全文获取类型
收费全文 | 342篇 |
免费 | 25篇 |
专业分类
林业 | 21篇 |
农学 | 4篇 |
基础科学 | 1篇 |
76篇 | |
综合类 | 31篇 |
农作物 | 12篇 |
水产渔业 | 35篇 |
畜牧兽医 | 162篇 |
园艺 | 3篇 |
植物保护 | 22篇 |
出版年
2024年 | 1篇 |
2023年 | 11篇 |
2022年 | 4篇 |
2021年 | 10篇 |
2020年 | 16篇 |
2019年 | 27篇 |
2018年 | 15篇 |
2017年 | 7篇 |
2016年 | 17篇 |
2015年 | 13篇 |
2014年 | 13篇 |
2013年 | 13篇 |
2012年 | 32篇 |
2011年 | 34篇 |
2010年 | 11篇 |
2009年 | 9篇 |
2008年 | 27篇 |
2007年 | 18篇 |
2006年 | 22篇 |
2005年 | 14篇 |
2004年 | 13篇 |
2003年 | 10篇 |
2002年 | 12篇 |
2001年 | 1篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1992年 | 2篇 |
1990年 | 1篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1979年 | 2篇 |
1974年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有367条查询结果,搜索用时 31 毫秒
71.
Can the protozoan parasite Bonamia ostreae infect larvae of flat oysters Ostrea edulis? 总被引:1,自引:0,他引:1
Arzul I Langlade A Chollet B Robert M Ferrand S Omnes E Lerond S Couraleau Y Joly JP François C Garcia C 《Veterinary parasitology》2011,179(1-3):69-76
Bonamia ostreae is an intracellular protistan parasite affecting flat oysters Ostrea edulis. It can be detected in juveniles but mortalities mainly affect oysters which are more than 2 years old. The parasite is usually observed inside haemocytes and sometimes free, notably in gill epithelia suggesting a parasite release through this organ. However, the infective form and ways of entry and release remain undetermined. Flat oysters incubate their larvae in their pallial cavity for 8-10 days before releasing them into the water column. Flat oysters in Bay of Quiberon in South Brittany (France) are known to be infected with B. ostreae since 1979 and is the most important area in France for O. edulis spat collection. Flat oysters incubating larvae were sampled in this area during summertime between 2007 and 2009. Both adults and larvae were preserved and assayed by PCR and in situ hybridisation (ISH). PCR tests revealed the presence of parasite DNA in some adults and larvae. Specific labelling could be detected by ISH in gills, digestive system, gonad and mantle in adults and in the epithelium surrounding the visceral cavity of some larvae. Our results demonstrate that larvae can be infected with B. ostreae. Larvae might thus contribute to the spread of the parasite during their planktonic life. In addition, their transfer for aquaculture purpose should be controlled especially when they are exported from infected zones. 相似文献
72.
Heidrun Gehlen Sophie Twickel Sabita Stöckle Corinna Weber Claus P. Bartmann 《Journal of animal physiology and animal nutrition》2020,104(2):679-689
Pituitary pars intermedia dysfunction is the most prevalent endocrine disease in horses. Although donkeys and mules may also be affected, only a few data have been published. Reference values for diagnostic parameters, such as adrenocorticotropic hormone (ACTH), are especially scarce or even lacking. Therefore, in the present study, available data from the literature have been verified and completed to facilitate a reliable diagnosis. Clinical inspections and haematological and biochemical examinations were carried out four times in a three-month interval (February to November) in 44 donkeys and 31 mules. Data from clinically healthy animals were used as an orientation. Plasma ACTH concentrations showed seasonal changes in both animal groups. However, it was generally higher in donkeys than mules. Although blood glucose (EDTA plasma) showed no difference between groups, serum insulin concentrations were consistently higher in donkeys. Serum fructosamine levels were slightly higher in mules, whereas, in some cases, serum triglyceride levels were considerably higher in donkeys. Serum gamma-glutamyltransferase showed a striking peak in mules in August, whereas the remaining gamma-glutamyltransferase values were lower compared to donkeys. By comparing donkeys and mules, the present work reveals differences in various blood parameters which should be considered for diagnoses and future studies. 相似文献
73.
74.
75.
76.
Estimating the onset of cambial activity in Scots pine in northern Finland by means of the heat-sum approach 总被引:1,自引:0,他引:1
We estimated the date of onset (Date(est)) of cambial activity by the pinning method in Scots pine (Pinus sylvestris L.) trees at Vanttauskoski (Site 1) and Laanila (Site 2) near the latitudinal limit of Scots pine in northern Finland. In each year and at each site, observations were made on a different set of five trees. The estimated dates of onset of cambial activity were compared with the corresponding heat sums, calculated in degree-days according to two models. Within years, Date(est) varied among trees by up to 15 days at Site 1 and up to 13 days at Site 2. Among years, mean Date(est) varied by 15.3 days at Site 1 and 12.0 days at Site 2. The overall mean Date(est) differed between sites by 6 days (June 5 at Site 1 and June 11 at Site 2). Among all trees in all years, the mean number of degree days (d.d.) calculated from mean daily temperature above a threshold of 5 degrees C before Date(est) ranged from 68.7 to 135 d.d. at Site 1 and from 37.4 to 154.7 d.d. at Site 2. Among years, the mean heat sum before Date(est )ranged from 94 to 112.5 d.d. at Site 1 and from 61.4 to 136 d.d. at Site 2. Variation among years in heat sum before Date(est) at Site 2 was highly significant, indicating that one or more factors other than, or in addition to, heat sum determines the onset of cambial activity in Scots pine. Similar results were obtained when heat sum was computed from the area between the sine wave generated by daily maximum and minimum temperature and the threshold temperature. 相似文献
77.
78.
79.
80.