传承电气技术 倡导技术创新

电气时代杂志社为国内领先的电气技术刊群，旗下有《电工技术学报》、《电气时代》、《电工技术杂志》、《电气制造》四大业内权威媒体。

不破不立

“不破不立”，语出自“不破不立，不塞不流，不止不行”，原意是说不破除旧的，就不能建立新的。破，指突破、破除旧思想、旧文化、旧风俗、旧习惯等；立，指建设、建立新思想、新文化、新风俗、新习惯等。

Saudi Arabia＇s Growing Demand for Electricity： Some Strategic Recommendations

Demand for electricity in Saudi Arabia is growing at a significant annual rate of nearly 8%. It is expected that, by 2030, the demand will increase to about 120 GW per year, approximately three times the 2010 load. Satisfying this demand will require a significant investment in the power grid at an estimated cost, over the next 10 years, ofSAR （Saudi Arabia Riyal） 500 billion. Existing power plants rely on oil and natural gas, it is anticipated that meeting the demand in 2030 will consume 3 million barrels ofoil each day, which significantly impacting the economy by reducing the country＇s income from oil exports, which is a hot button for Saudi decision makers. This paper reviews the responses of various countries in meeting their loads, and therefore, draws recommendations for some resources that should, and should not, be considered best-candidate options for Saudi Arabia economically, technically and environmentally. The discussion primarily examines renewable and nuclear resources.

Electropolishing of titanium alloy under hydrodynamic mode

Titanium(Ti) alloys are widely used in aerospace industry due to the low density and high corrosion resistance. However, machining and polishing remain great challenges because of the hardness and chemical stability. With a home-made electrochemical machining workstation, cyclic voltammetry is performed at a wide potential range of [0 V, 20 V] to record the details of passivation and depassivation processes under a hydrodynamic mode. The results show that the thickness of viscous layer formed on the alloy surface plays a crucial effect on the electropolishing quality. The technical parameters, including the mechanical motion rate, polishing time and electrode gap, are optimized to achieve a surface roughness less than 1.9 nm, which shows a prospective application in the electrochemical machining of Ti and it alloys.

Liquid phase 3D printing for quickly manufacturing conductive metal objects with low melting point alloy ink

Conventional 3D metal printings are generally time-consuming as well as lacking of high performance printable inks.From an alternative way,here we proposed the method of liquid phase 3D printing for quickly making conductive metal objects.Through introducing metal alloys whose melting point is slightly above room temperature as printing inks,several representative structures spanning from one,two and three dimension to more complex patterns were demonstrated to be quickly fabricated.Compared with the air-cooling in a conventional 3D printing,the liquid-phase-manufacturing offers a much higher cooling rate and thus significantly improves the speed in fabricating the target metal objects.This unique strategy also efficiently prevents the liquid metal inks from air oxidation,which is hard to avoid otherwise in an ordinary 3D printing.The key physical factors(such as properties of the cooling fluid,air pressure within the syringe barrel and needle diameter,types and properties of the printing ink)and several interesting intermediate fluids interaction phenomena between liquid metal and conventional cooling fluids such as water or ethanol,which evidently affecting the printing quality,were disclosed.In addition,a basic route to make future liquid phase 3D printer incorporated with both syringe pump and needle arrays was also suggested.The liquid phase 3D printing,which owns potential values not available in a conventional method,opens an efficient way for quickly making conductive metal objects in the coming time.

The coupling effect of slow-rate mechanical motion on the confined etching process in electrochemical mechanical micromachining

By introducing the mechanical motion into the confined etchant layer technique(CELT), we have developed a promising ultraprecision machining method, termed as electrochemical mechanical micromachining(ECMM), for producing both regular and irregular three dimensional(3 D) microstructures. It was found that there was a dramatic coupling effect between the confined etching process and the slow-rate mechanical motion because of the concentration distribution of electrogenerated etchant caused by the latter. In this article, the coupling effect was investigated systemically by comparing the etchant diffusion, etching depths and profiles in the non-confined and confined machining modes. A two-dimensional(2 D) numerical simulation model was proposed to analyze the diffusion variations during the ECMM process, which is well verified by the machining experiments. The results showed that, in the confined machining mode, both the machining resolution and the perpendicularity tolerance of side faces were improved effectively. Furthermore, the theoretical modeling and numerical simulations were proved valuable to optimize the technical parameters of the ECMM process.

High yield fabrication of semiconducting thin-film field-effect transistors based on chemically functionalized single-walled carbon nanotubes

Here we report a simple and scalable method to fabricate high performance thin-film field-effect transistors(FETs) with high yield based on chemically functionalized single-walled carbon nanotubes(SWNTs) by organic radical initiators.The UV-Vis-NIR spectra,Raman spectra and electrical characterization demonstrated that metallic species in CoMoCat 65 and HiPco SWNTs could be effectively eliminated after reaction with some organic radical initiators.The effects of the substrate properties on the electrical properties of FET devices were investigated,and the results showed that the electrical properties of FET devices fabricated on high hydrophobic substrates were better than those on low hydrophobic substrates.Furthermore,it was found that FET devices based on 1,1'-azobis(cyanocyclohexane)(ACN)-modified CoMoCat 65 SWNTs exhibited more excellent electrical performance with effective mobility of ～11.8 cm2/Vs and on/off ratio of ～2×105 as compared with benzoyl peroxide(BPO)-modified CoMoCat 65 SWNTs and lauoryl peroxideand(LPO)-modified HiPco SWNTs,likely due to the introduction of the electron-withdrawing groups(CN group) on the SWNT surface.This method does not require nontrivial reaction conditions or complicated purification after reaction,therefore promising low-cost production of high-performance devices for macroelectronics.

Key Points of Designing Alarm System in Medical Electrical Equipment

This paper presents suggestions in aspects(which should meet the standards) such as alarm indication, system setup and system security during the designing process of alarm system in medical electrical equipment, which can be used as a reference for manufacturers.