Performance of a non‐load‐bearing steel stud gypsum board wall assembly: Experiments and modelling

A gypsum wall assembly was exposed to an intense real‐scale compartment fire. For the wall assembly, temperatures were measured at the exposed face, within the stud cavity, and at the unexposed face during the fire exposure. Total heat flux gauges were used to measure the temporal variation of the energy incident on the walls, and cameras, both visual and infrared, were used to image the unexposed face of the wall assembly during the fire exposure. The behaviour of the wall assembly under the fire load is discussed as are current model results for a simulation of the fire test. Copyright © 2006 John Wiley & Sons, Ltd.     

三维有限元法分析频率对接地电阻的影响

提出了用涡流场的A-V有限元分析方法计算接地系统接地电阻的方法,分析了入地电流频率的变化对接地电阻的影响。计算结果表明,频率对接地体自身电阻的影响较大,但对散流电阻的影响很小。     

Surface Hardening of High-Strength Low Alloy Steels (HSLA) Dual-Phase Steels by Ball Burnishing Using Factorial Design

Burnishing is used increasingly as a finishing operation which gives additional advantages such as increased hardness, fatigue strength, and wear resistance. Experimental work based on 3⁴ factorial design was carried out to establish the effects of ball burnishing parameters on the surface hardness of high-strength low alloy steels (HSLA) dual-phase (DP) steel specimens. Statistical analysis of the results shows that the speed, feed, lubricant and ball diameter have significant effect on surface hardness.     

Extracting Electron Densities in N-Type GaAs From Raman Spectra: Theory

In this paper, we present the theory for calculating Raman line shapes as functions of the Fermi energy and finite temperatures in zinc blende, n-type GaAs for donor densities between 10¹⁶ cm⁻³ and 10¹⁹ cm⁻³. Compared to other theories, this theory is unique in two respects: 1) the many-body effects are treated self-consistently and 2) the theory is valid at room temperature for arbitrary values of the ratio R = (Q²/α), where Q is the magnitude of the normalized wave vector and α is the normalized frequency used in the Raman measurements. These calculations solve the charge neutrality equation self-consistently for a two-band model of GaAs at 300 K that includes the effects of high carrier concentrations and dopant densities on the perturbed densities of states used to calculate the Fermi energy as a function of temperature. The results are then applied to obtain the carrier concentrations from Fermi energies in the context of line shapes in Raman spectra due to the coupling between longitudinal optical phonons and plasmons. Raman measurements have been proposed as a non-destructive method for wafer acceptance tests of carrier density in semiconductor epilayers. The interpretation of Raman spectra to determine the majority electron density in n-type semiconductors requires an interdisciplinary effort involving experiments, theory, and computer-based simulations and visualizations of the theoretical calculations.     

An investigation of the relation between the temperature dependences of the initial unbalance and the output signal of resistance strain sensor bridge circuits

The relation between the initial unbalance and the output signal of bridge circuits when acted upon simultaneously by the physical factor being measured and the temperature of the surroundings when the bridge is supplied from a voltage or current source is investigated. Analytic relations are obtained which explain the temperature dependence of the useful output voltage under external physical action. __________ Translated from Izmeritel’naya Tekhnika, No. 1, pp. 48–49, 2007.     

FY-14吸附剂用于大庆减三线润滑油基础油精制

采用有机酸改性活性白土FY—14吸附剂对大庆减三线润滑油基础油的脱氮效果进行详细考察，并与活性白土进行对比。研究结果表明，白土精制温度较高，在150℃时5．0％白土用量的碱性脱氯事为88．3％，而在100℃时2．5％FY-14吸附剂用量的碱性氮脱除率为95．6％，硫脱除率为13．2％，旋转氧弹值为268min。随着碱性氯脱除率提高，精制油折光率呈不断下降趋势。上述实验结果表明，采用FY—14吸附荆精制基础油可达到节能降耗、提高基础油收率和氧化安定性的效果。     

超微粉石墨层间化合物FeCl3-NiCl2-GICs的制备及电磁性能研究

以微粉石墨为主体材料合成出不同阶结构的FeCl3-NiCl2-GICs.应用XRD、SEM对产物的晶体结构与表面形貌进行分析表征.采用范德保法测量产物在常温常态下的电阻率,用MODEL9600振动磁强计测量GICs在0～7.958×105A/m磁场强度下的磁化强度、磁化率.测量数据表明异类原子FeCl3、NiCl2插入石黑层间后,GICs的电导率增加1.3～2.9倍,其磁性由石墨的抗磁性转变为顺磁性.     

Mid-Temperature Synthesis of CeO2-TiO2 Complex Compound and Its XRD Structure Study

TiO2 andCeO2 aresemiconductormaterials .TiO2hasthepropertiesofphoto catalysis[1] whileCeO2 hastheabilityofoxygenstorageandcanpromotethedispersionofprecionsmetalsonthesupporter[2 ] .CeO2 TiO2 com plexcompoundwasusedascatalystandspecialfunction almaterial[3～ 5] .ThetraditionalsynthesisofCeO2 TiO2complexcompoundisbyceramicmethodthatusesoxidesasrawmaterialsanditiscalcinedabove 130 0℃[6～ 8] .However ,thestructureandmicrostructureofthecomplexcompoundarenotsuitableforcatalystandfunctionalm…