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111.
112.
113.
I. B. Blank A. I. Yanovskii Yu. T. Struchkov I. V. Voznyi A. A. Suvorov M. A. Kuznetsov 《Russian Chemical Bulletin》1989,38(5):981-985
1. | It has been established by x-ray structure analysis that 5,5-dimethyl-1-pyrazolinio-Z-phthalimidoimidate exists in the Z,E-configuration. The basic relationships in structure of a new class of 1,3-bipolar compounds, azimines, have been established through a comparative analysis of literature data. |
2. | The similarity in structure between this compound and the sterically unstrained Z,E-2,3-dimethyl-1-phthalimidoazimine is fully consistent with the ease of addition of phthalimidonitrene to Z-azo compounds. |
114.
Mirenskaya I. I. Litvinenko V. I. Blank A. B. Belikov V. V. 《Chemistry of Natural Compounds》1970,6(6):781-782
Chemistry of Natural Compounds - 相似文献
115.
J. Sekulic J.E. ten Elshof D.H.A. Blank 《Journal of Sol-Gel Science and Technology》2004,31(1-3):201-204
A procedure for the preparation of microporous titania membranes by the polymeric sol-gel technique is reported. The influence of acid/titanium ratio, water/titanium ratio, method of mixing components and refluxing time on particle size and sol stability was investigated. The thermal evolution, structural characteristics and liquid permeation properties of calcined materials were studied. Highly reproducible amorphous microporous titania layers with pore sizes ≤0.8 nm were obtained on both mesoporous γ-alumina and titania/zirconia coated substrates. The upper limit of thermal stability of the amorphous phase is ~300°C. Higher calcination temperatures led to phase transformation into anatase, which was accompanied by a collapse of the microstructure. The material was found to be chemically stable in a wide pH interval. 相似文献
116.
L. P. Eksperiandova K. N. Belikov S. V. Khimchenko T. A. Blank 《Journal of Analytical Chemistry》2010,65(3):223-228
The papers takes stock of different methods for evaluating the detection (c min) and determination (c lim) limits of components described in the literature and presents a comparative analysis of the results of such evaluations. It is shown that use of the data on the fluctuations of the blank experiment, in spite of their wide application for such evaluations, gives ambiguous estimates for c min and c lim. The most correct method for evaluating the specified parameters is the experimental determination of the actual analyte concentration (content) from the empirical concentration dependence of the relative standard deviation. In case when this estimation method cannot be used, it is recommended to evaluate c lim by the lower boundary of the calibration graph. The article may be useful for inexperienced analysts experimenters in choosing a method for evaluating the results obtained. 相似文献
117.
O. I. Yurchenko L. A. Yurchenko N. P. Titova T. A. Blank 《Journal of Analytical Chemistry》2004,59(8):712-714
It is shown that mercury(I) dimedonate meets the requirements imposed on the certified materials: it is homogenous and stable and the absolute value of the error of determination of mercury in a sample at P = 0.95 is 0.22%. A procedure is developed for the atomic-absorption determination of mercury in river water using the new reverence material. 相似文献
118.
As part of a collaborative study of cellular efflux of cholesterol and phospholipids, photoactivable analogues 4-8 of phosphatidylcholine (PC) having benzophenone groups in the choline moiety and at the end of the C2 and C1 alkyl chains have been synthesized. The efficient preparation via Suzuki coupling of the appropriate long-chain benzophenone-containing carboxylic acid and alcohol and their incorporation by adaptation of known approaches into the acyl- and ether-linked PC analogues 6-8 are described. Development of a method for radiolabeling these PC analogues, via hydrogenation of a double bond in modified side chains, is also described. 相似文献
119.
Gerald I. Spijksma Gulaim A. Seisenbaeva Andreas Fischer Henny J. M. Bouwmeester Dave H. A. Blank Vadim G. Kessler 《Journal of Sol-Gel Science and Technology》2009,51(1):10-22
Long-term storage at 0 °C of a paraffin-sealed flask with commercial 70 wt% solution of zirconium n-propoxide in n-propanol resulted in crystallization of an individual oxoalkoxide complex Zr4O(OnPr)14(nPrOH)2 in over 20% yield. The structure of this molecule can be described as a triangular Zr3(μ3-O)(OR)10(ROH) core of 3 edge-sharing octahedrons with an additional Zr(OR)4(ROH) unit attached through a pair of (μ-OR) bridges. Mass spectrometric and 1H NMR investigation of the commercial samples of the most broadly applied zirconium and hafnium n-propoxides and n-butoxides indicate the presence of analogous species in the commercial alkoxide precursors. The content of oxo-alkoxide species
in the commercial precursors has been estimated to be ~20% for n-propoxide and ~35% for zirconium n-butoxide. A new route has been presented for synthesis of the individual crystalline mixed ligand precursor [Zr(OnPr)(OiPr)3(iPrOH)]2, from zirconium n-propoxide. A high yield has been observed (~90%), indicative of an almost complete precursor transformation. Mass spectrometry
has shown that the synthesized mixed ligand precursor is dimeric, which makes it an attractive alternative to zirconium n-propoxide. Addition of 1 eq of Acetylacetone to zirconium or hafnium alkoxide precursors results in formation of dimeric
[M(OR)3(acac)]2 in high yields. These species have limited stability (much higher for Hf than for Zr) and transform in solution into hydrolysis-insensitive
M(acac)4 through very unstable M(acac)3(OR) intermediates containing 7-coordinated metal centers. This transformation can be followed kinetically in hydrocarbon
solvents by 1H NMR and is noticeably accelerated by addition of parent alcohols. The obtained results clearly reveal limited applicability
of EXAFS and XANES techniques for the study of such systems, especially in the context of structure prediction.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
120.
J. Giovinazzo B. Blank C. Borcea M. Chartier S. Czajkowski G. de France R. Grzywacz Z. Janas M. Lewitowicz F. de Oliveira Santos M. Pfützner M.S. Pravikoff J.C. Thomas 《The European Physical Journal A - Hadrons and Nuclei》2001,11(3):247-249
In an experiment at the SISSI/LISE3 facility of GANIL, the most proton-rich zinc isotopes 55,56Zn have been observed for the first time. The experiment was performed using a high-intensity 58Ni beam at 74.5 MeV/nucleon impinging on a nickel target. The identification of 55,56Zn opens the way to 54Zn, a good candidate for two-proton radioactivity according to theoretical predictions.
Received: 31 October 2000 / Accepted: 9 November 2000 相似文献