Multi-Channel FIR Laser Interferometer on the HL-2A Tokamak

In recent years, the high density plasma in the range of 10^19～ 10^20m^-3 have been operated in large or middle tokamak device in the world. A muhichannel far infrared interferometer for profile measurement of plasma density on HL-2A divertor tokamak is being developed, however the design of the interferometer will appear many new problem in face of experimental environment of the HL-2A divertor device, such as how to make both transmission and arrangement of optics of the interferometer, the effect of electromo- tive force on device and how about the vibration etc. According to the eight windows setting on the largest flange of the device we have to design a Michelson-type FIR laser interferometer with 8 probing channels and eight concave mirrors must be attached it to the inner wall of the vacuum vessel of the device. Therefore, there are many problems should be taken into account to resolve, for example, （ 1 ） the vibration-proof consider for muhichannel interferometer and HCN laser, （2） the stabilization and reliability of the mirror frame uum vessel, the mirrors, hanging on internal wall of vachow to prevent the sputtering to （3） the vacuum seal of the windows and the design of mobile seal for the shutter to avoid the sputter coating of plasma,     

Thermal stability and frequency up-conversion properties of Er3+-doped oxyfluoride tellurite glasses

The thermal properties of 68TeO2-15BaF2-5SrF2-10LaF3-2KF glass were measured by different temperature analysis (DTA). Up-conversion luminescence of Ers+ ion in the obtained glass was investigated.Mechanism of up-conversion emission was discussed. The result shows that the obtained oxyfluoride tellurite glass 68TeO2-15BaF2-5SrF2-10LaF3-2KF has a good thermal stability (△T = 153.6 ℃) and strong up-conversion green emissions around 527 nm and 549 nm and red emission at 660 nm. This glass can be a promising host material for up-conversion fiber lasers.     

HL—1M装置等离子体中类锯齿电子密度振荡

在欧姆放电和低杂波电流驱动（ＬＨＣＤ）及激光吹气注入杂质的联合实验中,首次在ＨＬ－１Ｍ 装置上观测到了与软Ｘ射线对应得非常好的锯齿型密度振荡。这种类锯齿型的密度振荡存在于低杂波电流驱动与激光吹气等离子体中。分析表明,该锯齿不是通常的ｑ ＝ １ 有理面上的锯齿,而是在低杂波与杂质共同作用下产生的类锯齿型的密度振荡。一种可能的机制是低杂波电流驱动下杂质的中心积累及崩塌引起的扰动磁场导致了快电子的损失,从而使得密度发生振荡     

一种处理远红外激光干涉仪相移信号的新方法

一、引言 在等离子体物理实验中,电子密度的获取十分重要。对于中小型托卡马克装置,其密度范围正好在HCN远红外激光干涉仪(波长337μm)的可测范围,国内外许多装置都用HCN激光干涉仪来测其电子密度n_e。测量来自于干涉仪的两路信号—探测信号V_D和参考信号V_R之间的相位差即可得到n_e。密度相移信号的产生及与n_e的对应关系、传统测量相位差的方法已有专文叙述。传统处理方法由于存在相移过2π时计数值的跳变问题,在密度起伏较频繁     

氰化氢激光干涉仪测量HL-1装置等离子体电子密度

本文叙述在HL-1装置上为测量平均电子密度n_e(i)而建立的,长探测臂迈克尔逊(Michelson)型转动光栅调相式氰化氢激光干涉仪(长臂HCN激光干涉仪)及其实验结果。并采用Apple-Ⅱ微机对密度数据进行实时处理,在脉冲送气实验中和破裂不稳定性发生时,观测了电子密度变化。本实验在电子密度(1—3)×10~(13)cm~(-3)范围内的测量误差约为(4—10)％。     

Electroactive Metal–Organic Frameworks as Emitters for Self‐Enhanced Electrochemiluminescence in Aqueous Medium

Metal–organic frameworks (MOFs) have limited applications in electrochemistry owing to their poor conductivity. Now, an electroactive MOF (E‐MOF) is designed as a highly crystallized electrochemiluminescence (ECL) emitter in aqueous medium. The E‐MOF contains mixed ligands of hydroquinone and phenanthroline as oxidative and reductive couples, respectively. E‐MOFs demonstrate excellent performance with surface state model in both co‐reactant and annihilation ECL in aqueous medium. Compared with the individual components, E‐MOFs significantly improve the ECL emission due to the framework structure. The self‐enhanced ECL emission with high stability is realized by the accumulation of MOF cation radicals via pre‐reduction electrolysis. The self‐enhanced mechanism is theoretically identified by DFT. The mixed‐ligand E‐MOFs provide a proof of concept using molecular crystalline materials as new ECL emitters for fundamental mechanism studies.     

The diffusion coefficient of H2S in liquid sulfur

The diffusion coefficient of H₂S in liquid sulfur is a key kinetic parameter that has been missing in literature. In this paper, a pressure decay method was applied to measure the diffusion coefficients of H₂S in liquid sulfur at 403 and 423 K. This pressure decay process was then modeled by taking the simultaneous diffusion and reversible chemical reactions between H₂S and liquid sulfur into consideration. The diffusion coefficients and reaction rate constants were numerically determined by fitting theoretical curves to experimental data using Finite Element Method and Genetic Algorithm. The solubility of H₂S in liquid sulfur at 403 and 423 K was also calculated and the results agreed with the semi-empirical correlation lately reported in literature. This study further extended the validity of the correlation to higher partial H₂S pressure conditions.     

MCM-41担载的镍钼硫化物上二苯并噻吩的加氢脱硫反应动力学

 采用高压滴流床反应器研究了在WHSV＝30~90 h-1,p＝5.0 MPa和θ＝280~340 ℃的条件下,二苯并噻吩(DBT)在不同Ni含量的Ni-Mo/MCM-41催化剂样品上的加氢脱硫(HDS)反应动力学. 应用拟1级活塞流模型计算了该系列催化剂上的HDS反应的表观反应速率常数以及加氢反应路径和氢解反应路径的反应速率常数. 结果表明,加氢反应路径的速率常数和氢解反应路径的速率常数在同一个数量级上,说明在Ni-Mo/MCM-41上进行DBT的HDS反应时, 这两个平行的反应路径是并重的. 随着催化剂中Ni/Mo原子比的增大,两个反应路径的速率常数均增大,并在Ni/Mo原子比为0.75时达到最大值. 当Ni/Mo原子比增大到1.0时,两个反应路径的速率常数均大幅下降. 根据Arrhenius方程求得了DBT在Ni-Mo/MCM-41上进行HDS反应的表观活化能. 结果表明,催化剂的活性与表观活化能存在明显的相关关系,活化能越低,活性越高.     

Electrostatic Shielding Boosts Electrochemical Performance of Alloy-Type Anode Materials of Sodium-Ion Batteries

The applications of alloy-type anode materials for Na-ion batteries are always obstructed by enormous volume variation upon cycles. Here, K⁺ ions are introduced as an electrolyte additive to improve the electrochemical performance via electrostatic shielding, using Sn microparticles (μ-Sn) as a model. Theoretical calculations and experimental results indicate that K⁺ ions are not incorporated in the electrode, but accumulate on some sites. This accumulation slows down the local sodiation at the “hot spots”, promotes the uniform sodiation and enhances the electrode stability. Therefore, the electrode maintains a high specific capacity of 565 mAh g⁻¹ after 3000 cycles at 2 A g⁻¹, much better than the case without K⁺. The electrode also remains an areal capacity of ≈3.5 mAh cm⁻² after 100 cycles. This method does not involve time-consuming preparation, sophisticated instruments and expensive reagents, exhibiting the promising potential for other anode materials.