全文获取类型
收费全文 | 1715篇 |
免费 | 126篇 |
国内免费 | 7篇 |
专业分类
林业 | 125篇 |
农学 | 47篇 |
基础科学 | 13篇 |
362篇 | |
综合类 | 190篇 |
农作物 | 67篇 |
水产渔业 | 136篇 |
畜牧兽医 | 681篇 |
园艺 | 45篇 |
植物保护 | 182篇 |
出版年
2023年 | 13篇 |
2022年 | 13篇 |
2021年 | 21篇 |
2020年 | 41篇 |
2019年 | 66篇 |
2018年 | 35篇 |
2017年 | 46篇 |
2016年 | 52篇 |
2015年 | 52篇 |
2014年 | 55篇 |
2013年 | 82篇 |
2012年 | 122篇 |
2011年 | 137篇 |
2010年 | 91篇 |
2009年 | 95篇 |
2008年 | 122篇 |
2007年 | 96篇 |
2006年 | 89篇 |
2005年 | 81篇 |
2004年 | 87篇 |
2003年 | 91篇 |
2002年 | 91篇 |
2001年 | 26篇 |
2000年 | 20篇 |
1999年 | 16篇 |
1998年 | 8篇 |
1997年 | 17篇 |
1996年 | 11篇 |
1995年 | 9篇 |
1994年 | 9篇 |
1993年 | 4篇 |
1992年 | 8篇 |
1991年 | 12篇 |
1990年 | 8篇 |
1989年 | 10篇 |
1988年 | 5篇 |
1987年 | 7篇 |
1986年 | 10篇 |
1985年 | 8篇 |
1984年 | 6篇 |
1983年 | 7篇 |
1982年 | 8篇 |
1981年 | 5篇 |
1980年 | 5篇 |
1978年 | 7篇 |
1977年 | 6篇 |
1976年 | 5篇 |
1974年 | 4篇 |
1967年 | 3篇 |
1958年 | 3篇 |
排序方式: 共有1848条查询结果,搜索用时 15 毫秒
1.
Luc Van Ham Marc Vandevelde Miek Desmidt Mulenda Tshamala Luc De Schaepdrijver Daniel Mattheeuws 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》1994,8(4):290-292
A central axonopathy in 2 male and 1 female Scottish Terrier puppies from 3 different but related litters is reported. Clinical signs consisting of severe whole-body tremors and ataxia were first detected at the age of 10 to 12 weeks. They worsened with activity and excitement and diminished during rest or sleep. Two dogs also had paraparesis. In 1 dog the neurological deficits progressed over several months. Neuropathological examination revealed widespread axonal changes, vacuolation, and gliosis in the white matter of the central nervous system. 相似文献
2.
Senior Care Guidelines Task Force AAHA Epstein M Kuehn NF Landsberg G Lascelles BD Marks SL Schaedler JM Tuzio H 《Journal of the American Animal Hospital Association》2005,41(2):81-91
This paper provides a working framework for enhancing the well-being of senior pet dogs and cats. Approaches to screening the medical status of senior pets are described in detail, with particular emphasis on establishing baseline data in healthy animals, the testing of clinically ill animals, and assessing senior pets prior to anesthesia and surgery. The management of pain and distress and the application of hospice and palliative care are addressed. Advice on ways to approach euthanasia and dealing with end-of-life issues is also provided. 相似文献
3.
4.
5.
Olivier M. Lepage DMV MSc Renée Léveillé DMV Luc Breton DMV MSc Marcel Marcoux DMV MSc 《Veterinary radiology & ultrasound》1995,36(5):384-386
An 11-month-old Thoroughbred colt was presented with a hard swelling at the proximal third of the right 4th metatarsal bone. A medial dislocation of the deep digital flexor tendon ( flexor digitorum profundus ) was also observed on the same leg. On the plantaroproximal-plantarodistal projection of the calcaneus, there was flattening and shortening of the sustentaculum tali. The smooth bony proliferation at the proximal third of the right 4th metatarus was compatible with a chronic splint bone fracture. This report describes a medial deep digital flexor dislocation associated with hypoplasia of the sustentaculum tali . 相似文献
6.
7.
In a report describing life ending fractures (255 horses) from the Livestock Disease Diagnostic Center, Kentucky (1993 and 1994), 32 foals had rib fractures. The purpose of our study was to examine the incidence of rib fractures in newborn foals on a Thoroughbred studfarm by physical and radiographic examination, to determine factors which may contribute to the problem and to document any clinical consequences. All foals (263) included were examined within 3 days of birth. The thoracic cage was palpated externally for abnormalities and all foals were placed in dorsal recumbency to evaluate thoracic cage symmetry. Radiographs were used to diagnose foals with thoracic cage asymmetry (TCA) and rib fracture (RF). A diagnosis of costochondral dislocation (CD) was made when no radiographic evidence of fracture was present but there was severe TCA. Fifty-five foals (20.1%) had TCA (9 RF). One to 5 ribs were fractured on 9 of 40 radiographic studies. No consequences of the thoracic trauma was detected clinically, radiographically or ultrasonographically in this group of foals or at a 2- and 4-week follow-up examination. The percentage of foals with a history of abnormal parturition was higher in the TCA foals (15%) compared to the normal foals (6.8%). There were more primiparous dams in the TCA group than in the normal foal group. Fillies (56.6%) had a higher incidence of birth trauma than colts (43.4%). This study demonstrates that thoracic trauma is often present in newborn foals and may not always be of clinical significance. Dystocia foals and foals from primiparous mares should be considered high risk for thoracic trauma. 相似文献
8.
Lydia M Attard Ramon A Carreno Jean A Paré Andrew S Peregrine Christopher J Dutton Thomas R Mason 《Journal of zoo and wildlife medicine》2008,39(3):488-492
A die-off occurred in a captive colony of blue-winged grasshoppers (Tropidacris collaris) at the Toronto Zoo. One fourth of the colony died within a year due to infection with worms initially mistaken for nematomorphs but later identified as nematodes belonging to the Mermithidae, genus Mermis. Mortality persisted and the grasshopper population dwindled over the following years. Mermithid larvae developed in the hemocoel of the insects until they eventually emerged from a hollowed-out exoskeleton. Circumstantial evidence suggests that the parasites were introduced with raspberry browse that was grown on site and contaminated with mermithid eggs. 相似文献
9.
Wolf KN Harms CA Beasley JF 《Journal of the American Veterinary Medical Association》2008,233(3):470-475
OBJECTIVE: To compare blood biochemical values obtained from a handheld analyzer, 2 tabletop analyzers, and 2 diagnostic laboratories by use of replicate samples of sea turtle blood. DESIGN: Validation study. ANIMALS: 22 captive juvenile sea turtles. PROCEDURES: Sea turtles (18 loggerhead turtles [Caretta caretta], 3 green turtles [Chelonia mydas], and 1 Kemp's ridley turtle [Lepidochelys kempii]) were manually restrained, and a single blood sample was obtained from each turtle and divided for analysis by use of the 5 analyzers. Hematocrit and concentrations or activities of aspartate aminotransferase, creatine kinase, glucose, total protein, albumin, BUN, uric acid, P, Ca, K, Na, Cl, lactate dehydrogenase, and alkaline phosphatase were determined. Median values for each analyte were compared among the analyzers. RESULTS: Significant differences were found among the analyzers for most values; however, data obtained from the 2 diagnostic laboratories were similar for all analytes. The magnitude of difference between the diagnostic laboratories and in-house units was > or = 10% for 10 of the 15 analytes. CONCLUSIONS AND CLINICAL RELEVANCE: Variance in the results could be attributed in part to differences in analyzer methodology. It is important to identify the specific methodology used when reporting and interpreting biochemical data. Depending on the variable and specific case, this magnitude of difference could conceivably influence patient management. 相似文献
10.