Poly(3-hexylthiophene-2,5-diyl) based diodes for ionizing radiation dosimetry applications

Accurate measurements of radiation dose are essential prerequisites for the safe and effective use of ionizing radiation in diagnostic and therapeutic medical applications. Recently, dosimeters based on organic polymers have been developed for this purpose. In this work, Poly(3-hexylthiophene-2,5-diyl) (P3HT) based organic diodes were evaluated as potential radiation dosimeters by quantifying the radiation-induced photocurrent under various measurement conditions. Control devices were fabricated in which the P3HT was replaced by polystyrene (PS) for the purpose of quantifying the non-photocurrent contribution to the measured signal. Net photocurrent was determined by subtracting the signal from the PS devices from the signal in the P3HT devices under identical measurement conditions. The responses of these devices were tested in various beam qualities: 100 kVp, 180 kVp, 300 kVp and 6 MV, 18 MV photons. The influences of electric field, film thickness and dose rate on dosimeter sensitivity were investigated. The diodes produced a linear increase in current with increasing dose rate. They demonstrated an increase in sensitivity with increased instantaneous dose rate and an increase in sensitivity at the lowest average dose rates studied here. The sensitivities for different energies were 22.9 nC/Gy, 21.8 nC/Gy and 21.4 nC/Gy for 100 kVp, 180 kVp and 300 kVp, respectively; and 14.5 nC/Gy, 14.7 nC/Gy for 6 MV and 18 MV, respectively for device with P3HT thickness 29 μm.     

磷酸根插层水滑石阻燃剂的研制

采用共沉淀法制备镁-铝水滑石[Mg4A l2(OH)12CO3.4H2O]前驱体,由离子交换法组装磷酸根插层水滑石。用化学分析,XRD,DTA-TG等手段,对样品进行分析和表征,并测试其阻燃性能。结果表明,磷酸根插层水滑石用于高分子材料,具有阻燃、消烟、填充功能,是无卤的无机阻燃剂新品种。     

基于HT46R23的智能湿度仪

针对目前常见的湿度计功能比较单一的特点，开发出一种基于HT46R23单片机，配以专用HU1015N型湿度传感器的智能湿度仪。这种智能湿度仪具有成本低、集成度高、组装方便等优点。用户通过按键可设定检测湿度值范围，当湿度值超出上下限参数值时，有报警输出功能。详细说明其构成原理、设计方法及软件流程图。     

A comprehensive review on poly(3-alkylthiophene)-based crystalline structures,protocols and electronic applications

Poly (3-alkylthiophenes) (P3ATs) particularly poly (3-hexylthiophene) (P3HT) have vigorous tendency to crystallize into the ordered morphologies, thereby reflect the efficient electrical and optical characteristics. Here, the remarkable crystalline structures of P3ATs comprising single crystals, nanofibers, nano/microwires, nanoribbons, micelles, nanowhiskers, thin films, spherulites, etc. are thoroughly reviewed. In each category, the principle aspects like preparation methodologies (e.g., self-seeding, shearing, electrospinning, self-organization, epitaxial solidification, etc.), micro/nanostructures, orientation and optical properties are meticulously brought into consideration. Applications of the ordered P3AT structures in solar cells, organic field-effect transistors, and sensors as well as the theoretical studies are also highlighted. Furthermore, the polymorphism, sol-gel, nanoparticles, liquid crystalline morphology, and two-dimensional sheets are reviewed.     

A Low Temperature Route toward Hierarchically Structured Titania Films for Thin Hybrid Solar Cells

The requirement of high‐temperature calcination for titanium dioxide in (solid‐state) dye‐sensitized solar cells (DSSCs) implies challenges with respect to reduced energy consumption and the potential for flexible photovoltaic devices. Moreover, the use of dye molecules increases production costs and leads to problems related with dye bleaching. Therefore, fabrication of dye‐free hybrid solar cells at low temperature is a promising alternative for current DSSC technology. In this work the authors fabricate hierarchically structured titania thin films by combining a polystyrene‐block‐polyethylene oxide template assisted sol–gel synthesis with nano‐imprint lithography at low temperatures. The achieved films are filled with poly(3‐hexylthiophene) to form the active layer of hybrid solar cells. The surface morphology is probed via scanning electron microscopy and atomic force microscopy, and the bulk film morphology is examined with grazing incidence X‐ray scattering. Good light absorption by the active layer is proven by UV–vis spectroscopy. An enhancement in light absorption is observed and ascribed to light scattering in mesoporous titania films with imprinted superstructures. Accordingly a better photovoltaic performance is found for nano‐imprinted solar cells at various angles of light incidence.     

基于WVD-HT的SAR/ISAR多运动目标检测

本文提出和研究了基于Wigner-Ville分布(WVD)和Hough变换(HT)的合成孔径雷达(SAR)和逆合成孔径雷达(ISAR)对多运动目标成象的运动补偿新方法,给出了多运动目标检测、参数估算和运动补偿的主要步骤。理论分析、计算机和微波暗室模拟实验的结果表明,新方法对交叉项和噪声的抑制是有效的,它与单一的WVD法相比,提高了在噪声中对单个和多个运动目标检测及其参数估算的能力。     

6-姜烯酚诱导人结肠癌细胞HT29凋亡及与VEGFR2表达变化的关系

本文通过研究不同浓度6-姜烯酚诱导结肠癌细胞HT 29凋亡及与VEGFR2(血管内皮细胞受体2)不同表达之间的关系,以探讨其可能的抑制结直肠肿瘤相关机制。通过应用不同浓度6-姜烯酚(0、10、20和40μM)分别对体外细胞实验培养的HT29细胞株进行诱导处理24 h,相差倒置荧光显微镜观察细胞形态变化,CCK8(Cell Counting Kit-8)法测定药物诱导后细胞抑制率,Annexin V-FITC/PI流式细胞术检测不同浓度药物干预后细胞凋亡率及凋亡周期变化,最后用Western-blot检测分析VEGFR2蛋白不同表达变化。结果显示,与对照组相比,6-姜烯酚可呈浓度依赖性地诱导HT29凋亡,并使细胞周期G0/G1期细胞数由49.48%下降到24.39%和17.18%,而G2/M期细胞数由3.44%增加到34.78%和49.54%,进而将细胞周期阻滞在G2/M期,抑制细胞增殖,而且还不同程度地抑制了VEGFR2表达(p0.05)。结果表明,6-姜烯酚主要是通过诱导HT29凋亡进而起到抑制肿瘤细胞增殖的作用,这可能与不同程度抑制VEGFR2有关。     

钙钛矿敏化太阳电池制备工艺的优化研究

近年来,有机金属卤化物钙钛矿太阳电池因制备条件温和、光吸收强、能耗低、光电转化效率高等优点成为备受瞩目的研究热点。本文采用一步法制备钙钛矿材料甲胺碘化铅（CH3NH3PbI3）,并以廉价的聚（3-己基噻吩） （P3HT）为空穴传输材料在大气环境下制备钙钛矿敏化太阳电池。其中,通过调控TiO2浆料与松油醇、乙基纤维素的配比,分别制备具有250 nm、600 nm和1 000 nm三种不同厚度的TiO2纳米颗粒多孔薄膜光阳极,并系统考察钙钛矿前驱体溶液旋涂量对敏化电极结构形貌及光吸收性能的影响。太阳电池光电特性测试结果表明：当TiO2多孔层厚度为600 nm、钙钛矿前驱体溶液的旋涂量为40 μl时,CH3NH3PbI3能够较为完全地覆盖在多孔TiO2的表面,且钙钛矿材料的晶粒尺寸合适,TiO2孔道结构未被堵塞,有利于空穴导体的填充以及空穴的转移与传输,优化后的太阳电池光电转化效率达到5.17%。