[en] The surface morphology evolution of three thin polystyrene (PS)/polymethyl methacrylate (PMMA) blend films (<70 nm) on SiO_x substrates upon annealing were investigated by atomic force microscopy (AFM) and some interesting phenomena were observed. All the spin-coated PS/PMMA blend films were not in thermodynamic equilibrium. For the 67.1 and the 27.2 nm PS/PMMA blend films, owing to the low mobility of the PMMA-rich phase layer at substrate surfaces and interfacial stabilization caused by long-range van der Waals forces of the substrates, the long-lived metastable surface morphologies (the foam-like and the bicontinuous morphologies) were first observed. For the two-dimensional ultrathin PS/PMMA blend film (16.3 nm), the discrete domains of the PS-rich phases upon the PMMA-rich phase layer formed and the secondary phase separation occurred after a longer annealing time

[en] The characteristic γ-ray spectrum of TNT under soil induced by DT neutron is measured based on the PFTNA demining system. GEANT4 Monte Carlo simulation toolkit is used to simulate the whole experimental procedure. The simulative spectrum is compared with the experimental spectrum. The result shows that they are mainly consistent. It is for the first time to analyze the spectrum by Monte Carlo simulation, the share of the background sources such as neutron, gamma are obtained, the contribution that the experimental apparatus such as shielding, detector sleeve, moderator make to the background is analysed. The study found that the effective gamma signal (from soil and TNT) is only 29% of the full-spectrum signal, and the background signal is more than 68% of the full-spectrum signal, which is mainly produced in the shielding and the detector sleeve. The simulation result shows that by gradually improving the shielding and the cadmium of the detector sleeve, the share of the effective gamma signal can increase to 36% and the background signal can fell 7% eventually. (authors)

[en] SnO${}_2$-CdO (SCO) films and SnO${}_2$-CdO-In${}_2$O${}_3$ (SCIO) films are successfully deposited on Si (100) and glass substrates by radio frequency and direct current magnetron co-sputtering. The films are characterized by X-ray diffraction, scanning electron microscope, energy-dispersive X-ray spectroscopy, ultraviolet visible near-infrared spectroscopy, and four-point probes. SCO films exhibit Cd${}_2$SnO${}_4$ (011) preferred orientation, and the SCO film deposited at the sputtering power of 80W exhibits excellent crystalline quality and transmittance. The arrangement of clusters changes from sparse to dense when the indium element concentration increases. The resistivities of SCIO films are of two orders of magnitude lower than those of the SCO films. However, the visible light transmittances decrease slightly and the optical bandgap values decrease from 5.00 to 4.85 eV. The results indicate that the indium element plays an important role in improving the electrical properties of SCO films. SCIO films are expected to be a good candidate for transparent conductive films. (© 2023 Wiley‐VCH GmbH)

[en] Objective: To study the clinical value of adenosine triphosphate stress myocardial perfusion tomography imaging (ATP-MPI) in detection of coronary artery disease (CAD). Methods: There were 278 patients underwent ATP-MPI, 51 patients of them also underwent coronary angiography (CAG). Seventy-three patients underwent stress-rest myocardial perfusion tomography imaging with multi-stage submaximal exercise test (ST-MPI) and CAG serving as control group. Results: 1) Side effects: there were 11 different symptoms and atrioventricular conduction block (10 patients), sinoatrial conduction block (2 patients) occurred during ATP stress. Allopathy or interruption of ATP stress did not happen. 2) The sensitivity and specificity of ATP-MPI in detection of CAD were 97.1% and 82.4%, respectively, and those in detection of ≥50% narrowing coronary artery were 91.0% and 94.7%, respectively. 3) In patients without myocardial infarction, the sensitivity and specificity of ATP-MPI in detection of myocardial ischemia were comparable to those of ST-MPI. Conclusion: ATP-MPI is an accurate, safe modality and is comparable to ST-MPI in the detection of CAD

[en] Optical and electrical properties of single-crystal Si supersaturated with Se by ion implantation and followed by different thermal annealing conditions are reported. Si is implanted with 1 × 10¹⁶ cm^-2 Se ions at 100 keV. The total substitutional fraction of Se atoms in Si is 45% under the annealing at 800 ℃ for 30 min and the peak concentration of substitutional Se atoms is exceeded 1 × 10²⁰ cm^-3. A temperature-independent carrier concentration of 3 × 10¹⁹ cm^-3 is measured and the near-infrared absorption is closed to 30%. These results indicate the insulator-to-metal transition of the doped layer and the formation of impurity bands in the Si band gap. (authors)

[en] To find the biological effect of space mutagenesis on P. chlamydosporia. Totally 29 strains isolated from the colonies of survival space-induced strains were tested not only for their biological characteristics, such as morphology, colony growing rate, dry weight of mycelium, spore production, and the parasitism to the eggs of Meloidogyne incognita, but also for salt tolerance and benomyl resistance. The results showed that the biological characteristics of space-induced strains of P.chlamydosporia were significantly different from the original strain. For space-induced strains, the colony growing rate and dry weight of mycelium showed higher negative mutation rates, the spore production showed greater positive mutation rates, and the pathogenicity against the eggs of M. incognita was more great, for instance, the improved parasitic rates of Pc-m-4, Pc-m-6, Pc-m-10, Pc-m-15 and Pc-m-123 were 92.33%, 93.67%, 91.67%, 90.67% and 90.33%, respectively, higher than the parasitic rate of original strain (81.00%), besides, Pc-m-6 had a good resistance to the benomyl and Pc-m-10 was able to survive in the high salinity condition. The influence of space mutagenesis on P. chlamydosporia was significant, and the superior strains obtained showed potential in biological control of M. incognita. (authors)

[en] Using the tight-binding approximation and the transfer matrix method, this paper studies the electronic transport properties through a periodic array of quantum-dot (QD) rings threaded by a magnetic flux. It demonstrates that the even-odd parity of the QD number in a single ring and the number of the QD rings in the array play a crucial role in the electron transmission. For a single QD ring, the resonance and antiresonance transmission depend not only on the applied magnetic flux but also on the difference between the number of QDs on the two arms of the ring. For an array of QD rings, the transmission properties are related not only to the even–odd parity of the number N₀ of QDs in the single ring but also to the even–odd parity of the ring number N in the array. When the incident electron energy is aligned with the site energy, for the array of N rings with N₀ = odd the antiresonance transmission cannot occur but the resonance transmission may occur and the transmission spectrum has N resonance peaks (N − 1 resonance peaks) in a period for N = odd (for N = even). For the array of N rings with N₀ = even the transmission properties depend on the flux threading the ring and the QD number on one arm of the ring. These results may be helpful in designing QD devices. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

[en] [Background] The ¹⁵¹Eu neutron capture cross-section plays an important role in reactor physics and in the slow neutron capture of nuclear astrophysics. [Purpose] This study aims to distinguish two isomers of ¹⁵²Eu and measure neutron capture cross-section of ¹⁵¹Eu. [Methods] The ¹⁵¹Eu (n, γ) ¹⁵²Eu reaction cross-sections at the neutron energies from 0.01 MeV to 20 MeV were calculated by using software TALYS-1.8 which is a mature computer code for simulating nuclear reactions in present work. The accuracy of simulation calculation program was verified and compared the theoretical data with the existing experimental data from EXFOR cross-section database and the latest neutron activation cross-section data. [Results and Conclusions] The results show that there is a large error in the cross-section measurement of the ground state and the first isomeric state due to the interference of the 121.78 keV energy level, whereas the theoretical values of the ground state and the second isomeric state are basically consistent with the existing experimental values. (authors)

[en] Atmospheric pressure dielectric barrier discharges (DBDs) have a wide range of industrial applications, generally exhibiting either filamentary or diffuse (i.e. glow) discharges. The focus of this investigation is on the formation mechanisms of the discharge current pulse width, on the order of tens of microseconds, accompanied by a light source formation, which is called a light source (LS) mode in air DBDs at atmospheric pressure. From a macroscopic point of view, the characteristics of the discharge current in the LS mode are similar with those of the glow mode. The optical and electrical characteristics of air DBDs at atmospheric pressure are investigated in the transition from the filamentary mode to the LS mode by measuring the optical emission spectroscopy and electrical signals. It is shown that in the manual increasing voltage stage, the vibrational temperature almost never changes and the gas temperature, electron temperature, dielectric capacitance, gas voltage (V_g) and discharge power (P) increase with an increase in the applied voltage. In the automatic decreasing voltage stage, all of these parameters, except V_g and P, increase with a decrease in the voltage. But, when the voltage decreases to a minimum value corresponding to the LS mode, P reaches a maximum value. In this paper, the variations of these parameters are analyzed and discussed in detail. The formation of the LS mode originates from the secondary electrons. The formation mechanisms of the secondary electrons are also discussed. (paper)

[en] Silicon is a very important material in many technological fields. It also has a complicated phase diagram of scientific interest. Here we reported a new allotrope of silicon obtained from crystal structure prediction. We studied its electronic, vibrational, dielectric, elastic and hardness properties by first-principles calculations. The results indicate that it is an indirect narrow-band-gap semiconductor. It is dynamically stable with a doubly degenerate infrared-active mode at its Brillouin zone center. Born effective charges of the constituent element are very small, resulting in a negligible ionic dielectric contribution. Calculated elasticity-related quantities imply that it is mechanically stable but anisotropic. There exist slowly increasing stages in the stress-strain curves of this crystal, which make it difficult to estimate the hardness of the crystal by calculating its ideal strengths. Taking advantage of the hardness model proposed by Šimůnek, we obtained a value of 12.0 GPa as its hardness. This value is lower than that of the cubic diamond-structural Si by about 5.5%. (paper)