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Zabardast T. Buriev Sukumar Saha Ibrokhim Y. Abdurakhmonov Johnie N. Jenkins Abdusattor Abdukarimov Brian E. Scheffler David M. Stelly 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2010,120(3):587-606
MIC-3 is a recently identified gene family shown to exhibit increased root-specific expression following nematode infection of
cotton plants that are resistant to root-knot nematode. Here, we cloned and sequenced MIC-3 genes from selected diploid and tetraploid cotton species to reveal sequence differences at the molecular level and identify
chromosomal locations of MIC-3 genes in Gossypium species. Detailed sequence analysis and phylogenetic clustering of MIC-3 genes indicated the presence of multiple MIC-3 gene members in Gossypium species. Haplotypes of a MIC-3 gene family member were discovered by comparative analysis among consensus sequences across genotypes within an individual
clade in the phylogram to overcome the problem of duplicated loci in the tetraploid cotton. Deficiency tests of the SNPs delimited
six At-genome members of the MIC-3 family clustered to chromosome arm 4sh, and one Dt-genome member to chromosome 19. Clustering was confirmed by long-PCR amplification of the intergenic regions using At-genome-specific MIC-3 primer pairs. The clustered distribution may have been favored by selection for responsiveness to evolving disease and/or
pest pressures, because large variants of the MIC-3 gene family may have been recovered from small physical areas by recombination. This could give a buffer against selection
pressure from a broad range of pest and pathogens in the future. To our knowledge, these are the first results on the evolution
of clustering and genome-specific haplotype members of a unique cotton gene family associated with resistant response against
a major pathogen. 相似文献
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Douglas S. Richmond† Brian A. Kunkel Nethi Somasekhar Parwinder S. Grewal 《Ecological Entomology》2004,29(3):353-360
Abstract. 1. The fungus Neotyphodium lolii forms a symbiotic relationship with its grass host Lolium perenne (perennial ryegrass). The fungus benefits from access to plant nutrients and photosynthate, whereas the plant benefits from acquired chemical defence against herbivory.
2. This study examined the potential for endophyte-mediated plant defences to influence interactions between fall armyworm Spodoptera frugiperda , and the entomopathogenic nematode Steinernema carpocapsae and clarified biological mechanisms underlying the observations made.
3. In laboratory and greenhouse experiments, S. frugiperda larvae were fed endophytic or non-endophytic L. perenne then exposed to S. carpocapsae or injected with the nematodes' symbiotic bacteria Xenorhabdus nematophila .
4. In all instances, S. frugiperda larvae fed endophyte-infected grass suffered significantly lower mortality than those fed non-endophytic plants. Although larvae fed endophyte-infected grass often had significantly lower biomass than those fed uninfected grass, these differences did not account for altered susceptibility to S. carpocapsae .
5. Endophyte-mediated reductions in herbivore susceptibility to the nematode pathogen represent a herbivore adaptation that effectively turns the tables on both plant and natural enemy by reducing the virulence of the nematodes' symbiotic bacteria while expanding the temporal window of herbivory. 相似文献
2. This study examined the potential for endophyte-mediated plant defences to influence interactions between fall armyworm Spodoptera frugiperda , and the entomopathogenic nematode Steinernema carpocapsae and clarified biological mechanisms underlying the observations made.
3. In laboratory and greenhouse experiments, S. frugiperda larvae were fed endophytic or non-endophytic L. perenne then exposed to S. carpocapsae or injected with the nematodes' symbiotic bacteria Xenorhabdus nematophila .
4. In all instances, S. frugiperda larvae fed endophyte-infected grass suffered significantly lower mortality than those fed non-endophytic plants. Although larvae fed endophyte-infected grass often had significantly lower biomass than those fed uninfected grass, these differences did not account for altered susceptibility to S. carpocapsae .
5. Endophyte-mediated reductions in herbivore susceptibility to the nematode pathogen represent a herbivore adaptation that effectively turns the tables on both plant and natural enemy by reducing the virulence of the nematodes' symbiotic bacteria while expanding the temporal window of herbivory. 相似文献
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T J Kreeger A M Faggella U S Seal L D Mech M Callahan B Hall 《Journal of wildlife diseases》1987,23(3):463-470
Adult wolves (Canis lupus) were immobilized with 6.6 mg/kg ketamine hydrochloride (KET) and 2.2 mg/kg xylazine hydrochloride (XYL) administered intramuscularly. Induction time was 4.6 +/- 0.3 min (mean +/- SE). Immobilization resulted in significant bradycardia and hypertension (P less than 0.05). Twenty min after induction, the wolves were given 0.05-0.60 mg/kg yohimbine hydrochloride (YOH). Yohimbine given intravenously produced dose-related increases in heart rate (HR) with doses greater than 0.15 mg/kg resulting in extreme tachycardia (greater than 300 bpm). All doses of YOH caused a temporary decrease in mean arterial blood pressure (MABP) with some individual animals manifesting profound hypotension (less than 30 torr) at doses greater than 0.15 mg/kg. Increasing the dose of YOH above 0.15 mg/kg did not significantly decrease either arousal or ambulation times. Administering YOH at 40 or 60 min after induction resulted in decreased arousal and ambulation times. Stimulation by weighing and taking repeated blood samples during anesthesia did not shorten arousal times. We recommend that wolves immobilized with XYL-KET be antagonized with doses of YOH less than 0.15 mg/kg. 相似文献
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Brian T. Shea 《International journal of primatology》1987,8(2):139-156
In order to understand fully the generally high level of encephalization observed in living primates, we must determine why
early primates exhibited moderately large relative brain sizes compared to their early Tertiary contemporaries. The relatively
high degree of encephalization in early primates may be related at least in part to the fact that they were highly unusualamong mammals in combining a small body size with a strongly precocial reporductive strategy. Other small, precocial mammals
also exhibit moderately high levels of encephalization; but primates appear to have been truly uniquein being the only such small-sized and highly precocial group to give rise to extensive radiations of larger descendants.
This is a key element in understanding primate brain evolution, because the initial “head start” of the early primates was
translated up to larger sizes in descendants. The possible relationships among encephalization, precociality, small size,
and arboreality are discussed, particularly in light of recent debates concerning the validity of the superorder Archonta.
This work emphasizes that we need to consider relative brain size as but one element in a complex synergistic network of morphological
and life-history features. 相似文献