全文获取类型
收费全文 | 2544篇 |
免费 | 146篇 |
国内免费 | 83篇 |
专业分类
林业 | 358篇 |
农学 | 155篇 |
基础科学 | 199篇 |
145篇 | |
综合类 | 1467篇 |
农作物 | 86篇 |
水产渔业 | 120篇 |
畜牧兽医 | 102篇 |
园艺 | 71篇 |
植物保护 | 70篇 |
出版年
2024年 | 12篇 |
2023年 | 60篇 |
2022年 | 79篇 |
2021年 | 97篇 |
2020年 | 84篇 |
2019年 | 101篇 |
2018年 | 45篇 |
2017年 | 73篇 |
2016年 | 102篇 |
2015年 | 85篇 |
2014年 | 163篇 |
2013年 | 134篇 |
2012年 | 248篇 |
2011年 | 222篇 |
2010年 | 189篇 |
2009年 | 155篇 |
2008年 | 149篇 |
2007年 | 170篇 |
2006年 | 114篇 |
2005年 | 105篇 |
2004年 | 70篇 |
2003年 | 57篇 |
2002年 | 58篇 |
2001年 | 40篇 |
2000年 | 31篇 |
1999年 | 19篇 |
1998年 | 19篇 |
1997年 | 20篇 |
1996年 | 17篇 |
1995年 | 11篇 |
1994年 | 7篇 |
1993年 | 9篇 |
1992年 | 6篇 |
1991年 | 5篇 |
1990年 | 7篇 |
1989年 | 1篇 |
1988年 | 3篇 |
1987年 | 4篇 |
1982年 | 1篇 |
1962年 | 1篇 |
排序方式: 共有2773条查询结果,搜索用时 718 毫秒
31.
The analysis of China wind power industry 总被引:6,自引:0,他引:6
The development course of China wind power industry is reviewed by six stages. National policies on wind power industry are elaborated from the aspects of laws & regulations, planning, finance & taxation and electrovalence policy. And these policies have played an important supporting and regulating role in the development of wind power industry. The development status of China wind power industry is analyzed based on wind turbine installed capacity, wind power output and their growth rate. It is explained that national wind turbine manufacturers have kept developing and become strong by the data of new global installed capacity share of mainland wind turbine manufacturers in 2013 and the new global market share of 8 domestic enterprises among the world top 15 wind turbine manufacturers. But there are still 5 key problems which influence the development of national wind turbine need to be solved, including lack of top-level design, abandon and restriction wind power seriously, lack of R&D abilities, some of the key parts relying on imports and wind turbine facing a quality guarantee dilemma. Taking Sinovel Wind Group Co. Ltd. and Xinjiang Goldwind Sci & Tech Co. Ltd., the two leading companies as an example, their performance is analyzed and it’s pointed out that the wind industry must keep vigilant after the overspeed development. The enterprises should try to avoid neglecting cultivating their inner core competitive ability, including technology advancements and products reliability. Occupying the market with low price competition and expanding blindly is also not desirable. At last, the development prospects of our country’s wind power industry are analyzed and three proposals are put forward. 相似文献
32.
This papar presents an evolution model in business behaviors-the L-S Business Strategies,gives some examples and predictions which support these strategies,and analyzes the relationship between the industrial organizations in China and the L-S Business strategies. 相似文献
33.
The organization of two farmer-managed irrigation systems in the western hills of Nepal is described by examining the ways in which the activities of water allocation, water distribution, maintenance, and resource mobilization are performed. Due to the topography and environment, these two organizations are structured primarily to mobilize the large amount of labor required for maintenance of the intake and canal. Both organizations precisely define each member's water allocation. In one system, water is allocated in proportion to the area of an individual's land holding, while in the other water allocation is by purchased shares. These two cases were used to analyze the importance of the principle of water allocation for expansion of area irrigated and equity of access to irrigation. Evidence from the two systems shows that in this hill environment water allocation by purchased shares provides the individual incentive and an organizational mechanism for efficient development of irrigation resources. Expansion of area irrigated and equity of access to irrigation were found to be greater in the system which allocates water by purchased shares than where water was allocated in proportion to area irrigated. 相似文献
34.
介绍了江苏省农机作业组织基本特点与启示.阐述了农机作业组织重要性与发展机遇、发展农机作业组织重点和原则,提出了3项推进农机作业组织发展政策与措施。 相似文献
35.
36.
以农民增收、农业增效为中心,着力抓好水稻机插秧示范推广工作和组织实施“兴机富民”工程,提高跨区作业组织化程度;强化农机安全生产专项整治,规范农机市场经济秩序,促进农机化事业快速发展。 相似文献
37.
38.
随着城市经济的发展,农业、工业、生活和生态环境用水之间竞争加剧,运用市场机制和经济手段来合理分配水资源是目前国际社会所采取的战略举措。基于不同产业的用水效率和效益的差异分析,说明在产业间开展水权交易可优化水资源配置。现以工业化程度最高的上海为例,对上海的用水结构与产业结构进行对比分析,揭示水权交易的内在去驱动力,并提出了推动水权交易实践的政策建议。 相似文献
39.
随着事业单位改革的不断深入、依法行政要求的不断提高,农机安全监理机构作为履行农机安全生产行政职能的事业单位,如何通过深化改革,既确保机构和人员的稳定,又满足安全生产的要求,维护广大农民机手的切身利益,已成为农机系统广大干部职工十分关心的事情.本文从农机安全监理机构的职能、特点、改革趋向、依照公务员管理必要性阐述对农机安全监理机构改革的一些看法. 相似文献
40.
Jan L. M. H. Gerards 《Irrigation and Drainage Systems》1992,6(3):223-247
The inability to properly maintain irrigation systems over time forced the Government of Indonesia (GOI) to seek cost recovery from water users through introduction of an irrigation service fee. The plan is to introduce this fee in all of the technical irrigation systems of Indonesia, covering about 4 million hectares, over a 12 year period. Design and Introduction of this service fee in 4 pilot areas of the 4 major rice producing provinces (West, Central and East Java, and South Sulawesi) during 1989–1991 has shown that users are willing to pay. Results of first ISF collection from over 11,000 farmers in Central and East Java in pilot systems was an encouraging 95%. However that acceptance to pay by users depends on their structured and systematic involvement in defining systems needs. They need to understand a differentiation in payment if service levels are different. They appreciate use of collected funds in the system where collected. They understand the organization of water users associations but this requires their active role in fee determination and collection. They understand the establishment of federations of these associations. ISF requires also active involvement of Local Government officials as facilitators and intermediaries between service receivers (the water users) and service providers (personnel of the Public Works irrigation department) in the introduction period. This article describes the experience of the first 21 months of the ISF project, the concept developed, the principles used as basis for ISF, the introduction at the field level, issues related to acceptance by users and by the institutions involved, and the first results.Abbreviations/Acronyms DGWRD
Directorate General of Water Resources Development (Ministry of Public Works)
- EOM
Efficient Operation and Maintenance
- Gabungan
group of WUAs
- IPAIR
Indonesian abbreviation for ISF
- ISF
Irrigation Service Fee
- Juru
gate keeper
- PBB
land tax on irrigated lands
- PPL
agricultural field extension agent
- P3A
Indonesian abbreviation for Water Users Associations
- PU
Indonesian abbreviation for Public Works
- SM
Special Maintenance
- WUA
Water Users Associations 相似文献