一种热致变色调光玻璃的光学性能研究

热致变色调光玻璃可随温度的不同自动改变光线透射的比例。因温度对其光学性能的影响很大,目前尚未有完善的试验方法,也缺乏热致调光玻璃的可见光透射比、遮阳系数等供建筑节能设计选用的光学参数。从工程设计检测的需求出发,得到了热致调光玻璃光学性能的试验方法,以及热致变色调光玻璃在不同温度下的直射和散射光学性能。试验结果表明,热致调光玻璃对不同波长的光是选择性透过的,透射现象主要集中在波长为320~1420 nm可见光和一部分近红外光波段,其他波段透射比很低。温度越高,热致调光玻璃的可见光透射比、太阳光透射比和紫外线透射比都降低,雾度逐步增加。

鸡舍LED光色智能系统的设计与研究

为解决当前鸡舍内光色调控智能化和精准化较低的问题,设计了应用于鸡舍的光色可调控系统,提出了一种以常见芯片STC89C52单片机为微处理器,以节能高效的LED灯珠作为光色调控系统的发光源,以牛顿三原色光为基本原理的多色调光系统;系统可定时定量对不同生长期下肉鸡进行精确补光,系统设置时以秒为最小量度,自由设置光照时间阀值,并以PWN调光方式控制LED的电流来调控红、蓝、绿光的亮度,经试验验证,系统能精确发出红、蓝、绿等色光,进而调控产生黄、青、白等色光;利用SAS软件,对试验肉鸡增重数据进行处理,育雏期和生长期的鸡只,在波长为450~490NM的蓝光照射下增重明显,数据显著(P<0.05);该系统可满足鸡舍中肉鸡补光的精确需求,高效环保,可稳定实现节能化补光,解决了鸡舍内光照精准化较低的问题,对鸡舍数字化、智能化提供了新思路。

A High-Performance Silicon Electro-Optic Phase Modulator with a Triple MOS Capacitor

We propose and analyze a novel Si-based electro-optic modulator with an improved metal-oxide-semiconductor （MOS） capacitor configuration integrated into silicon-on-insulator （SOl）. Three gate-oxide layers embedded in the silicon waveguide constitute a triple MOS capacitor structure, which boosts the modulation efficiency compared with a single MOS capacitor. The simulation results demonstrate that the Vπ Lπ product is 2. 4V · cm. The rise time and fall time of the proposed device are calculated to be 80 and 40ps from the transient response curve, respectively,indicating a bandwidth of 8GHz. The phase shift efficiency and bandwidth can be enhanced by rib width scaling.

Low Dynamic Range Solutions to the High Dynamic Range Imaging Problem

While capturing a real world scene using a common digital camera, due to limitations of the sensor dynamic range, we will not be able to capture the entire dynamic range of the some. This problem is evident while capturing a picture of a some which has both brightly and poorly illuminated regions. High Dynamic Range （HDR） imaging aims to recover the entire dynamic range of the scene by compositing multi-exposure images. Tone reproduction is required for displaying HDR images as the corresponding Low Dynamic Range（LDR） images on common displays. This paper discusses novel approaches to reconstruct LDR images directly from multi-exposure images. It is assumed that there is no knowledge of camera response function and other camera settings. At last, it is explained how this task can be achieved effectively for static and dynamic scenes.

LED蓝牙灯驱动与控制电路设计

随着蓝牙通讯技术的不断成熟,蓝牙通讯技术已应用在很多电子产品中。目前,采用蓝牙通讯技术来控制照明灯的技术已在实用化,开始进入千家万户,由于LED灯无频闪、无眩光、光线柔和均匀、绿色环保,再加上蓝牙智能调光控制功能后,集趣味与照明于一体,越来越受消费者青睐。本文就基于CC2540芯片控制的智能蓝牙LED灯驱动与控制电路的设计,进行了系统的介绍。

Phase Modulation Characteristics of Spatial Light Modulator and the System for Its Calibration

The phase modulation characteristics of liquid crystal SLM （spatial light modulator） and the system for calibrating are proposed. Michelson interferometer is employed for measuring the modulation properties of device. A system interface for operating SLM is designed with VC＋＋ compiler. The initial distortion phase is determined by measuring the reflective interference, and modulation of device is compensated by using our system. By using the LUT （lookup table） data provided by manufacture the wavelength disperse calibration is also achieved successfully.

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.

Spectral anomalies and spectral switches of partially coherent and polychromatic light diffracted at an aperture

Based on the propagation theory of partially coherent light in the space-frequency domain, the anomalous spectral behavior and spectral switches in the far field of partially coherent and polychromatic light diffracted at an aperture are studied. It is shown that, as compared with spatially fully coherent and polychromatic light whose spectral anomalies are induced only by aperture diffraction, the spectral anomalies and spectral switches of partially coherent and polychromatic light depend on the aperture diffraction, spatial correlationβ and bandwidth of the original spectrum. Detailed numerical calculations are made to illustrate the behavior of spectral switches of partially coherent and polychromatic light, and the results for spatially fully coherent and polychromatic light are treated as a special case ofβ=1 and included in our theory.

Color tuning of Eu-Tb co-doped borophosphate glasses for white light through valence state adjustment

The dependence of color points of white light on the composition of bomphosphate glasses co-doped with europium （En） and terbium （Tb） has been investigated in terms of valence change of rare earth ions. Under ultraviolet （UV） excitation, the white light is observed to be from a combination of 4f65d → 4f7 band transition emission at 425 nm for Eu^2＋, 5D0 → ^7Fj （J= 1, 2） lineemissions at 593 nm and 611 nm for Eu^3＋, and 5D4 → 7F5 band transition emission at 545 nm for Tb^3＋. By varying the glass composition, the resultant emission color can be tuned efficiently. Eventually, the optimized white light with commission international de I＇Eclairage （CIE） coordinate of （0.3382. 0.2763） and the correlate color temperature （CCT） at 5010 K are achieved.

Synthesis and electronic properties of expanded 5-(hetero)arylthien-2-yl substituted 3-ethynyl quinoxalines with AIE characteristics

Expanded 5-(hetero)aryl-thien-2-yl substituted 3-ethynyl quinoxaline dyes with variable substitution pattern on the peripheral thiophene ring were synthesized in moderate to very good yields by Suzuki and Buchwald-Hartwig coupling of the corresponding brominated 3-ethynyl quinoxalines. Dumbbell-shaped bis(thienyl 3-ethynyl quinoxalines) are also accessible by the Suzuki protocol. The photophysical properties were investigated by UV and fluorescence spectroscopy. Most of the obtained compounds display fluorescence in solution and some of them also in the solid state. Additionally, tuning of the emission color of the quinoxaline based chromophores can be conveniently accomplished by the remote substituent group. The determined absorption and emission maximum as well as the Stokes shifts strongly correlate with Hammett σp+parameters. Besides,photophysical properties of selected derivatives in the solid state, biphasic solutions, and PMMA films, along with their relationships, are comparatively investigated. Moreover, two 5-(hetero)aryl-thien-2-yl substituted 3-ethynyl quinoxaline dyes are aggregation induced emission(AIE) chromophores indicated by restriction of molecular motions. A covalently restricted 3-ethynyl quinoxaline supports that the inhibition of molecular rotation is responsible for the significant enhancement of fluorescence in acetonitrile/water mixtures.

Color-tunable Gd-Zn-Cu-ln-S/ZnS quantum dots for dual modality magnetic resonance and fluorescence imaging

Inorganic nanoparticles have been introduced into biological systems as useful probes for in vitro diagnosis and in vivo imaging, due to their relatively small size and exceptional physical and chemical properties. A new kind of color- tunable Gd-Zn-Cu-In-S/ZnS （GZCIS/ZnS） quantum dots （QDs） with stable crystal structure has been successfully synthesized and utilized for magnetic resonance （MR） and fluorescence dual modality imaging. This strategy allows successful fabrication of GZCIS/ZnS QDs by incorporating Gd into ZCIS/ZnS QDs to achieve great MR enhancement without compromising the fluorescence properties of the initial ZCIS/ZnS QDs. The as-prepared GZCIS/ZnS QDs show high T1 MR contrast as well as ＂color-tunable＂ photoluminescence （PL） in the range of 550-725 nm by adjusting the Zn/Cu feeding ratio with high PL quantum yield （QY）. The GZCIS/ZnS QDs were transferred into water via a bovine serum albumin （BSA） coating strategy. The resulting Cd-free GZCIS/ZnS QDs reveal negligible cytotoxicity on both HeLa and A549 cells. Both fluorescence and MR imaging studies were successfully performed in vitro and in vivo. The results demonstrated that GZCIS/ZnS QDs could be a dual-modal contrast agent to simultaneously produce strong MR contrast enhancement as well as fluorescence emission for in vivo imaging.

A spectrum-adjusted white organic light-emitting diode for the optimization of luminous efficiency and color rendering index

High luminous efficiency and high color rendering index(CRI) are both the foremost factors for white organic lightemitting diodes(WOLEDs) to serve as next generation solid-state lighting sources. In this paper, we show that both luminous efficiency and CRI can be improved by adjusting the green/red spectra of WOLEDs. With green emission spectra matching with the human photopic curve, the WOLEDs exhibit higher luminous efficiency and higher CRI. Theoretical calculation shows that by tuning the white emission spectra to maximally match with the human photopic curve, the luminous efficiency can be improved by 41.8% without altering the color coordinates, the color correlated temperature(CCT) and the external quantum efficiency(EQE) of the WOLEDs.

Luminescence properties of tunable red-green emitting phosphor Ba2Ca(BO3)2：Eu3＋,Tb3＋

A series of Eu^(3+) or Tb^(3+) doped Ba_2Ca(BO_3)_2 phosphors were synthesized by a high temperature solid state method, and the luminescence properties are investigated. Ba_2Ca(BO_3)_2:Tb^(3+) can show an obvious green emission, and the peak locates at 551 nm, which corresponds to the 5D34→7F5 transition of Tb^(3+). Ba_2Ca(BO_3)_2:Eu+ can present the characteristic emission of Eu^(3+), and the peak locates at 600 nm, which is ascribed to the 5D70→F2 transition of Eu^(3+). In order to achieve the emission-tunable phosphors, the Eu^(3+)/Tb^(3+) co-doped Ba_2Ca(BO_3)_2 are synthesized. When tuning the Eu^(3+) or Tb^(3+) concentration, Ba_2Ca(BO_3)_2:Eu^(3+), Tb^(3+) can both show the tunable emission, which may be induced by the energy transfer from Tb^(3+) to Eu^(3+).

The sulfur metabolism regulator MetR is a global regulator controlling phytochrome-dependent light responses in Aspergillus nidulans

Phytochrome-dependent light signaling has been studied in several fungi.In Aspergillus nidulans lightstimulated phytochrome activates the high-osmolarity glycerol(HOG)signaling pathway and thereby controls the expression of a large number of genes,many of which are related to stress responses.In a genome-wide expression analysis in A.nidulans we found that phytochrome,fph A,is under strict expression control of the central regulator of the sulfur-starvation response,Met R.This transcriptional regulator is required for the expression of genes involved in inorganic sulfur assimilation.In the presence of organic sulfur,Met R is probably ubiquitinated and possibly degraded and the transcription of sulfur-assimilation genes,e.g.,sulfate permease,is turned off.The expression analysis described here revealed,however,that Met R additionally controls the expression of hundreds of genes,many of which are required for secondary metabolite production.We also show that met R mutation phenocopies fph A deletion,and five other histidine-hybrid kinases are down-regulated in the met R1 mutant.Furthermore,we found that light and phytochrome regulate the expression of at least three carbon–sulfur hydrolases.This work is a further step towards understanding the interplay between light sensing and metabolic pathways.

A novel chromatic dispersion monitoring method for 1 024 QAM fiber-optic system based on asynchronous amplitude sampling

A new chromatic dispersion(CD) monitoring method is proposed, and the CD monitoring is achieved on the whole range of 0—600 ps/nm. A dual-polarization(DP)-1 024 quadrature amplitude modulation(QAM) 400 Gbit/s CD monitoring system is built using OptiS ystem14.0 software. With different optical signal to noise ratio(OSNR) values, different filter bandwidths or different duty cycles, the simulations are carried out. The simulation results show that this new CD monitoring method can be less affected by noise and has a high tolerance for different filter bandwidths. At the same time, this method can do effective CD monitoring on the signal with duty cycle greater than 80%. A high sensitivity in 0—200 ps/nm can be achieved using this CD monitoring method. The technique supports a wide range of data traffic and enhances operation flexibility of optical networks.

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