[en] Highlights: • The effect of cooling method after intercritical heat treatment on microstructure evolution was investigated. • Fracture mechanism of tensile and impact after different intercritical heat treatment has been analyzed. • The crack initiation and propagation after different intercritical heat treatment was compared in details. - Abstract: The effect of cooling method after intercritical heat treatment on the microstructures and mechanical properties of as-cast steel produced by electroslag casting was investigated. The microstructure characteristics were analyzed by optical microscope (OM), scanning electron microscope (SEM), transmission electron microscopy (TEM) and electron back scatter diffraction (EBSD). The mechanical performance was evaluated by tensile testing at ambient temperature and Charp V-notch impact tests at various temperatures (−40 °C, −20 °C, 20 °C). The tensile and impact fracture micromechanisms were discussed in details. The results of microstructure investigation indicated that water cooling after intercritical heat treatment led to a mixed microstructure of ferrite and tempered martensite, while a composite microstructure of ferrite and tempered bainite was obtained after air cooling. The carbides of Cr, Mo and Nb in matrix after water quenching were finer than the ones after air cooling. Compared with water cooling, a good balance of strength and toughness was obtained after air cooling. The crack propagation path in the steel after water cooling can propagate along the long axis direction of ferrite bands, directly across the intersecting banded ferrite and martensite as well as along the interfaces between ferrite and martensite. However, the crack propagation path in the steel after air cooling depends on the shape, size and distribution of M/A islands

[en] With the development of clean coal technology, modern coal-fired power plants have achieved the similar emission standards as gas power plants. However, due to the impressions of high pollution and high emission in traditional coal-fired power plants, such projects are often opposed by local residents, which hinder the promotion of this technology. This manuscript aims to investigate public attitudes toward these projects and to analyze the influencing mechanisms of the factors of public support. The conceptual model was built with sense of place, trust and environmental attitude as the independent variables, benefit and cost perceptions as the mediating variables and public support as the dependent variable. The model was tested and modified by structural equation modelling. The results revealed that sense of place had a slight indirect impact (−0.043) on public support through benefit perception, whereas trust had a direct impact (0.332) on public support and indirect impacts (0.298) through benefit and cost perceptions. Environmental attitude had indirect impacts on public support through benefit perception (0.180) and cost perception (−0.115). In addition, policy suggestions on decision-making, project publicity and compensation strategy are proposed to enhance public support for similar projects. - Highlights: • This manuscript aims at eliminating the NIMBY effects on modern coal-fired power plant project. • A SEM model is proposed to explore how potential factors affect public support. • Trust is the dominant influencing factor to improve public support with both direct and indirect impacts. • Environmental attitude can also have positive effect on public support through rational compensation plans.

[en] The propagator for an anisotropic two-dimension charged harmonic oscillator in the presence of a constant external magnetic field and a time-dependent electric field is exactly evaluated. Various special cases appearing in the literature can be obtained by properly setting the values of the parameters in our results. (authors)

[en] 

Introduction

In the era of rituximab, the NCCNIPI is widely used in clinical practice as a tool for the prognosis and risk stratification of diffuse large B-cell lymphoma (DLBCL). In recent years, FDG PET/CT has also shown unique prognostic value. We try to further confirm the prognostic role of metabolic parameters in the overall and subgroups patients.

Methods

We retrospectively analysed 87 DLBCL patients who underwent baseline FDG PET/CT and followed the R-CHOP or R-CHOP-like strategy. The clinical parameters and PET-related metabolic parameters were evaluated.

Results

For all patients, the 2-year PFS rate was 65.5% and the 2-year OS rate was 66.7%. According to Cox multivariate analysis, a high NCCNIPI score (4-8 points) and an MTV greater than 64.1 cm³ (defined by ROC) were independent prognostic factors for PFS and OS. The patients were divided into low, low-intermediate, high-intermediate and high-risk groups by NCCNIPI score. The 2-year PFS rates in each group were 90.9%, 71.3%, 33.2% and 16.7%, and the 2-year OS rates were 100%, 81.6%, 48.4% and 16.7%. In the subsequent subgroup analysis by MTV, it could further stratified low-intermediate and high-intermediate NCCNIPI groups, the P value was 0.068 and 0.069 for PFS, 0.078 and 0.036 for OS.

Conclusions

MTV, as a tumor metabolic volume parameter, and the NCCNIPI score were independent predictors of prognosis in general DLBCL patients. In the low-intermediate and high-intermediate NCCNIPI subgroup, we further confirm the risk stratification abilities of MTV, which could add the prognostic value of NCCNIPI.

[en] Co₂Z barium ferrite composite with the added graphite powder was prepared to increase the permittivity. The calculated results showed that the stronger reflection loss (RL) peak and the smaller absorber thickness were simultaneously achieved compared with the pure Co₂Z barium ferrite composite with the same permeability but lower permittivity. The origin of the absorption peaks was discussed by quarter-wavelength cancellation. By measuring the reflection coefficient of the composites without (S_11-OPEN) and with (S_11-SHORT) a backed metal plate, the separated electromagnetic wave energy reflected at the air–absorber interface and the absorber–metal plate interface was achieved, and they were used to deeply investigate the reason of the RL enhancement. - Highlights: • The permittivity of the Co₂Z barium ferrite composite was enhanced by adding the graphite powder into the composite. • The higher permittivity leads to the enhanced electromagnetic wave energy reflected from air–absorber interface. • The enhanced electromagnetic wave energy reflected from air–absorber interface results in strong absorption peaks. • The origin of the RL enhancement was deeply investigated

[en] In order to make a more detailed study on the ²³²Th fission process, the cross section of ²³²Th(n,f)¹³¹Sb fission reaction induced by 14 MeV neutrons was measured precisely with the neutron activation method and off-line gamma ray spectrometric technique. Neutron flux was monitored on line using the accompanying α particle from T(d,n)⁴He reaction in the irradiation and neutron energies were given by the cross section ratio of ⁹⁰Zr(n,2 n)⁸⁹Zr reaction to ⁹³Nb(n,2 n)^{92 m}Nb reaction. The experimentally determined cross sections were deduced to be 6.27±0.47, 6.19±0.54, 6.00±0.51 mb at 14.1±0.3, 14.5±0.3 and 14.8±0.3 MeV, respectively. - Highlights: • The fission cross section of ²³²Th(n,f)¹³¹Sb was measured using the neutron activation method. • Neutron energies were measured by the cross sections ratio method. • Deduced cross sections were 6.27±0.47, 6.19±0.54, 6.00±0.51 mb at 14.1±0.3, 14.5±0.3 and 14.8±0.3 MeV, respectively.

[en] By using the path integral approach, we investigate the problem of Hooke's atom (two electrons interacting with Coulomb potential in an external harmonic-oscillator potential) in an arbitrary time-dependent electric field. For a certain infinite set of discrete oscillator frequencies, we obtain the analytical solutions. The ground state polarization of the atom is then calculated. The same result is also obtained through linear response theory. (general)

[en] We investigate the time evolution of the wave function for a many-particle system in an external harmonic potential and a spatially homogeneous time-dependent driving field. The time-dependent wave function is found to be a phase factor times the shifted initial state wave function. This then provides a new proof of the harmonic-potential theorem

[en] Background: During the past few decades, metal nanoclusters have received considerable research interests for their distinct optical, catalytic and electronic properties. However, till today, most studies are focused on the synthesis, structure and properties of Au and Ag clusters, while the studies on Cu nanoclusters are rather rare because of its inherent instability. Purpose: We aim to synthesize the Cu nanocluster that has the tunable photoluminescence. Methods: Through varying the initial legend molar ratio of 2-mercapto-5-n-propylpyrimidine and dodecanethiol, a series of Cu nanoclusters with different emission wavelength were prepared. The photoluminescence property and structure of these nanoclusters were studied by the photoluminescence spectrometry (PL), X-ray absorption fine structure (XAFS) and Matrix Assisted Laser Desorption Ionization Time of Flight Spectrometer (MALDI-TOF) mass spectrometry. Results: (1) PL spectra showed that with the increase of the proportion of dodecanethiol, the maximum emission wavelength of Cu nanoclusters shifted from 618 nm to 571 nm. (2) Mass spectra results indicated that the main products were changed from Cu₅MPP₃ (MPP: 2-mercapto-5-n-propylpyrimidine) in the presence of MPP alone to Cu₄[MPP][C₁₂SH] when the dodecanethiol was introduced, and remains unchanged with increasing the dodecanethiol. (3) XAFS results showed that with the increase of dodecanethiol, the Cu-S bond length was shortened from 0.228 nm to 0.224 nm. Conclusion: The reduction of the amount of Cu atomic number would lead to the shift of emission wavelength from 618 nm to 597 nm, and the shortening of Cu-S bond length pushed down the HOMO level which was formed by the Cu(I)-S. With the increase of the HOMO-LUMO band gap, the emission wavelength of the products shifted from 597 nm to 571 nm. (authors)

[en] A simplified theoretical model for the linear Rayleigh–Taylor instability of finite thickness elastic–plastic solid constantly accelerated by finite thickness viscous fluid is performed. With the irrotational assumption, it is possible to consider viscosity, surface tension, elasticity or plasticity effects simultaneously. The model considers thicknesses at rigid wall boundary conditions with the velocity potentials, and deals with solid elastic–plastic transition and fluid viscosity based on the velocity continuity and force equilibrium at contact interface. The complete analytical expressions of the amplitude motion equation, the growth rate, and the instability boundary are obtained for arbitrary Atwood number, viscosity, thicknesses of solid and fluid. The thicknesses effects of two materials on the growth rate and the instability boundary are discussed. (paper)