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71.
Tommy J. Rauch 《Environmental Biology of Fishes》2007,78(4):347-351
Interspecific interactions can determine the abundance and distributions of animals. Seaweed blennies, Parablennius marmoreus, and tesselated blennies, Hypsoblennius invemar, are found in barnacle cavities on offshore petroleum platforms in the northern Gulf of Mexico. I measured the interspecific
resource defense interactions between these fishes in aquaria. Seaweed blennies were dominant over tesselated blennies when
equal-sized fishes were tested. No difference in dominance was found when tesselated blennies had a 10% advantage in size.
However, tesselated blennies were able to successfully defend cavities against equal-sized competitors when given the advantage
of prior residence. This prior residence advantage persisted despite seaweed blennies having the advantage of past experience.
Seaweed blennies attain a larger size on petroleum platforms, but empty barnacle cavities are common in this environment.
Tesselated blennies are able to colonize and successfully spawn because they can enter an empty barnacle cavity, gain the
advantage of prior residence, and successfully defend this cavity. 相似文献
72.
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74.
Artificial synthesis of interspecific chimeras between tuber mustard (Brassica juncea) and cabbage (Brassica oleracea) and cytological analysis 总被引:1,自引:0,他引:1
Interspecific chimeras between tuber mustard and red cabbage were obtained by in vitro graft-culture method. Before grafting, 6-day-old seedlings of tuber mustard and red cabbage were vertically half-cut and treated with different concentrations of 6-BA and NAA for 1 min, then, they were symmetrically fit together. As a result, sectorial chimeras were initially produced from the united shoot tips. The maximum frequency of chimeral bud formation reached 6.33% when the vertical sections of tuber mustard and cabbage were treated with 2 mg/l 6-BA and 1 mg/l NAA. When sectorial chimeras were propagated on MS medium containing 1 mg/l 6-BA, periclinal and mericlinal chimeras gradually developed. Chimeral shoots were rooted on half-strength MS medium containing 0.1 mg/l NAA. The rooted chimeras were acclimatized and transferred to the field for cytological and morphological analysis. The results showed that stomata density in the chimeras was significantly higher than that of their parents, while chloroplast size, starch grain size and number were intermediate between the two parents. The chimeras were further analyzed by flow cytometry, and the results indicated that they contained both sets of parental chromosomes. Moreover, chimeral plants possessed valuable characters from the two parents. 相似文献
75.
种间竞争对四种储粮害虫种群动态的影响 总被引:2,自引:0,他引:2
在30 ℃、75 %相对湿度条件下研究种间竞争对玉米象(Sitophilus zeamais)、谷蠹(Rhizopertha domini-ca)、赤拟谷盗(Triboliumcastaneum)和锈赤扁谷盗(Cryptolestes ferrugineus)4种主要储粮害虫种群动态的影响,并对种群动态进行回归分析。结果表明,玉米象与谷蠹、赤拟谷盗与锈赤扁谷盗混合饲养种群增长均受到显著抑制,玉米象和谷蠹对赤拟谷盗和锈赤扁谷盗的种群增长具有明显的促进作用,赤拟谷盗和锈赤扁谷盗对玉米象和谷蠹的种群增长具有一定的抑制作用。回归分析结果表明玉米象种群最大增长潜能最大,锈赤扁谷盗最小,种群增长率变化规律不明显。 相似文献
76.
Root distribution and interactions between intercropped species 总被引:28,自引:0,他引:28
Even though ecologists and agronomists have considered the spatial root distribution of plants to be important for interspecific
interactions in natural and agricultural ecosystems, few experimental studies have quantified patterns of root distribution
dynamics and their impacts on interspecific interactions. A field experiment was conducted to investigate the relationship
between root distribution and interspecific interactions between intercropped plants. Roots were sampled twice by auger and
twice by the monolith method in wheat (Triticum aestivum L.)/maize (Zea mays L.) and faba bean (Vicia faba L.)/maize intercropping and in sole wheat, maize, and faba bean up to 100 cm depth in the soil profile. The results showed
that the roots of intercropped wheat spread under maize plants, and had much greater root length density (RLD) at all soil
depths than sole wheat. The roots of maize intercropped with wheat were limited laterally, but had a greater RLD than sole-cropped
maize. The RLD of maize intercropped with faba bean at different soil depths was influenced by intercropping to a smaller
extent compared to maize intercropped with wheat. Faba bean had a relatively shallow root distribution, and the roots of intercropped
maize spread underneath them. The results support the hypotheses that the overyielding of species showing benefit in the asymmetric
interspecific facilitation results from greater lateral deployment of roots and increased RLD, and that compatibility of the
spatial root distribution of intercropped species contributes to symmetric interspecific facilitation in the faba bean/maize
intercropping.
Electronic Supplementary Material Supplementary material is available for this article at and is accessible for authorized users. 相似文献
77.
Immune system components differ in their functions and costs, and immune defense profiles are likely to vary among species with differing ecologies. We compared adaptive immune defenses in two closely related species that have contrasting inflammatory immune responses, the widespread and abundant house sparrow (Passer domesticus) and the less abundant tree sparrow (Passer montanus). We found that the house sparrow, which we have previously shown mounts weaker inflammatory responses, exhibits stronger adaptive immune defenses, including antibody responses, natural antibody titers, and specific T-cell memory, than the tree sparrow. Conversely, tree sparrows, which mount strong inflammatory responses, also mount stronger nonspecific inflammatory T-cell responses but weaker specific adaptive responses. Prevalence of avian malaria parasite infections, which are controlled by adaptive immune defenses, was higher in the geographically restricted tree sparrow than in the ubiquitous house sparrow. Together these data describe distinct immune defense profiles between two closely related species that differ greatly in numbers and distributions. We suggest that these immunological differences could affect fitness in ways that contribute to the contrasting abundances of the two species in North American and Western Europe. 相似文献
78.
There has been much debate regarding the impact of parasitoid competition and hyperparasitism on the successful biological control of aphid pests. Difficulty in the evaluation of interspecific interactions and trophic links using conventional rearing and dissection methods has prevented a deeper understanding of such relationships. The analysis of trophic links in the parasitoid community associated with the melon aphid (Aphis gossypii) in Hawaii provides a unique opportunity to assess complex interactions that occur in a system where all of the aphids and parasitoids have been introduced. Here, we developed and applied multiplex PCR assays to investigate the occurrence of in-host competition between parasitoids and/or hyperparasitoids on melon aphids collected from fields of Colocasia esculenta. To fully document the parasitoid-hyperparasitoid community within A. gossypii, both live and mummified aphids were examined. A total of 818 live and 245 mummified aphids were analyzed using the multiplex assays, with congruent rearing of over 600 mummified aphids serving as a basis for qualitative comparisons in terms of species composition and trophic linkages. The rearing and the DNA methods showed similar trends, with sharp declines in one parasitoid species followed by sharp increases in another during the course of the season. Molecular analyses revealed that hyperparasitism and multiparasitism of live aphids is remarkably low, whereas hyperparasitism of mummified aphids was extraordinarily high in both rearing and molecular analyses. In comparison to reared samples, molecular analysis of the parasitoid community was more complete and permitted the identification of previously unknown or unconfirmed trophic linkages. The potential of this approach in future studies on the biological control of aphids in Hawaii, particularly in light of new parasitoid introductions, is discussed. 相似文献
79.
Wild rice is a valuable resource for the genetic improvement of cultivated rice (Oryza sativa L., AA genome). Molecular markers are important tools for monitoring gene introgression from wild rice into cultivated rice. In this study, Simple sequence repeat (SSR) markers were used to analyze interspecific hybrids of O. sativa-O. officinalis (CC genome), the backcrossing progenies and the parent plants. Results showed that most of the SSR primers (335 out of 396, 84.6%) developed in cultivated rice successfully amplified products from DNA samples of wild rice O. officinalis. The polymorphism ratio of SSR bands between O. sativa and O. officinalis was as high as 93.9%, indicating differences between the two species with respect to SSRs. When the SSR markers were applied in the interspecific hybrids, only a portion of SSR primers amplified O. officinalis-specific bands in the F(1) hybrid (52.5%), BC(1) (52.5%), and MAALs (37.0%); a number of the bands disappeared. Of the 124 SSR loci that detected officinalis-specific bands in MAAL plants, 96 (77.4%) showed synteny between the A and C-genomes, and 20 (16.1%) showed duplication in the C-genome. Sequencing analysis revealed that indels, substitution and duplication contribute to the diversity of SSR loci between the genomes of O. sativa and O. officinalis. 相似文献
80.
鹅掌楸属种间杂种与亲本花粉壁的超微结构的比较观察 总被引:6,自引:1,他引:5
以杂种鹅掌楸及其亲本中国鹅掌楸(Liriodendron chinense)和北美鹅掌楸(L.tulipifera)为材料,研究花粉形状及花粉壁的超微结构.结果表明,杂种与亲本间花粉壁超微结构具有明显的差异,它们可作为种间及杂种与亲本的识别与区分的依据.从杂种鹅掌楸与双亲的花粉壁的纹饰的遗传关系来看,前者花粉壁表面皱疣状隆起的纹饰表明,北美鹅掌楸花粉壁纹饰特征在杂种鹅掌楸中得到充分表现. 相似文献