超声波震荡法及润湿性增强法对单晶硅阶梯光栅闪耀面粗糙度的影响

单晶硅阶梯光栅闪耀面表面粗糙度会引起入射光的散射形成杂散光,为获得低杂散光的阶梯光栅槽形,减小单晶硅阶梯光栅闪耀面表面粗糙度显得尤为重要。在单晶硅湿法刻蚀工艺中,阶梯光栅闪耀面表面粗糙度较大的原因是反应生成的氢气易在硅片表面停留,形成虚掩模,阻碍反应的进一步进行。基于超声波空化作用及异丙醇(IPA)增加单晶硅表面润湿性的原理,在单晶硅湿法刻蚀制作阶梯光栅工艺过程中分别利用超声波震荡法及润湿性增强法对所制阶梯光栅闪耀面表面粗糙度进行改善。利用超声波震荡法所制阶梯光栅闪耀面表面粗糙度小于15nm,利用润湿性增强法所制阶梯光栅闪耀面表面粗糙度小于7nm。同时施以超声波震荡法和润湿性增强法,在异丙醇质量分数范围为5%~20%,超声波频率为100kHz,功率范围为30~50 W时,所制阶梯光栅闪耀面表面粗糙度小于2nm,而且当异丙醇质量分数为20%、超声波频率为100kHz以及超声波功率为50W时,所制中阶梯光栅闪耀面表面粗糙度达到1nm。实验结果表明,同时施以超声波震荡法及润湿性增强法,并优化实验参数可以制备更低粗糙度的阶梯光栅。     

Description of the shape evolution in the yrast states of 186Pt

¹⁸⁶Pt was tested in the framework of IBM-1 and the X(3) model. The results show that ¹⁸⁶Pt is located close to the shape phase transition point, but the B(E2) values little agree with the X(3) model. The shape evolution in the yrast states of ¹⁸⁶Pt is also discussed in detail. TRS calculation exhibits a flat bottomed potential at low spin states, but a relatively deep minimum at high spin states. It suggests that a shape evolution from vibrational mode to rotational mode happens in ¹⁸⁶Pt. The result is in agreement with the E-GOS calculation.     

凸面光栅成像光谱仪全视场自动化光谱定标系统设计

为了确定凸面光栅成像光谱仪的光谱特性,需要对凸面光栅成像光谱仪进行光谱定标。基于单色准直光法设计了一套全视场光谱定标系统,引入球面镜提供准直光,采用一块可以自由滑动和转动的折转镜改变定标光线的入射角,实现了全谱段自动化光谱定标。运用光学设计软件CODEV对光谱定标系统进行了部分光学模拟,证明了整个系统的可靠性。结合光谱定标系统的结构和特点,对整个光谱定标系统进行了精度分析。理论分析结果表明,该系统的光谱定标精度优于1%。该定标系统具有体积小、通用性强等特点,可为其他成像光谱仪的光谱定标提供参考。     

Non-Rayleigh photon statistics of superbunching pseudothermal light

Superbunching pseudothermal light has important applications in studying the second-and higher-order interference of light in quantum optics.Unlike the photon statistics of thermal or pseudothermal light is well understood,the photon statistics of superbunching pseudothermal light has not been studied yet.In this paper,we will employ single-photon detectors to measure the photon statistics of superbunching pseudothermal light and calculate the degree of second-order coherence.It is found that the larger the value of the degree of second-order coherence of superbunching pseudothermal light is,the more the measured photon distribution deviates from the one of thermal or pseudothermal light in the tail part.The results are helpful to understand the physics of two-photon superbunching with classical light.It is suggested that superbunching pseudothermal light can be employed to generate non-Rayleigh temporal speckles.     

Temperature dependence of spin pumping in YIG/NiOx/W multilayer

We report the temperature dependence of the spin pumping effect for Y₃Fe₅O₁₂ (YIG, 0.9 μm)/NiO (t_NiO)/W (6 nm) (t_NiO = 0 nm, 1 nm, 2 nm, and 10 nm) heterostructures. All samples exhibit a strong temperature-dependent inverse spin Hall effect (ISHE) signal I_c and sensitivity to the NiO layer thickness. We observe a dramatic decrease of I_c with inserting thin NiO layer between YIG and W layers indicating that the inserting of NiO layer significantly suppresses the spin transport from YIG to W. In contrast to the noticeable enhancement in YIG/NiO (t_NiO ≈ 1-2 nm)/Pt, the suppression of spin transport may be closely related to the specific interface-dependent spin scattering, spin memory loss, and spin conductance at the NiO/W interface. Besides, the I_c of YIG/NiO/W exhibits a maximum near the T_N of the AF NiO layer because the spins are transported dominantly by incoherent thermal magnons.     

基于微流体装置的微血管网内红细胞流动和分布特性的研究简

实体肿瘤血管具有扩张、扭曲、不规则分支以及分支间连接絮乱等特征. 为了考察这些特征对血液流动的影响,将肿瘤血管简化为垂直相互贯通的微血管网,借助微流体实验装置,以一定浓度的红细胞悬液作为流动介质,研究红细胞在微血管网中的流动和分布特性. 具体实验方案如下：首先,采用软刻蚀技术,在聚二甲基硅氧烷（polydimethylsiloxane, PDMS）上加工出微血管网;然后,采用微注射泵控制微血管网入口处的红细胞悬液流量,使用倒置显微镜和高速摄影系统观察并记录实验过程;最后,通过Matlab 软件包Piv-lab 及高速摄影配套软件对获得的视频图像进行处理,提取红细胞在微血管网中的流动和分布数据. 数据处理结果显示,红细胞在微血管网中的流动和分布特性受悬液内的红细胞压积（hematocit, Hct）的影响. 红细胞随悬液Hct 的不同呈现2 种运动轨迹：一种为仅沿着轴向微管道流动;另一种是从轴向微管道流入并穿过径向微管道,再进入另一侧的轴向微管道. 另外,入口流量相同时,红细胞在微血管网中的流动速度随Hct 变化呈现不同,Hct 为3% 和5% 的红细胞速度要明显高于Hct 为1% 的红细胞速度.     

环己烷氧化微孔催化剂的研究进展

环己烷氧化是化工生产中的重要反应之一,其氧化产物为重要的化工生产中间体,因此开发高效的环己烷氧化多相催化剂体系具有重要的理论意义和应用前景。本文综述了国内外环己烷选择氧化微孔催化剂的研究进展,分别对Y沸石、ZSM-5沸石及MOFs三大类微孔催化剂体系的组成及催化性能进行了介绍,最后展望了环己烷多相催化体系的发展趋势。     

An amperometric biosensor based on covalent immobilization of ascorbate oxidase on biocompatiable and low-toxic poly(thiophene-3-acetic acid) matrix

The biocompatiable and low-toxic poly（thiophene-3-acetic acid）（PTAA） matrix was successfully electrosynthesized in ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate（BmimPF₆） in comparison with the electrosynthesis of PTAA matrix in acetonitrile（ACN）.Ascorbate oxidase（AO） was used as a model for the development and application of biosensor.Vitamin C（VC） biosensors were facilely fabricated by the covalent immobilization of AO molecules on PTAA matrices electrosynthesized in ACN containing tetrabutylammonium tetrafluoroborate and BmimPF₆, respectively.Electrochemical impedance spectroscopy,scanning electron microscopy and FTIR spectroscopy indicated that AO molecules were covalently immobilized on PTAA matrices.Parameters of the as-obtained biosensors such as working potential,pH and temperature have been optimized.The amperometric biosensor based on PTAA matrix electrosynthesized in BmimPF₆ exhibited wider linear range,lower detection limit,higher sensitivity and bioaffinity,and better operational and storage stability than that electrosynthesized in ACN under optimal conditions.The as-obtained biosensor based on PTAA matrix electrosynthesized in BmimPF₆ was employed for the detection of VC content in commercial juices,and the result was close to the data given by manufacturers.Excellent results indicate that the PTAA matrix electrosynthesized in ionic liquid is a promising platform for the covalent immobilization of biologically-active species and the development of biosensors.     

正交光楔激光远场焦斑测量方法

为验证正交光楔激光远场焦斑测量方法在提取光斑高频组分、扩展CCD测量动态范围和减小光束质量测量误差等诸方面的有效性,以常用的光束质量因子作为衡量新方法有效性的指标,建立离焦光斑强度分布理论模型并搭建相应的实验平台进行实验验证。验证结果表明:新方法与传统远场测量方案相比,使实验所用CCD的测量动态范围拓展了约9倍,实际光斑远离中心主核区域的大量高频旁瓣分布特征从CCD背景噪声起伏中凸显出来,光束质量因子的测量平均相对误差也有约16%的精度改善。     

三七中Cu、Pb和Cd含量的不确定度评定

采用电感耦合等离子体-原子发射光谱法测定三七中Cu、Pb和Cd,对影响测定结果的不确定度来源进行了分析,在此基础上评定了分析结果的不确定度。研究表明,样品的重复性和校准曲线的拟合是影响不确定度的主要原因。