全文获取类型
收费全文 | 240篇 |
免费 | 8篇 |
专业分类
化学 | 112篇 |
晶体学 | 2篇 |
力学 | 5篇 |
数学 | 39篇 |
物理学 | 90篇 |
出版年
2023年 | 1篇 |
2022年 | 2篇 |
2021年 | 4篇 |
2020年 | 4篇 |
2019年 | 4篇 |
2018年 | 8篇 |
2017年 | 5篇 |
2016年 | 14篇 |
2015年 | 9篇 |
2014年 | 7篇 |
2013年 | 13篇 |
2012年 | 12篇 |
2011年 | 14篇 |
2010年 | 8篇 |
2009年 | 10篇 |
2008年 | 19篇 |
2007年 | 14篇 |
2006年 | 12篇 |
2005年 | 12篇 |
2004年 | 7篇 |
2003年 | 5篇 |
2002年 | 12篇 |
2001年 | 2篇 |
2000年 | 8篇 |
1999年 | 5篇 |
1998年 | 7篇 |
1997年 | 4篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1993年 | 1篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1985年 | 2篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1978年 | 1篇 |
排序方式: 共有248条查询结果,搜索用时 328 毫秒
41.
Davide Masoero Andrea Raimondo Daniele Valeri 《Communications in Mathematical Physics》2016,344(3):719-750
We study the ODE/IM correspondence for ODE associated to \({\widehat{\mathfrak{g}}}\)-valued connections, for a simply-laced Lie algebra \({\mathfrak{g}}\). We prove that subdominant solutions to the ODE defined in different fundamental representations satisfy a set of quadratic equations called \({\Psi}\)-system. This allows us to show that the generalized spectral determinants satisfy the Bethe Ansatz equations. 相似文献
42.
Alberto De Sole Victor G. Kac Daniele Valeri 《Communications in Mathematical Physics》2016,347(2):449-488
We develop a new method for constructing integrable Hamiltonian hierarchies of Lax type equations, which combines the fractional powers technique of Gelfand and Dickey, and the classical Hamiltonian reduction technique of Drinfeld and Sokolov. The method is based on the notion of an Adler type matrix pseudodifferential operator and the notion of a generalized quasideterminant. We also introduce the notion of a dispersionless Adler type series, which is applied to the study of dispersionless Hamiltonian equations. Non-commutative Hamiltonian equations are discussed in this framework as well. 相似文献
43.
Kazakov DV Kazakov VP Maistrenko GY Mal'zev DV Schmidt R 《The journal of physical chemistry. A》2007,111(20):4267-4273
The acetone-catalyzed decomposition of monoperoxysulfate ions, the molybdate ion-induced decay of hydrogen peroxide, and the reactions of N-chlorosuccinimide or N-bromosuccinimide with hydrogen peroxide and of dimethyldioxirane with tertiary amines as well as the thermal decomposition of 1,4-dimethylnaphthalene endoperoxide lead to the chemiluminescence of singlet-oxygen dimol species (1O2)2 emitting at 634 and 703 nm. In contrast to the expected enhancement of (1O2)2 chemiluminescence upon addition of 1,4-diazabicyclo[2.2.2]octane (DABCO) [Deneke, C.F.; Krinsky, N. I. J. Am. Chem. Soc. 1976, 98, 3041. Di Mascio, P.; Sies, H. J. Am. Chem. Soc. 1989, 111, 2909.], quenching has been observed. Our data show that enhancement of singlet-oxygen dimol chemiluminescence is not a general phenomenon and, consequently, DABCO is not a reliable chemiluminescent probe for the presence of (1O2)2 in chemical and biochemical systems. 相似文献
44.
Room temperature (RT) adsorption of oxygen on the (001) surface of metastable, cubic Co film epitaxially grown on a Fe substrate results in the formation of about 7 monolayers (ML) crystalline CoO film, in the typical rocksalt structure 45° rotated with respect to the square unit mesh of the underlying Co film. We investigated the stability of this oxide layer upon annealing in the RT–620 K temperature range, by means of primary-beam diffraction modulated electron emission (PDMEE), and X-ray photoelectron spectroscopy (XPS). For temperatures up to 570 K, film thickness and local order are preserved, in spite of an increasing number of Co and O atoms bonded in sites of reduced coordination. For larger temperatures, thickness also reduces, but the oxide film is still characterized by a high degree of CoO-like local order. 相似文献
45.
Vladimir V. Gubernov Valeri I. Babushok Sergei S. Minaev 《Combustion Theory and Modelling》2019,23(2):261-278
In this work, we introduce a global kinetic model that includes fuel, oxygen, products and two radical species involved in the reversible chain-branching, chain-propagation and chain-termination reactions. The model naturally extends the Zeldovich–Liñán and Zeldovich–Barenblatt–Dold models and can be used to describe both premixed and diffusion flames. Here it is applied to the problem of the deflagration wave propagation in the hydrocarbon fuel/air mixture with arbitrary equivalence ratio under the simplifying thermal-diffusive approximation. The conservation equations are solved numerically in order to obtain the velocity and structure of the combustion wave. It is demonstrated that the peak values of the adiabatic flame temperature and deflagration velocity are shifted towards the rich mixture composition if the reverse reactions of product decomposition are taken into account. The dependence of the flame speed and temperature on parameters of the system is analysed. The prospects of further investigation are discussed. 相似文献
46.
47.
This paper introduces a real-time optimization model that can be used by maintenance managers to develop and evaluate alternative resources allocation plans for winter road maintenance operations. The model takes into account a wide range of road and weather condition factors such as road network topology, road class, weather forecasts, and contractual service levels, and produces a vehicle dispatch schedule that is optimal with respect to operating costs and quality of service. The model is then used in an analysis on a realistic case to illustrate the potential impact of improved information on winter maintenance operations. 相似文献
48.
Nikolay S. Belyakov Valeri I. Babushok Sergei S. Minaev 《Combustion Theory and Modelling》2018,22(2):394-409
The combustion of premixed gas mixtures containing micro droplets of water was studied using one-dimensional approximation. The dependencies of the burning velocity and flammability limits on the initial conditions and on the properties of liquid droplets were analyzed. Effects of droplet size and concentration of added liquid were studied. It was demonstrated that the droplets with smaller diameters are more effective in reducing the flame velocity. For droplets vaporizing in the reaction zone, the burning velocity is independent of droplet size, and it depends only on the concentration of added liquid. With further increase of the droplet diameter the droplets are passing through the reaction zone with completion of vaporization in the combustion products. It was demonstrated that for droplets above a certain size there are two stable stationary modes of flame propagation with transition of hysteresis type. The critical conditions of the transition are due to the appearance of the temperature maximum at the flame front and the temperature gradient with heat losses from the reaction zone to the products, as a result of droplet vaporization passing through the reaction zone. The critical conditions are similar to the critical conditions of the classical flammability limits of flame with the thermal mechanism of flame propagation. The maximum decrease in the burning velocity and decrease in the combustion temperature at the critical turning point corresponds to predictions of the classical theories of flammability limits of Zel'dovich and Spalding. The stability analysis of stationary modes of flame propagation in the presence of water mist showed the lack of oscillatory processes in the frames of the assumed model. 相似文献
49.
Yael Pascal‐Levy Evgeny Shifman Dr. Manish Pal‐Chowdhury Eitan M. Hajaj Oleg Shtempluck Alexey Razin Valeri Kochetkov Prof. Yuval E. Yaish 《Chemphyschem》2012,13(18):4202-4206
Humidity plays an important role in molecular electronics. It facilitates charge movement on top of dielectric layers and modifies the device transfer characteristics. Using two different methods to probe temporal charge redistribution on the surface of dielectrics, we were able to extract the surface humidity for the first time. The first method is based on the relaxation time constants of the current through carbon nanotube field‐effect transistors (CNTFETs), and the second is based on electric force microscopy (EFM) measurements. Moreover, we found that applying external gate biases modifies the surface humidity. A theoretical model based on dielectrophoretic attraction between the water molecules and the substrate is introduced to explain this observation, and the results support our hypothesis. Furthermore, it is found that upon the adsorption of two to three layers of water the surface conductivity saturates. 相似文献
50.
L Yang S Shan R Loukrakpam V Petkov Y Ren BN Wanjala MH Engelhard J Luo J Yin Y Chen CJ Zhong 《Journal of the American Chemical Society》2012,134(36):15048-15060
The understanding of the atomic-scale structural and chemical ordering in supported nanosized alloy particles is fundamental for achieving active catalysts by design. This report shows how such knowledge can be obtained by a combination of techniques including X-ray photoelectron spectroscopy and synchrotron radiation based X-ray fine structure absorption spectroscopy and high-energy X-ray diffraction coupled to atomic pair distribution function analysis, and how the support-nanoalloy interaction influences the catalytic activity of ternary nanoalloy (platinum-nickel-cobalt) particles on three different supports: carbon, silica, and titania. The reaction of carbon monoxide with oxygen is employed as a probe to the catalytic activity. The thermochemical processing of this ternary composition, in combination with the different support materials, is demonstrated to be capable of fine-tuning the catalytic activity and stability. The support-nanoalloy interaction is shown to influence structural and chemical ordering in the nanoparticles, leading to support-tunable active sites on the nanoalloys for oxygen activation in the catalytic oxidation of carbon monoxide. A nickel/cobalt-tuned catalytic site on the surface of nanoalloy is revealed for oxygen activation, which differs from the traditional oxygen-activation sites known for oxide-supported noble metal catalysts. The discovery of such support-nanoalloy interaction-enabled oxygen-activation sites introduces a very promising strategy for designing active catalysts in heterogeneous catalysis. 相似文献