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131.
L. Semichon M. Flanzy A. Boidin E. Martin A. Wanscheidt O. Ieremejewa Al. Ionescu-Matiu Const Popesco H. S. King A. C. Bell C. Kollo N. Crisan G. Klein H. Linser O. Noetzel F. M. Archibald C. M. Beamer I. M. Korenman L. Palfray S. Sabetay Denise Sontag M. C. Brockmann C. H. Werkman C. Neuberg F. F. Nord C. R. Breden E. I. Fulmer L. Malaprade J. H. Birkinshaw J. H. V. Charles P. W. Clutterbuck C. B. van Niel und K. Száhlender 《Fresenius' Journal of Analytical Chemistry》1934,98(5-6):210-220
Ohne Zusammenfassung 相似文献
132.
As in the usual interstitial model, disorder is introduced by the displacement of molecules from a bonded ice-like framework onto interstitial sites. However, in this model the interstitial sites are distributed in such a way that its properties can be derived from those of an Ising model on the framework sites. Frameworks considered are the three-dimensional diamond lattice and the two-dimensional honeycomb and square lattices. Accurate liquid/vapour phase diagrams are obtained, density maxima and compressibility minima being found on the liquid branch for appropriate ratios of the non-bonding interaction energy ε to the bonding energy w. Results are compared with those of the zeroth-order and first-order approximations and isobars are calculated using the latter. For the range of ε/w giving best qualitative agreement between the three-dimensional model and experiment, the first-order and accurate results are very close in the part of the state surface where anomalous water-like properties occur. 相似文献
133.
Oils and films were produced by passage of ethylene, acetylene, and butadiene gases as well as benzene vapor through a radio-frequency electric discharge. The hydrocarbon oils produced in the plasma were dissolved in carbon tetrachloride and were analyzed by infrared and nuclear magnetic resonance spectroscopy. Based on these analyses, concentrations of characteristic functional groups were determined and used to propose molecular structures. The hydrocarbon oils are postulated to consist of irregular sequences of highly branched and incompletely crosslinked aliphatic backbone chains with pendant aromatic rings. Double bonds are interspersed along the chains. Hydrogen/carbon ratios in the proposed structures are consistent with the results from elemental analyses. Products from py-rolysis mass spectrometry can also be interpreted on the basis of the proposed structures. Similar techniques are used to analyze the structures of insoluble plasma polymerized films obtained from the same hydrocarbons. The major distinguishing feature in the films is the very high degree of crosslinking; of the order of one crosslink per six to ten chain carbon atoms. 相似文献
134.
135.
Supported by the Natural Sciences and Engineering Research Council of Canada, Grant No. A3961. 相似文献
136.
Stephen MT Hoke Gaoyang Liang A Irina Mutiu Julie Genereaux Christopher J Brandl 《BMC biochemistry》2007,8(1):16
Background
Spt7 is an integral component of the multi-subunit SAGA complex that is required for the expression of ~10% of yeast genes. Two forms of Spt7 have been identified, the second of which is truncated at its C-terminus and found in the SAGA-like (SLIK) complex. 相似文献137.
Paglialonga A Tognola G Parazzini M Lutman ME Bell SL Thuroczy G Ravazzani P 《The Journal of the Acoustical Society of America》2007,122(4):2174-2182
Mobile phones have become very commonly used worldwide within a short period of time. To date there is only limited knowledge about interaction between electromagnetic fields (EMFs) emitted by mobile phones and the auditory function. Moreover, there is widespread concern that there may be potential for harm. The aim of this study was to assess potential subtle changes in cochlear function by measuring the temporal and spectral fine structure of transiently evoked otoacoustic emissions (TEOAE) in normal hearing subjects after exposure to EMFs emitted by Global System for Mobile Communication (GSM) mobile phones. TEOAEs were recorded in 27 healthy young adults before and after 10 min of real or sham exposure in a double-blind design. TEOAE data were analyzed both globally (broadband analysis) and using the Wavelet Transform (analysis of the time-frequency fine structure). The broadband analysis revealed no significant effect on TEOAEs related to exposure, confirming results of previous studies; in addition, no significant change was detected in the analysis of the elementary wavelet components, suggesting that the temporal and spectral fine structure of TEOAEs is not affected by 10 min exposure to low-intensity EMFs emitted by GSM mobile phones. 相似文献
138.
Nicholle G. A. Bell Adam A. L. Michalchuk John W. T. Blackburn Dr. Margaret C. Graham Dr. Dušan Uhrín 《Angewandte Chemie (International ed. in English)》2015,54(29):8382-8385
Humic substances, the main component of soil organic matter, could form an integral part of green and sustainable solutions to the soil fertility problem. However, their global‐scale application is hindered from both scientific and regulatory perspectives by the lack of understanding of the molecular make‐up of these chromatographically inseparable mixtures containing thousands of molecules. Here we show how multidimensional NMR spectroscopy of isotopically tagged molecules enables structure characterization of humic compounds. We illustrate this approach by identifying major substitution patterns of phenolic aromatic moieties of a peat soil fulvic acid, an operational fraction of humic substances. Our methodology represents a paradigm shift in the use of NMR active tags in structure determination of small molecules in complex mixtures. Unlike previous tagging methodologies that focused on the signals of the tags, we utilize tags to directly probe the identity of the molecules they are attached to. 相似文献
139.
Advanced solvent signal suppression for the acquisition of 1D and 2D NMR spectra of Scotch Whisky 下载免费PDF全文
Will Kew Nicholle G.A. Bell Ian Goodall Dušan Uhrín 《Magnetic resonance in chemistry : MRC》2017,55(9):785-796
A simple and robust solvent suppression technique that enables acquisition of high‐quality 1D 1H nuclear magnetic resonance (NMR) spectra of alcoholic beverages on cryoprobe instruments was developed and applied to acquire NMR spectra of Scotch Whisky. The method uses 3 channels to suppress signals of water and ethanol, including those of 13C satellites of ethanol. It is executed in automation allowing high throughput investigations of alcoholic beverages. On the basis of the well‐established 1D nuclear Overhauser spectroscopy (NOESY) solvent suppression technique, this method suppresses the solvent at the beginning of the pulse sequence, producing pure phase signals minimally affected by the relaxation. The developed solvent suppression procedure was integrated into several homocorrelated and heterocorrelated 2D NMR experiments, including 2D correlation spectroscopy (COSY), 2D total correlation spectroscopy (TOCSY), 2D band‐selective TOCSY, 2D J‐resolved spectroscopy, 2D 1H, 13C heteronuclear single‐quantum correlation spectroscopy (HSQC), 2D 1H, 13C HSQC‐TOCSY, and 2D 1H, 13C heteronuclear multiple‐bond correlation spectroscopy (HMBC). A 1D chemical‐shift‐selective TOCSY experiments was also modified. The wealth of information obtained by these experiments will assist in NMR structure elucidation of Scotch Whisky congeners and generally the composition of alcoholic beverages at the molecular level. 相似文献
140.
Surman AJ Bonnet CS Lowe MP Kenny GD Bell JD Tóth E Vilar R 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(1):223-230
This study shows that the relaxivity and optical properties of functionalised lanthanide‐DTPA‐bis‐amide complexes (lanthanide=Gd3+ and Eu3+, DTPA=diethylene triamine pentaacetic acid) can be successfully modulated by addition of specific anions, without direct Ln3+/anion coordination. Zinc(II)‐dipicolylamine moieties, which are known to bind strongly to phosphates, were introduced in the amide “arms” of these ligands, and the interaction of the resulting Gd–Zn2 complexes with a range of anions was screened by using indicator displacement assays (IDAs). Considerable selectivity for polyphosphorylated species (such as pyrophosphate and adenosine‐5′‐triphosphate (ATP)) over a range of other anions (including monophosphorylated anions) was apparent. In addition, we show that pyrophosphate modulates the relaxivity of the gadolinium(III) complex, this modulation being sufficiently large to be observed in imaging experiments. To establish the binding mode of the pyrophosphate and gain insight into the origin of the relaxometric modulation, a series of studies including UV/Vis and emission spectroscopy, luminescence lifetime measurements in H2O and D2O, 17O and 31P NMR spectroscopy and nuclear magnetic resonance dispersion (NMRD) studies were carried out. 相似文献