Non-contact thickness measurement for ultra-thin metal foils with differential white light interferometry

A new differential white light interference technique for the thickness measurements of metal foil is presented. In this work, the differential white light system consists of two Michelson interferometers in tandem, and the measured reflective surfaces are the corresponding surfaces of metal foil. Therefore, the measuring result is only relative to the thickness but not the position of metal foil. The method is non-contact and non-destructive, it has the advantages of high accuracy, fast detection, and compact structure. Theoretical analysis and preliminary experimental verifications have shown that the technique can be used to measure the thickness of foil in the range of 1 to 80 μm with accuracy better than 0.08 μm.     

螺旋脉冲形成线实验研究

 设计了一种用于长脉冲功率源研究的Blumlein型螺旋脉冲形成线。该形成线主要是将铜带绕在绝缘衬筒上形成螺旋形结构，以蓖麻油为介质，匝数为3.5匝每m，充电时间为1 μs，负载为电子束二极管。给出了形成线参数的理论计算公式以及实验研究结果。在300 kV脉冲功率源上得到的脉冲延迟为200 ns，特征阻抗约100 Ω，形成的脉冲半高宽为180 ns，前沿15 ns，平顶宽度150 ns。实验证明该螺旋脉冲形成线结构能够有效地延长形成脉冲的宽度。最后分析了开关电感、充电时间以及螺旋形结构对形成线输出脉冲前沿及平顶畸变的影响。结果表明：较小的主开关电感是形成较陡的脉冲前沿的关键，获得好的脉冲波形应选择适当的充电周期，螺旋形结构容易导致色散产生，需要选取适当的螺旋角。     

Calculation of Total Cross Sections for Positron Scattering by Lithium at Intermediate Energies

The total cross sections for positron scattering by lithium at intermediate energies (10-200eV) are calculated by using the coupled-channel optical method with a complex equivalent-local polarization potential which incorporates ionization continuum and positronium (Ps) formation channels contributions into the coupled channels framework. The effects of the two-body Ps rearrangement and three-body ionization process on the total crosss ection are found to be significant at lower energies and this effect is not negligible up to 30 eV. Compared to the available theoretical data, the predicted total cross sections agree quite well with the calculations of McAlinden et al. [J. Phys. B: At. Mol. Opt. Phys. 30 (1997)1543] and Campbell et al. [Nucl. Instrum. Methods Phys. B 143 (199s) 41]     

4-(3-羟基丁氧基)-2-丁醇光学异构体的合成

以廉价易得的(R/S)-3-羟基丁酸甲酯(4a/4b)为起始原料,经过5步反应,以44%~50%的总收率合成了4-(3-羟基丁氧基)-2-丁醇光学异构体1a~1c,为相应的手性新药的开发提供了新途径.     

助剂种类对Cu-MCM-41在苯羟基化反应中催化性能的影响

研究了苯过氧化氢直接羟基化制备苯酚反应中不同种类助剂对高铜含量(最高达26.0%)MCM-41催化性能的影响.结果表明,掺杂酸性助剂B和Al可使苯酚的选择性达到100%,氧化还原性助剂V和Cr可适当提高苯转化率,而Zr和Ti等元素对Cu-MCM-41的催化性能有抑制作用.根据自由基反应机理对不同助剂产生的影响进行了初步分析.     

N-氟代双苯磺酰胺作为氧化剂制备二硫化合物的研究（英文）

建立了一种以N-氟代双苯磺酰胺(NFSI)为氧化剂合成二硫化合物的新方法.该方法反应温和、操作简便、反应时间短并无过度氧化的副产物(亚砜或砜类化合物)生成.     

高等中医药院校《物理化学》网络教学平台的建设与实践

《物理化学》对高等中医药院校药学类专业学生来说,是必需学习和掌握的一门综合性、抽象性和实验性较强的课程,为此建设并开展实施了《物理化学》网络教学平台。该平台主要通过在线学习和在线测试辅助理论课和实验课教学,借助平台可图文并茂地展示复杂的理论知识点,可弥补实验设备条件的不足,更生动、形象、准确地向学生教授知识,具有较强的实用性和人性化特征,对于学生后续专业课程的学习以及培养学生的科研能力等方面发挥积极影响。     

低能O^3＋与H2碰撞电子俘获过程中靶的同位素效应研究

利用全量子的分子轨道强耦合方法，我们研究了基态的O^3＋（2s^22p^2P）与氚分子和氢分子碰撞的电荷转移过程，计算了方位角为45°，能量分别为0．1eV／u，1．0eV／u，100eV／u，500eV／u的单电子俘获的振动分辨的态选择截面及总截面．分子轨道强耦合计算中采用了自旋耦合价带理论计算的三原子分子势能面和径向耦合矩阵元，对体系的电子运动同H2（T2）或H2^＋（T2^＋）的转动和振动之间的耦合，根据能量的不同，分别采用了无限阶的冲量近似或振动冲量近似．结果发现，低能O^3＋与H2碰撞电子俘获过程中靶的同位素效应显著：对不同的同位素靶，单电子俘获的总截面以及振动分辨态选择截面的分布明显不同；入射离子能量越低，同位素效应越显著．     

S波段长脉冲相对论速调管放大器的实验研究

 介绍了S波段强流长脉冲相对论速调管放大器（RKA）的高频系统设计、长脉冲强流相对论电子束(IREB)的调制及微波提取等方面的实验研究结果。重点阐述了长脉冲IREB调制和输出微波中的自激振荡问题。通过采用高阶工作模式以及参差模式设置的谐振腔、提高系统安装的同心度和调节电子束参数等措施，使自激振荡得到了抑制。采用550 kV，4 kA及210 ns的环行电子束，经过优化调节RKA参数，使强流调制电子束流脉宽由50 ns增加到150 ns，同时得到了3.2 kA的基波调制电流。从该RKA得到了峰值功率580 MW、脉宽140 ns的输出微波，束波转换效率26%，增益34 dB。     

M1 transition energy and rate in the ground configuration of Ag-like ions with 62 ≤ Z ≤ 94

Systematic calculations and assessments are performed for the magnetic dipole(M1)transition energies and rates between the ²F^o_5/2,7/2 levels in the ground configuration 4d104f along the Ag-like isoelectronic sequence with 62≤Z≤94 based on the second-order many-body perturbation theory implemented in the Flexible Atomic Code.The electron correlations,Breit interaction and quantum electrodynamics effects are taken into account in the present calculations.The accuracy and reliability of our results are evaluated through comprehensive comparisons with available measurements and other theoretical results.For transition energies,our results are in good agreement with the recent experimental data obtained from the electron beam ion traps within 0.18%.The maximum discrepancy between our results and those obtained with the large-scale multiconfiguration Dirac–Hartee–Fock calculations by Grumer et al.[Phys.Rev.A 89062501(2014)]is less than 0.13%along the isoelectronic sequence.Furthermore,the corresponding M1 transition rates are also reported.The present results can be used as the benchmark and useful for spectra simulation and diagnostics of astrophysical and fusion plasmas.