全文获取类型
收费全文 | 63919篇 |
免费 | 1989篇 |
国内免费 | 247篇 |
专业分类
化学 | 38389篇 |
晶体学 | 278篇 |
力学 | 1452篇 |
综合类 | 2篇 |
数学 | 11577篇 |
物理学 | 14457篇 |
出版年
2023年 | 296篇 |
2021年 | 537篇 |
2020年 | 808篇 |
2019年 | 644篇 |
2018年 | 718篇 |
2017年 | 707篇 |
2016年 | 1544篇 |
2015年 | 1408篇 |
2014年 | 1570篇 |
2013年 | 3393篇 |
2012年 | 2942篇 |
2011年 | 3568篇 |
2010年 | 1916篇 |
2009年 | 1612篇 |
2008年 | 3248篇 |
2007年 | 3195篇 |
2006年 | 3078篇 |
2005年 | 2773篇 |
2004年 | 2427篇 |
2003年 | 1959篇 |
2002年 | 1672篇 |
2001年 | 1027篇 |
2000年 | 906篇 |
1999年 | 677篇 |
1998年 | 613篇 |
1997年 | 758篇 |
1996年 | 828篇 |
1995年 | 793篇 |
1994年 | 847篇 |
1993年 | 884篇 |
1992年 | 764篇 |
1991年 | 649篇 |
1990年 | 645篇 |
1989年 | 591篇 |
1988年 | 589篇 |
1987年 | 532篇 |
1986年 | 537篇 |
1985年 | 833篇 |
1984年 | 824篇 |
1983年 | 736篇 |
1982年 | 776篇 |
1981年 | 745篇 |
1980年 | 744篇 |
1979年 | 640篇 |
1978年 | 707篇 |
1977年 | 666篇 |
1976年 | 563篇 |
1975年 | 517篇 |
1974年 | 504篇 |
1973年 | 478篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Applications of Mathematics - Proper traffic simulation of electric vehicles, which draw energy from overhead wires, requires adequate modeling of traction infrastructure. Such vehicles include... 相似文献
2.
Semigroup Forum - It is well known that the set of isomorphism classes of extensions of groups with abelian kernel is characterized by the second cohomology group. In this paper we generalise this... 相似文献
3.
Foundations of Computational Mathematics - We develop some aspects of the homological algebra of persistence modules, in both the one-parameter and multi-parameter settings, considered as either... 相似文献
4.
5.
Prof. Dr. Peter Hess 《Chemphyschem》2022,23(6):e202100880
In the periodic table the position of each atom follows the ‘aufbau’ principle of the individual electron shells. The resulting intrinsic periodicity of atomic properties determines the overall behavior of atoms in two-dimensional (2D) bonding and structure formation. Insight into the type and strength of bonding is the key in the discovery of innovative 2D materials. The primary features of 2D bonding and the ensuing monolayer structures of the main-group II–VI elements result from the number of valence electrons and the change of atom size, which determine the type of hybridization. The results reveal the tight connection between strength of bonding and bond length in 2D networks. The predictive power of the periodic table reveals general rules of bonding, the bonding-structure relationship, and allows an assessment of published data of 2D materials. 相似文献
6.
Etémé Armand Sylvin Tabi Conrad Bertand Beyala Ateba Jean Félix Ekobena Fouda Henry Paul Mohamadou Alidou Crépin Kofané Timoléon 《Nonlinear dynamics》2021,105(1):785-795
Nonlinear Dynamics - The fluctuation of ions concentration across the cell membrane of neuron can generate a time varying electromagnetic field. Thus, memristors are used to realize the coupling... 相似文献
7.
Zayed Elsayed M. E. Shohib Reham M. A. Alngar Mohamed E. M. Yıldırım Yakup 《Computational Mathematics and Modeling》2021,32(2):235-252
Computational Mathematics and Modeling - Based on the extended simplest equation method, we construct solitons and other solutions for the nonlinear convection-diffusion-reaction equation with... 相似文献
8.
Journal of Nonlinear Science - The isothermal quasistatic (i.e. acceleration neglected) hardening-free plasticity at large strains is considered, based on the standard multiplicative decomposition... 相似文献
9.
Benedikt Sapotta Matthias Schwotzer Christof Wöll Matthias Franzreb 《Electroanalysis》2022,34(3):512-522
We demonstrate a novel impedimetric approach providing unprecedented insight into characteristic properties of dielectric thin films covering electrode surfaces. The concept is based on the joint interpretation of electrochemical impedance spectroscopy (EIS) together with dielectrometry (DEM) whose informative value is mutually interconnected. The advantage lies in the synergistic compensation of individual shortcomings adversely affecting conventional impedimetric analysis strategies relying exclusively on either DEM or the traditional EIS approach, which in turn allows a reliable determination of thickness and permittivity values. The versatility of the method proposed is showcased by an in-situ growth-monitoring of a nanoporous, crystalline thin film (HKUST-1) on an interdigitated electrode geometry. 相似文献
10.
Samia Amara Joël Toulc'Hoat Laure Timperman Agnès Biller Hervé Galiano Corinne Marcel Matthieu Ledigabel Prof. Mérièm Anouti 《Chemphyschem》2019,20(4):581-594
The development of a suitable functional electrolyte is urgently required for fast-charging and high-voltage alkali-ion (Li, Na, K) batteries as well as next-generation hybrids supercapacitors. Many recent works focused on an optimal selection of electrolytes for alkali-ion based systems and their electrochemical performance but the understanding of the fundamental aspect that explains their different behaviour is rare. Herein, we report a comparative study of transport properties for LiPF6, NaPF6, KPF6 in acetonitrile (AN) and a binary mixture of ethylene carbonate (EC), dimethyl carbonate (DMC): (EC/DMC : 1/1, weigh) through conductivities, densities and viscosities measurements in wide temperature domain. By application of the Stokes-Einstein, Nernst-Einstein, and Jones Dole equations, the effective ionic solvated radius of cation (reff), the ionic dissociation coefficient (αD) and structuring Jones Dole's parameters (A, B) for salt are calculated and discussed according to solvent or cation nature as a function of temperature. From the results, we demonstrate that better mobility of potassium can be explained by the nature of the ion-ion and ion-solvent interactions due to its polarizability. In the same time, the predominance of triple ions in the case of K+, is a disadvantage at high concentration. 相似文献