全文获取类型
收费全文 | 2108篇 |
免费 | 88篇 |
国内免费 | 3篇 |
专业分类
化学 | 1742篇 |
晶体学 | 12篇 |
力学 | 17篇 |
数学 | 159篇 |
物理学 | 269篇 |
出版年
2023年 | 26篇 |
2022年 | 65篇 |
2021年 | 117篇 |
2020年 | 71篇 |
2019年 | 69篇 |
2018年 | 78篇 |
2017年 | 47篇 |
2016年 | 114篇 |
2015年 | 57篇 |
2014年 | 92篇 |
2013年 | 134篇 |
2012年 | 127篇 |
2011年 | 150篇 |
2010年 | 97篇 |
2009年 | 87篇 |
2008年 | 136篇 |
2007年 | 105篇 |
2006年 | 108篇 |
2005年 | 88篇 |
2004年 | 77篇 |
2003年 | 60篇 |
2002年 | 51篇 |
2001年 | 34篇 |
2000年 | 9篇 |
1999年 | 17篇 |
1998年 | 12篇 |
1997年 | 12篇 |
1996年 | 20篇 |
1995年 | 5篇 |
1994年 | 6篇 |
1993年 | 4篇 |
1992年 | 6篇 |
1991年 | 7篇 |
1990年 | 9篇 |
1988年 | 5篇 |
1987年 | 4篇 |
1986年 | 6篇 |
1985年 | 6篇 |
1984年 | 5篇 |
1982年 | 5篇 |
1981年 | 6篇 |
1980年 | 7篇 |
1978年 | 5篇 |
1976年 | 5篇 |
1975年 | 4篇 |
1973年 | 5篇 |
1971年 | 4篇 |
1967年 | 3篇 |
1966年 | 3篇 |
1963年 | 3篇 |
排序方式: 共有2199条查询结果,搜索用时 15 毫秒
1.
General Relativity and Gravitation - In previous work, we established theoretical results concerning the effect of matter shells surrounding a gravitational wave (GW) source, and we now apply these... 相似文献
2.
Prof. Dr. Francisco Melo Leonardo Caballero Esteban Zamorano Natalia Ventura Camilo Navarro Irving Doll Prof. Dr. Pedro Zamorano Prof. Dr. Alberto Cornejo 《Chemphyschem》2021,22(6):526-532
Parkinson's disease is a neurodegenerative disorder involving a functional protein, α-synuclein, whose primary function is related to vesicle trafficking. However, α-synuclein is prone to form aggregates, and these inclusions, known as Lewy bodies, are the hallmark of Parkinson's disease. α-synuclein can alter its conformation and acquire aggregating capacity, forming aggregates containing β-sheets. This protein's pathogenic importance is based on its ability to form oligomers that impair synaptic transmission and neuronal function by increasing membrane permeability and altering homeostasis, generating a deleterious effect over cells. First, we establish that oligomers interfere with the mechanical properties of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) membrane, as demonstrated by nanoindentation curves. In contrast, nanoindentation revealed that the α-synuclein monomer's presence leads to a much more resistant lipid bilayer. Moreover, the oligomers’ interaction with cell membranes can promote lactate dehydrogenase (LDH) release, suggesting the activation of cytotoxic events. 相似文献
3.
4.
Natalia L. Calvo Sebastian O. SimonettiRubén M. Maggio Teodoro S. Kaufman 《Analytica chimica acta》2015
Exposure of cimetidine (CIM) to dry heat (160–180 °C) afforded, upon cooling, a glassy solid containing new and hitherto unknown products. The kinetics of this process was studied by a second order chemometrics-assisted multi-spectroscopic approach. Proton and carbon-13 nuclear magnetic resonance (NMR), as well as ultraviolet and infrared spectroscopic data were jointly used, whereas multivariate curve resolution with alternating least squares (MCR-ALS) was employed as the chemometrics method to extract process information. It was established that drug degradation follows a first order kinetics. 相似文献
5.
Formalization for problems of multicriteria decision making under uncertainty is constructed in terms of guaranteed and weak
estimates. A relevant definition of the vector maximinimax value is given. Parameterization and approximation of maximum,
minimax, and maximinimax values based on the inverse logical convolution are suggested. An application for multicommodity
networks is considered.
Received: December 13, 2000 / Accepted: August 21, 2001?Published online May 8, 2002 相似文献
6.
Kurenkov V. F. Zaitseva O. A. Kirdyashova G. N. 《Russian Journal of Applied Chemistry》2002,75(4):641-644
The kinetics of radical copolymerization of acrylamide with lithium, sodium, and potassium 2-acrylamido-2-methylpropanesulfonates in concentrated aqueous solutions in the presence of potassium persulfate as initiating agent at pH 9 and 50°C was studied by dilatometry. 相似文献
7.
We obtain expressions for the energy spectrum widths of Rayleigh waves corresponding to their deformational coupling to Fermi and Boltzmann electrons in a two-dimensional layer near the surface of a semibounded solid. We evaluate the nonequilibrium energy of Rayleigh waves that depends on these widths and is caused by the same coupling to the corresponding hot electrons. We show that this energy is independent of the degeneracy degree of the electrons and is given by the mean energy of free Rayleigh waves heated up to temperature of the electrons. We find conditions under which the thermodynamics is determined by this nonequilibrium energy of Rayleigh waves in films of a certain thickness with Fermi electrons near the surface and by the equilibrium energy of bulk phonons in thicker samples. All the results are obtained using the Keldysh diagram technique applied to the case of semibounded media. 相似文献
8.
L. A. Zaitseva 《Theoretical and Mathematical Physics》1998,115(2):595-606
The nonequilibrium phonon energy due to deformation interactions with hot electrons is determined. This energy depends on
the lifetime of phonons with fixed momentum. Lifetime for phonons scattered by electrons and by macroscopic and microscopic
impurities are calculated using the Keldysh diagram technique.
Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 115, No. 2, pp. 289–304, May, 1998. 相似文献
9.
V. B. Kobychev N. M. Vitkovskaya I. L. Zaitseva B. A. Trofimov 《Journal of Structural Chemistry》2004,45(6):940-944
The profiles of reactions leading to pyrrole anion N-adducts with CO2 and CS2 have been studied by the ab initio (RHF/6-31+G*, MP2/6-31+G*) and density functional (B3LYP/6-31+G*) methods. Addition of the pyrrole anion to the carbon disulfide molecule is accompanied by the appearance of a minimum corresponding to a pre-reaction complex. The transformation of the complex to the N-pyrrolyldithiocarboxylate anion occurs via a low activation barrier, which is due to repolarization of the C=S bonds. The profile of the reaction leading to the pyrrole anion N-adduct with CO2 does not contain any intermediate stationary points throughout the whole route from reagents to products.Original Russian Text Copyright © 2004 by V. B. Kobychev, N. M. Vitkovskaya, I. L. Zaitseva, and B. A. Trofimov__________Translated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 6, pp. 990–993, November–December, 2004. 相似文献
10.