Substrate temperature-controlled precursor reaction mechanism of PEALD-deposited MoOx thin films

Journal of Materials Science - Molybdenum oxide (MoOx) films had been grown by using plasma-enhanced atomic layer deposition (PEALD) with Mo(CO)6 precursor and O2 plasma reactant in a substrate...     

Comparative study of self-assembling of multilayers using reactive sputter deposition and mass selective ion beam deposition

While experimenting with the growth of metal-containing amorphous carbon (a-c:Me) thin films using two different growth processes, self-assembled multilayered structures were observed. One of the processes is a reactive magnetron sputter deposition process. The other process is a mass selective ion beam deposition process. Despite of the differences in the growth method and the growth condition, self-assembled multilayered thin films, consisting of alternating dark layer and bright layer, were obtained in both processes. Based on the consideration of energy for atomic diffusion in the thin films, the growth mechanism is discussed.     

神经网络极速学习方法研究

单隐藏层前馈神经网络(Single-hidden Layer Feedforward Neural Network,SLFN)已经在模式识别、自动控制及数据挖掘等领域取得了广泛的应用,但传统学习方法的速度远远不能满足实际的需要,成为制约其发展的主要瓶颈.产生这种情况的两个主要原因是:(1)传统的误差反向传播方法(Back Propagation,BP)主要基于梯度下降的思想,需要多次迭代;(2)网络的所有参数都需要在训练过程中迭代确定.因此算法的计算量和搜索空间很大.针对以上问题,借鉴ELM的一次学习思想并基于结构风险最小化理论提出一种快速学习方法(RELM),避免了多次迭代和局部最小值,具有良好的泛化性、鲁棒性与可控性.实验表明RELM综合性能优于ELM、BP和SVM.     

Electrospun ZnO Nanowires as Gas Sensors for Ethanol Detection

ZnO nanowires were produced using an electrospinning method and used in gas sensors for the detection of ethanol at 220 °C. This electrospinning technique allows the direct placement of ZnO nanowires during their synthesis to bridge the sensor electrodes. An excellent sensitivity of nearly 90% was obtained at a low ethanol concentration of 10 ppm, and the rest obtained at higher ethanol concentrations, up to 600 ppm, all equal to or greater than 90%.     

Evaluation of various silver-containing dressing on infected excision wound healing study

Silver-containing dressings have been widely used for controlling wound infection. However, the relationship between different concentrations of silver in dressings and their antimicrobial activities and wound-healing efficacies remains unclear. In the present study, we (in cooperation with Bio-medical Carbon Technology) investigated various silver-containing activated carbon fibers to understand the effects of different silver concentrations on the efficacies of a silver containing dressing. Our results indicated that various silver-containing activated carbon fibers exhibited good antibacterial effects and biocompatibility in terms of cell viability and that silver concentration showed a minor influence on cell growth. The infected excision wound model indicated that compared to silver-containing activated carbon fiber and other commercial silver-containing dressings assisted wound healing by promoting granulation and collagen deposition. Meanwhile, the silver ion can only be restrained in epidermis by intact skin. During application on the wound area, a temporary increase of serum silver can be detected, but this elevated serum silver level decreased to a subtle level after the removal of silver-containing activated carbon fiber.     

Effects of Seed Layer Characteristics on the Synthesis of ZnO Nanowires

Single crystalline zinc oxide (ZnO) nanowires were synthesized on sputter-deposited ZnO seed layers via hydrothermal reactions in an equimolar (20 mM) aqueous solutions of Zn(NO₃)₂·6H₂O and C₆H₁₂N₄ at 90°C. The sputter-deposited ZnO seed layers were prepared to exhibit different crystalline structures in order to examine their effects on the growth of ZnO nanowires. It was found that the nanowire diameter depends on the size of the (002) grains of the seed layer. This is attributed to the epitaxially growth of the nanowires from the columnar grains of the seed layer which is shown by the TEM analysis.     

食品中多溴联苯醚检测技术研究进展

多溴联苯醚是一种持久性环境污染物,在环境介质中广泛分布,可通过食物链富集,对人体健康产生危害,因此建立有效检测食物中多溴联苯醚的方法,对食品安全风险评估具有重要意义。由于多溴联苯醚种类繁多、含量极低以及食品基质的复杂性,研究者们在积极探索简单高效的前处理技术以及高灵敏分析检测方法。本文从食物样品分布、预处理方法及检测技术等方面对这些方法进行简要介绍和比较,为进一步开展食品多溴联苯醚分析研究工作提供理论参考。     

HPLC法测定复方吴茱萸碱纳米乳中吴茱萸碱的含量

目的:建立HPLC法测定复方吴茱萸碱纳米乳制剂中吴茱萸碱含量的方法。方法:采用HPLC法在225 nm波长处测定峰面积,测定复方吴茱萸碱纳米乳中吴茱萸碱的含量。结果:表明吴茱萸碱在225 nm处有最大吸收,浓度在0.52μg·mL至16.64μg·mL-1时与峰面积呈良好的线性关系,回归方程为:A=214.3C-5.943,r=0.9997(n=6);平均回收率为99.31%,RSD为0.74%,符合测定的要求;日内及日间精密度的RSD均小于1%(n=5)。结论:本方法准确度高、专属性好,可用于纳米乳制剂中吴茱萸碱含量的测定。     

Effects of process conditions on the synthesis and microstructure of nano-scale metal-containing amorphous carbon thin films

Thin films of metal-containing amorphous carbon (a-C:Me) were deposited on a number of substrates, including silicon, Pt coated silicon, carbon coated silicon, polymer, and glass. The deposition was performed in a dc reactive sputter deposition system equipped with one single magnetron gun. The gases used were various mixtures of CH4 + Ar. The gas mixture was admitted to the deposition chamber at constant flow rate and ratio. Self-assembled alternating layer structure was observed under certain deposition conditions. Correlation between the self-assembled alternating layer structure and deposition parameters is presented and discussed. The role of carbon energy in the segregation of metal and carbon to form the layer structure is addressed.