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911.
F. G. Valeeva D. A. Kuryashov S. V. Zakharov G. I. Vagapova E. A. Vasilieva N. Yu. Bashkirtseva L. Ya. Zakharova A. I. Konovalov 《Russian Chemical Bulletin》2013,62(4):989-993
The system based on the cationic surfactant 4-aza-1-hexadecyl-1-azoniabicyclo[2.2.2]-octane bromide (DABCO-16) and the organic electrolyte sodium salicylate was studied by tensiometry, conductometry, pH-metry, dynamic and electrophoretic light scattering, and viscosimetry. The critical concentration of micelle formation of DABCO-16 and the electrokinetic potential decrease sharply and the hydrodynamic diameter of the aggregates increases as the concentration of sodium salicylate increases. The rheological properties of the studied solutions are well described by the Maxwell model for a viscoelastic liquid with one relaxation time. Aqueous solutions DABCO-16—sodium salicylate exhibit the properties of an elastic gel and can be used for the formation of compositions with the improved rheological properties. 相似文献
912.
913.
Several settings, where the notion of virtual age is employed, are discussed. We argue that the age reduction imperfect repair modeling is often not sufficiently justified in practice, as it is not possible to execute repair in most of real situations that conforms with this model. On the other hand, a shock‐based virtual age model is suggested and justified via the probabilities of failures on shocks. The new notion of virtual age for degrading items is also introduced. We discuss how to recalculate virtual age after switching from one regime to another. Several examples illustrating different notions of virtual age are presented. 相似文献
914.
915.
It is proved that the group Sp10(ℤ) is generated by an involution and an element of order 3. 相似文献
916.
Molecular dynamics simulations combining many microsecond trajectories have recently predicted that a very fast folding protein like lambda repressor fragment λ(6-85) D14A could have a slow millisecond kinetic phase. We investigated this possibility by detecting temperature-jump relaxation to 5 ms. While λ(6-85) D14A has no significant slow phase, two even more stable mutants do. A slow phase of λ(6-85) D14A does appear in mild denaturant. The experimental data and computational modeling together suggest the following hypothesis: λ(6-85) takes only microseconds to reach its native state from an extensively unfolded state, while the latter takes milliseconds to reach compact β-rich traps. λ(6-85) is not only thermodynamically but also kinetically protected from reaching such "intramolecular amyloids" while folding. 相似文献
917.
Maxim E. Kukushkin Dmitriy A. Skvortsov Marina A. Kalinina Viktor A. Tafeenko Vladimir V. Burmistrov Gennady M. Butov 《Phosphorus, sulfur, and silicon and the related elements》2020,195(7):544-555
AbstractAn effective and highly regio- and diastereoselective one-pot synthesis of two types of dispiro heterocyclic systems (2-thioxodispiro[imidazolidine-4,3′-pyrrolidine-2′,3″-indoline]-2″,5-diones and 2-thioxodispiro[imidazolidine-4,3′-pyrrolidine-4′,3″-indoline]-2″,5-diones) comprising pyrrolidinyl-oxindole, thiohydantoin and adamantane moieties has been developed based on a 1,3-dipolar cycloaddition of azomethine ylides, generated from isatin and sarcosine or formaldehyde and sarcosine, to adamantane-containing electron-deficient alkenes. Several molecules have demonstrated a considerable cytotoxicity against A549, HEK293T, MCF7 and VA13 cancer cell lines. The possible mechanism of anticancer activity of the synthesized compounds based on literature data may be the inhibition of p53/MDM2 interaction; however, we did not observe significant p53 activation using a reporter construction in A549 cell line in the relevant concentration range. 相似文献
918.
Zakharov M. A. Filatova Yu. V. Bykov M. A. Avramenko N. V. Aslanov L. A. 《Russian Journal of Coordination Chemistry》2020,46(4):268-275
Russian Journal of Coordination Chemistry - Protic metal-containing ionic liquids with the diethanolammonium cation (HO–CH2–CH2)2$${\text{NH}}_{{\text{2}}}^{ + }$$ (DEAH+) and anions... 相似文献
919.
Trevor A. Shear Fuding Lin Lev N. Zakharov Darren W. Johnson 《Angewandte Chemie (International ed. in English)》2020,59(4):1496-1500
Cyclophanes are a venerable class of macrocyclic and cage compounds that often contain unusual conformations, high strain, and unusual properties. However, synthesis of complex, functional derivatives remains difficult due to low functional group tolerance, high dilution, extreme reaction conditions, and sometimes low yields using traditional stepwise synthetic methods. “Design of experiments” (DOE) is a method employed for the optimization of reaction conditions, and we showcase this approach to generate a dramatic increase in the yield of specific targets from two different self‐assembling systems. These examples demonstrate that DOE provides an additional tool in tuning self‐assembling, dynamic covalent systems. 相似文献
920.
Sergey V. Ovsyannikov Maxim Bykov Sergey A. Medvedev Pavel G. Naumov Anton Jesche Alexander A. Tsirlin Elena Bykova Irina Chuvashova Alexander E. Karkin Vadim Dyadkin Dmitry Chernyshov Leonid S. Dubrovinsky 《Angewandte Chemie (International ed. in English)》2020,59(14):5632-5636
Functional oxides whose physicochemical properties may be reversibly changed at standard conditions are potential candidates for the use in next‐generation nanoelectronic devices. To date, vanadium dioxide (VO2) is the only known simple transition‐metal oxide that demonstrates a near‐room‐temperature metal–insulator transition that may be used in such appliances. In this work, we synthesized and investigated the crystals of a novel mixed‐valent iron oxide with an unconventional Fe5O6 stoichiometry. Near 275 K, Fe5O6 undergoes a Verwey‐type charge‐ordering transition that is concurrent with a dimerization in the iron chains and a following formation of new Fe?Fe chemical bonds. This unique feature highlights Fe5O6 as a promising candidate for the use in innovative applications. We established that the minimal Fe?Fe distance in the octahedral chains is a key parameter that determines the type and temperature of charge ordering. This model provides new insights into charge‐ordering phenomena in transition‐metal oxides in general. 相似文献