基于三波段光学成像系统的地物辐亮度系数测量

为了对地面目标的辐亮度系数进行测量,研制了一套包含紫外、可见光和近红外三个波段的光学成像系统,用积分球对其辐亮度响应进行标定,得到辐亮度与图像灰度值和探测器积分时间的拟合方程。提出了一种地面目标辐亮度系数测量方法,采用两块不同辐亮度系数的漫反射板作为参照物,建立辐亮度方程组,最终求解得到的目标辐亮度系数表达式中将不含气象参数项。利用研制的三波段光学成像系统,对绿草地的辐亮度系数进行测量,使用辐亮度系数分别为0.99、0.50、0.20、0.10的四块漫反射板,测得草地的紫外、可见光和近红外波段的辐亮度系数分别为0.070、0.184和0.429。     

Efficient ternary organic solar cells with high absorption coefficient DIB-SQ as the third component

A series of organic solar cells(OSCs) are prepared with PTB7:PC_(71) BM as the host materials and DIB-SQ as the third component. The power conversion efficienty(PCE) of OSCs can be improved from 6.79% to 7.92% by incorporating 6 wt%DIB-SQ into donors, resulting from the enhanced short circuit current density(J_(SC) and fill factor(FF). The increased JSCof the optimized ternary OSCs should be attributed to the enhanced photon harvesting of teranry active layer by incorporating DIB-SQ. Meanwhile, FF of the optimized ternary OSCs should be due to the optimied phase separation. The open circuit voltage(V_(OC)) of tenray OSCs can be maintained at a constant of 0.75 V, indicating that all photogenerated holes willl be transported along the channels formed by PTB7.     

金纳米颗粒作为Cu2+氧化半胱氨酸的可视化指示剂及其应用

Cu2+能选择性氧化半胱氨酸,破坏半胱氨酸与金纳米颗粒之间金硫键的形成,阻止半胱氨酸导致的金纳米颗粒聚集。因而,金纳米颗粒可作为Cu2+氧化半胱氨酸的可视化指示剂,本实验据此建立了高选择性检测Cu2+的色度分析方法。在HCl-NaAc缓冲体系(pH 3.6)中,金纳米颗粒在525 nm处的吸光度值与Cu2+的浓度在8.0×10-8~2.0×10-6mol/L范围内呈良好的线性关系,相关系数为0.9962;检出限(3σ/k)为1.5×10-9mol/L。将本方法用于天然水体中Cu2+的测定,具有较好的精密度和准确度。     

Transport properties of topological insulators films and nanowires

The last several years have witnessed the rapid developments in the study and understanding of topological insulators. In this review, after a brief summary of the history of topological insulators, we focus on the recent progress made in transport experiments on topological insulator films and nanowires. Some quantum phenomena, including the weak antilocalization, the Aharonov-Bobm effect, and the Shubnikov-de Haas oscillations, observed in these nanostructures are described. In addition, the electronic transport evidence of the superconducting proximity effect as well as an anomalous resistance enhancement in topological insulator/superconductor hybrid structures is included.     

矩形非球面圆弧半径误差分离及补偿技术

研究了砂轮圆弧半径误差对大口径矩形轴对称非球面加工的影响。采用直线光栅式平行磨削的加工方式,建立了砂轮圆弧半径的误差分离的数学模型,分析影响面形精度的因素,根据加工及测量方式将砂轮圆弧半径误差分离出来,利用分离的砂轮圆弧半径误差更新砂轮圆弧半径,同时采用分离后的误差数据进行补偿加工。实验结果表明:对比不分离的补偿加工结果,粗磨和精磨条件下的分离误差补偿加工后的面形误差分别减小了14%和35%,该误差模型能够有效地分离出砂轮圆弧半径误差,分离误差效果明显,提高了加工的精度。     

大口径光学元件气囊抛光工具刚度可控性

为保证气囊抛光过程中抛光运动的高稳定性和均匀材料去除率,对气囊抛光非球面过程中气囊工具刚度的可控性进行了研究。通过分析气囊抛光大口径光学元件时工具的受力情况,计算了气囊工具的刚度,并分析了气囊抛光工具刚度对抛光时材料去除的影响及气囊工具刚度的影响因素。设计了气囊工具刚度控制算法并进行模拟试验,仿真结果表明,在刚度标准值根据加工要求设定以后,即可通过调节工件对气囊工具的反作用力,使得气囊抛光大口径光学元件过程中气囊工具刚度可控。     

改进灰导数和时间响应函数的新灰色预测模型

以白化方程为基础,利用梯形公式白化灰导数,同时根据最小二乘法求出时间响应函数中的常数c,得到一种改进的灰色预测模型.应用实例说明改进模型具有较高的预测和拟合精度.     

三维结构金纳米花的快速可控合成及其分析应用研究

以多巴胺(DA)为还原剂和包被剂,与氯金酸(HAuCl4)作用,一步合成得到具有高度复杂三维结构的金纳米花(AuNFs)。合成方法简单、可控、操作性强,只需70℃水浴反应10 min。实验发现,多巴胺溶液的新鲜程度和浓度是决定AuNFs形貌的关键因素,而4-(2-羟乙基)-1-哌嗪乙烷磺酸(HEPES)可用于调节AuNFs的尺寸,引入常用表面活性剂如Triton X-100、Tween-80、CTAB等会影响其形貌。由于AuNFs具有复杂的三维结构,在棱角处可能存在强电场,在催化、光热治疗等方面有较广阔的应用前景。     

Population inversion study of GaAs/AlGaAs three-quantum-well quantum cascade structures

A population inversion study of GaAs/AlxGa1-x As three-quantum-well quantum cascade structures is presented. We derive the population inversion condition (PIC) of the active region (AR) and discuss the PICs on different structures by changing structural parameters such as the widths of quantum wells or barriers in the AR. For some instances, the PIC can be simplified and is proportional to the spontaneous emission lifetime between the second and the first excited states, whereas some other instances imply that the PIC is proportional to the state lifetime of the second excited state.