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41.
Pierre Roudier Bruno Tisseyre Hervé Poilvé Jean-Michel Roger 《Precision Agriculture》2011,12(1):130-145
Ten years after the introduction of zone-based management to take into account within-field phenomena in agronomic practices, several methodological developments have progressed to the operational level. However, this raises a new scientific question: how can the relevance of this type of management be evaluated? This paper adapts the concept of a technical opportunity index to zone-specific management. Based on the characteristics of machinery, zoning opportunity is introduced through a new index (ZOI) adapted specifically to zone-based management. This index takes into account the operational conditions in which zoning is applied, together with its associated risks. The results obtained on simulated and real field data highlight the relevance of this index. 相似文献
42.
Jacques Pictet Jean-Michel Giovannoni Lucien Yves Maystre 《Water, air, and soil pollution》1992,63(1-2):155-178
A set of 14 household waste management system scenarios have been ranked according to the environmental impact of their respective refuse outputs. Each system has been characterized by the annual release of 8 chemical elements, namely: S, Cl, Fe, Cu, Zn, Cd, Hg and Pb. The method relies on the determination of a load factor, which is defined as the ratio between the actual pollutant concentration and the accepted norm for this concentration. These figures are calculated via a three box model, where the three boxes are air, water and soil. The model considers the pollutant output from each scenario, the dilution or accumulation in each box as well as dry deposition from air to water and soil. The pollutant load factors are then aggregated in order to obtain a score. These scores allow a final scenario grade to be determined, which can then be used to rank the various scenarios. The final grades are strongly dependant on the presence of deposition terms as well as on the values chosen for the individual pollutant concentration norms, whereas they are reasonably independent of all other parameters. 相似文献
43.
44.
Two new benzylbenzoate glucosides from Curculigo orchioides 总被引:2,自引:0,他引:2
Valls J Richard T Larronde F Leblais V Muller B Delaunay JC Monti JP Ramawat KG Mérillon JM 《Fitoterapia》2006,77(6):416-419
An extract from in vitro cultures of Curculigo orchioides grown as bulbils in shake flasks, afforded two new glucosides of substituted benzylbenzoate - curculigoside C (3) and curculigoside D (4) - together with two known compounds - curculigoside A (1) and curculigoside B (2). Their structures were elucidated on the basis of spectral evidence, in particular by using 2D NMR methods. Their vasoactive properties were assessed in isolated rat aortic rings. 相似文献
45.
Measuring wood density by means of X-ray computer tomography 总被引:1,自引:0,他引:1
Charline Freyburger Fleur Longuetaud Frédéric Mothe Thiéry Constant Jean-Michel Leban 《Annals of Forest Science》2009,66(8):804-804
46.
Guillaume Besnard Virginie Acheré Sylvain Jeandroz Øystein Johnsen Patricia Faivre Rampant Rüdiger Baumann Gerhard Müller-Starck Torre Skrøppa Jean-Michel Favre 《Annals of Forest Science》2008,65(1):109-109
In forest trees, environmental conditions during reproduction can greatly influence progeny performance. This phenomenon probably results from adaptive phenotypic plasticity but also may be associated with genotypic selection. In order to determine whether selective effects during the reproduction are environment specific, single pair-crosses of Norway spruce were studied in two contrasted maternal environments (warm and cold conditions). One family expressed large and the other small phenotypic differences between these crossing environments. The inheritance of genetic polymorphism was analysed at the seed stage. Four parental genetic maps covering 66 to 78% of the genome were constructed using 190 to 200 loci. After correcting for multiple testing, there is no evidence of locus under strong and repeatable selection. The maternal environment could thus only induce limited genotypic-selection effects during reproductive steps, and performance of progenies may be mainly affected by a long-lasting epigenetic memory regulated by temperature and photoperiod prevailing during seed production. 相似文献
47.
Marcel van Oijen Jean Dauzat Jean-Michel Harmand Gerry Lawson Philippe Vaast 《Agroforestry Systems》2010,80(3):341-359
Research on coffee agroforestry systems in Central America has identified various environmental factors, management strategies
and plant characteristics that affect growth, yield and the impact of the systems on the environment. Much of this literature
is not quantitative, and it remains difficult to optimise growing area selection, shade tree use and management. To assist
in this optimisation we developed a simple dynamic model of coffee agroforestry systems. The model includes the physiology
of vegetative and reproductive growth of coffee plants, and its response to different growing conditions. This is integrated
into a plot-scale model of coffee and shade tree growth which includes competition for light, water and nutrients and allows
for management treatments such as spacing, thinning, pruning and fertilising. Because of the limited availability of quantitative
information, model parameterisation remains fraught with uncertainty, but model behaviour seems consistent with observations.
We show examples of how the model can be used to examine trade-offs between increasing coffee and tree productivity, and between
maximising productivity and limiting the impact of the system on the environment. 相似文献
48.
Marcel van Oijen Jean Dauzat Jean-Michel Harmand Gerry Lawson Philippe Vaast 《Agroforestry Systems》2010,80(3):361-378
Research on coffee agroforestry systems in Central America has identified various environmental factors, management strategies and plant characteristics that affect growth, yield and the impact of the systems on the environment. Much of this literature is not quantitative, and it remains difficult to optimise growing area selection, shade tree use and management. To assist in this optimisation we developed a simple dynamic model of coffee agroforestry systems. The model includes the physiology of vegetative and reproductive growth of coffee plants, and its response to different growing conditions. This is integrated into a plot-scale model of coffee and shade tree growth which includes competition for light, water and nutrients and allows for management treatments such as spacing, thinning, pruning and fertilising. Because of the limited availability of quantitative information, model parameterisation remains fraught with uncertainty, but model behaviour seems consistent with observations. We show examples of how the model can be used to examine trade-offs between increasing coffee and tree productivity, and between maximising productivity and limiting the impact of the system on the environment. 相似文献
49.
50.
Jeremy Larroque Sandrine Ruette Jean-Michel Vandel Sébastien Devillard 《Landscape Ecology》2016,31(3):517-531