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131.
Landscape Ecology - Biodiversity monitoring programs require fast, reliable and cost-effective methods for biodiversity assessment in landscapes. Sampling pollinators across entire landscapes is... 相似文献
132.
The evolution of multiple‐insecticide resistance in UK populations of tomato leafminer,Tuta absoluta
133.
134.
In this study we provide a protocol for genotyping Clostridium perfringens with a new multiplex PCR. This PCR enables reliable and specific detection of the toxin genes cpa, cpb, etx, iap, cpe and cpb2 from heat lysed bacterial suspensions. The efficiency of the protocol was demonstrated by typing C. perfringens reference strains and isolates from veterinary bacteriological routine diagnostic specimens. 相似文献
135.
The tremendous variability in physical conditions of forest enterprises as well as attitudinal aspects of their managers is
seen as a major impediment to the understanding and optimization of forest management. For this reason, former studies using
several methodological approaches—including meta analysis of econometric studies, binary choice models and stochastic frontier
models—in many cases remained on a qualitative and more holistic level. This paper assesses the applicability of Bayesian
Belief Networks (BBN) for the analysis of net income based on detailed 2006 economic data from the German federal accountancy
network of forest enterprises larger than 200 ha. A network with one dependent (target) and 30 independent (explaining) variables
was designed. The BBN has proven helpful for qualitative and to some extent quantitative analysis of economic data. It has
become obvious that the completeness of populating the BBN model must be seen as a constraint. The speed of the calculations
and the use of dependent probabilities can be seen as benefits of the BBN approach that reduce the risk of misinterpretation
in comparison with traditional analysis methods such as the comparison of different strata. The visibility and presentability
of the BBN approach facilitates its use in controlling and optimizing processes. 相似文献
136.
Inken Krüger Jan Muhr Claudia Hartl-Meier Christoph Schulz Werner Borken 《European Journal of Forest Research》2014,133(5):931-939
To study the decay of coarse woody debris (CWD) in forest ecosystems, it is necessary to determine the time elapsed since tree death, which is difficult at advanced decay stages. Here, we compare two methods for age determination of CWD logs, dendrochronological cross-dating and radiocarbon analysis of the outermost tree ring. The methods were compared using samples from logs of European beech, Norway spruce and Sessile oak decomposing in situ at three different forest sites. For dendrochronological cross-dating, we prepared wood discs with diameters of 10–80 cm. For radiocarbon analysis, cellulose was isolated from shavings of the outermost tree rings. There was an overall good agreement between time of death determined by the two methods with median difference of 1 year. The uncertainty of age determination by the radiocarbon approach did not increase with decreasing carbon density, despite incomplete separation of chitin from the extracted cellulose. Fungal chitin has the potential to alter the radiocarbon signature of tree rings as the carbon for chitin synthesis originates from different sources. Significant correlations between year of tree death and carbon density of wood were found for beech and spruce, but not for oak due to relatively small decreases in carbon density within 50–60 years. Total residence times of CWD were calculated from these correlations and revealed 24 years for beech and 62 years for spruce. The uncertainty of total residence times results mainly from huge natural variability in carbon density of CWD rather than uncertainty in the age determination. The results suggest that both methods are suitable for age determination of CWD. 相似文献
137.
Garance Christen Vinzenz Gerber Gaudenz Dolf Dominique Burger Christoph Koch 《Veterinary journal (London, England : 1997)》2014,199(1):68-71
The mode of inheritance for susceptibility to equine sarcoid disease (ES) remains unknown. The objectives of this study were to analyse a large sample of the Franches-Montagnes (FM) horse population and investigate the heritability and mode of inheritance for susceptibility to ES. Horses were clinically examined for the presence of sarcoid tumours. A standardized examination protocol and client questionnaire were used and a pedigree- and subsequent segregation-analysis for the ES trait performed. To investigate the mode of inheritance, five models were evaluated and compared in a hierarchical way.The analyses reveal that variation in susceptibility to ES is best explained by a model incorporating polygenic variation. The possible effect of a major gene, such as specific equine leukocyte antigen alleles, is unlikely, but cannot be ruled-out entirely. The heritability of the phenotype on the observation scale for the trait ‘affected with ES’ was estimated to be 8%. A corrected value for the heritability on a liability scale was estimated at 21% and it is therefore possible to estimate breeding values for ES. The arguments against the practical implementation of an estimated breeding value in a multifactorial condition like ES are discussed. 相似文献
138.
Roos CF Riebe M Häffner H Hänsel W Benhelm J Lancaster GP Becher C Schmidt-Kaler F Blatt R 《Science (New York, N.Y.)》2004,304(5676):1478-1480
We report the deterministic creation of maximally entangled three-qubit states-specifically the Greenberger-Horne-Zeilinger (GHZ) state and the W state-with a trapped-ion quantum computer. We read out one of the qubits selectively and show how GHZ and W states are affected by this local measurement. Additionally, we demonstrate conditional operations controlled by the results from reading out one qubit. Tripartite entanglement is deterministically transformed into bipartite entanglement by local operations only. These operations are the measurement of one qubit of a GHZ state in a rotated basis and, conditioned on this measurement result, the application of single-qubit rotations. 相似文献
139.
Species richness often peaks at intermediate productivity and decreases as resources become more or less abundant. The mechanisms that produce this pattern are not completely known, but several previous studies have suggested environmental heterogeneity as a cause. In experiments with evolving digital organisms and populations of fixed size, maximum species richness emerges at intermediate productivity, even in a spatially homogeneous environment, owing to frequency-dependent selection to exploit an influx of mixed resources. A diverse pool of limiting resources is sufficient to cause adaptive radiation, which is manifest by the origin and maintenance of phenotypically and phylogenetically distinct groups of organisms. 相似文献
140.
West NP Sansonetti P Mounier J Exley RM Parsot C Guadagnini S Prévost MC Prochnicka-Chalufour A Delepierre M Tanguy M Tang CM 《Science (New York, N.Y.)》2005,307(5713):1313-1317
Shigella, the leading cause of bacillary dysentery, uses a type III secretion system (TTSS) to inject proteins into human cells, leading to bacterial invasion and a vigorous inflammatory response. The bacterium is protected against the response by the O antigen of lipopolysaccharide (LPS) on its surface. We show that bacteriophage-encoded glucosylation of Shigella O antigen, the basis of different serotypes, shortens the LPS molecule by around half. This enhances TTSS function without compromising the protective properties of the LPS. Thus, LPS glucosylation promotes bacterial invasion and evasion of innate immunity, which may have contributed to the emergence of serotype diversity in Shigella. 相似文献