首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   650篇
  免费   31篇
  国内免费   1篇
林业   38篇
农学   18篇
基础科学   7篇
  62篇
综合类   148篇
农作物   12篇
水产渔业   17篇
畜牧兽医   351篇
园艺   10篇
植物保护   19篇
  2020年   9篇
  2019年   7篇
  2018年   13篇
  2017年   11篇
  2016年   9篇
  2015年   9篇
  2014年   7篇
  2013年   32篇
  2012年   23篇
  2011年   20篇
  2010年   9篇
  2009年   13篇
  2008年   24篇
  2007年   12篇
  2006年   17篇
  2005年   20篇
  2004年   20篇
  2003年   16篇
  2002年   23篇
  2001年   28篇
  2000年   14篇
  1999年   11篇
  1996年   7篇
  1995年   4篇
  1993年   7篇
  1992年   8篇
  1991年   19篇
  1990年   10篇
  1989年   18篇
  1988年   8篇
  1987年   18篇
  1986年   12篇
  1985年   13篇
  1984年   8篇
  1983年   8篇
  1982年   7篇
  1981年   8篇
  1980年   4篇
  1979年   7篇
  1978年   9篇
  1977年   4篇
  1976年   7篇
  1974年   7篇
  1973年   10篇
  1972年   7篇
  1971年   9篇
  1970年   7篇
  1969年   4篇
  1895年   6篇
  1886年   5篇
排序方式: 共有682条查询结果,搜索用时 15 毫秒
1.
Seven of 30 canaries in an aviary in New Zealand developed ophthalmic problems. Clinically, 5 birds had unilateral and 2 birds had bilateral lesions characterized by conjunctivitis, crusty exudates on eyelids, and collapse of the eyeball. Microscopic lesions in 12 of 14 eyes examined included inflammation of the choroid and retina, with osseous replacement of the globe in some. Numerous Toxoplasma gondii tachyzoites were seen in the detached retina and vitreous humor of acutely affected birds. The diagnosis of toxoplasmosis was confirmed by immunohistochemical staining with T gondii antiserum. Affected birds had encephalitis, and T gondii was localized in the brains of these by immunohistochemical examination and by use of bioassays in mice. Toxoplasmosis should be considered in differential diagnosis of ophthalmitis in canaries.  相似文献   
2.
Ketoconazole therapy in a dog with systemic cryptococcosis   总被引:1,自引:0,他引:1  
A 2-year-old dog had bilateral chorioretinitis and a cough. Systemic cryptococcosis was diagnosed by evaluating a trans-tracheal aspirate and a cryptococcal latex-particle agglutination antigen titer. Clinical remission was achieved with ketoconazole administration, an imidazole antifungal agent. Serial antigen titers were used to monitor treatment, which was continued for 12 months. Ketoconazole therapy was well tolerated by the dog.  相似文献   
3.
Thirty eight newly weaned hinds were randomly allocated to one of two equal groups. One group received ivermectin, the other, oxfendazole at dose rates of 0.2 mg/kg and 4.5 mg/kg, respectively. All deer were drenched four times and were grazed on pasture. Both anthelmintics reduced D. viviparus faecal larval counts to low levels 20 days after dosing, but the mean larval output and the proportion of deer shedding D. viviparus larvae at 27 and 33 days after treatment, were significantly lower in the ivermectin treated group. There was no significant difference in weight gain between the two groups throughout the trial. This study suggests that ivermectin prevents reinfection with D. viviparus for approximately 14 days longer than oxfendazole.  相似文献   
4.
A yearling Rambouillet ram with an asymmetrical scrotum was examined for potential breeding soundness prior to use in a synchronized mating program in a purebred flock of 20 ewes. Initial sperm cell evaluation revealed 78% knobbed acrosomes associated with few other abnormalities of the head and midpiece. Use of the ram resulted in no conception in one group of ten synchronized ewes. One month later, the proportion of sperm cells with knobbed acrosomes was 80%.  相似文献   
5.
Cysts found in the liver of a horse which had never been out of New Zealand were used to infect two dogs which were slaughtered 35 days after infection. Large numbers of Echinococcus granulosus were recovered. These cestodes were compared with mature dog-sheep cestodes, using light and scanning electron microscopy and identified as the dog-horse strain of E.granulosus.  相似文献   
6.
7.
The temporary dentitions of 18 to 39-week-old lambs with a very light or a very heavy parasite burden are compared. The heavily parasitised lambs developed longer temporary incisors which tended to protrude further forward in relation to the upper dental pad. They showed absolute hypocalcaemia and hypoalbuminaemia and relative hypophosphataemia and hypoproteinaemia and in the alveolar bone of the mandible there was a reduction in ash and matrix densities and matrix mineralisation. The incisor protrusion and lengthening may have been a consequence of the loss of supporting bone, but inappetance was likely to have been a factor contributing to the lengthening.  相似文献   
8.
9.
10.
Cystic lymphangiomas are rare malformations of the lymphatics that result in the formation of a cystic mass. Where multiple cysts are seen, the condition is termed cystic lymphangiomatosis. This case describes the diagnosis and unique management of cystic lymphangiomatosis in a 10‐day‐old Thoroughbred foal. Ultrasonography, histopathology and laparoscopy were essential for diagnosis and appreciation of the extent of disease. Ultimately, the cystic lymphangiomatosis was so extensive in this foal that complete surgical excision was considered impossible and the presence of adhesions within the abdomen indicated a very poor long‐term prognosis; the owners elected for euthanasia at age 14 weeks. Although rare, lymphangioma and lymphangiomatosis should be considered as a differential diagnosis for an intra‐abdominal mass in a young horse.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号