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71.
Tünde Szmatona-Túri Gábor Magos Diána Vona-Túri Blanka Gál András Weiperth 《Biologia》2018,73(5):523-529
The main objective of this paper is to report habitat occupancy, naturalness status and phenology of Urocoras longispinus (Chyzer and Kulczyński 1897), a little-known spider species. Sampling was conducted in Natura 2000 habitats of the Mátra Mountains, and four disturbed mainroad verges in Hungary between 2012 and 2015. We recorded 356 adult specimens active throughout the year, but abundance was highest in autumn. In the Mátra Mountains shrub removal negatively affected the abundance of U. lonsgspinus: the species preferred shaded habitats. The intensity of mowing maintenance caused changes in the species’ abundance in mainroad verges: the number of individual spiders increased as a result of both without maintenance and enhanced maintenance. We conclude that U. longispinus is a stenochronous spider species which lives in both human-disturbed and undisturbed habitats. However, the nature of the disturbance influenced the abundance of this species to varying degrees. 相似文献
72.
Matthew C. P. Glyn Michaela Egertová Blanka Gazdova Aleš Kovarik Milan Bezdek Andrew R. Leitch 《Chromosoma》1997,106(8):485-492
This paper describes the effects of 5-azacytidine on the condensation state of rye (Secale cereale L.) chromatin introduced into the wheat genome (Triticum aestivum L. cv. Beaver). The wheat cultivar Beaver carries a translocation between the short arm of rye chromosome 1R (1RS) and the
long arm of wheat chromosome 1B (1BL/1RS). 1RS can be detected using genomic in situ hybridisation and carries a ribosomal
DNA (rDNA) locus that can be simultaneously detected using multiple labelling strategies. The rDNA locus divides 1RS into
a distal region that is gene rich and a proximal region that is gene poor and highly methylated. 1RS also carries a large
block of subtelomeric heterochromatin. The drug, which acts to inhibit DNA methylation in plants, has three pronounced effects
on interphase nuclei. (1) It induces aberrant condensation of the rye subtelomeric heterochromatin and in many cases induces
sister chromatid separation in the subtelomeric heterochromatin of G2 nuclei. (2) Nuclei trisomic for 1RS are observed at
low frequency in treated material and are probably a consequence of aberrant sister chromatid separation or condensation.
(3) The drug alters normal condensation of 1RS euchromatin. However, contrary to expectation the effect is not simply to induce
decondensation. The proximal region of the arm actually condenses at low levels of drug administration while the distal region
remains unaltered or increases its decondensation state. Increasing the concentration of 5-azacytidine induces a biphasic
response and at the highest concentration used all regions of the arm show signs of decondensation. Thus the influence of
the drug on chromatin condensation depends on the genomic structure.
Received: 14 July 1997; in revised form: 26 August 1997 / Accepted: 27 August 1997 相似文献
73.
Zdeněk Wimmer Richard Tykva Blanka Bennettová Věra Vlasáková Tomáš Elbert 《Invertebrate neuroscience : IN》1997,3(2-3):193-197
A synthetic insect juvenile hormone analog (a juvenoid), ethylN-[2-[4-[[2,2-(ethylenedioxy)cyclohexyl]methyl]phenox]ethyl]carbamate, which has displayed high biological activity against
different insect species and high stability under field conditions, was selected as a biologically active model compound for
a study of a juvenile hormone analog degradation. The biologically active compound itself and its three diversely radiolabeled
derivatives were applied to the flesh fly (Sarcophaga bullata) or the tsetse fly (Glossina palpalis), respectively. Monitoring of a fate of the applied juvenile hormone analog was carried out using a detection method of the
radioactivity microdistribution within the whole insect body in combination with a radio high performance liquid chromatography
(radio-HPLC), both of whole-body extracts made in different, but in advance scheduled, time intervals, and of extracts of
insect excreta accumulated over an eight-day experiment. 相似文献
74.
Conservation tool or threatening process? management implications of interactions of cattle with vegetation and land at the Vale of Belvoir reserve 下载免费PDF全文
Blanka Tengia Matthew Taylor Jamie Kirkpatrick 《Ecological Management & Restoration》2016,17(2):147-151
A recently purchased private reserve of high conservation value has been grazed in summer by cattle since the early nineteenth century. We ask whether the cattle are causing continuing damage and whether they are necessary to maintain any conservation values. We used five‐year‐old exclosures to determine the effects of cattle on wetland vegetation, mapped damage to soils and landforms and mapped cattle dung deposition in relation to the distributions of rare and threatened plant species. Cattle impacts on wetland plants were minor. Cattle damage to landforms by pugging and bank collapse was frequent near unfenced water bodies. Rare and threatened species were largely on well‐drained ground, while cattle dung was concentrated in wetlands and near water bodies. We conclude that cattle grazing is impacting some conservation values and is not necessary for conservation purposes. Destocking should be accompanied by careful monitoring of threatened plant populations. If necessary, alternative planned disturbances can provide regeneration niches for rare and threatened plants. 相似文献
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Callogenesis was induced in mature embryos. The efficiency of induction and the growth of calli were dependent on 2,4-D concentration. No regeneration of buds or shoots was observed in 720 calli studied, but most calli showed intensive root proliferation on the regeneration medium. Most of the root meristem cells maintained diploid chromosome number. Only a low proportion (about 3.5%) of tetraploid cells was found. No other chromosomal changes were observed. Chromosomal variability does not contribute to the inability of calli derived from mature barley embryos to form buds and shoots. 相似文献
78.
79.
Study of the carbohydrate part of yeast acid phosphatase 总被引:2,自引:0,他引:2
Branko Kozulić Slobodan Barbarić Blanka Ries Pavao Mildner 《Biochemical and biophysical research communications》1984,122(3):1083-1090
It has been found that the carbohydrate part of acid phosphatase from yeast Saccharomyces cerevisiae consists of 16 N-glycosidically linked carbohydrate chains containing from 14 to about 150 mannose units. The presence of very small amounts of O-glycosidically linked chains was indicated. Acetolysis studies pointed to a high similarity in the structure of acid phosphatase and mannan carbohydrate chains. A new method is described for cross-linking of acid phosphatase specifically via carbohydrate chains. The possibility to cross-link the enzyme subunits intramolecularly is in accordance with the suggestion that carbohydrate chains play a role in subunit associations. 相似文献
80.
Blanka Úlehlová 《Folia Geobotanica》1990,25(3):303-308
Changes in chemical composition of autochthonous plant litter undergoing decomposition in litter mesh-bags exposed in a transect across four vegetational zones of a fishpond littoral were estimated during the spring, summer and winter season. The highest decomposition rate was found in all four zones in spring, the lowest one in winter. The decomposition was faster in the two aquatic than in the two terrestrial zones in the spring and the summer season. The litter was enriched with nitrogen and released potassium in all locelities and seasons. The uptake or release of other mineral constituents appeared to be specific for each zone and to depend on the season of the year. 相似文献