天然气分布式能源系统对燃气供应企业的影响

分析了天然气分布式能源系统的特点及发展现状。以西安铁路北客站分布式能源站项目为例,分析了该系统对燃气供应企业的影响。     

基于PLC810PG控制IC的LED路灯驱动电路

PLC810PG是一种带集成半桥驱动器的PFC与LLC组合离线控制器。基于PLC810PG的150W LED路灯电源,功率因数PF≥0.97,系统效率ηtotal≥92%,符合IEC61000-3-2中对谐波电流的规定限制。     

High-temperature preparation and electrochemical properties of TiO2 anatase phase-mounted carbon aerogels

TiO₂ anatase phase-mounted carbon aerogels (CAs) were synthesized via the sol–gel polymerization of a mixture of resorcinol, formaldehyde, and tetrabutyl orthotitanate, followed by gelation, supercritical drying, and carbonization in N₂ atmosphere. Ethanol was selected as the solvent in the sol–gel polymerization process. The morphology and microstructural characteristics of the TiO₂-mounted carbon aerogel sample were obtained using thermogravimetry, transmission electron microscopy, scanning electron microscopy, N₂ adsorption–desorption, and X-ray diffraction methods. The total pore volume and average pore sizes increased with TiO₂ addition. Titania phase in anatase form was found to be more homogeneously distributed in the CAs at 900 °C. The anatase–rutile transformation did not take place at carbonization temperatures from 500 to 1100 °C and cyclic voltammetry measurements showed that the TiO₂-mounted CAs exhibit good reversibility and high specific capacity as electrode materials, and the anatase in the carbon structure were not involved in the redox reactions. Electrochemical impedance spectroscopy demonstrated that the CA electrode behaves as an excellent capacitor with low resistance.     

使用法兰测量仪进行海底管线膨胀弯测量技术研究与应用

针对以往海底管线膨胀弯测量方法存在的问题,探索总结出利用法兰测量仪进行海底管线膨胀弯测量技术关键与实施要点。涠洲12-1项目实践表明,应用本文所介绍的膨胀弯测量技术,可以有效提高海管膨胀弯连接的合格率和工作效率,并大大降低作业成本。     

Modeling and analysis of power distribution networks for Gigabit applications

As the operating frequency of digital systems increases and voltage swing decreases, it becomes very important to characterize and analyze power distribution networks (PDNs) accurately. This paper presents the modeling, simulation, and characterization of the PDN in a high-speed printed circuit board (PCB) designed for chip-to-chip communication at a data rate of 3.2 Gbps. The test board consists of transmitter and receiver chips wirebonded onto plastic ball grid array (PGBA) packages on a PCB. In this paper, a hybrid method has been applied for analysis, which consists of the transmission matrix method (TMM) in the frequency domain and macromodeling method in the time domain. As an initial step, power/ground planes have been modeled using TMM. Then, the macromodel of the power/ground planes has been generated at the desired ports using macromodeling. Finally, the macromodel of the planes, transmission lines, and nonlinear drivers have been simulated in standard SPICE-based circuit simulators for computing power supply noise. In addition to noise computation, the self and transfer impedances of power/ground planes have been computed and the effect of decoupling capacitors on power supply noise has been analyzed. The methods discussed have been validated using hardware measurements.     

输电线路绝缘子串检测机器人设计与应用

设计一种绝缘子串带电检测机器人。该机器人可以沿着绝缘子串自由攀爬,集绝缘检测、外观检测于一体,可以有效判别绝缘子低、零值和表面裂纹等缺陷。详细介绍绝缘子串检测机器人的整体结构、工作原理及现场应用,该机器人的应用能够减轻人工检测的劳动强度,降低输电线路运行维护成本。     

A Novel Privacy Protection Scheme for Iris Identification

Wireless Personal Communications - With the development of iris technology, iris identification has been widely used in various domains, as an efficient security authentication pattern. However, as...     

Initial precipitation and coarsening of the γ phase in inverse Ni–Al alloys

Coalescence coarsening and Ostwald ripening as well as the kinetics of γ precipitation in the γ′ matrix of inverse Ni–Al alloys are investigated by phase field simulations. The ordering of the γ′ matrix during the initial phase transformation of inverse Ni–Al alloys is faster than clustering, and disordering of the γ precipitates is faster than dissolution. As the Al content increases from 20.2 to 20.8 at.% Al, the initial precipitation and growth of γ precipitates decelerates, and the volume fractions of γ precipitates decreases with higher Al content. The rate constants of steady-state coarsening decrease with decreasing volume fraction of γ precipitates, the particle size distributions (PSDs) are broader than the PSDs predicted by Lifshitz–Slyozov–Wagner theory at steady-state coarsening, and the PSD becomes broad with increasing volume fraction of γ precipitates. The simulated morphology and kinetics variation of the γ precipitates are similar to previous experimental results.     

基于MIKE11的白莲泾区域水量水质模型研究

为保障世博园区水安全、研究河网水力要素的时空变化过程及感潮河网水动力变化特性,应用MIKE11水环境模型软件,构建并改善了白莲泾区域水量(水文、水动力学)水质模型,并对模型进行重新率定、验证,所得计算值与实测值吻合较好.应用模型模拟了“6.29大雨”白莲泾区域的河道水量水质,提供了最优的泵闸联动调水方案.可为制定、优化调水方案和建立水资源环境管理决策支持系统提供科学依据.     

华北油田深井钻井新技术应用方案研究

近年来华北油田深井的数量不断增多,仅2008年超过4000 m的深井就有20多口.深部地层可钻性变差,造成机械钻速慢,钻井周期长.仅占全井35.4%的深井层段,钻井周期就占总周期的57.9%.为了提高机械钻速,缩短钻井周期,节约钻井成本,进行了适合华北油田的深井钻井新技术研究,形成了华北油田应用新技术的初步方案,为华北油田的提速工作打下了基础.