基于ADAMS的LED分色分光机定位测试装置的研究

针对大功率LED全自动分色分光机的定位测试装置精度偏低的问题,根据弹性接触的应力理论,建立了测试装置的动力学模型,将3个输出方向上的复杂问题转化为等效的多自由度质量-弹簧-阻尼模型。从此模型出发,又采用多自由度系统振动理论,建立了输出随输入变化的运动微分方程。最后,在ADAMS中建立了虚拟样机模型,为了优化刚度和预载荷,分别基于GRG和SQP这两种优化算法进行了优化仿真分析,结果表明采用SQP算法时优化效果更加明显。

LED分色分光机定位测试装置运动学设计

针对目前国内一些大功率LED全自动分色分光机运行时存在的定位不准,抓料不畅以及大功率LED被抓取后,外壳经常出现损坏的问题,对其关键的机械定位测试装置进行机构的运动学设计,提出了组合凸轮机构的设计思路。通过建立凸轮机构运动学方程和基于Matable的计算求解,最终确定了该凸轮机构从动件的运动规律,并在实际机构的运行中取得了良好的效果。

LED分光机光强计测量数据正态性拟合检验

测量系统是LED分光机重要的组成部分,而光强计是测量部分不可缺少的部件。光强计测量的准确程度将对测量系统产生极大的影响,因此有必要对光强计测量数据进行分析。在处理试验数据时,必须先判定数据样本符合什么分布,简要介绍了应用数理统计的方法,对光强计测量LED的试验数据进行拟合,并根据采集到的实验数据进行计算分析。

浅谈七种常用而有效的LED光源分光分色技术

目前，人们对LED照明产品的品质要求越来越高。其中，LED照明产品的质量与LED光源的分光分色技术息息相关。下面，笔者就简单介绍一下七种常用的LED光源有效分光分色技术：

浅析LED分光分色对LED全彩显示屏的作用

本文研究旨在分析分光分色工艺，提供一些理论与建议，提升LED全彩显示屏产品品质。

分光光度测色仪中双光路d/0结构的改进

在分光光度测色仪的双光路d/0结构设计中,通常采用积分球内壁作为参考点来消除光源波动对仪器重复性产生的影响。但是在这种情况下,参考信号在一定程度上会受到测试样品的漫反射光的干扰,仪器的重复性和准确性也随之降低。本文设计了一种改进的d/0测量结构,采用LED复合光源作为测试光源,在参考光路设置单独的参考白壁,而不再将积分球内壁作为参考点,并建立实验进行验证。实验结果表明,改进的光路结构可以有效的消除被测试样品的漫反射光对参考光路信号的影响。

手持式分光测色仪设计

为了代替人眼对物体表面的颜色进行信息检测,设计了LED光源手持式分光测色仪。首先,通过计算不同测量波长分布和分辨率在标准光源照射下的三刺激值,比较它们的相对误差,选取了波长分布为400~700 nm、分辨率为10 nm作为光源的主要设计参数。接着,对照明光源进行研究,通过对卤钨灯、脉冲氙灯与LED光源的均匀色空间坐标进行对比,选取了LED光源作为仪器的照明光源。然后,讨论了不同照明和观测条件及人眼观测颜色的差异,选取以45°方向照明、0°方向接收作为照明和观测条件。最后,进行了照明系统设计和总体结构设计。实验结果表明,测色仪目标中心位置的最大光照强度为9.91×10-3 lm/mm 2,平均照度为7.06×10-3 lm/mm 2,基本满足了手持式分光测色仪精度较高、轻小型化、光照充足且均匀的设计要求。

高效液相色谱兼用紫外可见和荧光双分光双检测仪

摘要：本发明涉及一种结构创新、灵敏度和稳定性都优异的检测和分析仪器，特别是现有技术首创实现一机两用，即一台仪器中具有高效液相色谱最广泛使用的两种检测器，兼用紫外可见光检测器和荧光双单色分光检测器，现有技术除氙灯以外首次采用氘灯和卤钨灯作为荧光检测器单个发光灯源的光路、单个样品检测池和单套电气线路可提供两种检测器进行检测和分析。

一种改善全彩LED显示屏色差影响的方法

该文针对提高全彩LED显示屏的显示效果,提出了一种减小色差的解决办法。通过对人眼感知颜色的视觉原理及LED出现色度差异的原因分析,阐述了全彩LED显示屏出现区域性色差的成因,提出了一种解决色差问题的方法,并在实际生产中得以验证,为提高LED显示屏的显示效果提供了新的解决思路。

发光二极管光、色测试系统

为适应特殊照明用白光发光二极管(white light-emitting diode以下缩写为WLED)研制开发的需要,设计加工了Φ100mm的积分球,通过光纤与现有的荧光分光光度计测量单元耦合,构成LED光、色测试系统。该系统首先给出LED的相对光谱功率分布,据此计算出LED的总光通量等光、色参数。这种方法避免了用一般光度计测总光通量时必须进行色修正的麻烦,也避免了因色修正不充分所带来的较大误差。

Wide-Band Multi-spectral Space for Color Representation

This paper develops a wide-band multi-spectral space for color representationwith Aitken PCA algorithm. This novel mathematical space using the broad-band spectra matchingmethod aims at improving the accuracy of color representation as well as reducing costs forprocessing and storing multi-spectral images. The results show that the space can present ourexperimental original spectral spaces (i. e. Munsell color matt and DIN-6164 color chips) with highefficiency, and that the spanning space with three eigenvectors can present the original space atmore than 98% CSCR, and when 5 eigenvectors are used it can cover almost the whole o-riginal spaces.

Direct Optical Resolution of Chiral Pesticides by High Performance Liquid Chromatography

Enantiomer separation is one of the most important prerequisites for the investigation of environmental enantioselective behavior for chiral pesticides.The enantiomeric separation of three chiral pesticides,indoxacarb,lambda-cyhalothrin,and simeconazole,were studied on cellulose tris-(3,5-dimethylphenyl-carbamate)-coated chiral stationary phase(CDMPC-CSP) using high-performance liquid chromatography under normal phase condition.The effects of chromatographic conditions,such as the mobile phase composition including the concentration and type of alcohol modifiers in hexane,flow rate and column temperature,on enantiomer separation were examined.The thermodynamical mechanism of enantioseparation and chiral recognition mechanism were discussed.Better separation were achieved using 20% n-propanol for indoxacarb,2% iso-butanol for lambda-cyhalothrin,and 20% iso-propanol for simeconazole as modifiers in hexane at 25℃ with the selectivity factor(a) of 1.69,1.82 and 1.70,respectively.The resolution factor(Rs) decreased as the flow rate increased from 0.4 to 1.1 ml·min-1.The retention factor(k') and selectivity factor for the enantiomers of analytes decreased as temperature increased.The lna-1/T plots for racemic chiral pesticides were linear in the range of 15-35℃ in hexane/iso-propanol and the chiral separation was controlled by enthalpy.Hydrogen bonding,π-π and dipole-dipole interactions between enantiomers and CDMPC-CSP play an important role in chiral identification,and the fitting of the asymmetric portion of solutes in a chiral cavity or channel of the CSP is also important.

Enantiomeric separation of phenylsuccinic acid by cyclodextrin-modified reversed phase high-performance liquid chromatography

The chiral separation of phenylsuccinic acid(PSA)was studied by reversed phase high-performance liquid chromatography(RP-HPLC)with cyclodextrins(CDs)as chiral mobile phase additives.The effects of types of CDs,concentration of hydroxypropyl-β-cyclodextrin(HP-β-CD),percentage of organic modifier,pH value and column temperature on enantioselective separation were investigated.The quantification property of the developed RP-HPLC method was examined.The chiral recognition mechanism of PSA was also discussed.The results show that a baseline separation of PSA enantiomers is achieved on a Lichrospher C18 column(4.6 mm(inner diameter)×250 mm,5μm)with HP-β-CD as chiral mobile phase additive.The capacity factors of R-PSA and S-PSA are 3.94 and 4.80,respectively.The separation factor and resolution are respectively 1.22 and 8.03.The mobile phase is a mixture of acetonitrile and deionized water(20-80,volume ratio)containing 10 mmol/L HP-β-CD and 0.05% trifluoroacetic acid(pH 2.5,adjusted with triethylamine)with a flow rate of 1.0 mL/min.The ultraviolet(UV)detector is set at 254 nm.The likely roles are inclusion interaction,induction and hydrogen bonding between HP-β-CD and PSA enantiomers.

Separate Dimming Controlling and Data Transmission for an Indoor Visible Light Communication System

Simultaneous dimming controlling and data transmission are usually required in a white LED based indoor visible light communication system.However,the diming controlling of LED normally interferes the data transmission due to the modulation nonlinearity of LED.In order to solve this problem,a scheme by separating the LEDs for the functions of dimming control and data transmission respectively is proposed in this paper.In the scheme,the LEDs used for dimming control function are driven by a dc amplified circuit,and the LEDs for data transmission are driven by a digital modulation circuit respectively.In this way,the modulation distortion to the data signal caused by the modulation nonlinearity can be avoided even if the dimming is at high level dc driven current.The proof-of-concept experiment of a 2.5Mbit/s visible light communication system demonstrates that the dimming controlling and data transmission can be realized simultaneously in a simple way,and the data transmission is not affected by the dimming controlling function.Compared to previous methods,the scheme in this paper is simpler and cost effective,and makes sense when high rate data is transmitted in a visible light communication system.

Exact Solutions and Coherence Structures of Generalized Breor-Kaup Equations

Using the mapping method based on q-deformed hyperbolic functions,the exact solutions of generalizedBreor-Kaup equations are obtained.Based on the solutions,two coherent structures,periodic-branch kink and non-propagating kink,have been obtained.Moreover,one solitonal interaction form,two line solitons interaction on the kinkbackground,has been found.

Molecular Determinants Responsible for the Subcellular Localization of HSV-1 UL4 Protein

The function of the herpes simplex virus type 1 （HSV-1） UL4 protein is still elusive. Our objective is to investigate the subcellular transport mechanism of the UL4 protein. In this study, fluorescence microscopy was employed to investigate the subcellular localization of UL4 and characterize the transport mechanism in living cells. By constructing a series of deletion mutants fused with enhanced yellow fluorescent protein （EYFP）, the nuclear export signals （NES） of UL4 were for the first time mapped to amino acid residues 178 to 186. In addition, the N-terminal 19 amino acids are identified to be required for the granule-like cytoplasmic pattem of UL4. Furthermore, the UL4 protein was demonstrated to be exported to the cytoplasm through the NES in a chromosomal region maintenance 1 （CRM1）-dependent manner involving RanGTP hydrolysis

SUSY QCD Impact on Top-Pair Production Associated with a Z^0-Boson at a Photon-Photon Collider

The top-pair production in association with a Z^0-boson at a photon-photon collider is an important process in probing the coupling between top-quarks and vector boson and discovering the signature of possible new physics. We describe the impact of the complete supersymmetric QCD （SQCD） next-to-leading order （NLO） radiative corrections on this process at a polarized or unpolarized photon collider, and make a comparison between the effects of the SQCD and the standard model （SM） QCD. We investigate the dependence of the lowest-order （LO） and QCD NLO corrected cross sections in both the SM and minimal supersymmetric standard model （MSSM） on colliding energy √s in different polarized photon collision modes. The LO, SM NLO, and SQCD NLO corrected distributions of the invariant mass of tt^--pair and the transverse momenta of final Z^0-boson are presented. Our numerical results show that the pure SQCD effects in γγ →tt^- Z^0 process can be more significant in the ＋＋ polarized photon collision mode than in other collision modes, and the relative SQCD radiative correction in unpolarized photon collision mode varies from 32.09% to -1.89% when √s goes up from 500 GeV to 1.5 TeV.

Preparation of Organic Selenocystine Using Locally Isolated Bread Yeast

In contrast to the toxic inorganic forms of selenium to life at very low concentrations, the organic-selenium compounds are of considerable interest and several of them play essential roles in cell biochemistry and nutritional science. Se-yeast （Selenium-enriched yeast） is a common form of selenium used to supplement dietary intake of this important trace mineral. In the present study, we tried to prepare an organic selenocystine using locally isolated bread yeast （Saccharomyces cerevisiae）. A novel locally prepared date extract media enriched by addition of 0.2% KH2PO4 （potassium phosphate）, 0.6% ammonium sulfate was adopted as alternative culture media. Differences concentrations of selenium salt （30, 60, 120 and 240 lag/mL） were added to the yeast culture media. While the best concentration of selenium added was 30Bg/mL, it achieved optimal conditions for the growth of yeast and the production of red yeast growth identical to the standard. The products （organic selenocystine） were analyzed by HPLC （High Performance Liquid Chromatography） and AAS （Atomic Absorption Spectrophotometer） comparing with authentic standard obtained from Sigma. Results confirmed the formation of similar selenocystine products.

Luminescence properties of Eu^(2+) doped BaAl_2Si_2O_8 phosphor for white LEDs

The BaAl2Si2O8:Eu2+blue emitting phosphor was obtained through the one-step calcination process of precursors prepared bychemical co-precipitation method. The phase structure and luminescence propertied of the phosphor were investigated usingX-ray diffraction (XRD) and a fluorescence spectrophotometer. The excitation spectrum exhibited a broad band between 230nm and 400 nm and the emission peaking at about 470 nm was observed, which originated from the allowed f-d transition ofEu2+ions at Ba2+sites. Owing to the different optimal concentrations under different excitation wavelengths (254 nm and 365nm), the energy-transfer mechanism in this phosphor has changed from the dipole-dipole interaction to the exchange interac-tion of Eu2+ions.

Optimization and integration of LED array for uniform illumination distribution

A design method for light-emitting diode （LED） array is proposed to achieve a good uniform illumination distribution on target plane. By using random walk algorithm, the basic LED array modules are optimized ftrstly. The optimized basic arrays can generate uniform illumination distribution on their target plane. The optimized basic LED array mod- ules can be integrated into a large LED array module with more than tens of LEDs. In the large array, we can select a sub-array with K LEDs （K〉7）, which can produce the good uniform illumination distribution. By this way, we design two LED arrays which consist of 21 and 25 LEDs, respectively. The 21-LED array and 25-LED array can generate uniform illumination distributions with the uniformities of 95% and 90%, respectively.