光转向投影系统和用于HDR显示设备的属性

本文首先总结了光转向放映机在影院应用的最新进展,然后根据新放映机和现有显示特征提出增加两项简单的显示属性:最大平均亮度和峰值(彩色)原色亮度,以便更好地预测HDR显示器的内容可再现性。为检验新属性的应用效果,将新属性在商用HDR电视系统上进行了专业内容测试,发现新属性可以更好地预测某一像素值是否在显示能力范围内。

基于光转向的高动态范围激光显示

广色域(WCG)和高动态范围(HDR)显示能够真实地还原现实场景,是高性能显示力求实现的方向。基于相位调制的光转向器件可以改变光场的能量分布,采用了光转向技术的激光显示系统兼具WCG和HDR特性,具有优良的显示效果。在影院、投影增强现实等对显示效果要求高的使用场景中有广泛的应用前景。动态范围的拓展能力依赖于光转向照明调制的算法,基于此,提出了一种新的光转向调制算法,利用自由曲面透镜对光束的偏折和聚散对光转向器件进行算法建模,采用迭代算法实现相位分布的计算,并使用线性化、离散傅里叶变换等方法提高算法速度。仿真结果表明,通过光转向调制,所提算法能够10倍地提高画面的最高亮度,实现10倍以上的动态范围提升。

Effects of Calcium Signal on the Negative Phototropism of Chorophytum comosum var.variegata Root

[Objective] The aim was to explore the effects of Ca2＋ on the negative phototropism of Chorophytum comosum root.[Method] C.comosum were cultivated in different concentration of CaCl2 solution with unilateral light illuminated.[Rusult] The Ca2＋ in nutrient solution showed significant effect on the growth and tropic reaction of C.comosum;low concentration of Ca2＋ promoted root growth,while high concentrations of Ca2＋ inhibited the root growth.When the concentration of Ca2＋ was 0.4 mmol/L,the phenomenon of the negative phototropism and the root growth were the most obvious.[Conclusion] The root negative phototropism could be concluded to the comprehensive effect of the endogenous and exogenous Ca2＋.

Formation of BiOI/g-C_3N_4 nanosheet composites with high visible-light-driven photocatalytic activity

Constructing binary heterojunctions is an important strategy to improve the photocatalytic performance of graphitic carbon nitride(g‐C3N4).In this paper,a novel g‐C3N4 nanosheet‐based composite was constructed via in situ growth of bismuth oxyiodide(BiOI)nanoplates on the surface of g‐C3N4 nanosheets.The crystal phase,microstructure,optical absorption and textural properties of the synthesized photocatalysts were analyzed by X‐ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),ultraviolet‐visible(UV‐vis)diffuse reflectance spectroscopy(DRS),and nitrogen adsorption‐desorption isotherm measurements.The BiOI/g‐C3N4 nanosheet composite showed high activity and recyclability for the photodegradation of the target pollutant rhodamine B(RhB).The conversion of RhB(20 mg L?1)by the photocatalyst was nearly 100%after 50 min under visible‐light irradiation.The high photoactivity of the BiOI/g‐C3N4 nanosheet composite can be attributed to the enhanced visible‐light absorption of the g‐C3N4 nanosheets sensitized by BiOI nanoplates as well as the high charge separation efficiency obtained by the establishment of an internal electric field between the n‐type g‐C3N4 and p‐type BiOI.Based on the characterization and experimental results,a double‐transfer mechanism of the photoinduced electrons in the BiOI/g‐C3N4 nanosheet composite was proposed to explain its activity.This work represents a new strategy to understand and realize the design and synthesis of g‐C3N4 nanosheet‐based heterojunctions that display highly efficient charge separation and transfer.

Calibration of laser beam direction based on monocular vision

In the laser displacement sensors measurement system,the laser beam direction is an important parameter.Particularly,the azimuth and pitch angles are the most important parameters to a laser beam.In this paper,based on monocular vision,a laser beam direction measurement method is proposed.First,place the charge coupled device(CCD)camera above the base plane,and adjust and fix the camera position so that the optical axis is nearly perpendicular to the base plane.The monocular vision localization model is established by using circular aperture calibration board.Then the laser beam generating device is placed and maintained on the base plane at fixed position.At the same time a special target block is placed on the base plane so that the laser beam can project to the special target and form a laser spot.The CCD camera placed above the base plane can acquire the laser spot and the image of the target block clearly,so the two-dimensional(2D)image coordinate of the centroid of the laser spot can be extracted by correlation algorithm.The target is moved at an equal distance along the laser beam direction,and the spots and target images of each moving under the current position are collected by the CCD camera.By using the relevant transformation formula and combining the intrinsic parameters of the target block,the2D coordinates of the gravity center of the spot are converted to the three-dimensional(3D)coordinate in the base plane.Because of the moving of the target,the3D coordinates of the gravity center of the laser spot at different positions are obtained,and these3D coordinates are synthesized into a space straight line to represent the laser beam to be measured.In the experiment,the target parameters are measured by high-precision instruments,and the calibration parameters of the camera are calibrated by a high-precision calibration board to establish the corresponding positioning model.The measurement accuracy is mainly guaranteed by the monocular vision positioning accuracy and the gravity center extraction accuracy.The experimental results show the maximum error of the angle between laser beams reaches to0.04°and the maximum error of beam pitch angle reaches to0.02°.

Control Schemes for Driving Electro-optic Array Beam Deflectors

The beam deflectors based on electro-optic phased array（EOPA） is mainly described, and then an analysis on existing control schemes for driving the EOPA beam deflectors, based on custom hard-wired electronics or based on software in a microcontroUer, is made. Compared with these, a driving and control system for a multi-channel EOPA beam deflector is presented, in which the control assignment is implemented with a field programmable gate array（FPGA） chip. For different performance requirements, two control schemes, one with the serial scheme and another with the parallel scheme, have been explored and rapidly prototyped in Xilinx FPGA chips. With the control structures for the EOPA beam deflector, scanning rates of 588 kHz and 5 MHz can be respectivelv reached.

Laser-induced forward transferred silver nanomembrane with controllable light absorption

Laser processing provides highly-controlled modification and on-demand fabrication of plasmon metal nanostructures for light absorption and photothermal convention.We present the laser-induced forward tansfer(LIFT)fabrication of silver nanomembranes in control of light absorption.By varying the hatch distance,different morphologies of randomly distributed plasmon silver nanostructures were produced,leading to well-controlled light absorption levels from 11%to 81%over broadband.The anti-reflection features were maintained below 17%.Equilibrated and plain absorptions were obtained throughout all absorption levels with a maximum intensity fluctuation of±8.5%for the 225μJ cases.The 45μJ pulse energy can offer a highly equilibrated absorption at a 60%absorption level with an intensity fluctuation of±1%.Pattern transfer was also achieved on a thin tape surface.The laser-transferred characters and patterns demonstrate a localized temperature rise.A rapid temperature rising of roughly 15℃can be achieved within 1 s.The LIFT process is highly efficiently fabricated with a typical speed value of 10^(3)to 10^(5)cm^(2)/h.The results indicated that LIFT is a well-controlled and efficient method for the production of optical films with specific absorption levels.

创新制度全面提升内审工作质量

山东光岳转向节总厂审计室积极的探索和创新，把企业的内审工作逐步纳入制度化、规范化、科学化的轨道，全面提升内审工作质量，取得了显著的经济效益。

Dielectric Behavior of Oblate Spheroidal Particles：Application to Erythrocytes Suspensions

We have investigated the pressure effect on the eletrorotation (ER) spectrum of living cell suspensions byconsidering the particle shape effect. In particular, we consider coated oblate spheroidal particles and present a theoreticalstudy of ER based on the spectral representation theory. Analytic expressions for the characteristic frequency as wellas the dispersion strength can be obtained, thus simplifying the fitting of experimental data on oblate spheroidal cellsthat abound in the literature. From the theoretical analysis, we find that the cellshape, coating as well as materialparameters can change the ER spectrum. We demonstrate a good agreement between our theoretical predictions andexperimental data on human erthrocytes suspensions.

Reversal of the Magnetic Nanofilms and Data Recording by Spin Current

The article presents the results of experimental studies of the physical mechanisms and magnetic switching dynamics of films with one or two magnetic nanolayers under an irradiation picosecond and femtosecond laser pulses and also the samples of data recording devices on the spin storage medium are described. The study used a film with perpendicular anisotropy （Tb22Co5Fe73/Pr6O11/Tb29Co5Fe76, Tb25Co5Fe70/Al2O3, Tb22Co5Fe73, Tb19Co5Fe76） and films planar single-axis magnetic anisotropy （Co80Fe20/Pr6O11/CO30Fe70）. The magnetic switching of magnetic layers under action the magnetic field of a spin current is the most important for practical use in elements of spintronic. The spin current can also be realized using short electrical pulses. On the basis of this mechanism, the high-speed recording of information on the spin carrier has been realized.

A novel orientation measurement using optical sensor for spherical motor

The measurement of spherical rotor orientation is crucial to the close-loop control of spherical motors. This paper presents a novel method for the measuring of three-degree-of-freedom (DOF) rotor orientation of spherical motors using optical sensors. The spatial orientation of spherical rotor is output in the form of ZXZ Euler angles. Firstly, the structure of the measuring system composed of optical sensors and the patterns on the rotor surface are presented, and the operational principle of recognizing intersection points between the optical ring detectors and the latitude/longitude on the rotor surface is illustrated. The analytical model of input-output characteristic is established for the measuring system of three-DOF rotor orientation. Afterwards, the effect of parameters of the optical ring detectors on the linearity, sensitivity, resolving power and measuring range of the measuring system is analyzed using the analytical model. Finally, the feasibility of the measurement is validated through experiments of prototype measuring system. The analysis is expected to be a basis for the design parameter optimization of the orientation measuring system of a PM spherical motor.

Dependence of femtosecond time-resolved magneto-optical Kerr rotation on the direction of polarization of the probe beam

We demonstrate that the femtosecond time-resolved magneto-optical Kerr rotation oscillates with the direction of polarization of the probe beam when a sample of Al0.25Ga0.75As/GaAs multi-quantum wells is excited by a circularly polarized pump and detected by a linearly polarized probe at wavelengths from 800 to 830 nm. Analytical expressions are derived to explain the mechanism, which is in good agreement with the numerical computation and the experimental data. The results suggest that the Kerr signal can be enhanced by choosing an optimal direction of polarization, which is of benefit to the measurement of the weak Kerr rotation.