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141.
本文针对多因素决策问题 ,建立了一种多专家协调决策的理论、方法、计算过程和应用实例 .设计了相应的智能化计算机决策支持系统 .  相似文献   
142.
Summary Asymptotic properties of several estimators of interclass correlation from familial data are examined in the case of a variable number of siblings per family. After showing that the usual sib-mean estimator is not consistent, a modified sib-mean estimator is proposed. Asymptotic distributions of estimators are derived and a test procedure is provided for a certain testing problem concerning interclass correlation. Several estimators are compared in the various mean number of siblings per family, using asymptotic mean square errors. The Institute of Statistical Mathematics  相似文献   
143.
The Cholesky decomposition (CD) technique, used to approximate the two‐electron repulsion integrals (ERIs), is applied to the valence bond self‐consistent field (VBSCF) method. Test calculations on ethylene, C2nH2n+2, and C2nH4n?2 molecules (n = 1–7) show that the performance of the VBSCF method is much improved using the CD technique, and thus, the integral transformation from basis functions to VB orbitals is no longer the bottleneck in VBSCF calculations. The errors of the CD‐based ERIs and of the total energy are controlled by the CD threshold, for which a value of 10?6 ensures to control the total energy error within 10?6 Hartree. © 2016 Wiley Periodicals, Inc.  相似文献   
144.
We have investigated the convergence of third order correlation energy within the hierarchies of correlation consistent basis sets for helium, neon, and water, and for three stationary points of hydrogen peroxide. This analysis confirms that singlet pair energies converge much slower than triplet pair energies. In addition, singlet pair energies with (aug)-cc-pVDZ and (aug)-cc-pVTZ basis sets do not follow a converging trend and energies with three basis sets larger than aug-cc-pVTZ are generally required for reliable extrapolations of third order correlation energies, making so the explicitly correlated R12 calculations preferable.  相似文献   
145.
146.
耿美华 《数学杂志》2011,31(4):587-593
本文研究了风险偏好问题.利用简单市场模型,讨论了个人风险偏好和市场风险偏好,给出了两种风险偏好的数学定义,该定义具有自然直观的经济学意义.  相似文献   
147.
郑浩平 《物理学进展》2011,20(3):291-300
蛋白质分子电子结构的计算对生命科学和计算机药物设计有重要的科学意义和应用价值 ,但对计算方法和计算机也是巨大的挑战。团簇埋入自洽计算法是近年来发展起来的“第一性原理”、从头计算法。它采用局域化无相互作用单电子模型 ,结合“分块 合拢”技术 ,使计算量大大减少。最近 ,应用该方法 ,对一个真实蛋白质分子 (南瓜种子中的胰蛋白酶抑止因子CMTI I)电子结构的首次“第一性原理”、全电子、全势场、从头计算获得成功。表明生物大分子电子结构的计算在现有计算机条件下已成为现实 ,使从本质上揭开生命奥秘成为可能。本文介绍了上述计算的基本理论、方法和结果。  相似文献   
148.
Scale factors for (a) low (<1000 cm(-1)) and high harmonic vibrational frequencies, (b) thermal contributions to enthalpy and entropy, and (c) zero-point vibrational energies have been determined for five hybrid functionals (B3P86, B3PW91, PBE1PBE, BH&HLYP, MPW1K), five pure functionals (BLYP, BPW91, PBEPBE, HCTH93, and BP86), four hybrid meta functionals (M05, M05-2X, M06, and M06-2X) and one double-hybrid functional (B2GP-PLYP) in combination with the correlation consistent basis sets [cc-pVnZ and aug-cc-pVnZ, n = D(2),T(3),Q(4)]. Calculations for vibrational frequencies were carried out on 41 organic molecules and an additional set of 22 small molecules was used for the zero-point vibrational energy scale factors. Before scaling, approximately 25% of the calculated frequencies were within 3% of experimental frequencies. Upon application of the derived scale factors, nearly 90% of the calculated frequencies deviated less than 3% from the experimental frequencies for all of the functionals when the augmented correlation consistent basis sets were used.  相似文献   
149.
Numerical SCFT simulations of inhomogeneous polymers at the mesoscale can easily become computationally extremely demanding as the size (spatial resolution) of the simulated 3D system increases, making massively parallel computing a necessity. A new parallel algorithm for large‐scale 3D SCFT simulations of rod‐coil copolymers with interplay between microphase separation and orientational ordering is presented. For large systems, this algorithm scales well up to 1024 processors, achieving more than 200‐fold speedups. While existing SCFT simulations were limited to studying 1D and 2D models, this algorithm is applied to new, intrinsic 3D structures such as a hexagonally arranged columnar morphology that possesses macroscopic chirality arising as a result of spontaneous symmetry breaking.

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150.
任春来 《高分子科学》2012,30(2):164-172
Combining self-consistent-field theory and density-functional theory,we systematically study the deformation of copolymer micelles induced by the presence of amphiphilic dimer particles.Due to the amphiphilic nature,dimer particles tend to accumulate onto the interface of the copolymer micelle.With increasing concentration of the symmetric dimer particles,which are made of two identical spherical particles,the micelle deforms from the initial sphere to ellipse,dumbbell, and finally separates into two micelles.Furthermore,asymmetric dimer particles,composed by two particles with different sizes,are considered to investigate the influence of geometry of dimer particles on the deformation of the micelle.It is found that the micelle inclines to deform into dumbbell due to the additional curvature originating in the gathering of asymmetric dimer particles onto the interface of the micelle.The present study on the deformation of micelles is useful to understand the possible shape variation in the course of cell division/fusion.  相似文献   
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