Efficient one-pot synthesis of Ag nanoparticles loaded on N-doped multiphase TiO2 hollow nanorod arrays with enhanced photocatalytic activity

The simultaneous Ag loaded and N-doped TiO₂ hollow nanorod arrays with various contents of silver (Ag/N-THNAs) were successfully synthesized on glass substrates by one-pot liquid phase deposition (LPD) method using ZnO nanorod arrays as template. The catalysts were characterized by Raman spectrum, field-emission scanning electron microscopy (FESEM), high-resolution transmission electron microscope (HRTEM), ultraviolet-vis (UV-vis) absorption spectrum and X-ray photoelectron spectroscopy (XPS). The results suggest that AgNO₃ additive in the precursor solutions not only can promote the anatase-to-rutile phase transition, but also influence the amount of N doping in the samples. The photocatalytic activity of all the samples was evaluated by photodegradation of methylene blue (MB) in aqueous solution. The sample exhibited the highest photocatalytic activity under UV light illumination when the AgNO₃ concentration in the precursor solution was 0.03 M, due to Ag nanoparticles acting as electron sinks; When the AgNO₃ concentration was 0.07 M, the sample performed best under visible light illumination, attributed to the synergetic effects of Ag loading, N doping, and the multiphase structure (anatase/rutile).     

Structural,optical, and photocatalytic properties of the spray deposited nanoporous CdS thin films; influence of copper doping,annealing, and deposition parameters

Nanoporous thin films of Cd_1−xCu_xS (0≤x≤0.06) were grown on a heated glass substrate employing a home-made spray pyrolysis technique. The influences of [Cu]/[Cd] and the annealing in the range 300–500 °C on the structural and morphological properties of the films were investigated by X-ray diffraction (XRD), Fourier transformation infrared spectroscopy (FTIR), field emission scanning electron microscope (FE-SEM) and atomic force microscopy (AFM). The influences of Cu doping ratio, solution flow rate, and the deposition time on the optical properties and photocatalytic activity of these films are also reported. The films are of polycrystalline nature and hexagonal structure. Increasing the Cu doping ratio and annealing temperature improve the (1 0 1) preferential orientation. The crystallite size is ranged from 23.82 to 32.11 nm. XRD and FTIR reveal the formation of CdO in the 6% Cu-doped CdS film annealed at 400 °C and in all films annealed at 500 °C. The pure CdS film is of a porous structure and the close-packing and porosity of the films increase with increasing Cu%. Also, the pore diameter can be controlled from 50 to 15 nm with the increase of Cu content. The films showed transmittance below 70%. The optical band gap of the films is decreased from 2.43 to 1.82 eV with increasing Cu% and flow rate/deposition time. Additionally, the refractive indices and dispersion parameters of the films are also affected by the deposition conditions. Cu doping enhanced the films' photostability as well as the photocatalytic removal of methylene blue (MB).     

基于FUJITSU公司MB86H20B平台的机顶盒软件结构设计与实现

机顶盒包括硬件系统和软件系统,数字电视节目的接收、呈现以及其他业务的实现、都需要软件系统来完成。本文主要介绍了机顶盒的软件系统模型,以及基于FUJITSU MB86H20B平台机顶盒的软件系统结构的总体设计。     

基于MB86296显卡芯片的显示平台设计

介绍了基于Linux操作系统使用MB86296显卡芯片构建高性能雷达显示平台的基本方法。首先介绍了MB86296显卡芯片的特性,给出了硬件平台的搭建过程和Linux系统帧缓冲的处理机制及底层显卡驱动程序的编写,解决了Powerpc固有的大端模式特性引起的PCI设备通信不正常的问题。最后通过实际测试,验证了工作的正确性,并将此高性能显示平台成功应用于某型号雷达显示设备中。     

MB-OFDM系统中采用梳状导频的信道估计

针对采用梳状导频的多频带正交频分复用(MB-OFDM)系统,提出一种新的基于频域插值定理的信道估计算法,即FD-INTERP.与传统的插值信道估计算法不同.FD-INTERP算法首先计算出导频点处的信道值,再根据DFT频域插值定理计算出时域信道.算法仅需较少的导频符号,提高了频带利用率,并且避免了插值计算,提高估计精度的同时降低了运算量.仿真结果表明该算法具有良好的可靠性和稳定性.     

Design of an Ultra‐Wideband Antenna Using a Ring Resonator with a Notch Function

This paper describes an ultra‐wideband (UWB) antenna that uses a ring resonator concept. The proposed antenna can operate in the entire UWB, and the IEEE 802.11a frequency band can be rejected by inserting a notch stub into the ring resonator. The experiment results indicate that the measured impedance bandwidth of the proposed antenna is 17.5 GHz (2.5 GHz to at least 20 GHz). The proposed UWB antenna has omnidirectional radiation patterns with a gain variation of 3 dBi (1 dBi to 4 dBi).     

Biosensors as a tool for the antioxidant status evaluation

Antioxidants are one of the main ingredients that protect food attributes by preventing oxidation that occurs during processing, distribution and end preparation of food. Physiological antioxidant protection involves a variety of chemical system of endogenous and exogenous origin in a multiplicity of pathways. Associate to this, researches have been directed in the development of methods as biosensors that can characterize antioxidants capable of removing harmful radicals in living organisms in an adequate way. Biosensors have represented a broad area of technology useful for environmental, food monitoring, clinical applications and can represent a good alternative method to evaluate the antioxidant status.The demonstration of the highlighted current application of biosensor as a potential tool to evaluate the antioxidant status is the main aim of this review.     

Electrochemical detection of short sequences related to the hepatitis B virus using MB on chitosan-modified CPE

A novel electrochemical DNA biosensor based on methylene blue (MB) and chitosan-modified carbon paste electrode (CCPE) for short DNA sequences and polymerase chain reaction (PCR) amplified real samples related to the hepatitis B virus (HBV) hybridization detection is presented. Differential pulse voltammetry (DPV) was used to investigate the surface coverage and hybridization event. The decrease in the peak current of MB, an electroactive label, was observed upon hybridization of probe with the target. Numerous factors affecting the target hybridization and indicator binding reaction are optimized to maximize the sensitivity.     

RE-B共掺杂片层TiO2的合成及其光催化性能

采用溶胶-凝胶法,利用钛酸四丁酯、硝酸镧、硝酸铈和硼酸为原料,对TiO₂光催化剂进行稀土-B(RE-B)的共掺杂改性制备和性能研究。采用X-射线衍射法(XRD)、冷场发射扫描电子显微镜(SEM)、X射线光电子能谱(XPS)、紫外-可见吸收(UV-Vis)光谱和荧光(PL)光谱对制得样品的相组成、表面形貌结构、表面元素组成、光响应范围及带隙能和电子-空穴的复合情况进行了初步分析。结果表明,所制掺杂TiO₂的组成均为锐钛矿型,掺杂使晶格发生了较大畸变,且细晶粒由未掺杂的27 nm减小到RE-B-TiO₂的10 nm,形貌为片层状不规则堆放状态存在。XPS结果表明掺杂元素有效进入二氧化钛, PL谱显示共掺杂可有效延长光催化剂的载流子寿命。掺杂后吸收边均红移, La-B-TiO₂由TiO₂的405 nm移动到466 nm,相应地禁带宽度减小了0.4 eV。光催化实验表明:2 h内降解亚甲基蓝(MB)时掺杂能够同时提高紫外和可见光下二氧化钛的光催化效率,而共掺杂的降解效果又优于单掺杂, La-B-TiO₂紫外光下的降解率达到80.67%,为同等条件下纯TiO₂的2.7倍,可见光下的降解率为74.78%。