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排序方式: 共有578条查询结果,搜索用时 31 毫秒
1.
The paper proposes a rational method to derive fairness measures for surfaces. It works in cases where isophotes, reflection lines, planar intersection curves, or other curves are used to judge the fairness of the surface. The surface fairness measure is derived by demanding that all the given curves should be fair with respect to an appropriate curve fairness measure. The method is applied to the field of ship hull design where the curves are plane intersections. The method is extended to the case where one considers, not the fairness of one curve, but the fairness of a one parameter family of curves. Six basic third order invariants by which the fairing measures can be expressed are defined. Furthermore, the geometry of a plane intersection curve is studied, and the variation of the total, the normal, and the geodesic curvature and the geodesic torsion is determined. 相似文献
2.
Hsien-Chung Wu 《Fuzzy Optimization and Decision Making》2003,2(1):61-73
The concept of fuzzy scalar (inner) product that will be used in the fuzzy objective and inequality constraints of the fuzzy primal and dual linear programming problems with fuzzy coefficients is proposed in this paper. We also introduce a solution concept that is essentially similar to the notion of Pareto optimal solution in the multiobjective programming problems by imposing a partial ordering on the set of all fuzzy numbers. We then prove the weak and strong duality theorems for fuzzy linear programming problems with fuzzy coefficients. 相似文献
3.
The 11 800-14 380 cm−1 frequency range has been scanned for rotationally resolved rovibronic transitions in the A2B2-X2A1 electronic band system of the symmetric (C2v) 16O14N16O and 18O14N18O isotopologues and in the corresponding electronic band system of the asymmetric (Cs) 18O14N16O isotopologue. The rotational analysis—reflecting minor differences in mass—in combination with symmetry induced spectral differences allows an identification of 68 16O14N16O vibronic levels, 26 18O14N18O vibronic levels and 51 18O14N16O vibronic levels. The bands are recorded using near infrared fluorescence spectroscopy and a piezo valve based pulsed molecular beam expansion of premixed 18O2 and 14N16O in Ar. The majority of the observed bands is rotationally assigned and can be identified as transitions starting from the vibrational ground state of one of the isotopologues. Numerous hot bands have also been identified. A comparison of the overall spectroscopic features of C2v vs. Cs symmetric species provides qualitative information on symmetry dependence of vibronic couplings. 相似文献
4.
Xia Chen 《Journal of Theoretical Probability》2006,19(3):721-739
We establish moderate and small deviations for the ranges of integer valued random walks. Our theorems apply to the limsup
and the liminf laws of the iterated logarithm.
We establish moderate and small deviations for the ranges of integer valued random walks. Our theorems apply to the limsup
and the liminf laws of the iterated logarithm. 相似文献
5.
6.
H-空间与拟向量变分不等式 总被引:2,自引:0,他引:2
本在Hausdorff locally convex H-空间上建立了一个新的不动点定理;利用局部交性质,在Hausdorff locally convex H-空间上建立了相应的拟向量变分不等式. 相似文献
7.
8.
9.
The photochemical reaction channels of cyclobutanone have been studied at the CASSCF level with a 6‐31G* basis set. Starting from the n‐π* excited‐state (S1) cyclobutanone, the three reactions can take place: decarbonylation (produce CO and cyclopropane or propylene), cycloelimination (produce ketene and ethylene), and ring expansion (produce oxacarbene). Our computation indicates that decarbonylation products CO and triplet trimethylene are formed on the triplet n‐π* excited state (T1) in a stepwise way via a biradical intermediate after intersystem crossing (ISC) to T1 from S1. And, then, the triplet trimethylene undergoes a second ISC to the ground state (S0) to produce the singlet trimethylene from which cyclopropane can be produced rapidly only overcoming a 1 to 2‐kcal/mol barrier while propylene can be formed as a secondary product. The cycloelimination products ketene and ethylene are formed on the S0 in a concerted mechanism after internal conversion (IC) to S0 from S1 via a biradical conical intersection. The reaction channels corresponding to ring expansion on the S0, T1, and S1 states have also been discussed, and the likeliest reaction path is that oxacarbene is formed on the ground state following S1/S0 internal conversion. The surface topology of cyclobutanone on the S1 surface is characterized by a transition state separating the minimum from the S1/S0 conical intersection, which is consistent with the previous computations and can explain the wavelength dependence of the fluorescence emission yield. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2004 相似文献
10.
G. Gopalakrishnan Nair 《Journal of Optimization Theory and Applications》1979,28(3):429-434
The convergence of the Luus-Jaakola search method for unconstrained optimization problems is established.Notation
E
n
Euclideann-space
- f
Gradient off(x)
- 2
f
Hessian matrix
- (·)
T
Transpose of (·)
-
I
Index set {1, 2, ...,n}
- [x
i1
*(j)
]
Point around which search is made in the (j + 1)th iteration, i.e., [x
1l
*(j)
,x
2l
*(j)
,...,x
n1
*(j)
]
-
r
i
(i)
Range ofx
il
*(i)
in the (j + 1)th iteration
-
l
1
mini {r
i
(0)
}
-
l
2
mini {r
i
(0)
}
-
A
j
Region of search in thejth iteration, i.e., {x E
n:x
il
*(j-1)
–0.5r
i
(j-1)
x
ix
il
*(j-1)
+0.5r
i
(j-1)
,i I}
-
S
j
Closed sphere with center origin and radius
j
-
Reduction factor in each iteration
-
1–
- (·)
Gamma function
Many discussions with Dr. S. N. Iyer, Professor of Electrical Engineering, College of Engineering, Trivandrum, India, are gratefully acknowledged. The author has great pleasure to thank Dr. K. Surendran, Professor, Department of Electrical Engineering, P.S.G. College of Technology, Coimbatore, India, for suggesting this work. 相似文献