共查询到12条相似文献,搜索用时 46 毫秒
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为研究变角度百叶窗结构对平行流蒸发器换热性能的影响,文中建立了一种均匀角度百叶窗和两种变角度百叶窗的计算模型;采用fluent软件数值模拟了空气侧的传热和流动过程,得到了百叶窗翅片的速度场、温度场及压力场;将数值模拟结果与相关文献实验关联式结果进行对比,验证了数值模拟的可行性,分析了迎面风速对换热和压降特性的影响;并利用公式j/f1/3,比较了三种翅片的综合性能,发现变角度百叶窗翅片综合性能优于均匀角度百叶窗翅片。 相似文献
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Efficient top-emitting white organic light emitting device with an extremely stable chromaticity and viewing-angle 下载免费PDF全文
In this paper,we report on the fabrication of a top-emitting electrophosphorescent p-i-n white organic lightemitting diode on the basis of a low-reflectivity Sm/Ag semi-transparent cathode together with a thickness-optimized ZnS out-coupling layer.With a 24-nm out-coupling layer,the reflectivity of the cathode is reduced to 8% at 492 nm and the mean reflectivity is 24% in the visible area.By introducing an efficient electron blocking layer tris(1phenylpyrazolato,N,C2 ’)iridium(III)(Ir(ppz) 3) to confine the exciton recombination area,the current efficiency and the colour stability of the device are effectively improved.A white emission with the Ir(ppz) 3 layer exhibits a maximum current efficiency of 9.8 cd/A at 8 V,and the Commission Internationale de L’Eclairage(CIE) chromaticity coordinates are almost constant during a large voltage change of 6 V-11 V.There is almost no viewing angular dependence in the spectrum when the viewing angle is no more than 45,with a CIE x,y coordinate variation of only(±0.0025,±0.0008).Even at a large viewing angle(75),the CIE x,y coordinate change is as small as(±0.0087,±0.0013). 相似文献
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Wei Huang Jie-Min Li Li-Mei Yang Zhong-Liang Jin Zheng-Gen Zhong Yu Liu Qin-Ying Chou Feng Li 《Optics & Laser Technology》2011,43(1):214-217
A 32 in RGB LED backlight unit is developed. A local dimming algorithm is designed for the backlight, and grid-noise artifacts in the LC driving signal are successfully removed with consideration of the backlight distribution to provide identical intensity from each LED block. The 32 in RGB LED backlight LCD display has achieved a static display contrast of over 20000:1 and an average power reduction of 30%. We have also obtained the color gamut transformation matrix for transferring a cold cathode fluorescent lamp BLU LCD display gamut system to our RGB LED BLU LCD display gamut system, and extended the color saturation by suppositional color expansion method. As a result, the color has been accurately reproduced in RGB LED BLU LCD display with more richness and more saturation. 相似文献
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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)。本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。 相似文献
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Naresh C. Das 《Infrared Physics & Technology》2010,53(1):71-75
The electroluminescence in the range of 3–4.5 μm and 6–10 μm from a Sb-based type II interband quantum cascade structure is reported. We measured the light emission from the top surface of the LED device with different grating structures. We used different etch depths for the grating formation. The light–current–voltage (LIV) characteristics measured at both room and cryogenic temperatures show that the device with 45° angle grating and 1.0 μm deep etch onto the GaSb surface has the highest emission power. 相似文献
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准直光管角度分划示值校准方法研究 总被引:1,自引:0,他引:1
准直光管角度分划示值一般用来校准小角度光学仪器,在靶场试验中主要用于校准校靶镜、瞄准镜等火炮瞄准仪器,其示值需要定期进行校准和溯源。提出了采用经纬仪对准直光管角度分划示值误差进行校准溯源的方法,建立了测量模型,进行了测量实验和不确定度分析评定。结果表明,该方法满足量值溯源和传递要求。 相似文献