全文获取类型
收费全文 | 481篇 |
免费 | 29篇 |
国内免费 | 35篇 |
专业分类
林业 | 60篇 |
农学 | 26篇 |
基础科学 | 61篇 |
48篇 | |
综合类 | 260篇 |
农作物 | 20篇 |
水产渔业 | 13篇 |
畜牧兽医 | 26篇 |
园艺 | 11篇 |
植物保护 | 20篇 |
出版年
2024年 | 4篇 |
2023年 | 10篇 |
2022年 | 11篇 |
2021年 | 23篇 |
2020年 | 12篇 |
2019年 | 15篇 |
2018年 | 11篇 |
2017年 | 17篇 |
2016年 | 20篇 |
2015年 | 22篇 |
2014年 | 24篇 |
2013年 | 23篇 |
2012年 | 43篇 |
2011年 | 35篇 |
2010年 | 27篇 |
2009年 | 31篇 |
2008年 | 32篇 |
2007年 | 42篇 |
2006年 | 28篇 |
2005年 | 24篇 |
2004年 | 21篇 |
2003年 | 13篇 |
2002年 | 8篇 |
2001年 | 6篇 |
2000年 | 2篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 4篇 |
1994年 | 7篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1990年 | 3篇 |
1989年 | 4篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1985年 | 1篇 |
排序方式: 共有545条查询结果,搜索用时 375 毫秒
1.
2.
区域旅游资源开发定位研究——以内蒙古赤峰市为例 总被引:7,自引:1,他引:7
区域旅游资源开发是发展区域旅游的基础 ,开发的定位研究有助于为一地旅游业的发展指明方向。本文从区域角度和空间经济一体化思想出发 ,以赤峰市为例 ,通过对旅游资源的定量与定性研究 ,得到旅游资源的综合评价图式 ,结合区际分析归纳出赤峰市旅游资源开发利用的方向和层次。从而为区域旅游开发的定位研究进行了一般理论的探讨及例证分析 相似文献
3.
Ludwig John A. Eager Robert W. Bastin Gary N. Chewings Vanessa H. Liedloff Adam C. 《Landscape Ecology》2002,17(2):157-171
The cover, number, size, shape, spatial arrangement and orientation of vegetation patches are attributes that have been used
to indicate how well landscapes function to retain, not ‘leak’, vital system resources such as rainwater and soil. We derived
and tested a directional leakiness index (DLI) for this resource retention function. We used simulated landscape maps where
resource flows over map surfaces were directional and where landscape patch attributes were known. Although DLI was most strongly
related to patch cover, it also logically related to patch number, size, shape, arrangement and orientation. If the direction
of resource flow is multi-directional, a variant of DLI, the multi-directional leakiness index (MDLI) can be used. The utility
of DLI and MDLI was demonstrated by applying these indices to three Australian savanna landscapes differing in their remotely
sensed vegetation patch attributes. These leakiness indices clearly positioned these three landscapes along a function-dysfunction
continuum, where dysfunctional landscapes are leaky (poorly retain resources).
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
4.
《东北农业大学学报(英文版)》2016,(2):82-88
Along with the rapid advance of industrialization and urbanization process, fostering new agricultural business entities become inevitable for agricultural transformation and the construction of agricultural modernization in China. The status of the new agricultural business entities determines the level of modern agricultural development. In recent years, new agricultural business entities have grew rapidly. However, there are still many problems including the difficulties in financing loans, inadequate agricultural insurance system, bad implementation of agricultural subsidies, jagged agricultural talents and so on. In order to foster new agricultural business entities, countermeasures should be carried out to ensure financial support, perfect the agricultural insurance, strengthen the level of agricultural subsidies, strive to develop the degree of specialization agricultural operators and so on. 相似文献
5.
In order to subdivide the market during the process of project planning and orient the group of client, then determine the sale price; on the condition that the traditional orientation procedure cant grasp the payment capability of the aim client, the anthors can adapt the powerful finance analysis ability of EXEL to design the procedure of determining the purchasing power and payments ability of the aim client, and shape a set of orientation system based on quantitative analysis method. The result is, the character of the aim client can be grasp accurately depend on this orientation system, and providing a scientific gist for the accurate orientation of price and lowing the risk of investment etc. 相似文献
6.
小区播种机的研究现状及发展方向 总被引:8,自引:0,他引:8
种子的质量是保证粮食丰产丰收的根本,小区播种机的性能又是新品种培育的保证。为此,就当前国内外小区播种机的发展现状及我国小区播种机现阶段遇到的问题进行了分析,并对小区播种机排种器等部件进行了重点介绍,最后对我国小区播种机的发展方向进行了展望。 相似文献
7.
杜景茹 《农业图书情报学刊》2010,22(10):281-283
高校图书馆专业分馆是高校教学、科研必不可少的情报机构,在高校教学、科研中有着不可替代的作用。论述了高校图书馆专业分馆的地位和作用,建构原则与目标,分析了高校图书馆专业分馆管理的现状、特点,并详细阐述了专业分馆建设和发展方向。 相似文献
8.
吴正荣 《云南农业大学学报(自然科学版)》2010,4(5):100-103,114
"儒士"自觉地承担着儒家的社会意识,而"僧人"则以完成生命的超越为己任。在三教合流的传统中,"儒士"和"僧人"的内在文化构成并不具备严格意义上的界分,常常互有融含。故而,论述时只能抽象出其"共相"意义上的概念,各置于"儒""释"系统中剖析其最高价值追求,得出儒士诗重社会伦理,而僧人诗则重解构文化局限,求证生命本源的结论。 相似文献
9.
10.
《Scandinavian Journal of Forest Research》2012,27(8):784-796
Corporate social responsibility (CSR) has been a topic of interest to both practitioners and researchers in the forest products sector. However, the existing literature falls short of examining the connections between CSR implementation and firm cultures, a key link to further our understanding for CSR implementation. This current study investigates the relationship between firm cultures and CSR implementation in the global forest, paper & packaging industry companies. Specifically, the authors propose firm cultures, including market orientation, learning orientation and innovativeness potentially support CSR implementation. Also, innovativeness is proposed to mediate the market orientation-CSR and learning orientation-CSR relationships. Data are collected through a mail survey with responses from 58 companies (87 individuals) of the Top 100 global forest, paper & packaging industry companies, identified by PricewaterhouseCoopers in its 2008 Global Forest, Paper & Packaging Industry Survey. Results confirm the hypothesized relationships between market orientation and CSR and learning orientation and CSR. However, the proposed mediating effect of innovativeness is not significant. 相似文献