多碱光电阴极光谱响应峰值位置移动技术研究

研究字多碱光电阴极光谱响应峰值位置移动技术。利用多碱光电阴极多信民测控技术，可以控制光电阴极光谱响应峰值位置，以满足不同性能光电管光谱匹配的需要，对夜天光辐射以及一些材料的光谱反射，利用多信息量测控技术，可以将多碱光电阴极的光谱响应峰值移至０．８μｍ处。     

NewS25与LEP光电阴极光谱响应特性的研究

研究了Ｎｅｗ Ｓ２５与ＬＥＰ＾＊光电阴极的光谱响应特性。从理论上分析了光电子逸出深度，光电阴极结构参量和光电阴极厚度对光谱响应特性的影响。并对实用三碱阴极的潜力进行了理论预测。明确指出集Ｎｅｗ Ｓ２５与ＬＥＰ＾＊之长获得的实用三碱阴极可以和Ⅲ－Ⅴ族ＮＥＡ阴极媲美。     

激活台内透射式GaAs光电阴极的光谱响应特性研究

利用在线光谱响应技术,对透射式GaAs光电阴极在高温激活和低温激活后的光谱响应特性进行了测试,计算并比较了高温激活和低温激活后阴极的积分灵敏度和光谱响应特性参数.结果发现,与高温激活相比,低温激活后GaAs光电阴极的积分灵敏度提高了13％,低温激活后阴极的截止波长和峰值波长均向长波有微小偏移.将已获得的测试曲线与铟封后的三代像增强器的光谱响应曲线进行了比较,结果发现铟封前后的光谱响应曲线存在明显差异.     

一种菁染料－聚合物薄膜的光存存储性能

用旋涂法制备了一种菁染料－聚合物薄膜，并研究了该染料－聚合物薄膜的光谱性质和光存储性能。该染料薄膜在６６０～８３０ｎｍ波段有较强的吸收和２０％以上的反射率。在最佳实验条件下，获得了５８ｄＢ的信噪比。信噪比（ＣＮＲ）、载波信号强度（Ｃ）和薄膜反射率变化（ΔＲ）的对数（ｌｇΔＲ）成正比     

铟封前后透射式GaAs光电阴极光谱响应特性的测试与分析

利用自行研制的光谱响应测试仪工程化样机,对透射式GaAs光电阴极在高温激活结束、低温激活结束以及铟封成管后的光谱响应特性进行了测试。结果显示,铟封后阴极整个响应波段的光谱响应下降,长波响应受到最显著的影响,表现为800~815 nm之间长波响应大幅度衰减,截止波长和峰值波长向短波移动,峰值响应和积分灵敏度减小,最终的光谱响应曲线变得平坦。阴极参量的计算结果反映铟封后阴极的表面逸出几率降低,说明铟封引起阴极表面激活层发生变化,使得能量较低的长波段光生电子不容易逸出,阴极长波响应和灵敏度随之降低。进一步分析了铟封过程中影响阴极表面激活层的因素。     

超二代微光像增强器多碱光电阴极膜厚测量研究

介绍了多碱光电阴极的光学性能和光谱反射率特性,测量了多碱阴极的光谱反射率曲线.该曲线与普通光学膜层光谱反射率曲线相比,形状较不规则,原因是多碱阴极膜层存在光吸收.光谱反射率曲线上的干涉峰是入射光在玻璃与阴极膜层界面反射和在阴极膜层与真空的界面反射的两束光发生干涉的结果.根据干涉的原理,如果阴极膜层所反射的两束光的光程差为二分之一波长的偶倍数时,光谱反射将出现干涉加强峰;如果阴极膜层所反射的两束光的光程差为二分之一波长的奇倍数时,光谱反射将出现干涉减弱峰.根据超二代像增强器光谱反射干涉峰对应的波长,可以计算出其阴极膜层的厚度约为191 nm,比二代像增强器阴极膜层的厚度增加了38％.多碱阴极膜层厚度是影响多碱阴极灵敏度的一个关键参量,仅仅靠人眼观察阴极膜层颜色的方法不准确.实践证明,利用光谱反射的方法来计算阴极膜层厚度的方法简单有效.如果在多碱阴极的制作过程中进行光谱反射率的监控,那么将可以精确控制阴极膜层的厚度,对多碱阴极的研究将会更加深入,多碱阴极的灵敏度也将会得到进一步的提升.     

一种菁染料—聚合物薄膜的光存存储性能

用旋涂法制备了一种菁染料－聚合物薄膜，并研究了该染料－聚合物薄膜的光谱性质和光存储性能，该染料薄膜在６６０～８３０ｎｍ波段有较强的吸收和２０％以上的反射率，在最佳实验条件下，获得了５８ｄＢ的信噪比，信噪比（ＣＮＲ）载波信号强度（Ｃ）和薄膜反射率变化（△Ｒ）的对数（ｌｇ△Ｒ）在正比。     

反射式NEA光电阴极Cs-O层厚度的在线测试

提出了对NEA光电阴极的Cs-O层厚度进行在线测试方法,介绍了NEA光电阴极评估系统的结构,随后介绍了在NEA光电阴极制备过程中的光谱响应的变化,得到了响应曲线。通过对响应曲线的在线测试,以获得NEA光电阴极Cs—O层的最佳厚度,根据实验结果提出了结论。     

GeSb_2Te_4相变光存储薄膜材料的短波长静态记录特性的研究

研究了单层ＧｅＳｂ２Ｔｅ４真空射频溅射薄膜在４００ｎｍ～８３０ｎｍ区域的吸收、反射光谱和光学常数（ｎ，ｋ），发现ＧｅＳｂ２Ｔｅ４薄膜在４００ｎｍ～６００ｎｍ波长范围内具有较强的吸收。在短波长静态测试仪上测试了ＧｅＳｂ２Ｔｅ４薄膜的光存储记录特性，发现在５１４．５ｎｍ波长用较低功率的激光辐照样品时薄膜在写入前后的反射率变化较大，擦除前后的反射率对比度较低，可通过膜层设计来提高     

GaAs光电阴极稳定性的光谱响应测试与分析

利用光谱响应测试仪对激活后的反射式GaAs(Cs,O)光电阴极进行了稳定性测试,获得了阴极随时间变化的光谱响应曲线,并表征了阴极在衰减过程中的性能参数变化.结果表明:积分灵敏度和峰值响应随着时间不断下降,截止波长向短波推移,表面逸出几率的下降是阴极衰减的直接原因.不同波长下光谱响应的衰减速率并不相同,波长越长,衰减速率越大,因此激活台内阴极在灵敏度衰减的同时长波响应能力也在不断下降.     

多碱阴极光吸收系数的研究

本文给出了多碱阴极Na_2KSb(Cs)光吸收系数经验公式.公式计算的吸收系数和实验曲线在可见光和近红外范围基本吻合.并根据量子力学处理,导出了吸收限附近的光吸收系数.从而解释了S-20和LEP~*光阴极量子产额曲线的差别.     

砷化镓光电阴极光谱响应与吸收率关系分析

为了研究砷化镓(GaAs)光电阴极光谱响应与吸收率曲线间的关系,采用分子束外延法(MBE)和金属有机化合物化学气相沉积法(MOCVD)制备了两类GaAs光电阴极,并测试得到了样品吸收率和光谱响应实验曲线.对每个样品的这两条曲线在同一坐标系中做最大值归一化处理,将归一的光谱响应曲线与归一的吸收率曲线做除法,得到了类似光电阴极表面势垒的形状.结果表明,两种方法制备的光电阴极光谱响应曲线相比吸收率曲线都发生了红移,MBE样品偏移量稍大于MOCVD样品.短波吸收率不截止,光谱响应截止于500 nm左右;可见光波段上,光谱响应曲线的峰值位置相比吸收率曲线红移了几百meV;近红外区域,光谱响应曲线的截止位置相比吸收率曲线红移了几个meV.MOCVD样品中杂质对带隙的影响更小,光谱响应相比吸收率发生的能量偏移更小.这些结论对提高GaAs光电阴极光电发射性能有指导意义.     

用于高速摄影变象管的软X射线光电阴极

光阴极由衬底(包括介质阴极的导电基底)和光电发射膜构成。采用了聚丙烯、Formvar和Paylene三种有机薄膜作阴极衬底。建立了这些薄膜的制备技术。用一台自制的软X射线单色仪在277—7469ev光子能量范围内测量了这些薄膜的透过率。 研究了CsI、CsBr、Au和MgF₂四种光电阴极的光电发射特性和光电发射与阴极厚度的关系,找出了最佳阴极厚度。用软X射线单色仪在277—7469ev光子能量范围内测量了最佳厚度阴极的绝对量子效率,四种阴极最大值分别为4.50、2.90、0.25和0.12。我们还在同一阴极衬底上分区制备了四种阴极,在变象管荧光屏上比较其亮度,结果和测量的一致。 用LAB5型表面分析仪对CsI和Au阴极的光电子初能量分布作了测量,CsI阴极光电子初能量分布半高宽远小于Au。因此CsI是适用于高速摄影变象管比较理想的软X射线光电阴极。     

Comparative research on the transmission-mode GaAs photocathodes of exponential-doping structures

Early research has shown that the varied doping structures of the active layer of GaAs photocathodes have been proven to have a higher quantum efficiency than uniform doping structures. On the basis of our early research on the surface photovoltage of GaAs photocathodes, and comparative research before and after activation of reflection-mode GaAs photocathodes, we further the comparative research on transmission-mode GaAs photocathodes. An exponential doping structure is the typical varied doping structure that can form a uniform electric field in the active layer. By solving the one-dimensional diffusion equation for no equilibrium minority carriers of transmission-mode GaAs photocathodes of the exponential doping structure, we can obtain the equations for the surface photovoltage (SPV) curve before activation and the spectral response curve (SRC) after activation. Through experiments and fitting calculations for the designed material, the body-material parameters can be well fitted by the SPV before activation, and proven by the fitting calculation for SRC after activation. Through the comparative research before and after activation, the average surface escape probability (SEP) can also be well fitted. This comparative research method can measure the body parameters and the value of SEP for the transmission-mode GaAs photocathode more exactly than the early method, which only measures the body parameters by SRC after activation. It can also help us to deeply study and exactly measure the parameters of the varied doping structures for transmission-mode GaAs photocathodes, and optimize the Cs-O activation technique in the future.     

Comparative research on the transmission-mode GaAs photocathodes of exponential-doping structures

Early research has shown that the varied doping structures of the active layer of GaAs photocathodes have been proven to have a higher quantum efficiency than uniform doping structures.On the basis of our early research on the surface photovoltage of GaAs photocathodes,and comparative research before and after activation of reflection-mode GaAs photocathodes,we further the comparative research on transmission-mode GaAs photocathodes.An exponential doping structure is the typical varied doping structure that can form a uniform electric field in the active layer.By solving the one-dimensional diffusion equation for no equilibrium minority carriers of transmission-mode GaAs photocathodes of the exponential doping structure,we can obtain the equations for the surface photovoltage(SPV) curve before activation and the spectral response curve(SRC) after activation.Through experiments and fitting calculations for the designed material,the body-material parameters can be well fitted by the SPV before activation,and proven by the fitting calculation for SRC after activation.Through the comparative research before and after activation,the average surface escape probability(SEP) can also be well fitted.This comparative research method can measure the body parameters and the value of SEP for the transmission-mode GaAs photocathode more exactly than the early method,which only measures the body parameters by SRC after activation.It can also help us to deeply study and exactly measure the parameters of the varied doping structures for transmission-mode GaAs photocathodes,and optimize the Cs-O activation technique in the future.     

Spectral Characteristics of Salinized Soils during Microbial Remediation ProcessesSCIEI北大核心CSCD

In this study, the spectral reflectance of saline soils, the associated soil salt content(SSC) and the concentrations of salt ions were measured and analysed by tracing the container microbial remediation experiments for saline soil (main salt is sodium chloride) of Dongying City, Shandong Province. The sensitive spectral reflectance bands of saline soils to SSC, Cl- and Na+ in the process of microbial remediation were analysed. The average dimension reduction of these bands was conducted by using a combination of correlation coefficient and decision coefficient, and by gradually narrowing the sampling interval method. Results showed that the tendency and magnitude of the average spectral reflectance in all bands of saline soils during the total remediation processes were nearly consistent with SSC and with Cl- coocentration, respectively. The degree of salinity of the soil, including SSC and salt ion concentrations, had a significant positive correlation with the spectral reflectance of all bands, particularly in the near-infrared band. The optimal spectral bands of SSC were 1 370 to 1 445 nm and 1 447 to 1 608 nm, whereas the optimal spectral bands of Cl- and Na+ were 1 336 to 1 461 nm and 1 471 to 1 561 nm, respectively. The relationship model among SSC, soil salt ion concentrations (Cl- and Na+) and soil spectral reflectance of the corresponding optimal spectral band was established. The largest R-2 of relationship model between SSC and the average reflectance of associated optimal band reached to 0.95, and RMSEC and RMSEP were 1.076 and 0.591, respectively. Significant statistical analysis of salt factors and soil reflectance for different microbial remediation processes indicated that the spectral response characteristics and sensitivity of SSC to soil reflectance, which implied the feasibility of high spectrum test on soil microbial remediation monitoring, also provided the basis for quick nondestructive monitoring soil bioremediation process by soil spectral reflectance.     

塔河地区主要岩石金属元素含量、物性参数与光谱特征间的关系研究

测试了采集自黑龙江省塔河地区的300块并进行抛光处理后的岩石样本350~2 500nm间光谱反射率、磁化率、密度、孔隙率和金属元素含量(Fe,Mn,Ti,Zr,V,Zn,Pb,Nb,Co,Bi),并计算了其光谱吸收深度。在此基础上,以相关性分析方法为依据,探讨了所采集岩石样本的金属元素含量、物性参数、反射光谱间的特征响应关系,计算了岩石样本金属元素和光谱吸收深度间的相关性系数、物性参数与光谱反射率的相关性系数,获得成果如下:(1)在410nm附近,闪长玢岩各金属元素与吸收深度间的相关系数都存在尖锐的波峰和波谷,相关系数达到极值。(2)岩石样本金属元素和吸收深度的相关性研究中,侵入岩的相关系数则显著高于其他岩石类型。(3)1 400nm附近,岩石样本金属元素与吸收深度、各物性参数与光谱反射率的相关性都存在尖锐的波峰和波谷。其中磁化率、密度、视孔隙率与光谱反射率的相关系数在可见光范围内波动变化较大。(4)在1 900~2 500nm范围内,金属元素与光谱吸收深度、各物性参数与光谱反射率间的相关系数波动较大,其中金属元素和光谱吸收深度呈显著相关,相关系数达到极值。进一步研究了岩石金属元素和物理特性与其光谱特征的关系,对于不同岩性的不同波段的反射率与不同金属元素间分布状态的探测,具有一定意义。     

修复过程中盐渍化土壤的光谱特征分析

该研究跟踪山东东营盐渍化土壤(盐分主要以氯化钠为主)的微生物修复盆栽实验,分析研究修复过程中土壤理化性质的改良以及相应的光谱特征变化。基于对修复过程中不同阶段土壤盐分含量(SSC)和Na+,Cl-等理化指标的化学分析及其同步的光谱测试,采用平均值降维方法,相关系数与决定系数相结合的方式,通过逐步缩小采样间隔,分析了土壤在微生物修复过程中盐分和盐分离子含量变化及其光谱响应的最佳波段和特征。结果表明,土壤在不同处理的微生物修复过程中,全波段平均光谱反射率与SSC的变化趋势和幅度几近一致,与Cl-含量变化趋势和幅度完全一致。在光谱测试的全波段范围内,SSC及盐分离子含量与光谱反射率呈显著正相关,在近红外波段的反射率变化尤为显著。在此基础上,基于调整光谱采样间隔方法分析获得的盐分及其离子含量最佳光谱响应波段反射率,建立了土壤光谱反射率与盐分含量及其离子含量的关系模型。其中SSC的最佳响应波段1 370～1 445和1 447~1 608 nm,Cl-,Na+的最佳响应波段分别为1 336~1 461和1 471~1 561 nm,建立的模型其R2最高值达到了0.95,RMSEC,RMSEP最大值分别为1.076和0.591。不同处理的土壤微生物修复结果的显著性统计分析及其相应的光谱特征变化,充分显示了土壤盐分含量的光谱响应特征及其敏感性,对发展基于高光谱的土壤盐渍化快速分析诊断方法具有重要意义。