全文获取类型
收费全文 | 1234篇 |
免费 | 77篇 |
国内免费 | 141篇 |
专业分类
林业 | 63篇 |
农学 | 85篇 |
基础科学 | 141篇 |
236篇 | |
综合类 | 376篇 |
农作物 | 39篇 |
水产渔业 | 26篇 |
畜牧兽医 | 441篇 |
园艺 | 13篇 |
植物保护 | 32篇 |
出版年
2024年 | 5篇 |
2023年 | 18篇 |
2022年 | 35篇 |
2021年 | 56篇 |
2020年 | 49篇 |
2019年 | 54篇 |
2018年 | 38篇 |
2017年 | 68篇 |
2016年 | 72篇 |
2015年 | 64篇 |
2014年 | 67篇 |
2013年 | 67篇 |
2012年 | 98篇 |
2011年 | 74篇 |
2010年 | 60篇 |
2009年 | 74篇 |
2008年 | 58篇 |
2007年 | 64篇 |
2006年 | 65篇 |
2005年 | 59篇 |
2004年 | 42篇 |
2003年 | 31篇 |
2002年 | 21篇 |
2001年 | 29篇 |
2000年 | 21篇 |
1999年 | 36篇 |
1998年 | 16篇 |
1997年 | 21篇 |
1996年 | 22篇 |
1995年 | 15篇 |
1994年 | 11篇 |
1993年 | 9篇 |
1992年 | 5篇 |
1991年 | 5篇 |
1990年 | 6篇 |
1989年 | 9篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 2篇 |
排序方式: 共有1452条查询结果,搜索用时 15 毫秒
21.
22.
23.
M. Podell H.A. Volk M. Berendt W. Löscher K. Muñana E.E. Patterson S.R. Platt 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2016,30(2):477-490
This report represents a scientific and working clinical consensus statement on seizure management in dogs based on current literature and clinical expertise. The goal was to establish guidelines for a predetermined, concise, and logical sequential approach to chronic seizure management starting with seizure identification and diagnosis (not included in this report), reviewing decision‐making, treatment strategies, focusing on issues related to chronic antiepileptic drug treatment response and monitoring, and guidelines to enhance patient response and quality of life. Ultimately, we hope to provide a foundation for ongoing and future clinical epilepsy research in veterinary medicine. 相似文献
24.
25.
采用柠檬酸法合成出超微W型铁氧体。用XRD、VSM测试其结构和磁性能。试验结果表明,该法在1000℃制得的铁氧体性能优于其他方法制得的铁氧体,控制pH值、水量和柠檬酸的量对铁氧体的结构和磁性能都有一定的影响。 相似文献
26.
Taeymans O Peremans K Saunders JH 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2007,21(4):673-684
This review describes the advantages and disadvantages of radiography, ultrasonography, and nuclear medicine in the 2 most frequent thyroid pathologies of the dog: acquired primary hypothyroidism and thyroid neoplasia. Ultrasonography and scintigraphy remain the 2 most indicated imaging modalities for these thyroid abnormalities. However, as in human medicine, computed tomography and magnetic resonance imaging also have potential indications. This is especially the case in the evaluation of the extent, local invasiveness, and local or distant metastases of thyroid neoplasia. Based on experience with different imaging modalities in people, we suggest future directions in the imaging of the canine thyroid gland. 相似文献
27.
28.
29.
Widely concerns of the influence of the HVDC system on the Three Gorges power station have been shown so far. Based on the understanding of the mechanism of the non-characteristic harmonics introduced by HVDC system, the influence of interharmonics on the shaft of hydro-generator unit is studied. A MATLAB simulation model for the Three Gorges hybrid AC and DC transmission system with considering the effect of generator-unit shaft is established. Through time-domain simulation, the influence of the minor-associated component of interharmonics on the generator-unit shaft is analyzed, which arise from the asynchronous operation of the HVDC system. Also, the complex torque coefficient method in frequency-domain is used to analyze this problem. Same conclusions can be drawn from the results of timedomain and frequency-domain analyses. 相似文献
30.
A new method is introduced to measure the conductivity of brain. This method uses magnetic excitation to induce eddy currents inside the brain matter and measures the magnetic field caused by the induced eddy current. The theoretical basis of this method is analyzed and the measurement system is introduced. The aufhors do the experiment and draw a conclusion that the method provided is feasible. 相似文献