Control of LHCD on the HL-2A Tokamak

in order to study non-indutive plasma current production, the lower hybrid current drive（LHCD） experiment on the HL-2A tokamak is carried out. Simultaneously a microcomputer has been used to control the whole LHCD system. During the experiment this year, we can monitor and protect the LHCD system by use of the microcomputer control system, which will imediately switch off the microwave power to be launched into the tokamak if the plasma is disrupted. All this ensure that the microwave is injected into the equipment correctly.     

High Voltage Pulse Power and the Technics for the Capacitor Power-Storage Type

Lower hybrid wave （LHW）, electro cyclotron （EC） and neutral beam injection （NBI） etc. are the important methods of auxiliary heating. They would be devoted to the HL-2A tokamak step by step. In order to satisfy the debug of each system and the need of the experiment, the system should be equipped with high voltage pulse power （HVPP） according to the requirement.     

三层同轴液柱内的热毛细对流的近似解析解

1引言在微重力下用浮区法生长高质量、大体积单晶体是一种很有应用前景的方法，但热毛细对流所引起的诸如宏观不均匀性、生长条纹等缺陷严重限制了这一方法的应用。目前，人们试着用液封方法抑制热毛细对流。文献［1～3］分别对两层流体系统内的热毛细对流所作的研究表明：通过液封，被封层内的热毛细对流可以得到显著抑制。本文对圆柱三层流体系统内的热毛细对流进行研究，为热毛细对流规律的揭示以及进一步总结出其控制方法提供了理论数值依据。2控制方程和边界条件考虑长为L的互不溶混的三层轴对称同轴液柱，如图1所示，两端壁保持定温T…     

2,2—二（4—甲氧基苯基）—1,1—二氯乙烯的显色反应及应用研究

本文对2,2-二(4-甲氧基苯基)-1,1-二氯乙烯(简称DMDE)与H_2SO_4显色反应的机理进行了探讨,证实了该反应为可逆反应,其显色产物与亲电加成反应的中间体有关;并利用该反应建立了甲氧基氯原药和乳油中DMDE含量的分光光度测定方法。实验表明:DMDE在0～27.5μg/10ml范围内服从比耳定律,其表观摩尔吸光系数ε为2.56×10~4L·mol~(-1)·cm~(-1)。应用该法对甲氧基氯原药和乳油进行了分析,获得满意结果。     

Theoretical and experimental studies on a compact stretcher with large spectral bandwidth and high transmission efficiency

To ensure safe and effective amplification for the chirped pulse amplification laser facility, many factors such as pulse spectral width, pulse duration, grating parameters and incidence angle parameter are considered carefully in the design of the pulse stretcher. A compact four pass Offner stretcher design is given out. Experiment results show that the stretcher has broad spectral width, large stretching ratio and high transmission efficiency. By comparison, the calculated result of the dispersion effect on the pulse duration is completely consistent with the experiment result.     

Research on Lateral Vibration Coupling Mechanism of a High-Speed Train Based on Singular Coefficients

Russian Physics Journal - The lateral vibration coupling mechanism is the basic law describing the current vibration behavior of a high-speed train. The main reason is that there are design defects...     

Time-resolved shadowgraphs of material ejection in intense femtosecond laser ablation of aluminum

The dynamic process of intense 50 fs laser ablation of aluminum is investigated by ultrafast time-resolved microscopy. A stripe pattern preceding phase explosion is clearly seen in the shadowgraph of 1 ns time delay. Intermittent material ejections are observed within the ejected plume after 2.5 and 7 ns time delay, respectively, which may be attributed to the material response to the generation of an extremely strong thermoelastic wave. Similar processes are also recorded in the ablation of silicon and glass samples, except for the glass samples, the intermittent material ejections are not found.     

High‐Quality Three‐Dimensional Nanoporous Graphene

We report three‐dimensional (3D) nanoporous graphene with preserved 2D electronic properties, tunable pore sizes, and high electron mobility for electronic applications. The complex 3D network comprised of interconnected graphene retains a 2D coherent electron system of massless Dirac fermions. The transport properties of the nanoporous graphene show a semiconducting behavior and strong pore‐size dependence, together with unique angular independence. The free‐standing, large‐scale nanoporous graphene with 2D electronic properties and high electron mobility holds great promise for practical applications in 3D electronic devices.     

Strong and Superhydrophobic Wood with Aligned Cellulose Nanofibers as a Waterproof Structural Material†

Lightweight structural materials are important for the energy efficiency of applications, particularly those in the building sector. Here, inspired by nature, we developed a strong, superhydrophobic, yet lightweight material by simple in situ growth of nano‐SiO₂ and subsequent densification of the wood substrate. In situ generation of SiO₂ nanoparticles both inside the wood channels and on the wood surfaces gives the material superhydrophobicity, with static and dynamic contact angles of 159.4^o and 3^o, respectively. Densification of the wood to remove most of the spaces among the lumen and cell walls results in a laminated, dense structure, with aligned cellulose nanofibers, which in turn contributes to a high mechanical strength up to 384.2 MPa (7‐times higher than natural wood). Such treatment enables the strong and superhydrophobic wood (SH‐Wood) to be stable and have excellent water, acid, and alkaline resistance. The high mechanical strength of SH‐Wood combined with its excellent structural stability in harsh environments, as well its low density, positions the strong and superhydrophobic wood as a promising candidate for strong, lightweight, and durable structural materials that could potentially replace steel.