全文获取类型
收费全文 | 396篇 |
免费 | 14篇 |
国内免费 | 1篇 |
专业分类
林业 | 126篇 |
农学 | 3篇 |
66篇 | |
综合类 | 46篇 |
农作物 | 7篇 |
水产渔业 | 23篇 |
畜牧兽医 | 115篇 |
园艺 | 4篇 |
植物保护 | 21篇 |
出版年
2020年 | 4篇 |
2019年 | 4篇 |
2017年 | 4篇 |
2016年 | 4篇 |
2015年 | 4篇 |
2014年 | 7篇 |
2013年 | 9篇 |
2012年 | 13篇 |
2011年 | 20篇 |
2010年 | 8篇 |
2009年 | 16篇 |
2008年 | 19篇 |
2007年 | 10篇 |
2006年 | 9篇 |
2005年 | 14篇 |
2004年 | 15篇 |
2003年 | 11篇 |
2002年 | 14篇 |
2001年 | 9篇 |
2000年 | 8篇 |
1999年 | 4篇 |
1996年 | 4篇 |
1992年 | 4篇 |
1991年 | 5篇 |
1990年 | 4篇 |
1989年 | 5篇 |
1988年 | 4篇 |
1987年 | 5篇 |
1985年 | 4篇 |
1984年 | 5篇 |
1983年 | 4篇 |
1979年 | 4篇 |
1975年 | 3篇 |
1973年 | 4篇 |
1971年 | 4篇 |
1969年 | 3篇 |
1967年 | 5篇 |
1965年 | 3篇 |
1959年 | 9篇 |
1953年 | 6篇 |
1942年 | 3篇 |
1937年 | 11篇 |
1936年 | 9篇 |
1934年 | 4篇 |
1933年 | 4篇 |
1932年 | 3篇 |
1931年 | 16篇 |
1930年 | 4篇 |
1929年 | 10篇 |
1928年 | 6篇 |
排序方式: 共有411条查询结果,搜索用时 156 毫秒
1.
Ernst Knippel Röhrl Schüpster Schaile und Fabricius 《Forstwissenschaftliches Centralblatt》1927,49(19):687-703
Ohne Zusammenfassung 相似文献
2.
Martin Kramer Dr. Med. Vet Martin Gerwing Dr. Med. Vet Volker Hach Dr. Med. Vet Ernst Schimke Prof. Dr. Med. Vet 《Veterinary radiology & ultrasound》1997,38(2):139-149
Sonography of the musculoskeletal system in dogs and cats was undertaken to evaluate the application of this imaging procedure in orthopedics. In most of the patients a 7,5 MHz linear transducer was used because of its flat application surface and its resolving power. The evaluation of bone by sonography is limited, but sonography can provide addition information regarding the bone surface and surrounding soft tissue. Ultrasound is valuable for assessing joint disease. Joint effusion, thickening of the joint capsule and cartilage defects can be identified sonographically. It is also possible to detect bone destruction. Instabilities are often identified with the help of a dynamic examination. Soft tissue abnormalities of the musculoskeletal system lend themselves to sonographic evaluation. Partial or complete muscles or tendon tears are able to be differentiated and the healing process can be monitored. Most of the diseases that are in the area of the biceps or the achilles tendon, such as dislocation of the tendon, old injuries with scarification, free dissecates in the tendonsheath, tendinitis and/or tendosynovitis can be differentiated by sonography. In addition, with clinical and laboratory findings, it is often possible to make a correct diagnosis with ultrasound in patients with abscesses, foreign bodies, hematomas, soft tissue tumors and lipomas. 相似文献
3.
The technique of liver puncture as described by Holtenius (1961) was assessed with regard to its practicability and safety in a preliminary study of 26 cattle and a follow-up study of 108 German black pied cattle. The sample material was smeared, stained and examined by light microscope. All animals with changes of grade 5 had to be slaughtered. Liver puncture is a simple, quick and safe technique which supplies useful information about the various stages of hepatic fatty degeneration in individual cattle. 相似文献
4.
Current German law on animal rights requires protection and appropriate treatment of animals. However, information on breeding and raising swine is incomplete, and comparison studies of alternative housing systems are needed. Therefore, the effects of single and group housing of pregnant sows on piglet production was investigated in the 120-sow herd of the Institute for Animal Breeding and Husbandry of the University of Kiel. Reproductive traits, general health and behaviour studies were evaluated over one year. Type of housing system was found to have no effect on number of piglets born alive or dead or on days open. Daily gain was influenced. Daily gain of single-housed sows increased but without any difference in feed intake. General health was measured by nutritional condition, soiling, callosity, and injuries at time of evaluation. Single-housed sows had more calluses and were more soiled compared with group-housed sows. Injuries occurred more often in group housing, especially when new animals were integrated into the group. However, injuries were not serious. Animal behaviour was recorded on video during one pregnancy period of 60 sows. The housing system effected "sitting" and "lying" behaviour. Behaviour also is influenced by pregnancy in both housing systems. Equal incidences of abnormal behaviour, considered as sham-chewing, were found in both housing systems. 相似文献
5.
6.
7.
Fabricius Fritz Ernst Reinhold Haenel und Bogtherr 《Forstwissenschaftliches Centralblatt》1933,55(21):758-770
Ohne Zusammenfassung 相似文献
8.
9.
Ohne Zusammenfassung 相似文献
10.