全文获取类型
收费全文 | 177812篇 |
免费 | 9670篇 |
国内免费 | 116篇 |
专业分类
林业 | 7476篇 |
农学 | 5343篇 |
基础科学 | 1150篇 |
20588篇 | |
综合类 | 32683篇 |
农作物 | 6640篇 |
水产渔业 | 8695篇 |
畜牧兽医 | 90646篇 |
园艺 | 2152篇 |
植物保护 | 12225篇 |
出版年
2018年 | 2217篇 |
2017年 | 2458篇 |
2016年 | 2296篇 |
2015年 | 2030篇 |
2014年 | 2453篇 |
2013年 | 6489篇 |
2012年 | 4703篇 |
2011年 | 5748篇 |
2010年 | 3634篇 |
2009年 | 3726篇 |
2008年 | 5654篇 |
2007年 | 5444篇 |
2006年 | 5231篇 |
2005年 | 4894篇 |
2004年 | 4760篇 |
2003年 | 4765篇 |
2002年 | 4598篇 |
2001年 | 5509篇 |
2000年 | 5341篇 |
1999年 | 4333篇 |
1998年 | 1735篇 |
1997年 | 1757篇 |
1996年 | 1675篇 |
1995年 | 2037篇 |
1994年 | 1846篇 |
1993年 | 1789篇 |
1992年 | 3673篇 |
1991年 | 3789篇 |
1990年 | 3827篇 |
1989年 | 3810篇 |
1988年 | 3518篇 |
1987年 | 3612篇 |
1986年 | 3705篇 |
1985年 | 3577篇 |
1984年 | 3029篇 |
1983年 | 2714篇 |
1982年 | 1842篇 |
1981年 | 1727篇 |
1979年 | 2736篇 |
1978年 | 2254篇 |
1977年 | 1928篇 |
1976年 | 1785篇 |
1975年 | 1884篇 |
1974年 | 2573篇 |
1973年 | 2482篇 |
1972年 | 2487篇 |
1971年 | 2262篇 |
1970年 | 2096篇 |
1969年 | 1998篇 |
1967年 | 1672篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
961.
962.
R E Werner A J Straughan D Vezin 《Journal of the American Veterinary Medical Association》1992,200(1):64-66
Nylon cable bands used as ligatures caused postsurgical complications in 5 ovariohysterectomized bitches. Clinical signs included fever, stiffness, strangury, draining fistulae, vaginal discharge, and tenesmus. Most signs first appeared several years after surgery, and all signs were resolved after removal of the bands. On the basis of our experience, we suggest that nylon cable bands not be used for ovariohysterectomy ligations. 相似文献
963.
Morphology and distribution of water and lipid were examined in menisci of growing swine. The broadness of menisci and the size of protruded tissue in the inner anterior portion of menisci varied among animals. Small tears of tissues were frequently observed. Both the thickness and tissue weight were greater in the lateral than in the medial meniscus. Water content and intensity of glycosaminoglycan staining with safranin-O were found to be greatest in the inner one-third of the meniscus, and greater in the middle than in the outer one-third of the meniscus. Lipid content was greater in the outer one-third than in the inner two-thirds of the meniscus. 相似文献
964.
J.A Stegeman M.C.M De Jong H.M.J.F Van Der Heijden A.R.W Elbers T.G Kimman 《Research in veterinary science》1996,61(3):263-267
The performance of tests for the detection of antibodies to Aujeszky's disease virus glycoprotein E (ge) in a target population was evaluated by constructing and analysing receiver operating characteristic (roc) curves. These curves assess the discriminating ability of a test over the entire range of test signals. The advantages of applying the analysis to a sample of the target population (all commercial pigs in the Netherlands), as compared to using a panel of test sera, are that the estimates of sensitivity and specificity, the comparisons between tests and the choices of the cut-off values are all relevant for the target population. The results of a gE-elisa in colostrum (test A) and in a single droplet of whole blood (test B) were compared with the results obtained with the same elisa in serum (gold standard). The area under the ROC curve, which is a quantitative measure of test performance, was significantly (P<0·01) smaller with test A than test B or the gold standard, indicating that test B performed better than test A. No significant difference was observed between test B and the gold standard. 相似文献
965.
966.
967.
968.
969.
970.
Retained foetal membranes in dairy herds in the Huntly district 总被引:4,自引:0,他引:4
K Moller P E Newling H J Robson G J Jansen J A Meursinge M G Cooper 《New Zealand veterinary journal》1967,15(7):111-116