全文获取类型
收费全文 | 265篇 |
免费 | 1篇 |
国内免费 | 16篇 |
专业分类
化学 | 57篇 |
晶体学 | 2篇 |
力学 | 14篇 |
数学 | 1篇 |
物理学 | 208篇 |
出版年
2024年 | 1篇 |
2023年 | 5篇 |
2022年 | 2篇 |
2021年 | 5篇 |
2020年 | 7篇 |
2019年 | 2篇 |
2017年 | 6篇 |
2016年 | 8篇 |
2015年 | 4篇 |
2014年 | 6篇 |
2013年 | 7篇 |
2012年 | 7篇 |
2011年 | 10篇 |
2010年 | 12篇 |
2009年 | 23篇 |
2008年 | 10篇 |
2007年 | 36篇 |
2006年 | 29篇 |
2005年 | 2篇 |
2004年 | 10篇 |
2003年 | 35篇 |
2002年 | 21篇 |
2001年 | 30篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1995年 | 1篇 |
排序方式: 共有282条查询结果,搜索用时 15 毫秒
61.
A. Fielicke G. Meijer G. von Helden 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,24(1-3):69-72
Infrared spectra in the range of 530–1400
cm–1 are presented for tantalum oxide
cluster cations
(x = 3, 4 and 6). These spectra are
obtained via multiple photon
dissociation (MPD) spectroscopy of free cluster cations moving
in a molecular beam. The IR spectra for
are compared to spectra of
as well as to the experimental data
available for vanadium oxide cluster cations from IR-MPD
spectroscopy. For
and
the IR spectra exhibit very strong
similarities (including the band positions), whereas absorption
bands in
are relatively blue-shifted by
about 20–40 cm–1. 相似文献
62.
M. Dubiel H. Hofmeister G. L. Tan K.-D. Schicke E. Wendler 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,24(1-3):361-364
Silver particles in soda-lime glass, less than 10 nm in
size, were prepared by ion implantation. The implantation dose
was in the range of 0.5 to 2×1016 Ag
ions/cm2 and the beam current density
was varied from 0.5 to 2A/cm2. Here,
the beam current density strongly influences ion diffusion and
particle precipitation as well as compressive stress generation
around the particles due to thermal effects resulting from the
deceleration of silver ions. Stress relaxation can be achieved
by increased dose rates or thermal processing at elevated
temperatures. Based on RBS and HREM results, a possible route to
homogeneous distribution of Ag nanoparticles within the glass is
discussed with respect to their interesting optical properties. 相似文献
63.
G. E. Ntamack F. Chandezon B. Manil H. Lebius S. Tomita C. Guet M. G. Kwato Njock B. A. Huber 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,24(1-3):153-156
Highly charged sodium clusters produced in collisions
between neutral clusters and multiply charged ions are formed
within a large range of temperatures and fissilities, and
identified by means of a high-resolution reflectron-type
time-of-flight mass spectrometer ( m/m
14000). The limit of stability of these charged clusters is
experimentally investigated, and the time-of-flight spectra are
compared with theoretical spectra based on Monte-Carlo
simulations. The results indicate that the maximum fissility
(X) of stable clusters is
approaching the Rayleigh limit (X = 1) for larger clusters sizes. It is
mainly limited by the initial neutral cluster temperature (
T 100 K) and the energy
transfer in the ionizing collision. In addition, the comparison
between the measured and simulated spectra suggests for high
cluster charges a multi-fragmentation process, in which most of
charge is emitted, creating low charged residual cluster ions. 相似文献
64.
L. Kronik R. Fromherz E. Ko G. Ganteför J. R. Chelikowsky 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,24(1-3):33-36
We compare experimentally measured and
ab initio computed
photoelectron spectra of negatively charged deuterated silicon
clusters (
, 4m10, 0n2) produced in a plasma environment.
Based on this comparison, we discuss the kinetics and
thermodynamics of the cluster formation and the effect of
deuterium on the geometrical and electronic structure of the
clusters. 相似文献
65.
H. Nabika S. Deki 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,24(1-3):369-372
The effect of colloidal dispersion of silver on the
luminescent properties of Eu (III) complex with
pyridine-3,5-dicarboxylic acid (PyDC) was investigated. The
luminescence from Förster type europium complex was enhanced
several times with the presence of Ag colloid and the
enhancement factor showed Ag concentration dependence. The
observed enhancement effect was discussed in view of
surface-enhancement effect and optical absorption due to surface
plasmon resonance, both arising from excitation of surface
plasmon polariton. The coordination structure around Eu (III)
ion was also affected with the presence of Ag colloid, which
induced the change in the intensity ratio between two emission
bands of
5
D
0
7
F
1
and
5
D
0
7
F
2
transitions of Eu (III) ion. 相似文献
66.
Viscous flow of the resin in nano-imprinting lithography has been investigated. Flow behavior of the thermoplastic polymer was analyzed experimentally as well as numerically. Effects of process variables such as the temperature and the pressure and the stamp geometry on the filling pattern were studied. In order to observe the effect of stamp geometry, three different types of geometries were considered. Experiments were performed using polymethylmethacrylate (PMMA) sheets. Filled patterns were observed using a scanning electron microscopy (SEM). Fixed grid method along with the finite element method was used for numerical analysis. Numerical results exhibited a similar tendency as the experimental observation. 相似文献
67.
D. Lee S. Lee H. Kim D.-J. Jang 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,24(1-3):303-306
DNA-connected strings of gold nanoparticles are arranged
to form very uniformly annular arrays having various diameters
of a few micrometers by adjusting evaporation conditions as well
as the concentrations of gold nanoparticles and
phosphorothioate-modified oligonucleotides. The circles are
formed by the dry hole-opening mechanism rather than by the
Marangoni effect. However, their sizes are very diverse and
their circumferences are approaching to show single-particle
thinness instead of close-packed particle cluster thickness
owing to DNA-linked gold nanoparticle strands. 相似文献
68.
W. Vervisch C. Mottet J. Goniakowski 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,24(1-3):311-314
Morphology and atomic structure of supported Pd clusters
on MgO(100) substrate are investigated theoretically using a
mixed approach: a semi-empirical potential for the metal bonding
within the cluster and a potential fitted to
ab initio calculations for
the metal-oxide interaction. We find that the clusters adopt a
truncated pyramidal morphology in agreement with experimental
results. The detailed study of the epitaxial relation as a
function of cluster size shows the existence of a critical size
around 3 nm where elastic strain due to the misfit between the
substrate and the deposit is released by the introduction of
interfacial dislocations. 相似文献
69.
Ellison CJ Kim SD Hall DB Torkelson JM 《The European physical journal. E, Soft matter》2002,8(2):155-166
Fluorescence intensity measurements of chromophore-doped or -labeled polymers have been used for the first time to determine
the effects of decreasing film thickness on glass transition temperature, T
g, the relative strength of the glass transition, and the relative rate of physical aging below T
g in supported, ultrathin polymer films. The temperature dependence of fluorescence intensity measured in the glassy state
of thin and ultrathin films of pyrene-doped polystyrene (PS), poly(isobutyl methacrylate) (PiBMA), and poly(2-vinylpyridine)
(P2VP) differs from that in the rubbery state with a transition at T
g. Positive deviations from bulk T
g are observed in ultrathin PiBMA and P2VP films on silica substrates while substantial negative deviations from bulk T
g are observed in ultrathin PS films on silica substrates. The relative difference in the temperature dependences of fluorescence
intensity in the rubbery and glassy states is usually reduced with decreasing film thickness, indicating that the strength
of the glass transition is reduced in thinner films. The temperature dependence of fluorescence intensity also provides useful
information on effects of processing history as well as on the degree of polymer-substrate interaction. In addition, when
used as a polymer label, a mobility-sensitive rotor chromophore is demonstrated to be useful in measuring relative rates of
physical aging in films as thin as 10 nm.
Received 21 August 2001 相似文献
70.
D.K. Yu R.Q. Zhang S.T. Lee 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,15(1):57-63
The structures and energetics of carbon bridged C60 clusters (C
60
)
n
Cm have been studied by simulated annealing technique within the tight-binding molecular-dynamics. The “sp2 addition” ball-and-chain dimers exhibit odd-even alternations over the number of chain atoms, with the dimers containing
even chain atoms more stable against dissociation than their immediate neighbors containing odd chain atoms. In addition to
the usual “sp2 addition” dimers, a pentagon-linked C121 isomer and a hexagon-linked C122 isomer are also found to be stable. Based on our tight-binding calculations, trimers and larger clusters can be simply regarded
as being made up of independent or weakly interacting dimers, if the C-C60 joints on a single cage are not too close to each other. Large C60 clusters connected by chains each containing only one or two carbon atoms have similar stability to that of constituent dimers,
indicating the possibility to form stable C60-carbon polymers.
Received 17 January 2001 and Received in final form 26 February 2001 相似文献