[en] The magnetic properties of the mixed ferro-ferrimagnetic compounds with (A_aB_bC_c)_yD, in which A, B, C and D are four different magnetic ions and form four different sublattices, are studied by using the Ising model. And the Ising model was dealt with standard mean-field approximation. The regions of concentration in which two compensation points or one compensation point exit are given in c-a, b-c and a-b planes. The phase diagrams of the transition temperature T_c and compensation temperature T_comp are obtained. The temperature dependences of the magnetization are also investigated. Some of the result can be used to explain the experimental work of the molecule-based ferro-ferrimagnet (Ni^II_aMn^II_bFe^II_c)_1.5[Cr^III(CN)₆]·zH₂O

[en] Highlights: • The slope of P_m_a_x versus U_r_m_s is greater for nano-Al powder than for micro-Al powder. • The u_e_f_f_,_m_a_x of micro-Al and nano-Al powder-air mixtures increases linearly with U_r_m_s. • For micro- and nano-Al powders, u_e_f_f_, _m_a_x increases as the percentage of nano-Al increases. - Abstract: The environmental turbulence intensity has a significant influence on the explosion parameters of both micro- and nano-Al at the time of ignition. However, explosion research on turbulence intensity with respect to micro- and nano-Al powders is still insufficient. In this work, micro- and nano-aluminum powders were investigated via scanning electron microscopy (SEM), and their particle size distributions were measured using a laser diffraction analyzer under dispersing air pressures of 0.4, 0.6, and 0.8 MPa in a 20 L cylindrical, strong plexiglass vessel. The particle size distributions in three different mass ratio mixtures of micro- and nano-Al powders (micro-Al:nano-Al_[_m_a_s_s_r_a_t_i_o_] = 95:5, 90:10, and 85:15) were also measured. The results show that the agglomerate size of nano-Al powder is an order of magnitude larger than the nanoparticles’ actual size. Furthermore, the turbulence intensity ranges (U_r_m_s) of the Al powder-air mixtures were measured using particle image velocimetry (PIV) under dispersing air pressures of 0.4, 0.6, and 0.8 MPa. The effect of turbulence intensity on the explosion characteristics of the micro- and nano-Al powders was investigated using a 20 L cylindrical explosion vessel. The results of micro-Al and nano-Al powder-air mixtures with a stoichiometric concentration of 337.00 g·m"−"3 were discussed for the maximum explosion pressure, the maximum rate of pressure increase and the maximum effective burning velocity under the different turbulence intensity.

[en] Highlights: • The accuracy of characterizing the contrast of an isolated 25 attosecond pulse is highly dependent on the energy resolution of the electron energy spectrometer. • Magnetic-bottle electron energy spectrometer has insufficient resolution for accurate contrast measurement. • New design in the magnetic-bottle spectrometer improved the resolution by restricting the acceptance angle with a small pinhole. • The satellite pulse of the isolated 25 attosecond can be characterized with less than 10 percent error by the new magnetic-bottle spectrometer design. - Abstract: We quantify the effects of the energy resolution of a magnetic bottle electron spectrometer in an attosecond streak camera on the accuracy of measuring the relative amplitudes of satellite pulses around the main attosecond pulse. Our numerical simulations show that the spectral resolution can be significantly improved by restricting the acceptance angle using a pinhole located near the source of the photoelectrons. The intensity of the pre- and post-pulses which are 1% and 10% of a main 25 as pulse can potentially be measured with less than 10% error by two practical time-of-flight spectrometer designs

[en] This study was undertaken to investigate the influence of predeformation in rotary swaging strain induced melt activation (SIMA) process on the microstructural characteristics and mechanical properties of C5191 copper alloy. In this paper, plastic energy was utilized as an indicator to assess the value of stored energy in materials. The plastic energy of rotary swaging (RS) under different conditions was calculated by numerical simulation using FORGE 3D software and integral equations. The results showed that the plastic energy of RS was only related to the billet radial strain, and the plastic energy of each pass reduced with the increasing of the RS passes number. The twinning and dislocation distributions in the rotary swaged materials and semi-solid materials were analyzed by the electron backscatter diffraction technique. These results illustrated the migration of high-angle boundaries were migrated and defects were removed during recrystallization. Semi-solid C5191 alloy were prepared under different radial strains. It was found that the increase of plastic energy, decrease the spherical grains formation duration. Meanwhile, the high plastic energy promoted the refinement of spherical grains, the reduction of neck-grains number, and the enhancement of hardness. - Highlights: • Globular microstructures formation mechanism of RSSIMA process is recrystallization. • Effects of billet radial strain and die speed on plastic energy were studied quantitatively. • Larger plastic energy contributes to the grain sizes refinement and materials Vickers hardness improvement during IHT.

[en] Vertically stacked In_xGa_1-xAs/GaAs quantum dots have been fabricated by molecular beam epitaxy. Cross-sectional high resolution electron microscopy analyses demonstrate that the quantum dot size increases, and the interplanar spacings of {111} for quantum dots as well as the mismatch between the quantum dots and the spacer layers, is increased with the layer number. Chemical analysis shows that, as fabrication proceeds, indium content is increased and gallium content is decreased, leading to the changes of mismatch and interplanar spacing for the quantum dots. [copyright] 2001 American Institute of Physics

[en] In recent years more and more people have been paying attention to the development of electric vehicles. At the same time, due to the lack of innovation in business models, the promotion of electric vehicles has been relatively slow. The development model of electric vehicles is in urgent need of innovation. Considering the initial investment cost, operating costs, fuel cost and other expenses of electric vehicles, this paper designed a critical price model of alternative fuel vehicles in the whole life cycle from the consumers’ point of view. The results showed that users can use the electric vehicles when the selling price is lower than the critical price. And the rise of oil prices, the reduction of the initial investment of electric vehicles and the imposition of carbon tax will help to improve the critical price and promote the development of electric vehicles. Four kinds of promotion models for the electric vehicle from three angles of risk transfer, risk reduction and risk sharing have been designed. The point of difference between critical price and current electricity price will be the expected per kWh for the promotion of electric vehicles has been put. - Highlights: • The critical sale price model of electric vehicle is constructed based on LCC. • The mode of electric vehicle subsidies is extended. • Sensitivity analysis is carried out on the different influence factors of the critical price. • Four kinds of modes to promote the development of electric vehicles are designed. • The specific electric vehicle promotion and implementation suggestions are put forward.

[en] The possibility of γ-ray laser generation by the radiation of wiggling electrons in a usual background laser is discussed. (paper)

[en] Within the framework of the effective-field theory with correlations, the ferromagnetic spin-1 Ising model with biaxial crystal-field on honeycomb lattice is studied. The effects of the biaxial anisotropy parameters on the phase diagrams, tricritical points are investigated. The results show that the tricritical points and reentrant phenomena may appear in certain ranges of the two transverse crystal-field interactions

[en] Compensation points of layer system consisting of mixed spin-2 and spin-((5)/(2)) ferrimagnetic honeycomb lattice layers which are coupled together with two kinds of positive interlayer coupling are examined by the use of the effective-field theory with correlations (EFT). In particular, the effects of interlayer coupling and a positive crystal-field constant of the spin-2 ions on the compensation temperature are investigated, in order to clarify the characteristic behavior of the temperature dependence of the total magnetization M. This is related to the experimental works of a molecular-based magnetic multilayer film, N(n-C₄H₉)₄Fe^IIFe^III(C₂O₄)₃. A comparison is made between the results in this paper and those in a previous work obtained by using Monte-Carlo simulations

[en] The ICIS at Tianwan Nuclear Power Station is the only first in China to successfully realize reactor protection functions by linear power density and DNBR. As the kernel detectors of ICIS, NTMC plays an extremely important role. And the performance of the detector is very important to the system's reliability. Based on the experience of TNPS, this study gives an research and development of the service life and replacement strategy for the detector. (author)