[en] The shapes of superheavy nuclei have been investigated using Total-Routhian-Surface calculations in a multidimensional space including both even- and odd-multipolarity deformations. Particularly, we have discussed in detail possible shape coexistence in Fm and No isotopes where normally-deformed rotational bands have been observed experimentally. It is found that the heights of fission barriers can be significantly reduced due to the inclusion of odd-multipolarity deformations. In some neutron-deficient superheavy nuclei, there are shallow superdeformed minima with fission barriers less than 3 MeV.

[en] Gas-water interfacial plasmas under water were generated in a compact space in a tube with a sandglass-like structure, where two metal wires were employed as electrodes with an applied 35 kHz ac power source. The dynamic behaviors of voltage/current were investigated for the powered electrode with/without water cover to understand the effect of the gas-water interface. It is found that the discharge exhibits periodic pulsed currents after breakdown as the powered electrode is covered with water, whereas the electrical current reveals a damped oscillation with time with a frequency about 10⁶ Hz as the powered electrode is in a vapor bubble. By increasing water conductivity, a discharge current waveform transition from pulse to oscillation presents in the water covering case. These suggest that the gas-water interface has a significant influence on the discharge property.

[en] Thrust measurements were performed on a coil made of a YBa₂Cu₃O_7-δ coated conductor acting as the excitation system of a single-sided linear synchronous motor. The superconducting coil was a single pancake in the shape of a racetrack with 100 turns, the width and effective lengths were 42 mm and 84 mm, respectively. The stator was made of conventional copper wire. At 77 K and a gap of 10 mm, with an operating direct current of I_DC = 30 A for the superconducting coil and alternating current of I_AC = 9 A for the stator coils, a thrust of 24 N was achieved. With addition of an iron core, thrust was increased by 49%. With addition of an iron back-plate, thrust was increased by 70%.

[en] The Rossi X-Ray Timing Explorer (RXTE) has made hundreds of observations on three famous young pulsars (PSRs) B0531+21 (Crab), B1509–58, and B0540–69. Using the archive RXTE data, we have studied the phase-resolved spectral properties of these pulsars in details. The variation of the X-ray spectrum with phase of PSR B0531+21 is confirmed here much more precisely and more details are revealed than in the previous studies: The spectrum softens from the beginning of the first pulse, turns to harden right at the pulse peak and becomes the hardest at the bottom of the bridge, softens gradually until the second peak, and then softens rapidly. Different from the previous studies, we found that the spectrum of PSR B1509–58 is significantly harder in the center of the pulse, which is also in contrast to that of PSR B0531+21. The variation of the X-ray spectrum of PSR B0540–69 seems similar to that of PSR B1509–58, but with a lower significance. Using about 10 years of data span, we also studied the real time evolution of the spectra of these pulsars, and no significant evolution has been detected. We discuss the constraints of these results on theoretical models of pulsar X-ray emission.

[en] Thermal X-ray emission from young supernova remnants (SNRs) is usually dominated by the emission lines of the supernova ejecta, which are widely believed to be crossed and thus heated by the inward-propagating reverse shock (RS). Previous works using X-ray imaging data have shown that the ejecta are heated by the RS by locating the peak emission region of the most recently ionized matter, which is found to be well separated toward the inside from the outermost boundary. Here we report the discovery of a systematic increase of the Sulfur (S) to Silicon (Si) Kα line flux ratio with radius in Tycho’s SNR. This allows us, for the first time, to present continuous radial profiles of the ionization age and, furthermore, the elapsed ionization time since the onset of the ionization, which gives the history of the propagation of the ionization front into the SNR ejecta

[en] Multilayers consisting of two tetragonal compositions PbZr_0.2Ti_0.8O₃ and PbZr_0.4Ti_0.6O₃ were deposited onto a SrRuO₃ electrode grown on a vicinal (1 0 0) SrTiO₃ substrate. It has been shown by extensive structural investigations comprising transmission electron microscopy in conventional and high resolution mode, reciprocal space mapping and piezoresponse force microscopy that with decreasing layer thickness a transition from a-domains confined to individual layers to a-domains propagating through the whole film takes place. This is caused by the formation of a common strain state of all layers which is responsible for the observed enhancement of the electrical properties. These show a maximum in the product of remanent polarization and dielectric constant at a certain density of interfaces. If the interface density becomes too high the lattice distortion accompanying each interface deteriorates the properties of the multilayer structure.

[en] Using the archival data from the Rossi X-ray Timing Explorer, we study the evolution of the Crab pulsar's X-ray profile in a time span of 11 years. The evolutionary trends of the X-ray profile are similar to that observed in radio, but with quantitative differences. Finally, we briefly discuss the constraints of these X-ray properties on the geometry of the emission region of this pulsar.

[en] We propose that a nonthermal X-ray arc inside the remnant of Tycho's supernova (SN) represents the interaction between the SN ejecta and the companion star's envelope lost in the impact of the explosion. The X-ray emission of the remnant further shows an apparent shadow casted by the arc in the opposite direction of the explosion site, consistent with the blocking of the SN ejecta by the envelope. This scenario supports the single degenerate binary origin of Tycho's SN. The properties of the X-ray arc, together with the previous detection of the companion candidate and its space velocity by Ruiz-Lapuente et al. and Hernandez et al., enable us to further infer that (1) the progenitor binary has a period of 4.9^+5.3_-3.0 days, (2) the companion gained a kick velocity of 42 ± 30 km s^-1, and (3) the stripped envelope mass is about 0.0016 (≤0.0083) M_sun. However, we note that the nature of the companion candidate is still under debate, and the above parameters need to be revised according to the actual properties of the companion candidate. Further work to measure the proper motion of the arc and to check the capability of the interaction to emit the amount of X-rays observed from the arc is also needed to validate the current scenario.

[en] The excitation spectra of nuclei in the regions 150< A<190 and 220< A<250 are commonly considered as showing characteristics of the rotational motion. In the present work, however, there is evidence indicating that the nuclei can evolve from rotation to vibration. We have used two simple models to discuss the collective motions of a nucleus for different spin ranges. In addition, in order to get the insight into the rotational-like properties of nuclei, as an example, shape calculations using the total Routhian surfaces (TRS) model have been carried out for positive-parity states in ¹⁵⁶Gd. Also we have shown the result of the nucleus ¹⁰²Ru which is given as an example of the reverse transition, i.e., vibration to rotation. The TRS plots reveal that, with increasing spin, the former nucleus becomes slightly soft in γ and β deformations, while the latter one becomes rigid in the γ deformation

[en] High-temperature nanoindentation was used to reveal nano-layer size effects on the hardness of two-dimensional metallic nanocomposites. We report the existence of a critical layer thickness at which strength achieves optimal thermal stability. Transmission electron microscopy and theoretical bicrystal calculations show that this optimum arises due to a transition from thermally activated glide within the layers to dislocation transmission across the layers. We demonstrate experimentally that the atomic-scale properties of the interfaces profoundly affect this critical transition. The strong implications are that interfaces can be tuned to achieve an optimum in high temperature strength in layered nanocomposite structures