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Grabowska Joanna Pietraszewski Dariusz Przybylski Mirosław Tarkan Ali Serhan Marszał Lidia Lampart-Kałużniacka Magdalena 《Hydrobiologia》2011,661(1):197-210
In recent decades, Amur sleeper is one of the most invasive fish species in Eastern and Central Europe. Generally, it is assumed
that success of an invasive species can largely depend on the plasticity of its life-history traits, e.g., indicated by higher
investment in reproduction in the initial stage of its invasion. On the other hand, such energy allocation to production of
gonads should negatively impact somatic growth rate. The aim of this article was to explore this phenomenon in a non-native
population of Amur sleeper inhabiting artificial reservoir on a large lowland river in Central Europe. Through analysis of
the population age structure, sex-dependent growth rate and life-history traits we assessed investment in reproduction and
its possible relationship with growth pattern as well as compared the results with literature data from native and introduced
range. Samples collected monthly from April 2005 to March 2006 were used to estimate sex ratio, GSI, fecundity, eggs diameter
frequency over the year, duration of spawning season, and mode of spawning. Age structure was calculated from scales and the
same data were also used to back-calculate standard length (SL) at age. The population in the Włocławski Reservoir was represented
by eight age groups, and its life span was one of the longest recorded both in its natural range and introduced areas. The
weight–length relationship showed that the Amur sleeper grew isometrically and there was no difference between females and
males. Although the Amur sleeper growth rate was relatively slow in the Włocławski Reservoir, its increment in the first year
of life was comparable to that in other introduced areas and higher than in its natural range. The female age of maturation
(1+) found in the reservoir was earlier than observed in its natural range as well as in most introduced areas (2+, 3+). Female
length at maturation was similar to that reported elsewhere. The back-calculated standard length (SL) of females and males
showed that in the first two age classes (1 and 2) males achieved larger SL than females. Meanwhile, at age 3, 4 and 5, females
were larger than males but these differences were insignificant, except for class 5. For both sexes the average annual increment
of SL decreased with age but in females the increment was always higher than in males (P < 0.05). The growth rate differences between females and males resulted possibly from their unequal investment in reproduction.
Multiple spawning in the Włocławski Reservoir lasted from April to the end of August and was almost 3 months longer than in
other regions. Thus, this higher investment in reproduction displayed by, e.g., earlier maturation of females and longer spawning
season in the Włocławski Reservoir, may contribute to invasive success of Amur sleeper in newly colonized areas; however,
the costs of this strategy result in slower growth in older age classes. 相似文献
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The total concentrations of free phenolic compounds and peroxidase were determined in spikes (collected at the flowering stage)
of some spelt and common wheat cultivars differing in their response to F. culmorum infection. The antifungal activity of methanol extracts obtained from spikes was also evaluated. The tested genotypes differed
significantly in their response to inoculation. The most resistant were Torka and Zebra among common wheat cultivars, and
Weisser Grannenspelz among spelt cultivars. The average content of free phenolic compounds in spikes of spelt and common wheat
was 1246.56 μg g−1 and 1236.58 μg g−1, respectively. The cultivars whose spikes contained the largest amounts of phenols showed the weakest response to F. culmorum infection. No significant differences were observed with regard to peroxidase content, which was 5.22 U g−1 in common wheat spikes and 5.14 U g−1 in spelt spikes. Methanol extracts from spikes of all wheat cultivars contained antifungal substances. The extracts from
spelt spikes inhibited the growth of F. culmorum on PDA to a lesser degree than the extracts from common wheat spikes. This corresponds to the results of field trials, in
which T. spelta generally exhibited a stronger response to F. culmorum infection than common wheat. The high correlation (r = 0.816) between mycelium growth inhibition on the medium and F. culmorum infection indicates that an evaluation of the antifungal activity of extracts from spikes may be used for the selection of
breeding materials directed towards increased resistance to Fusarium head blight. 相似文献
306.
Bases and spaces: resources on the web for accessing the draft human genome - II - After publication of the draft
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Colin AM Semple 《Genome biology》2001,2(6):reviews2001.1-reviews20016
The volume of human genome sequence and the variety of web-based tools to access it continue to grow at an impressive rate, but a working knowledge of certain key resources can be sufficient to get the most from your genome. This article provides an update to Genome Biology 2000, 1(4):reviews2001.1-2001.5. 相似文献