全文获取类型
收费全文 | 204篇 |
免费 | 8篇 |
专业分类
林业 | 1篇 |
农学 | 1篇 |
基础科学 | 3篇 |
1篇 | |
综合类 | 12篇 |
水产渔业 | 3篇 |
畜牧兽医 | 187篇 |
植物保护 | 4篇 |
出版年
2023年 | 1篇 |
2021年 | 1篇 |
2020年 | 4篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2017年 | 2篇 |
2016年 | 4篇 |
2015年 | 4篇 |
2014年 | 5篇 |
2013年 | 12篇 |
2012年 | 3篇 |
2011年 | 7篇 |
2010年 | 5篇 |
2009年 | 5篇 |
2008年 | 9篇 |
2007年 | 12篇 |
2006年 | 7篇 |
2005年 | 7篇 |
2004年 | 8篇 |
2003年 | 7篇 |
2002年 | 7篇 |
2001年 | 12篇 |
2000年 | 6篇 |
1999年 | 10篇 |
1998年 | 5篇 |
1997年 | 7篇 |
1996年 | 9篇 |
1995年 | 4篇 |
1994年 | 1篇 |
1993年 | 6篇 |
1992年 | 4篇 |
1991年 | 11篇 |
1990年 | 8篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 3篇 |
1979年 | 1篇 |
排序方式: 共有212条查询结果,搜索用时 15 毫秒
211.
PG Blanco D Arias A Rube JP Barrena Y Corrada C Gobello 《Reproduction in domestic animals》2009,44(S2):164-166
The aim of this study was to describe the changes in the resistance index (RI) and systolic/diastolic ratio ( S / D ) of the uterine arteries during mid-pregnancy abortion induction in the dog. Sixteen 30–35 day pregnant bitches were randomly assigned to either a pharmacological protocol to interrupt gestation (n = 8) or were used as untreated control group (n = 8). Doppler assessments of uterine arteries blood flow were carried out before the initiation of the protocol and then every other day up to abortion (treated group) or parturition (control group). All treated bitches aborted 6 ± 1.2 days after initiation of the treatment (while none of the non-treated bitches aborted). Pre-treatment RI and S / D did not differ between groups (p > 0.2) while average post-treatment indexes were (mean ± SD): 0.62 ± 0.1 vs 0.53 ± 0.1 (p < 0.01) and 2.96 ± 0.9 vs 2.23 ± 0.3 (p = 0.01), for the treated and non-treated group respectively. Correlations between days to abortion and RI or S / D were 0.75 (p < 0.01) and 0.79 (p < 0.01) and, −0.78 (p < 0.01) and −0.73 (p < 0.01) for the treated and non-treated groups respectively. In the treated group, correlations between serum progesterone (P4 ) concentrations and RI and S / D were −0.76 (p < 0.01) and −0.59 (p < 0.01) respectively. It is concluded that, during induction of abortion, RI and S / D of uterine arteries progressively increased while P4 decreased. 相似文献
212.
Armando García-Ortega Johan Verreth Karen Vermis Hans J. Nelis Patrick Sorgeloos Martin Verstegen 《Aquaculture International》2010,18(2):119-134
Temporary accumulation of ascorbic acid 2-sulfate (AAS) was measured to estimate food intake and gut evacuation in larvae
of African catfish. Fish larvae were fed decapsulated cysts of Artemia containing AAS. In a first experiment it was found that no biosynthesis of AAS occurs in the larvae of this species. In a
second experiment, the gut contents of the fish larvae fed were calculated as they changed during development. In a third
experiment, the gut evacuation rate of fish larvae was determined during continuous and discontinuous feeding regimes in the
first five days after the start of exogenous feeding. Food consumption by catfish larvae increased from 46.5% of their body
dry weight (BDW) on day 1 after the start of exogenous feeding to 53.8% BDW on day 3. Thereafter, food consumption decreased
to 27.8% BDW on day 5. A similar pattern was observed for gut evacuation, which increased during the first days of exogenous
feeding and decreased as fish growth continued. The rate of gut evacuation in a continuous feeding regime was significantly
higher (P < 0.05) than that under discontinuous feeding. On day 1 post-hatch and 7 h after first food ingestion the fish larvae evacuated
87% of the food in continuous feeding compared with 43% under discontinuous feeding. It was found that gut emptying differs
during larval development. Under continuous feeding, on days 1 and 3 post-hatch and 11 h after the first meal 90% of the food
was evacuated compared with 71% evacuated on day 5. The advantages and limitations of the AAS method for estimation of food
consumption by fish larvae are discussed. 相似文献