甘肃滴水山金矿床原生晕特征及深部成矿预测

滴水山金矿床是一个主要赋存于滨海—浅海相中酸性火山碎屑岩中,与脆—韧性剪切带有关的蚀变岩型金矿床。在野外地质工作的基础上,对Au2号矿体不同勘探线钻孔中所采样品进行微量元素分析,并利用地质和数学分析方法,对微量元素的空间分布特征、原生晕特征及元素组合特征进行了分析。结果表明:根据格里戈良分带指数法,141号勘探线原生晕轴向分带序列为(Pb-As)-Au-Cu-Zn-Bi-Hg-Sb-Ag-Mo,175号勘探线分带序列为(Hg-As-Au-Sb-Pb-Cu)-Zn-Mo-Ag-Bi,存在前缘晕、近矿晕、尾晕元素重叠的现象;通过相关分析、聚类分析和因子分析,认为Au2号矿体中与Au关系较密切的元素为Ag,其次为As和Sb,并确定了Au元素所在的F1主因子元素组合Sb-As-Ag-Cu-Au-(Pb-Zn)为成矿最有利的元素组合。根据元素分布特征,对深部成矿进行了预测,认为Au2号矿体深部仍有较好的成矿前景。     

One-pot synthesis of PdZnO/C by microwave sintering method as an efficient electro catalyst for ethanol oxidation reaction

The PdZnO/C catalytic material for ethanol oxidation reaction is prepared by microwave heating-glycol reduction method. PdZnO is well polymerized and dispersed on XC72. The results demonstrate that PdZnO/C has better electro catalytic activity and stability for ethanol oxidation reaction than Pd/C at room temperature. ZnO/C shows no catalysis for ethanol oxidation. The oxidation peak potential of PdZnO/C electrode is shifted negatively to 0.21 V. The current density of PdZnO/C electrode is 145 mA cm⁻², while that of the Pd/C electrode is 60 mA cm⁻². Moreover, single cell discharge test shows that discharge voltage of the PdZnO/C electrode reaches to 0.41 V at 30 mA cm⁻². In summary, ZnO as a co-catalyst significantly improves the activity of PdZnO/C catalyst for ethanol oxidation reaction.     

Investigation of the charge/discharge characteristics of aqueous zinc–ferric chloride batteries

In a Zn–FeCl₃ battery, zinc granules were used as the anode and ammonium chloride as the electrolyte in both the anode and cathode zones, with ferric chloride as the active cathode substance and carbon felt as an inert cathode. A PE-01 homogeneous membrane was used as the membrane between the anode and cathode zones, with 100 ml of solution in both the anode and cathode zones. The charge/discharge characteristic of the battery was investigated for various concentrations of ferric chloride and ammonium chloride. At present, there are still some difficulties in using this zinc–ferric chloride battery as a rechargeable battery because zinc cannot be electrodeposited very well. However, it can possibly be used as a fuel cell and the operating lifetime of the fuel cell is very long. The actual energy density of a Zn–FeCl₃ fuel cells is approximately equal to the actual energy density of a Pb–PbO₂ battery. When a mixed solution of 2 M ferric chloride and 2 M ammonium chloride was used in the cathode zone with 4–5 M ammonium chloride in the anode zone, a better discharge characteristic was obtained, with a discharge time of approximately 14–15 h at 5 Ω. The most remarkable advantages for Zn–FeCl₃ fuel cell are that both zinc and ferric chloride are very cheap and environmentally friendly, with flat discharge voltage characteristics.     

旋流雾化水膜除尘器内尘粒运动特性及分离效率

基于气固多相流复杂的运动特征，结合旋流雾化水膜除尘器的特点，同时考虑尘粒碰壁面黏附与反弹条件，颗粒间的碰撞与并聚、喷水加湿对颗粒间并聚及碰撞、颗粒运动特性的影响，并考虑颗粒对气相的作用，构建了描述旋流雾化水膜除尘器内湍流气固多相流的三维时均方程组，模型封闭采用k-ε／RNG模型，数值模拟了旋流雾化水膜除尘器内尘粒运动特性及分离效率。结果表明：在设置水膜除尘器尘粒遇壁面条件时，应设置尘粒碰壁为黏附；除尘器内干段、湿段比例、尘粒粒径、尘粒入口位置等对除尘效率高低均存在影响；壁面水雾膜的黏附及喷水对尘粒并聚影响较大，尘粒在除尘器内运动位移小于尘粒碰壁面反弹及不考虑尘粒并聚的情况，越有利于尘粒分离；除尘器入口速度越大及喉部喷水速度越大，越有利于尘粒的除去。     

Photoluminescence study of Sb-doped ZnO films deposited by a closed tube CVT technique

Sb-doped ZnO film was obtained by CVT technique in a closed tube, and the temperature dependence of its photoluminescence spectrum was also investigated. The Sb-related photoluminescence peaks were observed. The peaks occurred at 3.352, 3.312, 3.240 and 3.168 eV were respectively assigned to the neutral acceptor-bound excition, free electron to acceptor transitions, and the first- and second- longitudinal optical phonon replicas emissions. The acceptor binding energy was determined to be 125 meV, aided by free electron to acceptor transition.     

Thin-film transistors with sol-gel deposited Mg0.1Zn0.9O films as active channel layer

We report on field-effect transistors using Mg_0.1Zn_0.9O thin film as channel layer. The effect of Mg is to increase the band gap and decrease the electron carrier concentration. The Mg_0.1Zn_0.9O film deposited by sol-gel method has a highly c-axis orientation and excellent optical properties. The devices display a channel mobility of 0.76 cm² V^− 1 s^− 1 and an on/off ratio of 400.     

Effect of N2O plasma treatment on the improvement of instability under light illumination for InGaZnO thin-film transistors

This paper investigates the impact of N₂O plasma treatment on the light-induced instability of InGaZnO thin film transistors with a SiO₂ passivation layer deposited by plasma-enhanced-chemical-vapor-deposition (PECVD). For the untreated device, because the deposition of the SiO₂ passivation layer by PECVD causes extra trap states, the anomalous subthreshold leakage current can be attributed to a lowering of the source side barrier due to trap-assisted photogenerated holes. In contrast, the N₂O plasma treatment applied to both the gate insulator and the active layer effectively suppresses the device instability under illumination. In order to clarify the influence of the N₂O plasma treatment, this study investigates a device with treatment of only the gate insulator. This device shows a slight decrease of light-induced subthreshold leakage current. This demonstrates that N₂O plasma treatment on IGZO active layer after its deposition is critical in preventing damage from the subsequent SiO₂ passivation deposition process. In addition, the instability of threshold voltage (V_T) under negative bias illumination stress (NBIS) is significantly improved by the N₂O plasma treatment. Furthermore, a different dark recovery rate follows NBIS for untreated and N₂O plasma-treated devices, indicating different hole-trapping levels exist in the energy band.     

Structural and optical properties of Ti-doped ZnO thin films prepared by the cathodic vacuum arc technique with different annealing processes

Highly transparent Ti-doped ZnO thin films were prepared on glass substrates at a deposition rate of approximately 33 nm/min using the cathodic vacuum arc technique with a Zn target power of 550 W and a Ti target power of 750 W, respectively. X-ray diffraction measurements have shown that the Ti-doped ZnO thin film with a vacuum post-annealing condition is c-axis oriented but an amorphous phase at the other post-annealing atmosphere and as-deposited condition. Transmittance measurements show that the best optical quality of the Ti-doped ZnO thin films occurred at a post-annealing atmosphere of N₂/H₂ mixed gases. Additionally, the optical transmittance of all films has been found more than 85% in a range of 500-700 nm. The lowest electrical resistivity was 3.48 × 10⁻³ Ω cm, obtained on as-deposited films. However, the post-annealing condition greatly increased the resistivity.     

A novel approach for the synthesis of nanocrystalline zinc oxide powders by room temperature co-precipitation method

A single step co-precipitation route has been employed for the first time in the preparation of ZnO nanoparticles using ammonium hydroxide and zinc nitrate tetrahydrate. The X-ray diffraction analysis revealed that the synthesized powder has the hexagonal (wurtzite) structure. The as-prepared ZnO powder was well crystalline, without any calcination. This is a promising result compared to those mentioned in the literature, in which crystallization of ZnO nanoparticles was detected at > 300 °C. The average crystallite size of the as-prepared ZnO nanopowder is 20-40 nm. The nanocrystalline ZnO could be sintered to ~ 95% of the theoretical density at 1300 °C in 4 h.     

Phase and morphology controlled synthesis of high-quality ZnS nanocrystals

Through a facile solvothermal method, the controlled preparation of ZnS nanocrystals with different phases and morphologies was achieved only by changing the organic additives. By adding the surfactant of sodium dodecyl benzene sulfonate (SDBS) into the reaction, the cubic heart-like ZnS nanoparticles with uniform size were obtained in a large scale. While, with the assistance of the biomolecule of alginic acid, the pure phase of hexagonal ZnS nanospheres assembled from small ZnS nanoparticles were synthesized. The optical properties of the obtained ZnS nanocrystals were investigated by ultraviolet-visible (UV-vis) absorption and photoluminescence (PL) spectra. The quantum confinement effect could be observed clearly in ZnS nanoparticles.