全文获取类型
收费全文 | 151147篇 |
免费 | 3786篇 |
国内免费 | 40篇 |
专业分类
财政金融 | 25536篇 |
工业经济 | 11565篇 |
计划管理 | 21731篇 |
经济学 | 29281篇 |
综合类 | 1544篇 |
运输经济 | 973篇 |
旅游经济 | 2504篇 |
贸易经济 | 23561篇 |
农业经济 | 6187篇 |
经济概况 | 16880篇 |
水利工程 | 14953篇 |
信息产业经济 | 7篇 |
邮电经济 | 251篇 |
出版年
2021年 | 1089篇 |
2020年 | 1824篇 |
2019年 | 2646篇 |
2018年 | 2677篇 |
2017年 | 2752篇 |
2016年 | 3090篇 |
2015年 | 2392篇 |
2014年 | 3826篇 |
2013年 | 16392篇 |
2012年 | 4739篇 |
2011年 | 4515篇 |
2010年 | 4044篇 |
2009年 | 4690篇 |
2008年 | 4254篇 |
2007年 | 3628篇 |
2006年 | 3977篇 |
2005年 | 3898篇 |
2004年 | 3459篇 |
2003年 | 3102篇 |
2002年 | 3108篇 |
2001年 | 2927篇 |
2000年 | 2750篇 |
1999年 | 2664篇 |
1998年 | 2530篇 |
1997年 | 2614篇 |
1996年 | 2445篇 |
1995年 | 2241篇 |
1994年 | 2243篇 |
1993年 | 2221篇 |
1992年 | 2303篇 |
1991年 | 2159篇 |
1990年 | 2027篇 |
1989年 | 1906篇 |
1988年 | 1801篇 |
1987年 | 1809篇 |
1986年 | 1825篇 |
1985年 | 2647篇 |
1984年 | 2535篇 |
1983年 | 2340篇 |
1982年 | 2204篇 |
1981年 | 2140篇 |
1980年 | 2151篇 |
1979年 | 2076篇 |
1978年 | 1870篇 |
1977年 | 1817篇 |
1976年 | 1640篇 |
1975年 | 1479篇 |
1974年 | 1400篇 |
1973年 | 1404篇 |
1972年 | 1099篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
Using data for a sample of Malaysian stocks that are traded in both Malaysia and Singapore, we show that the turnover rate (trading volume relative to shares held) is significantly higher in the foreign market than in the domestic market. We also find that ownership of cross–listed shares by foreign investors is not motivated by diversification benefits. Instead, we find that the proportion of a firm's shares held in Singapore is directly related to the firm's level of systematic risk. 相似文献
52.
L. Zhang Simon X. B. Zhao J. P. Tian 《International journal of urban and regional research》2003,27(4):912-937
This article focuses on the housing issues of rural migrants arising from urbanization, with particular reference to chengzhongcun, a topic with considerable impact on policymaking. An attempt is made to understand the underlying rationale of self‐help in housing and the important role of chengzhongcun in sheltering rural migrants in the context of China's rural‐urban dichotomy. As demonstrated in this study, chengzhongcun accommodate, with little in the way of government resources and assistance, millions of rural migrants because of their social accessibility and affordability. While not denying their social problems, we argue that chengzhongcun in fact act as an innovative and positive agent to promote urbanization in present day China by housing massive numbers of rural migrants and assimilating them into cities. Current government policies towards chengzhongcun have generated a wide range of interest conflicts and confrontations. The consequences of such conflicts show that the government policies were problematic and unworkable, as they violated basic market principles as well as citizen rights. Policy strategy towards the redevelopment of chengzhongcun must acknowledge their credibility in the Chinese road to urbanization and requires more thoughtful and prudent consideration of migrants' demands for affordable housing. 相似文献
53.
54.
An Imhoff tank was reconstructed into a 250 m3 UASB reactor in order to treat a malting plant wastewater. The UASB was inoculated with sludge from an anaerobic lagoon used for slaughterhouse wastewater treatment. After two months of operation the reactor achieved full load with an HRT of 17 h, a COD removal higher than 80% and a biogas production of 300 m3/day (77% average methane content), with an organic loading rate of 3.6 kgCOD/m3.d (0.24 kgCOD/kgVSS.d). A yield coefficient of 0.09 gVSS/gCODrem was found from a mass balance. The fat present in the inoculated sludge (48 mg/gSSV) did not affect the start up performance. Sludge from the inoculum with high content of fat (270 mg/gSSV), was separated by flotation in the first week of operation. The COD removal efficiency was scarcely influenced by the reactor operation temperature (17-25 degrees C). 相似文献
55.
Models that link ecological responses to hydrologic changes are important for assessing the effects of flow regulation on aquatic and riparian ecosystems. Based on the Recruitment Box Model, a graphical model used to prescribe environmental flows for cottonwood (Populus spp.) recruitment, we designed a simulation model to represent the influence of river flow dynamics on seedling recruitment of riparian pioneer woody plants. The model simulates the influence of temporal patterns of river stage on dispersal, germination, initial recruitment and over‐winter survival of first‐year seedlings of riparian pioneer shrubs and trees. We used the model to simulate seedling recruitment patterns for five species (Acer saccharinum, Betula nigra, Populus deltoides, Salix nigra and Salix exigua) on the Wisconsin River (Wisconsin, USA) under three flow scenarios: historic (1935–2002), simulated natural (1915–1975) and simulated regulated flows (1915–1975). Simulation results agreed well with field‐observed relative differences among years (1997–2000) in seedling densities for the five focal species. Simulated successful recruitment years were highly synchronous among species, but species differed in their sensitivity to flows at different times during the growing season, consistent with among‐species differences in seed dispersal timing. Comparison of simulated natural and regulated flows for 1915–1975 showed that flow regulation decreased monthly flow variability, increased late summer to winter baseflow and reduced the magnitude of spring peaks. Simulated recruitment and over‐winter survival of tree seedlings of all species was enhanced under the regulated flow scenario, likely due to increased summer baseflow and reductions in peak flood magnitude. Our analyses show the utility of extending the Recruitment Box Model to include multiple species of riparian shrubs and trees, and the effects of post‐colonization flows on their recruitment success. However, some key functional relationships between flow patterns and woody seedling demography (e.g. shear stress thresholds for seedling mortality) have not been adequately quantified and merit further study. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
56.
In the UK, 1950-75 was a lively period in the long-running debates between proponents of absorption and marginal costing. In the nexus of competing interests, management accountants advocated and defended rival costing systems with much vigour and passion. Expressed in the language of the times, these debates were 'battles' in the costing 'war'. We focus on these battles, analysing the various forces that operated upon the combatants, and locate them in the wider costing war. We conclude that no final resolution of the conflict was achieved in the twentieth century, nor is one likely in the foreseeable future. 相似文献
57.
Thomas S. Lowry John C. Bright Murray E. Close Christina A. Robb Paul A. White Stewart G. Cameron 《国际水资源开发杂志》2003,19(4):579-592
The primary objective of this project is to identify gaps, whether real or perceived, that hinder effective groundwater management in New Zealand. These gaps show as gaps in information, gaps in implementation, gaps in technological and management tools, and gaps in understanding of fundamental processes. The secondary objective is to propose a management strategy to close the identified gaps. Several methods are used to meet these objectives: surveys distributed to selected staff in each regional council; the review of various written reports; the analysis of land-use databases; and private consultation within each regional council. Results show that groundwater management in New Zealand is generally reactionary with the main gaps being in strategic planning and national guidelines. Most gaps appear to be predominantly information and implementation issues. In some cases there are gaps in the understanding of fundamental processes within an aquifer system, including the long-term effects of land-use on groundwater quality. An adaptive management approach is suggested as a means of closing these gaps. 相似文献
58.
59.
The paper examines the relationship between transitory terms‐of‐trade shocks and private saving. Using a model allowing for nonseparability between the consumption of tradables and nontradables, the paper estimates the intertemporal elasticity of substitution while accounting for the intratemporal elasticity of substitution between the consumption of tradables and nontradables. Empirical analysis of data for five industrial countries indicates that in response to transitory terms‐of‐trade shocks, intertemporal substitution of consumption and intratemporal substitution of consumption between tradables and nontradables both have large effects on private saving. 相似文献
60.
The American Psychological Association Task Force recommended that researchers always report and interpret effect sizes for quantitative data. However, no such recommendation was made for qualitative data. Thus, the first objective of the present paper is to provide a rationale for reporting and interpreting effect sizes in qualitative research. Arguments are presented that effect sizes enhance the process of verstehen/hermeneutics advocated by interpretive researchers. The second objective of this paper is to provide a typology of effect sizes in qualitative research. Examples are given illustrating various applications of effect sizes. For instance, when conducting typological analyses, qualitative analysts only identify emergent themes; yet, these themes can be quantitized to ascertain the hierarchical structure of emergent themes. The final objective is to illustrate how inferential statistics can be utilized in qualitative data analyses. This can be accomplished by treating words arising from individuals, or observations emerging from a particular setting, as sample units of data that represent the total number of words/observations existing from that sample member/context. Heuristic examples are provided to demonstrate how inferential statistics can be used to provide more complex levels of verstehen than is presently undertaken in qualitative research. 相似文献