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311.
We consider nonlocal boundary value problems for three harmonic functions each of which is defined in its own domain. A contact condition is posed on the common part of the boundaries of these domains, and the Dirichlet or Neumann data (or mixed boundary conditions) are given on the remaining parts of the boundary. We prove the unique solvability of these problems. 相似文献
312.
The corresponding aldehydes were obtained by oxidation of N-substituted 2-methylimidazo-[4,5-b]- and 2-methylimidazo[4,5-c]pyridines with selenium dioxide. Some of their properties and transformations were studied. 相似文献
313.
314.
315.
G. D. Kovaleva 《Journal of Mathematical Sciences》1978,9(4):551-562
Calculation of the complex roots of the dispersion equations by the sweep-out method is discussed for the case of SH waves in a layered inhomogeneous medium. The roots obtained define the phase speeds and the damping coefficients of interference waves as functions of the frequency. Results of numerical computations are given.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 42, pp. 162–173, 1974. 相似文献
316.
Galina F. Makhaeva Nadezhda V. Kovaleva Elena V. Rudakova Natalia P. Boltneva Sofya V. Lushchekina Irina I. Faingold Darya A. Poletaeva Yuliya V. Soldatova Raisa A. Kotelnikova Igor V. Serkov Anatoly K. Ustinov Alexey N. Proshin Eugene V. Radchenko Vladimir A. Palyulin Rudy J. Richardson 《Molecules (Basel, Switzerland)》2020,25(24)
New hybrids of 4-amino-2,3-polymethylenequinoline with different sizes of the aliphatic ring linked to butylated hydroxytoluene (BHT) by enaminoalkyl (7) or aminoalkyl (8) spacers were synthesized as potential multifunctional agents for Alzheimer’s disease (AD) treatment. All compounds were potent inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) with selectivity toward BChE. Lead compound 8c, 2,6-di-tert-butyl-4-{[2-(7,8,9,10- tetrahydro-6H-cyclohepta[b]quinolin-11-ylamino)-ethylimino]-methyl}-phenol exhibited an IC50(AChE) = 1.90 ± 0.16 µM, IC50(BChE) = 0.084 ± 0.008 µM, and 13.6 ± 1.2% propidium displacement at 20 μM. Compounds possessed low activity against carboxylesterase, indicating likely absence of clinically unwanted drug-drug interactions. Kinetics were consistent with mixed-type reversible inhibition of both cholinesterases. Docking indicated binding to catalytic and peripheral AChE sites; peripheral site binding along with propidium displacement suggest the potential of the hybrids to block AChE-induced β-amyloid aggregation, a disease-modifying effect. Compounds demonstrated high antioxidant activity in ABTS and FRAP assays as well as inhibition of luminol chemiluminescence and lipid peroxidation in mouse brain homogenates. Conjugates 8 with amine-containing spacers were better antioxidants than those with enamine spacers 7. Computational ADMET profiles for all compounds predicted good blood-brain barrier distribution (permeability), good intestinal absorption, and medium cardiac toxicity risk. Overall, based on their favorable pharmacological and ADMET profiles, conjugates 8 appear promising as candidates for AD therapeutics. 相似文献
317.
Nadezhda V. Usol'tseva Olga B. Akopova Antonina I. Smirnova Maria I. Kovaleva Natalia V. Bumbina Nataliia V. Zharnikova 《Phase Transitions》2017,90(8):800-807
ABSTRACTTwo series of star-shaped discotic compounds (A and B) were studied to establish the relationship between their molecular structure and mesogenity. Series A included 19 three-arm compounds with known mesomorphism. Series B consisted of 132 new compounds with unknown mesomorphism: pyromellitic and cyanuric acid derivatives, 5,5′-azo-bis-isophthalic and 4,4′-azodiphthalic acids and triphenylene derivatives. The columnar mesomorphism prediction data for both series were obtained using the original program СМР ChemCard. The prediction data for series A are in good agreement with the experimental results and the reliability of the prediction was estimated to be 89.5%. The same method was applied for series B. The prediction results were approved by the synthesis of individual representatives of series B. A good correlation of the prediction with the experimental data was revealed. 相似文献
318.
Lyudmila Novokshonova Natalia Kovaleva Irina Meshkova Tatiana Ushakova Vadim Krasheninnikov Tatiana Ladygina Ilia Leipunskii Alexey Zhigach Michail Kuskov 《Macromolecular Symposia》2004,213(1):147-156
Heterogenized activators - “support-H2O/AlR3” (where R=Me, iBu, support=montmorillonite, zeolite), synthesized directly on the support, form with metallocenes metal alkyl complexes highly active in olefin polymerization without the use of commercial methylaluminoxane (MAO). It was shown by the method of temperature programmed desorption with the application of mass-spectrometry (TPD-MS) that the aluminumorganic compound in support-H2O/AlR3 is in general similar to the structure of commercial MAO. The heterogenization of Zr-cenes on support-H2O/AlR3 is accompanied by the appearance of the energy non-uniformity of active sites. The activation energy of thermal destruction of active Zr-C bonds in the active sites of prepared catalysts changes in the range from 25 to 32 kcal/mol. 相似文献
319.
Igor S. Sharygin Alexander V. Golovin Alexey A. Tarasov Anna M. Dymshits Elizaveta Kovaleva 《Journal of Raman spectroscopy : JRS》2022,53(3):508-524
Identifying the composition of primary/primitive mantle melts is crucial for understanding the mantle's evolution and mantle-derived magmatism. Melt inclusions in mantle xenoliths provide key information about such melts. This study used confocal Raman spectroscopy to characterize mineral assemblage of unexposed crystallized secondary melt inclusions in the olivine from the xenoliths of the sheared garnet peridotites from the Bultfontein kimberlite pipe (Kimberley cluster, Kaapvaal Craton, South Africa). The studied peridotites originated from 112- to 146-km mantle depths. In total, 16 minerals were identified among daughter crysatls, which include carbonates (calcite, magnesite, dolomite), alkali carbonates (eitelite, nyerereite, gregoryite/natrite, K–Na–Ca–carbonate (K,Na)2Ca(CO3)2 (K analogue of nyerereite), alkali carbonates with additional anions (northupite, bradleyite, burkeite), alkali sulfates (glauberite, thenardite, aphthitalite), apatite, tetraferriphlogopite, and magnetite. Several more daughter minerals gave distinct Raman spectra, but they were not determined due to the lack of similar spectra in the databases. Carbonates are predominant among the daughter minerals in the melt inclusions. Many daughter minerals are rich in alkalis. These facts indicate that melt(s), parental for the inclusions, is alkali-rich carbonate in composition. Two possible models were suggested for the origin of these melt inclusions: (1) in situ fracturing of olivine and the mantle melt infiltration shortly before the sheared peridotites were entrained by the ascending kimberlitic magma; (2) infiltration of the transporting kimberlite melt into xenoliths during ascent. Both models imply that the alkali-rich carbonate melt(s) that interacted with peridotites originated at a greater depth than the entrapment level of studied xenoliths (>150 km), that is, at the base of the lithosphere or in the asthenosphere. This melt is genetically related to the kimberlite magmatism that formed the Bultfontein pipe and points at the alkali-rich carbonate composition of primary kimberlite melt. 相似文献