全文获取类型
收费全文 | 118篇 |
免费 | 14篇 |
专业分类
林业 | 4篇 |
农学 | 12篇 |
基础科学 | 1篇 |
16篇 | |
综合类 | 26篇 |
农作物 | 2篇 |
水产渔业 | 15篇 |
畜牧兽医 | 47篇 |
园艺 | 1篇 |
植物保护 | 8篇 |
出版年
2023年 | 1篇 |
2019年 | 2篇 |
2018年 | 2篇 |
2017年 | 3篇 |
2016年 | 4篇 |
2015年 | 5篇 |
2014年 | 7篇 |
2013年 | 9篇 |
2012年 | 4篇 |
2011年 | 7篇 |
2010年 | 6篇 |
2009年 | 3篇 |
2008年 | 8篇 |
2007年 | 2篇 |
2006年 | 5篇 |
2004年 | 4篇 |
2003年 | 3篇 |
2002年 | 2篇 |
2000年 | 6篇 |
1999年 | 5篇 |
1998年 | 3篇 |
1997年 | 3篇 |
1996年 | 4篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 3篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1966年 | 2篇 |
1963年 | 1篇 |
1953年 | 1篇 |
1948年 | 2篇 |
1946年 | 1篇 |
1944年 | 1篇 |
1941年 | 1篇 |
1940年 | 1篇 |
1938年 | 2篇 |
1928年 | 1篇 |
排序方式: 共有132条查询结果,搜索用时 15 毫秒
1.
2.
3.
Towards sustainable exhibits – application of an inorganic fertilization method in coral reef fish larviculture in an aquarium 下载免费PDF全文
Kwee Siong Tew Yun‐Chen Chang Pei‐Jie Meng Ming‐Yih Leu David C Glover 《Aquaculture Research》2016,47(9):2748-2756
Coral reef fish are collected from the wild and exhibited in aquaria worldwide. Some of the fish spawn in captivity; however, the eggs are usually neglected. In this study, we collected the eggs spawned naturally in the exhibit tanks, hatched and cultured them indoor in 2000‐L fibreglass tanks (initial density = 18 000 egg tank?1). We applied an inorganic fertilization method commonly used in freshwater fish culture in raising these coral reef fish larvae. We maintained inorganic phosphorus concentration at 100 μg P L?1 and inorganic nitrogen at 700 μg N L?1 daily in the fertilized group (n = 4), while the control tanks (n = 4) were fed with rotifers (10 ind mL?1). Chlorophyll a at particle sizes of both 0.45–20 μm and >20 μm, as well as NH3‐N, NO3‐N, and PO4‐P concentrations were significantly higher in the fertilized group than the control. Zooplankton in the size groups of 10–50 μm (mainly flagellates) and 50–100 μm (mainly ciliates) were abundant (about 10~60 ind mL?1) during 3–7 days in fertilized tanks. The average larval fish survival rate at 21 day after hatch in fertilized group was consistently higher than the control in two trials. The experiments demonstrated that the inorganic fertilization approach can be successfully adapted for coral reef fish culture in an aquarium to achieve sustainable exhibits. 相似文献
4.
Although rainfall in the United States Mid-South is sufficient to produce corn (Zea mays L.) without irrigation in most years, timely irrigation has been shown to increase yields. The recent interest in ethanol fuels is expected to lead to increases in US corn production, and subsurface drip irrigation (SDI) is one possible way to increase application efficiency and thereby reduce water use. The objective of this study was to determine the response of SDI-irrigated corn produced in the US Mid-South. Field studies were conducted at the University of Arkansas Northeast Research and Extension Center at Keiser during the 2002-2004 growing seasons. The soil was mixed, with areas of fine sandy loam, loamy sand, and silty clay. SDI tubing was placed under every row at a depth of approximately 30 cm. Three irrigation levels were compared, with irrigation replacing 100% and 60% of estimated daily water use and no irrigations. The split plot treatment was hybrid, with three hybrids of different relative maturities. Although the 3-year means indicated significantly lower yields for a nonirrigated treatment, no significant differences were observed among the treatments in 2003 or 2004. A large difference was observed in 2002, the year with the least rainfall during the study period, but no difference was detected between the two irrigated treatments in any year. The treatment with the lower water application had the higher irrigation water use efficiency. Although the results of this study suggested that replacing 60% of the estimated daily evapotranspiration with SDI is sufficient for maximum corn yields, additional observations will be needed to determine whether corn production with SDI is feasible in the region and to develop recommendations for farmers choosing to adopt the method. Improved weather forecasting and crop coefficient functions developed specifically for the region should also contribute to more efficient irrigation management. 相似文献
5.
6.
7.
Holbrook TC Munday JS Brown CA Glover B Schlievert PM Sanchez S 《Journal of the American Veterinary Medical Association》2003,222(5):620-3, 601-2
A 3-year-old Thoroughbred gelding was examined because of clinical signs of pneumonia and shock. Mucous membrane petechiation and ventral edema were observed and considered to be a result of vasculitis. Epidermal necrosis developed on the distal portions of the limbs. The horse had a persistent high fever that was unresponsive to nonsteroidal anti-inflammatory treatment, and Staphylococcus aureus was isolated from a nasal swab specimen and 2 transtracheal wash fluid samples. Antimicrobial, anti-inflammatory, and supportive treatment resulted in clinical improvement. However, resolution of the pulmonary infection required long-term (42 days) antimicrobial administration. Staphylococcus aureus strains isolated from this horse were positive for the toxic shock syndrome toxin-1 gene and were shown to produce toxic shock syndrome toxin-1, the causative factor in toxic shock syndrome in humans. The horse's clinical signs were attributed to toxic shock syndrome secondary to pulmonary S. aureus infection. 相似文献
8.
Brian J McCluskey Brandy Burgess James Glover Hailu Kinde Sharon Hietala 《Journal of veterinary diagnostic investigation》2006,18(3):296-299
The use of sentinel chickens in establishing the negative status of commercial poultry flocks depopulated due to exotic Newcastle disease (END) is considered to be an economically beneficial process. However, the costs and benefits of using sentinel chickens in noncommercial operations are in question. The objective of this study was to use sentinel chickens to evaluate whether adequate cleaning and disinfection coupled with an appropriate time period without susceptible poultry species on the premises would eliminate END virus from a noncommercial poultry operation and preclude the need for placement of sentinels in previously infected operations before declaring them free of virus. Noncommercial poultry operations were selected from the 2002 to 2003 END outbreak database. Operations included in the study had one or more isolations of END virus (ENDV) from cloacal or oropharyngeal swabs of birds on the premises. A total of 546 birds were placed on 53 premises. All sentinel birds sampled after placements were negative by virus detection methods and serologic tests. Results of this study indicate that time and the application of appropriate cleaning and disinfection procedures will adequately mitigate the risk of viable virus persisting in noncommercial poultry operations. In the future, this information may eliminate the need for sentinel bird placement to ensure virus free status of premises before repopulation, thereby decreasing the costs of END eradication. 相似文献
9.
Objective To evaluate standing, percutaneous, ultrasound-guided, transthoracic liver biopsy in mares, and transabdominal, laparoscopically-guided, liver biopsy under general anaesthesia in foals, as techniques for obtaining tissue for assessment of copper status. The techniques were evaluated with respect to ease of use and effect on the animal.
Procedure Twenty of 24 Thoroughbred mares and 21 of their foals were biopsied. The animals were part of a larger study of the effect of copper supplementation on copper status and the prevalence of developmental orthopaedic disease. Livers were also collected from unrelated horses and sampled to investigate the variability in the distribution of copper in liver tissue.
Result The biopsy technique caused no lasting effect on the mares, but there was an increased risk of viscus penetration associated with taking multiple biopsy cores. The use of ultrasonography to scan the target area for the liver identified four cases that were not appropriate candidates for liver biopsy, because of large intestine being located in the biopsy area. In the foals there were no serious postoperative adverse effects, nor was there any evidence of problems caused by the procedure when the abdomen was examined post-mortem at 5 months of age. In livers collected to investigate the variability of copper concentration, copper appeared to be relatively evenly distributed through the liver.
Conclusion Standing, percutaneous, ultrasound-guided, transthoracic liver biopsy in mares, and transabdominal, laparoscopically-guided, liver biopsy under general anaesthesia in foals are convenient procedures for obtaining liver tissue for assessing copper status in horses. The use of ultrasound to identify liver tissue is recommended, especially in older mares. 相似文献
Procedure Twenty of 24 Thoroughbred mares and 21 of their foals were biopsied. The animals were part of a larger study of the effect of copper supplementation on copper status and the prevalence of developmental orthopaedic disease. Livers were also collected from unrelated horses and sampled to investigate the variability in the distribution of copper in liver tissue.
Result The biopsy technique caused no lasting effect on the mares, but there was an increased risk of viscus penetration associated with taking multiple biopsy cores. The use of ultrasonography to scan the target area for the liver identified four cases that were not appropriate candidates for liver biopsy, because of large intestine being located in the biopsy area. In the foals there were no serious postoperative adverse effects, nor was there any evidence of problems caused by the procedure when the abdomen was examined post-mortem at 5 months of age. In livers collected to investigate the variability of copper concentration, copper appeared to be relatively evenly distributed through the liver.
Conclusion Standing, percutaneous, ultrasound-guided, transthoracic liver biopsy in mares, and transabdominal, laparoscopically-guided, liver biopsy under general anaesthesia in foals are convenient procedures for obtaining liver tissue for assessing copper status in horses. The use of ultrasound to identify liver tissue is recommended, especially in older mares. 相似文献
10.
An anonymous, self-administered questionnaire has been used in two independent surveys to try to determine the prevalence of scrapie in the national sheep flock. The disease was recorded in 35 counties in England and Wales. About a third (26.5 and 37.3 percent) of respondents owning 100 or more sheep indicated that they had seen sheep with scrapie in their flocks. The incidences of clinical cases recorded in affected flocks in the two surveys were 0.5 and 1.1 cases/100 ewes/year. At present there is no control over the disposal of these animals. If as has been suggested, an increase in the prevalence of scrapie was a contributory factor in the emergence of bovine spongiform encephalopathy, it would seem logical that measures should be introduced to monitor the prevalence and incidence of scrapie and to control the disposal of clinical cases. 相似文献