全文获取类型
收费全文 | 78篇 |
免费 | 14篇 |
专业分类
综合类 | 12篇 |
农作物 | 2篇 |
水产渔业 | 1篇 |
畜牧兽医 | 75篇 |
植物保护 | 2篇 |
出版年
2023年 | 1篇 |
2020年 | 1篇 |
2019年 | 2篇 |
2018年 | 2篇 |
2017年 | 4篇 |
2016年 | 1篇 |
2015年 | 7篇 |
2014年 | 1篇 |
2013年 | 13篇 |
2011年 | 1篇 |
2010年 | 6篇 |
2009年 | 5篇 |
2007年 | 5篇 |
2006年 | 1篇 |
2005年 | 4篇 |
2004年 | 3篇 |
2003年 | 1篇 |
2002年 | 1篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 6篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1984年 | 1篇 |
1969年 | 1篇 |
1959年 | 1篇 |
排序方式: 共有92条查询结果,搜索用时 15 毫秒
91.
Ulrich Nitsch 《Agriculture and Human Values》1988,5(4):50-56
Traditionally, the Swedish Agricultural Extension Service has delivered technical information to farmers with the aim of increasing productivity and efficiency in farming. Present problems with overproduction of food and the negative social and environmental consequences of present farm practices has brought this traditional mission in question. In a situation of budgetary constraints it has been suggested that the funding of the governmental Agricultural Extension Service should be cut down or even discontinued altogether The article argues that this would be a mistake. The various negative consequences of modern agriculture indicate that we are far from an ideal mode of agricultural production. Instead, public opinion and new guidelines for agricultural and environmental policies call for substantial changes in Swedish agriculture with respect to pollution, preservation of non-renewable resources, maintaining an open rural landscape, ethical aspects of animal production, rural development etc. This reorientation of Swedish agriculture presumes that decision-makers, farmers, and the public at large get an opportunity to learn more about the complexities of agricultural production. In contributing to this learning process the Agricultural Extension Service would have an important mission. To be able to fulfill this mission, extension professionals must be provided an opportunity to learn a broader concept of productivity and efficiency in agriculture, for instance, how to extend cost-benefit analyses and technical criteria of efficiency to include social, environmental, and ethical aspects. Our present extension staff has not received adequate training for this task. It is suggested that all agricultural colleges need to create departments of Rural Sociology and Agricultural Humanities to provide agricultural students and professionals an opportunity to develop a better understanding of agriculture and make them prepared to take on the challenges and responsibilities they confront in developing our future agriculture. 相似文献
92.
LFC Brito JB Engiles RM Turner LM Getman A Ebling 《Reproduction in domestic animals》2009,44(5):846-851
An 18-year-old Friesian stallion was examined approximately one week after reportedly presenting scrotal swelling due to torsion of the spermatic cords. Upon presentation no scrotal swelling was noted, the testes were normally oriented, and no abnormalities of the spermatic cords were noted. However, both testes were smaller than expected for a mature stallion and deep palpation revealed that the consistency of the testes was nodular. Ultrasonographic evaluation of the testes revealed diffuse heterogeneous parenchyma with multiple hypoechoic nodular areas. Grossly, the testicular parenchyma was effaced by multiple gray-tan nodules of varying consistency interspersed with gray-white bands of tissue. Microscopic analysis revealed multiple pleomorphic neoplastic foci disseminated throughout both testes. Histological and immunohistochemical features were atypical and consistent with the diagnosis of bilateral testicular mixed germ cell-sex cord stromal tumours. Bilateral testicular tumours and testicular mixed cell tumours are extremely rare in stallions and this is the first report of bilateral testicular mixed germ cell-sex cord-stromal tumours in a stallion. Our findings indicate that certain ultrasonographic characteristics are suggestive of testicular tumour and that immunohistochemistry markers can be used to better characterize testicular neoplasms in stallions. 相似文献