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81.
Eight new species in seven new genera of follicular fruits are described from the Late Cretaceous of southern Sweden. They are Agapitocarpus emisxus , Chontrocarpus pachytoichus , Maiandrocarpus moirasmenus , Malliocarpus batrachoides , Mitocarpus elegans , Xylocarpus rhitidoides , Zeugarocarpus adroagathus and Z. leptoagathus . The fossil follicles are borne along infructescence axes or more commonly occur as isolated, dispersed fruits. Three genera, Maiandrocarpus , Mitocarpus and Zeugarocarpus , have follicles in distinct pairs borne spirally on an infructescence axis. Each follicle of a pair faces the axis with its ventral slit, which strongly indicates that the paired follicles were derived from two separate, monocarpellate flowers rather than from a single, bicarpellate flower. One genus ( Malliocarpus ) has follicles borne individually in the infructescence and three others ( Agapitocarpus , Chontrocarpus and Xylocarpus ) are known only as dispersed follicles. The paired follicles share many features with most of the dispersed follicles, including a sessile stigmatic area, a three-layered simple follicle wall, a simple vascular system composed of one dorsal and two lateral bundles, as well as a marginal-linear placentation bearing several anatropous ovules. Accordingly they are thought to belong to the same complex of taxa. The general structure of the fossils and comparison with modern angiosperms suggest that the fossils might represent an extinct lineage within or close to basal eudicots and many characters are shared with members of extant Proteaceae.  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 148 , 377–407.  相似文献   
82.
A genomic library from the commercial diploid cultivar ‘Ouro’ (Musa acuminata), enriched for CT‐ and GT‐repeats, was used to isolate and characterize 23 microsatellite loci. These loci were tested in 10 Musa genotypes, representing various Musa genomic groups with distinct ploidy level. The number of alleles per locus ranged from one to seven, and 20 loci were highly informative. Four loci appeared to amplify B genome‐specific alleles, while three loci seemed to be absent in the B genome. The polymorphism revealed by these loci will be extremely useful for genetic mapping, marker‐assisted selection, germplasm characterization and evolutionary studies in Musa.  相似文献   
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STATUS OF GIANT CLAM RESOURCES OF THE PHILIPPINES   总被引:1,自引:0,他引:1  
Field surveys were conducted to determine distribution and abundanceof giant dam resources in the Philippines. All seven known speciesof giant clams were recorded with Tridacna crocea, T. maximaand T. squamosa occurring the most frequently. The larger speciesT. derasa, T. gigas, Hippopus hippopus and H. porcellanus wererelatively rare. The reduction of giant dam stocks in the Philippines is dueto the uncontrolled exploitation of this resource which is primarilygathered for shellcraft and as supplementary diet in coastalvillages. (Received 26 February 1988; accepted 6 July 1988)  相似文献   
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Inbreeding is expected to increase the variability in size and shape within populations. The distinct effects of inbreeding on size and shape suggest that they are governed by different developmental pathways. One unresolved question is whether the non‐allometric shape component is partially unconstrained developmentally and therefore whether shape is evolvable. In the present study, we utilized a mass outbred population of Drosophila melanogaster maintained at standard laboratory conditions. Eight lines with equivalent expected levels of inbreeding (F ≈ 0.67) were obtained by restricting the size of each population to two pairs for nine generations. Nine landmarks were measured on Drosophila wings of the inbreed lines and compared with those of the mass population. Wing landmarks comprise an excellent model system for studying evolution of size and shape. Landmark measurements were analyzed with a Procrustes generalized least squares procedure. To visualize global shape changes among samples, we reconstructed the mean shape and the shape changes related to both the allometric and non‐allometric components. An increased variability in the non‐allometric shape component was found with inbreeding. This indicated that shape was not entirely developmentally constrained, and therefore that shape appears to be evolvable. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 102 , 626–634.  相似文献   
88.
Secondary metabolism plant glycosyltransferases (UGTs) ensure conjugation of sugar moieties to secondary metabolites (SMs) and glycosylation contributes to the great diversity, reactivity and regulation of SMs. UGT73B3 and UGT73B5, two UGTs of Arabidopsis thaliana (Arabidopsis), are involved in the hypersensitive response (HR) to the avirulent bacteria Pseudomonas syringae pv. tomato (Pst‐AvrRpm1), but their function in planta is unknown. Here, we report that ugt73b3, ugt73b5 and ugt73b3 ugt73b5 T‐DNA insertion mutants exhibited an accumulation of reactive oxygen species (ROS), an enhanced cell death during the HR to Pst‐AvrRpm1, whereas glutathione levels increased in the single mutants. In silico analyses indicate that UGT73B3 and UGT73B5 belong to the early salicylic acid (SA)induced genes whose pathogen‐induced expression is co‐regulated with genes related to cellular redox homeostasis and general detoxification. Analyses of metabolic alterations in ugt mutants reveal modification of SA and scopoletin contents which correlate with redox perturbation, and indicate quantitative modifications in the pattern of tryptophan‐derived SM accumulation after Pst‐AvrRpm1 inoculation. Our data suggest that UGT73B3 and UGT73B5 participate in regulation of redox status and general detoxification of ROS‐reactive SMs during the HR to Pst‐AvrRpm1, and that decreased resistance to Pst‐AvrRpm1 in ugt mutants is tightly linked to redox perturbation.  相似文献   
89.
Abstract.  1. Analyses of ecological trade-offs help to explain how organisms balance competing demands. Harvester ants ( Pogonomyrmex occidentalis ), are conspicuous residents of shortgrass prairie in western North America; worker P. occidentalis actively clear all vegetation from the immediate vicinity of their large gravel mounds. This study is based on the prediction that vegetation clearing yields a thermal trade-off by increasing soil temperatures; during cool periods the resulting increase in soil temperature opens new time windows for activity, while during hot periods the soil temperature is more likely to exceed the maximum thermal tolerance for this species. To test the hypothesis that daily and seasonal trade-offs in ant activity result from vegetation removal, the effects of experimentally applied shade on activity patterns were measured.
2. Harvester ant activity correlated highly with ground temperature; experimental shading of ant mounds shifted daily activity patterns by lowering ground temperature. Shading in the morning significantly delayed the onset of ant activity by preventing solar warming of the mound. In contrast, mid-day experimental shading prevented elevation of ground temperatures to above 50 °C and allowed ants to remain active when lethally high temperatures would normally force them inside the mound.
3. A model derived from field data predicted surface ground temperature (and therefore ant activity) based on air temperature and solar radiation, under conditions of sun and shade. For each of six seasons modelled, shade removal yielded a net gain of activity time. These results indicate that vegetation removal by harvester ants produces an advantageous thermoregulatory effect by helping to maximise activity time.  相似文献   
90.
Abstract.  The Brazilian apple leafroller, Bonagota cranaodes (Meyrick) (Lepidoptera: Tortricidae) is reared in the laboratory under a long-day (LD 14 : 10 h) and a short-day (LD 7 : 17 h) photoperiod at 22 °C, and under two different temperatures (10–13 °C and 21–22 °C). The development time from larval to adult eclosion do not differ between the two photoperiods, but did between the two temperature regimes. However, the larvae do not enter diapause, even under short day conditions and low temperatures. The number of adults obtained does not differ with temperature and light conditions. Field captures with pheromone traps show that Brazilian apple leafroller occurs in apple orchards throughout the year and the population densities are lower in winter. Accordingly, control measures should be taken during the off-season.  相似文献   
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