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661.
Upland cotton (Gossypium hirsutum L.) can move leaves to track the sun throughout the day, so-called leaf diaheliotropic movement. This paper reports an experimental
test of the hypothesis that leaf diaheliotropic movement in upland cotton can enhance carbon assimilation and not increase
the risk of stress from high energy load. In this experiment, cotton leaves were divided into two groups: one was that leaves
could track the sun freely; another was that leaves were retained to the horizontal position. The diaheliotropic leaves recorded
higher incident irradiance than the restrained ones, especially in the morning and late afternoon. Compared with restrained
leaves, diaheliotropic leaves were generally warmer throughout the day. As expected, diaheliotropic leaves had significantly
higher diurnal time courses of net photosynthetic rate (P
N) than restrained leaves, except during 14:00–18:00 of the local time. Higher instantaneous water-use efficiency (WUE) was
observed in diaheliotropic leaves in the early morning and late afternoon than in the restrained leaves. During the given
day, diaheliotropic and restrained leaves had similar diurnal time courses of recovery of maximal quantum yield of PSII photochemistry
(Fv/Fm). Diaheliotropic leaves recorded lower or similar photochemical quenching coefficient (qp) than restrained leaves did throughout the day. These results suggest that cotton leaf diaheliotropic movement can improve
carbon gain and water use efficiency and not intensify photoinhibition. 相似文献
662.
663.
A.-R. Jang J.-S. Park D.-K. Kim J.-Y. Park J.-H. Ahn D.-Y. Kim T.-S. Lee J.-Y. Chang J.-H. Choi J.-H. Park 《Letters in applied microbiology》2021,73(3):383-391
This study was conducted to investigate the inhibitory effects of the cell-free culture supernatant of Lactobacillus curvatus Wikim 38 (LC38-CS) on RANKL-induced osteoclast differentiation and bone loss in a mice model of ovariectomy-induced post-menopausal osteoporosis. LC38-CS inhibited the RANKL-induced differentiation of bone marrow-derived macrophages (BMDMs) into osteoclasts in a dose-dependent manner. F-actin ring formation and bone resorption were also reduced by LC38-CS treatment of RANKL-treated BMDMs. In addition, LC38-CS decreased the RANKL-induced activation of the TRAF6/NF-κB/MAPKs axis at the early stage and the expression of osteoclastogenesis-related genes in BMDMs treated with RANKL. PRMT1 and ADMA levels, new biomarkers for osteoclastogenesis, were decreased by LC38-CS treatment. The administration of LC38-CS increased bone volume and bone mineral density in ovariectomized mice in μ-CT analysis. These findings suggest that LC38-CS inhibited RANKL-induced osteoclast differentiation by the downregulation of molecular mechanisms and exerted anti-osteoporotic effects. 相似文献
664.
Blue cone monochromatism (BCM) is a rare X-linked colour vision disorder characterized by the absence of both red and green
cone sensitivity. Most mutations leading to BCM fall into two classes of alterations in the red and green pigment gene array
at Xq28. In one class the red and green pigment genes are inactivated by deletion in the locus control region. In the second
class genetic rearrangements have created an isolated pigment gene that carries an inactivating point mutation. Here we describe
a clinical case of BCM caused by a new mutation where exon 4 of an isolated red pigment gene has been deleted. The finding
represents the first intragenic deletion yet described among red and green pigment genes.
Received: 29 December 1995 / Revised: 30 May 1996 相似文献
665.
666.
D. Chandler S. Tinschert K. Lohan K. Harrop J. Goldblatt M. Nagy S. Hummel H.-S. Braun N. Laing P. Nürnberg 《Human genetics》2001,108(5):394-397
Craniometaphyseal dysplasia--Jackson type (CMDJ) is an autosomal dominant bone dysplasia with hyperostosis and sclerosis of the skull and abnormal modelling of the metaphyses. In a large German pedigree, a locus for CMDJ has been mapped previously to the short arm of chromosome 5 (5p15.2-p14.1), defining a 19-cM disease interval between markers D5S2004 and D5S502. Analysis of a large Australian pedigree together with a second German family confirms linkage to the same region. Obligate recombinations in the new families and confirmation of a supposed recombination in the previously reported German kindred have enabled us to narrow the critical region down to approximately 4 cM between markers D5S1987 and D5S1991. 相似文献
667.
668.
B.-S. Lee T. Maurer H. R. Kalbitzer E. Holler 《Applied microbiology and biotechnology》1999,52(3):415-420
β-Poly(l-malate) (PMLA) production in Physarum polycephalum has been followed by using d-[1-13C]glucose and Ca13CO3. Nuclear magnetic resonance studies of PMLA showed that the 13C label from [1-13C]glucose was incorporated in the presence of CaCO3 into positions C-3 (-CH2-) and C-4 (-CO-) of the l-malate repeating unit of PMLA. The 13C label from Ca13CO3 was incorporated into position C-4 and indicated that not only the endogenous CO2 but also the exogenous CO2 from CaCO3 served significantly as a carbon source for PMLA production. In the absence of CaCO3, the 13C labeling pattern of PMLA from d-[1-13C]glucose was almost indistinguishable from that for the natural abundance 13C-NMR spectrum of the polymer. These results indicated that l-malate used for PMLA production is synthesized either via carboxylation of pyruvate and reduction of oxaloacetate in the
presence of CaCO3 or via the oxidative tricarboxylic acid (TCA) cycle in the absence of CaCO3. Avidin strongly inhibited the formation of l-malate via carboxylation; the 13C labeling pattern of PMLA in the presence of CaCO3 was almost identical with that for the natural abundance spectrum when avidin was added, indicating that l-malate utilized for PMLA production was supplied under this condition by the oxidative TCA cycle.
Received: 16 March 1999 / Received revision: 5 May 1999 / Accepted: 7 May 1999 相似文献
669.
B.-B. Fan S. Yusup S. Sundberg Y.-D. Chen H.-X. Qiao S.-S. Liu Z.-J. Bu 《Plant biology (Stuttgart, Germany)》2023,25(3):440-447
- Dry/wet cycling driven by water level fluctuation in wetlands may strongly influence the destiny of seeds. However, how dry/wet cycling affects spore survival and germinability in peatland bryophytes is poorly understood.
- Six peatland bryophytes, three hummock- and three hollow-dwelling Sphagnum species, were chosen as study species. We tested the effects of dry (60% air RH)/wet (waterlogging) cycle frequency (once per 12, 8 or 4 days for low, medium or high, respectively) and ratio (3:1, 1:1 or 1:3 dry:wet time per cycle) on spore germinability, viability, dormancy percentage and protonema development.
- Dry/wet cycling significantly reduced spore germination percentage and viability and slowed protonema development in all Sphagnum species, being more pronounced with higher dry/wet cycling frequencies. The hummock species S. capillifolium and S. fuscum had higher spore germination percentage after the continuous dry treatment, while the hollow species S. angustifolium, S. squarrosum and S. subsecundum showed the opposite response, compared to the continuously wet treatment. Except for S. squarrosum, spore viability was higher after the dry than after the wet treatment. Spore viability and dormancy percentage were higher after a dry/wet ratio of 1:3 than after ratios of 3:1 and 1:1.
- Our study shows that both germinability and viability of bryophyte spores are reduced by dry/wet cycling (especially when frequent) in peatlands. This emphasizes the need to ensure constant water levels and low frequencies of water level fluctuation, which are relevant in connection with wetland restoration, to promote Sphagnum spore survival and establishment in peatlands after disturbances.
670.
J. S.-M. Tschen C.-S. Chen C.-C. Hsue Y.-L. Ling Y.-H. Cheng 《Journal of Phytopathology》1997,145(8-9):363-369
Thirteen Rhizoctonia solani isolates belonging to anastomosis group four were examined. All of the isolates carry plasmids except isolates CHU344 and CHU345. Plasmids were analysed by agarose gel electrophoresis and observed by transmission electron microscope. The plasmid DNA is linear, having a size of 2.6 kbp. The termini of the plasmid have a hairpin structure. The replication of plasmid DNA of R. solani CHU341 (pCHU341) was demonstrated by electron microscopy.
Virulence of the fungi was tested on radish seedlings and expressed according to percentage of radish seedlings that damped-off. Strains CHU341, CHU344, CHU345, CHU346, CHU347, CHU348, CHU350 and CHU353, suppressed damping-off of radish seedlings by the virulent isolates, CHU342, CHU349, CHU351 or CHU352 and was expressed according to a suppressiveness index. The chitinase activities of radish seedlings increased from 10 to 20 times after inoculation with suppressive isolates, CHU341, CHU344 and CHU345.
The results indicate that damping-off of radish seedlings caused by R. solani can be protected by related strains with or without plasmids. The protection of the seedlings may result from the enhancement of chitinase activities induced by the suppressive strains of R. solani. 相似文献
Virulence of the fungi was tested on radish seedlings and expressed according to percentage of radish seedlings that damped-off. Strains CHU341, CHU344, CHU345, CHU346, CHU347, CHU348, CHU350 and CHU353, suppressed damping-off of radish seedlings by the virulent isolates, CHU342, CHU349, CHU351 or CHU352 and was expressed according to a suppressiveness index. The chitinase activities of radish seedlings increased from 10 to 20 times after inoculation with suppressive isolates, CHU341, CHU344 and CHU345.
The results indicate that damping-off of radish seedlings caused by R. solani can be protected by related strains with or without plasmids. The protection of the seedlings may result from the enhancement of chitinase activities induced by the suppressive strains of R. solani. 相似文献