Due to its diverse bonding hybridization forms (sp, sp2and sp3), amorphous carbon exhibits multifaceted properties and important application prospects, which have aroused extensive research interest[1–5]. In amorphou...
详细信息
Due to its diverse bonding hybridization forms (sp, sp2and sp3), amorphous carbon exhibits multifaceted properties and important application prospects, which have aroused extensive research interest[1–5]. In amorphous solids, some degree of atomic short-to medium-range order is thought to be ubiquitous, and the recent synthesis of new amorphous carbon has further increased our understanding of the atomic disorder in materials [4].
Hot deformation of sintered billets by powder metallurgy(PM)is an effective preparation technique for titanium alloys,which is more significant for high-alloying *** this study,Ti–6.5Al–2Zr–Mo–V(TA15)titanium allo...
详细信息
Hot deformation of sintered billets by powder metallurgy(PM)is an effective preparation technique for titanium alloys,which is more significant for high-alloying *** this study,Ti–6.5Al–2Zr–Mo–V(TA15)titanium alloy plates were prepared by cold press-ing sintering combined with high-temperature hot *** microstructure and mechanical properties under different process paramet-ers were *** microscope,electron backscatter diffraction,and others were applied to characterize the microstructure evolution and mechanical properties strengthening *** results showed that the chemical compositions were uniformly dif-fused without segregation during sintering,and the closing of the matrix craters was accelerated by increasing the sintering *** block was hot rolled at 1200℃ with an 80%reduction under only two passes without *** strength and elongation of the plate at 20–25℃ after solution and aging were 1247 MPa and 14.0%,respectively,which were increased by 24.5%and 40.0%,respect-ively,compared with the as-sintered alloy at 1300℃.The microstructure was significantly refined by continuous dynamic recrystalliza-tion,which was completed by the rotation and dislocation absorption of the substructure surrounded by low-angle grain *** hot rolling combined with heat treatment,the strength and plasticity of PM-TA15 were significantly improved,which resulted from the dense,uniform,and fine recrystallization structure and the synergistic effect of multiple slip systems.
The slow phase transformation of microalloyed dual phase steel makes the nonuniform stress and temperature fields during the post rolling cooling process have a significant impact on the phase transformation *** the r...
详细信息
The slow phase transformation of microalloyed dual phase steel makes the nonuniform stress and temperature fields during the post rolling cooling process have a significant impact on the phase transformation *** the relatively slow phase transformation of DP780 steel within the microalloyed dual phase steel series,the influence of stress on the phase transformation behavior of DP780 steel was *** quantify the nonuniform thermal and stress conditions in the steel coil,a thermo-mechanical coupled finite element model of the hot-rolled strip cooling process was *** on the simulation data,DP780 steel was chosen as the research material,and Gleeble 3500 thermal simulation equipment was used for experimental *** thermal expansion curves were analyzed through regression to establish the dynamic model of DP780 steel phase transformation under ***,metallographic analysis was conducted to determine phase transformation type and grain size of DP780 *** results confirmed that the stress promotes the occurrence of semi-diffusion-type bainite ***,an appropriate level of stress facilitates the growth of bainitic grains,while the increased stress inhibits the growth of ferritic grains.
Using THz emission spectroscopy,we investigate the elementary spin dynamics in ferromagnetic single-layer Fe on a sub-picosecond *** demonstrate that THz radiation changes its polarity with reversal of the magnetizati...
详细信息
Using THz emission spectroscopy,we investigate the elementary spin dynamics in ferromagnetic single-layer Fe on a sub-picosecond *** demonstrate that THz radiation changes its polarity with reversal of the magnetization applied by the external magnetic *** addition,it is found that the sign of THz polarity excited from different sides is defined by the thickness of the Fe layer and Fe/dielectric *** on the thickness and symmetry dependences of THz emission,we experimentally distinguish between the two major contributions:ultrafast demagnetization and the anomalous Hall *** experimental results not only enrich understanding of THz electromagnetic generation induced by femtosecond laser pulses but also provide a practical way to access laser-induced ultrafast spin dynamics in magnetic structures.
Organizational research has increased in the contemporary, digitalized and global society. Mainly researchers in Western countries conducted empirical, organizational research in the past. These studies have investiga...
详细信息
Rare earth-based superlattice alloys have great potential for gaseous hydrogen storage,as well as successful application as nickel-metal hydride batteries *** this work,Y substitution was carried out to adjust the gas...
详细信息
Rare earth-based superlattice alloys have great potential for gaseous hydrogen storage,as well as successful application as nickel-metal hydride batteries *** this work,Y substitution was carried out to adjust the gaseous hydrogen storage properties of A_(2)B_(7)-type La_(0.7)Mg_(0.3)Ni_(3.5)*** results indicate a multiphase structure in the alloys comprised of the main rhombohedral Gd_(2)Co_(7)and PuNi_(3)phases,with a small amount of CaCu_(5)***,the Y substitution results in higher abundance of the Gd_(2)Co_(7)*** alloy La_(0.42)Y_(0.28)Mg_(0.3)Ni_(3.5)exhibits a hydrogen storage cap acity of 1.55 wt%at 298 K and a desorption plateau pressure of 0.244 *** addition,this alloy demonstrates a stable cycle life by a capacity retention of 94.2%after 50 cycles,with the main capacity degradation occurring during the initial 20 *** work accentuates the potential of the La-Y-Mg-Ni-based superlattice alloys for applications in solid-state hydrogen storage.
We have fabricated a 180 °-twisted bilayer ReSe2 by stacking two centrosymmetric monolayer ReSe2 flakes in opposite directions, which is expected to cause the loss of spatial inversion symmetry. We successfully o...
详细信息
We have fabricated a 180 °-twisted bilayer ReSe2 by stacking two centrosymmetric monolayer ReSe2 flakes in opposite directions, which is expected to cause the loss of spatial inversion symmetry. We successfully observed spatial inversion-symmetry breaking, in contrast to the monolayer and natural bilayer ReSe2 by the second harmonic generation. ARPES measurements further revealed emergent band dispersions in the 180 °-twisted bilayer ReSe2, distinct from those of the monolayer ReSe2 used in its fabrication. The band calculation shows the finite lifting of spin degeneracy (∼50 meV) distinct from natural monolayer and bilayer ReSe2, which demonstrates that the spin-momentum locked state leading to Berry curvature related phenomena can be realized even with the stacking of centrosymmetric monolayers.
M23C6 chromium-rich carbides are common grain-boundary precipitations in Cr-containing *** presence of grain-boundary carbides often leads to intergranular brittleness and decreases mechanical *** study proposes a def...
详细信息
M23C6 chromium-rich carbides are common grain-boundary precipitations in Cr-containing *** presence of grain-boundary carbides often leads to intergranular brittleness and decreases mechanical *** study proposes a deformation and aging technique to obtain a high-volume-fraction dispersion distribution of the hard nano-M23C6 phase by changing the nucleation sites from grain boundaries to deformation coherent twin boundaries produced during cold *** M23C6 precipitation-strengthened austenitic stainless steel has a strength of up to 1.4 GPa but maintains favor-able plasticity(>11%).This study provides a novel approach for the control of intergranular brittleness in metallic materials.
Oxygen deficiency has crucial effects on the crystal structure and electrochemical performance of spinel oxide lithium electrode materials such as LiNi_(0.5)Mn_(1.5)O_(4)(LNMO)*** particular,the oxygen stoichiometry o...
详细信息
Oxygen deficiency has crucial effects on the crystal structure and electrochemical performance of spinel oxide lithium electrode materials such as LiNi_(0.5)Mn_(1.5)O_(4)(LNMO)*** particular,the oxygen stoichiometry on the crystal surface differs from that on the crystal interior in *** detection of local oxygen loss in LNMO and its correlation with the crystal structure and the cycling stability of LNMO remain *** this study,the effect of oxygen deficiency in LNMO controlled by sintering temperature on the surface crystal structure and electrochemical performance of LNMO is comprehensively *** high concentration of oxygen vacancies segregates at the surface regions of LNMO forming a thin rock‐salt and/or deficient spinel surface *** atomic‐level surface structure reconstruction was demonstrated by annular dark‐field and annular brightfield *** the synthesis of LNMO,the higher sintering temperature results in higher crystallinity but the higher oxygen deficiency in *** high crystallinity of LNMO would increase the thermal stability of LNMO cathodes while the high content of oxygen deficiency would decrease the surface structural stability of ***,the LNMO sintered at a medium temperature of 850°C achieved the best capacity *** results suggest a competitive function mechanism between oxygen stoichiometry and the crystallinity of LNMO on the cycling performance of LNMO.
Metal-phenolic networks(MPNs)are a versatile class of self-assembled systems that are generating interest for applications in catalysis,bioimaging,and drug *** contrast to traditional MPNs coating,in this research,we ...
详细信息
Metal-phenolic networks(MPNs)are a versatile class of self-assembled systems that are generating interest for applications in catalysis,bioimaging,and drug *** contrast to traditional MPNs coating,in this research,we fabricated novel MPNs microspheres through a facile process in the aqueous *** MPNs microspheres are characterized by SEM,TEM,and *** as-prepared microspheres were utilized in the removal of tetracycline(TC),methylene blue(MB),and rhodamine B(RhB).It exhibits high capacity(1331 mg/g)for the adsorption of MB,and a rapid reaction rate(186.9 mg/g/min)for the adsorption of TC.
暂无评论