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排序方式: 共有129条查询结果,搜索用时 140 毫秒
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A. P. Gulea S. N. Spynu V. I. Tsapkov D. Poirier J. Roy 《Russian Journal of General Chemistry》2006,76(9):1458-1463
Isatin (L1) and N-methylisatin (L2) β-thiosemicarbazones react in ethanol with Cu(II) chloride and bromide in the presence of sulfanilamide (Streptocid, Sf1), N-acetylsulfanilamide (Sulfacyl, Sf2), Norsulfazole (Sf3), Aethazolum (Sf4), and Sulfadimesine (Sf5) to form coordination compounds Cu(Sf1–5)L1–2X2 · nH2O (X = Cl, Br; n = 2–5). All the complexes have a monomeric structure. Thiosemicarbazones L1 and L2 in these complexes are tridentate O,N,S ligands, and sulfanilamides Sf1–5 are monodentate ligands. Thermolysis of the substances involves the steps of dehydration (70–95°C) and complete decomposition (410–530°C). 相似文献
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Petrenko P. A. Gdaniec M. Simonov Yu. A. Stavila V. G. Gulea A. P. 《Russian Journal of Coordination Chemistry》2004,30(11):813-817
A Ni(II) complex of the composition Ni(HNta) · 4H2O (I) was synthesized. Its structure was found to consist of neutral mononuclear [Ni(HNta)(H2O)3] complexes and crystallization water molecules. The Ni atom has octahedral surrounding and is coordinated to tridentate-chelate HNta2– ligand through the N atom and O atoms of two deprotonated acetate groups and through the O atoms of three water molecules. The structure of I was compared with those of the Zn(HNta) · 4H2O and Co(HNta) · 4H2O complexes isostructural to I. Thermogravimetric method showed that the decomposition of compound I occurs through several successive stages of dehydration, deaquation, decarboxylation, and the formation of inorganic residue. 相似文献
4.
Aurelian Gheondea 《Integral Equations and Operator Theory》2012,74(4):451-479
We investigate VH-spaces (Vector Hilbert spaces, or Loynes spaces) operator valued Hermitian kernels that are invariant under actions of *-semigroups from the point of view of generation of *-representations, linearizations (Kolmogorov decompositions), and reproducing kernel spaces. We obtain a general dilation theorem in both Kolmogorov and reproducing kernel space representations, that unifies many dilation results, in particular B. Sz.-Nagy??s and Stinesprings?? dilation type theorems. 相似文献
5.
Efficient computation of operator‐type response sensitivities for uncertainty quantification and predictive modeling: illustrative application to a spent nuclear fuel dissolver model 下载免费PDF全文
This work honors the 75th birthday of Professor Ionel Michael Navon by presenting original results highlighting the computational efficiency of the adjoint sensitivity analysis methodology for function‐valued operator responses by means of an illustrative paradigm dissolver model. The dissolver model analyzed in this work has been selected because of its applicability to material separations and its potential role in diversion activities associated with proliferation and international safeguards. This dissolver model comprises eight active compartments in which the 16 time‐dependent nonlinear differential equations modeling the physical and chemical processes comprise 619 scalar and time‐dependent model parameters, related to the model's equation of state and inflow conditions. The most important response for the dissolver model is the time‐dependent nitric acid in the compartment furthest away from the inlet, where measurements are available at 307 time instances over the transient's duration of 10.5 h. The sensitivities to all model parameters of the acid concentrations at each of these instances in time are computed efficiently by applying the adjoint sensitivity analysis methodology for operator‐valued responses. The uncertainties in the model parameters are propagated using the above‐mentioned sensitivities to compute the uncertainties in the computed responses. A predictive modeling formalism is subsequently used to combine the computational results with the experimental information measured in the compartment furthest from the inlet and then predict optimal values and uncertainties throughout the dissolver. This predictive modeling methodology uses the maximum entropy principle to construct an optimal approximation of the unknown a priori distribution for the a priori known mean values and uncertainties characterizing the model parameters and the computed and experimentally measured model responses. This approximate a priori distribution is subsequently combined using Bayes' theorem with the “likelihood” provided by the multi‐physics computational models. Finally, the posterior distribution is evaluated using the saddle‐point method to obtain analytical expressions for the optimally predicted values for the parameters and responses of both multi‐physics models, along with corresponding reduced uncertainties. This work shows that even though the experimental data pertains solely to the compartment furthest from the inlet (where the data were measured), the predictive modeling procedure used herein actually improves the predictions and reduces the predicted uncertainties for the entire dissolver, including the compartment furthest from the measurements, because this predictive modeling methodology combines and transmits information simultaneously over the entire phase‐space, comprising all time steps and spatial locations. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
6.
Mihaela Gulea Isabelle Abrunhosa Jozef Drabowicz Guillaume Grach Matthieu Hamel Serge Masson 《Phosphorus, sulfur, and silicon and the related elements》2013,188(5-6):1267-1272
Abstract A new method to prepare enantioenriched sulfinates was developed to obtain optically active ortho-methylsulfinyl(phenylphosphonates). It consists of a diastereoselective oxidation of sulfenates to sulfinates. Additionally, preliminary results concerning the synthesis of ortho-phophonylated benzylic thiol derivatives via a new P═S to P═C [1,4]-rearrangement and a first synthetic application of these compounds are also described. 相似文献
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Aurelian Cernea 《Journal of Applied Mathematics and Computing》2012,38(1-2):133-143
The existence of solutions of an anti-periodic boundary value problem for fractional differential inclusions of order ????(2,3] is investigated. Several results are obtained by using suitable fixed point theorems when the right hand side has convex or non convex values. 相似文献
9.
Flavie Peudru Remi Legay Jean-François Lohier Vincent Reboul Mihaela Gulea 《Tetrahedron》2012,68(44):9016-9022
A new efficient and general synthetic methodology to access γ-aminothiols was investigated and developed. 1,3-Thiazines were used as convenient precursors and were prepared by a fast microwave-assisted three-component reaction (3CR) of thioamides, aldehydes, and alkenes. The transformation of thiazines into aminothiols was achieved via a thiazinium salt hydrolysis, in three very facile steps. 相似文献
10.
Morarescu O. Grinco M. Kulcitki V. Barba A. Garbuz O. Gulea A. Ungur N. 《Russian Journal of Organic Chemistry》2021,57(12):1931-1939
Russian Journal of Organic Chemistry - A procedure has been developed for the synthesis of highly functionalized tetracyclic diterpenoids from natural ent-kaur-16-en-19-oic acid under modified... 相似文献