Air-source heat pump coupled with economized vapor injection scroll compressor and ejector:Design and experimental research

Ejector can utilize high pressure energy from liquid mechanism,it can be used in heat pump system coupled with economized vapor injection(EVI)scroll compressor.When running under low temperature conditions,the performance of the EVI system with ejector can be improved further.In this paper,the design method of the heat pump system with ejector is presented,and the process for designing the heat pump with ejector(EVIe)was summarized.One prototype heat pump was designed under the condition of the evaporation ...     

Influence of Zn ion implantation on structures and field emission properties of multi-walled carbon nanotube arrays

The structures and field emission properties of multi-walled carbon nanotube arrays implanted with Zn+ by MEVVA ion implanter have been investigated.The results revealed that Zn+implantation induced structural damage and that the top of carbon nanotubes with multi-layered graphite structure were transformed into carbon nanowires with amorphous structure.Meanwhile,C:Zn solid solution was synthesized after Zn+ implantation.The turn-on field and threshold field were 0.80 and 1.31 V/μm,respectively for original...     

Conditional probability Markov chain simulation based reliability analysis method for nonnormal variables

Based on fast Markov chain simulation for generating the samples distributed in failure region and saddlepoint approximation(SA) technique,an efficient reliability analysis method is presented to evaluate the small failure probability of non-linear limit state function(LSF) with non-normal variables.In the presented method,the failure probability of the non-linear LSF is transformed into a product of the failure probability of the introduced linear LSF and a feature ratio factor.The introduced linear LSF wh...     

Alekseevskii-Tate revisited:An extension to the modified hydrodynamic theory of long rod penetration

The modified hydrodynamic theory of long rod penetration into semi-infinite targets was established independently by Alek-seevskii and Tate over forty years ago and since then many investigators contributed much to the development of the high speed penetration mechanics.However,in all the models proposed so far,the target resistance Rt is not well defined and usually determined by adjusting it until the predicted depth of penetration comes to an agreement with experimental data.In this paper,assumptions are...     

Computation of concentrations of characteristic atoms of alloys in BCC structure

In this paper,taking Nb-Mo alloy system as an example,the equations of concentration of characteristic atoms of alloys in BCC structure were obtained on the basis of the idea of systematic science of alloys and the number of coordination atoms.The concentrations of characteristic atoms in B2-NbMo type ordered alloys were calculated as functions of ordering degree(s) and composition xMo.When s=smax,the concentrations of characteristic atoms of stoichiometric B2-NbMo intermetallic compound are equal to that o...     

Investigation on film cooling characteristics from a row of converging slot-holes on flat plate

Experimental and numerical researches were conducted to investigate the cooling performance of a single row of consoles (converging slot-hole) on a large-scale flat-plate model. The results show that the coolant flow from a row of consoles shows good lateral uniformity of adiabatic effectiveness, with regions of slightly enhanced cooling occurring between the consoles. For the console cooling geometry, the interaction between coolant jet from inclined console and the mainstream flow results in reasonable vo...     

Progress and recent trend in MILD combustion

Moderate or intense low oxygen dilution(MILD)combustion plays a significant role in the mitigation of combustion-generated pollutants and greenhouse gases whilst meeting thermal efficiency needs.However,due to the lack of the fundamental knowledge on this combustion,there is a misconception that MILD combustion should be established by high preheating of the air,which has limited its application.Our research and development on this combustion has been performed for several years. We have found that the requ...     

Study on early warning index of spatial deformation for high concrete dam

Owing to the deficiency in early warning for high concrete dam,a formula was established to characterize the deformation behavior of high concrete dam as a whole.The early warning index of spatial deformation was calculated by low probability principle on the basis of the deformation entropy formula proposed.The steps were as follows.Firstly,the probability method was utilized to define the degree of order and degree of chaos for each survey point.Secondly,the weight distribution among the survey points was...     

Cu-Zn-Al形状记忆合金直接淬火和分级淬火后马氏体稳定性的研究SCIEI

用透射电镜,X射线衍射仪和电阻法研究了Cu-14.84wt-％Zn-7.75wt-％Al形状记忆合金在直接淬火和分级淬火后马氏体的稳定性。试验结果表明,直接淬火和分级淬火(150℃,2min)后于室温时效约3h的马氏体均为M18R结构,但刚直接淬火后马氏体并不稳定,其某些衍射峰位置和电阻率均随室温时效而变化;而分级淬火(150℃,2min)后马氏体是稳定的,其所有衍射峰位置和电阻率几乎不随室温时效而变化。上述结果可用“马氏体再有序化机制”解释。     

IMPROVEMENT ON FATIGUE LIFE OF ALLOY LY12CZ AFTER LASER RADIATION AND ITS DAMAGE EVOLUTION

The change of microstructure of fatigue specimens before and after laser radiation was studiedby transmission electron microscopy.The results show that the diameter of dislocation cell λtends to a constant at fatigue failure.Based on the principles of continuous damagemechanics,expressions of the fatigue damage criterion and processes of fatigue damage evolu-tion for L Y12CZ have been derived.