摘要：Quasi-two dimensional(2D)perovskites have emerged as a promising class of materials due to their remarkable photoluminescence efficiency,which stems from their exceptionally high exciton binding *** spatial confinement of excitons within smaller grain sizes could enhance the formation of biexcitons leading to higher radiative recombination ***,the synthesis of high-quality quasi-2D perovskite thin films with controllable grain sizes remains a challenging *** this study,we present a facile method for achieving quasi-2D perovskite thin films with controllable grain sizes ranging from 500 to 900 *** is accomplished by intermediate phase engineering during the film fabrication *** results demonstrate that quasi-2D perovskite films with smaller grain sizes exhibit more efficient bound exciton generation and a reduced stimulated emission threshold down to 15.89µJ cm^(−2).Furthermore,femtosecond transient absorption measurements reveal that the decay time of bound excitons is shorter in quasi-2D perovskites with smaller grain sizes compared to that of those with larger grains at the same pump density,which is 230.5 *** observation suggests a more efficient exciton recombination process in the smaller grain size *** findings would offer a promising approach for the development of efficient bound exciton lasers.

摘要：Submicron scale temperature sensors are crucial for a range of applications,particularly in micro and na-noscale *** promising solution involves the use of active whispering gallery mode(WGM)*** resonators can be remotely excited and read out using free-space structures,simplifying the process of *** this study,we present a submicron-scale temperature sensor with a remarkable sensitivity up to 185 pm/℃based on a trian-gular MAPbI3 nanoplatelet(NPL)***,as temperature changes,the peak wavelength of the laser line shifts *** unique characteristic allows for precise temperature sensing by tracking the peak wavelength of the NPL *** optical modes are confined within the perovskite NPL,which measures just 85 nm in height,due to total internal *** NPL laser boasts several key features,including a high Q of~2610 and a low laser threshold of about 19.8μJ·cm^(−2).The combination of exceptional sensitivity and ultra-small size makes our WGM device an ideal candidate for integration into systems that demand compact temperature *** advancement paves the way for significant prog-ress in the development of ultrasmall temperature sensors,opening new possibilities across various fields.

摘要：介绍了二维层状钙钛矿材料的晶体结构及其基本光电特性;总结了二维层状钙钛矿材料在太阳电池、发光二极管、光电探测器等领域的最新应用;指出该类材料目前存在的主要问题和发展前景,以期为高性能二维层状钙钛矿光电器件的设计和制备提供参考。

摘要：3从分子层面设计稳定钙钛矿薄膜虽然封装已被证明是一种有效的提高钙钛矿光电子器件寿命的方法,但它是一种后处理方法,在封装之前仍会发生材料降解。因此,寻找解决钙钛矿制作阶段稳定性问题的新策略至关重要。通过使用化学添加剂修饰界面,与钙钛矿材料反应生成稳定的氢键或疏水性官能团,使钙钛矿自身稳定性得到了改善。

摘要：宽谱响应光电探测器在图像传感和光通信等领域应用前景广阔。金属微纳结构通过激发表面等离激元共振效应可高效产生热载流子,将它们与宽带隙半导体构成异质结构,便可利用热载流子开发出低成本宽谱响应光电探测器。研究设计了一种基于Au/TiO_(2)复合纳米结构的热电子光电探测器。其中TiO_(2)层经退火后形成尺度约为百纳米的凹凸结构,Au纳米颗粒层与用作电极的保形Au膜共同组成了激发表面等离激元共振的纳米结构。由于Au/TiO_(2)复合纳米结构的协同作用,该器件在400~900 nm范围内具有宽谱光吸收性能,器件的平均光吸收效率为33.84%。在此基础上,该器件能够探测TiO_(2)本征吸收波段以外的入射光子。例如,在600 nm波长处,器件的响应率为9.67μA/W,线性动态范围为60 dB,器件的上升/下降响应速度分别为1.6 ms和1.5 ms。此外,利用有限元法进行了仿真计算,通过电场分布图验证了Au/TiO_(2)复合纳米结构中所激发的丰富表面等离激元共振效应是其实现宽谱高效探测的原因所在。

摘要：超材料窄带滤色片由于结构紧凑、体积小、制备工艺简单和成本较低等优点,其常被用于光电探测和成像系统等领域。利用银和二氧化硅交替膜制备的周期性超材料狭缝阵列,实现了在可见光范围中心波长可调的窄带过滤颜色性能。研究了狭缝宽度、狭缝周期、金属银膜厚度与介质层厚度之间的比值和超材料厚度对该滤色片透射性能的调控规律,得到了具有较高透射效率且中心波长可调的窄带滤色片。最终实现半峰全宽17～30 nm、透射率约50%、在可见光500～760 nm波段实现中心波长可调且色纯度较好的滤色片。该结果为新型窄带滤色片的设计提供了崭新的思路。

摘要：为了提高拖拉机柴油发动机曲轴的设计和优化效率,将有限元仿真分析方法引入到了曲轴的设计中,并通过曲轴的三维建模和仿真分析,对曲轴进行了优化设计,在满足极限屈服力的条件下,降低了曲轴的质量,节省了曲轴加工制造的原材料。最后,通过有限元分析方法,对曲轴的共振情况、强度和疲劳情况进行了有限元分析,结果表明:优化后的曲轴不存在共振情况,且满足强度和疲劳设计要求,有效提高了曲轴的设计水平。

摘要：采用ANSYS有限元通用软件,对设计开发的圆环主半径54 mm、圆柱高180 mm、横向圆柱长45 mm、冷却水初始温度320 K、冷却器内壁温度525 K的内冷却器-U形管内冷却水速度为6～14 m/s时,对流场温度场耦合作用下冷却水流动状况进行数值模拟。结果表明,进口速度太小,易在弯曲区形成涡流,速度太大,易在弯曲区产生更大的流速,对管壁冲击较大,影响其使用寿命;所以内冷却器进口速度在10 m/s时冷却效果最佳。

摘要：近年来,工农业排放的重金属离子产生了严重的水体污染;这些重金属离子浓度低,通过吸附法可以有效处理这些污染问题。吸附法的关键在于高效吸附材料的设计和制备。纤维素是可再生的高分子聚合物,具有储量丰富、来源广泛等优点,纤维素材料经过改性后对重金属离子具有良好的吸附能力。介绍了纤维素的结构特点、吸附原理和不同改性方法,重点比较了纤维素的物理改性、直接化学改性和接枝改性等不同改性方法和对重金属离子的吸附的影响,并展望了纤维素基吸附材料的发展前景和方向。

摘要：以玉米淀粉、丙烯酸、膨润土为原料,过硫酸铵为引发剂,采用水溶液聚合法制备超强吸水树脂,并对产物进行性能测试。在得到最佳反应条件的基础上,考察了不同交联剂对此类超强吸水树脂性能、结构的影响,并优选较适合淀粉类超强吸水树脂的交联剂。以AlCl3为交联剂,且AlCl3用量为0.015%时,所得超强吸水树脂的吸去离子水量达到最高,为433.96 g/g,AlCl3用量为0.01%时,吸0.9%的NaCl溶液量达到最高,为73.76 g/g。