Anodic stripping voltammetric determination of copper(II) using a functionalized carbon nanotubes paste electrode modified with crosslinked chitosan

The development and application of a functionalized carbon nanotubes paste electrode (CNPE) modified with crosslinked chitosan for determination of Cu(II) in industrial wastewater, natural water and human urine samples by linear scan anodic stripping voltammetry (LSASV) are described. Different electrodes were constructed using chitosan and chitosan crosslinked with glutaraldehyde (CTS-GA) and epichlorohydrin (CTS-ECH). The best voltammetric response for Cu(II) was obtained with a paste composition of 65% (m/m) of functionalized carbon nanotubes, 15% (m/m) of CTS-ECH, and 20% (m/m) of mineral oil using a solution of 0.05 mol L⁻¹ KNO₃ with pH adjusted to 2.25 with HNO₃, an accumulation potential of −0.3 V vs. Ag/AgCl (3.0 mol L⁻¹ KCl) for 300 s and a scan rate of 100 mV s⁻¹. Under these optimal experimental conditions, the voltammetric response was linearly dependent on the Cu(II) concentration in the range from 7.90 × 10⁻⁸ to 1.60 × 10⁻⁵ mol L⁻¹ with a detection limit of 1.00 × 10⁻⁸ mol L⁻¹. The samples analyses were evaluated using the proposed sensor and a good recovery of Cu(II) was obtained with results in the range from 98.0% to 104%. The analysis of industrial wastewater, natural water and human urine samples obtained using the proposed CNPE modified with CTS-ECH electrode and those obtained using a comparative method are in agreement at the 95% confidence level.     

In2O3 + xBaO (x = 0.5-5 at.%) - A novel material for trace level detection of NOx in the ambient

Indium oxide (In₂O₃) doped with 0.5-5 at.% of Ba was examined for their response towards trace levels of NO_x in the ambient. Crystallographic phase studies, electrical conductivity and sensor studies for NO_x with cross interference for hydrogen, petroleum gas (PG) and ammonia were carried out. Bulk compositions with x ≤ 1 at.% of Ba exhibited high response towards NO_x with extremely low cross interference for hydrogen, PG and ammonia, offering high selectivity. Thin films of 0.5 at.% Ba doped In₂O₃ were deposited using pulsed laser deposition technique using an excimer laser (KrF) operating at a wavelength of (λ) 248 nm with a fluence of ∼3 J/cm² and pulsed at 10 Hz. Thin film sensors exhibited better response towards 3 ppm NO_x quite reliably and reproducibly and offer the potential to develop NO_x sensors (Threshold limit value of NO₂ and NO is 3 and 25 ppm, respectively).     

CuO/SnO2-In2O3 sensor for monitoring CO concentration in a reducing atmosphere

The CO sensing property of CuO-loaded SnO₂-In₂O₃ sensor was investigated in a reducing atmosphere. The sensor response to CO for CuO/SnO₂-In₂O₃ (8/2) was much higher than that for CuO/SnO₂ in the range of 200-1000 ppm of CO concentration. Such a high sensor response of CuO/SnO₂-In₂O₃ may originate from the high dispersion of CuO playing a role as sensing site.     

生物分子多巴胺为掺杂剂电化学聚合PPy

根据阴阳离子电荷平衡原理电化学合成多巴胺(DA)掺杂的聚吡咯(Pey)化学修饰电极,利用循环伏安曲线(CV)、红外光谱(FHR)、紫外-可见光谱(UV)对合成产物进行表征,结果表明,生物分子多巴胺有效掺杂进PPy中.通过对PPy/DA化学修饰电极的CV曲线及EIS曲线进行测试发现,掺杂DA后,电极仍具有较好的传输电荷的能力,在此基础上探讨了多巴胺掺杂的原理.     

炭纤维硼改性对其力学性能的影响

采用溶液浸渍对炭纤维（ＣＦ）进行了硼改性处理,并在２５００℃下进行石墨化热处理。研究了硼化物溶液浓度及活化剂对炭纤维力学性能的影响,通过扫描电镜观察炭纤维断面的微观结构形态。实验结果表明,ＣＦ硼处理后可以明显提高纤维的模量,适当控制硼化物溶液浓度,可以同时提高强度。     

Lithium doping and gate dielectric dependence study of solution‐processed zinc‐oxide thin‐film transistors

Abstract— The effects of lithium (Li) doping concentration and gate dielectrics on the performance of solution‐processed zinc‐oxide (ZnO) thin‐film transistors (TFTs) has been investigated. ZnO films with strong c‐axis orientation and lower background conductivity was obtained with 15 at.% of Li. Different crystallization behavior of ZnO was observed in the case of various dielectric surfaces. The 15‐at.% Li‐doped ZnO films (thickness ～20 nm) prepared on SiO² and SiN^x were found to be present in crystalline form, whereas the film prepared on aluminum titanium oxide (ATO) was found to be amorphous. A field‐effect mobility of 1.81 cm²/V‐sec and an Ion/Ioff ratio of 2 × 10⁶ were obtained for the 15‐at.% Li‐doped ZnO TFTs with a bilayer gate dielectric of SiO² and SiN^x. The comparison of dielectric studies showed that the performance of TFTs prepared on SiN^x and ATO are higher than that of the TFTs prepared on SiO².     

5,10,15-三(对氯苯基)20-丙氧苯基卟啉三乙基溴化铵显色剂与铜的显色反应

研究了新显色剂5,10,15三(对氯苯基)20丙氧苯基卟啉三乙基溴化铵与铜的显色反应。结果表明:在中性介质中,沸水浴加热10min形成1:1的络合物,λmax=417nm,在0～12μg/10mL范围内吸光度与铜浓度的关系符合比尔定律,表观摩尔吸光系数ε=3.58×105。该法具有灵敏度高及选择性好的特点,用于水样实际测定,结果满意。     

湿法提铜技术的发展及对铜工业的影响

由于湿法提铜技术具有工艺简单、投资省、成本低 ,可以处理低品位矿和复杂矿等优点 ,近年来得到了迅速的发展 ,已经达到了很大的生产规模和很高的技术水平 ,不仅可以处理低品位矿和氧化矿 ,而且可以处理高品位的硫化矿。本文介绍了世界上湿法炼铜技术最新的进展以及在中国的发展前景。     

江西与浙江铜加工比较分析

本文从对比江西、浙江两省的铜产量和铜加工材产量的现状入手 ,深刻分析了两省在铜加工发展上存在的差别。     

固体废钢脱铜新装置

描述了采用固 /气反应废钢脱铜的原理 ;介绍了实验室和扩大规模脱铜试验装置、有关参数及其操作工艺 ;提供了已经取得的数据 ;指出了尚待解决的问题。