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ZHANG WenlingDepartment of Mathematics Physics National Natural Science Foundation of China Beijing China 《中国科学A辑(英文版)》2004,(6)
We use qualitative analysis and numerical simulation to study peaked traveling wave solutions of CH-γ and CH equations. General expressions of peakon and periodic cusp wave solutions are obtained. Some previous results become our special cases. 相似文献
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Some previous works show that symmetric fixed- and variable-stepsize linear multistep methods for second-order systems which do not have any parasitic root in their first characteristic polynomial give rise to a slow error growth with time when integrating reversible systems. In this paper, we give a technique to construct variable-stepsize symmetric methods from their fixed-stepsize counterparts, in such a way that the former have the same order as the latter. The order and symmetry of the integrators obtained is proved independently of the order of the underlying fixed-stepsize integrators. As this technique looks for efficiency, we concentrate on explicit linear multistep methods, which just make one function evaluation per step, and we offer some numerical comparisons with other one-step adaptive methods which also show a good long-term behaviour.
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Todd Rowland 《Complexity》2006,12(2):13-29
We present a network experiment that investigates the computational power of cellular automata on the simplest irregular lattice. One cellular automaton whose apparent complexity increased is Rule 60, the left neighbor Xor operator. It went from being nested to complex. That makes Xor a candidate for universal computational power. We present the evidence in terms of the size of cycle lengths, transients, and size of boolean expressions. © 2006 Wiley Periodicals, Inc. Complexity 12: 13–29, 2006 相似文献
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Mary E. R. McHale Ann-Sofi M. Kauppila Joyce R. Powell Pablo Otero Jr. Melani Jayasekera William E. Acree Jr. 《Journal of solution chemistry》1996,25(3):295-302
Experimental solubilities are reported for benzil dissolved in six binary mixtures containing dibutyl ether with hexane, heptane, octane, cyclohexane, methylcyclohexane, and 2,2,4-trimethylpentane at 25°C. Results of these measurements are compared to the predictions of equations developed previously for solubility in systems of nonspecific interactions. The most successful equation in terms of goodness of fit involved a volume fraction average of the excess Gibbs energies relative to the Flory-Huggins model, and predicted the experimental solubilities in the six systems studied to within an overall average absolute deviation of 3.4% and with a maximum deviation of 6.0%. 相似文献
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本文给出了算子方程AXB-X=C可解的若干充要条件,其中(A,B)为下列情形之一:A或B有闭值域;A(B*)有闭值域并且是单射或者相似于一个协亚正规算子并且B(A*)是单侧移位;A+(B(*+))幂有界,其值域R(A+) R(A)(R(B) R(B+)并且B(A*)是单侧移位;A=U*且B=U是Hardy空间上重数为1的单侧移位.而且,给出了解的表达式. 相似文献
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For an accurate simulation of forming processes, it is of paramount importance to model the different lubrication regimes that can develop at the contact interface. These might vary from zone to zone of the forming piece, and from one regime to another, resulting in forces of different nature and magnitude. In these cases, the use of the classical Coulomb friction law will be clearly not sufficient to capture, in a suitable manner, the variety of forces applied on the forming piece. 相似文献
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In this paper we design higher-order time integrators for systems of stiff ordinary differential equations. We combine implicit Runge–Kutta and BDF methods with iterative operator-splitting methods to obtain higher-order methods. The idea of decoupling each complicated operator in simpler operators with an adapted time scale allows to solve the problems more efficiently. We compare our new methods with the higher-order fractional-stepping Runge–Kutta methods, developed for stiff ordinary differential equations. The benefit is the individual handling of each operator with adapted standard higher-order time integrators. The methods are applied to equations for convection–diffusion reactions and we obtain higher-order results. Finally we discuss the applications of the iterative operator-splitting methods to multi-dimensional and multi-physical problems. 相似文献