012年 | 830篇 |
2011年 | 1146篇 |
2010年 | 1074篇 |
2009年 | 799篇 |
2008年 | 810篇 |
2007年 | 764篇 |
2006年 | 811篇 |
2005年 | 684篇 |
2004年 | 239篇 |
2003年 | 208篇 |
2002年 | 165篇 |
2001年 | 171篇 |
2000年 | 86篇 |
1999年 | 96篇 |
1998年 | 57篇 |
1997年 | 41篇 |
1996年 | 47篇 |
1995年 | 39篇 |
1994年 | 25篇 |
1993年 | 19篇 |
1992年 | 13篇 |
1991年 | 9篇 |
1990年 | 2篇 |
1989年 | 6篇 |
1988年 | 6篇 |
1987年 | 2篇 |
1984年 | 8篇 |
1983年 | 3篇 |
1982年 | 1篇 |
1981年 | 3篇 |
1980年 | 2篇 |
1977年 | 1篇 |
1976年 | 3篇 |
1973年 | 3篇 |
1972年 | 2篇 |
1971年 | 3篇 |
1970年 | 2篇 |
1969年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 8 毫秒
1.
2.
长三角区域行政合作构想 总被引:1,自引:0,他引:1
目前,长三角区域行政合作的发展陷入一系列困境,但是泛珠三角区域行政合作却取得很大成功。借鉴其成功的经验与启示,本文提出坚持共享区域合作成果,制定区域合作规范,建立区域合作机制,成立区域合作机构,重新规划区域行政布局等构想来促进长三角区域行政合作。 相似文献
3.
Spectral slope (S), describing the exponential decrease of the absorption spectrum over a given wavelength range, is an important parameter in the study of of chromophoric dissolved organic matter (CDOM) dynamics, and also an essential input parameter in remote sensing models. Furthermore, S is often used as a proxy for CDOM composition, including the ratio of fulvic to humic acids and molecular weight. The relative broad range in S values reported in the literature can be explained by the different spectral ranges and fitting methods used. A single exponential model is used to fit the S values for 17 investigations involving 458 samples in Lake Taihu from January to October in 2004. The average S value was 15.18 ± 1.39 μm−1 for the range of 280–500 nm, which fell within the range reported in the literature. The frequency distribution of S value basically obeyed a normal distribution. Significant differences in S values between summer and other seasons showed that phytoplankton degradation was one of the important sources of CDOM in summer, whereas CDOM mainly came from the river input in other seasons. Furthermore, the estimated S value decreased with increasing wavelength range used in regression. The maximum and minimum values derived from the regression were 17.89 ± 1.25 μm−1 and 13.62 ± 2.11 μm−1 for the wavelength ranges of 280–380 nm and 400–500 nm, respectively, a decrease of 23.9%. S values significantly decreased with the increase of CDOM absorption coefficients. CDOM absorption coefficients could be more appropriately estimated from exponential model introducing the variation of S with absorption coefficients, making them useful for a remote sensing bio-optical model of Lake Taihu. DOC-specific absorption coefficient a*(λ) and the parameter M describing molecular size of the humic molecules could also be used as a proxy for the sources and types of CDOM. A general relationship was found between S and a*(λ), and M values. S increased with the decrease of DOC-specific absorption coefficient and the increase of M corresponding to the decrease of molecular weight. 相似文献
4.
Ultraviolet (UV) disinfection is becoming increasingly popular as an alternative disinfection technology to chlorination in recent years. In this study, we investigated the photoreactivation of Escherichia coli following medium-pressure (MP) UV disinfection of synthetic water by a bench-scale collimated beam apparatus. The UV doses ranged from 1.6 -19.7 mWs/cm2 and photoreactivation was investigated for 6 hours under fluorescent light. In addition, chloramination was applied after UV disinfection to investigate its ability to control photoreactivation. It was found that photoreactivation occurred for all UV doses tested and the increase in bacteria numbers ranged from 0.04 to 1.35 log10. However, the degree of photoreactivation decreased with increased UV doses. Chloramination experiments revealed that the addition of 0.5 mg/l of monochloramine resulted in suppression of photoreactivation for 1 hour only. An increased monochloramine dose of 1 mg/l was found to prevent photoreactivation for the entire duration of the experiment. The results of this study have shown that photoreactivation occurs even after MP UV disinfection, although it is of a lesser extent at higher UV doses. This study has also established that secondary chloramination can effectively suppress and eliminate photoreactivation with a chloramine dose of 1 mg/l. 相似文献
5.
We apply a discrete choice approach to model the empirical behaviour of the Federal Reserve in changing the federal funds target rate, the benchmark of short‐term market interest rates in the US. Our methods allow the explanatory variables to be nonstationary as well as stationary. This feature is particularly useful in the present application as many economic fundamentals that are monitored by the Fed and are believed to affect decisions to adjust interest rate targets display some nonstationarity over time. The chosen model successfully predicts the majority of the target rate changes during the time period considered (1994–2001) and helps to explain strings of similar intervention decisions by the Fed. Based on the model‐implied optimal interest rate, our findings suggest that there is a lag in the Fed's reaction to economic shocks during this period. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
6.
民间金融与地方经济发展——温州融资模式的启示 总被引:4,自引:0,他引:4
由于我国现有金融体制的不足,无法满足私营中小企业和个体经济的融资需求,民间金融有其产生和存在的必然性和合理性。从温州发达的民间金融对其经济发展的作用和我国许多落后地区与温州改革前经济落后状况的雷同来看,我国现阶段应尽快建立健全民间金融制度和体系,以促进国民经济的快速发展。构建民间金融制度可分两步:首先承认民间借贷和各种会的合法地位,然后通过发展民营中小银行逐步取代它们。 相似文献
7.
信息技术的发展和应用使得信息技术专业人员角色压力问题日益突出,并对其心理、生理和行为都产生了不良的影响。本文采用实证研究方法,分析了授权与沟通这两个组织环境因素对信息技术员工角色压力的影响,并根据研究结论得出了一些缓解角色压力的管理启示。 相似文献
8.
9.
非线性地基上桩结构物空间分析 总被引:1,自引:0,他引:1
本文提出了桩结构物-非线性地基空间相互作用分析的迭代法和非线性有限元法。其中,桩基分析用p-y曲线法。结合实际结构物进行了大量的计算及比较分析,成果是令人满意的,可以付诸应用。 相似文献
10.
我国现有地租形式-批租制与年租制的单调和局限性,致使无法运用它们完成对全部城镇国有土地的地租征缴。理论界对现有地租形式进行中庸式的综合,创造出两种新的地租形式-短租制与长约年租制,但仍有种种不足,本文对长约年租制进行了改进,并结合土地金融手段,设计了一种全新的地租形式-按揭批租制。 相似文献