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951.
The Nash equilibrium in pure strategies represents an important solution concept in nonzero sum matrix games. Existence of
Nash equilibria in games with known and with randomly selected payoff entries have been studied extensively. In many real
games, however, a player may know his own payoff entries but not the payoff entries of the other player. In this paper, we
consider nonzero sum matrix games where the payoff entries of one player are known, but the payoff entries of the other player
are assumed to be randomly selected. We are interested in determining the probabilities of existence of pure Nash equilibria
in such games. We characterize these probabilities by first determining the finite space of ordinal matrix games that corresponds
to the infinite space of matrix games with random entries for only one player. We then partition this space into mutually
exclusive spaces that correspond to games with no Nash equilibria and with r Nash equilibria. In order to effectively compute the sizes of these spaces, we introduce the concept of top-rated preferences
minimal ordinal games. We then present a theorem which provides a mechanism for computing the number of games in each of these
mutually exclusive spaces, which then can be used to determine the probabilities. Finally, we summarize the results by deriving
the probabilities of existence of unique, nonunique, and no Nash equilibria, and we present an illustrative example. 相似文献
952.
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In a previous paper [Physica D 141 (3–4) (2000) 316], the inverse problem for wave crests was introduced and a solution strategy for two-wave interactions was given. Here these solutions are actually constructed, in particular for the cases with small interaction angle, moderate phase shifts, and/or symmetric interactions. Two detailed examples are presented and analyzed. The sensitivity of the method is investigated, and conclusions about the practical applicability are given. 相似文献
955.
956.
957.
High-speed particle image velocimetry (PIV) and planar laser induced fluorescence (PLIF) techniques are combined to acquire
flow field and fuel concentration in a spray-guided spark-ignited direct-injection (SG-SIDI) engine under motored and fired
operation. This is a crucial step to enable studies that seek correlations between marginal engine operation (misfires or
partial burns) and local, instantaneous mixture and flow conditions. Correlated flow and fuel data are extracted from a 4 mm×4 mm
sub-region directly downstream the spark plug to characterize the in-cylinder conditions next to the spark plug during the
spray and ignition event. Values of equivalence ratio, velocity magnitude, shear strain rate, and vorticity all increase during
the spray event and decrease an order of magnitude during the duration of the spark event. 相似文献
958.
I Nakagawa J Shaw S Churchwell X Jiang B Asavapibhop M C Berisso P E Bosted K Burchesky F Casagrande A Cichocki R S Hicks A Hotta T Kobayashi R A Miskimen G A Peterson S E Rock T Suda T Tamae W Turchinetz K Wang 《Physical review letters》2001,86(24):5446-5449
New electron scattering measurements have been made that extend data on the (3)He elastic magnetic form factor up to Q(2) = 42.6 fm(-2). These new data test theoretical conjectures regarding non-nucleonic effects in the three-body system. The very small cross sections, as low as 10(-40) cm(2)/sr, required the use of a high-pressure cryogenic gas target and a detector system with excellent background rejection capability. No existing theoretical calculation satisfactorily accounts for all the available data. 相似文献
959.
Julian Tu Dennis Svatunek Saba Parvez Albert C. Liu Brian J. Levandowski Hannah J. Eckvahl Randall T. Peterson Kendall N. Houk Raphael M. Franzini 《Angewandte Chemie (International ed. in English)》2019,58(27):9043-9048
The isocyano group is a structurally compact bioorthogonal functional group that reacts with tetrazines under physiological conditions. Now it is shown that bulky tetrazine substituents accelerate this cycloaddition. Computational studies suggest that dispersion forces between the isocyano group and the tetrazine substituents in the transition state contribute to the atypical structure–activity relationship. Stable asymmetric tetrazines that react with isonitriles at rate constants as high as 57 L mol?1 s?1 were accessible by combining bulky and electron‐withdrawing substituents. Sterically encumbered tetrazines react selectively with isonitriles in the presence of strained alkenes/alkynes, which allows for the orthogonal labeling of three proteins. The established principles will open new opportunities for developing tetrazine reactants with improved characteristics for diverse labeling and release applications with isonitriles. 相似文献
960.
The effect of frequency and power density on the ultrasonically-enhanced killing of biofilm-sequestered Escherichia coli 总被引:2,自引:0,他引:2
Infection on implanted medical devices is a critical concern because the bacteria are recalcitrant to antibiotic therapy; currently the only way to eliminate the infection is to remove the device. We have found that low-frequency ultrasound renders bacteria more susceptible to antibiotics. The effect of low-intensity ultrasound on the enhancement of antibiotic action against biofilm bacteria was measured by subjecting thick E. coli biofilms for 2 h at 37°C to one of four conditions: (1) incubation in nutrient broth; (2) incubation in nutrient broth with antibiotic; (3) ultrasonication in nutrient broth without antibiotic; and (4) ultrasonication in nutrient broth with antibiotic. Two frequencies (70 and 500 kHz) and several ultrasonic intensities were examined, ranging from 2 to 200 mW/cm2. It was determined that low-intensity ultrasound significantly enhanced killing of biofilm E. coli by gentamicin. This enhancement increased with increasing ultrasonic intensity and decreased with increasing frequency. A mathematical model of ultrasonically-enhanced transport in cylindrical pores and channels shows that gentamicin transport increases with ultrasonic intensity and decreases with increasing frequency. However, the magnitude of increased transport is so small that it is difficult to attribute enhanced killing of bacteria to enhanced antibiotic transport through the pores and channels of the biofilm; therefore, other mechanisms must play a role. The use of low-intensity ultrasound in conjunction with antibiotic treatment may prove to be a viable clinical method of eliminating biofilm infections from the surfaces of implanted medical devices. 相似文献