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Kyle M. Lambert Prof. Dr. James M. Bobbitt Sherif A. Eldirany Liam E. Kissane Rose K. Sheridan Zachary D. Stempel Francis H. Sternberg Prof. Dr. William F. Bailey 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(15):5156-5159
Synergism among several intertwined catalytic cycles allows for selective, room temperature oxidation of primary amines to the corresponding nitriles in 85–98 % isolated yield. This metal‐free, scalable, operationally simple method employs a catalytic quantity of 4‐acetamido‐TEMPO (ACT; TEMPO=2,2,6,6‐tetramethylpiperidine N‐oxide) radical and the inexpensive, environmentally benign triple salt oxone as the terminal oxidant under mild conditions. Simple filtration of the reaction mixture through silica gel affords pure nitrile products. 相似文献
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Ravi P. Agarwal Mircea Balaj Donal O’Regan 《Journal of Optimization Theory and Applications》2017,173(2):443-458
Our purpose in this paper is to present two methods for obtaining common fixed point theorems in topological vector spaces. Both methods combine an intersection theorem and a fixed point theorem, but the order in which they are applied differs. 相似文献
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Bryden A. F. Le Bailly Liam Byrne Vincent Diemer Mohammadali Foroozandeh Gareth A. Morris Jonathan Clayden 《Chemical science》2015,6(4):2313-2322
Although foldamers, by definition, are extended molecular structures with a well-defined conformation, minor conformers must be populated at least to some extent in solution. We present a quantitative analysis of these minor conformers for a series of helical oligomers built from achiral but helicogenic α-amino acids. By measuring the chain length dependence or chain position dependence of NMR or CD quantities that measure screw-sense preference in a helical oligomer, we quantify values for the decay constant of a conformational signal as it passes through the molecular structure. This conformational signal is a perturbation of the racemic mixture of M and P helices that such oligomers typically adopt by the inclusion of an N or C terminal chiral inducer. We show that decay constants may be very low (<1% signal loss per residue) in non-polar solvents, and we evaluate the increase in decay constant that results in polar solvents, at higher temperatures, and with more conformationally flexible residues such as Gly. Decay constants are independent of whether the signal originates from the N or the C terminus. By interpreting the decay constant in terms of the probability with which conformations containing a screw-sense reversal are populated, we quantify the populations of these alternative minor conformers within the overall ensemble of secondary structures adopted by the foldamer. We deduce helical persistence lengths for Aib polymers that allow us to show that in a non-polar solvent a peptide helix, even in the absence of chiral residues, may continue with the same screw sense for approximately 200 residues. 相似文献
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In this paper we study the existence of classical solutions for a class of abstract neutral integro-differential equation
with unbounded delay. A concrete application to partial neutral integro-differential equations is considered. 相似文献
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Frank R. Graziani Victor S. Batista Lorin X. Benedict John I. Castor Hui Chen Sophia N. Chen Chris A. Fichtl James N. Glosli Paul E. Grabowski Alexander T. Graf Stefan P. Hau-Riege Andrew U. Hazi Saad A. Khairallah Liam Krauss A. Bruce Langdon Richard A. London Andreas Markmann Michael S. Murillo David F. Richards Howard A. Scott Heather D. Whitley 《High Energy Density Physics》2012,8(1):105-131
We describe the status of a new time-dependent simulation capability for dense plasmas. The backbone of this multi-institutional effort – the Cimarron Project – is the massively parallel molecular dynamics (MD) code “ddcMD,” developed at Lawrence Livermore National Laboratory. The project’s focus is material conditions such as exist in inertial confinement fusion experiments, and in many stellar interiors: high temperatures, high densities, significant electromagnetic fields, mixtures of high- and low-Z elements, and non-Maxwellian particle distributions. Of particular importance is our ability to incorporate into this classical MD code key atomic, radiative, and nuclear processes, so that their interacting effects under non-ideal plasma conditions can be investigated. This paper summarizes progress in computational methodology, discusses strengths and weaknesses of quantum statistical potentials as effective interactions for MD, explains the model used for quantum events possibly occurring in a collision, describes two new experimental efforts that play a central role in our validation work, highlights some significant results obtained to date, outlines concepts now being explored to deal more efficiently with the very disparate dynamical timescales that arise in fusion plasmas, and provides a careful comparison of quantum effects on electron trajectories predicted by more elaborate dynamical methods. 相似文献