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1.
Summary A computer interactive identification system is proposed which is based on the relationship between retention and molecular
properties such as the size and shape of polycyclic aromatic hydrocarbons (PAHs). This system offers an automatic analytical
process for liquid chromatography, providing a reliable identification of the separated components. The identification can
be further enhanced by the use of multiple detectors such as a multichannel UV detector. The system can be used for optimization
procedures, resulting in a highly automatic complex analytical system. 相似文献
2.
3.
理论估计传到地球上的引力波非常弱,激光干涉引力波探测器被设计用来探测引力波,在没有引力波传来时,激光干涉引力波探测器应该是零输出。为达到这样的目的,必须和众多的噪声作斗争。 相似文献
4.
ILki Kim Günter Mahler 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,54(3):405-414
We consider a single harmonic oscillator coupled to a bath
at zero temperature. As is well-known, the oscillator then has a
higher average energy than that given by its ground state. Here we
show analytically that for a damping model with arbitrarily discrete
distribution of bath modes and damping models with continuous
distributions of bath modes with cut-off frequencies, this excess
energy is less than the work needed to couple the system to the
bath, therefore, the quantum second law is not violated. On the
other hand, the second law may be violated for bath modes without
cut-off frequencies, which are, however, physically unrealistic
models.
An erratum to this article is available at . 相似文献
5.
QIAN Xian-Min Hon-Wah Tam 《理论物理通讯》2007,47(3):487-490
In this paper, we obtain a 1+1 dimensional integrable differential-difference model for the sine-Gordon equation by Hirota's discretization method. A bilinear Backlund transformation and the associated Lax pair are also proposed/or this model. 相似文献
6.
The band artifact in steady-state free precession can be reduced by synthesizing the multiple images obtained through different phase increments of successive radiofrequency pulses. Even though the complex summation method was reported to be effective in reducing the band artifact, it has the pitfalls of intensity abnormality and sensitivity to the phase abnormality. Two new methods have been developed for more reliable reduction of the band artifact than the complex summation method. One method is to sum the complex images partially and to take the maximum intensity of the partially summed images. The other method is to sum the free induction decay (FID) and primary echo components of the Fourier series that are obtained through Fourier analysis of the complex base images. Both proposed methods were compared with other magnitude (maximum intensity projection, spectrally decomposed synthesis, sum-of-squares, nonlinear averaging) and complex-based (complex summation, magnitude-weighted complex summation) methods experimentally at 3 T for the phantom and volunteer's head imaging. Both proposed methods were confirmed to maintain the advantage of the complex summation in reducing both the dark and bright band artifacts while reducing the intensity abnormality and sensitivity to the phase abnormality from that of the complex summation method over a wide range of flip angles and relaxation times. 相似文献
7.
Random fluctuations of the shot-noise power in disordered graphene nanoribbons are studied. In particular, we calculate the distribution of the shot noise of nanoribbons with zigzag and armchair edge terminations. We show that the shot noise statistics is different for each type of these two graphene structures, which is a consequence of the presence of different electron localizations: while in zigzag nanoribbons electronic edge states are Anderson localized, in armchair nanoribbons edge states are absent, but electrons are anomalously localized. Our analytical results are verified by tight binding numerical simulations with random hopping elements, i.e., off diagonal disorder, which preserves the symmetry of the graphene sublattices. 相似文献
8.
Damage and fracture prediction of plastic-bonded explosive by digital image correlation processing 总被引:3,自引:0,他引:3
M. Li J. Zhang C.Y. Xiong J. Fang J. M Li Y. Hao 《Optics and Lasers in Engineering》2005,43(8):856-868
By digital correlation processing of Scanning electronic microscopy (SEM) images, the paper presents the deformation and damage analysis of an energetic material—the plastic-bonded explosive (PBX) on mesoscopic scale. The analysis is made by observing the deformation field resulted from the digital image correlation (DIC) processing of the images corresponding to the loading steps and comparing with the surface profiles of the composite material so as to visualize the matter damage near a preset crack. The results show that the local deformation disturbance can reveal the material damage even happened underneath the specimen surface. The strain distribution in the front of the preset crack, can be used to predict the propagating route of the microcrack initiated from the tip of the pre-crack, which is related to the splitting fracture of the granular-based composite under compressive loading. 相似文献
9.
B. Spagnolo S. Spezia L. Curcio N. Pizzolato A. Fiasconaro D. Valenti P. Lo Bue E. Peri S. Colazza 《The European Physical Journal B - Condensed Matter and Complex Systems》2009,69(1):133-146
We investigate the role of the colored noise in two
biological systems: (i) adults of Nezara viridula (L.)
(Heteroptera: Pentatomidae), and (ii) polymer translocation. In the
first system we analyze, by directionality tests, the response of
N. viridula individuals to subthreshold signals plus noise
in their mating behaviour. The percentage of insects that react to
the subthreshold signal shows a nonmonotonic behaviour,
characterized by the presence of a maximum, as a function of the
noise intensity. This is the signature of the non-dynamical
stochastic resonance phenomenon. By using a “soft” threshold model
we find that the maximum of the input-output cross correlation
occurs in the same range of noise intensity values for which the
behavioural activation of the insects has a maximum. Moreover this
maximum value is lowered and shifted towards higher noise
intensities, compared to the case of white noise. In the second
biological system the noise driven translocation of short polymers
in crowded solutions is analyzed. An improved version of the Rouse
model for a flexible polymer is adopted to mimic the molecular
dynamics by taking into account both the interactions between
adjacent monomers and the effects of a Lennard-Jones potential
between all beads. The polymer dynamics is simulated in a
two-dimensional domain by numerically solving the Langevin equations
of motion in the presence of thermal fluctuations and a colored
noise source. At low temperatures or for strong colored noise
intensities the translocation process of the polymer chain is
delayed. At low noise intensity, as the polymer length increases, we
find a nonmonotonic behaviour for the mean first translocation time
of the polymer centre of inertia. We show how colored noise
influences the motion of short polymers, by inducing two different
regimes of translocation in the dynamics of molecule transport. 相似文献
10.
Abstract This article analyzes and validates through simulation the influence of fiber nonlinearity, dispersion, and loss on the Relative Noise Intensity (RIN) spectrum at fiber output in externally modulated optical single side band (OSSB) systems. The analysis includes the RIN generated by the laser source, the effect of the OSSB modulator, and noise generated by the in-line optical amplifiers. The analysis takes into account conversion between phase noise and intensity noise introduced by fiber transmission. It is shown that, depending on the operating conditions, the system performance may be predominantly affected either by the laser RIN or by the noise generated by the in-line optical amplifiers. The impact of the OSSB modulator can be relevant when the RIN of the system is dominated by the laser noise and should therefore be considered. 相似文献