全文获取类型
收费全文 | 1775篇 |
免费 | 134篇 |
国内免费 | 25篇 |
专业分类
林业 | 127篇 |
农学 | 94篇 |
基础科学 | 115篇 |
148篇 | |
综合类 | 1218篇 |
农作物 | 46篇 |
水产渔业 | 21篇 |
畜牧兽医 | 109篇 |
园艺 | 23篇 |
植物保护 | 33篇 |
出版年
2024年 | 8篇 |
2023年 | 40篇 |
2022年 | 67篇 |
2021年 | 63篇 |
2020年 | 86篇 |
2019年 | 73篇 |
2018年 | 32篇 |
2017年 | 73篇 |
2016年 | 84篇 |
2015年 | 77篇 |
2014年 | 143篇 |
2013年 | 159篇 |
2012年 | 187篇 |
2011年 | 172篇 |
2010年 | 112篇 |
2009年 | 123篇 |
2008年 | 102篇 |
2007年 | 81篇 |
2006年 | 70篇 |
2005年 | 44篇 |
2004年 | 22篇 |
2003年 | 25篇 |
2002年 | 17篇 |
2001年 | 15篇 |
2000年 | 7篇 |
1999年 | 6篇 |
1998年 | 4篇 |
1997年 | 5篇 |
1996年 | 3篇 |
1995年 | 12篇 |
1994年 | 4篇 |
1993年 | 7篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 4篇 |
1988年 | 2篇 |
排序方式: 共有1934条查询结果,搜索用时 31 毫秒
41.
《农业图书情报学刊》2012,24(7)
通过对海南省四个市9个村600户村民信息需求类型、获取信息的方式等调查数据进行统计分析,发现海南省农民信息需求呈现出多样化、重点突出、范围广等特点,但由于受到各种因素的影响,农民的信息获取满意度并不高。海南省一半以上农民认为限制其获取信息的因素是"害怕假信息"。为此,作者提出了通过培养农民的信息获取和识别能力、提供丰富的信息获取渠道、加大政府的扶持宣传力度、加强农业技能培训等方式,以更好地满足农民信息需求。 相似文献
42.
Oto J. Okwu 《Journal Of Agricultural & Food Information》2013,14(3-4):315-328
This study characterized farmer users and nonusers of mass media as channels of agricultural information. A structured interview was used to obtain data from 316 randomly selected farmers in Benue State, Nigeria. The data were subjected to discriminant analysis and the following socioeconomic characteristics significantly differed at a 5% level of probability between users and nonusers of mass media (and their F-ratio values): education (6.30), income (5.12), gender (4.84), and socioeconomic status (4.83). Farmer users of mass media are therefore those who have good level of education, belong to a relatively high income bracket, and are typically male and of a relatively high socioeconomic status. Farmers’ socioeconomic characteristics should be considered in planning mass media usage in agricultural information dissemination. 相似文献
43.
新中国成立后,浙江乡村科技事业发展经历了建国初期的恢复、人民公社时期的"大跃进"以及改革开放后的跨越式发展期。梳理浙江乡村科技事业发展历程,从中概括其先进经验和启示,为中西部欠发达地区乡村科技事业建设提供借鉴,具有重要的实践意义。 相似文献
44.
Hüttner K Leidl K Pfeiffer DU Jere FB Kasambara D 《Tropical animal health and production》2001,33(3):201-218
The social background, farm characteristics, indicators of income and self-evaluation returns of 96 randomly selected users of a Basic Animal Health Service (BAHS) programme in northern Malawi were compared with those of 96 matched past-users and 96 non-users, respectively. All 288 farms were visited between July and October 1997. Data analysis was performed using univariate and multivariate techniques. The results showed that, on average, BAHS users had larger cattle herds (16.3) than part-users (14.7) or non-users (12.4). Similarly, the annual yields of crops were higher for users compared to either of the other groups. Users occupied better houses and owned a larger number of farm and household items than did part-users or non-users. A third of all farmers were engaged in additional income generation to lessen the risk of poverty. However, analysis of the livestock management and the educational background of the farmers suggested that usage of the BAHS programme was not only determined by already existing `wealth'. Improved livestock husbandry and management measures, which do not require capital investment, were more frequently applied by users compared to either of the other groups. Non-users and part-users had attained a lower level of education, were less open towards improved farming methods and felt less knowledgeable than BAHS users. The average straight-line distances from farms using BAHS to their respective village animal health worker (2.2 km) or veterinary assistant (2.9 km) were similar but varied according to ecological zone. Intensified extension and awareness meetings in villages will be required to get more non-users involved in BAHS. 相似文献
45.
Pedersen HD Häggström J Falk T Mow T Olsen LH Iversen L Jensen AL 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》1999,13(1):56-64
Observer variation in diagnosing mild mitral regurgitation in dogs by cardiac auscultation was assessed by having 6 veterinarians with different levels of experience examine 57 Cavalier King Charles Spaniels. Comparisons with color Doppler echocardiography and phonocardiography were made, and the effects of 2 physical maneuvers on the auscultatory findings were evaluated. Using mildly diseased dogs, interobserver agreement in diagnosing the presence or absence of left-sided murmurs ranged from 63% to 88%. The agreement with phonocardiography (range, 53-91%) increased with the amount of observer experience. The 2 most experienced observers could discern soft ejection murmurs from regurgitant murmurs and were able to diagnose 89% of the dogs with regurgitant jets larger than 30% of the left atrial area. In general, less experienced observers diagnosed most jets larger than 50%. In many dogs with small jets, no murmur was found by auscultation and phonocardiography. The audibility of mild regurgitation was significantly reduced in dogs that were difficult to auscultate. Early systolic murmurs were typical of mild regurgitation, whereas holosystolic murmurs typified severe regurgitation. In a few dogs, late systolic murmurs alternated with holosystolic murmurs. Systolic clicks were found phonocardiographically in 18 dogs with mild to moderate regurgitation, but the audibility apparently was low. In many mildly affected dogs, physical maneuvers increased murmur intensity. Thus, some form of dynamic auscultation might facilitate the diagnosis of mild regurgitation. Auscultatory findings in mild regurgitation appear to depend on observer experience, circulatory status, and how difficult the dog is to auscultate. 相似文献
46.
国外土地整理实践对我国土地整理的启示 总被引:1,自引:0,他引:1
土地整理在我国起步较晚,很多理论还不成熟。采用文献参阅法,从土地整理的发展阶段、内容和特点等方面介绍了德国、俄国和荷兰等国外土地整理的基本情况,并由此得出其对我国土地整理的启示:建立健全土地整理法律政策,重视土地整理的权属调整,拓宽土地整理融资渠道,重视土地整理中的生态环境保护,积极推动土地整理公众参与和高度重视土地整理规划等。 相似文献
47.
数控技术是用数字信息对机械运动和工作过程进行控制的技术,数控装备是以数控技术为代表的新技术对传统制造产业和新兴制造业的渗透形成的机电一体化产品,数控技术的广泛应用不但给传统制造业带来了革命性的变化,也给中国的高的教育发展起到了促进作用。文章结合我院数控实训教学的现状及笔者多年从事数控实训教学工作经验,总结了数控实训教学过程中的几点心得,旨在促进教学效果的提高,推进技能型人才培养的速度和质量。 相似文献
48.
49.
文毅 《农业图书情报学刊》2008,20(7)
2000年以来升格的本科新院校先后迎来教育部"本科教学工作水平评估".西部新院校图书馆要确保达到"管理手段先进、图书馆使用效果好"和"生均藏书量100册、生均年进书量4册"的标准,时间紧,任务重,压力大.除争取学院加大投入外,必须准确理解、分解评估指标.硬件从实,软件从严.从实盘底,及时调整.艰苦奋斗,突出特点.避免突击采购,又好又快地建设数字化图书馆. 相似文献
50.
针对机插秧发展速度较慢的实际,东港市抓住国家实施农机购置补贴政策的机遇,把水稻机插秧列为水稻全程机械化的重点工作,采取政府主导、补贴拉动、基地示范、宣传推广、技术培训、目标考核等举措,推动全市水稻全程机械化发展,为各地水稻机插秧技术的推广提供了经验。同时,对机插秧技术推广过程中存在的一些问题进行了剖析,以便为下一步解决问题提供依据。 相似文献