全文获取类型
收费全文 | 199篇 |
免费 | 1篇 |
专业分类
化学 | 102篇 |
晶体学 | 1篇 |
力学 | 13篇 |
数学 | 18篇 |
物理学 | 66篇 |
出版年
2022年 | 2篇 |
2018年 | 1篇 |
2017年 | 2篇 |
2015年 | 4篇 |
2014年 | 3篇 |
2013年 | 9篇 |
2012年 | 4篇 |
2011年 | 8篇 |
2010年 | 5篇 |
2009年 | 3篇 |
2008年 | 8篇 |
2007年 | 12篇 |
2006年 | 6篇 |
2005年 | 7篇 |
2004年 | 13篇 |
2003年 | 3篇 |
2002年 | 4篇 |
2001年 | 3篇 |
2000年 | 2篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 5篇 |
1994年 | 4篇 |
1993年 | 3篇 |
1992年 | 3篇 |
1991年 | 4篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 3篇 |
1987年 | 4篇 |
1985年 | 2篇 |
1984年 | 7篇 |
1983年 | 1篇 |
1982年 | 10篇 |
1981年 | 4篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 6篇 |
1976年 | 7篇 |
1975年 | 3篇 |
1974年 | 5篇 |
1973年 | 3篇 |
1972年 | 2篇 |
1971年 | 2篇 |
1970年 | 1篇 |
1967年 | 1篇 |
1966年 | 1篇 |
1928年 | 1篇 |
排序方式: 共有200条查询结果,搜索用时 15 毫秒
81.
J.F. van der Veen D.E. Eastman A.M. Bradshaw S. Holloway 《Solid State Communications》1981,39(12):1301-1304
Using angle-resolved photoemission, we have identified a new surface state on Ir(332), which can be unambigously associated with step sites. This state is located near the Fermi level and can be distinguished from a terrace-related state by preferential adsorption of hydrogen on the rows of step atoms. Terrace and step atoms are shown to exhibit different 4f-core level binding energies, a fact which can be used to independently monitor preferential adsorption. 相似文献
82.
83.
In this short review we consider some selected results for the dissociation of hydrogen on metal surfaces. In particular we focus our attention on the effects that surface corrugation have on the dissociation and also how rotations and vibrations couple in the interaction region. Results from time dependent quantum wavepacket calculations have been particularly helpful in forming our ideas of how diatomics dissociate. We describe this method along with two examples of propagation schemes. The power of limited dimensional models to rationalize experimental observations is clearly demonstrated. 相似文献
84.
A multispecies gas described by coupled nonlinear Boltzmann equations is studied as a dynamical system. Properties are determined of theN coupled nonlinear ODEs for the number densities obtained from the Boltzmann equations for the spatially uniform system ofN species undergoing binary scattering, removal, and regeneration in the presence of an external force field and a reservoir of background gas. The physically realizable setQ, the nonnegative cone in theN-dimensional phase space of species number densities, is established as invariant under the flow. The fixed-point equations for the ODEs are shown to be equivalent to 2
N
linear systems, and conditions for the stability and instability of the fixed points are then established. Stable fixed points are demonstrated to exist inQ by showing that they enter via a sequence of transcritical bifurcations as physical parameters are varied. For the two-species case the typical global structure of the solutions is established. Various particular cases are described including one which possesses an infinite family of periodic solutions and one that depends delicately upon initial conditions due to a separatrix that separatesQ into two invariant sets. 相似文献
85.
A. Deneuville C.H. Park P. Ayyub T. Anderson P. Lowen K. Jones P.H. Holloway 《Applied Surface Science》1991,50(1-4):308-311
We probe the “bulk” and near-surface regions of O-implanted heteroepitaxial ZnSe films, using the full-width at half-maximum (FWHM) of the Raman line. The results are compared to those after N implantation. A tensile stress attributed to a deformation in the lattice around O is found. Under rapid thermal annealing, the optimum temperature for the recovery of the implantation damage without suffering from thermally generated point defects is Ta = 500°C. It corresponds here to the maximum FWHM from the uncompensated tensile stress, while identical FWHM's are found for the top and the “bulk” part of the film just after implantation, and after implantation and Ta = 600°C. 相似文献
86.
The general theory of the desorption of atoms from surfaces is discussed and a method given for the calculation of the surface residence time. Potential parameters are deduced for a number of experimental systems using a variety of adsorption sites to model the interactions. By using this technique valuable information about the surface-atom potential may be obtained. 相似文献
87.
A patented method of steam classification (the Holloway Process) and a prototype process unit have been investigated. The process treats municipal solid wastes (MSW) with steam and pressure to yield sterilized recyclable metals, glass, and plastics and a cellulosic pulp. After processing, the components of the mixture are separated into three sizes by vibratory screening. The recyclable materials must be subsequently separated from the screened fractions. Process conditions have been optimized to maximize the yield of a sterile cellulosic fraction that has a variety of possible end uses, such as compost, combustion fuel, and feedstock for conversion to fuels and chemicals. 相似文献
88.
The time-dependent, mean-field Newns-Anderson model for a spin-polarized adsorbate approaching a metallic surface is solved in the wide-band limit. Equations for the time evolution of the occupation of the spin dependent adsorbate states and for the nonadiabatic and nearly adiabatic adsorbate-surface energy transfer rates are derived. Numerical solutions are obtained using characteristic parameters derived from density functional theory calculations for the H/Cu(111) system. The time evolution of the model system is shown to be strongly nonadiabatic in the vicinity of the transition point between spin-polarized and nonpolarized ground states. Away from the spin transition the nonadiabatic energy transfer is in close agreement with the nearly adiabatic limit. Near the transition, nonadiabatic effects are large and the nearly adiabatic approximation fails. 相似文献
89.
Stuart A. Brewer Alan K. Brisdon John Fawcett Peter J. Holliman John H. Holloway Eric G. Hope David R. Russell 《无机化学与普通化学杂志》2006,632(2):325-329
The direct fluorination of intimately mixed niobium and tantalum powders gives a range of mixed‐metal pentafluorides [NbxTa4‐xF20] (x = 1 2 , 2 3 , 3 4 ) as discreet species isostructural with tantalum pentafluoride (x = 0 1 ). The crystal structures of 1–4 are indistinguishable by X‐ray crystallography. Complex 1 crystallizes in the monoclinic space group C2/m with a = 9.5462(13), b = 14.3578(19), c = 5.0174(7) Å, β = 97.086(2)°, Z = 2. The geometry about the tantalum atom is distorted octahedral with 2 short and 2 slightly longer Ta‐Fterminal, and 2 Ta‐Fbridging distances. The angles at the bridging fluorine atoms are 172.9(5)°. 相似文献
90.
Steven C. Gauci Prof. Filip E. Du Prez Dr. Joshua O. Holloway Dr. Hannes A. Houck Prof. Christopher Barner-Kowollik 《Angewandte Chemie (International ed. in English)》2023,62(40):e202310274
Exploiting the optimum wavelength of reactivity for efficient photochemical reactions has been well-established based on the development of photochemical action plots. We herein demonstrate the power of such action plots by a remarkable example of the wavelength-resolved photochemistry of two triazolinedione (TAD) substrates, i.e., aliphatic and aromatic substituted, that exhibit near identical absorption spectra yet possess vastly disparate photoreactivity. We present our findings in carefully recorded action plots, from which reaction selectivity is identified. The profound difference in photoreactivity is exploited by designing a ‘hybrid’ bisfunctional TAD molecule, enabling the formation of a dual-gated reaction manifold that demonstrates the exceptional and site-selective (photo)chemical behavior of both TAD substrates within a single small molecule. 相似文献