Constraint graph used to minimize on-chip wiring area with regard to electromigration and conductor voltage drop

A method employing the constraint graph is proposed for minimizing on-chip wiring area with regard to electromigration and conductor voltage drop. The approach is shown to accelerate area minimization considerably. It allows more types of constraint to be placed.     

一种微功耗轨到轨输出AB类运算放大器设计

在分析研究AB类运算放大器的输入和输出级构成原理基础上,提出一种与信号处理模块的输出端匹配并具有一定负载能力的缓冲器的设计。缓冲器采用了AB类运放结构,其输入级采用折叠式共射共基结构,输出级分别采用PNP管和NMOS管作为上拉管和下拉管,结合电路结构的改进使之具有轨到轨(rail-to-rail)的输出特性和很低的静态电流。设计的电路具有开环增益大、静态功耗小、带宽较高等特点。此运放已在1.5μmBCD工艺下实现。测试结果表明,静态电流仅为8.5μA,闭环带宽达200kHz,开环增益为100dB。     

家用电器软件评估要求

依据IEC60335—1：2006 Ed．4．2＋IS1：2007和IEC60730—1：2003Ed．3．1附录H相关软件评估条款的要求,系统介绍了家用电器软件评估技术,包括软件评估的目的和依据,需要进行软件评估的家用电器,评估的方法、术语及所需要的资料;详细介绍了可编程电子电路安全相关的软硬件结构要求与软件检查方法。     

基于数据字典的转换工具的设计与实现

根据数据通信中原始收发数据的格式,结合树型结构数据字典和模块化设计思想,设计了基于数据字典的转换工具的整体系统框架,将转换工具划分为接口、译码库(.lib)、回调函数和数据字典4个功能模块。在此基础上,使用Qt可视化程序开发软件,完成了基于树型结构数据字典的转换工具C++程序开发。最后,给出了转换工具的UML类图,并详细介绍了程序的工作流程。     

CATV基站的雷电保护与接地

分析雷击对基站的危害和基站雷电的入侵方式,根据雷电防护原理、电气安全要求和基站接地技术,结合CATV基站进出线路的实际情况和信号抗干扰要求,对CATV基站的电气保护与接地方法提出建议,为CATV基站稳定工作提供保障。     

川气东送用X70钢半自动焊接缺陷的应对

以川气东送管道工程用X70钢为研究对象,分析其焊接施工中常见焊接缺陷的出现几率和产生原因,并有针对性的制定预防措施。在现场施工中进行认真落实,在很大程度上提高了管道的焊接一次合格率,效果显著。     

Studies on the oxidation reaction of l-cysteine in a confined matrix of layered double hydroxides

The amino acid l-cysteine (l-Cys) was intercalated into a MgAl layered double hydroxide (LDH), and its oxidation reaction by hexacyanoferrate (III) (Fe(CN)₆³⁻) in the confined region between sheets of LDH has been studied in detail. Based on the measurement results of XRD, Raman and FT-IR, it was found that the interlayer l-Cys was oxidized to cystine by Fe(CN)₆³⁻. Furthermore, the kinetics of this reaction was investigated in batch mode. The influences of initial Fe(CN)₆³⁻concentration, l-Cys-LDH quantity and reaction temperature on the interlayer oxidation reaction have been studied, respectively. The reaction follows a diffusion-controlled mechanism represented by Crank-Ginstling and Brounshtein kinetic model with the apparent activation energy of 29.93 kJ/mol. Therefore, this layered material may have prospective application as a novel “molecular reactor” for confined chemical reactions.     

Electrocatalytic reduction of hydrogen peroxide at nanostructured copper modified electrode

The electrocatalytic reduction of hydrogen peroxide (H₂O₂) has been studied at nanostructured copper (Cu_nano) modified glassy carbon (GC/Cu_nano) electrode in phosphate buffer (pH 7.2). The electrical properties of GC/Cu_nano modified electrodes were studied by electrochemical impedance spectroscopy (EIS). Surface and electrochemical characterization were carried out by using atomic force microscopy (AFM) and cyclic voltammetry. A well-defined H₂O₂ reduction signal, which is due to mediation of a surface active site redox transition exhibits at the GC/Cu_nano electrode. The Cu_nano is acting as a bridge without the aid of any other electron mediator, which enables the direct electron transfer between the modified electrode and the substrate. The results are compared with bulk copper macroelectrode and emphasized the efficiency of the Cu_nano modified electrode. Systematic investigations were made to optimize the experimental parameter, such as applied potential (E_app) for copper electrodeposition. The calibration curve obtained from chronoamperometric studies was found to be linear in the range 0.5 to 8.0 μM H₂O₂ with a detection limit of ca.10 nM (S/N = 3) at the GC/Cu_nano electrode. The modified electrode is stable for 1 week in phosphate buffer after repetitive measurements.     

构筑开放式大课堂的教学模式——以城市总体规划课程设计为例

针对城市总体规划课程设计培养的目标,传统的教学模式不能适应新形势下的培养要求,从保障体系、教学体系、监控体系三方面探讨了开放式大课堂的教学模式。     

Modification of glassy carbon electrodes by 4-chloromethylphenyl units and d-glucosaminic acid

The present work is dealing with the attachment of d-glucosaminic acid (D-GA) on glassy carbon electrode by two different methods. Firstly, the electrode was modified by chloromethylphenyl groups by reduction of 4-chloromethylphenyldiazonium cations followed by the nucleophilic substitution of the chlorine by the amine functionality of D-GA and secondly by the direct immobilization of the amine terminated molecule. The generality of the nucleophilic substitution reaction and the direct immobilization of an amine were also demonstrated with reactants bearing an electroactive ferrocene moiety; 4-nitrophenylferrocene (NFc) and 4-ferrocenylaniline (FcA). The surfaces modified with FcA and NFc were investigated by cyclic voltammetry, and the D-GA modified electrodes were characterized by X-ray photoelectron spectroscopy. A preliminary evaluation of the efficiency of these surface modifiers to prevent protein adsorption was realized by scanning electron microscopy.