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51.
The purple sulphur bacterium Thiocapsa roseopersicina, strain BBS, grown in the darkness in aerobic autotrophic conditions, oxidized sulphides to free sulphur and then to sulphates. This was accompanied with the fixation of carbon dioxide by the cells. Addition of glucose to the mineral medium increased the biomass yield; the cells oxidized thiosulphate still at a high rate. These results prove the possibility of switching T. roseopersicina from photosynthesis to a dark chemolithautotrophic way of life. 相似文献
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Presence of plasmid DNA was investigated in laboratory strains 2 and 4 (NRRL 2338) of S. erythreus, as well as in strains 1 and 3 of S. erythreus subjected to improvement with respect to erythromycin production. Families of plasmids close by their molecular weights were identified in S. erythreus strains 3 and 4 (NRRL 2338). A plasmid DNA fraction of S. erythreus strain 3 was studied with electron microscopy. It enabled to identify 5 plasmids: pSE11, pSE12, pSE13, pSE14 and pSE15 with length of 5.3, 12.4, 16.3, 29.6 and 86.9 kb respectively. Using of various procedures for isolation of extrachromosomal DNA did not provide its detection in S. erythreus strains 1 and 2. At least a part of the plasmids detected in S. erythreus strains 3 and 4 (NRRL 2338) was conjugative. 32R-Labeled plasmid DNA of S. erythreus strain 3 was subjected to hydridization according to Sauthern with total DNA of the 4 strains treated with restrictases BamHI, PstI and BgIII. The studies showed that the genome of S. erythreus strain 2 was not homologous with the probe while S. erythreus strain 1 contained one of the plasmids or its part in chromosome-integrated state. In strains 3 and 4 (NRRL 2338) of S. erythreus certain plasmid DNAs were present in both autonomous and chromosome-inserted states. 32P-Labeled gene of erythromycin resistance (ermE) was subjected to hybridization according to Southern with total DNA of the 4 strains and with DNA plasmid fraction of S. erythreus strain 3. The signal was positive only in hydridization of the probe with total DNA of S. erythreus strains 1, 3, and 4 (NRRL 2338).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
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Igor Lipušček Marko Bohanec Leon Oblak Lidija Zadnik Stirn 《The International Journal of Life Cycle Assessment》2010,15(4):359-367
Background, aim and scope
Although life cycle assessment is frequently used in scientific studies of product comparison, many practitioners are looking for improvements in the normalisation, grouping and weighting of life cycle inventory results. Local conditions, which are well known to local experts, are very important to these steps. The goal of this work was to develop a computer-based decision support system for classifying wood products according to their influence on the environment in their whole life cycle. The model specifically addresses local conditions in the Republic of Slovenia and was developed by Slovenian experts. 相似文献56.
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Ming Xu Vladimir V. Ermolenkov Vladimir N. Uversky Igor K. Lednev 《Journal of biophotonics》2008,1(3):215-229
Amyloid fibrils are associated with numerous degenerative diseases. The molecular mechanism of the structural transformation of native protein to the highly ordered cross‐β structure, the key feature of amyloid fibrils, is under active investigation. Conventional biophysical methods have limited application in addressing the problem because of the heterogeneous nature of the system. In this study, we demonstrated that deep‐UV resonance Raman (DUVRR) spectroscopy in combination with circular dichroism (CD) and intrinsic tryptophan fluorescence allowed for quantitative characterization of protein structural evolution at all stages of hen egg white lysozyme fibrillation in vitro. DUVRR spectroscopy was found to be complimentary to the far‐UV CD because it is (i) more sensitive to β ‐sheet than to α ‐helix, and (ii) capable of characterizing quantitatively inhomogeneous and highly light‐scattering samples. In addition, phenylalanine, a natural DUVRR spectroscopic biomarker of protein structural rearrangements, exhibited substantial changes in the Raman cross section of the 1000‐cm–1 band at various stages of fibrillation. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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Karuppanan Muthusamy Kathir Li Gao Dakshinamurthy Rajalingam Sherri Brixey Dan Davis Igor Prudovsky 《生物化学与生物物理学报:生物膜》2010,1798(2):297-302
Human fibroblast growth factor (hFGF-1) is a ∼ 17 kDa heparin binding cytokine. It lacks the conventional hydrophobic N-terminal signal sequence and is secreted through non-classical secretion routes. Under stress, hFGF-1 is released as a multiprotein complex consisting of hFGF-1, S100A13 (a calcium binding protein), and p40 synaptotagmin (Syt1). Copper (Cu2+) is shown to be required for the formation of the multiprotein hFGF-1 release complex (Landriscina et al. ,2001; Di Serio et al., 2008). Syt1, containing the lipid binding C2B domain, is believed to play an important role in the eventual export of the hFGF-1 across the lipid bilayer. In this study, we characterize Cu2+ and lipid interactions of the C2B domain of Syt1 using multidimensional NMR spectroscopy. The results highlight how Cu2+ appears to stabilize the protein bound to pS vesicles. Cu2+ and lipid binding interface mapped using 2D 1H-15N heteronuclear single quantum coherence experiments reveal that residues in β-strand I contributes to the unique Cu2+ binding site in the C2B domain. In the absence of metal ions, residues located in Loop II and β-strand IV contribute to binding to unilamelar pS vesicles. In the presence of Cu2+, additional residues located in Loops I and III appear to stabilize the protein-lipid interactions. The results of this study provide valuable information towards understanding the molecular mechanism of the Cu2+-induced non-classical secretion of hFGF-1. 相似文献