[en] The thiosulfate method is a cyanide-free hydrometallurgical method for gold extraction, but the existence of copper ion in Cu²⁺–NH₃–S₂O₃^2- system is not conducive to the subsequent gold(I) recovery. This paper describes a process for improving the gold(I) adsorption capacity of mercapto-functionalized silica gel (MP-SG) by using ethylenediamine (en) as an additive to mask copper(II). The effects of en/Cu²⁺ molar ratio, contact time, and pH on adsorption were investigated. The results showed that the addition of en increased the adsorption capacity of MP-SG to gold by more than 70%. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) confirmed that the valence states of gold and copper on the adsorbent were both + 1, which confirmed the occurrence of competitive copper(II) adsorption. This could be inhibited by the addition of en without affecting the interfacial properties of MP-SG. UV–vis spectroscopy and the distribution of copper species revealed that addition of en changed the composition of the solution, forming a more stable Cu(en)₂²⁺ complex, the fraction of Cu(en)₂²⁺ increased with en content, thus reducing the competitive adsorption of Cu(II) to gold (I). The recovery rate of gold in the actual thiosulfate leaching solution was up to 92.35%, and en has almost no influence on the recycling process of the recovered leaching liquor, which proves the feasibility of this method in practical application. (author)

[en] The absorption of neutral beam power and the fast ion stored energy in EAST plasmas with neutral beam injection (NBI) is analyzed to improve the calculation of thermal energy confinement time. The neutral beam power absorption and fast ion stored energy are systematically calculated using the TRANSP code, through the investigation of global parameters including plasma current, line averaged density and beam energy. Results have shown that scaling laws for the NBI absorption coefficient and fast ion energy rate are obtained through statistical analysis. A comparison of the confinement improvement factor $H_{98y2}$ with these new scaling laws against those assuming fixed coefficients is given. (paper)

[en] A new edge tangential multi-energy soft x-ray (ME-SXR) diagnostic with high temporal (≤ 0.1 ms) and spatial (∼1 cm) resolution has been developed for a variety of physics topics studies in the EAST tokamak plasma. The fast edge electron temperature profile (approximately from $r/a\sim <!--\; ???\; -->0.6$ to the scrape-off layer) is investigated using ME-SXR diagnostic system. The data process was performed by the ideal ‘multi-foil’ technique, with no priori assumptions of plasma profiles. Reconstructed ME-SXR emissivity profiles for a variety of EAST experimental scenarios are presented here for the first time. The applications of the ME-SXR for study of the effects of resonant magnetic perturbation on edge localized modes and the first time neon radiating divertor experiment in EAST are also presented in this work. It has been found that neon impurity can suppress the 2/1 tearing mode and trigger a 3/1 MHD mode. (paper)

[en] Highlights: • Parallel plasma equilibrium reconstruction using GPU for real-time control on EAST. • Vertical control using Bang-bang + PID method to improve the response and minimize the oscillation caused by the latency. • Quasi-snow flake divertor plasma configuration has been demonstrated on EAST. - Abstract: In order to improve the plasma control performance and enhance the capability for advanced plasma control, new algorithms such as PEFIT/ISOFLUX plasma shape feedback control, quasi-snowflake plasma shape development and vertical control under new vertical control power supply, have been implemented and experimentally tested and verified in EAST 2014 campaign. P-EFIT is a rewritten version of EFIT aiming at fast real-time equilibrium reconstruction by using GPU for parallelized computation. Successful control using PEFIT/ISOFLUX was established in dedicated experiment. Snowfldivertor plasma shape has the advantage of spreading heat over the divertor target and a quasi-snowflake (QSF) configuration was achieved in discharges with I_p = 0.25 MA and B_t = 1.8T, κ∼1.9, by plasma position feedback control. The shape feedback control to achieve QSF shape has been preliminary implemented by using PEFIT and the initial experimental test has been done. For more robust vertical instability control, the inner coil (IC) and its power supply have been upgraded. A new control algorithm with the combination of Bang-bang and PID controllers has been developed. It is shown that new vertical control power supply together with the new control algorithms results in higher vertical controllability.