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61.
Tatakuntla Satyanarayana Nageswara Rao Anipindi Veeraputhiran Subbiah Madhusudan Waman Pandit 《Transition Metal Chemistry》1993,18(1):93-95
Summary The reaction between bis(2,4,6-tripyridyl-1,3,5-triazine)-iron(II), Fe(TPTZ)
inf2
sup2+
and chromium(VI) in acetate buffers is very slow. However, in the presence of oxalic acid (catalyst) it is very fast and is completed within 10s. The reaction was studied in the 3.6–5.6 pH range using stopped-flow spectrophotometry. The reaction is first order in the substrate and zero order in the oxidant. The rate of the reaction increases with the increase in pH. Kinetic evidence for complexation between the substrate and the catalyst was obtained and a mechanism involving the formation of an ion-pair between Fe(TPTZ)
inf2
sup2+
and the oxalate ion is proposed. 相似文献
62.
Madhusudan Bhandapy 《Annals of the Institute of Statistical Mathematics》1991,43(4):689-705
An iterative algorithm for the robust M-estimation of the dispersion matrix of the form + 2
I
p
has been given. This algorithm converges after some steps and reduces the effect of outliers on the covariance matrix. The consistency and asymptotic normality of the estimator are established. 相似文献
63.
Ravi Kumar Dr. Madhusudan K. Pandey Dr. Indresh K. Pandey Dr. Abhishek Kumar Prof. Dr. Joyanta Choudhury 《欧洲无机化学杂志》2023,26(29):e202300411
Herein we report the first mesoionic carbene (MIC)-Mn(I) complex Mn-bim-MICimz derived from imidazolylidene motif. Structurally the octahedral Mn(I) complex Mn-bim-MICimz was assembled with an anionic benzimidazolato-anchored imidazolylidene MIC-based bidentate ligand ( bim-MICimz ) and four CO ligands, as supported by detailed characterization using NMR and FTIR spectroscopy, mass spectrometry, and single crystal X-ray diffraction study. We reckoned that the bim-MICimz ligand would provide a robust and stable bonding with the Mn(I) centre, and also enhance electron density at the Mn(I) centre through its stronger σ-donating/weaker π-accepting property. These structural and electronic attributes triggered to exploit Mn-bim-MICimz in catalytic hydrogenation of N-heteroarenes, where efficient hydride (Mn−H) delivery is a key step. 相似文献
64.
Kundu S Maheshwari V Saraf RF 《Langmuir : the ACS journal of surfaces and colloids》2008,24(2):551-555
An electroless, photolytic method is described to synthesize Au nanoclusters and electrically conductive, micronmeter long nanostructures on DNA. Electrical characterization indicates that the Au nanostructures are continuous, exhibiting Ohmic behavior with very low contact resistance with the electrodes. The nanoclusters have a size of 10-40 nm, and the nanostructure have a diameter of 40-70 nm with resistivity comparable to that of pure metal. The method is highly selective with deposition confined to the DNA template. 相似文献
65.
We present measurements of the power noise due to optical amplification in a Nd:YAG free-space traveling-wave amplifier as the amplifier transitions from the linear regime into the heavily saturated regime. The quantum noise behavior is demonstrated by saturating the gain of a 100-W class zigzag slab amplifier with a high-power beam and measuring the power noise detected by a single-spatial-mode probe beam traversing the same optical path through the amplifier. 相似文献
66.
W H Madhusudan Sheelavathi Kollali P R Sarode M S Hegde P Ganguly C N R Rao 《Pramana》1979,12(4):317-329
X-ray and ultraviolet photoelectron spectroscopy as well as x-ray absorption spectroscopy have been employed to investigate
transition metal oxide perovskites of the general formula ABO3 (A = La or rare-earth ion, B=trivalent transition metal ion). Systematics in the core levels and in the valence bands in
the series of LaBO3 compounds have been discussed. Lanthanum chemical shifts in the x-ray absorption spectra in this series show interesting
trends. Photoelectron spectra of the solid solutions, LaNi1−x
Co
x
O3, LaNi1−x
Fe
x
O3 and LaFe1−x
Co
x
O3 show that the rigid band model is applicable to these systems. It is shown that x-ray photoelectron spectroscopy can be employed
to identify multiple oxidation states of transition metal ions in oxide perovskites.
Communication No. 30 from the Solid State and Structural Chemistry Unit.
An erratum to this article is available at . 相似文献
67.
L. V. Saraf P. Nachimuthu M. H. Engelhard D. R. Baer 《Journal of Sol-Gel Science and Technology》2010,53(2):141-147
The stabilization and analysis of pure ZnMnO3 phase may help to understand the solubility limits of Mn in ZnO in wurtzite and cubic structures. In this report, synthesis
and characterization of stable ZnMnO3 phase is discussed which is extracted from sol–gel synthesis of zinc and manganese nitrate precursors. The reflections at
higher diffraction angles for this known cubic system with space group Fd3 m were calculated with the help of JADE 8.0 program.
The reliability factor for ZnMnO3 calculated from Rietveld refinement was 2%. A narrow phase pure ZnMnO3 stabilization region was identified with the help of energy dispersive spectroscopy mapping. High resolution X-ray photoelectron
spectroscopy measurements of Mn3p position of ZnMnO3 compared with ZnMn2O4 showed a higher binding energy shift ~0.85 eV indicating Mn4+ valence state in ZnMnO3. 相似文献
68.
Tian J Saraf LV Schwenzer B Taylor SM Brechin EK Liu J Dalgarno SJ Thallapally PK 《Journal of the American Chemical Society》2012,134(23):9581-9584
Flexible anionic metal-organic frameworks (MOFs) are transformed into neutral heterobimetallic systems via single-crystal-to-single-crystal processes invoked by cation insertion. These transformations are directed by cooperative bond breakage and formation, resulting in expansion or contraction of the 3D framework by up to 33% due to the flexible nature of the organic linker. These MOFs displays highly selective uptake of divalent transition-metal cations (e.g., Co(2+) and Ni(2+)) over alkali-metal cations (Li(+) and Na(+)). 相似文献
69.
70.
Gold and silver in dross were determined by energy‐dispersive X‐ray fluorescence technique. Sample was prepared by pressed pellet method using microcrystalline cellulose powder as binder, and a method of standard additions was used for quantification. Lβ X‐ray of gold (11.4 keV) and Kβ X‐ray of silver (24.9 keV) were used for analysis. The measured concentrations of gold and silver were 132 ± 8 and 1181 ± 84 mg kg?1, respectively. The results were validated by instrumental neutron activation analysis technique. The t‐test indicated that there was no significant difference between results obtained by the two techniques. Energy‐dispersive X‐ray fluorescence is a simple, precise and accurate technique for the determination of gold and silver in dross. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献