全文获取类型
收费全文 | 180篇 |
免费 | 3篇 |
国内免费 | 1篇 |
专业分类
化学 | 65篇 |
力学 | 7篇 |
数学 | 17篇 |
物理学 | 95篇 |
出版年
2021年 | 2篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2016年 | 2篇 |
2015年 | 2篇 |
2014年 | 2篇 |
2013年 | 5篇 |
2012年 | 10篇 |
2011年 | 6篇 |
2010年 | 4篇 |
2008年 | 7篇 |
2007年 | 9篇 |
2006年 | 7篇 |
2005年 | 3篇 |
2004年 | 6篇 |
2003年 | 6篇 |
2002年 | 2篇 |
2001年 | 4篇 |
2000年 | 8篇 |
1999年 | 9篇 |
1998年 | 5篇 |
1997年 | 3篇 |
1996年 | 6篇 |
1995年 | 2篇 |
1993年 | 5篇 |
1992年 | 1篇 |
1991年 | 4篇 |
1990年 | 5篇 |
1989年 | 1篇 |
1988年 | 3篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1984年 | 2篇 |
1982年 | 7篇 |
1981年 | 3篇 |
1980年 | 5篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1977年 | 4篇 |
1976年 | 3篇 |
1975年 | 1篇 |
1974年 | 4篇 |
1973年 | 3篇 |
1972年 | 1篇 |
1970年 | 1篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1962年 | 1篇 |
1959年 | 1篇 |
1936年 | 1篇 |
排序方式: 共有184条查询结果,搜索用时 15 毫秒
81.
Molecular dynamics simulations of supported shock waves (shock pressure P(s) ~ 15 GPa) propagating along the [110], [011], [101], and [111] directions in crystalline nitromethane initially at T = 200 K were performed using the nonreactive Sorescu-Rice-Thompson force field [D. C. Sorescu, B. M. Rice, and D. L. Thompson, J. Phys. Chem. B 104, 8406 (2000)]. These simulations, combined with those from a preceding study of shocks propagating along [100], [010], and [001] directions in nitromethane for similar conditions of temperature and shock pressure [L. He, T. D. Sewell, and D. L. Thompson, J. Chem. Phys. 134, 124506 (2011)], have been used to study the post-shock relaxation phenomena. Shocks along [010] and [101] lead to a crystal-crystal structure transformation. Shocks propagating along [011], [110], [111], [100], and [001] exhibit plane-specific disordering, which was characterized by calculating as functions of time the 1D mean square displacement (MSD), 2D radial distribution function (RDF), and 2D orientation order parameter P(2)(θ) in orthogonal planes mutually perpendicular to the shock plane; and by calculating as functions of distance behind the shock front the Cartesian components of intermolecular, intramolecular, and total kinetic energies. The 2D RDF results show that the structural disordering for shocks along [100], [110], and [111] is strongly plane-specific; whereas for shocks along [001] and [011], the loss of crystal structural order is almost equivalent in the orthogonal planes perpendicular to the shock plane. Based on the entire set of simulations, there is a trend for the most extensive disordering to occur in the (010) and (110) planes, less extensive disordering to occur in the (100) plane, and essentially no disordering to occur in the (001) plane. The 2D P(2)(θ) and 1D MSD profiles show, respectively, that the orientational and translational disordering is plane-specific, which results in the plane-specific structural disordering observed in the 2D RDF. By contrast, the kinetic energy partitioning and redistribution do not exhibit plane specificity, as shown by the similarity of spatial profiles of the Cartesian components of the intermolecular, intramolecular, and total kinetic energies in orthogonal planes perpendicular to the shock plane. 相似文献
82.
David R. Morrison Edward C. Sewell Sheldon H. Jacobson 《European Journal of Operational Research》2014
The simple assembly line balancing problem (SALBP) is a well-studied NP-complete problem for which a new problem database of generated instances was published in 2013. This paper describes the application of a branch, bound, and remember (BB&R) algorithm using the cyclic best-first search strategy to this new database to produce provably exact solutions for 86% of the unsolved problems in this database. A new backtracking rule to save memory is employed to allow the BB&R algorithm to solve many of the largest problems in the database. 相似文献
83.
84.
Erika L. Milczek Laura Palmiero Sarah L. Sewell Kyle S. Knight 《Transition Metal Chemistry》2006,31(1):27-29
Secondary alkyl bromides were reduced by diisobutylaluminum hydride and ethylmagnesium chloride in the presence of catalysts
derived from chelating diphosphine complexes of palladium. Traditional palladium(0) diphosphine complexes generated by other
means were not viable catalysts for the reaction in the absence of diisobutylaluminum hydride and ethylmagnesium chloride.
Deuterium labeling experiments indicate that the reaction does not take place via halogen metal exchange. 相似文献
85.
86.
87.
88.
Laboratory, ground-based, and airborne tunable diode laser systems: performance characteristics and applications in atmospheric studies 总被引:4,自引:0,他引:4
A. Fried B. Henry B. Wert S. Sewell J.R. Drummond 《Applied physics. B, Lasers and optics》1998,67(3):317-330
2 O) used as the target gas. One method utilizes the Allan variance. When our present aircraft system is operated in the laboratory,
the Allan variance indicates a CH2O detection limit of 0.031 ppbv for integration times of 25 s. This sensitivity corresponds to a minimum detectable absorbance
of 1.0×10-6, and this is within a factor of two of that reported by Werle et al. who used high-frequency modulation spectroscopy. The
present instrument utilizes conventional low-frequency (2f=100 kHz) wavelength modulation. Instrument performance, obtained
from replicate measurements of CH2O standards acquired over time periods as long as 1.5 hours, on average resulted in a factor of two poorer precision than
indicated by the Allan variance. Since replicate measurements precisely simulate the acquisition procedures employed, including
the acquisition of sample and background spectra, they present a more meaningful measure of instrument performance. Preliminary
evidence suggests that slow drifts in the laser wavelength control during acquisition of replicate measurements may play an
important role in the above disparity. The resultant laser wavelength correction voltage, which is applied to counter such
drifts, may also be a factor in this disparity. A limited number of replicate measurements with minimal drift in the laser
wavelength yield much closer agreement between replicate and Allan variance precisions.
Received: 19 March 1998/Revised version: 2 June 1998 相似文献
89.
Transonic trailing-edge flow 总被引:1,自引:0,他引:1
Bodonyi RJ; Kluwick A 《The Quarterly Journal of Mechanics and Applied Mathematics》1998,51(2):297-310
90.