Journal of Russian Laser Research - In this work, we study quantum coherence, the degree of mixedness, and total quantum correlation in two interacting superconducting charge qubits (SCQs) in both... 相似文献
In this paper, we construct photon-added f-deformed coherent states (PAf-DCSs) for nonlinear bosonic fields by discussing Klauder's minimal set of conditions required to obtain coherent states. Using this set of nonlinear states, we propose a very useful scheme for generating the maximal amount of entanglement via unitary beam splitters for different strength regimes of the input field α, deformation q and excitation number m. Therefore, the possibility to create highly entangled states and to control the entanglement is proposed. Moreover, the condition for a maximal and separable output beam state is obtained. Finally, we examine the statistical properties of the PAf-DCSs through the Mandel parameter and exploit a connection between this quantity and the behavior variation of the output state entanglement. Our result may open new perspectives in different tasks of quantum information processing. 相似文献
We numerically simulate quantum coherence in a system of two qubits interacting with a reservoir for non-Markovian channels. The explicit form of the master equation is taken in terms of density-operator elements and is solved according to the initial conditions. In particular, we consider the effect of an Ohmic reservoir (OR) with Lorentz–Drude regularization (LDR) on the extent of coherence during dynamics. We describe the dynamical behavior of the coherence for low, intermediate, and high-temperature reservoirs. We explain the effect of the ratio of the cutoff frequency (CF) to the quantum system frequency and the effect of temperature on the quantum coherence. We show that a decreasing ratio enhances coherence, while an increasing temperature decreases it.
We described here a solid-phase microextraction procedure used to extract six urea pesticides — chlorsulfuron, fluometuron, isoproturon, linuron, metobromuron and monuron — from environmental samples. Two polydimethylsiloxanes and a polyacrylate fiber (PA) are compared. The extraction time, pH control, addition of NaCl to the water and the influence of organic matter such as humic acid on extraction efficiency were examined to achieve a sensitive method. Determination was carried out by gas chromatography with nitrogen–phosphorus detection. The proposed method requires the extraction of 2 ml of sample (pH 4, 14.3%, w/v, NaCl) for 60 min with the PA fiber. The limits of detection range from 0.04 for linuron to 0.1 μg/l for fluometuron and monuron and the relative standard deviations at the 1 μg/l level are between 15% and 9%. The apparent fiber–water distribution constants (Kfw) calculated in the proposed conditions were in the order of 103. Phenylurea herbicides were indirectly determined in the form of their derived anilines and chlorsulfuron in the form of an aminotriazine as confirmed by gas chromatography–mass spectrometry. Natural waters were utilized to validate the final procedure. However, a unequivocal identification in unknown environmental samples should be done by LC–MS. The presence of dissolved organic matter such as humic acid produces losses during the extraction step. Adding sodium chloride to the sample compensates for this effect. 相似文献
A new method based on extraction with octylsilica (C8) followed by liquid chromatography coupled with fluorescence detection (LC-FLD) was studied to determine ochratoxin A (OTA) from cereals and cereal products. Optimization of different parameters, such as type and amount of solid phase, type and volume of eluent and amount of sample were carried out. Recovery of OTA from rice samples spiked at 10 ng/g level was of 86% with relative standard deviation of 5%. The limits of detection and quantification of the proposed method were 0.25 and 0.75 ng/g, respectively. Furthermore, LC-FLD after of OTA methylation and liquid chromatography coupled to mass spectrometry with an electrospray interface were used for confirmation of OTA in all studied samples. The proposed method was applied to 62 samples of cereals and cereal products and the presence of OTA was found in seven samples. 相似文献
The surface of the thermionic emitters LaB6 and CeB6 was investigated as a function of temperature by means of XPS, Auger electron spectrosopy and the Kelvin method. The hexaborides are sensitive to oxidation at room temperature, a thin layer of rare earth oxide and boron oxide having been detected at their surfaces. This study has shown the influence of surface carbon on the Auger line intensities of lanthanum and boron in the case of LaB6. A surface cleaning by ionic bombardment leads to a preferential erosion of the rare earth with respect to boron. One may conclude that the emission mechanism in hexaborides is an intrinsic property of the material. The hypothesis previously proposed by other authors, that the low work function may be due to the presence of a layer of rare earth metal on the LaB6 substrate was not confirmed. 相似文献
Summary Degradation products of chlorsulfuron, chlortoluron, diuron, fluometuron, isoproturon, linuron, metabenzthiazuron, metobromuron,
and monuron formed in the gas chromatographic injector have been used for identification of the respective herbicides. Mass
spectra of the derived compounds were obtained with a quadrupole mass spectrometric detector working in scan mode (20–450
amu). The compounds generated often depended on the solvent used for phenylurea herbicide injection (ethanol, methanol, dichloromethane,
and acetonitrile). When methanol and ethanol were used as solvents the major products formed from phenylureas were carbamic
acid esters. When acetonitrile or dichloromethane were used the main derivatives were phenylisocyanates. Chlorsulfuron and
metabenzthiazuron, however, generated a triazine plus a phenylsulfonamide and a benzothiazolamine, respectively, irrespective
of the solvent used. Linuron and diuron behaved similarly and gave degradation products with the same mass spectra. The thermal
reactions occurred instantaneously in the injector block and were promoted by the high temperature selected (300°C).
Detemination of the compounds derived from urea herbicides, by use of a 30 m BP10 column and a selected ion registering (SIR)
program based on two or three ions, can be used for sensitive detection of the presence of urea herbicides in environmental
extracts. With standards in methanol instrument detection limits ranged from 0.1 pg for chlorsulfuron (detected as 2-chlorobenzensulfonamide)
to 1 pg for monuron and metobromuron (both detected as their carbamic acid methyl esters).RSD were below 9% at the 5 ng L−1 level. The response was linearly dependent on quantily (r>0.9986) in the 5 ng L−1 to 25 μg L−1 range. Unequivocal identification of some phenylurea herbicides was not always possible because some herbicides with similar
structures, for example diuron and linuron, gave the same derivative. 相似文献
In this paper, we investigate the entanglement of the field interacting with Ξ-type moving three-level atom. The results show that the deformed effect, atomic motion and the field-mode structure play important roles in the evolution of entanglement and marginal atomic Q-function behavior. We test this observation with experimentally accessible parameters and some new aspects are obtained. 相似文献