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951.
952.
F. P. Heßberger 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,45(1):33-37
Isotopes of elements up to Z = 113 have been synthesized
using medium heavy projectiles and target nuclei around doubly
magic 208Pb. Synthesis of still heavier elements in reactions
of 48Ca projectiles with actinide target nuclei has been
reported. To obtain more information about production mechanism of
transfermium isotopes nuclear reaction studies including
investigations of massive transfer were resumed at SHIP, GSI.
Nuclear structure investigations at SHIP have been concentrated so
far mainly on systematic investigations of low lying Nilsson
levels in odd-mass nuclei. Recently this field has been extended
to decay studies of isomeric states in nobelium nuclei at E* > 1 MeV. 相似文献
953.
V. I. Telnov 《Pramana》2007,69(6):957-961
At linear colliders, the e
+
e
− luminosity is limited by beam-collision effects, which determine the required emittances of beams in damping rings (DRs).
In γγ collisions at the photon collider, these effects are absent, and so smaller emittances are desirable. In the present damping
ring designs, nominal DR parameters correspond to those required for e
+
e
− collisions. In this note, I would like to stress once again that as soon as we plan the photon collider mode of ILC operation,
the damping ring emittances are dictated by the photon collider requirements — namely, they should be as small as possible.
This can be achieved by adding more wigglers to the DRs; the incremental cost is easily justified by a considerable potential
improvement of the γγ luminosity. No expert analysis exists as of now, but it seems realistic to obtain a factor five increase of the γγ luminosity compared to the ‘nominal’ DR design.
相似文献
954.
Characterization of SiC and Si<Subscript>3</Subscript>N<Subscript>4</Subscript> nanoparticles and their aqueous dispersions 总被引:1,自引:0,他引:1
Nanoparticles of SiC and Si3N4 were previously used to obtain electroless NiP/particles nanocomposites. The incorporation process was very different, depending
on the particle: SiC tended to agglomerate and had a high incorporation level; Si3N4 particles were not aggregated, but their incorporation level was very low. To try to explain these differences, the particles
and their aqueous dispersions were characterized. Although the as-received products were both oxidized and of the identical
mean size, results showed that the size distributions and the surface oxidation products were rather different. The zeta potential
in water dispersions was similar and negative for both particles but, as the electrolyte ions were introduced, it showed a
different evolution: nitride particles retained a small negative charge and carbide was almost uncharged. The overall results
obtained in this study explain the different behavior of both ceramic particles and provide possible solutions to improve
their co-deposition with nickel. 相似文献
955.
Bao-Long Liang Ji-Suo Wang Hong-Yi Fan 《International Journal of Theoretical Physics》2007,46(7):1779-1785
Wigner function in phase space has its physical meaning as marginal probability distribution in coordinate space and momentum
space respectively, here we endow the Wigner function with a new physical meaning, i.e., its marginal distributions’ statistical
average for q
2/(2C) and p
2/(2L) are the energy stored in capacity and in inductance of a mesoscopic L-C circuit at finite temperature, respectively.
PACS numbers: 03.65.-w, 73.21.-b 相似文献
956.
Using results for the distribution of perimeters of random polygons arising from random lines in a plane, we obtain new analytic
approximations to the distributions of areas and local line densities for random polygons and compute various limiting properties
of random polygons. Using simulation, we show that the lengths of adjacent sides of polygons generated by random line processes
in the plane are correlated with ρ=0.616±0.001. 相似文献
957.
N. Ikeda 《Physica A》2007
We propose a model of time evolving networks in which a kind of transport between vertices generates new edges in the graph. We call the model “Network formed by traces of random walks”, because the transports are represented abstractly by random walks. Our numerical calculations yield several important properties observed commonly in complex networks, although the graph at initial time is only a one-dimensional lattice. For example, the distribution of vertex degree exhibits various behaviors such as exponential, power law like, and bi-modal distribution according to change of probability of extinction of edges. Another property such as strong clustering structure and small mean vertex–vertex distance can also be found. The transports represented by random walks in a framework of strong links between regular lattice is a new mechanisms which yields biased acquisition of links for vertices. 相似文献
958.
Stock indexes for some European emerging markets are analyzed using an investment-horizon approach. Austrian ATX index and Dow Jones have been studied and compared with several emerging European markets. The optimal investment horizons are plotted as a function of an absolute return value. Gain–loss asymmetry, originally found for American DJIA index, is observed for all analyzed data. It is shown, that this asymmetry has different character for emerging and for established markets. For established markets, gain curve lies typically above loss curve, whereas in the case of emerging markets the situation is just the opposite. We propose a measure quantifying the gain–loss asymmetry that clearly exhibits a difference between emerging and established markets. 相似文献
959.
The objective of this paper is to examine causality and feedback relationships between primary commodity prices and US inflation. To this end, the bivariate noisy Mackey–Glass process recently developed by Kyrtsou and Labys [Evidence for chaotic dependence between US inflation and commodity prices, J. Macroecon. 28(1) (2006) 256–266] has been applied to assess this relationship. Results obtained support evidence in favour of causality, which can help to identify the influences of speculative price behaviour on inflation. 相似文献
960.
Knowledge of in-situ fuel distributions in practical combustion devices, such as internal combustion engines, is crucial for research and devlopment purposes. Numerous imaging techniques, mostly based on laser-induced fluorescence (LIF), have been developed and yield high levels of 2-D spatial information, but generally lack the temporal resolution (frame rates) necessary to resolve important timescales at sub-millisecond levels for sustained times. A planar LIF technique for quantitatively visualizing fuel distribution is presented which gives not only high spatial resolution, but also high temporal resolution. Using a high-speed CMOS camera, a lens-coupled image intensifier, and frequency-tripled diode-pumped Nd:YAG laser allows for capturing LIF images of biacetyl that is used as a fluorescence tracer at 12 kHz (one crank-angle resolution at 2000 RPM) for hundreds of consecutive engine cycles. The LIF signal strength of biacetyl doped in iso-octane is shown to vary substantially over a wide range of temperatures and pressures. The low absorption coefficient at 355 nm and a longpass filter in the detection path exclude bias errors due to laser beam attenuation and fluorescence trapping. An intensifier gate time of 350 ns is shown to suppress the detection of phosphorescence signals under practical conditions. An example for a quantitative high-speed measurement of fuel concentration at varying pressure and temperature conditions is presented. Quantitative equivalence ratio maps are shown for the fuel injection event within a single cycle in a spark-ignition direct-injected engine, showing the ability of the technique to not only reveal static fuel concentration maps, but also the motion of the fuel cloud along with very steep gradients. Spray velocities determined from the moving fuel cloud are in agreement with previous particle image velocimetry measurements. 相似文献