全文获取类型
收费全文 | 25408篇 |
免费 | 791篇 |
国内免费 | 9篇 |
专业分类
林业 | 877篇 |
农学 | 752篇 |
基础科学 | 160篇 |
3625篇 | |
综合类 | 3530篇 |
农作物 | 911篇 |
水产渔业 | 1349篇 |
畜牧兽医 | 13179篇 |
园艺 | 268篇 |
植物保护 | 1557篇 |
出版年
2019年 | 257篇 |
2018年 | 415篇 |
2017年 | 508篇 |
2016年 | 472篇 |
2015年 | 337篇 |
2014年 | 457篇 |
2013年 | 959篇 |
2012年 | 794篇 |
2011年 | 949篇 |
2010年 | 686篇 |
2009年 | 669篇 |
2008年 | 965篇 |
2007年 | 916篇 |
2006年 | 808篇 |
2005年 | 735篇 |
2004年 | 643篇 |
2003年 | 705篇 |
2002年 | 605篇 |
2001年 | 803篇 |
2000年 | 799篇 |
1999年 | 633篇 |
1998年 | 274篇 |
1997年 | 282篇 |
1995年 | 259篇 |
1994年 | 227篇 |
1993年 | 232篇 |
1992年 | 424篇 |
1991年 | 516篇 |
1990年 | 434篇 |
1989年 | 411篇 |
1988年 | 400篇 |
1987年 | 409篇 |
1986年 | 363篇 |
1985年 | 388篇 |
1984年 | 339篇 |
1983年 | 287篇 |
1982年 | 243篇 |
1979年 | 383篇 |
1978年 | 289篇 |
1977年 | 290篇 |
1976年 | 299篇 |
1975年 | 317篇 |
1974年 | 332篇 |
1973年 | 302篇 |
1972年 | 290篇 |
1971年 | 245篇 |
1969年 | 289篇 |
1968年 | 269篇 |
1967年 | 326篇 |
1966年 | 304篇 |
排序方式: 共有10000条查询结果,搜索用时 125 毫秒
41.
Two miniature Shetland ponies showing clinical signs of Digitalis purpurea (foxglove) poisoning were examined. One animal died shortly afterwards, but the second was treated successfully with the anti-arrhythmic agent, phenytoin, and was discharged after 16 days. 相似文献
42.
43.
M Hertel U Kersten R Mischke I Nolte 《Berliner und Münchener tier?rztliche Wochenschrift》1999,112(6-7):239-242
Based on results of holter ecg recordings taken from 38 dogs the computerized analyses system turned out as method not exactly valuing the frequency and sensitivity of arrhythmias. Despite there was a significant correlation between the computerized and visual arrhythmia analysis for ventricular respectively supraventricular premature beats, in individual cases there was an important aberration between the particular values. 相似文献
44.
45.
The feline one-way mixed leukocyte reaction (MLR) was accomplished by a microtechnique assay using gradient purified mononuclear leukocytes from the peripheral blood of specific-pathogen-free (SPF) cats. An eight day assay was required with an appropriate serum supplement of rabbit or cat serum and obtainable cell concentrations of 1×105 mononuclear cells per well of each responder and stimulator population. This assay was devised as an correlate of cell-mediated immunity and to demonstrate that feline histocompatibility differences can be detected in culture. 相似文献
46.
47.
Klejbor I Luczyńska A Ludkiewicz B Domaradzka-Pytel B Moryś J 《Polish journal of veterinary sciences》2003,6(3):201-207
The thalamic nuclei with their defined set of input-output connections are the primary channel for information flow to the cerebral cortex. Several data suggest that neurons of that area are involved in the response to various aversive stimulations. However the pattern of activation seems to depend on the stress model as well as the stage of maturation. In the present study we would like to check which nuclei of the thalamus show expression of c-fos in the response to the "open field test", and how this response pattern changes during the maturation process. 30 rats of age ranged from P0 to P120 (P-postnatal day) were studied. The experimental group was exposed to the "open field test" for 10 minutes. After perfusion and fixation, brains were cut and stained for c-fos with immunohistochemical method. Our results showed that during development the pattern of c-fos activity in the thalamic nuclei after stress stimulation undergoes significant changes. Distinct c-fos expression was observed in the paraventricular nucleus, intergeniculate leaflet and ventral lateral geniculate nucleus. These findings suggest that these nuclei may play a direct role in the stress reaction involved in the response to the "open field test". 相似文献
48.
The department of National Parks and Protection of Wild Nature sent five (two males, three females) adult long-legged buzzards for investigation of their deaths to Ankara University Veterinary Faculty. Facial bones of buzzards were evaluated. Distinguishing facial features such as strong os premaxillare, cavum nasale filled with spider webbing-like structures, prominent os prefrontalis and processes, H-shaped paraglossum were determined. In this study, we investigated the anatomic properties of facial bones in long-legged buzzard. We also aimed to identify the data using these bones in order to separate different bird species. 相似文献
49.
50.