High pressure die casting(HPDC)AlSi10Mn Mg alloy castings are widely used in the automobile *** can optimize the mechanical properties of castings through heat treatment,while the release of thermal stress arouses the...
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High pressure die casting(HPDC)AlSi10Mn Mg alloy castings are widely used in the automobile *** can optimize the mechanical properties of castings through heat treatment,while the release of thermal stress arouses the deformation of large integrated ***,the development of non-heat treatment Al alloys is becoming the hot *** addition,HPDC contains externally solidified crystals(ESCs),which are detrimental to the mechanical properties of *** achieve high strength and toughness of non-heat treatment die-casting Al-Si alloy,we used AlSi9Mn alloy as matrix with the introduction of Zr,Ti,Nb,and *** influences on ESCs and mechanical properties were systematically investigated through three-dimensional reconstruction and thermodynamic *** results reveal that the addition of Ti increased ESCs'size and porosity,while the introduction of Nb refined ESCs and decreased ***,large-sized Al_3(Zr,Ti)phases formed and degraded the mechanical *** introduction of Ce resulted in the poisoning effect and reduced mechanical properties.
To clarify the relationship between externally solidified crystals(ESCs)and other defects,e.g.,defect bands and pores,two dimensional(2D)and three dimensional(3D)characterization methods were adopted to analyze castin...
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To clarify the relationship between externally solidified crystals(ESCs)and other defects,e.g.,defect bands and pores,two dimensional(2D)and three dimensional(3D)characterization methods were adopted to analyze castings produced using a modified ingate system equipped with and without an ESC *** reduction of ESCs strongly reduced defect band width and shrinkage pore *** reducing the quantity and size of ESCs,net-shrinkage pores were transformed into isolated island-shrinkage *** determined via statistical analysis that the mechanical properties of high pressure die castings were strongly related to the size and fraction of the ESCs rather than porosity *** reduction of ESCs also caused tensile transgranular fracture modes to transform into intergranular fracture ***,casting pressurization strongly reduced pore morphology,volume,and size.
The principal distinction in transitioning from far-field multiple-input multiple-output (MIMO) systems to near-field MIMO configurations lies in the notable augmentation of spatial degrees of freedom (DoF). This incr...
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A strategy was proposed to predict accurately the dielectric permittivity and dielectric strength based on the Onsager local field *** molecular dynamic simulation was utilised to analyse the dipole moment fluctuation...
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A strategy was proposed to predict accurately the dielectric permittivity and dielectric strength based on the Onsager local field *** molecular dynamic simulation was utilised to analyse the dipole moment fluctuation in polyimide(PI)to reflect the polar-isation response of applied electric *** simulation results revealed that the optical dielectric permittivity and static dielectric permittivity were 2.62 and 3.34,showing that the electronic displacement polarisation of the PI acted as a major *** deviation between simulated and measured values of the frequency-dependent relative dielectric permittivity was no more than 5%,which exhibited high *** the polarisation response of the polar groups in the PI was at infrared frequencies,the conductive loss may be the dominant role in 102–106 Hz at room ***,the effect of Joule heat on the structure,dielectric permittivity and Young modulus was considered to accurately predict the dielectric strength of the PI(359 kV/mm),which was in agreement with experimental values in the *** results establish a clear correlation between structural characteristics and dielectric properties of the PI,which would be the theoretical insights into the design and synthesis of the PI with tailored dielectric properties.
Poor heat/flame-resistance of polyolefin(e.g.,polyethylene and polypropylene)separators and high flammability of organic electrolytes used in today’s lithium-ion batteries(LIBs)may trigger rare yet potentially catast...
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Poor heat/flame-resistance of polyolefin(e.g.,polyethylene and polypropylene)separators and high flammability of organic electrolytes used in today’s lithium-ion batteries(LIBs)may trigger rare yet potentially catastrophic safety ***,we mitigate this challenge by developing a heat-resistant and flame-retardant porous composite membrane composed of polyetherimide(PEI)and Al_(2)O_(3) nanowires(NWs).The membranes are fabricated based on an industrially scalable non-solvent-induced phase separation process,which results in an intimately interconnected porous network of Al_(2)O_(3) NWs and *** produced composite membranes exhibit excellent flexibility,thermal stability,and ***,the composite membranes exhibit minimal thermal shrinkage and superior tensile strength(16 MPa)at temperatures as high as 200℃,significantly exceeding the performance of conventional polyolefin *** with commercial separators,their superior wettability and higher ionic conductivity(by up to 2.4 times)when filled with the same electrolyte,larger electrolyte uptake(-190 wt.%),as well as improved cycle and rate performance demonstrated in LiNiMnCoO_(2)(NCM)-based LIBs make them attractive choices for a variety of electrochemical energy storage devices.
A radiation–temperature coupling model of optical fiber attenuation spectrum has been *** spectrum in Ge/P co-doped fiber ranging from 800 nm–1600 nm at different temperatures and doses was measured and decomposed a...
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A radiation–temperature coupling model of optical fiber attenuation spectrum has been *** spectrum in Ge/P co-doped fiber ranging from 800 nm–1600 nm at different temperatures and doses was measured and decomposed according to the configurational coordinate model based on which the power-law model was employed to predict the intensity of the color center absorption band at different *** the fiber loss in space was predicted by the *** work will benefit the application of fibers in a complicated radiation environment.
This paper investigates an event-triggered LADR-C (ETLADRC) for permanent magnetic synchronous motor (PMSM). Firstly, the ETLADRC is devised according to the canonical form of the model of PMSM, then the detailed algo...
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Oxidative desulfurization(ODS)is a promising technology to produce clean fuel with requiring superior catalysts to lower kinetic *** most ODS catalysts are based on crystalline transition-metal oxides(TMOs),extraordin...
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Oxidative desulfurization(ODS)is a promising technology to produce clean fuel with requiring superior catalysts to lower kinetic *** most ODS catalysts are based on crystalline transition-metal oxides(TMOs),extraordinary activity also can be achieved with amorphous ***,the origin of the remarkable catalytic activity of the amorphous TMOs remains greatly ***,we found the crucial role of Mo–O covalency in ruling the intrinsic catalytic activity of amorphous molybdenum oxides(MoO_(x)).Experimental and theoretical analysis indicated that the nonequivalent connectivity in the amorphous structure strongly enhanced Mo–O covalency,thereby increasing the content of electrophilic oxygen and nucleophilic molybdenum to favor the MoO_(x)–H_(2)O_(2) *** the boosted Mo–O covalency to improve the flexibility of the charge state,the amorphous MoO_(x)-based composite catalyst(PE-MoO_(x)/S-0.05)exhibited outstanding catalytic activity for ODS of fuel *** turnover frequency(TOF)value of the catalyst(18.63 h^(-1))was almost an order of magnitude higher than that of most reported crystalline MoO_(x)/molecular sieve composite *** in-depth understanding of the origin of the amorphous TMOs activity for ODS provides a valuable reference for developing ODS catalysts.
Aiming at the complex mechanism of coal slime water thickening process in coal preparation plant, which has the characteristics of multivariable and strong nonlinearity leading to the difficulty of realizing the intel...
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This paper presents an impedance control approach for human-robot interaction (HRI) systems without using torque sensors. A sliding-mode disturbance observer based on super-twisting algorithm is proposed to estimate t...
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