全文获取类型
收费全文 | 335篇 |
免费 | 5篇 |
专业分类
林业 | 15篇 |
农学 | 13篇 |
基础科学 | 3篇 |
90篇 | |
综合类 | 36篇 |
农作物 | 21篇 |
水产渔业 | 21篇 |
畜牧兽医 | 107篇 |
园艺 | 16篇 |
植物保护 | 18篇 |
出版年
2023年 | 3篇 |
2022年 | 5篇 |
2021年 | 5篇 |
2020年 | 10篇 |
2019年 | 12篇 |
2018年 | 7篇 |
2017年 | 9篇 |
2016年 | 8篇 |
2015年 | 9篇 |
2014年 | 11篇 |
2013年 | 30篇 |
2012年 | 14篇 |
2011年 | 19篇 |
2010年 | 22篇 |
2009年 | 10篇 |
2008年 | 16篇 |
2007年 | 20篇 |
2006年 | 24篇 |
2005年 | 18篇 |
2004年 | 10篇 |
2003年 | 14篇 |
2002年 | 10篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1998年 | 3篇 |
1996年 | 2篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 4篇 |
1991年 | 1篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1981年 | 6篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1974年 | 1篇 |
1973年 | 3篇 |
1972年 | 2篇 |
1971年 | 2篇 |
1966年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有340条查询结果,搜索用时 15 毫秒
331.
332.
C A Pinkert J Manz P J Linton N R Klinman U Storb 《Veterinary immunology and immunopathology》1989,23(3-4):321-332
The rearrangement of heavy and light chain immunoglobulin genes is necessary for the production of functional antibody molecules. The myeloma MOPC 167 produces specific antibodies to the antigen phosphorylcholine (PC), which is present on bacterial surfaces, fungi and other environmental contaminants. Rearranged heavy and light chain immunoglobulin genes cloned from MOPC 167 were microinjected into mouse eggs. Within the resulting transgenic mice, expression of the transgenes were limited to lymphoid tissues. Transgenic mice produced elevated levels of anti-PC antibodies constitutively, at 16 days of age, when normal non-transgenic mice were not fully immunocompetent. A triggering antigenic stimulus was not necessary to evoke anti-PC immunoglobulin production. Additionally, the frequency of PC-responsive B cells in these transgenic mice was further increased upon specific immunization. 相似文献
333.
334.
335.
336.
Dietrich FS Voegeli S Brachat S Lerch A Gates K Steiner S Mohr C Pöhlmann R Luedi P Choi S Wing RA Flavier A Gaffney TD Philippsen P 《Science (New York, N.Y.)》2004,304(5668):304-307
We have sequenced and annotated the genome of the filamentous ascomycete Ashbya gossypii. With a size of only 9.2 megabases, encoding 4718 protein-coding genes, it is the smallest genome of a free-living eukaryote yet characterized. More than 90% of A. gossypii genes show both homology and a particular pattern of synteny with Saccharomyces cerevisiae. Analysis of this pattern revealed 300 inversions and translocations that have occurred since divergence of these two species. It also provided compelling evidence that the evolution of S. cerevisiae included a whole genome duplication or fusion of two related species and showed, through inferred ancient gene orders, which of the duplicated genes lost one copy and which retained both copies. 相似文献
337.
Anita M. Ezzo 《Journal Of Agricultural & Food Information》2013,14(3):171-172
No abstract available for this article. 相似文献
338.
Population recovery is difficult for species that require large contiguous areas of habitat, particularly within areas of
heterogeneous land ownerships. Ecologically, potential for recovery success requires assessment of quantity, quality, and
distribution of available habitat. Our objective was to evaluate habitat for a possible Louisiana black bear recovery in southeastern
Texas. First, we categorized land cover and identified remote areas of highly suitable habitat. Next, we used the individual
based simulation model J-walk to estimate ability of female black bears to move among remote habitat patches. Then, we applied
graph theory to J-walk output to evaluate overall connectivity of remote habitat. An estimated 225,626 ha of remote habitat
were identified in 901 patches, most of which was located within the eastern half of the study area. Network analysis showed
specific areas where targeted conservation efforts may help black bear population expansion throughout the study region. Ultimately,
enough habitat area exists to sustain a black bear population and it is best connected among public and private lands largely
within the eastern half of the study area. Habitat evaluation will need to be revisited if black bears establish themselves
locally and actual habitat use data become available. Regardless, our analysis demonstrates an important first step that may
be incorporated into a larger adaptive management framework, updated, and replicated as more-detailed habitat suitability
and land use data are available. 相似文献
339.
Hanna Ungar-Waron Anita Gluckman Ze'ev Trainin 《Tropical animal health and production》1989,21(3):205-210
Summary A simple ELISA test has been developed for the detection of IgG and IgM antibodies to Akabane virus in bovine serum. The test is specific and its sensitivity higher than the serum neutralisation assay. Detection of IgM antibodies can serve as a rapid method of diagnosing primary infection with Akabane virus. The superiority of ELISA resides mainly in the rapidity of performance and that it can be performed with inactivated reagents at high dilutions of serum samples. Thus it might enable the surveillance of spread of infection in zones prone to be affected by insect-borne viral diseases.
La Prueba Elisa Para El Serodiagnostico De La Infeccion En Bovinos Con El Virus De Akabane
Resumen Se desarrolló una prueba ELISA simple, para la detección en sueor bovino de anticuerpos IgG e IgM del virus de Okabane. La prueba es específica y la sensibilidad superior a aquella de la seroneutralización. La detección de anticuerpos IgM puede servir como un método diagnóstico rápido para detectar infecciones primarias causadas por el virus. La superioridad de la prueba ELISA reside principalmente, en la rapidez de ejecución de la misma y que ésta puede realizarse con reactivos inactivados, a altas diluciones de la muestra de suero. Esta prueba ELISA podría facilitar la vigilancia epidemioloógica de la extensión de la enfermedad, en zonas en donde las condiciones ecológicas facilitarían el establecimiento de infecciones transmitidas por insectos.
Un Test Elisa Pour Le Serodiagnostic De L'Infection A Virus Akabane Chez Le Betail
Résumé Un test ELISA simple a été développé pour la détection dans le sérum bovin des anticorps IgG et IgM dirigés contre le virus Akabane. Le test est spécifique et sa sensibilité est supérieure à celle du test de séro-neutralisation. La détection des anticorps IgM peut servir de méthode rapide pour diagnostiquer une infection primaire par le virus Akabane. La supériorité de l'ELISA réside essentiellement dans la rapidité de son exécution et en ce qu'il peut être réalisé avec des réactifs inactivés, et a de hautes dilutions des échantillons de sérums. De la sorte, il permet la surveillance de la propagation de l'infection dans les zones aptes à être affectées par les maladies transmises par arthropodes.相似文献
340.
Shipra Singh Anita Pandey Bhavesh Kumar Lok Man S. Palni 《Biology and Fertility of Soils》2010,46(5):427-433
The present study was undertaken to determine the effect of inoculation with arbuscular mycorrhizal fungi (AMF) from natural
and cultivated tea rhizospheres (NTR and CTR, respectively) on growth as well as on quality parameters of tea [Camellia sinensis (L.) O. Kuntze]. Seeds (after germination) and cuttings were inoculated with AMF consortia from NTR and CTR in non-sterilized
acid soil (pH 5.0). Seedlings and cuttings were grown under net-house conditions and the data on growth and quality parameters
were recorded up to 2 years. Tea plants were found to be highly colonized by AMF (74–83%) after 1 year. The significant increase
in most of the growth parameters (root/shoot length, dry weight; r/s ratio) was recorded in AMF-treated plants, which also
showed better tea quality parameters than noninoculated plants. Maximum significant increases up to 31% and 100%, over control,
were recorded in amino acids and total protein content, respectively. Similarly, maximum increase in total polyphenols (15%)
and caffeine content (34%) over control was also significant. Enhanced sugar content (maximum 16% in total soluble sugars,
maximum 45% in reducing sugars, and maximum 69% in non-reducing sugars) was recorded in AMF-inoculated plants. In most cases,
better response was observed in tea plants inoculated with AMF consortia from NTR. These results indicate that growth and
quality of tea can be improved by AMF inoculations in acid soils. 相似文献