全文获取类型
收费全文 | 12974篇 |
免费 | 695篇 |
国内免费 | 9篇 |
专业分类
林业 | 1557篇 |
农学 | 320篇 |
基础科学 | 53篇 |
2565篇 | |
综合类 | 1737篇 |
农作物 | 399篇 |
水产渔业 | 778篇 |
畜牧兽医 | 5015篇 |
园艺 | 332篇 |
植物保护 | 922篇 |
出版年
2023年 | 94篇 |
2022年 | 114篇 |
2021年 | 230篇 |
2020年 | 230篇 |
2019年 | 237篇 |
2018年 | 366篇 |
2017年 | 330篇 |
2016年 | 344篇 |
2015年 | 304篇 |
2014年 | 350篇 |
2013年 | 645篇 |
2012年 | 790篇 |
2011年 | 949篇 |
2010年 | 472篇 |
2009年 | 413篇 |
2008年 | 781篇 |
2007年 | 847篇 |
2006年 | 764篇 |
2005年 | 712篇 |
2004年 | 670篇 |
2003年 | 658篇 |
2002年 | 613篇 |
2001年 | 262篇 |
2000年 | 230篇 |
1999年 | 173篇 |
1998年 | 93篇 |
1997年 | 90篇 |
1996年 | 91篇 |
1995年 | 129篇 |
1994年 | 95篇 |
1993年 | 73篇 |
1992年 | 67篇 |
1991年 | 60篇 |
1990年 | 61篇 |
1989年 | 66篇 |
1988年 | 66篇 |
1987年 | 44篇 |
1986年 | 61篇 |
1985年 | 69篇 |
1984年 | 51篇 |
1983年 | 51篇 |
1982年 | 37篇 |
1980年 | 53篇 |
1979年 | 39篇 |
1978年 | 27篇 |
1977年 | 40篇 |
1976年 | 29篇 |
1975年 | 24篇 |
1973年 | 32篇 |
1966年 | 26篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
T. Pudert A. Weyrich F. Geburek C. Herden M. Röcken 《Equine Veterinary Education》2021,33(11):e386-e392
Thymoma is a rare condition in horses. This case of a 24-year-old Warmblood gelding that was presented with oedema and signs of vascular congestion of the left forelimb caused by a thoracic mass is described. The diagnostic work-up included blood chemistry, cytology of pleural effusion, ultrasonography, radiography and the visualisation and collection of a tissue sample by thoracoscopy. Finally, post-mortem findings and histopathology revealed thymic epithelial neoplasia with histomorphologic features previously unreported in horses. The unique mixture of spindle-shaped and epithelioid tumour cells in combination with clear features of malignancy suggested the application of the Moran and Suster histological classification system for thymomas in humans (Moran and Suster, 2008, Curr. Treat. Options Oncol., 9, 288), which has not been reported in an equine case before and fits well to the present case. 相似文献
2.
3.
The aerobic bacterial flora of the genital tract was characterized in 15 stud dogs in an 18-month study. The dogs represented 4 breeds and were from 3 kennels. Bacterial samples from the prepuce and semen were collected every month, except in connection with matings, when they were collected weekly (464 samples). The dogs that were included all mated at least once during the study. The mean pregnancy rate, litter size, and pup mortality for the bitches with which they had mated were all within normal limits. The most frequent bacteria isolated from the prepuce and semen were Pasteurella multocida, beta-hemolytic streptococci, and Escherichia coli. There was a tendency for breeds to differ in frequency of the most common bacterial species. Bacterial culture yielded no aerobic growth in 14.2% of the preputial samples and 69.8% of the semen samples. Bacteria were transferred between dog and bitch at mating. In this study of healthy breeding dogs, neither the fertility of the dog nor that of the bitch was affected by the bacteria transferred. 相似文献
4.
5.
B. Götz 《Journal of pest science》1938,14(8):92-93
Ohne Zusammenfassung 相似文献
6.
7.
Revierförfter von Mühlen zu Solitude 《European Journal of Forest Research》1868,12(1):340-342
Ohne Zusammenfassung
Bergleiche Auguftheft diefer Bl?tter, in melchem gleichfalls auf die Wichtigfeit diefes Qegenftandes hingemiefen murde. Die
Red. 相似文献
8.
Michael J. A. Young Arlo W. Fast Paul G. Olin 《Journal of the World Aquaculture Society》1989,20(1):7-11
Chinese catfish ( Clarias fuscus ) were successfully spawned in Hawaii using human chorionic gonadotropin (HCG) at dosage rates of two and four international units (IU) per gram body weight. Fish not injected with HCG did not produce viable eggs. Successful spawns with HCG occurred between May and October. Hatch rates of up to 80% were obtained during June, July, and August for those fish given either a 2 or 4 IU per gram body weight injection of HCG. Fish spawned in either May or October yielded significantly higher hatch rates when injected with 4 rather than 2 IU per gram body weight. Fish held at elevated temperatures (28 to 30 C) prior to the normal spawning season developed significantly larger oocyte diameters, 60 days earlier than fish held under ambient temperature conditions (21.5 to 24 C). Photoperiod manipulation at ambient temperature conditions was associated with earlier oocyte maturation, but photoperiod effects were much less important than temperature. 相似文献
9.
Lactate Kinetics in veterinary Critical Care: A Review 总被引:3,自引:0,他引:3
Michael S. Lagutchik DVM Gregory K. Ogilvie DVM Wayne E. Wingfield MS DVM Timothy B. Hackett DVM MS 《Journal of Veterinary Emergency and Critical Care》1996,6(2):81-95.
Elevation in blood lactate concentration, with or without accompanying metabolic acidosis, is a hallmark finding in patients with circulatory compromise, and is also consistently noted in other conditions affecting critically ill or injured individuals. Little is reported in a veterinary literature regarding lactate measurement in the emergency and critical care setting, despite impressive reports of the clinical usefulness of lactate measurement in people. The purpose of this article is to review lactate kinetics and the clinical utility of lactate measurement. Limitations to lactate evaluation will also be discussed. 相似文献
10.