Coupled radiotracer and voltammetric study of the adsorption of 1-hydroxy-ethane-1,1-diphosphonic acid on polycrystalline gold

Coupled application of a version of the in-situ radiotracer ‘foil’ method and voltammetry provided information on the time-, potential-, concentration- and pH-dependent adsorption of 1-hydroxy-ethane-1,1-diphosphonic acid (HEDP) on a polycrystalline gold electrode, and on the effect of Zn²⁺ ions on the adsorption phenomena. Adsorption processes on the oxide-free surface of gold were observed to be potential-dependent in the potential range 0.05–1.00 V (versus RHE), while formation and irreversible accumulation of oxidation products of HEDP could be detected at E>1.00 V. The relative adsorption strength of HEDP (its dissociation and/or oxidation products) was found to be higher on an oxide-free gold surface than on an oxide-covered one. The surface excess of HEDP increased with increasing pH. Addition of Zn²⁺ ions to the solution exerted a substantial effect on the HEDP accumulation. Namely, significant differences in the surface coverage, as well as in the kinetics and mechanism of HEDP adsorption could be detected in the potential regions below and above E=0.2 V. Reduction of Zn(II) species at E≤0.1 V is probably coupled with the induced adsorption of HEDP on an Au electrode, leading to the formation of a polymolecular HEDP–Zn surface complex layer.     

Bunch compression study using the envelope model in CSRm

The feasibility of attaining a short-pulse-duration heavy ion beam with a nanosecond pulse length is studied in the main ring of the Heavy Ion Research Facility in Lanzhou (HIRFL). Such a heavy ion beam can be produced by non-adiabatic compression, and it is implemented by fast rotation in the longitudinal phase space. In this paper, the possible beam parameters during longitudinal bunch compression are studied by using the envelope model. The result shows that a shortest heavy ion bunch ²³⁸U²⁸⁺ of 29 ns with energy of 200 MeV/u can be obtained, which can satisfy high energy density physics research.     

核磁共振磷谱在羟基亚乙基二磷酸合成中的应用

讨论了羟基亚乙基二磷酸的反应机理,并通过核磁共振磷谱对合成反应过程中的中间体亚磷酸和关键中间体(3)的实时监测．在此基础上优化了反应条件．最后,对原料三氯化磷中的杂质进行合理分析和排除．     

离子色谱法同时测定3种有机膦酸类阴垢缓蚀剂

建立了同时测定有机膦酸类阻垢缓蚀剂羟基亚乙基叉二膦酸（HEDP）、氨基三甲叉膦酸（ATMP）和乙二胺四亚甲基膦酸钠（EDTMPS）的离子色谱检测方法.该方法以Shodex IC NI-424为阴离子交换柱,4 mmol·L^-1 H₂SO₄为流动相,流速为1.0 mL·min^-1,非抑制电导进行检测,方法的线性范围为5~200 mg·L^-1,HEDP、ATMP和EDTMPS的平均加标回收率分别为101.15%、95.48%和92.41%,检出限分别为0.80、4.30和4.27 mg·L^-1;对50 mg·L^-1标准溶液分别进行8次平行测定,相对标准偏差（RSD%）分别为0.83,1.91和1.18.该方法具有简单、快速、灵敏、抗干扰等优点,用于HEDP、ATMP和EDTMPS的质量监控,结果令人满意.     

A study on electroplating of zinc nickel alloy with HEDP plating bath

The electroplating of bright Zn-Ni alloy process using HEDP as coordinating agent, ZNP as additive agent is studied. The effect of coordinating agent, chloride content, [Zn²⁺]/[Ni²⁺], cathode current density, temperature, and supplementary coordinating agent on Ni content is investigated; composition and physical phase of alloy plating layer, brightness of plating layer, and stability of plating solution are comprehensive considered; and also, the optimum composition of plating solution for bright Zn-Ni alloy electroplating and technological condition is determined; finally, deposition mechanism is discussed. Published in Russian in Elektrokhimiya, 2006, Vol. 42, No. 1, pp. 25–30. The text was submitted by the authors in English.     

A design of a two-dimensional,supersonic KH experiment on OMEGA-EP

An experiment meant to investigate the evolution of single mode Kelvin–Helmholtz (KH) instability in the supersonic regime is presented and theoretically analyzed. This experiment is intended to provide a direct measurement of the two-dimensional vortex evolution so that the high-Mach-number effects can be measured. The proposed design takes advantage of the ability of OMEGA-EP to drive experiments for up to 30 ns to produce steady conditions for KH that endure long enough to observe substantial growth. KH growth for the proposed design has been analyzed using two-dimensional numerical simulations. The results were compared to synthetic temporal KH numerical simulations using non-dimensional scaling in the low and high Mach number regime. The comparisons show that the growth in the high Mach number regime is expected to be suppressed by up to a factor of two. The effects of two-dimensional rarefactions from the lateral boundaries of the experimental system were also investigated. It was found that they introduce no major uncertainties or hazards to the experiment. We produced simulated radiographs, which show that the proposed experimental system will enable observation of the KH structures. An experiment of this kind has not yet been performed, and therefore would serve to validate numerical results and analytical models presented here and in the literature.     

EIS characterization of the evolution of calcium carbonate scaling in cooling systems in presence of inhibitors

Electrochemical impedance spectroscopy (EIS) was used to assess the relative effects of scaling and corrosion for steel electrodes in cooling water media and to obtain information on corrosion inhibition and scale inhibition properties of 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP) and hydroxyphosphonoacetic acid (HPA). Steel electrodes were preliminary scaled with CaCO₃ in simulated cooling water and then immersed in the characterization solution. Analysis of the impedance spectra with a simple model allowed following of the time evolution of physical parameters corresponding to the calcium carbonate islands and to the corrosion products accumulated in areas not covered by the scale. In uninhibited solutions, the main effect was the progressive deposit of corrosion products with no additional scaling and little restructuring of the initial carbonate islands. When the solution contained HEDP alone, part of the initial scale was detached from the surface, but the presence of HPA or the mixture HPA+HEDP only induced structural modifications of the initial scale. Moreover, the impedance analysis also showed that HPA exhibited better corrosion inhibition properties than HEDP.     

Nanofluorides

The present review article covers major aspects of inorganic chemistry of nanofluorides, including methods of their synthesis (thermolysis of the precursors, co-precipitation from solutions, reversed micelle technique, hydro- and solvo-thermal techniques, sol–gel method, etc.), nanochemical effects (enhanced chemical activity, self-organization and self-assembly, non-classical mechanism of the single crystal growth, synthesis of non-equilibrium phases), targeted preparation of 1D, 2D, and 3D nanostructures, surface modification of the nanoparticles, fluoride nanocomposites (glass- and nano-ceramics) as well as applications of nanofluorides.