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51.
Graham E. O'Mahony Kevin S. Eccles Robin E. Morrison Alan Ford Simon E. Lawrence Anita R. Maguire 《Tetrahedron》2013
Steric and electronic effects in the copper-catalysed asymmetric oxidation of aryl benzyl, aryl alkyl and alkyl benzyl sulfides have been investigated. The presence of an aryl group directly attached to the sulfur is essential to afford sulfoxides with high enantioselectivities, with up to 97% ee for 2-naphthyl benzyl sulfoxide, the highest enantioselectivity achieved to date for copper-catalysed asymmetric sulfoxidation. In contrast, the benzyl substituent can be replaced by sterically comparable groups with no effect on enantioselectivity. Copper-mediated oxidation of substituted aryl benzyl sulfides display modest steric and electronic effects resulting in comparable or lower enantioselectivities to those obtained with the unsubstituted benzyl phenyl sulfide. 相似文献
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53.
Synthesis and Biological Evaluation of a Class of Mitochondrially‐Targeted Gadolinium(III) Agents
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Dr. Daniel E. Morrison Dr. Jade B. Aitken Dr. Martin D. de Jonge Dr. Fatiah Issa Prof. Hugh H. Harris Prof. Louis M. Rendina 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(50):16602-16612
A structure–activity relationship study of a library of novel bifunctional GdIII complexes covalently linked to arylphosphonium cations is reported. Such complexes have been designed for potential application in binary cancer therapies such as neutron capture therapy and photon activation therapy. A positive correlation was found between lipophilicity and cytotoxicity of the complexes. Mitochondria uptake was determined by means of inductively coupled plasma mass spectrometry (ICP‐MS), and Gd uptake was determined by means of quantification using synchrotron X‐ray fluorescence (XRF) imaging. A negative correlation between lipophilicity and tumour selectivity of the GdIII complexes was demonstrated. This study highlights the delicate balance required to minimise in vitro cytotoxicity and optimise in vitro tumour selectivity and mitochondrial localisation for this new class of mitochondrially‐targeted binary therapy agents. We also report the highest in vitro tumour selectivity for any Gd agent reported to date, with a T/N (tumour/normal cell) ratio of up to 23.5±6.6. 相似文献
54.
Douglas J. Morrison Karen Cooper Tom Preston 《Rapid communications in mass spectrometry : RCM》2010,24(12):1799-1804
Carbon isotope analysis by bulk elemental analysis coupled with isotope ratio mass spectrometry has been the mainstay of δ13C analyses both at natural abundance and in tracer studies. More recently, compound‐specific isotope analysis (CSIA) has become established, whereby organic constituents are separated online by gas or liquid chromatography before oxidation and analysis of CO2 for constituent δ13C. Theoretically, there should be concordance between bulk δ13C measurements and carbon‐weighted δ13C measurements of carbon‐containing constituents. To test the concordance between the bulk and CSIA, fish oil was chosen because the majority of carbon in fish oil is in the triacylglycerol form and ~95% of this carbon is amenable to CSIA in the form of fatty acids. Bulk isotope analysis was carried out on aliquots of oil extracted from 55 fish samples and δ13C values were obtained. Free fatty acids (FFAs) were produced from the oil samples by saponification and derivatised to fatty acid methyl esters (FAMEs) for CSIA by gas chromatography/combustion/isotope ratio mass spectrometry. A known amount of an internal standard (C15:0 FAME) was added to allow analyte quantitation. This internal standard was also isotopically calibrated in both its FFA (δ13C = ?34.30‰) and FAME (δ13C = ?34.94‰) form. This allowed reporting of FFA δ13C from measured FAME δ13C values. The bulk δ13C was reconstructed from CSIA data based on each FFA δ13C and the relative amount of CO2 produced by each analyte. The measured bulk mean δ13C (SD) was ?23.75‰ (1.57‰) compared with the reconstructed bulk mean δ13C of ?23.76 (1.44‰) from CSIA and was not significantly different. Further analysis of the data by the Bland‐Altman method did not show particular bias in the data relative to the magnitude of the measurement. Good agreement between the methods was observed with the mean difference between methods (range) of 0.01‰ (?1.50 to 1.30). Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
55.
[formula: see text] The synthesis of 1,3-difluoro-2,4-diphenylbenzene has been accomplished in one step from 1,2-diphenylcyclobutene using the environmentally benign difluorocarbene precursor sodium chlorodifluoroacetate. In addition, the preparation of the previously unknown compound 1,3-difluoro-2,4-di-n-propylbenzene has been accomplished in one step from 1,2-di-n-propylcyclobutene using Seyferth's reagent (Ph-Hg-CF3) and sodium chlorodifluoroacetate. 相似文献
56.
Bornheim A Lipeles E Pappas SP Shapiro A Sun WM Weinstein AJ Masek G Paar HP Mahapatra R Morrison RJ Briere RA Chen GP Ferguson T Tatishvili G Vogel H Adam NE Alexander JP Bebek C Berkelman K Blanc F Boisvert V Cassel DG Drell PS Duboscq JE Ecklund KM Ehrlich R Gibbons L Gittelman B Gray SW Hartill DL Heltsley BK Hsu L Jones CD Kandaswamy J Kreinick DL Magerkurth A Mahlke-Krüger H Meyer TO Mistry NB Nordberg E Palmer M Patterson JR Peterson D Pivarski J Riley D Sadoff AJ Schwarthoff H 《Physical review letters》2002,88(23):231803
We report a new measurement of the Cabibbo-Kobayashi-Maskawa parameter Vub made with a sample of 9.7 x 10(6) BB- events collected with the CLEO II detector. Using heavy quark theory, we combine the observed yield of leptons from semileptonic B decay in the end-point momentum interval 2.2-2.6 GeV/c with recent CLEO II data on B-->X(s)gamma to find Vub = (4.08+/-0.34+/-0.44+/-0.16+/-0.24)x10(-3), where the first two uncertainties are experimental and the last two are from theory. 相似文献
57.
Edwards CA Zavoshy R Khanna S Slater C Morrison DJ Preston T Weaver LT 《Isotopes in environmental and health studies》2002,38(3):139-147
Stable isotope breath tests offer a new approach to the study of digestion and fermentation of carbohydrates in man. In this study, 13C labelled peas were grown by pulsing 250 ml 13CO2 into a sealed growth chamber. A second pulse was added to a portion of the peas to increase the 13C enrichment. This generated pea flour with an enrichment of 2.36 at.% excess (range 2.09-2.71 n = 3) and 8.64 atom % excess (range 7.37-9.78 n = 3) respectively. This represented incorporation of an absolute yield of 3.8% of the 13CO2 into peas in the 'once-labelled' treatment and 7.5% in the 'twice-labelled' treatment. Ingestion of a mixture of the labelled pea flour (300 mg) by two volunteers generated measurable 13CO2 excretion for breath test analysis. The profile of breath 13CO2 enrichment increased to a maximum within three hours after consuming the pea flour followed by a decrease almost back to baseline by 13 hours. Breath 13CO2 appeared to rise again after this apparent nadir at 13 hours until the end of the sampling period. Mathematical analysis of the data suggested that two peaks best described the profile of breath 13CO2 up to 13 hours. A third peak was necessary to describe the late rise in breath 13CO2 enrichment. This use of 13C enriched pea flour may provide a useful non invasive method for measurement of digestion and fermentation in vivo. 相似文献
58.
The oxidative in vitro metabolism of epibatidine was investigated using liver microsomes from rat, dog, rhesus monkey and human. Analysis was performed using liquid chromatography-mass spectrometry (LC-MS) using both achiral and chiral stationary phases. Comparison of the metabolism of the (+)- and (-)-enantiomers revealed species differences in the extent of metabolism, with rhesus monkey>dog>rat=human. Furthermore, differences in the routes of metabolism for epibatidine enantiomers were also observed, with mass spectra consistent with hydroxylation of the azabicycle for (-)-epibatidine and with the formation of diastereomeric N-oxides for (+)-epibatidine being obtained. For chiral LC-MS, a volatile ion-pair reagent of heptafluorobutyric acid was used in place of pentanesulphonic acid with no deterioration in chiral selectivity. Analysis of the same samples by chiral LC-MS revealed no evidence for metabolic chiral interconversion and chiral analysis from a metabolic time course of racemic material revealed enantiomers to be metabolised to approximately the same extent. Such findings may be important particularly should epibatidine be investigated in non-rodent species. 相似文献
59.
60.
S. F. Peterson F. Tera G. H. Morrison 《Journal of Radioanalytical and Nuclear Chemistry》1969,2(1-2):115-125
Isotopic ion exchange for the rapid separation of radioactive mixtures has been further extended through the use of an acetone-water-hydrochloric
acid system. Distribution data were obtained for 27 elements in the range of 15–90% acetone, 0.3N HCl indicating a number of new separations. The approach was used for the separation of several radioisotopes from short
half-life magnesium matrix for activation analysis. The separations were completed in less than 5 minutes.
Research supported by the Advanced Research Projects Agency. 相似文献