低银医用X光胶片的研制

对几种增黑剂进行了筛选实验研究，选用了两种增黑剂组合使用，提高了遮盖力，使医用Ｘ光胶片涂布银量由原业的９ｇ／ｍ２降到了６．８ｇ／ｍ２，与美国医用Ｘ光胶片涂布银量（６．７ｇ／ｍ２）相当，照相性能不低于国产医用Ｘ光胶片。     

[Mn(S-S)(N-N)]配合物的荧光特性与光敏性研究

通过透射电镜表征了标题配合物[Mn(S-S)(N-N)](S-S=mnt2-,1,2-二氰基乙烯-1,2-二硫醇离子;N-N=5-NO2-phen,5-硝基-1,10-邻菲咯啉)固态形貌,TEM和EDP照片显示标题配合物是一种纳米级(颗粒直径约40nm)的微晶粉体。测量了配合物[Mn(S-S)(N-N)]在二甲基亚砜(DMSO)、二甲基甲酰胺(DMF)、丙酮(CH3COCH3)等溶剂中的电子吸收光谱和电子发射光谱,该配合物在350~632nm间显示较强的荧光发射带。报道了掺杂有标题配合物[Mn(S-S)(N-N)]的CdS-PVA复合膜的暗态导电性和光电导性,研究了[Mn(S-S)(N-N)]对CdS的光敏化作用与其电子光谱间的关系。     

Modulation of Biodistribution,Pharmacokinetics, and Photosensitivity with the Delivery Vehicle of a Bacteriochlorin Photosensitizer for Photodynamic Therapy

Intravenous (i.v.) formulations with various amounts of organic solvents [PEG₄₀₀, propylene glycol (PG), cremophor EL (CrEL)] were used to deliver a fluorinated sulfonamide bacteriochlorin to mice, rats, and minipigs. Biodistribution studies in mice showed that a low‐content CrEL formulation combines high bioavailability with high tumor‐to‐muscle and tumor‐to‐skin ratios. This formulation was also the most successful in the photodynamic therapy of mice with subcutaneously implanted CT26 murine colon adenocarcinoma tumors. Pharmacokinetic studies in mice and minipigs revealed that with the same low CrEL formulation, the half‐life of the photosensitizer in the central compartment was longer in minipigs. Differences in biodistribution with the various formulations, and in pharmacokinetics between the two animal species with the same formulation, are attributed to the interaction of the formulations with low‐density lipoproteins (LDLs). Skin photosensitivity studies in rats showed that 30 min exposure of the skin to a solar simulator 7 days after i.v. administration of the fluorinated sulfonamide bacteriochlorin at 1 mg kg^?1 did not elicit significant skin reactions.     

High-Integrated-Photosensitivity Negative-Electron-Affinity GaAs Photocathodes with Multilayer Be-Doping Structures

The effect of changing Be doping concentration in GaAs layer on the integrated photosensitivity for negative-electron-affinity GaAs photocathodes is investigated.Two GaAs samples with the monolayer structure and the multilayer structure are grown by molecular beam epitaxy.The former has a constant Be concentration of 1e19cm-3,while the latter includes four layers with Be doping concentrations of 1e19,7e18,4e18,and 1e18cm-3 from the bottom to the surface.Negative-electron-affinity GaAs photocathodes are fabricated by exciting the sample surfaces with alternating input of Cs and O in the high vacuum system.The spectral response results measured by the on-line spectral response measurement system show that the integrated photosensitivity of the photocathode with the multilayer structure enhanced by at least 50% as compared to that of the monolayer structure.This attributes to the improvement in the crystal quality and the increase in the surface escape probability.Different stress situations are observed on GaAs samples with monolayer structure and multilayer structure,respectively.     

改进型[Cs Rb]2OAg光阴极的制备研究

利用改进工艺制备的[Cs Rb]2OAg光阴极,具有灵敏度高、热发射低和重复性好等优点。特别是改善了变像管的背景亮度。并提出[Cs Rb]2OAg光阴极的表面能带结构模型,对实验结果给予了比较满意的解释。     

改进型四碱光电阴极的结构研究

本文给出用新技术制作[Cs.Rb]Na_2KSb结构的光电阴极,具有灵敏度高、热发射低和重复性好等优点,特别是改善了光电器件的性能。并提出了四碱光电阴极的复合表面能带结构模型,对上述的实验结果给予了满意的解释。     

鲁明胶介质中AgBr／I纳米粒子的生长与感光性能

本文以鱼明胶为分散介质 ,采用双注法制备AgBr/I纳米粒子乳剂 ,控制银盐与卤溶液的注入速率 (R) ,以TEM观测了粒子的生长 ,据此探讨了该乳剂中AgBr/I纳米粒子平均粒径 ( d)及分布 (±σ)与反应条件的关系 .发现在R为 1 .3mmol/min— 8mmol/min范围内 ,随R增大 , d减小 ,R d间呈良好的线性关系 .除个别外 ,±σ值变化不明显 .对于该纳米粒子乳剂采用二氧化硫脲进行化学敏化 ,结果表明 :适当增加二氧化硫脲的加入量和延长敏化时间 ,均可有效提高乳剂的感光度 ,并有助于改善其低照度互易律失效 ,此外还揭示了曝光光源色温对该乳剂感光性能的影响 .     

载氢光纤光致折射率变化量与曝光时间关系的测量

对普通载氢光纤光致折射率变化量与曝光时间的关系进行了实验测量研究。针对不同曝光时间导致的光栅强度不同, 分别提出了均匀光栅最大反射率测量模型和反射率零点带宽测量模型, 并分析了两个模型由于布拉格反射波长的测量误差对光致折射率变化量计算结果造成的影响。结果表明, 244 nm氩离子倍频激光器输出光功率为40 mW时, 普通载氢光纤光致折射率变化量随曝光时间总体上呈现指数分布关系Ac=1.632×10-6 t 0.76912; 在曝光时间较短时, 造成的光栅强度较弱, 光致折射率变化量有明显的指数增长趋势, 之后是一段较好的线性区域, 这时两个测量模型的结果得到了很好的印证, 随着曝光时间的继续增加, 光致折射率变化量达到饱和。     

An Integrated Flexible All-Nanowire Infrared Sensing System with Record Photosensitivity

Infrared (IR) photodetectors are a key optoelectronic device and have thus attracted considerable research attention in recent years. Photosensitivity is an increasingly important device performance parameter for nanoscale photodetectors and image sensors, as it determines the ultimate imaging quality and contrast. However, photosensitivities of state-of-the-art low-dimensional nanostructure-based IR detectors are considerably low, limiting their practical applications. Herein, a biomimetic IR detection amplification (IRDA) system that boosts photosensitivity by several orders of magnitude by introducting nanowire field effect transistors (FETs), resulting in a peak photosensitivity of 7.6 × 10⁴ under an illumination of 1342 nm, is presented. Consequently, high-contrast imaging of IR light is obtained on the flexible IRDA arrays. The image information can be then trained and recognized by an artificial neural network for higher image-recognition efficiency. This work provides a new perspective for developing high-performance IR imaging systems, and is expected to undoubtedly enlighten future work on artificial intelligence and biorobotic systems.     

Nonvolatile Perovskite‐Based Photomemory with a Multilevel Memory Behavior

Solution‐processable organic–inorganic hybrid perovskite materials with a wealth of exotic semiconducting properties have appeared as the promising front‐runners for next‐generation electronic devices. Further, regarding its well photoresponsibility, various perovskite‐based photosensing devices are prosperously developed in recent years. However, most exploited devices to date only transiently transduce the optical signals into electrical circuits while under illumination, which necessitates using additional converters to further store the output signals for recording the occurrence of light stimulation. Herein, a nonvolatile perovskite‐based floating‐gate photomemory with a multilevel memory behavior is demonstrated, for which a floating gate comprising a polymer matrix impregnated with perovskite nanoparticles is employed. Owing to the well photoresponsibility introduced by the embedded nanoparticles, the device is enabled to access multiple wavelength response and the functionalities of recording power/time‐dependent illumination under no vertical electrical field. Intriguingly, a nonvolatility of photorecording exceeding three months with a high On/Off current ratio over 10⁴ can be achieved.