同轴电极结构下真空放电等离子体生成及传播特性

采用放电电流为100~300 A、持续时间为13 s的单脉冲电源,设计了两种同轴电极结构作为放电阳极,分别为筒状电极、喷嘴状电极。利用MAXWELL 3D电场仿真软件对两种电极结构下的电场分布进行了仿真分析,并采用探针法对放电生成的等离子体的参数进行了测量,分析讨论了同轴电极结构对真空放电等离子体生成特性的影响。选取喷嘴状电极结构作为阳极,分别测量了采用铅、铝、铜三种材质的阴极时生成的等离子体的扩散速度及能量。实验与仿真结果表明:当阳极为喷嘴状电极时阴极尖端的电场强度较大,测得放电电流较大,击穿电压较低,等离子体密度也较大;采用铝材质阴极时生成的等离子体扩散速度最快,采用铅材质阴极时生成的等离子体的离子动能最大。     

Rotating polarizer,compensator, and analyzer ellipsometry

In this paper we propose theoretically a set of ellipsometric configurations using a rotating polarizer, compensator, and analyzer at a speed ratio of N1ω：N2ω：N3ω. Different ellipsometric configurations can be obtained by giving different integral values to N1, N2, and N3. All configurations are applied to bulk c-Si and GaAs to calculate the real and imaginary parts of the refractive index of the samples. The accuracies of all ellipsometric configurations are investigated in the presence of a hypothetical noise and with small misalignments of the optical elements. Moreover, the uncertainties in the ellipsometric parameters as functions of the uncertainties of the Fourier coefficients are studied. The comparison among different configurations reveals that the rotating compensator–analyzer configuration corresponds to the minimum error in the calculated optical parameters.     

Research of the planar optical fiber Bragg grating hydrophone probe

This paper presents the planar Fiber Bragg Grating （FBG） hydrophone probe sensing principle, and theoretically and experimentally researches the probe structure sensitivity, the receiving sensitivity frequency response characteristic and the acceleration response property. Planar sheet is made of stainless steel, its thickness is 0.15 mm, its diameter is 15mm, and the length of hollow circular shell is 20 mm. For this size of the structure, the probe structure sensitivity is up to 23 fm/Pa, which is about 7300 times of the value of the bare fiber. The resonance frequency is 6.5 kHz, and the amplitude-frequency curve of the receiving sensitivity response is relatively flat within the frequency range of 100 Hz to 5.5 kHz. The output yielded by one unit acceleration （1m/s2） is equivalent to （2.52 to 3.26 Pa） acoustic pressure acting output. This probe structure is easy to form FBG hydrophone array by multiplexing technique. The research shows that this planar structure not only can form FBG hydrophone probe, but also can constitute optical FBG laser hydrophone probe. The structure can realize different bandwidth, different range acoustic pressure measurement by adjusting the geometrical size of the sheet.     

提高布里渊光时域反射应变仪测量空间分辨力的等效脉冲光拟合法

由于探测光脉冲宽度受到限制,布里渊光时域反射仪(BOTDR)在对光纤上的应变进行分布式测量时,空间分辨力只能达到1 m。针对布里渊光时域反射仪单次采样接收背向布里渊散射信号(BBS)需要一定的时间,提出了基于等效脉冲光的多洛仑兹拟合法以提高其应变测量的空间分辨力。该方法将探测光脉冲在布里渊光时域反射仪完成单次采样所需的时间上进行积分,将积分函数作为等效脉冲光的表达式,再根据等效脉冲光的形状将布里渊光时域反射仪接收到的背向布里渊散射谱(BBS)细分,并对它进行多洛仑兹迭代拟合,准确求得每个细分布里渊散射谱的中心频率,进而利用光纤中布里渊频移与应变的对应关系,得到光纤中与细分布里渊散射谱对应的细分光纤单元上的应变情况。实验结果表明,利用这种方法,可使布里渊光时域反射仪应变测量的空间分辨力提高至0.05 m。     

溶胶-凝胶SiO2薄膜氨热两步后处理

 以正硅酸乙酯为前驱体,氨水作催化剂,采用溶胶-凝胶法提拉镀制SiO₂双面膜,对薄膜进行氨处理和热处理。采用椭偏仪、分光光度计、红外光谱、扫描探针显微镜、静滴接触角测量仪表征薄膜的特性。研究表明：经氨热两步后处理,膜厚持续减小,折射率经氨处理先增大了0.236,再经热处理又减小了0.202,膜层透光性变好,透过率峰值持续向短波方向移动;经两步后处理的膜面平整度明显变好,与水的接触角先增大到58.92°后减小到38.07°。     

基于CRISPR/Cas技术的传染性病原精准便携化检测系统

以核酸为检测靶向的分子诊断方法是传染性病原体检测的金标准,但将其应用于便携化或现场快速诊断时仍存在多种限制和挑战,如特异性差、操作繁琐和便携化难等。规律间隔成簇短回文重复序列（CRISPR）/CRISPR相关蛋白（Cas）-荧光检测方法有望大幅提升核酸识别的特异性和信噪比。本研究开发了环介导等温扩增（LAMP）-CRISPR/Cas-便携化灰度读取仪检测系统。在CRISPR RNA (crRNA)存在下,利用CRISPR/Cas12a体系实现了对自主设计的甲型和乙型流感病毒核酸LAMP扩增反应体系的精准荧光检测,验证了CRISPR/Cas体系的高选择性和通用性。配套自主开发的便携化灰度读取仪,可同时实现荧光信号的低成本采集和高可靠性可视化判读,检测结束后直接输出样品的阳/阴性结果。利用本检测系统对实际样本进行了分析,验证了其可靠性和实用性,证明了本系统能够实现流感病毒的高灵敏、高特异性便携化分析。     

全张量SQUID磁梯度计在航空磁测方面的应用研究

航空磁测在矿产资源勘探、地球物理、科学研究以及军事应用等方面应用甚广。文中对超导量子磁力仪在航空磁测的应用研究情况进行了综述,简要介绍了SQUID磁强计与梯度计的差别。最后介绍了构成全张量超导磁探仪的两种方法,分析了两种方法的磁梯度不平衡度以提高航空磁测的实用性。     

ADS注入器ⅡCry Module的低温准直测量技术

作为ADS注入器Ⅱ的关键元件,Cry Module由于其无法通视和超低温特性,是超导直线加速器准直中的重点与难点.提出由激光跟踪仪和测微准直望远镜协同准直冷质量组件.设计测微准直望远镜所用十字丝目标及其支架.成功安装冷质量组件,监测了两次低温实验时的位移.常温安装精度达到0.15mm,低温监测精度达到0.5mmm.目前ADS-Cry Module已通过专家组的水平测试验收,技术指标优于国际上的最好水平.