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41.
《Journal of Natural History》2012,46(6):705-715
In semi-arid Iberian ecosystems, the dung beetle community associated with rabbit dung heaps shows high complexity in spite of adverse factors, such as the low water and nutritional content of rabbit pellets and the arid climate of environments. A total of 24 species showing optional telecoprid, paracoprid and endocoprid (including kleptocoprid) patterns were studied. Acquisition of many morphological adaptations from aridity (flightlessness), exploitation of dry dung (mouthpart modifications) and behavioural specializations are described. These adaptations may explain the exploitation of dry dung and the high rate of endemism observed in the dung beetle community studied. All morphological and behavioural specializations described can be considered as derived characters for the exploitation of fibrous and dry dung, showing a secondary evolutionary line that suggests the return of these beetles to saprophagy. 相似文献
42.
《Journal of Natural History》2012,46(19-20):1405-1408
It is widely accepted that Mesozoic ecosystems were basically similar to Cenozoic ecosystems and it has been proposed that the role of dung‐beetles in those ecosystems was identical to that of today, but the dung of dinosaurs were used as a source of food instead of the dung of mammals. While dinosaurs have been known since Triassic, Scarabeids are present in the fossil records probably since Lower Jurassic. But a very important metabolic feature of dinosaurs has not been taken into account, the connection between digestive and uro‐genital systems. So here we propose the hypothesis that coprophagy in dung‐beetles has been associated, since it began, with mammals. 相似文献
43.
《Journal of Natural History》2012,46(11-12):691-698
Anti-herbivory animal mimicry by plants has been paid scant attention, and as a result additional types are expected to be recognized. Lycium chinense plants growing in Japan have dark axils, and many leaf-eating beetles leave faeces on host plants or use their faeces as defence. The dark axils of Lycium chinense mimic poisonous faeces or faeces-covered larvae of the leaf beetle Lema decempunctata, which may result in reduced herbivory by mammalian and insect herbivores. Field work in the very different flora of Israel revealed that the same morphology/colouration exists in various wild plant species, both monocotyledons and dicotyledons. We therefore propose a new type of beetle and beetle faeces defensive plant mimicry, and suggest that this type of putative defensive mimicry against mammalian and insect herbivores is probably a widespread but overlooked phenomenon. Moreover, such mimicry may also attract visually oriented enemies that can attack various invertebrate herbivores that occupy these plants. 相似文献
44.
《Journal of Natural History》2012,46(17):2225-2249
Dung beetle guilds of different competitive level coexist at high abundances in the forest–savanna mosaic of Ivory Coast. A total of 25?875 specimens was recorded from 90 samples of fresh buffalo dung exposed for 4-h periods over the day in the Parc National de la Comoé. Redundancy analyses show different patterns of the guild structure determined by time of day, and positive correlations of guild abundance with temperature. The competitively superior telecoprids (rollers) have their abundance peak at midday when the high temperatures presumably enable them to perform their energetically costly rolling behaviour at greater speed. The competitively intermediate paracoprids (tunnellers) and the competitively inferior endocoprids (dwellers) have their peak around dusk when: (1) the superior competitors are not active, and (2) they can easily synchronize their flight activity using light intensity changes. During the two peaks of flight activity of the dung beetles, their abundance at the resource is very high, causing obvious competition. On the other hand, the resource is hardly used between 22:00?h and 10:00?h. This is probably due to physiological constraints (high optimum temperature required for the diurnal species and dependence on light intensity patterns as a flight trigger of the nocturnal species, respectively). Shifting flight activity to these periods of low competition does not occur, resulting in a unequal level of competition over the day, thus periods of considerable competition within dung beetle assemblages alternate with vacant temporal refuges. 相似文献
45.
本文通过现场观摩比赛法、录像资料法、访问法等对我国在近几届举办的全国水中健身比赛中的成绩进行整理和分析,从中得出水中健身运动在近十年来的发展和变化,并提出了一些看法和建议,以期为我国水中健身运动的发展提供一点帮助。 相似文献
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48.
Widespread non-marine Mesozoic deposits in China often contain abundant cupedomorpha fossils with significance for correlation. Based on the composition and characteristics of the cupedomorphs, at present, seven cupedid and ommatid assemblages are recognized from the Jurassic-Cretaceous rocks, of which three cupedid and two ommatid assemblages were recovered from North and northeast China: Middle Jurassic Tetrocupes-Hebeicupes cupedid assemblage from northern Hebei and Inner Mongolia (Yanliao fauna); Late Jurassic or Early Cretaceous Ovatocupes-Priacma cupedid and Amblomma-Sinocupes ommatid assemblages from western Liaoning (Jehol fauna); Early Cretaceous Lupicupes-Diluticupes cupedid and Monticupes ommatid assemblages from Beijing and adjacent areas. Both the Ovatocupes-Priacma and AmblommaSinocupes assemblages are important elements of the Jehol entomofauna. Remaining are the Late Jurassic or Early Cretaceous MesotricupesGansucupes cupedid assemblage from Jiuquan Basin, Gansu Province, NW China and the ForticupesPicticupes ommatid assemblage from Shandong Province. In southern China only one poorly preserved ommatid specimen, Zygadenia (=Notocupes) sp. occurs. 相似文献
49.
拉萨河是雅鲁藏布江的主要支流之一,是拉萨河流域广大居民最主要的生产和生活用水的水源。对于拉萨河流域经济社会的发展具有十分重要的作用,拉萨河流域水质质量的好坏直接影响着流域几十万居民的生产、生活质量和安全。但是,随着拉萨河流域采矿、选矿等矿产业的快速发展,在带来巨大经济利益的同时,它们排放的废弃物直接或者间接地影响着拉萨河流域生态环境质量,应该引起大家的高度重视。文章通过对拉萨河流域选矿厂的分布情况以及河段水质指标的调查研究,发现目前为止拉萨河流域水质没有受到污染,但是随着流域经济社会的进一步发展,不可避免地会对拉萨河流域水体产生污染。 相似文献
50.
9种拟步甲16S rDNA部分序列及其亲缘关系 总被引:6,自引:0,他引:6
测定了9种拟步甲的16S rDNA部分基因序列,并与GenBank中的1种步甲的基因序列作同源性比较,计算其核苷酸使用频率并构建了分子系统树.在获得的435 bp的序列中,A+T约占74.4%,颠换(transversion)取代的速率大于转换(transition)取代的速率,其中277个核苷酸位点存在变异.结果表明:属内种间的碱基序列差异范围为3.4%~6.2%;族内属间为9.4%~11.0%;科内族间为10.8%~17.7%;科与科间的差异达到46.7%~50.3%.分子系统树表明:拟步甲科为一单系群,其中琵甲族较为进化,漠甲族与漠王族相对原始;琵甲族与土甲族的亲缘关系较近;漠甲族、漠王族与鳖甲族的亲缘关系较近.本结果与传统的分类观点相吻合. 相似文献