全文获取类型
| 收费全文 | 258791篇 |
| 免费 | 16870篇 |
| 国内免费 | 643篇 |
专业分类
| 林业 | 23598篇 |
| 农学 | 14184篇 |
| 基础科学 | 2960篇 |
| 43867篇 | |
| 综合类 | 23661篇 |
| 农作物 | 16919篇 |
| 水产渔业 | 18249篇 |
| 畜牧兽医 | 102048篇 |
| 园艺 | 6294篇 |
| 植物保护 | 24524篇 |
出版年
| 2021年 | 2510篇 |
| 2020年 | 3159篇 |
| 2019年 | 4213篇 |
| 2018年 | 4424篇 |
| 2017年 | 4884篇 |
| 2016年 | 5248篇 |
| 2015年 | 4649篇 |
| 2014年 | 5964篇 |
| 2013年 | 16623篇 |
| 2012年 | 6445篇 |
| 2011年 | 8392篇 |
| 2010年 | 7661篇 |
| 2009年 | 8111篇 |
| 2008年 | 7712篇 |
| 2007年 | 6716篇 |
| 2006年 | 7215篇 |
| 2005年 | 6526篇 |
| 2004年 | 6317篇 |
| 2003年 | 6199篇 |
| 2002年 | 5471篇 |
| 2001年 | 6087篇 |
| 2000年 | 5725篇 |
| 1999年 | 5363篇 |
| 1998年 | 4136篇 |
| 1997年 | 4219篇 |
| 1996年 | 3921篇 |
| 1995年 | 4500篇 |
| 1994年 | 3904篇 |
| 1993年 | 3625篇 |
| 1992年 | 4331篇 |
| 1991年 | 4602篇 |
| 1990年 | 4268篇 |
| 1989年 | 4237篇 |
| 1988年 | 3778篇 |
| 1987年 | 3786篇 |
| 1986年 | 3752篇 |
| 1985年 | 4042篇 |
| 1984年 | 3785篇 |
| 1983年 | 3495篇 |
| 1982年 | 2911篇 |
| 1981年 | 2772篇 |
| 1980年 | 2766篇 |
| 1979年 | 3387篇 |
| 1978年 | 2997篇 |
| 1977年 | 2833篇 |
| 1976年 | 2650篇 |
| 1975年 | 2532篇 |
| 1974年 | 2717篇 |
| 1973年 | 2705篇 |
| 1972年 | 2409篇 |
排序方式： 共有10000条查询结果，搜索用时 328 毫秒
101.
102.
103.
104.
105.
106.
Ohne Zusammenfassung 相似文献
107.
108.
109.
G. L. RICHARDSON dvm T. R. O'BRIEN dvm PhD Diplomateacvr J. R. PASCOE bvsc D. M. MEAGHER dvm PhD Dipiomateacvs 《Veterinary surgery : VS》1986,15(2):156-160
The medical records of 38 horses with puncture wounds of the navicular bursa were reviewed. Only 12 horses had a satisfactory outcome (breeding or riding). Of the remaining 26 horses, 19 were euthanized, five were sold due to persistent severe lameness, one died, and one was lost to long-term follow-up. Different combinations of conservative management prior to surgical debridement and drainage of the navicular bursa were unsuccessful in resolving the condition. Horses that were treated surgically within 1 week of the injury and had a hind leg affected had the best chance of a satisfactory outcome. Additional wound debridement was necessary in 15 horses after initial surgical treatment. The most common complications encountered were navicular bone osteomyelitis and sepsis of the deep digital flexor tendon. Thirteen of 14 horses that had rupture of the deep digital flexor tendon and subluxation of the distal interphalangeal joint had an unsatisfactory outcome. One mare subsequently developed ankylosis of the distal interphalangeal joint and was a useful brood mare. Two horses that had biaxial palmar digital neurectomy because of persistent lameness were later euthanized because of navicular bone fracture and rupture of the deep digital flexor tendon. Results from limited numbers of bacterial cultures and antibiotic sensitivities suggest that penicillin and an aminoglycoside antibiotic should be used as initial antibiotic therapy. Immediate surgical debridement and appropriate antibiotic treatment are recommended as the minimum therapy for penetrating wounds of the navicular bursa in horses. 相似文献
110.
Traditional forest economics deals with regularly-ordered activities.For many reasons, however, choices must often be made amongconflicting operational priorities. In these circumstances,maximizing net discounted revenue per hectare does not maximizeglobal profit. Priorities for action should be chosen in orderof urgency index ratio, defined as the cost of delaying an operationdivided by the units of limited resource needed to undertakethe operation. Forest managers tend to use informal and sometimesconflicting rules to assign priorities among uses of limitedresources. These priorities often differ from those indicatedby urgency index ratio. Urgency index ratio can be determinedby simple calculations based on readily-available data. Theconcept can be extended to include multiple constraints. 相似文献