摘要：Two-dimensional(2D)hybrid perovskites with the Ruddlesden-Popper lattice(A')_(2)(A)_(n-1)M_(n)X_(3n+1)are emerging as the promising optoelectronic candidates,both the inorganic and organic ingredients of which can be tailored to modulate the physical ***,there is a scarcity of 2D multilayered motifs with the A-site large-size cations occupying perovskite ***,by rational mixedcation alloying,we present a new 2D hybrid perovskite,(4-TFBMA)_(2)(DMA)Pb_(2)I_(7)(1),in which the secondary cation of CH_(3)NH_(2)CH_(3)^(+)(DMA)is located inside the perovskite cage while the aromatic 4-(trifluoromethyl)benzylammonium(4-TFBMA)cation acts as a spacer *** from the quantum structure of alternating organic spacers and inorganic networks,crystal-array detectors of 1 show fascinating in-plane photodetection responses of large detectivity(~2.95×10^(12)Jones)and responsivity(~1.97AW^(-1)),comparable to those of some inorganic 2D *** addition,a fast response rate(~264μs)and a low dark current are also realized,related to the high crystalline quality and suppression of the hopping barrier due to the insulating organic spacing *** result sheds light on the further exploration of new 2D hybrid perovskites toward high-performance photodetector applications.

摘要：本文设计了一种梯形的周期极化掺镁铌酸锂(PPMgLN)波导,并通过在传播方向上引入温度梯度来拓宽其倍频(SHG)过程的泵浦光源可接收带宽。通过有限差分的光束传输法,计算波导的有效折射率,并进行波导尺寸的设计。结果表明,通过改变梯形波导不同位置的温度,使其形成一个温度梯度,可拓宽泵浦光源的波长可接收带宽。本文所设计的PPMgLN波导最大泵浦光源可接收带宽为C波段,即1 530~1 565 nm,该波导可倍频C波段,得到输出波段带宽为765~782.5 nm,温度调谐范围为30~150℃。

摘要：本文演示了紧凑的绿色和近红外双色连续波激光光源,其发射波长分别为516 nm和775 nm。设计并制造了级联的周期性极化掺镁铌酸锂晶体,用于同时转换通信波长的二次谐波(SHG)和三次谐波(THG),可以在相同温度下获得绿色和近红外激光的输出。通过建立一个单程激光测量系统,在2 W泵浦功率下获得516 nm的0.15 mW绿光和775 nm的1.19 mW的光,晶体温度控制在30.8℃。实验结果将为单激光器泵浦的紧凑型双波长共线激光器提供重要的案例。

摘要：深圳茂宝大厦采用毛石砌筑的建筑边坡挡土墙,设计、施工以及周边环境等因素导致墙体出现鼓肚、开裂。为改善边坡的安全状况,消除隐患,采用对墙体灌浆、喷锚、预应力锚索和格构梁等综合加固方法。试验证明,采用多种方法对危险挡土墙进行加固是可行的,且节约了成本。

摘要：针对缸体中齿轮室集成结构越来越普遍,加大了主体芯制芯难度的情况,研究了齿轮室集成铸件主体芯射砂紧实和固化时间的影响因素。通过分析射砂嘴、砂芯排布与射砂效果的关系,以及排气设计与吹胺固化时间的关系,最终得到了适合笔者公司的齿轮室集成铸件主体芯制芯的最优方案。经实践,主体芯制芯80%左右可实现一次射砂,且吹胺固化时间降为了55 s左右。