Multi-dimensional modeling of the application of catalytic combustion to homogeneous charge compression ignition engine

The detailed surface reaction mechanism of methane on rhodium catalyst was analyzed.Comparisons betweennumerical simulation and experiments showed a basic agreement.The combustion process of homogeneouscharge compression ignition(HCCI)engine whose piston surface has been coated with catalyst(rhodium andplatinum)was numerically investigated.A multi-dimensional model with detailed chemical kinetics was built.The effects of catalytic combustion on the ignition timing,the temperature and CO concentration fields,and HC,CO and NO_x emissions of the HCCI engine were discussed.The results showed the ignition timing of the HCCIengine was advanced and the emissions of HC and CO were decreased by the catalysis.     

Tensile properties and fracture characteristics of spray cast alloy IC6 （Ni-7.8Al-14Mo-0.05B）

Tensile testing results of spray cast Ni3Al-based superalloy indicated that the yield strength and tensile strength increase with the increasing of temperature and reached maximum at around 760℃, then decrease with the increasing of temperature. After high temperature isostatic pressing (HIP), yield strength decreased and ductility and tensile strength increased. Stereographic projection showed that no matter at room temperature, medium temperature or high temperature, cracks extend along (111).     

Corrosion of two kinds of cast steels containing chromium in hot concentrated alkaline

A typical hot concentrated alkaline corrosion environment exists in alumina metallurgical industry, so that steel materials with outstanding alkaline corrosion resistance are strongly demanded for its processing equipment. In this paper, the corrosion resistance of two kinds of martensitic cast steels containing chromium in static 303g/L NaOH alkaline solution at 85℃ was studied through polarization and potential-time curves, corrosion weight loss and corrosion morphology analysis. Experimental results showed that protection effect by passive film of cast steel containing Cr was temporary. The low carbon steel without Cr content also exhibited chemical passivity in the same solution. The corrosion mode of the tested Cr-containing cast steel was composed of active dissolving corrosion and caustic embrittlement cracking. Dissolving corrosion was the primary mechanism for the induced weight loss, while severe caustic embrittlement cracking was secondary. With the increase of chromium content in the cast steel, the tendency of the caustic embrittlement cracking decreased, while the active dissolving corrosion increased.     

Microstructure refinement of Sn-Sb Peritectic alloy by power ultrasonic

Sn-Sb peritectic alloy was treated with 400 W, 600 W and 800 W ultrasonic, respectively, to study the effect of power ultrasonic on solidification microstructure. Results show that power ultrasonic can refine α phase and β phase of the alloy, as well as eliminate gravitational segregation. Moreover, 600 W ultrasonic demonstrated the best refining effect, not only homogenous and fine solidification microstructure can be obtained, the cubical β phase crystals can also be spheroidized.     

INFLUENCES OF TRACE ADDITIONS OF STRONTIUM AND PHOSPHORUS ON ELECTRICAL RESISTIVITY AND VISCOSITY OF LIQUID Al-Si ALLOYS

ＩＮＦＬＵＥＮＣＥＳＯＦＴＲＡＣＥＡＤＤＩＴＩＯＮＳＯＦＳＴＲＯＮＴＩＵＭＡＮＤＰＨＯＳＰＨＯＲＵＳＯＮＥＬＥＣＴＲＩＣＡＬＲＥＳＩＳＴＩＶＩＴＹＡＮＤＶＩＳＣＯＳＩＴＹＯＦＬＩＱＵＩＤＡｌＳｉＡＬＬＯＹＳ①ＧｕｉＭａｎｃｈａｎｇ，ＪｉａＪｕｎ，...     

原子吸收分光光度法测定土壤中的镍的方法研究

本文对微波消解-原子吸收分光光度法测定土壤样品中的镍元素的分析方法进行了探讨,并对不同类型土壤消解后赶酸与不赶酸的测定结果进行了比较。结果表明,原子吸收法测定土壤中的镍必须赶酸,但赶酸的方法可以简化,并利用连续光源原子吸收光谱图进行了验证。     

Reaction of (C_5H_5)_2NdCl·2LiCl with n-Butyllithium: Formation and Crystal Structure of [Li(DME)_3][(C_5H_5)_3Nd(μ-H)Nd(C_5H_5)_3]

Reaction of (C_5H_5)_2NdCl·2LiCl with n-Butyllithium: Formation and Crystal Structure of [Li(DME)_3][(C_5H_5)_3Nd(μ-H)Nd(C_5H_5)_3]