High quantum efficiency long-/long-wave dual-color type-Ⅱ InAs/GaSb infrared detector

A long-/long-wave dual-color detector with N-M-π-B-π-M-N structure was developed based on a type-Ⅱ InAs/GaSb superlattice. The saturated responsivity was achieved under low bias voltage for both channels. The device could be operated as a single detector for sequential detection and showed high quantum efficiencies. The peak quantum efficiencies of long-wavelength infrared band-1(blue channel) and long-wavelength infrared band-2(red channel) were 44% at 6.3 μm under 20 mV and 57% at 9.1 μm under-60 mV, respectively. The optical performance for each channel was achieved using a 2 μm thickness absorber. Due to the high QE, the specific detectivities of the blue and red channels reached5.0×10^(11) cm·Hz^(1/2)/W at 6.8 μm and 3.1×10^(11) cm·Hz1^(1/2)/W at 9.1 μm, respectively, at 77 K.

Effect of Nanorod Diameters on Optical Properties of GaN-Based Dual-Color Nanorod Arrays

Dual-color(blue and green) InGaN/GaN nanorod light-emitting diodes(LEDs) with three different nanorod diameters are fabricated. Enhancement of luminescence intensity per area is observed in blue and green wells,to varying degrees. When the diameter is 40 nm, it sharply decreases, which could be explained by the sidewall nonradiative recombination. Time-resolved photoluminescence is conducted to study the carrier lifetime. High recombination rate is observed in nanorod arrays, and is an order of magnitude less than that of the planar LED.When the diameter is 40 nm, the nonradiative lifetime decreases, and this explains the decrease of intensity. The3 D-FDTD simulations show the enhancement of light extraction out of geometry structure by calculating the transmittance of the nanorod arrays.

Fusion of clathrin and caveolae endocytic vesicles revealed by line-switching dual-color STED microscopy

Clathrin-and caveolae-mediated endocytosis are the most commonly used pathways for the internalization of cell membrane receptors.However,due to their dimensions are within the diffraction limit,traditional fluorescence microscopy cannot distinguish them and little is known about their interactions underneath cell membrane.In this study,we proposed the line-switching scanning imaging mode for dual-color triplet-state relaxation(T-Rex)stimulated emission depletion(STED)super-resolution microscopy.With this line-switching mode,the cross-talk between the two channels,the side effects from pulse picker and image drift in frame scanning mode can be effectively eliminated.The dual-color super-resolution imaging results in mixed fluorescent beads validated the excellent performance.With this super-resolution microscope,not only the ring-shaped structure of clathrin and caveolae endocytic vesicles,but also their semi-fused structures underneath the cell membrane were distinguished clearly.The resultant infor-mation will greatly facilitate the study of clathrin-and caveolae-mediated receptor endocytosis and signaling process and also our home-built dual-color T-Rex STED microscope with this line-switching imaging mode provides a precise and convenient way to study subcellular-scale protein interactions.

Field-free molecular orientation induced by combined femtosecond single-and dual-color laser pulses: The role of delay time and quantum interference

The coherent control of field-free molecular orientation of CO with combined femtosecond single- and dual-color laser pulses has been theoretically studied. The effect of the delay time between the femtosecond single- and dual-color laser pulses is discussed, and the physical mechanism of the enhancement of molecular orientation with pre-alignment of the molecule is investigated. It is found that the basic mechanism is based on the creation of a rotational wave packet by the femtosecond single-color laser pulse. Furthermore, we investigate the interference between multiple rotational excitation pathways following pre-alignment with femtosecond single-color laser pulse. It is shown that such interference can lead to an enhancement of the orientation of CO molecule by a factor of 1.6.

1280×1024元InAs/GaSb II类超晶格中/中波双色红外焦平面探测器

本文报道了1280×1024元InAs/GaSb II类超晶格中/中波双色红外焦平面阵列探测器的研究结果。探测器采用PN-NP叠层双色外延结构,信号提取采用叠层双色结构和顺序读出方式。运用分子束外延技术在GaSb衬底上生长超晶格材料,双波段红外吸收区的超晶格周期结构分别为中波1:6 ML InAs/7 ML GaSb和中波2:9 ML InAs/7 ML GaSb。焦平面阵列像元中心距为12μm。在80 K时测试,器件双波段的工作谱段为中波1:3~4μm,中波2:3.8~5.2μm。中波1器件平均峰值探测率达到6.32×10^(11) cm·Hz^(1/2)W^(-1),中波2器件平均峰值探测率达到2.84×10^(11) cm·Hz^(1/2)W^(-1)。红外焦平面偏压调节成像测试得到清晰的双波段成像。本文是国内首次报道1280×1024规模InAs/GaSb II类超晶格中/中波双色红外焦平面探测器。

汽车激光雷达盖板的双色注塑模具设计

根据某车型激光雷达盖板的双色结构及形状,采用动模型芯旋转式结构的模具方案,设计了一套一出二的热流道双色注塑模具。利用Moldflow软件进行了双色成型分析,双色注塑第一次注射成型透明的PMMA材料的产品,第二次注射成型黑色ASA材料的产品。为实现该双色产品的结构成型,在定模处设计了2组不同结构的型腔,在动模处设计了2组左右对称的型芯,并且,在型芯侧设计了双斜导柱抽芯机构,冷却系统设计为“直通式+隔水片”的随形循环水路;顶出系统设计为2组独立的液压油缸,在产品顶出取件中,第一次注射成型的PMMA产品不顶出,第二次注射成型的ASA材料的产品采用“直顶+斜顶”的组合机构将双色产品推出,最终通过机械手完成产品的取件。实践生产证明了该双色模具结构合理、运行稳定、成型的双色塑件表面无缺陷。

汽车空调控制面板双色倒装热流道注射模设计

汽车空调控制面板作为人机交互界面不可或缺的操作零件,设计时为了集成使用功能和外观美感等多重要求,一般设计为双色注塑件。以某汽车内饰空调控制面板为例,设计了一副双色倒装热流道注塑模,并详细介绍了零件结构特征、模具结构设计方案及工作原理。由于零件结构特殊性和注塑材料成型温度差异,塑件在成型过程中采用传统正置成型方案时表面易出现串色、印痕等缺陷,成型良品率较低,故模具采用倒装结构设计方案,即第一色先成型茶色透明的聚碳酸酯(PC)外观部分,再成型第二色黑色的PC/丙烯腈-丁二烯-苯乙烯塑料(ABS)基体部分。基于模具的倒装结构,其第一、二色均采用热流道系统进料,同时为了确保零件顺利生产、顶出顺畅,在第一色子模内设置拉料柱和预压型推出机构,第二色子模具的定模侧设计了斜顶和顶针联合顶出机构,利用油缸驱动实现塑件脱模。实验证明,该倒装双色热流道注塑模整体结构稳定可靠,塑件批量生产质量满足设计要求。

基于X射线双光谱的物质识别方法研究

针对工业生产、材料科学和安检等领域对于物质的检测需求,开展了基于X射线双光谱的物质识别方法研究。提出了针对不同物质的双光谱识别算法模型,模型引入边界物质界定与伪彩色算法,实现了对物质种类的识别。搭建X射线双光谱透射实验系统,实测了复杂背景、多种物体的X射线双光谱图像,研究了物质界定算法与伪彩色算法对于物质种类识别的影响。基于此优化了算法模型,实现了灵活、快速地对物质种类的识别,对于工业生产物质分类和安检快速筛查具有重要意义。

双重预防机制建设背景下的安全风险告知研究与实践

为有效解决企业开展双重预防机制建设过程中存在的安全风险告知内容不规范、不统一、警示标识张贴无序等问题,采用对标分析及标准量化的方法,将风险四色图与现场安全风险告知要素进行集成,提出安全风险告知集成图模式;以某企业为例,开展安全风险告知实践。结果表明:该模式规范了现场安全风险告知管理,极大提升了企业现场安全风险告知的合规性。

基于双参考优化的壁画图像色彩还原

褪变色壁画图像的色彩还原研究可以促进壁画的保护和展示。壁画图像色彩还原旨在将退化壁画图像的色彩褪变区域还原为原有色彩。常规的基于单幅参考壁画图像的色彩还原方法难以选取与退化壁画图像相似的参考壁画图像,进而影响色彩还原质量。为此,提出一种基于双参考优化的壁画图像色彩还原方法。采用双参考策略,即使用2幅参考壁画图像对退化壁画图像进行色彩还原,利用图像优化模块抑制褪变色壁画图像中普遍存在的噪声、划痕等多重退化,通过编码器-解码器网络编码提取壁画图像多尺度特征,并构建特征融合模块优化壁画图像的多尺度特征。采用双参考指导模块计算参考壁画图像与退化壁画图像的语义对应置信度,以实现图像区域间的相似性匹配,并实现2幅参考壁画图像的风格融合。在此基础上,利用融合特征实现退化壁画图像的色彩还原。实验结果表明,该方法可以较准确地还原退化壁画图像色彩,同时能较好保持壁画图像原有的边缘结构信息,并且使用无参考图像质量评估指标对各个方法的还原壁画图像进行客观评估,与对比方法相比,该方法在客观评估指标上最多可降低12.2%。

Gram-scale synthesis of all-inorganic perovskite quantum dots with high Mn substitution ratio and enhanced dual-color emission

Mn-doped all-inorganic perovskite quantum dots (QDs) provide prominent applications in the fields of low-cost light source or display,because of their remarkable properties including dual-color emission and reduced lead content,as well as high photoluminescence quantum yields (PLQYs) and high stability.However,the existing synthesis approaches usually require hash conditions,such as high temperature and nitrogen protection,which is a major hurdler for the practical manufacturing.In addition,the significantly high Mn substitution ratio in CsPbX3 QDs is still challenging.The real dual-color emission with two strong emission peaks in the Mn-doped all-inorganic perovskite QDs has attracted great interest.Here we present a gram-scale approach to synthesize both CsPbxMn1-xCI3 and CsPb1-xMnxClyBr3-y QDs at 100 ℃ in the air with high Mn substitution ratio,up to 55.64% atomically.The as-prepared CsPb1-xMnxClyBr3-y QDs exhibit high PLQYs of 62.41% and dual-color emission with two strong emission peaks around at 400-450 nm and 600 nm,respectively.The enhanced peak at 400-450 nm is a result of the hybrid halides in CsPbBrxCl3-x host.Furthermore,the unique advantage of the optical emission and high PLQYs properties of the CsPbxMn1-xCl3 QDs has been demonstrated as invisible ink for encryption applications and polymer composites.Our gram-scale synthesis approach for Mn-doped all-inorganic perovskite QDs may boost the future research and practical applications of QDs-based white LED,spintronics,and molecular barcoding.

面向全色域转杯纺纱的Kubelka-Munk双常数理论模型构建及颜色预测

为了能在色纺纱的纺纱阶段即时调控纱线颜色,减少混色成本,缩短工艺流程,结合三通道数控转杯纺纱的特点构建了全色域网格化混色模型,该模型可在纺纱过程中进行全色域范围内的色相调控、明度调控和彩度调控。为了解决色纺纱的测配色问题,得到与之相匹配的测配色系统,根据来样快速进行计算机测配色,节约成本,结合传统Kubelka-Munk双常数理论模型的特点,从构建的全色域网格化混色模型中选取混合样来进行颜色预测。从传统Kubelka-Munk双常数理论模型颜色预测的结果发现,部分混合样的预测反射率明显低于实际的反射率,针对这个问题,重新构建了新的Kubelka-Munk双常数理论模型来进行颜色预测得到新的预测反射率,并用插值替换的方法,把传统Kubelka-Munk双常数理论模型预测结果中明显低于实际反射率的部分用新的预测反射率替换,得到最终的混合样预测反射率。结果表明:与传统的Kubelka-Munk双常数理论模型预测混合样颜色结果相比,新的Kubelka-Munk双常数理论模型预测颜色并用插值替换法替换后得到的最终的混合样的颜色,色差平均值从1.48降低到1.04,且所有混合样的色差均能控制在2.0以内。该预测方法较传统Kubelka-Munk双常数理论模型具有更好的预测精度,所构建的全色域网格化混色模型和新的Kubelka-Munk双常数理论模型可应用于多基色纤维混色色彩和混合比的预测。

Ultraviolet-infrared dual-color photodetector based on vertical GaN nanowire array and graphene

A monolithic integrated ultraviolet-infrared(UV-IR) dual-color photodetector based on graphene/GaN heterojunction was fabricated by vertically integrating a GaN nanowire array on a silicon substrate with monolayer graphene. The device detects UV and IR lights by different mechanisms. The UV detection is accomplished by the forbidden band absorption of GaN, and the IR detection is realized by the free electron absorption of graphene. At peak wavelengths of 360 nm and 1540 nm, the detector has responsivities up to 6.93 A/W and 0.11 A/W, detection efficiencies of 1.23 × 1012 cm·Hz1/2·W-1 and 1.88 × 1010 cm·Hz1/2·W-1, respectively,and a short response time of less than 3 ms.

基于双参考帧的多源着色结果融合的视频着色方法

对黑白视频着色时,为了更好地利用参考帧信息,提出一种基于双参考帧的多源着色结果融合的着色方法.首先,采用硬注意力融合子模块融合双参考帧提供的颜色信息,以防止双帧语义匹配模块着色时不合理参考信息导致的颜色模糊问题.然后,使用多源着色结果融合模块融合通过双帧光流传播模块、双帧语义匹配模块以及遮挡信息得到的着色结果,进而产生更优质的着色结果.实验结果表明,该方法在Davis30测试集上的峰值信噪比(PSNR)、结构相似性(SSIM)和颜色分布一致性指数(CDC)分别为37.36 dB、0.980 5、0.003 748,说明该方法能够通过多种融合方式充分利用双参考帧的信息为灰度帧着色,并生成美观且具有较好时间一致性的着色结果.

Silicon carbide and graphene based UV-IR dual-color detector

An ultraviolet-infrared dual-color detector is proposed and realized based on the vertical integration of single-layer graphene and a 4 H-SiC layer by semiconductor micro-fabrication technology. The spectral response characteristics of the detector are analyzed. The ultraviolet response range is 208—356 nm with a responsivity larger than 0.4 mA/W and the infrared response range is 1.016—1.17 μm with a responsivity larger than 0.4 mA/W at room temperature and 5 V bias voltage. The peak responsivity of the graphene in the ultraviolet-C band at 232 nm is 0.73 mA/W and in the near infrared band at 1.148 μm is 0.64 mA/W. The peak responsivity of SiC layer in the ultraviolet-B band at 312 nm is 2.27 mA/W. Besides, the responsivity increases with the bias voltage.

基于颜色校正和暗亮双通道先验的水下图像增强算法

在水下成像过程中,光源是影响图像质量的关键因素之一,由于光的散射和吸收,导致水下图像存在颜色失真,对比度和可见度低等诸多问题。这些质量下降的水下图像不利于分析和利用。针对上述问题,本文提出了一种基于颜色校正和暗亮双通道先验的水下图像增强算法。首先提出一种基于标准差比的颜色补偿算法,有效解决颜色失真问题。然后,一方面利用锐化来增强图像的细节和边缘,得到对比度增强图像。另一方面,提出了一种基于通道差异加权的暗亮双通道算法去除图像模糊,得到可见度恢复的图像。最后,采用多尺度融合方法将对比度增强图像和可见度恢复图像进行融合。实验结果表明,与其他水下图像增强算法进行定性和定量评价比较,本文算法能够有效消除颜色偏差、恢复图像的清晰度,同时在Undewater Color Image Quality Evaluation(UCIQE)、Underwater Image Quality Measurement(UIQM)和Information Entropy(IE)参数指标上均有较大提高。

医用电子检测仪支架双色成型模具设计

设计了1副双色注塑模具用于某医用电子检测仪支架双色塑件的成型。依据塑件不同材料不同颜色的生产要求,第一射基础件选用聚碳酸酯(PC)成型,第二射插片体选用PC/丙烯腈-丁二烯-苯乙烯塑料(ABS)成型,第二射材料熔体温度比第一射材料低35℃,确保第二射成型能顺利进行。在分别制定了第一射、第二射成型工艺的基础上,设计了塑件成型的双色模具,双色模具采用旋转式结构,由两副子模具构成,两副子模具都采用两板式模具,浇注系统都采用冷流道+热嘴形式。针对有滑块机构的双色模具在第二射成型时易产生飞边问题,设计了一种双色模具三角截面斜导柱第一射免抽芯滑块机构,在该机构中,通过将常用圆柱形斜导柱改进为三角截面斜导柱、增设弹销,以及将斜导柱孔改进为“U形槽”等措施,使第一射成型时侧抽芯滑块免于侧抽芯,从而确保了第二射子模具模腔封闭的严密性,将塑件的成型品质合格率提高到99%以上。

Donor-conformation-dependent energy transfer for dual-color fluorescent probe with high-resolution imaging

Herein,we presented a brand-new concept to construct the Forster resonance energy transfer(FRET)based cassette by integrating a vibration-induced emission(VIE)chromophore as the donor.Different from traditional donors only with a single emission,the VIE donor possessed well-separated dual emission bands by altering the excited state molecular configuration from the bent state to the planar state.By linking an acceptor such as a cyanine dye(Cy5),a novel VIE-FRET cassette(PPCy5)was prepared.The planar emission profile of the VIE donor moiety could fully cover the absorption of Cy5,and thus the complete FRET process enabled the excellent bimodal spectra difference of 142 nm and ultra-large pseudo-Stokes shift of up to 300 nm.Benefiting from the viscosity-dependent characteristic of the VIE donor,PPCy5 could clearly and intuitively reveal the different viscosity regions in vivo by dual-color and high-resolution imaging.The VIE-FRET paradigm provides an optional platform for developing donor-acceptor-based dual-color fluorescent probes with high-resolution imaging ability.

A TICS-fluorophore based probe for dual-color GSH imaging

Cascading reactions in fluorophores accompanied by the replacement of different fluorescence wavelengths can be used to develop luminescent materials and reactive fluorescent probes.Based on multiple signal channels,the selectivity of probes can be improved and the range of response to guest molecule recognition can be expanded.By regulating the position,number,and activity of active sites in fluorophores,fluorescent probes that successively react with thiol and amino groups in cysteine(Cys),homocysteine(Hcy)have been developed,which can only react with the thiol group of GSH,In this paper,we report the first probe capable of cascading nucleophilic substitution reaction with the thiol group and amino group of GSH at a single reaction site,and showed the dual-color recognition of GSH,which improved the selectivity of GSH also was an extension of GSH probes.The probe Rho-DEA was based on a TICS fluorophore,and the intramolecular cascade nucleophilic substitution reaction occurs with Cys/Hcy.The thiol substitution of the first step reaction with Cys/Hcy was quenched due to intersystem crossing to triplet state,so GSH can be selectively recognized from the fluorescence signal.Rho-DEA has the ability of mitochondrial localization,and finally realized in situ dual-color fluorescence recognition of GSH in mitochondria.

可调控结构色互穿纳米水凝胶的合成及凝胶化转变

研究合成了具有温度和pH响应性的PNIPAM/PAphe互穿纳米水凝胶,通过红外光谱、扫描电镜、动态光散射仪、光纤光谱仪等技术,详细研究了互穿纳米水凝胶的结构和形貌、粒径与分散性、温度和pH响应性、结构色调控与光子晶体自组装,以及凝胶化转变行为。根据红外光谱和扫描电镜图确认了两种网络的有效互穿和其良好的单分散性。通过粒径分析可以得到随着PAphe含量的增加,互穿纳米水凝胶的粒径相应增大,但单分散性保持良好。利用温度和pH敏感性实验证明了该互穿纳米水凝胶的智能调控响应性,具体表现为:在温度上升或pH值下降的条件下,其粒径显著减小。结合光纤光谱图,进一步发现该互穿纳米水凝胶能够通过调整粒径大小来实现其结构色的可调控性。更为重要的是,通过试管倒置法发现在相变温度(32℃)以上该纳米凝胶具有从溶胶转变到凝胶的能力,展现了其在高度可调控的光学材料及生物医学领域中的应用潜力。