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991.
V. V. Dovlatyan É. N. Ambartsumyan G. S. Amazaspyan 《Chemistry of Heterocyclic Compounds》1996,32(1):75-77
New approaches have been developed for the application of cyanamino-sym-triazines in the synthesis of imidazolidinyl-sym-triazines. 相似文献
992.
A. S. Dmitriev 《Radiophysics and Quantum Electronics》1998,41(12):1013-1021
The chaotic synchronization phenomenon is studied from the information point of view. Synchronization of a chaos receiver
by a chaos source is considered as copy recovery of the chaotic signal transmitted by the source. The main idea of this paper
is to show that the necessary condition of chaotic synchronization is not the level of physical action of one system on another
but the transmission of a certain volume of information on the chaotic process and, therefore, the capacity of the “communication
channel” between the source and the receiver.
This work was presented at the Summer Workshop “Dynamic Days” (Nizhny Novgorod, June 30–July 2, 1998).
Institute of Radioengineering and Electronics of the Russian Academy of Sciences, Moscow, Russia. Translated from Izvestiya
Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 41, No. 12, pp. 1497–1509, December, 1998. 相似文献
993.
The resistance to slow crack growth (SCG) was measured in binary blends of high density polyethylene (HDPE) and 5–10% concentrations of model ethylene-butene random copolymers by measuring the time to failure (tf) under a constant stress intensity. An increase of tf with the addition of the copolymer if the copolymer could crystallize and the increase was greater the higher branch density. The copolymer with 117 branches/1000C could not crystallize and therefore its blend had a tf that was less than that of the HDPE. The fracture energies of the blends as determined by their resistance to SCG were compared with the energy by rapid fracture, Jc, as previously measured by Rhee and Crist. It is concluded that SCG is more sensitive to variations in the microstructure than is rapid fracture and that the differences in SCG behavior can be qualitatively explained in terms of the differences in microstructure of the blends. ©1995 John Wiley & Sons, Inc. 相似文献
994.
I. S. Kim N. L. Krussanova I. V. Alekseeva R. N. Smartt 《Radiophysics and Quantum Electronics》1998,41(2):94-98
A new approach to investigating the statistical relationship between certain solar features and recurrent wind streams is
presented. This approach is based, on a comparative analysis of the distributions of lifetimes of a set of solar features,
recurrent geomagnetic disturbances, and geomagnetic “calms.” Correlation coefficients of 0.81, 0.85, 0.79, and 0.77 are found
for the distributions of several solar features—filaments, large-scale magnetic fields, coronal features, and coronal holes,
respectively—and recurrent geomagnetic disturbances. A correlation factor of 0.97 between the distributions of geomagnetic
“calms” and active regions is found. The combined evidence indicates that no specific type of solar feature is responsible
for the recurrent stream activity. Rather, the configuration of the large-scale magnetic field of the Sun appears to control
the permanently existing corpuscular activity. Since prominences trace polarity division lines of the large-scale magnetic
field structure of the Sun, they have been checked as a possible general predictor of recurrent corpuscular activity; their
parameters could present the most reliable indices that relate closely with trends in geomagnetic disturbances. A comparative
analysis of cyclic variations of sunspot numbers, the total number of prominences, the relative number of low-height (<-20″)
prominences, and recurrent geomagnetic storms is made for solar cycle N16. The relative number of low-height prominences is
found to correlate broadly (0.83) with recurrent wind streams.
P. K. Shternberg State Astronomical Institute, Moscow, Russia; National Solar Observatory, Sacramento Peak, U.S. Published
in Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 41, No. 2, pp. 145–151, February, 1998. 相似文献
995.
996.
P. V. Rogovskii S. L. Panasyuk A. A. Evstratov S. I. Kol'tsov 《Theoretical and Experimental Chemistry》1993,28(3):220-223
ESR shows that V(IV) may occur in isolated or interacting vanadium-oxygen groups on the surfaces of catalytically active P-V and Ti-V-bearing silica gels; there is a relationship between the V(IV) content and the phthalic anhydride selectivity in the oxidation of o-xylene.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 28, No. 3, pp. 277–282, May–June, 1992. 相似文献
997.
998.
999.
Summary The liquid-liquid extraction of Mo(VI) from different acid solutions by zinc diethyldithiocarbamate in chloroform is described. This extractant allows the separation of nanogram to milligram quantities of Mo from even gram quantities of many other elements. The separation of Mo can be made selective by appropriate choice of the composition of the aqueous phase, by back-extraction of Mo and/or the coextracted elements, and by masking Mo with hydrogen peroxide. These techniques were adapted for the determination of Mo in several reference materials by radiochemical neutron activation analysis via 99Mo. 相似文献
1000.