基于白光干涉的自稳定定量相位成像系统

提出和建立了基于白光干涉的自稳定定量相位成像系统.该系统以柯勒照明的白光迈克耳孙干涉计为基础,使用自稳定锁相电路以减少相位噪音,引入相移装置获得定量的相化位图像.实验分别以平面镜、标准测试图和聚苯乙烯小球为样品.获得了清晰的定量相位图像,实现了对样品的实时观测.该装置采用卤素灯照明,达到轴向分辨力5 nm,系统中的柯勒照明结构使其具有高空间相干性.实验结果表明,该装置能有效避免系统中其他光学表面(如系统中的透镜表面)干扰信号的影响.     

表面等离子体共振传感器的零角位置自动校准

基于角度扫描的表面等离子体共振(SPR)传感器,装置简单、容易实现、性能稳定,其测量精度由角度测量精度决定。提出了一种基于激光自混合干涉效应的零角位置自动校准方法,主要用于角度扫描的表面等离子体共振传感器零角位置的自动校准。这种方法克服了人眼观察时用自准直法难以判断两光点是否完全重合的缺点,其精度可满足实验要求。     

半导体激光自混合干涉仪稳定性的仿真分析

利用半导体激光器的Lang-Kobayashi方程,对半导体激光自混合干涉系统的动力学特性进行了仿真分析。研究结果表明,当光反馈系数较小时,激光器处于稳定状态,外腔长度不影响系统的稳定性;当光反馈系数较大时,激光器将进入不稳定状态,对于不同的外腔长度,激光器的稳定状态将发生变化。为实现大量程的位移或距离测量,光反馈系数必须足够小才能保证在较大外腔长度变化范围内,激光器始终处于稳定状态。     

激发压缩真空态的相位概率分布

应用Pegg和Barnett提出的相位算符和相位态理论,研究了激发压缩真空态的相位概率分布特性.数值计算结果表明,激发压缩真空态的相位概率分布主要受到相位参量和压缩参量的调节,相位参量使相位概率分布呈峰值结构,压缩参量的变化将影响相位概率分布的峰值强度,此外激发光子数对相位概率分布也有较大的影响.     

基于第一性原理的无铅无机钙钛矿Cs3Bi2X9(X=Cl、Br、I)光电性能表面效应研究

用基于第一性原理的密度泛函理论方法,对Cs₃Bi₂X₉（X=Cl、Br、I）的光电特性进行理论计算,并系统阐述这3种晶体的表面效应对光电性能的影响。结果表明,3种材料的光学特性由铋原子和卤素原子最外层p轨道上的价电子主导。在可见光区中,材料的吸收峰会随卤素原子序数的增加呈现红移,其中一维结构的Cs₃Bi₂Cl₉表面结构在光吸收能力上尤为特别且敏感;二维结构的Cs₃Bi₂Br₉光吸收能力会受厚度影响;零维结构的Cs₃Bi₂I₉非常稳定,且几乎不受表面特性和晶体厚度的影响。     

Electromagnetic-Interference-Shielding Effectiveness of Lyocell-Based Carbon Fabrics Carbonized at Various Temperatures

Lyocell is a biodegradable filament yarn obtained by directly dissolving cellulose in a mixture of N-methylmorpholine-N-oxide and a non-toxic solvent. Therefore, herein, lyocell fabrics were employed as eco-friendly carbon-precursor substitutes for use as electromagnetic interference (EMI) shielding materials. First, a lyocell fabric treated with polyacrylamide via electron beam irradiation reported in a previous study to increase carbon yields and tensile strengths was carbonized by heating to 900, 1100, and 1300 °C. The carbonization transformed the fabric into a graphitic crystalline structure, and its electrical conductivity and EMI shielding effectiveness (SE) were enhanced despite the absence of metals. For a single sheet, the electrical conductivities of the lyocell-based carbon fabric samples at the different carbonization temperatures were 3.57, 5.96, and 8.91 S m⁻¹, leading to an EMI SE of approximately 18, 35, and 82 dB at 1.5–3.0 GHz, respectively. For three sheets of fabric carbonized at 1300 °C, the electrical conductivity was 10.80 S m⁻¹, resulting in an excellent EMI SE of approximately 105 dB. Generally, EM radiation is reduced by 99.9999% in instances when the EMI SE was over 60 dB. The EMI SE of the three lyocell-based carbon fabric sheets obtained at 1100 °C and that of all the sheets of the sample obtained at 1300 °C exceeded approximately 60 dB.     

Current Analytical Strategies for Antibody–Drug Conjugates in Biomatrices

Antibody–drug conjugates (ADCs) are a new class of biotherapeutics, consisting of a cytotoxic payload covalently bound to an antibody by a linker. Ligand-binding assay (LBA) and liquid chromatography-mass spectrometry (LC-MS) are the favored techniques for the analysis of ADCs in biomatrices. The goal of our review is to provide current strategies related to a series of bioanalytical assays for pharmacokinetics (PK) and anti-drug antibody (ADA) assessments. Furthermore, the strengths and limitations of LBA and LC-MS platforms are compared. Finally, potential factors that affect the performance of the developed assays are also provided. It is hoped that the review can provide valuable insights to bioanalytical scientists on the use of an integrated analytical strategy involving LBA and LC–MS for the bioanalysis of ADCs and related immunogenicity evaluation.     

激光共振电离质谱法测量锡的同位素比

采用实验室研制的激光共振电离质谱仪,建立了锡(Sn)同位素的激光共振电离质谱分析方法.测量了锡原子的自电离态光谱,确认了锡的一条三色三光子共振电离路径,其各步激发/电离的激光波长分别为λ1=286.4 nm、λ2=811.6 nm、λ3=823.7 nm;通过将样品与氧化石墨烯溶液混合制样,有效提高了锡样品的电热原子化效率,1μg锡的总探测效率达到3×10-5以上,是直接滴样方式的4.5倍左右.采用本方法对锡、锑、硫(1:1:1,m/m)混合模拟样品进行测试,实现了锡的选择性电离,有效避免了测量过程中锑、硫对锡的同量异位素干扰,样品中主要同位素比116 Sn/120 Sn,117 Sn/120 Sn,118 Sn/120 Sn和119 Sn/120 Sn测量的相对标准偏差均°1%.结果表明,本方法能够有效解决TIMS、ICP-MS等商业质谱仪在锡同位素质谱分析过程中的同量异位素干扰难题,有望应用于反应堆乏燃料中裂变产物121m Sn、126 Sn的测量.     

LOCAL POLYNOMIAL DOUBLE-SMOOTHING ESTIMATION OF A CONDITIONAL DISTRIBUTION FUNCTION WITH DEPENDENT

Based on the idea of local polynomial double-smoother, we propose an estimator of a conditional cumulative distribution function with dependent and left-truncated data. It is assumed that the observations form a stationaryα-mixing sequence. Asymptotic normality of the estimator is established. The finite sample behavior of the estimator is investigated via simulations.     

An improved method to calculate the radio interference of a transmission line based on the flux-corrected transport and upstream finite element method

The radio interference (RI) from HVDC transmission lines can block communication systems. In this paper the RI of a HVDC transmission line has been analyzed by the superposition of the electromagnetic field generated by the corona current based on phase-model transformation, where the corona current can be solved by the flux-corrected transport and finite difference method combining the upstream finite element method for bipolar conductor model instead of corona cage or excitation function. Our calculated values for 0.5 MHz RI from the proposed method compare well with measured values from a 800 kV HVDC test line established in China. With this validation, we find that RI should increase with temperature, increase with altitude, and vary in a complex way with relative humidity. Therefore, the proposed method can be adopted in transmission lines design and electromagnetic environment evaluation.