全文获取类型
收费全文 | 67篇 |
免费 | 1篇 |
国内免费 | 2篇 |
专业分类
化学 | 19篇 |
力学 | 2篇 |
数学 | 22篇 |
物理学 | 27篇 |
出版年
2018年 | 1篇 |
2017年 | 1篇 |
2015年 | 1篇 |
2014年 | 1篇 |
2013年 | 21篇 |
2012年 | 4篇 |
2011年 | 2篇 |
2009年 | 2篇 |
2005年 | 1篇 |
2004年 | 1篇 |
2002年 | 1篇 |
2000年 | 2篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1975年 | 1篇 |
1973年 | 3篇 |
1972年 | 2篇 |
1970年 | 2篇 |
1969年 | 1篇 |
1963年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有70条查询结果,搜索用时 15 毫秒
1.
PAUL SOBAJE 《Transformation Groups》2015,20(4):1141-1153
2.
In this paper we prequantize the moduli space of non-abelian vortices. We explicitly calculate the symplectic form arising
from L
2 metric and we construct a prequantum line bundle whose curvature is proportional to this symplectic form. The prequantum
line bundle turns out to be Quillen’s determinant line bundle with a modified Quillen metric. Next, as in the case of abelian
vortices, we construct line bundles over the moduli space whose curvatures form a family of symplectic forms which are parametrized
by Ψ0, a section of a certain bundle. The equivalence of these prequantum bundles are discussed. 相似文献
3.
Recent interest in higher-dimensional cosmological models has prompted some significant work on the mathematical technicalities
of how one goes about embedding spacetimes into some higher-dimensional space. We survey results in the literature (existence
theorems and simple explicit embeddings); briefly outline our work on global embeddings as well as explicit results for more
complex geometries; and provide some examples. These results are contextualized physically, so as to provide a foundation
for a detailed commentary on several key issues in the field such as: the meaning of ‘Ricci equivalent’ embeddings; the uniqueness
of local (or global) embeddings; symmetry inheritance properties; and astrophysical constraints. 相似文献
4.
An analysis is performed to study the unsteady, incompressible, one-dimensional, free convective flow over an infinite moving vertical cylinder under combined buoyancy effects of heat and mass transfer with thermal and mass stratifications. Laplace transform technique is adopted for finding solutions for velocity, temperature and concentration with unit Prandtl and Schmidt numbers. Solutions of unsteady state for larger times are compared with the solutions of steady state. Velocity, temperature and concentration profiles are analysed for various sets of physical parameters. Skin friction, Nusselt number and Sherwood number are shown graphically. It has been found that the thermal as well as mass stratification affects the flow appreciably. 相似文献
5.
Monotone interpolation of order 3 by C2 cubic splines 总被引:2,自引:0,他引:2
We propose a local solution for the problem of interpolatingmonotone data by monotone C2 cubic splines with two additionalknots per interval, on an arbitrary partition, and with an approximationof order 3. Our paper extends recent works by Archer & LeGruyer and Pruess. 相似文献
6.
VIVIENNE E. REEVE GAVIN E. GREENOAK PAUL J. CANFIELD CHRISTA BOEHM-WILCOX CLIFFORD H. GALLAGHER 《Photochemistry and photobiology》1989,49(4):459-464
Epidermal urocanic acid has been postulated to be the mediator of the specific state of immunosuppression induced by UV irradiation, by which UV-initiated tumour cells are able to evade normal recognition and can survive to grow progressively into malignant tumours. These experiments demonstrate that topical application of UV-irradiated urocanic acid systemically suppresses the contact type hypersensitivity response to oxazolone in hairless mice. In addition, topically applied urocanic acid markedly increases the overt tumour yield and the degree of malignancy in hairless mice exposed chronically to daily minimally erythemal doses of simulated solar UV light. Topical urocanic acid also increases the number of latent UV-initiated tumours, detectable by croton oil promotion. Therefore UV photoproducts of urocanic acid can both systemically suppress contact hypersensitivity in the epidermis, and also enhance early survival of UV-initiated tumour cells resulting in augmentation of UV photocarcinogenesis. 相似文献
7.
SERGE PLAZA ANNIE BOULLARD DOMINIQUE PELÉ JAN J. CORNELIS JEAN ROMMELAERE PAOLO U. GIACOMONI MICHEL PRUNIERAS 《Photochemistry and photobiology》1991,53(2):217-227
We have addressed the question whether the level of UV-B induced DNA damage can be accurately assessed by the measurement of the rate of unscheduled DNA synthesis (UDS). Cultured human fibroblasts were irradiated with UV radiation at 290, 313 or 365 nm. The LD50 was 85 J/m2 at 290 nm, 4500 J/m2 at 313 nm, and 70 kJ/m2 at 365 nm. The analysis of UDS measurements indicate complete arrest of repair processes within 24 h after irradiation, irrespective of the dose (in the range 10-60 J/m2 at 290 nm, and 250-1000 J/m2 at 313 nm). Irradiation at 365 nm failed to yield detectable evidence of UDS. Incubation of irradiated cells with an antiserum directed against both 6-4 type and cyclobutane-type pyrimidine dimers shows a clear parallelism between the disappearance of the antibody-binding determinants and the variation of the rate of UDS vs time after the end of the irradiation. Thus it is concluded that in UV-B irradiated normal cultured human fibroblasts, the lack of UDS reflects the absence of immunodetectable pyrimidine dimers. 相似文献
8.
RADIATIVE AND NON-RADIATIVE LOSSES IN THE RETINOL POLYENES 总被引:2,自引:0,他引:2
Abstract— The radiative fluorescence lifetimes of the all-trans, 9 cis and 13 cis retinol, have been measured at various temperatures, and in various solvents. The comparison of these results and of the data calculated from the absorption spectra using the Strickler and Berg equation shows that the transition probabilities are at least one hundred times lower for the radiative emission than for the absorption. Such a discrepancy, which is a general property of the polyenic structure, is closely related to the magnitude of the shift between absorption and fluorescence spectra. We interpret the observed elongation of the radiative fluorescence lifetimes and the temperature dependence of the radiative transitions in the case of all trans retinol as being due to the fact that only the lowest vibrorotational sublevels of 1 S1 , have a reasonable radiative transition probability: the temperature dependence of the radiationless transitions is considered to be due to the existence of a non radiative decay pathway at 550cal/mole above the '0' level. 相似文献
9.
10.
A DUAL-BEAM SOURCE OF ACTINIC LIGHT FOR PHOTOSYNTHESIS RESEARCH 总被引:1,自引:0,他引:1
ANGELO PAUL MARGOZZI MILTON HENDERSON ELLEN C. WEAVER 《Photochemistry and photobiology》1969,9(6):549-553
Abstract— A dual-beam source for providing illumination of white or nearly monochromatic light for photosynthesis studies is presented. The device provides programmed, repetitive sample illumination with variable intensity, pulse duration and sequence and a means of monitoring that program. It utilizes a lamp with an integral heat rejecting reflector, and a fiber optic bundle which efficiently transmits the light, diffusely and evenly illuminating the sample. 相似文献