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71.
Polycyclic aromatic hydrocarbons when treated with iodine monochloride in water solutions of sulfuric acid afford iodo- and chloroderivatives. Biphenyl, fluorene, acenaphthene, 1-nitronaphthalene undergo iodination. Naphthalene furnishes a mixture of iodo- and chloroderivatives, prevailing the latter. Anthracene and phenanthrene provide only chlorinated products. The iodine monochloride in the sulfuric acid is a stronger iodinating agent than in acetonitrile. 相似文献
72.
A. Zh. Kassanova E. A. Krasnokutskaya V. D. Filimonov 《Russian Chemical Bulletin》2016,65(11):2559-2567
The methods for the synthesis of pyridinyl trifluoromethanesulfonates are reviewed. Examples of their use in organic synthesis for the production of valuable products are presented. 相似文献
73.
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75.
A. A. Dorozhkin A. V. Filimonov A. P. Kovarskii Yu. A. Kudryavtsev N. N. Petrov 《Technical Physics》1997,42(9):1091-1093
Results are presented from an experimental investigation of layered structures made up of elements with strongly different
atomic masses, using ion sputtering with post-ionization of secondary neutrals in a gas discharge plasma. An anomalous increase
of the signal at boundaries between layers is noted. It is proposed that the phenomenon of selectivity in etching affects
the measurement of the profile of secondary particle yield.
Zh. Tekh. Fiz. 67, 120–122 (September 1997) 相似文献
76.
We present a general method for the linear least-squares solutionof overdetermined and underdetermined systems. The method isparticularly efficient when the coefficient matrix is quasi-square,that is when the number of rows and number of columns is almostthe same. The numerical methods for linear least-squares problemsand minimum-norm solutions do not generally take account ofthis special characteristic. The proposed method is based onLU factorization of the original quasi-square matrix A, assumingthat A has full rank. In the overdetermined case, the LU factorsare used to compute a basis for the null space of AT. The right-handside vector b is then projected onto this subspace and the least-squaressolution is obtained from the solution of this reduced problem.In the case of underdetermined systems, the desired solutionis again obtained through the solution of a reduced system.The use of this method may lead to important savings in computationaltime for both dense and sparse matrices. It is also shown inthe paper that, even in cases where the matrices are quite small,sparse solvers perform better than dense solvers. Some practicalexamples that illustrate the use of the method are included. 相似文献
77.
V. D. Filimonov Yu. Yu. Kulmanakova M. S. Yusubov I. A. Perederina Ki-Whan Chi O. Kh. Poleshchuk 《Russian Journal of Organic Chemistry》2004,40(7):917-923
Alkali metal halides NaF, KCl, and KBr sharply enhance the nitrating activity of sodium nitrate in acetic acid with respect to 9-methylcarbazole. In the presence of KI and KBr, both nitration and halogenation of the substrate occurs, while KCl and NaF promote only the nitration process. The results may be interpreted in terms of formation of the corresponding nitryl halides XNO2 (X = F, Cl, Br, I) whose structure and reactivity were examined in the framework of the density functional theory (DFT B3LYP/3-21G*). 相似文献
78.
V. A. Filimonov 《Russian Physics Journal》1989,32(4):295-297
The binding energies of double hypernuclei are calculated as a function of mass number. Estimates are made for the width of the -hyperon decay channel of double hypernuclei. Significant suppression of this channel due to -to- conversion is found in heavy hypernuclei.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 70–73, April, 1989. 相似文献
79.
A.V. Rudik A.V. Dmitriev A.A. Lagunin D.A. Filimonov V.V. Poroikov 《SAR and QSAR in environmental research》2019,30(10):751-758
ABSTRACTMetabolite identification is an essential part of the drug discovery and development process. Experimental methods allow identifying metabolites and estimating their relative amount, but they require cost-intensive and time-consuming techniques. Computational methods for metabolite prediction are devoid of these shortcomings and may be applied at the early stage of drug discovery. In this study, we investigated the possibility of creating SAR models for the prediction of the qualitative metabolite yield (‘major’, ‘minor’, ”trace” and ”negligible”) depending on species and biological experimental systems. In addition, we have created models for prediction of xenobiotic excretion depending on its administration route for different species. The prediction is based on an algorithm of naïve Bayes classifier implemented in PASS software. The average accuracy of prediction was 0.91 for qualitative metabolite yield prediction and 0.89 for prediction of xenobiotic excretion. The created models were included as a component of MetaTox web application, which allows predicting the xenobiotic metabolism pathways (http://www.way2drug.com/mg). 相似文献
80.