全文获取类型
收费全文 | 75篇 |
免费 | 2篇 |
出版年
2021年 | 1篇 |
2018年 | 2篇 |
2016年 | 1篇 |
2014年 | 4篇 |
2013年 | 7篇 |
2012年 | 1篇 |
2011年 | 1篇 |
2010年 | 5篇 |
2009年 | 4篇 |
2008年 | 3篇 |
2007年 | 2篇 |
2006年 | 2篇 |
2005年 | 4篇 |
2004年 | 1篇 |
2003年 | 1篇 |
2002年 | 1篇 |
2001年 | 2篇 |
1998年 | 2篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1990年 | 1篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 3篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1962年 | 1篇 |
1951年 | 1篇 |
1950年 | 2篇 |
排序方式: 共有77条查询结果,搜索用时 31 毫秒
1.
2.
A comparative study of leaf nutrient concentrations in a regional herbaceous flora 总被引:27,自引:2,他引:27
KEN THOMPSON JOHN A. PARKINSON STUART R. BAND RITA E. SPENCER 《The New phytologist》1997,136(4):679-689
3.
THE BACTERIAL FLORA OF PUGET SOUND FISH 总被引:4,自引:3,他引:1
RITA R. COLWELL 《Journal of applied microbiology》1962,25(2):147-158
4.
RITA COLÓN-URBAN PAUL J. CHEUNG GEORGE D. RUGGIERI ROSS F. NIGRELLI 《Invertebrate reproduction & development.》2013,57(4):245-252
Thirty-two pedunculate barnacles, O. a. geryonophila, were maintained in culture for a period of 2 yr in the laboratory. These barnacles were obtained from the pleopods and mouth parts of the giant marine isopod, Bathynomus giganteus, which had been collected, at a depth of 200 fathoms, in the Gulf of Mexico. The carina, scutum, mandible and maxilla of adult barnacles were typical of deep water species. However, the tergum and labrum were intermediate between those of shallow and deep water species. Adults 3.1–4.1 mm in length were cultured in sea water (15–19°C), and fed on benthic copepods such as Tisbe furcata and Laophonte sp. Three broods of nauplii from 8 barnacles were obtained in 2 yr. Larvae were reared on plankton collected from Coney Island waters in which nauplii reached Stage IV in 10–14 days at 16°C. Isochrysis galbana and Thalassiosira pseudonana individually or in combination maintained nauplii to Stage IV, but with very high mortality. The lack of spines on the carapace edge of the nauplii distinguishes this deep water species from the shallow water form, O. mulleri. 相似文献
5.
In the Calicut population of P. hydrodromous, eyestalk principles are either directly or indirectly involved in maintenance of the differential growth rate of the sexes during the latter half of the first year of the life cycle. The prebreeding season (September—November), which is distinct in crabs 4.0 cm and over in carapace width (cw), is either absent or not distinct in young females (cw 2.8–3.2 cm), though the latter enter their first reproductive cycle by December, when 8–9 mth old. December—March is a period of active vitellogenic growth; from March onwards, there is a distinct swing in favor of somatic growth in females, though the proecdysis per se is not initiated until May. A typical brachyuran, Paratelphusa restricts its reproductive activity to intermolt and somatic growth chiefly to premolt; there are, however, definite phases within the intermolt itself when the physiological tilt favors somatic growth or alternatively reproduction. In females above cw 4.0 cm, the tendency for somatic growth is suppressed once they attain this cw after the monsoon (June—July) molt; eyestalk ablation during the prebreeding season precipitates accelerated ovarian growth. Administration of β-ecdysone in premolt titers failed to restrain this ovarian response and to promote somatic growth sufficiently. Conceivably, gonadal growth-promoting principles keep under check the responsiveness of the target tissues involved in somatic growth perhaps by affecting ecdysone receptors. The present investigations do not indicate a vitellogenesis-inhibiting role for β-ecdysone. 相似文献
6.
RITA S. L. VEIGA ANTONELLA FACCIO ANDREA GENRE CORNÉ M. J. PIETERSE PAOLA BONFANTE MARCEL G. A. van der HEIJDEN 《Plant, cell & environment》2013,36(11):1926-1937
The arbuscular mycorrhizal (AM) symbiosis is widespread throughout the plant kingdom and important for plant nutrition and ecosystem functioning. Nonetheless, most terrestrial ecosystems also contain a considerable number of non‐mycorrhizal plants. The interaction of such non‐host plants with AM fungi (AMF) is still poorly understood. Here, in three complementary experiments, we investigated whether the non‐mycorrhizal plant Arabidopsis thaliana, the model organism for plant molecular biology and genetics, interacts with AMF. We grew A. thaliana alone or together with a mycorrhizal host species (either Trifolium pratense or Lolium multiflorum) in the presence or absence of the AMF Rhizophagus irregularis. Plants were grown in a dual‐compartment system with a hyphal mesh separating roots of A. thaliana from roots of the host species, avoiding direct root competition. The host plants in the system ensured the presence of an active AM fungal network. AM fungal networks caused growth depressions in A. thaliana of more than 50% which were not observed in the absence of host plants. Microscopy analyses revealed that R. irregularis supported by a host plant was capable of infecting A. thaliana root tissues (up to 43% of root length colonized), but no arbuscules were observed. The results reveal high susceptibility of A. thaliana to R. irregularis, suggesting that A. thaliana is a suitable model plant to study non‐host/AMF interactions and the biological basis of AM incompatibility. 相似文献
7.
Life-history traits of lake plankton species may govern their phenological response to climate warming 总被引:1,自引:0,他引:1
A prominent response of temperate aquatic ecosystems to climate warming is changes in phenology – advancements or delays in annually reoccurring events in an organism's life cycle. The exact seasonal timing of warming, in conjunction with species-specific life-history events such as emergence from resting stages, timing of spawning, generation times, or stage-specific prey requirements, may determine the nature of a species' response. We demonstrate that recent climate-induced shifts in the phenology of lake phytoplankton and zooplankton species in a temperate eutrophic lake (Müggelsee, Germany) differed according to differences in their characteristic life cycles. Fast-growing plankton in spring (diatoms, Daphnia ) showed significant and synchronous forward movements by about 1 month, induced by concurrent earlier ice break-up dates (diatoms) and higher spring water temperature ( Daphnia ). No such synchrony was observed for slow-growing summer zooplankton species with longer and more complex life cycles (copepods, larvae of the mussel Dreissena polymorpha ). Although coexisting, the summer plankton responded species specifically to seasonal warming trends, depending on whether the timing of warming matched their individual thermal requirements at decisive developmental stages such as emergence from diapause (copepods), or spawning ( Dreissena ). Others did not change their phenology significantly, but nevertheless, increased in abundances. We show that the detailed seasonal pattern of warming influences the response of phyto- and zooplankton species to climate change, and point to the diverse nature of responses for species exhibiting complex life-history traits. 相似文献
8.
9.
10.
A second member of the Australian endemic genus Australothrips Bagnall (Thripidae: Panchaetothripinae) is described. This species, Australothrips aliceae , was found at sites near Darwin, Northern Territory on the leaves of Calytrix brownii (Myrtaceae). It is of systematic interest because it approaches in structure the members of the palaeotropical genus Phibalothrips Hood that live only on grasses. 相似文献