全文获取类型
收费全文 | 1330篇 |
免费 | 3篇 |
国内免费 | 3篇 |
专业分类
财政金融 | 113篇 |
工业经济 | 42篇 |
计划管理 | 93篇 |
经济学 | 164篇 |
综合类 | 10篇 |
运输经济 | 2篇 |
旅游经济 | 2篇 |
贸易经济 | 73篇 |
农业经济 | 7篇 |
经济概况 | 34篇 |
水利工程 | 796篇 |
出版年
2022年 | 2篇 |
2021年 | 1篇 |
2020年 | 2篇 |
2019年 | 1篇 |
2018年 | 5篇 |
2016年 | 4篇 |
2015年 | 2篇 |
2014年 | 20篇 |
2013年 | 12篇 |
2012年 | 95篇 |
2011年 | 123篇 |
2010年 | 26篇 |
2009年 | 16篇 |
2008年 | 22篇 |
2007年 | 39篇 |
2006年 | 29篇 |
2005年 | 42篇 |
2004年 | 35篇 |
2003年 | 54篇 |
2002年 | 30篇 |
2001年 | 26篇 |
2000年 | 65篇 |
1999年 | 62篇 |
1998年 | 68篇 |
1997年 | 69篇 |
1996年 | 61篇 |
1995年 | 53篇 |
1994年 | 54篇 |
1993年 | 61篇 |
1992年 | 79篇 |
1991年 | 21篇 |
1990年 | 17篇 |
1989年 | 18篇 |
1988年 | 6篇 |
1987年 | 8篇 |
1986年 | 6篇 |
1985年 | 11篇 |
1984年 | 14篇 |
1983年 | 22篇 |
1982年 | 12篇 |
1981年 | 17篇 |
1980年 | 4篇 |
1979年 | 8篇 |
1978年 | 4篇 |
1977年 | 3篇 |
1976年 | 1篇 |
1975年 | 2篇 |
1971年 | 1篇 |
1969年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有1336条查询结果,搜索用时 7 毫秒
991.
992.
尽管水稻栽培技术在整个东南亚都是相似的,但是,据说远东地区主要通过进步的综合农业技术,其好处几倍于东南亚。与东南亚相反,印度农民发现,单一栽种水稻投入大量的物力和人力而所获甚少,即使在很小的土地上,用充足的水进行灌溉栽培也是十分不合算的。 相似文献
993.
HYDROELASTICITYTHEORIESOFSLENDERFLOATINGSTRUCTURESXiaJin-zhuSupervisor:Prof.WuYou-sheng(ChinaShipScientificResearchCenter,P.O... 相似文献
994.
THESTATISTICCHARACTERISTICSOFIRREGULARBREAKINGWAVEFORCESONVERTICALWALLS¥LiYu-cheng;LiuDa-zhong(Dept.ofCivilEngineering,Dalian... 相似文献
995.
Collaboration rules 总被引:1,自引:0,他引:1
Corporate leaders seeking to boost growth, learning, and innovation may find the answer in a surprising place: the Linux open-source software community. Linux is developed by an essentially volunteer, self-organizing community of thousands of programmers. Most leaders would sell their grandmothers for workforces that collaborate as efficiently, frictionlessly, and creatively as the self-styled Linux hackers. But Linux is software, and software is hardly a model for mainstream business. The authors have, nonetheless, found surprising parallels between the anarchistic, caffeinated, hirsute world of Linux hackers and the disciplined, tea-sipping, clean-cut world of Toyota engineering. Specifically, Toyota and Linux operate by rules that blend the self-organizing advantages of markets with the low transaction costs of hierarchies. In place of markets' cash and contracts and hierarchies' authority are rules about how individuals and groups work together (with rigorous discipline); how they communicate (widely and with granularity); and how leaders guide them toward a common goal (through example). Those rules, augmented by simple communication technologies and a lack of legal barriers to sharing information, create rich common knowledge, the ability to organize teams modularly, extraordinary motivation, and high levels of trust, which radically lowers transaction costs. Low transaction costs, in turn, make it profitable for organizations to perform more and smaller transactions--and so increase the pace and flexibility typical of high-performance organizations. Once the system achieves critical mass, it feeds on itself. The larger the system, the more broadly shared the knowledge, language, and work style. The greater individuals' reputational capital, the louder the applause and the stronger the motivation. The success of Linux is evidence of the power of that virtuous circle. Toyota's success is evidence that it is also powerful in conventional companies. 相似文献
996.
997.
998.
999.
A new chelating material dialdehyde m-phenylenediamine starch (DASMPA) was synthesized by reacting m-phenylenediamine with dialdehyde starch. The obtained material was characterized by element analysis and Fourier transform infrared (FT-IR) spectra. The FT-IR of DASMPA showed an absorption peak at 1605.95 cm(-1) indicating the formation of a Schiff base (C=N). Adsorption activity of DASMPA for Zn(2+) was also investigated in terms of contact time, pH, the initial Zn(II) concentration and temperature, the results revealed that pH = 5, t = 1 h were the optimal conditions. With the degree of substitution (DS) of the DASMPA increased, the adsorption capacity increased gradually. The adsorption equilibrium data correlated well with Freundlich isotherm. Moreover, lower temperature was preferable for the process as it was exothermic. 相似文献
1000.
Lazarova V Martin Ruel S Barillon B Dauthuille P 《Water science and technology》2012,66(10):2056-2064
This paper aims to demonstrate the relevance of membrane bioreactor (MBR) technology for the reduction of the environmental footprint of wastewater treatment in terms of removal of microbial and organic trace pollutants with increased reliability of operation. The application of a holistic approach using failure mode analysis, life cycle analysis (LCA), water quality fingerprints and environmental impacts underlines the lower environmental footprint of MBRs compared with conventional activated sludge. Several elements of this empirical approach can be included to upgrade the existing LCA tools in order to include the reduction of eco-toxicity, better human health protection and water reuse. 相似文献