全文获取类型
收费全文 | 91篇 |
免费 | 0篇 |
国内免费 | 2篇 |
专业分类
化学 | 19篇 |
数学 | 13篇 |
物理学 | 61篇 |
出版年
2022年 | 1篇 |
2018年 | 1篇 |
2015年 | 1篇 |
2014年 | 2篇 |
2013年 | 8篇 |
2011年 | 8篇 |
2010年 | 1篇 |
2009年 | 3篇 |
2008年 | 3篇 |
2007年 | 1篇 |
2006年 | 3篇 |
2005年 | 2篇 |
2002年 | 5篇 |
2001年 | 1篇 |
2000年 | 2篇 |
1999年 | 4篇 |
1997年 | 3篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 5篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 3篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 2篇 |
1972年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有93条查询结果,搜索用时 15 毫秒
81.
We calculate the dynamic local susceptibility () of an Ising spin glass near the de Almeida-Thouless (AT) line within the soft spin dynamics for the Sherrington-Kirkpatrick model. We find a crossover from analytic behaviour of () at =0 above the AT line to a power law behaviour ()(–i)
v
on the AT line and discuss the analytic properties of the crossover function. The frequencyscale is proportional to
1/v
, where measures the distance from the AT line. We determine the spectrum of relaxation times which diverge as
1–1/v
. The average relaxation time diverges as
–1/v
wherev1/2. In addition we determine the absolute frequency scale and prove the consistency of the ansatz of Sompolinsky and Zippelius ()–(0)(–i)
v
at and below the AT line. 相似文献
82.
Sommers HJ 《Physical review letters》1987,58(12):1268-1271
83.
The syn-carbometalation/syn-elimination of propargyl substrates to form allenes has been achieved using cationic chromium(III) catalysts activated by alkylaluminums. The mechanism and scope of this transformation are presented. 相似文献
84.
Huang J Sommers EM Kim-Shapiro DB King SB 《Journal of the American Chemical Society》2002,124(13):3473-3480
Hydroxyurea represents an approved treatment for sickle cell anemia and a number of cancers. Chemiluminescence and electron paramagnetic resonance spectroscopic studies show horseradish peroxidase catalyzes the formation of nitric oxide from hydroxyurea in the presence of hydrogen peroxide. Gas chromatographic headspace analysis and infrared spectroscopy also reveal the production of nitrous oxide in this reaction, which provides evidence for nitroxyl, the one-electron reduced form of nitric oxide. These reactions also generate carbon dioxide, ammonia, nitrite, and nitrate. None of these products form within 1 h in the absence of hydrogen peroxide or horseradish peroxidase. Electron paramagnetic resonance spectroscopy and trapping studies show the intermediacy of a nitroxide radical and a C-nitroso species during this reaction. Absorption spectroscopy indicates that both compounds I and II of horseradish peroxidase act as one-electron oxidants of hydroxyurea. Nitroxyl, generated from Angeli's salt, reacts with ferric horseradish peroxidase to produce a ferrous horseradish peroxidase-nitric oxide complex. Electron paramagnetic resonance experiments with a nitric oxide specific trap reveal that horseradish peroxidase is capable of oxidizing nitroxyl to nitric oxide. A mechanistic model that includes the observed nitroxide radical and C-nitroso compound intermediates has been forwarded to explain the observed product distribution. These studies suggest that direct nitric oxide producing reactions of hydroxyurea and peroxidases may contribute to the overall pharmacological properties of this drug. 相似文献
85.
86.
E. Sommers 《Proceedings of the American Mathematical Society》1997,125(8):2481-2484
We show that the homology of the space of Iwahori subalgebras containing a nilpotent element of a split semisimple Lie algebra over is isomorphic to the homology of the entire affine flag manifold.
87.
Paul Sommers 《General Relativity and Gravitation》1977,8(10):855-863
The members of one explicit class of functions in 2 are identified with the geodetic shear-free null congruences in Minkowski's space-time. Members of a second explicit class are identified with the type-N vacuum space-times with twist-free rays. These two classes are special subclasses from a larger class of functions associated with the type-N space-times. This larger class is characterized in the following way: If and are holomorphic variables in 2, thenu (, ,
), a function holomorphic in, belongs to the class provided the function
u/
u satisfies the tangential Cauchy-Riemann equation for an antiholomorphic function on the 3-surface whereu (, ,
) has real values.This work was supported in part by NSF grant No. MPS74-14191-A01. 相似文献
88.
James Sommers Daniel Cummings Jeffrey Giglio Kevin Carney 《Journal of Radioanalytical and Nuclear Chemistry》2009,282(2):591-595
A gas pressurized extraction chromatography (GPEC) system has been developed to perform elemental separations on radioactive
samples to determine total and isotopic compositions of Cs and Ba from an irradiated salt sample, fuel sample and two sealed
radiation sources. The GPEC system employs compressed nitrogen to move liquid through the system, compared to gravity or pumped
liquids that are typically used for separations. A commercially available Sr-Resin™ was used to perform the separation for
the above mentioned analytes. A 1% acetic acid solution was determined to be the best extractant for Ba. A flow rate of 0.1 mL/min
was determined to be optimal for the separation of Ba. Complete recovery of the Cs and Ba was achieved, within the systematic
uncertainties of the experiments. 相似文献
89.
The probability distribution of the proper delay times during scattering on a chaotic system is derived in the framework of the random matrix approach and the supersymmetry method. The result obtained is valid for an arbitrary number of scattering channels as well as arbitrary coupling to the energy continuum. The case of statistically equivalent channels is studied in detail. In particular, the semiclassical limit of an infinite number of weak channels is paid appreciable attention. 相似文献
90.
For Einstein-Maxwell fields for which the Weyl spinor is of type {2, 2}, and the electromagnetic field spinor is of type {1, 1} with its principal null directions coaligned with those of the Weyl spinor, the integrability conditions for the existence of a certain valence two Killing tensor are shown to reduce to a simple criterion involving the ratio of the amplitude of the Weyl spinor to the amplitude of a certain test solution of the spin two zero restmass field equations. The charged Kerr solution provides an example of a spacetime for which the criterion is satisfied; the chargedC-metric provides an example for which it is not.This piece of work was completed, in part, during the authors' summer 1972 stays at The University of Texas at Dallas, Division of Mathematics and Mathematical Physics, the Max-Planck-Institut für Physik und Astrophysik in München, and the Black Hole session of the Ecole d'été de Physique Théorique in Les Houches; supported, in part, by the National Science Foundation, Grants GP-8868, GP-3463 9X, GP-20023, and GU-1598; the Air Force Office of Scientific Research, Grant 903-67; the National Aeronautics and Space Administration, Grant 44-004-001; the Westinghouse Corporation; the Clark Foundation; and the Rhodes Trust. 相似文献