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871.
Production of Trichoderma strains with pesticide-polyresistance by mutagenesis and protoplast fusion 总被引:1,自引:0,他引:1
Hatvani L Manczinger L Kredics L Szekeres A Antal Z Vágvölgyi C 《Antonie van Leeuwenhoek》2006,89(3-4):387-393
The sensitivity of two cold-tolerant Trichoderma strains belonging to the species T. harzianum and T.␣atroviride was determined to a series of pesticides widely used in agriculture. From the 16 pesticides tested, seven fungicides: copper sulfate, carbendazim, mancozeb, tebuconazole, imazalil, captan and thiram inhibited colony growth of the test strains significantly with minimal inhibitory concentrations of 300, 0.4, 50, 100, 100, 100 and 50 g/ml, respectively. Mutants resistant to carbendazim and tebuconazole were produced from both wild type strains by means of UV-mutagenesis. The cross-resistance capabilities and in␣vitro antagonistic properties of the mutants were determined. Carbendazim-resistant mutants showed total cross-resistance to benomyl and thiabendazole at a concentration of 20 g/ml. Intraspecific protoplast fusion was carried out between carbendazim- and tebuconazole-resistant mutants of both parental strains, and putative haploid recombinants with stable resistance to both pesticides were produced in the case of T.␣atroviride. These pesticide-polyresistant progenies are potential candidates for application in an integrated pest management system.This work was presented as an oral lecture in section ‘Agriculture, Soil, Forest Microbiology’ at the BioMicroWorld2005 conference. 相似文献
872.
The results of 11 experiments with Drosophila species show that fertility is not a reducible property: the fertility of a mating pair cannot be predicted from the average fertility of the two genotypes involved. We propose a model of fertility selection that does not assume additivity (or multiplicativity) but assumes random mating and that the genotypic frequencies are in Hardy-Weinberg equilibrium. Numerical simulations show that removal of the assumption of Hardy-Weinberg frequencies does not significantly change the equilibrium frequencies predicted by the model. 相似文献
873.
J M Gandarias L Casis R Múgica G Aréchaga M Ramírez 《Revista Espanola de Fisiología》1989,45(1):89-93
A comparative study of brain aminopeptidase activity between 18 month old male rats and young adults of 3 months has been carried out utilizing the arylamides Leu-, Arg-, Lys-, Tyr- and Asp-beta-naphthylamide as substrates. Statistical analysis of results showed no significant differences either in areas studied or for enzymatic activities detected when both ages were compared. Two different patterns of regional distribution of enzymatic activity were observed: One came to be as a result of the use of Lys-, Arg-, Leu- or Tyr-beta-naphthylamide and the other as a result of the use of Asp-beta-naphthylamide. 相似文献
874.
Using solution NMR spectroscopy, three-dimensional structures have been obtained for an 18-residue synthetic polypeptide fragment of 18.5 kDa myelin basic protein (MBP, human residues Q81-T98) under three conditions emulating the protein's natural environment in the myelin membrane to varying degrees: (a) an aqueous solution (100 mM KCl pH 6.5), (b) a mixture of trifluoroethanol (TFE-d2) and water (30 : 70% v/v), and (c) a dispersion of 100 mM dodecylphosphocholine (DPC-d38, 1 : 100 protein/lipid molar ratio) micelles. This polypeptide sequence is highly conserved in MBP from mammals, amphibians, and birds, and comprises a major immunodominant epitope (human residues N83-T92) in the autoimmune disease multiple sclerosis. In the polypeptide fragment, this epitope forms a stable, amphipathic, alpha helix under organic and membrane-mimetic conditions, but has only a partially helical conformation in aqueous solution. These results are consistent with recent molecular dynamics simulations that showed this segment to have a propensity to form a transient alpha helix in aqueous solution, and with electron paramagnetic resonance (EPR) experiments that suggested a alpha-helical structure when bound to a membrane [I. R. Bates, J. B. Feix, J. M. Boggs & G. Harauz (2004) J Biol Chem, 279, 5757-5764]. The high sensitivity of the epitope structure to its environment is characteristic of intrinsically unstructured proteins, like MBP, and reflects its association with diverse ligands such as lipids and other proteins. 相似文献
875.
876.
Henry F. Howe Yuliana Urincho-Pantaleon Marinés de la Peña-Domene Cristina Martínez-Garza 《Oecologia》2010,164(3):731-740
We explore processes of seed immigration and seedling recruitment before an experimental rainforest restoration matures enough
to affect either. Twenty-four 30 × 30-m plots were fenced in 12 ha of pasture in 2006. Seeds were collected in ninety-six
1-m−2 seed traps; recruits were censused in ~12,000 m2 in which establishment was allowed. We tested effects of distance from forest, living trees, and stumps of trees cut during
site preparation on seed rain in 2007 and effects of these and soil depth on recruits through June 2008. Seed fall and recruitment
were not correlated with distance to forest 90–400 m away, nor to living shade trees outside the 160 × 485-m experimental
grid. Recruitment differed for animal- and wind-dispersed species in a topographically complex landscape. Recruitment of wind-dispersed
species was random with respect to soil depth or distance to recent stumps. Recruitment of animal-dispersed species was multimodal;
partial correlations with number of stumps within 30 m of plots were significant with soil depth held constant (P < 0.025), as were correlations of recruitment with soil depth with number of stumps held constant (P < 0.01). Animal-dispersed recruits were often not conspecifics of adults that had been cut, indicating a legacy of attraction
by fruiting trees of animals bearing seeds from distant sources. Ecological implications are that recruitment in pastures
released from grazing reflects a mix of widely scattered wind-dispersed pioneers and, where animal-dispersed trees exist,
multi-modal and decidedly non-random recruitment of pioneer and later successional animal-dispersed trees from seed banks. 相似文献
877.
Juan Jesús Molina-Rueda María Belén Pascual Francisco M. Cánovas Fernando Gallardo 《Planta》2010,232(6):1471-1483
Glutamate decarboxylase (GAD, EC 4.1.1.15) is a key enzyme in the synthesis of γ-aminobutyric acid (GABA) in higher plants.
A complete cDNA encoding glutamate decarboxylase (GAD, EC 4.1.1.15) was characterized from Pinus pinaster Ait, and its expression pattern was studied to gain insight into the role of GAD in the differentiation of the vascular system.
Pine GAD contained a C-terminal region with conserved residues and a predicted secondary structure similar to the calmodulin
(CaM)-binding domains of angiosperm GADs. The enzyme was able to bind to a bovine CaM-agarose column and GAD activity was
higher at acidic pH, suggesting that the pine GAD can be regulated in vivo by Ca2+/CaM and pH. A polyclonal antiserum was prepared against the pine protein. GAD expression was studied at activity, protein,
and mRNA level and was compared with the expression of other genes during the differentiation of the hypocotyl and induction
of reaction wood. In seedling organs, GABA levels closely matched GAD expression, with high levels in the root and during
lignification of the hypocotyl. GAD expression was also induced in response to the production of compression wood and its
expression matched the pattern of other genes involved in ethylene and 2-oxoglutarate synthesis. The results suggest of a
role of GAD in hypocotyl and stem development in pine. 相似文献
878.
Paulo Silva Arnoldo R. Façanha Rui M. Tavares Hernâni Gerós 《Journal of Plant Growth Regulation》2010,29(1):23-34
Populus euphratica has been used as a plant model to study resistance against salt and osmotic stresses, with recent studies having characterized
the tonoplast and the plasma membrane ATPases, and two Na+/H+ antiporters, homologs of the Arabidopsis tonoplast AtNHX1, were published in databases. In the present work we show that P. euphratica suspension-cultured cells are highly tolerant to high salinity, being able to grow with up to 150 mM NaCl in the culture
medium without substantial modification of the final population size when compared to the control cells in the absence of
salt. At a salt concentration of 300 mM, cells were unable to grow but remained highly viable up to 17 days after subculture.
The addition of a 1-M-NaCl pulse to unadapted cells did not promote a significant loss in cell viability within 48 h. In tonoplast
vesicles purified from cells cultivated in the absence of salt and from salt-stressed cells, vacuolar H+-pyrophosphatase (V-H+-PPase) seemed to be the primary tonoplast proton pump; however, there appears to be a decrease in V-H+-PPase activity with exposure to NaCl, in contrast to the sodium-induced increase in the activity of vacuolar H+-ATPase (V-H+-ATPase). Despite reports that in P. euphratica there is no significant difference in the concentration of Na+ in the different cell compartments under NaCl stress, in the present study, confocal and epifluorescence microscopic observations
using a Na+-sensitive probe showed that suspension-cultured cells subject to a salt pulse accumulated Na+ in the vacuole when compared with control cells. Concordantly, a tonoplast Na+/H+ exchange system is described whose activity is upregulated by salt and, indirectly, by a salt-mediated increase of V-H+-ATPase activity. 相似文献
879.
Márta Molnár-Láng András Cseh Éva Szakács István Molnár 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2010,120(8):1535-1545
The main objective of the present work was to develop a wheat genotype containing both the recessive crossability alleles
(kr1kr1kr2kr2), allowing high crossability between 6x wheat and diploid rye, and the 1BL.1RS wheat/rye translocation chromosome. This wheat
genotype could be used as a recipient partner in wheat–rye crosses for the efficient introduction of new allelic variation
into 1RS in translocation wheats. After crossing the wheat cultivars ‘Mv Magdaléna’ and ‘Mv Béres’, which carry the 1BL.1RS
translocation involving the 1RS chromosome arm from ‘Petkus’, with the line ‘Mv9 kr1’, 117 F2 plants were analysed for crossability, ten of which had higher than 50% seed set with rye and thus presumably carried the
kr1kr1kr2kr2 alleles. Four of the ten plants contained the 1BL.1RS translocation in the disomic condition as detected by genomic in situ
hybridization (GISH). The wheat × rye F1 hybrids produced between these lines and the rye cultivar ‘Kriszta’ were analysed in meiosis using GISH. 1BL.1RS/1R chromosome
pairing was detected in 62.4% of the pollen mother cells. The use of fluorescent in situ hybridization (FISH) with the repetitive
DNA probes pSc119.2, Afa family and pTa71 allowed the 1R and 1BL.1RS chromosomes to be identified. The presence of the 1RS
arm from ‘Kriszta’ besides that of ‘Petkus’ was demonstrated in the F1 hybrids using the rye SSR markers RMS13 and SCM9. In four of the 22 BC1 progenies analysed, only ‘Kriszta’-specific bands were observed with these markers, though the presence of the 1BL.1RS translocation
was detected using GISH. It can be concluded that recombination occurred between the ‘Petkus’ and ‘Kriszta’ 1RS chromosome
arms in the translocated chromosome in these plants. 相似文献
880.
Gómez-Olivencia A Carretero JM Lorenzo C Arsuaga JL Bermúdez de Castro JM Carbonell E 《Journal of human evolution》2010,59(6):620-640
The Lower Pleistocene TD6 level at the Gran Dolina site in the Sierra de Atapuerca (Burgos, Spain) has yielded nine ribs that represent a minimum of three individuals of the species, Homo antecessor. We present a detailed morphological and metric study of these costal elements, including the siding and anatomical position of all of the rib remains. The adult or nearly adult ribs are also metrically compared with other fossil hominins and with modern comparative samples. The costal elements recovered to date from the TD6 level at Gran Dolina can neither confirm nor reject the hypothesis that H. antecessor had a large thorax, similar to that of Neandertals. However, the fragmentary evidence of the H. antecessor thoracic skeleton is not inconsistent with this suggestion based on other skeletal elements, such as clavicles.