全文获取类型
收费全文 | 103篇 |
免费 | 9篇 |
专业分类
林业 | 6篇 |
农学 | 1篇 |
28篇 | |
综合类 | 3篇 |
农作物 | 5篇 |
水产渔业 | 10篇 |
畜牧兽医 | 49篇 |
园艺 | 1篇 |
植物保护 | 9篇 |
出版年
2023年 | 2篇 |
2022年 | 2篇 |
2021年 | 5篇 |
2020年 | 3篇 |
2019年 | 3篇 |
2018年 | 1篇 |
2017年 | 3篇 |
2016年 | 4篇 |
2015年 | 4篇 |
2014年 | 7篇 |
2013年 | 8篇 |
2012年 | 7篇 |
2011年 | 8篇 |
2010年 | 3篇 |
2009年 | 3篇 |
2008年 | 4篇 |
2007年 | 6篇 |
2006年 | 7篇 |
2005年 | 5篇 |
2004年 | 2篇 |
2003年 | 4篇 |
2002年 | 2篇 |
2001年 | 3篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1995年 | 1篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1978年 | 1篇 |
1972年 | 2篇 |
1971年 | 1篇 |
1970年 | 2篇 |
1965年 | 1篇 |
排序方式: 共有112条查询结果,搜索用时 234 毫秒
1.
Berit Kvaeven Merete J. Ulstein Brit L. Skjelkvåle Gunnar G. Raddum H. Hovind 《Water, air, and soil pollution》2001,130(1-4):775-780
The International Cooperative Programme on Assessment and Monitoring of Acidification of Rivers and Lakes (ICP Waters) was established in July 1985 under the United Nations Economic Commission for Europe (UN/ECE) Executive Body of the Convention on Long-Range Transboundary Air Pollution (LRTAP). The Programme Centre is at the Norwegian Institute for Water Research, Oslo. The main aim of the Programme is to assess, on a regional basis, the degree and geographical extent of acidification of surface waters. 23 countries in Europe and North America participate on a regular basis. The major findings in the programme cover (1) regional trends in water chemistry related to changes in S- and N-deposition, (2) dose/response relationships particularly between biology (invertebrates) and water chemistry (acidification status), (3) effects of acidification on aquatic fauna, (4) implications for the assessment of critical loads, and (5) nitrogen leaching. Both chemical and biological intercalibrations and intercomparisons are important parts of the programme activities. 相似文献
2.
Effect of hydrogen peroxide as treatment for amoebic gill disease in Atlantic salmon (Salmo salar L.) in different temperatures 下载免费PDF全文
Kristine Hov Martinsen Audur Thorisdottir Marie Lillehammer 《Aquaculture Research》2018,49(5):1733-1739
Amoebic gill disease (AGD) is a pathogenic disease in salmonids caused by Neoparamoeba perurans. Treatment of AGD infection has been through freshwater bathing of the fish. However, as the availability of fresh water is often limited, hydrogen peroxide has been introduced as an alternative treatment. This study investigated the effect of hydrogen peroxide as treatment for AGD‐infected salmon (Salmo salar L.,) at different seawater temperatures and hydrogen peroxide dosages. In total, 600 fish were challenged with N. perurans and the severity of the AGD infection was measured using a gill score scale. After challenge and disease development, the fish were distributed into 12 tanks. The treatment was performed at different seawater temperatures (8°C, 12°C, 17°C) using different hydrogen peroxide doses. Each temperature included an untreated control group. Linear models were used to analyse gill score. A significant effect of treatment was found (?0.68 ± 0.05) regardless of dose and temperature, suggesting that hydrogen peroxide was effective in treating AGD. When the model included dose, a negative linear relationship between dose and gill score was found. The study proved that treatment of AGD with hydrogen peroxide was successful, as gills partially recovered following treatment and further disease development was delayed. 相似文献
3.
4.
5.
Adrian Muwonge Clovice Kankya Jacques Godfroid Berit Djonne John Opuda-Asibo Demelash Biffa Takele Ayanaw Musso Munyeme Eystein Skjerve 《Tropical animal health and production》2010,42(5):905-913
To date, the public health relevance of mycobacterial infections in pigs is not well investigated despite high risk of infection.
Recently, there has been a documented increase in opportunistic infections and risk of acquiring opportunistic mycobacterial
infections in HIV/AIDS patients in Mubende district; unfortunately, there has been no published information on the epidemiology
of mycobacterial infections in this area. This study was carried out between September 2008 and February 2009. Investigations
were done to assess the prevalence and associated risk factors of mycobacterial infections in slaughtered pigs in Mubende
district of Uganda. A total of 997 pigs (53.7% male and 46.3% female) from 31 different slaughterhouses were examined for
the presence of lesions compatible with TB and mycobacterial infections. Pathologic tissue specimens were collected for culturing
and isolation of mycobacteria. A cross-sectional technique was used based on convenient visits to slaughterhouses but random
selection of individual slaughtered pigs for a detailed post-mortem inspection on a daily basis. The results reflected a 9.3%
and 3.1% (95% CI) prevalence of Mycobacterium species based on necropsy examinations and culture isolation, respectively. The highest prevalence of mycobacterial infection
was recorded in Buwekula County (the mixed agro-zone) whilst the lowest was in Kassanda County (pastoral zone). A multivariable
logistical regression analysis identified age (P ≤ 0.001) and sex (P ≤ 0.05) as risk factors for mycobacterial infections in pigs. Post-estimation statistics of the regression model evaluation
and validation fit it well into the data (HL, χ
2 = 5.9; P = 0.69 for necropsy, HL χ
2 = 2.9; P = 0.94 for culturing). This study documented a high prevalence of mycobacterial infections in slaughter pigs in Mubende district.
The fact that pigs and human often share common housing and environment poses a high risk of zoonotic transmission. This then
warrants further molecular investigation to identify the specific Mycobacterium species and their public health importance in this area. 相似文献
6.
Effect of dietary components on the gut microbiota of aquatic animals. A never‐ending story? 下载免费PDF全文
E. Ringø Z. Zhou J.L.G. Vecino S. Wadsworth J. Romero Å. Krogdahl R.E. Olsen A. Dimitroglou A. Foey S. Davies M. Owen H.L. Lauzon L.L. Martinsen P. De Schryver P. Bossier S. Sperstad D.L. Merrifield 《Aquaculture Nutrition》2016,22(2):219-282
It is well known that healthy gut microbiota is essential to promote host health and well‐being. The intestinal microbiota of endothermic animals as well as fish are classified as autochthonous or indigenous, when they are able to colonize the host's epithelial surface or are associated with the microvilli, or as allochthonous or transient (associated with digesta or are present in the lumen). Furthermore, the gut microbiota of aquatic animals is more fluidic than that of terrestrial vertebrates and is highly sensitive to dietary changes. In fish, it is demonstrated that [a] dietary form (live feeds or pelleted diets), [b] dietary lipid (lipid levels, lipid sources and polyunsaturated fatty acids), [c] protein sources (soybean meal, krill meal and other meal products), [d] functional glycomic ingredients (chitin and cellulose), [e] nutraceuticals (probiotics, prebiotics, synbiotics and immunostimulants), [f] antibiotics, [g] dietary iron and [h] chromic oxide affect the gut microbiota. Furthermore, some information is available on bacterial colonization of the gut enterocyte surface as a result of dietary manipulation which indicates that changes in indigenous microbial populations may have repercussion on secondary host–microbe interactions. The effect of dietary components on the gut microbiota is important to investigate, as the gastrointestinal tract has been suggested as one of the major routes of infection in fish. Possible interactions between dietary components and the protective microbiota colonizing the digestive tract are discussed. 相似文献
7.
OBJECTIVE: To examine to what extent the obesity epidemic is a general phenomenon in adults by assessing the secular change, by birth cohort and age, in the prevalence of obesity and median body mass index (BMI) in Danish men and women measured between 1964 and 1994. DESIGN: Multiple cross-sectional population surveys. SETTING: The greater Copenhagen area of Denmark. SUBJECTS: The study included 17,065 men (30 336 observations) and 13,417 women (24,065 observations), aged 20-84 years. MAIN OUTCOME MEASURES: Trends in median BMI and prevalence of obesity estimated from measured height and weight in 10-year age groups. RESULTS: In general the prevalence of obesity was increasing, although in an irregular way: among men in two phases, during the 1970s and 1990s and among women only during the 1990s. Great heterogeneity was observed between birth cohorts and age groups. There was only little indication of an increasing trend in obesity prevalence for women, except for the 55-64-year-olds. In men, the prevalence of obesity was increasing in all age groups except in the youngest ones, and it was statistically significant only for men aged 35-74 years. There was no significant linear change in median BMI in any group, except for an increasing trend among men aged 50 years and above. CONCLUSION: Although the overall Danish trend for obesity prevalence, similar to trends world-wide, showed a marked increase, the trend was very heterogeneous and generally neither uniform nor significantly positive; the changes were irregular, different among men and women, and different in the different age and birth cohorts. The obesity problem in middle-aged and older men of certain birth cohorts poses a specific public health challenge. Future studies of determinants behind the heterogeneity in the development of the obesity epidemic may provide clues to its causes. 相似文献
8.
9.
Cesar Ricardo Arruda Fernanda Ramiro Vanessa Faria Roberto Barcelos Daniel Pontes Fernanda Passos Fabiano Kaiser Karoline dos Santos Teixeira Aline Maria Serrano Aline Abreu Leticia Siqueira Danielle Teixeira Matheus Vezzone Mariana Polivanov Helena Castilhos Zuleica 《Journal of Soils and Sediments》2022,22(2):547-558
Journal of Soils and Sediments - This study consists of the evaluation of metals acute toxicity levels taking into consideration a hypothetic scenario of dam breaking and land deposition of two... 相似文献
10.