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81.
J. Raul Alvarez-Idaboy Annia Galano Luis A. Montero Ricardo Martínez 《Journal of polymer science. Part A, Polymer chemistry》1992,30(12):2497-2502
SCF ab initio and AM1 semiempirical calculations with full geometry optimization have been carried out to model the initial steps of alkenylfuran cationic polymerization. Semiempirical procedures have been used to model propagation steps. Proton affinities of the relevant neutral species as well as the heats of formation of probable dimers were calculated. The results allow the explanation of the experimental behavior. The capabilities of the employed methods to describe these type of processes is discussed. It is confirmed that competition between vinyl and ring site attacks is the most important feature in these systems. © 1992 John Wiley & Sons, Inc. 相似文献
82.
Raul Cordovil 《Journal of Combinatorial Theory, Series B》1983,34(2):209-223
A natural sufficient condition for a finite family of single element extensions of a matroid to be compatible is given. Characterizations of all the finite extensions N of a matroid M(E) are given for which the rank function satisfies or equivalently the closure operator satisfies . The single element extensions and the principal extensions are examples of such matroids. The notion of a sheaf of flats of M. Las Vergnas is used in the proof of a new necessary and sufficient condition for two single element extensions of a matroid to be compatible. An initial announcement of part of these results appeared in R. Cordovil (C. R. Acad. Sci. Paris. A284 (1977), 1249–1252). 相似文献
83.
Fernanda M. B. Coutinho Luis C. Rezende Raul Quijada 《Journal of polymer science. Part A, Polymer chemistry》1986,24(4):727-735
A comparative kinetic study of the reaction of three different hydroxylated liquid polybutadienes (M n ? 3000) — R - 45M, R-45HT, and H-034—and tolylene diisocyanate (TDI), was carried out in toluene solution. An analytical method was used to follow the kinetics of the reactions at four different temperatures. The reactions presented an apparent second-order rate law. In the second-order plots, a discontinuity was observed. The R-45M polybutadiene was about twice more reactive than R-45HT and H-034; these latter two polybutadienes presented similar reactivities. 相似文献
84.
Dr. Edlira Suljoti Raul Garcia‐Diez Dr. Sergey I. Bokarev Dr. Kathrin M. Lange Roland Schoch Brian Dierker Marcus Dantz Kenji Yamamoto Nicholas Engel Dr. Kaan Atak Prof. Dr. Oliver Kühn Prof. Dr. Matthias Bauer Prof. Dr. Jan‐Erik Rubensson Prof. Dr. Emad F. Aziz 《Angewandte Chemie (International ed. in English)》2013,52(37):9841-9844
85.
86.
Raul SanMartín Roberto Olivera Luisa Carrillo Imanol Tellitu Maria Dolores Badía Esther Domínguez 《合成通讯》2013,43(10):1643-1652
A comparative study of the oxidation of 3-aryl-4-hydroxytetrahydroisoquinolines has been carried out. A modification of the Jones conditions turn out to be the best methodology for the regioselective preparation of target 4-isoquinolinone derivatives. 相似文献
87.
88.
Pavel Drábek Petr Girg Raul Manásevich 《NoDEA : Nonlinear Differential Equations and Applications》2001,8(3):285-298
In this paper we give a generic necessary and sufficient condition for the solvability of?
Received November 1999 相似文献
89.
The fundamental parameter (FP) method was extended to account for the geometrical details of experimental x‐ray fluorescence (XRF) detection. In the traditional FP method the primary fluorescence photons have parallel pathways towards the detector. In the new approach the primary fluorescence photons can travel in any direction which allows them to reach the detector if not absorbed or scattered. The derived XRF signal equation explicitly depends on the length of the collimator in front of the detector, the detector size, position and orientation. An algorithm which numerically calculates the XRF signal for any set of parameters was developed and implemented for the Kα XRF signal of arsenic in skin. Optimal positions and orientations of the detector and collimator ensemble which maximize the XRF signal were found. Results and limitations of the method were also discussed. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
90.
Nemallapudi Bakthavatchala Reddy Grigory V. Zyryanov Guda Mallikarjuna Reddy Avula Balakrishna Adivireddy Padmaja Venkatapuram Padmavathi Cirandur Suresh Reddy Jarem Raul Garcia Gundala Sravya 《Journal of heterocyclic chemistry》2019,56(2):589-596
A new class of bis heterocycles‐benzimidazolyl pyrazoles were prepared from the Michael acceptor (E)‐3‐(1H‐benzimidazol‐2‐yl)‐1‐aryl‐prop‐2‐en‐1‐one. The thiamide group was exploited to develop thiazole ring on treatment with p‐fluorophenacyl bromide to get tris heterocycles. All the lead compounds were tested for antimicrobial activity. The compound 7d having nitro substituent on the aromatic ring showed greater antimicrobial activity particularly against Pseudomonas aeruginosa and Penicillium chrysogenum. 相似文献