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41.
Diego Valderrama Junning Cai Nathanael Hishamunda Neil Ridler Iain C. Neish Anicia Q. Hurtado 《Aquaculture Economics & Management (Blackwell Science)》2013,17(2):251-277
The farming of the red seaweed Kappaphycus alvarezii and related species as raw material for the hydrocolloid carrageenan rapidly spread from the Philippines in the late 1960s to Indonesia, Tanzania, and other tropical countries around the world. Although numerous studies have documented positive socioeconomic impacts for seaweed farming, factors such as diseases and distance to export markets have led to an uneven development of the industry. Using standard budgeting techniques, this study adapted production and market data from a FAO-led global review of seaweed farming to develop comparative enterprise budgets for eight farming systems in six countries (Indonesia, the Philippines, Tanzania, India, Solomon Islands, and Mexico). Although the basic technology package is the same across countries, the study revealed large differences in the economic performance of systems due to wide variations in farm prices and the scale of operations. Although seaweed farming is a suitable activity for small-scale producers, a minimum of 2,000 m of cultures lines are still necessary to ensure adequate economic returns. Greater farming plots may be needed if farm prices are well below the average farm prices paid in Indonesia and the Philippines. Policy recommendations are made to improve the economic potential of underperforming systems. 相似文献
42.
Carly J. Stevens Iain Fraser Jonathan Mitchley Matthew B. Thomas 《Landscape Ecology》2007,22(6):799-809
In this paper, we ask why so much ecological scientific research does not have a greater policy impact in the UK. We argue
that there are two potentially important and related reasons for this failing. First, much current ecological science is not
being conducted at a scale that is readily meaningful to policy-makers. Second, to make much of this research policy-relevant
requires collaborative interdisciplinary research between ecologists and social scientists. However, the challenge of undertaking
useful interdisciplinary research only re-emphasises the problems of scale: ecologists and social scientists traditionally
frame their research questions at different scales and consider different facets of natural resource management, setting different
objectives and using different language. We argue that if applied ecological research is to have greater impact in informing
environmental policy, much greater attention needs to be given to the scale of the research efforts as well as to the interaction
with social scientists. Such an approach requires an adjustment in existing research and funding infrastructures. 相似文献
43.
Berendzen K Searle I Ravenscroft D Koncz C Batschauer A Coupland G Somssich IE Ulker B 《Plant methods》2005,1(1):4
Background
Many established PCR-based approaches in plant molecular biology rely on lengthy and expensive methods for isolation of nucleic acids. Although several rapid DNA isolation protocols are available, they have not been tested for simultaneous RNA isolation for RT-PCR applications. In addition, traditional map-based cloning technologies often use ill-proportioned marker regions even when working with the model plant Arabidopsis thaliana, where the availability of the full genome sequence can now be exploited for the creation of a high-density marker systems. 相似文献44.
45.
Transmission of equine influenza virus to dogs 总被引:1,自引:0,他引:1
Crawford PC Dubovi EJ Castleman WL Stephenson I Gibbs EP Chen L Smith C Hill RC Ferro P Pompey J Bright RA Medina MJ Johnson CM Olsen CW Cox NJ Klimov AI Katz JM Donis RO 《Science (New York, N.Y.)》2005,310(5747):482-485
Molecular and antigenic analyses of three influenza viruses isolated from outbreaks of severe respiratory disease in racing greyhounds revealed that they are closely related to H3N8 equine influenza virus. Phylogenetic analysis indicated that the canine influenza virus genomes form a monophyletic group, consistent with a single interspecies virus transfer. Molecular changes in the hemagglutinin suggested adaptive evolution in the new host. The etiologic role of this virus in respiratory disease was supported by the temporal association of rising antibody titers with disease and by experimental inoculation studies. The geographic expansion of the infection and its persistence for several years indicate efficient transmission of canine influenza virus among greyhounds. Evidence of infection in pet dogs suggests that this infection may also become enzootic in this population. 相似文献
46.
Loftus BJ Fung E Roncaglia P Rowley D Amedeo P Bruno D Vamathevan J Miranda M Anderson IJ Fraser JA Allen JE Bosdet IE Brent MR Chiu R Doering TL Donlin MJ D'Souza CA Fox DS Grinberg V Fu J Fukushima M Haas BJ Huang JC Janbon G Jones SJ Koo HL Krzywinski MI Kwon-Chung JK Lengeler KB Maiti R Marra MA Marra RE Mathewson CA Mitchell TG Pertea M Riggs FR Salzberg SL Schein JE Shvartsbeyn A Shin H Shumway M Specht CA Suh BB Tenney A Utterback TR Wickes BL Wortman JR Wye NH Kronstad JW Lodge JK 《Science (New York, N.Y.)》2005,307(5713):1321-1324
47.
Geochemical studies in a remote scottish upland catchment II. Streamwater chemistry during snow-melt
Peter W. Abrahams Martyn Tranter Trevor D. Davies Iain L. Blackwood 《Water, air, and soil pollution》1989,43(3-4):231-248
‘Acid-flush’ events, monitored in an upland catchment in the Cairngorm Mountains (Scotland) at the time of the spring-thaw, are associated with an increase in stream discharge and raised concentrations of both major ions (Ca, Mg, Na, Cl, N03, and SO,) and trace-elements (Al, Cd, Cu, Fe, Mn, and Pb), in addition to H+. The streamwater chemistry is determined by the hydrological pathways which are operative in the catchment during these periods of snowmelt, and reflects both the meltwater composition and the influence of the soils within the catchment. Aluminium, in particular, is leached from the soils and high concentrations (up to 330 μg L?1) occur in the streamwaters. The presence of frozen soils, which result largely due to the influence of meteorological conditions prior to the accumulation of the snowpack, is likely to have a large impact on the Al concentrations in the streamwaters. The low concentrations of Ca monitored in the stream during the periods of snow-melt (<0.2 mg L?1) may promote subsequent toxic effects of the Al to aquatic life forms.[/p] 相似文献
48.
Melissa de Oliveira Santos-Garcia Rosângela Maria Simeão Resende Lucimara Chiari Maria Imaculada Zucchi Anete Pereira de Souza 《Euphytica》2011,178(2):185-193
Stylosanthes capitata and S. guianensis are important forage legumes for tropical areas. The only available estimates of S. capitata and S. guianensis outcrossing rates were based on morphological markers, and the genus is considered as being mainly self-pollinated. Here
we describe an estimation of the outcrossing rate in S. capitata and S. guianensis using microsatellite markers. The outcrossing rates were estimated in S. capitata and S. guianensis open-pollinated populations of 20 progenies consisting of ten individuals each. The multi locus outcrossing rate for S. capitata was estimated using 10 polymorphic loci, whereas five microsatellites were used for S. guianensis. The multi locus outcrossing rates for S. capitata and S. guianensis were 31 and 26%, respectively, suggesting a mixed mating system with predominance of autogamy. Comparison of single locus
and multi locus estimates of outcrossing rates indicated that little inbreeding other than selfing occurred. The estimated
Wright’s fixation index of the parental generation was lower than expected based on the multi locus outcrossing rate, possibly
resulting from the use of some heterozygous breeding genotypes for the study. The data on the outcrossing rate described here
are potentially useful for breeding programs and for maintenance of germplasm collections of these Stylosanthes species. 相似文献
49.
Empirical models for estimating the concentrations and exports of metals in rural rivers and streams
Concentrations of Al, Fe, Mn, Zn and Cu were measured monthly at 24 sites in 21 rivers in Ontario and Quebec. Relationships between metal and suspended particulate matter (SPM), turbidity, colour (g440), temperature and system hydrology were quantified, and used to derive empirical models for predicting metal concentrations. In a test of the models using an independent data set, they explained a significant proportion of the variation in Al (90%), Fe (85%), and Mn (57%), but only 37% of the variation in riverine Zn concentrations. Metals concentrations are most strongly associated with SPM concentrations. The proportion of the total metal load associated with particulates (>0.45 μm) is highly variable below 10 ppm SPM, indicating that this concentration approximates the division between systems dominated by weathered (solution) versus eroded (particulate) inputs. Annual metal exports were calculated, and empirical models for predicting catchment exports were developed using system hydrology and average SPM concentrations. These simple models can be used to estimate metals concentrations and exports from routine water quality monitoring data, without requiring chemical analyses. They also serve to distinguish background levels from those indicating metal contamination, and will, therefore, be useful for water quality evaluation. 相似文献
50.