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121.
Composting of explosives and propellant contaminated soils under thermophilic and mesophilic conditions 总被引:3,自引:0,他引:3
Richard T. Williams P. Scott Ziegenfuss Wayne E. Sisk 《Journal of industrial microbiology & biotechnology》1992,9(2):137-144
Summary Composting was investigated as a bioremediation technology for clean-up of sediments contaminated with explosives and propellants. Two field demonstrations were conducted, the first using 2,4,6-trinitrotoluene (TNT), octahydro-1,3,5,7-tetranitro-1,3,5,7-tetraazocine (HMX), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), and N-methyl-N,2,4,6-tetranitroaniline (tetryl) contaminated sediment, and the second using nitrocellulose (NC) contaminated soil. Tests were conducted in thermophilic and mesophilic aerated static piles. Extractable TNT was reduced from 11840 mg/kg to 3 mg/kg, and NC from 13090 mg/kg to 16 mg/kg under thermophilic conditions. Under mesophilic conditions, TNT was reduced from 11 190 mg/kg to 50 mg/kg. The thermophilic and mesophilic half-lives were 11.9 and 21.9 days for TNT, 17.3 and 30.1 days for RDX, and 22.8 and 42.0 days for HMX, respectively. Known nitroaromatic transformation products increased in concentration over the first several weeks of the test period, but decreased to low concentrations thereafter. 相似文献
122.
Matthew R. Wright Saeed Sattari Dion R. Brocks Fakhreddin Jamali 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1992,583(2)
A rapid, inexpensive and sensitive high-performance liquid chromatographic method for the quantitation of ibuprofen enantiomers from a variety of biological fluids is reported. This method uses a commercially available internal standard and has significantly less interference from endogenous co-extracted solutes than do previously reported methods. The method involves the acid extraction of drug and internal standard [(±)-fenoprofen] from the biological fluid with isooctane—isopropanol (95:5) followed by evaporation and derivatization with enthylchloroformate and R-(+)-α-phenylethylamine. Excellent linearity was observed between the peak-area ratio and enantiomer concentration (r > 0.99) over a concentration range of 0.25–50 μg/ml. This method is suitable for the quantitation of ibuprofen from single-dose pharmacokinetic studies involving either rats or humans. 相似文献
123.
T M Reilly R Seetharam J L Duke G L Davis S K Pierce H L Walton D Kingsley W P Sisk 《The Journal of biological chemistry》1990,265(16):9570-9574
A recombinant form of plasminogen activator inhibitor-1 (rPAI-1) has been purified from lysates of pCE1200, a bacterial expression vector containing the full length PAI-1 gene, by utilizing sequential anion exchange and cation exchange chromatography on Q-Sepharose and S-Sepharose columns. Approximately 140 mg of rPAI-1, estimated at 98% purity on the basis of analytical high performance liquid chromatography, could be obtained from 200 g wet weight of cells. The purified protein exhibited a single Coomassie Blue-stainable band at the region of Mr = 42,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and an NH2-terminal amino acid sequence consistent with the expected translation product of the pCE1200 PAI-1 insert. The rPAI-1 rapidly inhibited single- and two-chain tissue plasminogen activators, as well as urokinase, with apparent second order rate constants in the range of 2-5 x 10(7) M-1 s-1. A specific activity measurement of 250,000 units/mg was calculated for the rPAI-1 based on its ability to inhibit the enzymatic activity of a single-chain tissue plasminogen activator. Stability studies showed that the activity of the rPAI-1 was very stable when stored at temperatures of 25 degrees C or lower, but decayed within hours when stored at 37 degrees C. Sodium dodecyl sulfate treatment, which partially activates the latent form of natural PAI-1, inactivated rPAI-1. These results show that the purified rPAI-1 produced from pCE1200 displays many of the properties associated with the biologically active form of natural PAI-1. 相似文献
124.
Paul A. Andrews Merrill J. Egorin Matthew E. May Nicholas R. Bachur 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1982,227(1):83-91
6-Thioguanine (6TG) and its metabolites were analyzed in human plasma with a reversed-phase high-performance liquid chromatographic method. 6TG and related compounds were extracted from plasma with an equal volume of 2 N perchloric acid at a 50–100% recovery efficiency. The neutralized extracts were chromatographed on a μBondapak C18 column by two separate isocratic conditions. 6TG, 6-thiouric acid, 6-thioxanthine, 6-thioguanosine, and 6-methylthiouric acid were analyzed with 0.01 M sodium acetate, pH 3.5–10% methanol as the mobile phase and 340 nm for detection. 6-Methylthioguanine and three unknown metabolites were separated with acetate—25% methanol and 310 nm detection. One of the unknowns was identified as 6-methylthioguanosine. External standard calibration was used for quantitation. The 6TG detection limit was 0.8 nmol/ml in plasma. 相似文献
125.
The modified Tanford-Kirkwood theory of Shire et al. [Shire, S. J., Hanania, G.I.H., & Gurd, F.R.N. (1974) Biochemistry 13, 2967] for electrostatic interactions was applied to the hydrogen ion equilibria of human deoxyhemoglobin and oxyhemoglobin. Atomic coordinates for oxyhemoglobin were generated by the application of the appropriate rigid rotation function to alpha and beta chains of the deoxyhemoglobin structure [Fermi, G. (1975) J. Mol. Biol. 97, 237]. The model employs two sets of parameters derived from the crystalline protein structures, the atomic coordinates of charged amino acid residues and static solvent accessibility factors to reflect their individual degrees of exposure to solvent. Theoretical titration curves based on a consistent set of pKint values compared closely with experimental potentiometric curves. Theoretical pK values at half-titration for individual protein sites corresponded to available observed values for both quaternary states. The results bring out the cumulative effects of numerous electrostatic interactions in the tetrameric structures and the major effects of the quaternary transition that result from changes in static solvent accessibility of certain ionizable groups. 相似文献
126.
Types of beta-lactamase determined by plasmids in gram-negative bacteria. 总被引:22,自引:0,他引:22 下载免费PDF全文
Two species of beta-lactamase determined by plasmids in enteric bacteria that show some resemblance to TEM enzymes are described. Both are distinct from all other plasmid-mediated beta-lactamases and differ from the TEM beta-lactamases in ability to hydrolyze some substrates, in isoelectric point, in immunological specificity, and in susceptibility to inhibition. One of the enzyme species, mediated by plasmid p453, has been briefly described previously. We have discovered that this beta-lactamase, designated SHV-1, is unique in its response to inhibition by the sulfhydryl group reagent p-chloromercuribenzoate, because the hydrolysis of cephaloridine but not that of benzylpenicillin is affected. This enzyme is found in a variety of plasmid types which were transferred from several bacterial species collected from a wide geographic range. The other enzyme species is novel; only a single plasmid determining this kind of beta-lactamase (designated HMS-1) has been detected. 相似文献
127.
J B Matthew S H Friend L H Botelho L D Lehman G I Hanania F R Gurd 《Biochemical and biophysical research communications》1978,81(2):416-421
The modified Tanford-Kirkwood theory of Shire et al. for intramolecular electrostatic interactions has been applied to hydrogen ion equilibria of sperm whale ferrimyoglobin, human hemoglobin α-chain and horse cytochrome c. The model employs two sets of parameters derived from the crystalline protein structures, first, the atomic coordinates of charged amino acid residues and, second, static accessibility factors to reflect their solvent exposure. In addition, a consistent set of intrinsic pK values (pKint) for the individual groups is employed. The theoretical pK values at half-titration for individual groups in each protein correspond to the available observed pK values, and the theoretical titration curves compare closely with experimental potentiometric curves. 相似文献
128.
Terence Galliard Jennifer A. Matthew Michael J. Fishwick Anthony J. Wright 《Phytochemistry》1976,15(11):1647-1650
Homogenization of fresh tissue from cucumber fruits results in a loss of endogenous lipid catalysed by acyl hydrolase enzymes. Deacylation of lipids is not accompanied by accumulation of free fatty acids. The levels of both saturated (mainly palmitic) and polyunsaturated (linoleic and linolenic) fatty acids in the lipids are reduced. Losses of the major acyl lipid constituents of cucumber (triacylglycerols and phospholipids) are mainly responsible for the observed hydrolysis. Triacylglycerol acyl hydrolase (lipase), phospholipase D and polar lipid acyl hydrolase enzyme activities were demonstrated. It is suggested that hydrolytic attack on endogenous lipids is the initial event on disruption of cucumber tissue, in the formation of lipid degradation products, amongst which are the volatile carbonyl compounds responsible for the characteristic flavour of cucumber. 相似文献
129.
Plasmid-determined beta-lactamase indistinguishable from the chromosomal beta-lactamase of Escherichia coli. 总被引:2,自引:2,他引:0 下载免费PDF全文
M M Bobrowski M Matthew P T Barth N Datta N J Grinter A E Jacob P Kontomichalou J W Dale J T Smith 《Journal of bacteriology》1976,125(1):149-157
A plasmid, derived from a naturally occurring strain of Proteus mirabilis, conferred resistance to cephalosporins, apparently mediated by a beta-lactamase indistinguishable from that determined by the chromosomal gene of Escherichia coli K-12. There was evidence for a recombination event between the wild-type plasmid and a defective F factor (Fsp) in the Escherichia coli K-12 culture in which it was stored. 相似文献
130.