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71.
It is observed that the efficiency of the DCM dye dissolved in ethylene glycol benzyl alcohol can be enhanced if the dye is
preheated at a temperature of 150 °C. Peak powers as high as 1.5 W have been achieved with a single-mode ring dye laser at
640 nm when pumped by 9 W (all lines) from an argon-ion laser. The wavelength region has been also extended beyond both ends
of the tuning curve compared to a conventionally prepared DCM dye.
Received: 3 September 1999 / Revised version: 9 December 1999 / Published online: 23 February 2000 相似文献
72.
A comparative experimental study was conducted to examine the effect of fluid-fluid interfacial reaction on immiscible displacements
in a wide range of mobility ratios. The nonreactive fluid pair consisted of paraffin oil/decane mixtures and water. In order
to formulate a reactive system, linoleic acid (10 mol/m3) was added to the oil and sodium hydroxide (25 mol/m3) was added to the water. The experiments were performed in a square Hele-Shaw cell, simulating a quarter of a reversed five-spot
pattern. Displacement patterns produced by reactive and nonreactive fluid pair systems were fundamentally different from each
other. The recovery in the reactive system was generally higher than in the non-reactive system. The recovery at breakthrough
for both the reactive and the non-reactive systems increased with a decrease in the viscosity of oil. In the non-reactive
system, the recovery at one hour after breakthrough increased with the decrease in oil viscosity and became constant at 63%
when the oil viscosity reached 6.86 mPa · s. In the reactive system the recovery at one hour after breakthrough was nearly
100% regardless of oil phase viscosity. When the oil viscosity was lower than the viscosity of the displacing phase (favorable
mobility ratio), the recovery percentage was high. However, the jagged character of the displacement front characteristic
of the reactive system was still preserved. 相似文献
73.
M. A. Kalyar S. Mahmood S.-U. Haq N. Amin M. A. Baig 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,41(2):229-236
We report a systematic line shape analysis study of the 6p7p configuration
based 1P1, 3D1 and 3P1 autoionizing
resonances in barium using a Nd:YAG pumped dye laser system in conjunction
with a thermionic diode ion detector. The even parity isolated autoionizing
resonances have been approached via four intermediate states 6 snp
1P1 (6 ≤n ≤8) and 5d6p 1P1. A comparison of
the Fano parameters of the resonance profiles reveals that the width of an
autoionizing resonance is independent of the excitation path while the line
profile parameter changes with the selection of different intermediate
states. 相似文献
74.
N. M. Shaikh S. Hafeez B. Rashid M. A. Baig 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,44(2):371-379
In the present work, we have studied the spatial evolution of the aluminum
plasma produced by the fundamental (1064 nm), second (532 nm) and third (355
nm) harmonics of a Q-switched pulsed Nd:YAG laser. The experimentally
observed line profiles of neutral aluminum have been used to extract the
excitation temperature using Boltzmann plot method whereas the electron
number density has been determined from the Stark broadened profiles.
Besides we have studied the variation of excitation temperature and electron
number density as a function of laser irradiance at atmospheric pressure. In
addition, we have performed quantitative analysis of photon absorption and
vapor ionization mechanism at three laser wavelengths and estimated the
inverse bremsstrahlung (IB) absorption and photoionization (PI) coefficients.
The validity of the assumption of local thermodynamic equilibrium is
discussed in the light of the experimental results. 相似文献
75.
Toledano P Figueiredo Neto AM de Sant'Ana ZA 《Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics》2000,61(1):486-492
Experimental investigations of lyotropic cholesterics fluids are presented which show that changes in the shape anisotropy and chirality of the micellar population determine the topology of the temperature-concentration phase diagrams. For given amounts of the substances which induce the chirality and modify the shape anisotropy of the micelles, two distinct biaxial cholesteric phases are disclosed in the phase diagrams. This is interpreted in the framework of the catastrophe theory of phase transitions. 相似文献
76.
77.
A Reggeon Field Theory (RFT) which incorporates the Pomeron and thef-pole is presented. The constrains on the renormalization group β-functions imposed by thef-dominance of the Pomeron are derived. We show that these constrains are satisfied by the RFT at least up to third order in the coupling constants. 相似文献
78.
We present the optimal scheme for estimating a pure qubit state by means of local measurements on N identical copies. We give explicit examples for low N. For large N, we show that the fidelity saturates the collective measurement bound up to order 1/N. When the signal state lays on a meridian of the Bloch sphere, we show that this can be achieved without classical communication. 相似文献
79.
80.
Hae-Chul Park Irshad Ahmed Baig Sang-Choon Lee Ji-Young Moon Moon-Young Yoon 《Applied biochemistry and biotechnology》2014,174(2):793-802
Salmonella enterica subsp. enterica ser. enteritidis and Salmonella enterica subsp. enterica ser. typhimurium are the most common and severe food-borne pathogens responsible for causing salmonellosis in humans and animals. The development of an early and ultra-sensitive detection system is the first critical step in controlling this disease. To accomplish this, we used the cell systematic evolution of ligands by exponential enrichment (Cell-SELEX) technique to identify single-stranded DNA (ssDNA) aptamers to be used as detection probes that can specifically bind to S. enteritidis and S. typhimurium. A total of 12 target-specific ssDNA aptamers were obtained through ten rounds of Cell-SELEX under stringent selection conditions, and negative selection further enhanced the selectivity among these aptamers. Aptamer specificity was investigated using the gram-negative bacteria E. coli and P. aeruginosa and was found to be much higher towards S. enteritidis and S. typhimurium. Importantly, three candidate aptamers demonstrated higher binding affinities and the dissociation constants (Kd) were found to be in the range of nanomolar to submicromolar levels. Furthermore, individual aptamers were conjugated onto polyvalent directed aptamer polymer, which led to 100-fold increase in binding affinity compared to the individual aptamers alone. Taken together, this study reports the identification of higher affinity and specificity ssDNA aptamers (30mer), which may be useful as capture and detection probes in biosensor-based detection systems for salmonellosis. 相似文献