全文获取类型
收费全文 | 479篇 |
免费 | 43篇 |
专业分类
林业 | 29篇 |
农学 | 18篇 |
83篇 | |
综合类 | 14篇 |
农作物 | 29篇 |
水产渔业 | 69篇 |
畜牧兽医 | 224篇 |
园艺 | 9篇 |
植物保护 | 47篇 |
出版年
2024年 | 1篇 |
2023年 | 4篇 |
2022年 | 19篇 |
2021年 | 25篇 |
2020年 | 37篇 |
2019年 | 33篇 |
2018年 | 30篇 |
2017年 | 28篇 |
2016年 | 27篇 |
2015年 | 21篇 |
2014年 | 24篇 |
2013年 | 28篇 |
2012年 | 34篇 |
2011年 | 37篇 |
2010年 | 16篇 |
2009年 | 17篇 |
2008年 | 23篇 |
2007年 | 18篇 |
2006年 | 12篇 |
2005年 | 14篇 |
2004年 | 9篇 |
2003年 | 14篇 |
2002年 | 6篇 |
2001年 | 2篇 |
2000年 | 8篇 |
1999年 | 6篇 |
1998年 | 5篇 |
1997年 | 1篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1992年 | 1篇 |
1991年 | 3篇 |
1989年 | 2篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1975年 | 1篇 |
1974年 | 3篇 |
1971年 | 3篇 |
1969年 | 1篇 |
1966年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有522条查询结果,搜索用时 16 毫秒
51.
52.
53.
Alessio Dileta Regina Moro Velho João Pedro Tambara Antônio Augusto Cortiana de Oliveira Gomes Ivan Pedro Knob Deise Aline Haygert-Velho Ione Maria Pereira Busanello Marcos Thaler Neto André 《Tropical animal health and production》2020,52(1):185-193
Tropical Animal Health and Production - To reduce costs, lactating cows are often fed a higher proportion of roughage and alternative feeds; however, such protocols may not lead to optimal milk... 相似文献
54.
Carolina M. Muniz Natália C. L. dos Santos Matheus T. Baumgartner Angelo A. Agostinho Luiz C. Gomes 《Ecology of Freshwater Fish》2020,29(2):241-251
One of the main impacts on aquatic environments is the alteration of flow regime, usually caused by dam construction. This impact changes the dynamics and functioning of the environment. We aimed to evaluate changes in the composition of functional traits of fish assemblages from 29 reservoirs of different chronological ages. We assessed if there were any alterations in trophic state of these reservoirs according to their ages (chronological variable). Then, we evaluated the relationship between functional traits and environmental/chronological variables. Results showed that reservoir age is a predictor of fish assemblage functional traits composition. In older reservoirs, there was a predominance of omnivorous species, with multiple spawning and parental care. However, herbivorous species, with total spawning and medium size, had their abundance reduced. Also, it was possible to identify the influence of depth and water retention time on the composition of functional traits. By showing that although age has an influence on composition, the intrinsic characteristics of each reservoir are very important in evaluating the impacts of these projects. Therefore, the findings presented provide insights into what may happen to functional traits of fish assemblages with ageing of reservoirs. 相似文献
55.
Neto JO Azevedo SS Gennari SM Funada MR Pena HF Araújo AR Batista CS Silva ML Gomes AA Piatti RM Alves CJ 《Veterinary parasitology》2008,156(3-4):329-332
The prevalence and risk factors for anti-Toxoplasma gondii antibodies were investigated in goats of the Seridó Oriental microregion, Rio Grande do Norte state, Northeast region of Brazil. Three hundred and sixty-six blood samples from goats collected by jugular venopuncture were used. For the serologic diagnosis of Toxoplasma gondii infection, the indirect fluorescent-antibody test (IFAT) with cut-off value 1:64 was carried out. The prevalence of anti-T. gondii antibodies was 30.6% [95% CI=25.9-35.6%] with titers ranging from 1:64 to 1:16,384. The multivariate logistic regression analysis showed that the risk factors associated to anti-T. gondii antibodies were presence of cats in the herd, extensive/semi-intensive management systems and lack of mineral supplementation. 相似文献
56.
Gomes YM Paiva Cavalcanti M Lira RA Abath FG Alves LC 《Veterinary journal (London, England : 1997)》2008,175(1):45-52
Human visceral leishmaniasis (HVL) is endemic in the tropical and sub-tropical regions of Africa, Asia, the Mediterranean, Southern Europe and South and Central America, with approximately 500,000 new cases reported annually. As dogs are considered to be the major reservoirs for HVL, the accurate diagnosis of disease in these animals is important. Diagnosis of canine visceral leishmaniasis (CVL) is performed mainly by direct parasitological methods that can yield false-negative results, either because of the very low number of Leishmania spp. organisms in clinical samples (bone marrow and lymph nodes) or because morphological identification is difficult. In addition, these methods are invasive. Conventional serological techniques are limited by cross-reactivity with other parasitic diseases and because several technical procedures have not been standardised. The development of polymerase chain reaction based approaches and immunoassays based on the use of recombinant antigens aimed at improving the sensitivity and specificity of CVL diagnosis is discussed. 相似文献
57.
Tcia Gomes Bergstein‐Galan Romildo Romualdo Weiss Luiz Ernandes Kozicki 《Reproduction in domestic animals》2019,54(2):401-407
Multiple ovulation and embryo transfer (MOET) is an important tool in the sheep industry for increasing numbers of genetically superior individuals. The objective of this study was to evaluate the effect of semen source (frozen or fresh), the number of embryo collection procedures for each donor (NECP), the season in which embryo transfer and collection was performed, and the age and breed of the donor, on the number of recovered embryos and pregnancy rates after embryo transfer. The Alamos Genetics’ flushing station database was used. This consisted of 140 embryo collection procedures, from 53 Dorper and White Dorper sheep donors, aged between one and eight years, totalling 1,200 collected embryos. Neither the number of retrieved embryos nor the pregnancy rate was affected by the semen preservation method (fresh or frozen), NECP or the age and breed of donor. The season did not affect the number of collected embryos but had a significant effect (p < 0.05) on the recipient pregnancy rate, with higher pregnancy rates reported in the winter (65.57% ± 25.33%) compared with spring (37.11% ± 33.27%), summer (29.95% ± 28.33%) or autumn (35.03% ± 31.66%). There is an estimated increase of 98.4% and 71.5% of embryos recovered in the spring and summer seasons, respectively, when winter is used as reference. The survival of embryos is significantly higher when implanted during the breeding season, more specifically in winter. Embryo collection can be carried out throughout the year in sheep, but there may be a marginal advantage in the use of superovulation and fresh embryo transfer programmes in the autumn and winter. 相似文献
58.
da Silva José Ricardo Coelho de Carvalho Francisco Fernando Ramos de Andrade Fereira Marcelo de Souza Evaristo Jorge Oliveira Maciel Maria Inês Sucupira Barreto Lígia Maria Gomes Lopes Levi Auto Cordeiro Eduardo Henrique Araújo Véras Antonia Sherlânea Chaves 《Tropical animal health and production》2019,51(8):2455-2463
Tropical Animal Health and Production - The objective of this study was to evaluate carcass characteristics, meat quality, and organ and viscera weight of forty male sheep, not castrated, initially... 相似文献
59.
60.
Antibody phage display libraries are a useful tool in proteomic analyses. This study evaluated an antibody recombinant library for identification of sex-specific proteins on the sperm cell surface. The Griffin.1 library was used to produce phage antibodies capable of recognizing membrane proteins from Nelore sperm cells. After producing soluble monoclonal scFv, clones were screened on Simental sperm cells by flow cytometry and those that bound to 40–60% of cells were selected. These clones were re-analyzed using Nelore sperm cells and all clones bound to 40–60% of cells. Positive clones were submitted to a binding assay against male and female bovine leukocytes by flow cytometry and one clone preferentially bound to male cells. The results indicate that phage display antibodies are an alternative method for identification of molecules markers on sperm cells. 相似文献