全文获取类型
收费全文 | 997篇 |
免费 | 4篇 |
专业分类
林业 | 84篇 |
农学 | 2篇 |
149篇 | |
综合类 | 251篇 |
农作物 | 19篇 |
水产渔业 | 7篇 |
畜牧兽医 | 457篇 |
园艺 | 1篇 |
植物保护 | 31篇 |
出版年
2021年 | 2篇 |
2015年 | 2篇 |
2013年 | 4篇 |
2012年 | 92篇 |
2011年 | 90篇 |
2010年 | 23篇 |
2009年 | 8篇 |
2008年 | 89篇 |
2007年 | 80篇 |
2006年 | 72篇 |
2005年 | 77篇 |
2004年 | 60篇 |
2003年 | 62篇 |
2002年 | 56篇 |
2001年 | 40篇 |
2000年 | 65篇 |
1999年 | 26篇 |
1998年 | 10篇 |
1997年 | 9篇 |
1996年 | 3篇 |
1995年 | 13篇 |
1994年 | 12篇 |
1993年 | 6篇 |
1992年 | 3篇 |
1991年 | 5篇 |
1990年 | 3篇 |
1989年 | 10篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1980年 | 2篇 |
1979年 | 4篇 |
1978年 | 2篇 |
1973年 | 2篇 |
1954年 | 7篇 |
1938年 | 2篇 |
1936年 | 3篇 |
1934年 | 2篇 |
1933年 | 2篇 |
1932年 | 3篇 |
1929年 | 2篇 |
1912年 | 1篇 |
1911年 | 1篇 |
1906年 | 2篇 |
1905年 | 1篇 |
1904年 | 1篇 |
1899年 | 1篇 |
1886年 | 1篇 |
1881年 | 1篇 |
排序方式: 共有1001条查询结果,搜索用时 15 毫秒
1.
马鹿(Cervus elaphus)属偶蹄目鹿科的的草食性的反刍哺乳动物,食性广,适应性强,对环境条件要求不严格;有较强的避敌等自身防卫能力;可塑性强.特别是马鹿耐粗饲、耐粗牧、抗病性强,与其它家畜的生态位重叠少等特点,倍受畜牧界的关注,养鹿业也将成为本世纪畜牧业发展的热点,其产品具有很高的药用、肉用价值和保健等作用,市场前景广阔.鹿场的规划是马鹿人工养殖的基础,科学合理地规划能够节省开支,以较少的投入获取较大的经济效益;能够有效地管理鹿群,充分发挥鹿群的生产性能;能够合理地安排职工生活和生产活动,激发职工的主人翁精神,实现以人为本的经营和管理理念,促进鹿场管理的现代化. 相似文献
2.
4.
5.
This paper examines the views of members of the veterinary profession towards the change in orientation of professional practice that is occurring. It contrasts the values of veterinarians with those of doctors, dentists, lawyers and accountants. Particular attention is given to the areas of business efficiency, competition and advertising. Data was derived from self-completion questionnaires containing 40 Likert scales which were mailed to 300 members of each of the five professions. 相似文献
6.
7.
Hill D Correa MT Stevens JB 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》1994,23(3):73-75
Azostix-reagent-tests(R) strips (Ames, Miles, Inc., Diagnostic Division, Elkhart, IN) were used to measure blood urea nitrogen values in blood samples from 125 dogs and cats at the North Carolina State University, College of Veterinary Medicine. Results of the tests were compared with standard serum urea nitrogen results. Sensitivity, specificity, and negative predictive values were high (86.4, 90.3, and 96.5%, respectively). Positive predictive value was low, 65.5% of the dogs and cats with elevated blood urea nitrogen values were correctly classified as abnormal The test performs well when the prevalence of abnormal values is near 50%. 相似文献
8.
9.
Savini G Ronchi GF Leone A Ciarelli A Migliaccio P Franchi P Mercante MT Pini A 《Veterinary microbiology》2007,124(1-2):140-146
Because no suitable products are at the moment available to safely control the spread of BTV-16 in Europe, an inactivated vaccine was produced from the reference field isolate of bluetongue virus serotype 16. One group of six sheep was vaccinated subcutaneously with the inactivated vaccine twice, on days 0 and 28, whereas a second group of eight sheep was inoculated with saline solution and used as mock-vaccinated control animals. Seventy-eight days after the first vaccination, all sheep were inoculated subcutaneously with a suspension containing 10(6.3) TCID(50) of a virulent reference BTV-16 isolate. Apart from a transient inflammatory reaction at the injection site, no adverse effects were reported following vaccination. All vaccinated animals developed high titres (7.3-9.3log(2)(ED50%/50 microl)) of virus-specific neutralising antibodies and were resistant to challenge with BTV-16. Conversely, following challenge, control animals developed hyperthermia and long lasting high-titre viraemia. 相似文献
10.
Long MT Gibbs EP Mellencamp MW Zhang S Barnett DC Seino KK Beachboard SE Humphrey PP 《Equine veterinary journal》2007,39(6):486-490
REASON FOR PERFORMING STUDY: West Nile virus (WNV) infection is endemic and able to cause disease in naive hosts. It is necessary therefore to evaluate the safety of new vaccines. OBJECTIVES: To establish: 1) the safety of a modified live Flavivirus/West Nile virus (WN-FV) chimera by administration of an overdose and testing for shed of vaccine virus and spread to uninoculated sentinel horses; 2) that this vaccine did not become pathogenic once passaged in horses; and 3) vaccine safety under field conditions. METHODS: There were 3 protocols: 1) In the overdose/shed and spread study, horses were vaccinated with a 100x immunogenicity overdose of WN-FV chimera vaccine and housed with sentinel horses. 2) A reversion to virulence study, where horses were vaccinated with a 20x immunogenicity overdose of WN-FV chimera vaccine. Horses in both studies were evaluated for abnormal health conditions and samples obtained to detect virus, seroconversion and dissemination into tissues. 3) In a field safety test 919 healthy horses of various ages, breeds and sex were used. RESULTS: Vaccination did not result in site or systemic reactions in either experimental or field-injected horses. There was no shed of vaccine virus, no detection of vaccine virus into tissue and no reversion to virulence with passage. CONCLUSIONS: WN-FV chimera vaccine is safe to use in horses with no evidence of ill effects from very high doses of vaccine. There was no evidence of reversion to virulence. In addition, administration of this vaccine to several hundred horses that may have been previously exposed to WNV or WNV vaccine resulted in no untoward reactions. POTENTIAL RELEVANCE: These studies establish that this live attenuated Flavivirus chimera is safe to use for immunoprophylaxis against WNV disease in horses. 相似文献