全文获取类型
收费全文 | 71篇 |
免费 | 0篇 |
专业分类
化学 | 39篇 |
晶体学 | 1篇 |
力学 | 3篇 |
数学 | 4篇 |
物理学 | 24篇 |
出版年
2021年 | 1篇 |
2020年 | 1篇 |
2017年 | 3篇 |
2016年 | 3篇 |
2015年 | 1篇 |
2012年 | 4篇 |
2011年 | 1篇 |
2008年 | 4篇 |
2007年 | 2篇 |
2006年 | 1篇 |
2005年 | 6篇 |
2004年 | 2篇 |
2003年 | 6篇 |
2002年 | 1篇 |
2001年 | 3篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1977年 | 2篇 |
1976年 | 4篇 |
1974年 | 3篇 |
1973年 | 1篇 |
1958年 | 1篇 |
1928年 | 1篇 |
排序方式: 共有71条查询结果,搜索用时 0 毫秒
1.
2.
3.
4.
We describe a technique to enhance both the weak-signal relative sensitivity and the dynamic range of a laser scanning optical microscope. The technique is based on maintaining a fixed detection power by fast feedback control of the illumination power, thereby transferring high measurement resolution to weak signals while virtually eliminating the possibility of image saturation. We analyze and demonstrate the benefits of adaptive illumination in two-photon fluorescence microscopy. 相似文献
5.
Hydrogen-bond-mediated complexation of a CG base pair by a hexylureido phthalimide and a hexylureido isoindolin-1-one was studied by (1)H NMR spectroscopy in an organic solvent. Chemical shift data indicate that both receptors effectively bind the CG base pair from the major groove side. 相似文献
6.
We quantify and ascertain the nature of the second-harmonic generation (SHG) response of amphiphilic push-pull chromophores to a transmembrane electric field. Our technique is based on the application of an alternating field across labeled giant unilamelar vesicles. For chromophore responses that are purely electro-optic, our technique provides an estimate of photoinduced charge shifts based on the observed dispersion of the field response, in accord with a two-level perturbation theory. These results are applicable to the optimization of membrane potential sensors for SHG microscopy. 相似文献
7.
Reynaud F Mertz D Celestini F Debierre JM Ghorayeb AM Simon P Stepanov A Voiron J Delmas C 《Physical review letters》2001,86(16):3638-3641
We report on the ESR, magnetization, and magnetic susceptibility measurements performed over a large temperature range, from 1.5 to 750 K, on high-quality stoichiometric LiNiO2. We find that this compound displays two distinct temperature regions where its magnetic behavior is anomalous. With the help of a statistical model based on the Kugel'-Khomskii Hamiltonian, we show that below T(of) approximately 400 K, an orbitally frustrated state characteristic of the triangular lattice is established. This then gives a solution to the long-standing controversial problem of the magnetic behavior in LiNiO2. 相似文献
8.
Membrane imaging by simultaneous second-harmonic generation and two-photon microscopy 总被引:5,自引:0,他引:5
We demonstrate that simultaneous second-harmonic generation (SHG) and two-photon-excited fluorescence (TPEF) can be used to rapidly image biological membranes labeled with a styryl dye. The SHG power is made compatible with the TPEF power by use of near-resonance excitation, in accord with a model based on the theory of phased-array antennas, which shows that the SHG radiation is highly structured. Because of its sensitivity to local asymmetry, SHG microscopy promises to be a powerful tool for the study of membrane dynamics. 相似文献
9.
In an earlier work made by the first author with J. Turi (Degenerate Dirichlet Problems Related to the Invariant Measure of Elasto-Plastic Oscillators, AMO, 2008), the solution of a stochastic variational inequality modeling an elasto-perfectly-plastic oscillator has been studied. The existence and uniqueness of an invariant measure have been proven. Nonlocal problems have been introduced in this context. In this work, we present a new characterization of the invariant measure. The key finding is the connection between nonlocal PDEs and local PDEs which can be interpreted with short cycles of the Markov process solution of the stochastic variational inequality. 相似文献
10.
K. Mertz F. Zettler H.D. Hausen J. Weidlein 《Journal of organometallic chemistry》1976,122(2):159-170
Dimethyl(cyclopentadienyl gallium, (CH3)2GaC5H5, crystallizes with monoclinic symmetry in space group P21/c; the cell dimensions are a = 6.587(3), b = 9.154(3), c = 12.756(5) Å and β = 113.20(3)o with Z = 4. The structure was solved using heavy atom techniques and refined by least-squares techniques to give a value of R = 0.046 for the 1719 observed reflections. The structure consists of chains of dimethylgallium-groups bridged by cyclopentadienyl rings along the b-axis. Each gallium atom has a distorted tetrahedral environment with Ga-methyl distances of 1.965 Å and Ga-Cp distances of 2.215 and 2.314 Å, respectively. 相似文献