共查询到19条相似文献,搜索用时 187 毫秒
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提出了一种新的激光器腔面钝化方法.先用(NH4)2S溶液硫化解理后的激光器腔面,然后使用磁控溅射方法对激光器的前腔面镀ZnS钝化膜、后腔面镀Si/SiO2高反射膜.ZnS钝化层光学厚度为λ/4,在中心波长为808 nm处透过率可达95.5%.钝化前激光器的光学灾变损伤(COD)阈值为1.6 W,钝化后为2.0 W,提高了25%倍;未镀膜的激光器阈值电流为0.25 A,经硫化再镀ZnS后阈值电流为0.20 A,降低了20%.实验结果表明,经硫化后溅射ZnS对激光器腔面具有良好的钝化和增透效果. 相似文献
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CASIO首款陶瓷镜头超薄机型S100 此前,CASIO曾推出过DC机身最轻薄的S1、S2等机型,不过时过境迁,现在面对SONYT11、美能达Xt、Pentax S4i等机型功能日渐强大的步步进逼,尤其是出色的光学变焦功能,因此CASIO这次也按捺不住,要以新技术来抗击对手,推出更为轻薄的机型来巩固自己的"轻薄DC"机型地位.S100是CASIO在八月初刚发表了透明陶瓷镜头技术之后,全球率先应用该技术的新机型.作为首款采用该镜头的相机,无疑造就了S100成为新一代的袖珍机种,虽然在机身上采用的是2.8倍光学变焦镜头,但借助透明陶瓷镜头技术,S100仍可算是超薄型DC.机身尺寸仅为88mm×57mm×16.7mm,不含充电池与储存卡的机身重量也只是113g,堪称目前最迷你的光学变焦相机了. 相似文献
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本专利介绍了阴极射线管用 Y_2O_2S:Eu、Y_2O_2S:Tb、Gd_2O_2S:Tb、Y_2O_2S:Tb、Dy 发光材料制备的改进方法。实例1称量 Y_2O_3 95克、Tb_4O_7 5克、S 30克、Na_2CO_3 30克、K_3PO_4 8克充分混合后,放入氧化铝坩埚,N_2气氛中1100℃4小时烧成,烧结物用去离子水洗5次.1当量 HNO_3洗1次。再用去离子水洗净,干燥后得到的产物加 S 30克、Na_2CO_3 30克、K_3PO_4 8克充分混合,放入氧化铝坩埚.N_2气中1100℃3小时烧成。所得产物用去 相似文献
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光学微分不仅是一种重要的光学-数学运算,而且是提取图象轮廓,进行图象识别的一种手段。本文提出用非线性记录的全息复合光栅作为频率平面模片,用一级衍射可以得到一阶光学微分,二级衔射可以得到二阶光学微分。 在相干光处理系统中,用差分法进行光学微分已由S.K.Yao和S.H.Lee提出,他们用Vonder Lugt方法分别综合出一阶微分和二阶微分的频率平面模片。本文提出用非线性记录的全息复合光栅作为频率平面模片,可同时用它得到一阶和二阶光学微分,因而方法较为简便。 相似文献
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光学气敏材料吸附气体分子后导致光学性质发生变化,运用这一原理来检测环境中的气体成分,称为光学气敏效应。采用基于密度泛函理论(DFT)体系下的第一性原理平面波超软赝势方法,研究了光学气敏材料金红石相TiO2(110)表面吸附H2S分子的微观特性,计算了TiO2(110)表面吸附能、电荷密度、态密度和光学性质的变化。结果表明,TiO2最稳定的表面是终止于二配位O原子的(110)面,只有含有氧空位的表面才能稳定吸附H2S,且氧空位比例越高,越有助于H2S吸附于表面;表面吸附H2S以水平吸附方式为主,在氧空位比例达到33%时,吸附能为0.7985eV;吸附的实质是表面氧空位具有氧化性,氧化了H2S分子。在可见光400~760nm范围内,存在氧空位的TiO2(110)表面吸附H2S后都可改善表面的光学性质。氧空位缺陷浓度越高,改善材料对可见光的吸收和反射能力越强,光学气敏响应能力越佳。 相似文献
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Adams S.S. Karst N. Murugan M.K. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》2010,56(1):103-112
Complex orthogonal space-time block codes (COSTBCs) based on generalized complex orthogonal designs (CODs) have been successfully implemented in wireless systems with multiple transmit antennas and single or multiple receive antennas. It has been shown that for a maximum rate COD with 2m-1 or 2m columns, a lower bound on decoding delay is (m-1 2m) and this delay is achievable when the number of columns is congruent to 0, 1 , or 3 modulo 4. In this paper, the final case is addressed, and it is shown that when the number of columns is congruent to 2 modulo 4, the lower bound on decoding delay cannot be achieved. In this case, the shortest decoding delay a maximum rate COD can achieve is twice the lower bound. New techniques for analyzing CODs are introduced with connections to binary vector spaces. 相似文献
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微波-Fenton法处理垃圾渗滤液的研究 总被引:1,自引:1,他引:1
微波法用于消除有机污染物,具有快速、高效、不污染环境的特点。实验采用微波促进Fenton法降解垃圾渗滤液中的有机污染物,研究了Fenton试剂用量、微波功率、微波作用时间和pH值等对化学需氧量(COD)去除率的影响。实验结果表明,微波Fenton法处理垃圾渗滤液能提高反应效率,有效降低垃圾渗滤液中的COD浓度。微波-Fenton法处理20 mL的COD浓度为896 mg/L的垃圾渗滤液的优化条件为:调节pH值小于3,加入6 mmol/L的硫酸亚铁溶液6 mL,加入1 mL的H2O2,在微波功率800 W下加热处理4 min,其出水COD浓度可降至200 mg/L。 相似文献
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腔面光学灾变(COD)是影响半导体激光器高功率输出和可靠性的重要问题。不同腔面膜的器件,其腔面光学灾变阈值差别很大。使用离子辅助沉积(IBAD)的工艺可以使基片表面更清洁,膜层更为牢固致密,同时可以改善由吸收、散射等损耗带来的激光输出功率下降。采取N2氛围中在激光器的腔面上涂镀不同的增透膜与介质高反膜来提高腔面光学灾变阈值。 以980 nm半导体激光器为例,进行对比实验,从老化结果中可以看到不同工艺与不同材料选择下腔面膜的腔面光学灾变的明显改善。 相似文献
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Architectures for packet switches are approaching the limit of electronic switching speed. This raises the question of how best to utilize advances in photonic technology to enable higher speeds. The authors introduce cascaded optical delay line (COD) architectures. The COD architectures utilize an extremely simple distributed electronic control algorithm to configure the states of 2×2 photonic switches and use optical fiber delay lines to temporarily buffer packets if necessary. The simplicity of the architectures may also make them suitable for “lightweight” all-electronic implementations. For optical implementations, the number of 2×2 photonic switches used is a significant factor determining cost. The authors present a “baseline” architecture for a 2×2 buffered packet switch that is work conserving and has the first-in, first-out (FIFO) property. If the arrival processes are independent and without memory, the maximum utilization factor is ρ, and the maximum acceptable packet loss probability is ϵ, then the required number of 2×2 photonic switches is O(log(ϵ)/log(γ)), where γ=ρ2/(ρ2+4-4ρ). If one modifies the baseline architecture by changing the delay line lengths then the system is no longer work conserving and loses the FIFO property, but the required number of 2×2 photonic switches is reduced to O(log[log(ϵ)/log(γ)]). The required number of 2×2 photonic switches is essentially insensitive to the distribution of packet arrivals, but long delay lines are required for bursty traffic 相似文献
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S. S. Shinde 《半导体学报》2015,36(7):073003-5
Cu2ZnSnS4 (CZTS) is a main candidate material for solar energy conversion through both photovoltaics and photocatalysis based on environmentally friendly elements and with a direct band gap of 1.5 eV. We report the synthesis of quasi Cu2ZnSnS4 microparticles with unprecedented narrow size distributions. The structural, morphological and core level analysis has been carried out by XRD, SEM and XPS techniques. These microparticles have shown excellent photocatalytic activity toward degradation of Rhodamine B dye (RhB) and TNT under visible light. The extent of mineralization has been analyzed by COD and TOC values. Photocatalytic water splitting for H2 generation has also been reported. 相似文献
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Ultraviolet (UV) absorption spectroscopy is used to detect the concentration of water chemical oxygen demand (COD). The UV absorption spectra of COD solutions are analyzed qualitatively and quantitatively. The partial least square (PLS) algorithm is used to model COD solution and the modeling results are compared. The influence of environmental temperature and turbidity is analyzed. These results show that the influence of temperature on the predicted value can be ignored. However, the change of turbidity can affect the detection results of UV spectra, and the COD detection error can be effectively compensated by establishing the single-element regression model. 相似文献
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为满足环境监测预警体系建设的需求,系统集成嵌入式技术、全光谱检测技术、电子舌检测技术,研制了基于物联网和光电子技术的环境自动检测系统,实现对pH、电导率、氨氮、浊度、色度、COD的在线检测。经实验验证系统性能良好,pH、电导率、氨氮、浊度和COD的测量精度分别为-0.02, 0.4%, 2.9%, 2.1%, 1.1%; 电导率、浊度、COD的测量检出限分别为0.7 μS/cm, 0.9NTU, 0.5 mg/L。实际水样比对测试符合要求,可满足水质在线快速监测的需求。 相似文献
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将多组分活性材料组合成新的结构用作电极材料是提高超级电容器性能的一种有效措施。采用典型的两步水热法与电沉积法制备了FeCo2S4/Ni(OH)2复合纳米材料,并表征其物理及电化学性能。结果表明,FeCo2S4纳米花被电沉积上的Ni(OH)2纳米片包围,形成三维互连网状结构,有利于电极材料与电解液的充分接触。所得的FeCo2S4/Ni(OH)2复合电极材料显示出极高的比电容(当电流密度为1 A·g^-1时,比电容达1588.2 F·g^-1)、优异的倍率性能及循环稳定性。此外,以FeCo2S4/Ni(OH)2为正极、活性炭为负极组装了非对称超级电容器。结果显示,非对称超级电容器具有高能量密度及良好的循环稳定性。 相似文献