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As a new diagnostic method of core electromagnetic field, the laser-driven ion-beam trace probe (LITP), is expected to realize the first application of the advanced laser accelerator in magnetic confinement fusion. The detector of the LITP directly measures the distribution of the dispersed pulsed ions after they have passed through the core plasma (Yang 2014 Rev. Sci. Instrum. 85 11E429). In such an environment of high temperature and radiation, the response and lifetime of the ion detector is very crucial. In this work, we have verified the feasibility of the LITP ion detection through systemic experiments. A CsI(Tl) scintillator coupled with an imaging system composed of optical lens and optical fiber array was calibrated on both the 4.5 MV Electrostatic Accelerator and the Compact LAser Plasma Accelerator (CLAPA) at Peking University. We found that the detectable proton density limit is achievable by using a tens of TW level laser system. The CsI(Tl) scintillator system was also tested on the HL-2A tokamak device to measure the real background noise caused by the hot plasma electrons and radiation. It was not damaged by the harsh environment after being placed in the tokamak for three days, and the background noise was completely suppressed when using an ultrafast camera and microsecond shutter. These calibrations and tests verified the feasibility of the LITP detector.

The lattice parameters, vacancy formation energies, elastic properties, Vickers hardness and electronic structure of ReB2 with lower concentration of boron vacancy are studied using first-principles approach. The lattice parameters and unit-cell volume of ReB2 with boron vacancy rapidly decrease as boron vacancy concentration increase. The calculated vacancy formation energies show that the ReB2 are more stable than that of system with boron vacancy. With increasing boron vacancy, the bulk modulus, shear modulus, Young modulus and Vickers hardness gradually decrease and the boron vacancy results in mechanical transition from brittleness to ductility, which are in good agreement with experimental results. The decreases of elastic modulus and Vickers hardness are originated from the weak hybridization between Re atoms and B atoms in boron vacancy region and forms the weak Re–B bonds and B–B covalent bonds.

Using the density-functional theory calculations, we have investigated the effect of an in-plane electric field on the electronic properties and the structural stability of the edge-oxygenated armchair graphene nanoribbons (AGNRs). It has been found that the metallic-semiconducting transition and band gap modulation can be realized if a proper in-plane electric field is applied across the edge-oxygenated AGNR. Moreover, the critical strength of the applied electric field for the transition from metallic to semiconducting phase decreases with the width of the AGNR, while the range of the applied electric field required to maintain the semiconducting phase is increased when the width of AGNR decreases.

Vertical gradient freeze (VGF) technology grows III-V semiconductor single crystals with a low thermal gradient and in a thermal dynamically stable system. Such materials grown exhibit low dislocation density and low internal stress. VGF technology has reached the stage of commercial production of 6-in. GaAs, 3-in. InP, and 3-in. GaP. In this review, we present the latest developments of these VGF III-V semiconductors, their superior crystal qualities, electrical characteristics, mechanical strengths, and applications in commercial device manufacturing.

a Department of Materials Science, Key Laboratory of Automobile Materials of MOE and State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, People's Republic of China b State Key Laboratory of Advanced Technologies for Comprehensive Utilization of Platinum Metals, Kunming Institute of Precious Metals, Kunming 650106, Yunnan, China c College of Science, Changchun University, Changchun 130022, PR China

The adoption of liquefied petroleum gas vehicles is strongly linked to the break-even distance at which they have the same costs as conventional cars, with very limited market penetration at break-even distances above 40,000 km. Hydrogen vehicles are predicted to have costs by 2030 that should give them a break-even distance of less than this critical level. It will be necessary to ensure that there are sufficient refuelling stations for hydrogen to be a convenient choice for drivers. While additional LPG stations have led to increases in vehicle numbers, and increases in vehicles have been followed by greater numbers of refuelling stations, these effects are too small to give self-sustaining growth. Supportive policies for both vehicles and refuelling stations will be required.

The preparation of BH-1 magnetic liquid is given. It involves three major steps: formation and washing of Fe 3 O 4 , dispersion of Fe 3 O 4 from water phase into oil phase by using oleic acid, and heating of gel-like Fe 3 O 4 aggregate at constant temperature to become BH-1 magnetic liquid. Some properties of BH-1 magnetic liquid have been measured. BH-1 magnetic liquid has a high saturation magnetization and low vapor pressure at room temperature and is stable in performance. It has been used satisfactorily by the 6th research section of BIAA.