全文获取类型
| 收费全文 | 4609篇 |
| 免费 | 322篇 |
| 国内免费 | 1篇 |
专业分类
| 林业 | 303篇 |
| 农学 | 128篇 |
| 基础科学 | 36篇 |
| 812篇 | |
| 综合类 | 862篇 |
| 农作物 | 195篇 |
| 水产渔业 | 232篇 |
| 畜牧兽医 | 1920篇 |
| 园艺 | 109篇 |
| 植物保护 | 335篇 |
出版年
| 2023年 | 32篇 |
| 2022年 | 31篇 |
| 2021年 | 66篇 |
| 2020年 | 77篇 |
| 2019年 | 83篇 |
| 2018年 | 98篇 |
| 2017年 | 90篇 |
| 2016年 | 113篇 |
| 2015年 | 80篇 |
| 2014年 | 121篇 |
| 2013年 | 203篇 |
| 2012年 | 231篇 |
| 2011年 | 285篇 |
| 2010年 | 182篇 |
| 2009年 | 155篇 |
| 2008年 | 256篇 |
| 2007年 | 246篇 |
| 2006年 | 262篇 |
| 2005年 | 243篇 |
| 2004年 | 190篇 |
| 2003年 | 226篇 |
| 2002年 | 182篇 |
| 2001年 | 75篇 |
| 2000年 | 81篇 |
| 1999年 | 86篇 |
| 1998年 | 52篇 |
| 1997年 | 43篇 |
| 1996年 | 50篇 |
| 1995年 | 37篇 |
| 1994年 | 31篇 |
| 1993年 | 33篇 |
| 1992年 | 40篇 |
| 1991年 | 56篇 |
| 1990年 | 51篇 |
| 1989年 | 46篇 |
| 1988年 | 39篇 |
| 1987年 | 60篇 |
| 1986年 | 40篇 |
| 1985年 | 59篇 |
| 1984年 | 38篇 |
| 1983年 | 46篇 |
| 1982年 | 25篇 |
| 1981年 | 22篇 |
| 1980年 | 24篇 |
| 1979年 | 34篇 |
| 1978年 | 25篇 |
| 1976年 | 26篇 |
| 1973年 | 27篇 |
| 1970年 | 24篇 |
| 1969年 | 31篇 |
排序方式： 共有4932条查询结果，搜索用时 15 毫秒
941.
942.
943.
944.
945.
946.
Analgesic efficacy of an oral transmucosal spray formulation of meloxicam alone or in combination with tramadol in cats with naturally occurring osteoarthritis 
下载免费PDF全文
下载免费PDF全文 947.
Six cannulated Salers steers (305 +/- 17 kg initial BW) were used in a double 3 x 3 Latin square design to compare the effects of the nature of the cereal (wheat vs corn) and the corn genotype (dent vs flint) on rate, site, and extent of digestion of high-concentrate diets. The cereals were coarsely cracked, and the diets were balanced to have the same percentage of starch (47.7 +/- 2.3%) and CP (14.6 +/- .7%). Differences in ruminal starch digestion were observed between wheat- and corn-based diets (86.6 vs 47.8%; P < .001) and between corn genotypes (60.8 vs 34.8% for dent and flint corns; P < .001). For flint corn, more than half the starch was digested in the hindgut. Total tract digestion of starch was greater (P < .001) by steers fed wheat than by those fed corn and did not differ (P > .1) between the two corn genotypes. Ruminal mean pH (P < .01) was lower and total VFA concentration (P < .1) was higher for wheat- than for corn-based diets. Ruminal acetate:propionate tended to increase with the decrease in the amount of starch degraded in the rumen, but differences were not significant (P > .1). When wheat replaced corn, nonammonia, nonmicrobial N duodenal flow decreased (P < .01), and microbial duodenal flow increased (P < .05), so there were no differences in the duodenal flow of nonammonia N duodenal flow (P > .1). The lower nonammonia N duodenal flow for the dent corn- than for the flint corn-based diet (P < .05) was related to a lower passage of nonammonia, nonmicrobial N into the duodenum. Efficiency of microbial protein synthesis was inversely correlated with the amount of starch degraded in the rumen. Nature of the cereal, wheat vs corn, and genotype of the corn, dent vs flint, alter the site and extent of starch digestion. 相似文献
948.
949.
950.
Five outbreaks of myocarditis were investigated in young sheep. They occurred during late winter and spring when there was lush growth of pasture following a prolonged period of drought. Clinically the disease was characterised by sudden death and pathological findings were dominated by acute multifocal locally extensive necrotising and haemorrhagic myocarditis. A fluorescent antibody technique was used to demonstrate the presence of Clostridium chauvoei in paraffin embedded sections of myocardium from 4 of the outbreaks. 相似文献