全文获取类型
收费全文 | 1363篇 |
免费 | 165篇 |
专业分类
林业 | 98篇 |
农学 | 25篇 |
基础科学 | 4篇 |
86篇 | |
综合类 | 19篇 |
农作物 | 29篇 |
水产渔业 | 65篇 |
畜牧兽医 | 1154篇 |
园艺 | 5篇 |
植物保护 | 43篇 |
出版年
2023年 | 25篇 |
2022年 | 9篇 |
2021年 | 18篇 |
2020年 | 78篇 |
2019年 | 32篇 |
2018年 | 66篇 |
2017年 | 58篇 |
2016年 | 48篇 |
2015年 | 48篇 |
2014年 | 86篇 |
2013年 | 89篇 |
2012年 | 79篇 |
2011年 | 50篇 |
2010年 | 53篇 |
2009年 | 69篇 |
2008年 | 50篇 |
2007年 | 54篇 |
2006年 | 39篇 |
2005年 | 36篇 |
2004年 | 32篇 |
2003年 | 23篇 |
2002年 | 36篇 |
2001年 | 42篇 |
2000年 | 29篇 |
1999年 | 34篇 |
1998年 | 18篇 |
1997年 | 23篇 |
1996年 | 25篇 |
1995年 | 28篇 |
1994年 | 18篇 |
1993年 | 22篇 |
1992年 | 32篇 |
1991年 | 31篇 |
1990年 | 24篇 |
1989年 | 21篇 |
1988年 | 15篇 |
1987年 | 22篇 |
1986年 | 7篇 |
1985年 | 15篇 |
1984年 | 12篇 |
1983年 | 12篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1974年 | 1篇 |
1972年 | 1篇 |
1969年 | 1篇 |
1968年 | 2篇 |
排序方式: 共有1528条查询结果,搜索用时 15 毫秒
21.
Evaluation of the rostral projection of the sacral lamina as a component of degenerative lumbosacral stenosis in German shepherd dogs
下载免费PDF全文
![点击此处可从《Veterinary surgery : VS》网站下载免费的PDF全文](/ch/ext_images/free.gif)
22.
23.
24.
Influence of organic phosphorus on reproductive performance and metabolic profiles of anoestrous Farafra ewes in subtropics at the end of breeding season
下载免费PDF全文
![点击此处可从《Reproduction in domestic animals》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The effect of organic phosphorus on metabolic, haematological and hormonal status, restoration of ovarian functions and conception rate in anoestrous Farafra ewes in subtropics were evaluated. Anoestrous Farafra ewes (n = 24; 34.72 ± 0.52 kg body weight) were allocated into two equal groups: control and phosphorus groups. The ewes of phosphorus group were treated with sodium 4‐dimethylamino‐2‐methyl‐phenyl‐phosphonate as an organic bound phosphorous twice a week for successive 3 weeks. Ovarian follicle development and corpora lutea were checked three times a week till occurrence of oestrus using ultrasonography while pregnancy was confirmed at 30 days post‐service. Plasma metabolites, reproductive hormones, thyroid hormones and minerals were detected at weeks ?2, ?1, 0 (mating day) and + 4 weeks post‐oestrus. Phosphorus group had significantly (p < .05) short interval to oestrous resumption if compared to control ewes (2.1 ± 0.8 weeks vs . 4.6 ± 1.1 weeks). In addition, phosphorous supplementation significantly (p < .05) increased the number of antral follicles (developed and their sizes in addition to sizes of corpora lutea (8.72 ± 0.3 mm vs . 7.46 ± 0.9 mm) as well. Number of services per conception (2.6 vs . 1.4; p < .01) was higher in control group than that of phosphorus group. Pregnancy rate (80 vs . 50%) was significantly (p < .01) higher in phosphorus group when compared to control. White blood cells in treated ewes (10.8 ± 0.44; p < .05) and monocytes (2.93 ± 0.13; p < .01) were higher than that of control group (white blood cells; 9.53 ± 0.50 and monocytes; 2.24 ± 0.14). Metabolic parameters did not differ between phosphorus and control groups during different times of treatment. It could be concluded that phosphorous administration to anoestrous Farafra ewes in subtropics could improve reproductive performance and restore ovarian activity at the end of spring and early summer. 相似文献
25.
26.
Nesma I. El-naseery Asmaa A. A. Mohammed Ahmed Awad Abuel-Atta Wael A. M. Ghonimi 《Anatomia, histologia, embryologia》2021,50(5):788-800
The oesophagus is a muscular tube comprised of cervical and thoracic regions. Several studies have clarified the histological structure of the oesophagus. However, its histoarchitecture in relation to variable dietary habits of each species is still unclear. In the current study, 21 pigeons, cattle egrets and ducks, n = 7, each was used. Macroscopically, the oesophagus of cattle egrets either the cervical or thoracic parts was the longest among the pigeons and ducks. Histologically, the oesophagus comprised of four distinct tunicae: mucosa, propria submucosa, musculosa and adventitia or serosa. A great structural variation in these layers among the three investigated species was recorded. In the cervical oesophagus of pigeons, the superficial squamous cells showed perinuclear halo zone, the propria submucosa was characteristically lacked any gland. Moreover, its musculosa was very thick. On the other hand, the intraepithelial glands were characteristically distributed along the whole length of the cattle egret’s oesophagus. Interestingly, the cervical esophagus of the ducks showed submucosal associated lymphatic tissue; diffuse and nodular Ultrastructurally, the oesophageal glands showed secretory granules of variable electron densities, electron - lucent in the pigeons and ducks and electron - dense in the cattle egrets. 相似文献
27.
28.
Differentiation between dogs with thrombosis and normal dogs using the overall hemostasis potential assay
下载免费PDF全文
![点击此处可从《Journal of Veterinary Emergency and Critical Care》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Anna L. Dengate BVSc BMedSc Marie‐Christine Morel‐Kopp PhD Julia A. Beatty PhD BVetMed BSc Vanessa Barrs BVSc MVetClinStud Jody A. Braddock BVSc MVetClinStud Richard K. Churcher BVSc Bethany J. Wilson BVSc PhD Christopher M. Ward BMedSc MBChB PhD 《Journal of Veterinary Emergency and Critical Care》2016,26(3):446-452
29.
Thromboelastographic assessment of the contribution of platelets and clotting proteases to the hypercoagulable state of dogs with immune‐mediated hemolytic anemia
下载免费PDF全文
![点击此处可从《Journal of Veterinary Emergency and Critical Care》网站下载免费的PDF全文](/ch/ext_images/free.gif)
30.