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961.
An efficient fast Fourier transform method has been employed to determine correlation function [g(r*)] using the structure factor [S(Q*)] calculated with the rescaled mean spherical approximation (RMSA) and the DLVO potential. Based on this function a parametric
(size and charge) study of the ordering in a highly charged and concentrated macroions (an ideal colloid) has been made. The
strength of the correlation increases with the increase in the charge on macroions and it saturates after acertain value.
Similarly, a critical diameter of the particle depending on the charge on it has been found at which normal feature of the
ordering disappears. 相似文献
962.
利用渐近方法和对角化技巧研究了伴有边界摄动的高维非线性系统边值问题的奇摄动,在适当的假设下,证得摄动问题解的存在并导出其解关于ε的高阶近似. 相似文献
963.
若干二维问题的WKB近似能级 总被引:2,自引:0,他引:2
讨论了二维空间的WKB近似方法,导出了Bohr-Sommerfeld量子化条件,并计算了若干具体问题的能级,包括中心势情况和Aharonov-Bohm势加中心势情况。 相似文献
964.
T. Zaimi 《Acta Mathematica Hungarica》2002,96(4):309-325
Let 1<q<2 be a real number, m≥1 be a rational integer and lm(q)={|P(q)|,P∈Z[X],P(q)≠0,H(P)≤m}, where Z[X] denotes the set of polynomials P with rational integer coefficients and H(P)
is the height of P. The value of lm(q) was determined for many particular Pisot numbers ([3] and [7]). In this paper we determine the infimum and the supremum
of the numbers lm(q) for any fixed m. We also determine the greatest limit point for the case m=1.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
965.
U. Luther 《Annali di Matematica Pura ed Applicata》2003,182(2):161-200
We show that the representation theorem for classical approximation spaces can be generalized to spaces A(X,l
q
(ℬ))={f∈X:{E
n
(f)}∈l
q
(ℬ)} in which the weighted l
q
-space l
q
(ℬ) can be (more or less) arbitrary. We use this theorem to show that generalized approximation spaces can be viewed as real
interpolation spaces (defined with K-functionals or main-part K-functionals) between couples of quasi-normed spaces which satisfy certain Jackson and Bernstein-type inequalities. Especially,
interpolation between an approximation space and the underlying quasi-normed space leads again to an approximation space.
Together with a general reiteration theorem, which we also prove in the present paper, we obtain formulas for interpolation
of two generalized approximation spaces.
Received: December 6, 2001; in final form: April 2, 2002?Published online: March 14, 2003 相似文献
966.
The recent generalized gradient approximation (GGA) density functional OCS1 of Handy and Cohen is implemented in the deMon code and tested on a carefully selected set of problems. OCS1 is found to be accurate for molecular atomization energies, transition metal–ligand bonds, and systems with intramolecular hydrogen bonds. However, OCS1 encounters problems for systems with intermolecular hydrogen bonds. It also tends to elongate bond lengths systematically, and sometimes significantly. The OPTX exchange is combined with three meta‐GGA correlation functionals, Lap3, τ1, and τ2, the latter reported for the first time. The new meta‐GGA scheme OPTX exchange plus τ2 correlation called Oτ2 yields improved molecular geometries, NMR shielding constants, and an improved barrier height for the H+H2 reaction. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2006 相似文献
967.
For a sequence of partial sums ofd-dimensional independent identically distributed random vectors a corresponding multivariate renewal process is defined componentwise. Via strong invariance together with an extreme value limit theorem for Rayleigh processes, a number of weak asymptotic results are established for thed-dimensional renewal process. Similar theorems for the estimated version of this process are also derived. These results are suggested to serve as simultaneous asymptotic testing devices for detecting changes in the multivariate setting. 相似文献
968.
A Detection Algorithm for the localisation of unknown fault lines of a surface from scattered data is given. The method is
based on a local approximation scheme using thin plate splines, and we show that this yields approximation of second order
accuracy instead of first order as in the global case. Furthermore, the Detection Algorithm works with triangulation methods,
and we show their utility for the approximation of the fault lines. The output of our method provides polygonal curves which
can be used for the purpose of constrained surface approximation.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
969.
本文对一般形式的线性Fredholm积-微分方程推导出迭代Galerkin解及其导数的渐近展式,从而得到了迭代解的外推估计,同时还获得了理想的校正结果. 相似文献
970.
Cristina Bazgan W. Fernandez de la Vega Marek Karpinski 《Random Structures and Algorithms》2003,23(1):73-91
It is known that large fragments of the class of dense Minimum Constraint Satisfaction (MIN‐CSP) problems do not have polynomial time approximation schemes (PTASs) contrary to their Maximum Constraint Satisfaction analogs. In this paper we prove, somewhat surprisingly, that the minimum satisfaction of dense instances of kSAT ‐formulas, and linear equations mod 2, Ek‐LIN2, do have PTASs for any k. The MIN‐Ek‐LIN2 problems are equivalent to the k‐ary versions of the Nearest Codeword problem, the problem which is known to be exceedingly hard to approximate on general instances. The method of solution of the above problems depends on the development of a new density sampling technique for k‐uniform hypergraphs which could be of independent interest. © 2003 Wiley Periodicals, Inc. Random Struct. Alg., 23: 73–91, 2003 相似文献