We present a scheme to implement quantum computation in decoherence-free subspaces (DFSs) with four atoms in a single-mode cavity. A four-dimensional DFS is constituted to protect quantum information when the full symmetry of interaction between system and environment is broken in a specific way, and entangling two-qubit logic gates and noncommuting single-qubit gates are implemented in such DFS. The gate fidelity is numerically calculated, and the feasibility of the approximations taken in this work is verified based on the numerical calculations. 相似文献
Toluene was decomposed in a surface discharge plasma reactor packed with various zeolites. The positioning effect of the zeolite bed was also investigated Reactor-B, in which the zeolite bed was located upstream, performed much better than Reactor-A, in which the zeolite bed was located downstream. Furthermore, the decomposition efficiency in Reactor-B increased with the capacity for toluene adsorption on zeolite, while that in Reactor-A did not. The toluene adsorbed in micropores was not decomposed effectively by direct electron impact, but was decomposed by active oxygen species generated in the plasma zone on the zeolite surface. A good correlation was also observed between toluene decomposition and ozone consumption in the downward-type reactor. 相似文献
A new mixed-valent iron MOF, formulated as Fe3O(F4BDC)3(H2O)3·(DMF)3.5 (1), has been synthesized by using a perfluorinated linear dicarboxylate to link trigonal prismatic Fe3(μ3-O)(O2C–)6 clusters. The structure refinement based on single crystal X-ray diffraction data collected from 1 reveals the material exhibits the acs topology with large channels along the crystallographic c-axis. Due to the presence of fluorine atoms the organic link, 2,3,5,6-tetrafluorobenzene-1,4-dicarboxylate (F4BDC), has a 63° torsion angle between the carboxylate and aromatic planes, resulting in larger channels compared to those in the isoreticular material MOF-235. While few iron-based MOFs have demonstrated porosity, nitrogen and hydrogen sorption experiments carried out at 77 K proved the porosity of outgassed 1, which has a Langmuir surface are of 635 m2/g and a gravimetric capacity of 0.9 wt% of hydrogen at 1 bar. 相似文献
Luminescent yttrium aluminum garnet (YAG, Y3Al5O12) nanoparticles doped with Eu (10 at%) were synthesized in batch-type and continuous-type supercritical water (SCW) reactors.
In the case of the continuous-type SCW method, the particles of YAG: Eu phosphors were much smaller and demonstrated a uniform
spherical-like shape. Inversely, in the case of the batch-type SCW method, a needle-like or elliptical-like shape was formed
because a finite amount of time was required to reach SCW conditions from ambient conditions. However, the emission intensity
of YAG: Eu phosphors synthesized by using the batch-type SCW method was stronger. Therefore, it is concluded that the continuous-type
SCW method is superior to the batch-type SCW method from the viewpoint of the particle size and shape, but the luminescence
property of phosphors in the continuous-type SCW method needs to be improved. In addition, a calcination process slightly
improved the luminescence intensities of YAG: Eu phosphors generated by using either the batch-type or continuous-type SCW
methods. 相似文献
Dye sensitized solar cells (DSSCs) have been receiving significant attention because they have many advantages compared to
conventional organic solar cells. It has been known that the photovoltaic characteristics of DSSC are highly dependent on
the adsorption properties of dyes on TiO2 films. To analyze the surface heterogeneity of TiO2 surfaces, single-phase anatase nanocrystallite titanium films were prepared by sol-gel method using the hydrolysis reaction
of titanium tetraisopropoxide under acidic condition and characterized by XRD, FE-SEM and BET analysis. The adsorption energy
distribution functions were calculated by the generalized nonlinear regularization method. It was found that the shape and
the intensity of the adsorption energy distribution curve determined were highly related with the physical properties (i.e.,
geometrical heterogeneity) and chemical characteristics (i.e., energetic heterogeneity) of nanocrystalline TiO2 for DSSC. 相似文献
Spin dynamics of3He-4He dilute solution have been studied in the collisionless regime by NMR methods. In cw NMR experiments, we observed spin waves in a magnetic field gradient. The frequency difference between the first mode and the others obeyed a two-thirds power law in the strength of the field gradient. By using a pulsed NMR method, nonlinear spin dynamics were studied. We observed the large amplitude spin waves after an rf pulse. The frequency of each spin-wave mode depended on the tipping angle. By using the parameter determined in the present experiment, the numerical calculated results based on Leggett-Rice theory are in good agreement with the results of the pulsed NMR experiments. 相似文献
In this paper, we consider a problem of global stabilization for a class of approximately feedback linearized nonlinear systems. In order to handle more nonlinearity over the existing results, we provide a new feedback controller with two gain-scaling factors and we show that more nonlinearity can be treated by our control scheme. Moreover, we analytically show that the considered nonlinear systems can be stabilized by the proposed controller. Through comparison practical examples, we illustrate the improved features of our proposed control method.
In this paper, we consider a problem of global asymptotic stabilization for nonlinear systems with the perturbed nonlinearity. We provide a stabilizing controller with two gain-scaling factors and a new controller design method with matrix inequality approach. In particular, we provide a new procedure for selecting gain-scaling factors which are associated with stabilizing the closed-loop system. As a result, our proposed control method widens the class of considered nonlinear systems and yields better control performance over the existing methods. Via several comparison examples, we illustrate the improved features of the proposed control method over the existing ones.
It has been observed that the forming limit curve at fracture (FLCF) of steel sheets, with a relatively higher ductility limit
have linear shapes, similar to those of a bulk forming process. In contrast, the FLCF of sheets with a relatively lower ductility
limit have rather complex shapes approaching the forming limit curve at neck (FLCN) towards the equi-biaxial strain paths.
In this study, the FLCFs of steel sheets were measured and compared with the fracture strains predicted from specific ductile
fracture criteria, including a criterion suggested by the authors, which can accurately describe FLCFs with both linear and
complex shapes. To predict the forming limit for hydro-mechanical deep drawing of steel sheets, the ductile fracture criteria
were integrated into a finite element simulation. The simulation, results based on the criterion suggested by authors accurately
predicted the experimetal, fracture limits of steel sheets for the hydro-mechanical deep drawing process. 相似文献