90 research outputs found
Nonlinear optical properties of a three-dimensional anisotropic quantum dot
The linear and nonlinear optical properties in a three-dimensional
anisotropic quantum dot subjected to a uniform magnetic field directed with
respect to the axis have been investigated within the compact-density
matrix formalism and the iterative method. The dependence of the linear and
nonlinear optical properties on characteristic frequency of the parabolic
potential, on the magnetic field and on the incident optical intensity is
detailedly studied. Moreover, take into account the position-dependent
effective mass, the dependence of the linear and nonlinear optical properties
on the dot radius is investigated. The results show that the optical absorption
coefficients (ACs) and refractive index (RI) changes of the anisotropic quantum
dot (QD) have strongly affected by these factors, and the position effect also
plays an important role in the optical ACs and RI changes of the anisotropic
QD.Comment: 12pages 8 figures, accpeted for publication in solid state
communication
Nonlinear optical properties in a quantum well with the hyperbolic confinement potential
We have performed theoretical calculation of the nonlinear optical properties
in a quantum well (QW) with the hyperbolic confinement potential. Calculation
results reveal that the transition energy, oscillator strength, second-order
nonlinear optical rectification (OR), geometric factor and nonlinear optical
absorption (OA) are strongly affected by the parameters () of
the hyperbolic confinement potential. And an increment of the parameter
reduces all these physical quantities, while an increment of the
parameter enhances them, but not for geometric factor. In addition, it
is found that one can control the optical properties of QW by tuning these
parameters.Comment: 16pages,6 figures,Accepted for publication in Physica
Study on Spatial Distribution of Soil Available Microelement in Qujing Tobacco Farming Area, China
AbstractDescriptive analysis characteristics and spatial variation characteristics of soil available microelements were studied based on SPSS and GIS Soil available microelements spatial distribution maps were created with ordinary Kriging method. The results indicate that, 7 available microelements in tobacco soil obey lognormal distribution, all the available microelements were intermediate variability; Anisotropic structure of available microelements of tobacco soil varies evidently, spatial variability of available B was mainly caused by random factors, and others’ spatial variability were caused by structural factors and random factors; Spatial distribution maps show that, available B was widely deficient in tobacco soil of Qujing farming area, ‘lower level’ and ‘low level’ taken 7.74% and 68.20%, respectively available Zn distribution was moderate, only 1.32% of the area lack of Zn, available Cu, available Fe and available Mn were extremely high in the whole extension, available Mo was deficient in part of the region with 28.38%, water soluble Cl was higher than critical value(30mgkg−1)in the most of Qujing farming area, which taken 38.86%
Relative posture-based kinematic calibration of a 6-RSS parallel robot by optical coordinate measurement machine
In this article, a relative posture-based algorithm is proposed to solve the kinematic calibration problem of a 6-RSS parallel robot using the optical coordinate measurement machine system. In the research, the relative posture of robot is estimated using the detected pose with respect to the sensor frame through several reflectors which are fixed on the robot end-effector. Based on the relative posture, a calibration algorithm is proposed to determine the optimal error parameters of the robot kinematic model and external parameters introduced by the optical sensor. This method considers both the position and orientation variations and does not need the accurate location information of the detection sensor. The simulation results validate the superiority of the algorithm by comparing with the classic implicit calibration method. And the experimental results demonstrate that the proposal relative posture-based algorithm using optical coordinate measurement machine is an implementable and effective method for the parallel robot calibration
A Crosstalk between the Smad and JNK Signaling in the TGF-β-Induced Epithelial-Mesenchymal Transition in Rat Peritoneal Mesothelial Cells
Transforming growth factor β (TGF-β) induces the process of epithelial-mesenchymal transition (EMT) through the Smad and JNK signaling. However, it is unclear how these pathways interact in the TGF-β1-induced EMT in rat peritoneal mesothelial cells (RPMCs). Here, we show that inhibition of JNK activation by introducing the dominant-negative JNK1 gene attenuates the TGF-β1-down-regulated E-cadherin expression, and TGF-β1-up-regulated α-SMA, Collagen I, and PAI-1 expression, leading to the inhibition of EMT in primarily cultured RPMCs. Furthermore, TGF-β1 induces a bimodal JNK activation with peaks at 10 minutes and 12 hours post treatment in RPMCs. In addition, the inhibition of Smad3 activation by introducing a Smad3 mutant mitigates the TGF-β1-induced second wave, but not the first wave, of JNK1 activation in RPMCs. Moreover, the inhibition of JNK1 activation prevents the TGF-β1-induced Smad3 activation and nuclear translocation, and inhibition of the TGF-β1-induced second wave of JNK activation greatly reduced TGF-β1-induced EMT in RPMCs. These data indicate a crosstalk between the JNK1 and Samd3 pathways during the TGF-β1-induced EMT and fibrotic process in RPMCs. Therefore, our findings may provide new insights into understanding the regulation of the TGF-β1-related JNK and Smad signaling in the development of fibrosis
The negatively charged exciton in double-layer quantum dots
The hyperangular equation for charged semiconductor complexes in a
double-layer harmonic quantum dot was solved numerically by using the
correlated hyperspherical harmonics as basis functions. By using this
method, we have calculated the energy spectra of the low-lying states of a
charged exciton as a function of the radius of the quantum dot and the binding
energy spectra of the ground state as a function of the radius of the quantum
dot for a few values of the distance between the vertically coupled dots and
the electron-to-hole mass ratio
How does Privacy Transfer Affect the Value Co-creation Behavior of Gray Privacy Products? --Female Bras as an Example
Due to the particularity of gray privacy products, purchasing involves more privacy information of consumers, thus affecting value co-creation behavior. Based on the value co-creation theory and privacy calculus theory, this paper takes the female bra as an example to construct the research hypothesis and model influencing the consumer value co-creation behavior under the circumstance that online consumers are concerned about privacy. This article in the form of questionnaire survey to collect empirical data, uses the structural equation model to explain privacy concern about the impact of perceived risk and perceived benefits and mechanisms, as well as the perceived risk and perceived benefits of consumer value to create the behavior and mechanism of action, and discusses the privacy transfer how to affect the consumer\u27s perceived risk and perceived benefits. The results reveal the role of privacy concern and the complexity of the influencing factors of privacy concern and privacy transfer on consumers\u27 value co-creation behavior
On a laxity-based real-time scheduling policy for fixed-priority tasks and its non-utilization bound
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