全文获取类型
收费全文 | 80931篇 |
免费 | 4684篇 |
国内免费 | 39篇 |
专业分类
林业 | 4133篇 |
农学 | 2892篇 |
基础科学 | 520篇 |
10915篇 | |
综合类 | 11787篇 |
农作物 | 2996篇 |
水产渔业 | 4560篇 |
畜牧兽医 | 41016篇 |
园艺 | 1086篇 |
植物保护 | 5749篇 |
出版年
2019年 | 716篇 |
2018年 | 1463篇 |
2017年 | 1583篇 |
2016年 | 1502篇 |
2015年 | 1222篇 |
2014年 | 1538篇 |
2013年 | 3242篇 |
2012年 | 2780篇 |
2011年 | 3074篇 |
2010年 | 2026篇 |
2009年 | 2084篇 |
2008年 | 3093篇 |
2007年 | 2834篇 |
2006年 | 2723篇 |
2005年 | 2517篇 |
2004年 | 2545篇 |
2003年 | 2494篇 |
2002年 | 2307篇 |
2001年 | 2571篇 |
2000年 | 2569篇 |
1999年 | 2115篇 |
1998年 | 957篇 |
1997年 | 861篇 |
1996年 | 828篇 |
1995年 | 893篇 |
1994年 | 870篇 |
1993年 | 791篇 |
1992年 | 1631篇 |
1991年 | 1637篇 |
1990年 | 1747篇 |
1989年 | 1614篇 |
1988年 | 1554篇 |
1987年 | 1444篇 |
1986年 | 1477篇 |
1985年 | 1425篇 |
1984年 | 1196篇 |
1983年 | 1087篇 |
1982年 | 671篇 |
1979年 | 1100篇 |
1978年 | 876篇 |
1977年 | 784篇 |
1976年 | 724篇 |
1975年 | 761篇 |
1974年 | 860篇 |
1973年 | 894篇 |
1972年 | 890篇 |
1971年 | 828篇 |
1970年 | 757篇 |
1969年 | 776篇 |
1967年 | 684篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
M. Manou J. Milgram P. Kelly S. Hoey K. Kenny S. Warde B. Kirby 《The Journal of small animal practice》2021,62(10):924-928
A 7-year-old male neutered domestic shorthair outdoor cat was referred for chronic left forelimb lameness, which had been treated with intra-articular injections of triamcinolone acetonide. A soft tissue swelling around the elbow joint, extending from the distal humerus to the proximal ulna, was surgically explored and biopsy samples obtained. Mycobacterium bovis was cultured from samples from the soft tissue and bone. The mycobacteria from the media were killed and the DNA extracted and tested on a multiplex real-time PCR for the absence of specific genes and the presence of mycobacterial genus markers. The PCR revealed bacillus Calmette-Guérin Danish Strain 1331; this was also isolated from the prescapular lymph node, muscle and bone, obtained at post mortem examination. Badgers had been vaccinated with the bacillus Calmette-Guérin vaccine SSI (Statens Serum Institute) in the area where the cat lived, in the spring and autumn of the previous year. To the authors' knowledge, this is the first report of infection with M. bovis bacillus Calmette-Guérin Danish Strain 1331 in a domestic cat, potentially associated with annual vaccination of badgers in the proximity of the cat's home. 相似文献
993.
994.
Josephine A. Dornbusch Laura E. Selmic Pin‐Chieh Huang Jonathan P. Samuelson Eric M. McLaughlin Vincent A. Wavreille Jessica A. Ogden Brittany Abrams Alex Kalamaras Eric Green Eric T. Hostnik Lincoln Every Jason A. Fuerst Ryan Jennings Christopher Premanandan Joshua N. Lorbach Sarah C. Linn Aneesh Alex Janet E. Sorrells Lingxiao Yang Stephen A. Boppart 《Veterinary surgery : VS》2021,50(1):111-120
995.
996.
Julia Belotto Guaraná Alois Foltran Müller Ricardo de Francisco Strefezzi Fabrício Singaretti Oliveira Luciana Cristina Machado Carlos Eduardo Ambrósio Renata Gebara Sampaio Dória Silvio Henrique de Freitas 《Anatomia, histologia, embryologia》2021,50(6):996-1006
The use of live animals for educational purposes is an old practice that is still employed in teaching and research institutions. However, there are several objections to this practice, whether for ethical or humanitarian reasons. Surgical techniques teaching using anatomical pieces and/or preserved cadavers promotes greater learning efficiency, provides exercise repetition and increases the confidence and satisfaction of the students when compared to the use of live animals. The current work aimed to analyse the feasibility of using fresh swine urinary bladder and small intestines (jejunum), obtained from slaughterhouses, fixed in 99.8% ethyl alcohol (EA) and preserved in sodium chloride hypersaturated solution (SCHS) at 30%, for 7, 14 and 21 days, as an alternative method for surgical skills training (SST). Swine viscera, fixed in EA and preserved in SCHS, presented a realistic appearance, absence of odour and maintained the viable morphological characteristics during the performance of the operative techniques. Preservation solutions had low cost, were easy to acquire and did not offers risks to human health. Therefore, urinary bladders and small intestines fixed in 99.8% EA for 30 days and maintained in 30% SCHS at different periods were demonstrated as a good viable option as a preservation method for surgical skills training. 相似文献
997.
Billy P. R. Dries Ilse Jonkers Wim Van Den Broeck Benedicte Vanwanseele Lieve DeRycke Walter Dingemanse Jos Vander Sloten Henri Van Bree Ingrid Gielen 《Anatomia, histologia, embryologia》2021,50(3):637-644
In contrast to other mammals, the large variation in dog sizes is not accompanied by any significant genetic re-organization. In order to study the relationship between body mass, limb length and the functional anatomical muscle parameters of the canine hind limb, a large dataset comprising of muscle masses, optimal muscle fibre lengths and physiological cross-sectional area's (PCSA) were acquired for twenty-five muscles in ten dogs of sizes varying between 20 kg and 52 kg. The potential of body mass and limb length for reliably scaling individual muscle masses, optimal muscle fibre lengths and PCSA's were examined. For the majority of the muscles of the canine hind limb, neither body mass nor limb length were reliable scaling parameter for either muscle masses, PCSA's and optimal fibre length. These results indicate the need of a breed-specific approach to musculoskeletal modelling in future canine musculoskeletal research. 相似文献
998.
İsmail Hakkı Nur William Pérez Horst Erich König 《Anatomia, histologia, embryologia》2021,50(3):658-667
This study aims to reveal the morphological properties of facial nerve and the middle ear in Van cats. Study material was composed of 6 female Van cats. Dissections were performed under a Zoom Stereo Microscope. There was no plexus buccalis in Van cats. The chorda tympani was observed to pass through an opening in the tympanic cavity, emerge through a small opening just behind the retroarticular process, and join the lingual nerve. A rounded anatomical formation with a size of 2.75 ± 0.3 mm was found to be located within the mastoid process of the temporal bone between the facial nerve and the auricular branch of the vagus nerve. The stapes nerve was not present. The geniculate ganglion was very prominent and about 1.00 mm high. The deep petrosal nerve was observed to emerge from the plexus tympanicus. The bulla tympanica was 18.96 ± 0.10 mm long, 13.03 ± 0.20 mm wide and 13.16 ± 0.20 mm high. After leaving the mandibular nerve, the n.tensoris tympani coursed caudally around the a.maxillaris, formed an ansa, entered the tympanic cavity through the canalis musculotubarius and reached an end in the m. tensor tympani. Due to the scarcity of studies on the middle ears of Van cats, it is thought that this study will fill a gap in the field of veterinary anatomy. 相似文献
999.