Facile synthesis of a porous network-like silver film for electrocatalytic detection of nitrate

We have developed a method for in-situ construction of a porous network-like silver film on the surface of a glassy carbon electrode (GCE). It is based on a galvanic replacement reaction where a layer of copper nanoparticles is first electrodeposited as a sacrificial template. The silver film formed possesses a porous network-like structure and consists of an assembly of numerous nanoparticles with an average size of 200 nm. The electrode displays excellent electrocatalytic activity, good stability, and fast response (within 2 s) toward the reduction of nitrate at a working potential of −0.9 V. The catalytic currents linearly increase with the nitrate concentrations in the range of 0.08–6.52 mM, with a detection limit of 3.5 μM (S/N = 3) and a repeatability of 3.4 % (n = 5).

A facile method was developed for in situ construction of a porous network-like Ag film on a glassy carbon electrode by a galvanic replacement reaction, where a layer of Cu nanoparticles previously electrodeposited as a sacrificial template. Thus-formed Ag film displays excellent electrocatalytic activity, good stability, and fast response (within 2 s) toward nitrate reduction.

     

The propagation and deposition of fast muons in dense DT mixture

The propagation of the fast muon population mainly due to collisional effect in a dense deuterium--tritium (DT for short) mixture is investigated and analysed within the framework of the relativistic Fokker--Planck equation. Without the approximation that the muons propagate straightly in the DT mixture, the muon penetration length, the straggling length, and the mean transverse dispersion radius are calculated for different initial energies, and especially for different densities of the densely compressed DT mixture in our suggested muon-driven fast ignition (FI). Unlike laser-driven FI requiring super-high temperature, muons can catalyze DT fusion at lower temperatures and may generate an ignition sparkle before the self-heating fusion follows. Our calculation is important for the feasibility and the experimental study of muon-driven FI.     

Simultaneous determination of trace levels of lead(II) and copper(II) by square wave stripping voltammetry using a glassy carbon electrode modified with hierarchical gold dendrites

A glassy carbon electrode was modified with gold hierarchical dendrites (Au HDs) by one-step electrodeposition in the presence of cytosine, which plays an important role in the formation of the Au HDs. This approach is simple, fast, feasible, controllable, without any seed, template, or surfactant. The modified electrodes were used for the simultaneous determination of Pb²⁺ and Cu²⁺ by square wave stripping voltammetry. The peak currents show good linear relationship with concentrations of Pb²⁺ and Cu²⁺ in the range of 5.0 to 15.0 μM. The recoveries of the spiked water samples are in the range of 94.0 %–107.4 % for Pb²⁺ and Cu²⁺, and their relative standard deviation are in the range of 2.7 %–4.3 % for Pb²⁺ and Cu²⁺, respectively (n?=?3).

高能离子在稠密等离子体中的传输和能量沉积

用相对论福克-普朗克方程对高能离子在稠密氘氚等离子体中的碰撞动力学进行了研究，用球谐函数来展开方程的解：格林函数，然后简明地求出了不同能量质子和α粒子在等离子体中的停止时间、减速距离、纵向弥散距离和横向偏转距离.与以前研究离子在等离子体中运动的方法相比，没有假设高能离子在等离子体中损失能量远远小于入射离子能量，求解了纵向弥散距离；并且可以求解横向偏转距离.这些计算对实验上用高能离子加热冷的稠密等离子体，然后进行科学研究具有指导作用，并且可以用来研究快点火的可能性. 关键词： 高能离子 福克-普朗克方程     

Facile synthesis of a porous network-like silver film for electrocatalytic detection of nitrate

We have developed a method for in-situ construction of a porous network-like silver film on the surface of a glassy carbon electrode (GCE). It is based on a galvanic replacement reaction where a layer of copper nanoparticles is first electrodeposited as a sacrificial template. The silver film formed possesses a porous network-like structure and consists of an assembly of numerous nanoparticles with an average size of 200 nm. The electrode displays excellent electrocatalytic activity, good stability, and fast response (within 2 s) toward the reduction of nitrate at a working potential of ?0.9 V. The catalytic currents linearly increase with the nitrate concentrations in the range of 0.08–6.52 mM, with a detection limit of 3.5 μM (S/N?=?3) and a repeatability of 3.4 % (n?=?5).

Proton Acceleration with Nano-Scale Micro-Structured Target by Circularly Polarized Laser Pulse

Two dimensional particle-in-cell simulations are taken to study the interaction of a circularly polarized laser pulse with a nano-scale micro-structured target. The protons which are doped in the rear side of the target experience the electrostatic fields caused by both the radiation pressure driven shock and the target normal sheath at the rear side of the target. A quasimonoenergetic proton bunch with central energy of about 11MeV and energy spread of ＆#8710; ε/ε about 0.18 is achieved by using a 3.45×1019 W/cm2, 66fs laser pulse. A comparison with the case of linearly polarized laser pulse and the same target condition is considered.     

Energetic-ion generation by the combination of laser pressure and Coulomb explosion

A scheme of generating energetic ions by the interaction of an ultrahigh-intensity laser pulse and a thin solid foil is studied. The combination of the effects of radiation pressure and Coulomb explosion makes the ion acceleration more effective. The maximum ion velocity variation with time is predicted theoretically while the temporal evolution of the electrostatic field due to the Coulomb explosion is taken into consideration. Two-dimensional particle-in-cell simulations are done to verify the theory.