Splitting rules of electronic miniband in Fibonacci superlattices: a gap map approach

The splitting rules of fragmental miniband in Fibonacci superlattices (FSLs) with arbitrary basis and generation orders are presented through a gap map diagram. Based on the gap map, we find the invariant conditions of the band structure splitting in the FSL for arbitrary generation orders. Moreover, the band structure splitting can be divided to form many regions, each having a similar pattern. In each region, the widths of most gap bands except two major gaps will decrease for increasing the generation order. It is interesting that the center and gap width of the major gaps will converge to constant values for increasing the generation order of the FSL. Based on the splitting rules displayed in the gap map, it is convenient to predict the fragmental band structure in the FSL for arbitrary generation orders and bases.     

Investigation of wavefront reconstruction by a two-lens system

A two-lens system was used to obtain wavefront reconstruction (WFR) by stimulated Raman and Brillouin backscattering with the beam focus varied over a large range of distances. A fixed scattering object was placed between two lenses, and the focus of the two-lens system was varied continuously from near the second lens, through the image of the scattering object on to infinity by moving the first lens accordingly. In all prior experiments reported in literature the image of the object was formed beyond the lens focus. Images reconstructed by stimulated Raman and Brillouin backscattering were obtained and their positions and magnifications were in agreement with the holographic model.     

Opposite-parity orthonormal function expansion for efficient full-vectorial modeling of holey optical fibers

An improved full-vectorial method exploiting the opposite-parity property of eigenmodes based on orthonormal-functions expansion is proposed to solve the wave equation for holey optical fibers. By use of the parity property of eigenmodes in symmetric structures, the number of orthonormal function integrals involved in the calculation is reduced, and the computation efficiency is greatly enhanced. The coupling between the two transverse field components is considered, and both dominant and minor field components can be calculated for the accurate modeling of fiber modes. This method is useful for efficiently modeling holey fibers, especially those with large air holes, in which the coupling effect that is due to refractive-index discontinuities is strong.     

Pharmacokinetics and oral bioavailability of epimedin C after oral administration of epimedin C and Herba Epimedii extract in rats

Epimedin C, an ingredient of Herba Epimedii, has potential for treatment of cardiovascular disease and bone loss. However, there is still no sensitive analytical method to monitor epimedin C in biological samples. The goal of this study was to develop a sensitive and reliable method based on a LC‐MS/MS for evaluating the pharmacokinetics of epimedin C after administration of Herba Epimedii in rat. Electrospray ionization in positive‐ion mode and multiple reaction monitoring were used to identify and quantitate active components. Analytes were separated by a reverse‐phase C₁₈ column. Liquid–liquid extraction using ethyl acetate, evaporation and reconstitution was used to plasma sample preparation. Mass transition of precursor ion → product ion pairs were monitored at m/z 823.4 → 313.1 for epimedin C and m/z 237.1 → 178.9 for carbamazepine (internal standard). A calibration curve gave good linearity (r > 0.999) over the concentration range 2.5–500 ng/mL. Pharmacokinetic data demonstrated that there was rapid distribution and slow elimination after epimedin C administration (1 mg/kg, i.v.). Oral bioavailabilities of epimedin C in the pure compound and in the Herba Epimedii were around 0.58% and 0.13%, respectively. The result suggests that other herbal ingredients of Herba Epimedii may suppress the oral bioavailability of epimedin C. Copyright © 2013 John Wiley & Sons, Ltd.     

Optical design and multi-objective optimization with fuzzy method for miniature zoom optics

In this paper a thinning L-type zoom lens design was proposed to exploit the reflecting and refracting surfaces connected by a prism. However, in the L-type designs, the modulation transfer function (MTF) value is comparatively low compared with that in its coaxial counterparts. If we increase the MTF, that would cause the relative illuminace (RI) degradation. We propose a combination of the Taguchi method and fuzzy approach to improve both the RI and MTF in L-type zoom systems. The resulting experimental values of orthogonal array L9 of the Taguchi method were used as inputs for fuzzy approach to obtain the MPCI value. The MPCI value was then analyzed by variance, revealing that the two most significant factors were (1) the surface 7 to image length and (2) the semi-aperture of the front element. In our proposed method, the appropriate weight of MTF and RI for the inputs of fuzzy controllers increased the MTF by 3.74%, but the RI only reduced by 0.13% in the systematic wide-angle end, respectively.     

Theorems on the limit analysis dealing with the yield condition expressed by the sum of the homogeneous linear form of stress tensor and the homogeneous quadratic form of stress tensor

In this paper a generalized variational principle on the limit analysis dealing with the yield condition expressed by the sum of the homogeneous linear form of stress tensor and the homogeneous quadratic form of stress tensor is suggested.This variational principle can be applied to the limit analysis in rock mechanics and it takes the situation, in which the yield condition is expressed by the homogeneous linear form of stress tensor or the homogeneous quadratic form of stress tensor, as its special case.     

Giant persistent currents in quasiperiodic mesoscopic rings

Giant persistent currents that occur in quasiperiodic Thue–Morse array of mesoscopic rings are proposed. As the order of the system increases, the maximum persistent current increases exponentially. The giant persistent current in a system with higher order is greater than that in traditional structures. It is found that the maximum persistent current occurs in the ring near the middle position of the array. The persistent current is also proportional to the sharpness of the transport resonance, which is dependent on the width of the allowed band in the bandstructure. A rule to determine the occurrence energy of the giant persistent currents for a system with arbitrary order is also proposed.     

Separation and Migration Behavior of Dichlorophenols in β‐Cyclodextrin‐Modified Capillary Zone Electrophoresis

The separation and migration behavior of six isomeric dichlorophenols (DCPs) in cyclodextrin‐modified capillary zone electrophoresis (CD‐CZE) using a phosphate‐borate buffer at alkaline pH with β‐CD and hydroxypropyl‐β‐CD (HP‐β‐CD) as electrolyte modifiers were investigated. The influence of buffer pH and the concentration of β‐cyclodextrins were examined. The results indicate that baseline separation of six isomeric DCPs can be achieved with addition of β‐CD concentration in the range of 2.0‐10 mM or HP‐β‐CD concentration in the range of 4.0‐10 mM at pH 10.0. Binding constants of DCPs to β‐CDs were evaluated for a better understanding of the interaction of DCPs with β‐CDs.     

An Analysis of Exhaust Emission of the Internal Combustion Engine Treated by the Non-Thermal Plasma

Industries’ air pollution causes serious challenges to modern society, among them exhaust gases from internal combustion engines, which are currently one of the main sources. This study proposes a non-thermal plasma (NTP) system for placement in the exhaust system of internal combustion engines to reduce the toxic contaminants (HC, CO, and NO_x) of exhaust gases. This NTP system generates a high-voltage discharge that not only responds to the ion chemical reaction to eliminate NO_x and CO, but that also generates a combustion reaction at the local high temperature of plasma to reduce HC. The NTP system was designed on both the front and rear of the exhaust pipe to analyze the difference of different exhaust flow rates under the specified frequency. The results indicate that the NTP system can greatly reduce toxic contaminants. The NTP reactor placed in the front of exhaust pipe gave HC and CO removal efficiency of about 34.5% and 16.0%, respectively, while the NTP reactor placed in the rear of exhaust pipe gave NO_x removal efficiency of about 41.3%. In addition, the voltage and material directly affect the exhaust gases obviously. In conclusion, the proposed NTP system installed in the exhaust system can significantly reduce air pollutants. These results suggest that applying NTP to the combustion engine should be a useful tool to simultaneously reduce both emissions of NO_x and CO.