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71.
张卫国 《数学物理学报(A辑)》2003,23(6):679-691
该文通过适当代换并结合假设待定法,求出了具高阶非线性项的Liénard方程a″(ξ)+la(ξ)+ma\+\{2p+1\}(ξ)+na\+\{4p+1\}(ξ)=0的三类精确解. 据此求出了广义Ginzburg Landau方程、Rangwala Rao方程及若干 导数schr〖AKo¨D〗dinger型方程的孤波解和三角函数型周期波解. 相似文献
72.
A modified variable-coefficient projective Riccati equation mapping method is applied to (2 + 1)-dimensional Wick-type stochastic generalized Broer-Kaup system. With the help of Hermit transformation, we obtain a series of new exact stochastic solutions to the stochastic Broer-Kaup system in the white noise environment. 相似文献
73.
矩阵方程AXB=D的最小二乘Hermite解及其加权最佳逼近 总被引:1,自引:0,他引:1
本中,我们讨论了矩阵方程AXB=D的最小二乘Hermite解,通过运用广义奇异值分解(GSVD),获得了解的通式。此外,对于给定矩阵F,也得到了它的加权最佳逼近表达式。 相似文献
74.
Luttmann E Ensign DL Vaidyanathan V Houston M Rimon N Øland J Jayachandran G Friedrichs M Pande VS 《Journal of computational chemistry》2009,30(2):268-274
Implementation of molecular dynamics (MD) calculations on novel architectures will vastly increase its power to calculate the physical properties of complex systems. Herein, we detail algorithmic advances developed to accelerate MD simulations on the Cell processor, a commodity processor found in PlayStation 3 (PS3). In particular, we discuss issues regarding memory access versus computation and the types of calculations which are best suited for streaming processors such as the Cell, focusing on implicit solvation models. We conclude with a comparison of improved performance on the PS3's Cell processor over more traditional processors. 相似文献
75.
Scalable synthetic routes to β-amino acids 1 and 2 are presented. These two compounds, which bind to the α2δ subunit of calcium channels and have important medical applications, have been prepared on kilogram scale in our pilot plant through an improved synthesis that avoids the use of highly toxic reagents and hazardous chemistry present in the original Medicinal Chemistry route. The two chiral centers are introduced through asymmetric Michael and aza-Michael reactions with excellent diastereoselectivity. 相似文献
76.
Computational protein design (CPD) aims at predicting new proteins or modifying existing ones. The computational challenge is huge as it requires exploring an enormous sequence and conformation space. The difficulty can be reduced by considering a fixed backbone and a discrete set of sidechain conformations. Another common strategy consists in precalculating a pairwise energy matrix, from which the energy of any sequence/conformation can be quickly obtained. In this work, we examine the pairwise decomposition of protein MMGBSA energy functions from a general theoretical perspective, and an implementation proposed earlier for CPD. It includes a Generalized Born term, whose many‐body character is overcome using an effective dielectric environment, and a Surface Area term, for which we present an improved pairwise decomposition. A detailed evaluation of the error introduced by the decomposition on the different energy components is performed. We show that the error remains reasonable, compared to other uncertainties. © 2014 Wiley Periodicals, Inc. 相似文献
77.
78.
Binding free energies were calculated for the inhibitors lopinavir, ritonavir, saquinavir, indinavir, amprenavir, and nelfinavir bound to HIV-1 protease. An MMPB/SA-type analysis was applied to conformational samples from 3 ns explicit solvent molecular dynamics simulations of the enzyme-inhibitor complexes. Binding affinities and the sampled conformations of the inhibitor and enzyme were compared between different HIV-1 protease protonation states to find the most likely protonation state of the enzyme in the complex with each of the inhibitors. The resulting set of protonation states leads to good agreement between calculated and experimental binding affinities. Results from the MMPB/SA analysis are compared with an explicit/implicit hybrid scheme and with MMGB/SA methods. It is found that the inclusion of explicit water molecules may offer a slight advantage in reproducing absolute binding free energies while the use of the Generalized Born approximation significantly affects the accuracy of the calculated binding affinities. 相似文献
79.
For the purpose of exploring and modeling the relationships between a dataset Y and several datasets () measured on the same individuals, multiblock Partial Least Squares is a regression technique which is widely used, particularly in process monitoring, chemometrics and sensometrics. In the same vein, a new multiblock method, called multiblock Redundancy Analysis, is proposed. It is introduced by maximizing a criterion that reflects the objectives to be addressed. The solution of this maximization problem is directly derived from the eigenanalysis of a matrix. In addition, this method is related to other multiblock methods. Multiblock modeling methods provide to the user a large spectrum of interpretation indices for the investigation of the relationships among variables and among datasets. They are related to the criterion to maximize and therefore directly derived from the maximization problem under consideration. The interest of multiblock Redundancy Analysis and the associated interpretation tools are illustrated using a dataset in the field of veterinary epidemiology. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
80.
An inorganic-organic hybrid thioantimonate(Ⅲ) [CH3(CH2)3NH3]2Sb4S7 1 with layered structure was synthesized by solvothermal method.1 crystallizes in the triclinic system, space group P with a = 7.0124(11), b = 11.919(2), c = 14.879(3) (A), α = 108.791(3), β = 102.441(3), γ = 92.846(2)o, V = 1140.1(3) (A)3, Mr = 859.71, Z = 2, Dc = 2.504 g/cm3, μ= 5.324 mm-1, F(000) = 804, S = 1.013, the final R = 0.0297 and wR = 0.0618 for 3534 observed reflections with I>2σ(I). 1 consists of [C4H9NH3] cations and two-dimensional [Sb4S7]n2n-anion which is composed of three SbS3 trigonal pyramids and one SbS4 unit joined by sharing common corners. The anionic layers are stacked perpendicularly to the c axis of the unit cell forming two-dimensional channels between the layers. The [C4H9NH3] cations interdigitate in a bilayer and reside in the 2D channels leading to a sandwich-like arrangement of the anion and cations. 相似文献