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Objectives The objective of the study is to investigate the relationships between Type 1 interferon (T1-IFN) signatures and clinical characteristics of lupus patients. Methods We examined 49 new-onset lupus patients who were diagnosed between 1999 and 2017. The patients treated with >10 mg of prednisolone or hydroxychloroquine were excluded from this study. Serum T1-IFN signatures were revealed by a functional reporter assay and standardized by recombinant IFN-α. Patient backgrounds, clinical findings, and treatments were retrospectively extracted from their electrical medical records. Clinical data were also available, including SLE Disease Activity Index of SLE patients on admission. Results T1-IFN signatures of lupus patients closely correlated with lupus disease activities, such as SLE Disease Activity Index-2K, white blood cell, C3 levels, and the titre of double-strand DNA antibody. We found fever and acute lupus dermatitis closely associated with T1-IFN signature. Conclusions In lupus patients, fever and acute lupus dermatitis are good indicators of a strong T1-IFN signature.

In this work, the compressive creep behaviors of hot-rolled pure Mg (0Y alloy) and various hot-rolled Mg-Y binary alloys (0.15Y, 1.5Y, 4.5Y, 7.5Y, and 10.5Y alloys) at 523 K were systematically studied under various applied stresses. These alloys all had an average grain size of ~100 μm. The loading directions were parallel to the rolling direction (RD), transverse direction (TD), and normal direction (ND). The creep behaviors were shown to exhibit an obvious dependence on the loading direction in the 0Y, 0.15Y, 1.5Y, and 4.5Y alloys. The creep resistance had a sequence of ND > TD ≥ RD in these alloys. The creep anisotropy of the alloys was caused by 〈a〉 dislocation cross-slipping from the basal plane to the prismatic plane and { $$ 10\bar{1}2 $$ } twinning dominating the creep along the RD and TD, while dislocation climb and pyramidal 〈c + a〉 slip prevailed along the ND. Compared to the 0Y, 0.15Y, and 1.5Y alloys, the more random basal texture in the 4.5Y alloy weakened the cross-slip and twinning along the RD and TD and triggered cross-slip along the ND, resulting in decreased creep anisotropy. For the 7.5Y and 10.5Y alloys, an approximate creep isotropy due to cross-slip and pyramidal 〈c + a〉 slip dominated the creep along all three loading directions. Moreover, compared to the 0Y alloy, the creep resistance was found to be slightly increased in the 0.15Y alloy and significantly increased with increasing the Y content above 1.5 wt pct, which can be attributed to solution strengthening and the promoted pyramidal 〈c + a〉 dislocations collaboratively increasing the creep resistance. The improved hindering effect on twinning also helped to increase the creep resistance along the RD and TD. In addition, dynamic precipitation strengthening assisted the increment of creep resistance in the 10.5Y alloy. Thus, the addition of concentrated Y in Mg alloys is a valid solution to eliminate the compressive creep anisotropy and simultaneously enhance the creep resistance.

We studied thermal evolution of isolated neutron stars (NSs) including the pion condensation core, with an emphasis on the stiffness of equation of state (EOS). Many temperature observations can be explained by the minimal cooling scenario which excludes the fast neutrino cooling process. However, several NSs are cold enough to require it. The most crucial problem for NS cooling theory is whether the nucleon direct Urca (DU) process is open. The DU process is forbidden if the nucleon symmetry energy is significantly low. Hence, another fast cooling process is required in such an EOS. As the candidate to solve this problem, we consider the pion condensation. We show that the low-symmetry-energy model can account for most cooling observations including cold NSs, with strong neutron superfluidity. Simultaneously, it holds the $2~M_{\odot}$ observations even if the pion condensation core exists. Thus, we propose the possibility of pion condensation, as an exotic state to solve the problem in low-symmetry-energy EOSs. We examined the consistency of our EOSs with other various observations as well., 21 pages, 8 figures, accepted by Int. J. Mod. Phys. E

A compressive pre-straining of 0.05 was applied to two Mg–2Y alloy sheets with different initial textures along their normal directions. Creep behaviors of these sheets before and after the pre-straining were investigated at 493 K under stresses ranging from 20 to 100 MPa. The influence of pre-straining on creep behaviors was then discussed. The results show that the effects of pre-straining on creep behaviors of the two sheets are quite different. A profound strengthening effect of this pre-straining is observed on the creep resistance of the extruded sheet with creep strain decreased by half and steady strain rate reduced by 75% at most. By contrast, for the rolled sheet, the improvement of creep resistance by the pre-straining is negligible. The difference lies in the number of anomalous twins introduced by the pre-straining. After the pre-straining, considerable {10–12} anomalous twins have been introduced in the extruded sheet with a random initial texture, compared to the rolled one. Dislocation movements during the creep can be impeded by the large amounts of twins in the pre-strained extruded sheets, resulting in the obvious improved creep resistance. Meanwhile, different predominant dislocation mechanisms are found along different creep directions. Since a more excellent impeding effect of the twins is obtained on cross-slip, better improvement of the creep resistance can be achieved along the TD than along the ED of the pre-strained extruded sheet.

Compressive creep anisotropic behaviors were observed for a hot-extruded Mg–3Al–1Zn alloy rod at 423 K. Heavy basal slip accelerated the creep rate along transverse and 45° directions. Inversely, strong interactions between high densities of prismatic dislocations and {10–12} twins enhanced the creep resistance along extrusion direction. Although twinning was reported to induce yield softening during uniaxial loading, it could be beneficial for creep resistance even applied stress over yield stress.

We model the quiescent luminosity of accreting neutron stars with several equation of states (EOSs), including the effect of pion condensation and superfluidity. As a consequence of comparison with the observations, we show that the results with Togashi EoS (the strong direct Urca process is forbidden) and TM1e EoS (mass at direct Urca process is $2.06 M_\odot$) can explain the observations well by considering pion condensation and the effect of superfluidity, while LS220 EoS and TM1 EoS can explain the observations well by considering the baryon direct Urca process and the effect of superfluidity. Besides, we compare the results with the observations of a neutron star RX J0812.4-3114 which has the low average mass accretion rate ($\langle\dot{M}\rangle\sim(4-15)\times 10^{-12}~M_\odot ~\rm yr^{-1}$) but high thermal luminosity ($L_q^\infty\sim(0.6-3)\times10^{33}~\rm erg ~ s^{-1}$), and we suggest that a low-mass neutron star ($, 12 pages, 8 figures, accepted by Phys. Rev. D

We study the quiescent luminosities of accreting neutron stars by a new mechanism as neutrino heating for additional deep crustal heating, where the neutrino heating is produced by charged pions decay from the nuclear collisions on the surface of neutron star during its active accretion. For low mass neutron star($\lesssim1.4~M_{\odot}$), as the neutrino heating is little($\lesssim1$ MeV per accreted nucleon) or there would be no neutrino heating, the quiescent luminsoity will be not affected or slightly affected. While for massive neutron star ($\gtrsim2~M_{\odot}$), the quiescent luminosity will be enhanced more obviously with neutrino heating in the range 2-6 MeV per accreted nucleon. The observations on cold neutron stars such as 1H 19605+00, SAX J1808.4-3658 can be explained with neutrino heating if a fast cooling and heavy elements surface are considered. The observations on a hot neutron star such as RX J0812.4-3114 can be explained with neutrino heating if the direct Urca process is forbidden for a massive star with light elements surface, which is different from the previous work that the hot observations should be explained with small mass neutron star and the effect of superfluidity., Comment: 9 pages, 5 figures, accepted for publication in Phys. Rev. D

As some neutron star transients require an additional unknown heat source (referred to as “shallow heating”) to explain their high temperatures at the beginning of quiescence, we investigate the effect of shallow heating as well as compressional heating on the thermal state of transiently accreting neutron stars with the use of evolutionary calculations in the present work. Through comparing our theoretical predictions of the equilibrium redshifted luminosities $(L_{\gamma}^{\infty})$ produced by both deep crustal heating and shallow heating/compressional heating for different time-averaged mass-accretion rates $\langle\dot{M}\rangle$ with 35 updated observations of soft X-ray transients, the results show that both shallow heating and compressional heating make significant contributions to the equilibrium redshifted luminosity. The hotter sources (XTE J1701, MAXI J0556, EXO 0748, Aql X-1 etc.) with higher accretion rates are more likely to be explained with the effect of shallow heating or compressional heating. In addition, for a proper shallow heat $q_\mathrm{sh}$ and mass-accretion rate $\dot{M}$, the effect of shallow heating could be simulated by compressional heating.

We have proposed a short-lived radioisotope 98Tc as the nuclear cosmochronometer to evaluate the time from the last supernova neutirno-process to the solar system formation (SSF). We have calculated the supernova neutirno-process using a SN 1987A model with neutrino-induced reaction cross sections. The calculated result is consistent with the observed upper limit of 98Tc/98Ru at the SSF.

We investigate X-ray bursts during the thermal evolution of an accreting neutron star which corresponds to the X-ray burster GS\ 1826-24. Physical quantities of the neutron star are included using an equation of state below and above the nuclear matter density. We adopt an equation of state and construct an approximate network that saves the computational time and calculates nuclear energy generation rates accompanying the abundance evolutions. The mass and radius of the neutron star are got by solving the stellar evolution equations from the center to the surface which involve necessary information such as the nuclear energy generation in accreting layers, heating from the crust, and neutrino emissions inside the stellar core. We reproduce the light curve and recurrence time of the X-ray burst from GS 1826-24 within the standard deviation of 1$\sigma$ for the assumed accretion rate, metallicity, and equation of state. It is concluded that the observed recurrence time is consistent with the theoretical model having metallicity of the initial CNO elements $Z_{\rm CNO}$ = 0.01. We suggest that the nuclear reaction rates responsible for the $rp$-process should be examined in detail, because the rates may change the shape of the light curve and our conclusion., Comment: 11 pages, 11 figures, accepted for publication in PTEP

We calculate the abundances of 7Li, 11B, 92Nb, 98Tc, 138La, and 180Ta produced by neutrino (ν)-induced reactions in a core-collapse supernova explosion. We consider the modification by ν self-interaction (ν-SI) near the neutrinosphere and the Mikheyev–Smirnov–Wolfenstein (MSW) effect in the outer layers based on time-dependent neutrino energy spectra. Abundances of 7Li and the heavy isotopes 92Nb, 98Tc, and 138La are reduced by a factor of 1.5–2.0 by the ν-SI. In contrast, 11B is relatively insensitive to the ν-SI. We find that the abundance ratio of heavy to light nuclei, 138La/11B, is sensitive to the neutrino mass hierarchy, and the normal mass hierarchy is more likely to be consistent with the solar meteoritic abundances.

We investigate the significance of isomers on a kilonova associated with neutron star mergers (NSMs) for the first time. We calculate the evolution of abundances and energy generation rates ($\dot{\epsilon}_{\rm nuc}$) of ejecta from NSMs, taking into account $\beta^-$ decay through isomers. We find that for ejecta with electron fraction ($Y_e$) of $0.2-0.3$, $\dot{\epsilon}_{\rm nuc}$ is appreciably changed from those without isomers, due to the large change in timing of $\beta^-$ decay through the isomeric states of ${}^{123, 125, 127} \rm Sn$ and ${}^{128} \rm Sb$. In particular, the effects of the isomers on $\dot{\epsilon}_{\rm nuc}$ are prominent for ejecta of $Y_e \sim 0.25$, which could emit a fraction of an early, blue component of a kilonova observed in GW170817. When the excitation from a ground state to its isomeric state is important, the isomers of ${}^{129} \rm Sb$ and ${}^{129, 131} \rm Te$ also cause additional and appreciable change in $\dot{\epsilon}_{\rm nuc}$. Furthermore, we demonstrate that larger amounts of lanthanide-free ejecta result in a better fit of an observed light curve of the kilonova in GW170817 if the isomers are taken into account., Comment: 6 pages, 4 figures. Accepted for publication in MNRAS

We study the effects of nuclear equation of state (EOS) on Type-I X-ray bursts, focusing on the Clocked burster GS 1826–24. According to the shell-flush model, the surface gravity of the neutron stars (NSs) strengthens burst activities, where the recurrence time and peak luminosity are higher for larger-radius EOSs. We show that such a prediction matches with the full multi-zone model, in which whole NS regions are considered in burst calculation. We also show that the large-radius EOSs are not preferred to account for the observed light curves of GS 1826–24.

Neutron stars are high-density objects formed by the gravitational collapse of massive stars, and the whole star can be likened to a giant nucleus. The interior of a neutron star is considered to contain exotic particles and states which do not appear in a normal nucleus. The internal states are constrained by observations of masses and radii via the equation of state of highly dense nuclear matter. Within these constraints, a variety of exotic states have been discussed. The internal state of neutron stars is closely related to its neutrino emission process, which cools the star from the inside. This effect can be compared with observations of the surface temperature of neutron stars. However, despite the wide range of observations of neutron stars, the nature of the neutron star matter remains uncertain. We consider quark matter as an exotic state and perform cooling calculations for neutron stars, incorporating the effects of nucleon superfluidity and quark colour superconductivity.We take into account the “quark-hadron continuity”, in which the neutron superfluidity is succeeded by thedquark pairing. Furthermore, we obtained the range of the neutron star cooling curve, taking into account the difference in surface temperature due to the composition of the surface layer. We found that the existence of quark matter causes strong neutrino emission from quarks, which is moderately suppressedbysuperfluidity and superconductivity, and canexplain the cold surface temperature of neutron stars.

The short-lived unstable isotopes with half-lives of 0.1–10 My have been used as nuclear cosmochronometers to evaluate from an astrophysical event such as supernova (SN) explosion or AGB s-process to the solar system formation. We have proposed shorted-lived radioisotopes of 92Nb and 98Tc as the nuclear cosmochronometers for supernova neutrino-process

This study investigates the impacts of artificial aging state on the tensile creep resistance of a hot-rolled Mg-3.5 wt%Nd alloy. The alloy was heat treated under different conditions, including solution treatment at 490 °C, under-aging for 2, 5, and 10 h, and peak-aging for 20 h at 220 °C. The samples were abbreviated as AS, A2, A5, A10, and A20, respectively. After aging for 2 h, many precipitates appeared in the under-aged A2 sample, most of which were lenticular β ′ -phase precipitates. With an increasing aging duration, β ′ transitioned to β 1 and substantial solute depletion was observed. The A2 sample had no precipitate-free zone (PFZ), but PFZs formed in A5, widened in A10, and evolved into the widest in the peak-aged A20 sample. During creep testing at 250 °C, β 1 phases precipitated in the AS sample, and atomic diffusion induced the formation and widening of PFZs. Pyramidal dislocations and β 1 dissolution induced grain boundary migration and rapid PFZ widening in the A20 sample, which was less obvious in the A10 and A5 samples. The slightest solute depletion in the grain boundaries during artificial aging and the unconspicuous β 1 dissolution during creep testing avoided fast PFZ widening in the A2 sample. Consequently, although the A20 sample had the highest strength at room temperature, wide PFZs and grain boundary migration led to severe stress concentration and deteriorated its creep resistance. Narrow PFZs and dislocations cutting the β ′ phases in the A2 sample led to the best creep resistance.

Whether fast cooling processes occur or not is crucial for the thermal evolution of neutron stars. In particular, the threshold of the direct Urca process, which is one of the fast cooling processes, is determined by the interior proton fraction $Y_p$, or the nuclear symmetry energy. Since recent observations indicate the small radius of neutron stars, a low value is preferred for the symmetry energy. In this study, simulations of neutron star cooling are performed adopting three models for the equation of state (EoS): Togashi, Shen, and LS220 EoSs. The Togashi EoS has been recently constructed with realistic nuclear potentials under finite temperature, and found to account for the small radius of neutron stars. As a result, we find that, since the direct Urca process is forbidden, the neutron star cooling is slow with use of the Togashi EoS. This is because the symmetry energy of Togashi EoS is lower than those of other EoSs. Hence, in order to account for observed age and surface temperature of isolated neutron stars with the use of the Togashi EoS, other fast cooling processes are needed regardless of the surface composition.

Both static precipitation and dynamic precipitation could hardly enhance the creep resistance of dilute Mg-Nd alloys. To solve this problem, the present paper proposed a practical method, which was combining pre-compression and subsequent peak-aging. A binary Mg-1.5 wt%Nd alloy plate, was prepared for researching the tensile creep behaviors at 523 K. Due to the aging hardening was weak, the directly aged sample was not studied. The pre-compressed sample was named PC sample, and the pre-compressed with subsequent peak-aged sample was named PC-AA sample, while the sample without any pre-compression or aging was named NPC sample. The PC-AA sample had the best creep resistance, followed by the NPC sample, and the PC sample had the poorest. For the NPC sample, twinning and dislocation slip (including basal slip, cross-slip and pyramidal slip) jointly controlled the creep behavior. Various creep mechanisms led to the easy creep strain increment and the poor creep resistance. In regard to the PC sample, the thermal stability of the preset twins was inferior and twin widening happened, resulting in a faster increment in the creep strain and a poorer creep resistance. With respect to the PC-AA sample, the dominant creep mechanisms were basal slip and dislocation climb. The high-density particles inside the preset twins successfully delayed cross-slip and twin widening, leading to the enhanced creep resistance. Thus, the twins induced by the pre-compression and the particles inside the twins induced by the subsequent peak-aging successfully enhanced the creep resistance of the dilute Mg-Nd alloys.

This work proposed a practical method, interrupted compression with an intermediate annealing, for optimizing the mechanical properties of Mg–4Y-2Nd-0.2Zn-0.5Zr alloy. This method contained the first compressive step for an interrupted strain of 0.25, the intermediate annealing for 5 min, and the second compressive step for a total true strain of 1.6. The temperatures for the two steps of hot compression and intermediate annealing were the same. The obtained sample was named IC sample. As a comparison, the continuous compression was also performed (CC sample). During hot compression, the work softening of the CC sample was dominated by the rotational dynamic recrystallization (rDRX) and the twin-assisted DRX (tDRX). With the strain increasing, the rDRX acted a more dominant role compared to the tDRX. In the IC sample, the intermediate annealing triggered the formation of deformation bands. During the second compressive step of the IC sample, the work softening was dominated by the DRX assisted by deformation bands besides the rDRX. As a result, the volume fraction of ultra-fine grains (VUFG) was much higher in comparison to the CC sample. Compared to the grain size of UFGs (DUFG) and the basal pole distribution, the VUFG had a more important role in the resultant mechanical properties. The higher VUFG of the IC sample led to the better combination of strength and ductility at each compressive temperature. Comparing the IC sample to the CC sample after compressing at temperatures from 420 °C to 510 °C, the increments of the UTS were 7.4%, 2.4%, 1.2% and 0.4%, and the increments of the FE were 4.0%, 13.9%, 22.8% and 21.3%. The interrupted compression with an intermediate annealing had a deep potential in applying to other Mg alloys despite the initial texture.

In this work, the tensile creep anisotropy was investigated in a hot-rolled Mg-5.5 wt%Y alloy sheet. The loading directions were performed along rolling, transverse and normal directions (RD, TD and ND), respectively. The results showed that a poor creep resistance was obtained along ND due to serious stress concentration induced by high-density twin boundaries blocking dislocations. While a similarly excellent creep resistance was obtained along RD and TD due to pyramidal slip contributes to the strain hardening during creep process. Meanwhile, this work found that an addition of 5.5 wt%Y could enhance the crack resistance of grain boundary over that of twin boundary. When twin boundaries were heavily generated to block dislocations during tensile creep, crack initiation occurred rapidly. It is suggested that both the density of twin boundaries and the Y content should be considered for improving the creep resistance of Mg Y based alloys.

The deformation behaviors of a hot-extruded Mg-2wt%Y alloy sheet with high activity for basal slip was studied under uniaxial tensile loading along the extrusion direction at room temperature. Using electron backscatter diffraction and crystal plasticity finite element method (CPFEM) simulation, this work proposed the direct evidence for the activation and the role of anomalous { 10 1 ‾ 2 } twinning: (1) In the Mg alloy with high activity for basal slip, anomalous { 10 1 ‾ 2 } twins were indeed identified during tensile loading rather than unloading. The anomalous twins had the highest or the third highest negative Schmid factors of { 10 1 ‾ 2 } twinning, while the normal twins had positive Schmid factors. (2) During tensile loading, the anomalous twins were more easily activated than normal twins. As the true strain increased, the amounts of anomalous twins increased faster than the amounts of normal twins. (3) The normal twins induced positive shear strain along the loading direction while the anomalous twins induced negative shear strain along the loading direction. The role of anomalous twinning was accommodating the plastic compatibility and improving the ductility.

Mg-RE based alloys usually exhibit better creep resistance than traditional RE-free Mg alloys. Creep anisotropy can be still found in Mg-RE alloys but barely investigated. Thus, in the present study, tensile creep anisotropy and creep mechanisms were studied in a dilute Mg-2Y alloy extruded sheet. It is found that tensile creep property shows not only obvious stress and temperature dependences but also strong anisotropy. Varied stress exponent n is obtained under different conditions. Under σ 40 MPa at all temperatures, n > 4 is seen and intense dislocation slip becomes the predominant deformation mode. Besides, steady-state strain rate e ˙ s and n are always higher along ED than TD. This creep anisotropy is caused by different dislocation slip types. Basal slip plays the most important role in the creep anisotropy under σ 40 MPa. Heavy basal slip and pyramidal slip are the main mechanism during the creep along ED while cross-slip of dislocations plays the dominant role along TD. Furthermore, { 10 1 ‾ 2 } anomalous twins are more likely to be found in samples crept along ED with a smaller Schmid factor for twinning. Anomalous twinning and pyramidal slip contribute to the creep fracture of ED sample. Unlikely, cross-slip composed by basal and prismatic dislocations induces the fracture of TD sample.

The creep properties of a hot-compressed Mg-9Gd-4Y-0.5Zr alloy with different volume fractions (VFs) of fine grains were investigated at 523 K, 548 K and 573 K. Based on the initial VFs of fine grains, the samples were divided into four groups including VF0 (VF = 0), VF0.2 (VF = 20%), VF0.5 (VF = 50%) and VF0.8 (VF = 80%) samples. The VF0.8 sample had the highest yield stress at room temperature, followed by the VF0.5 and VF0.2 samples, and the VF0 sample had the lowest. But after creep tests, the VF0.2 and VF0.5 samples had better creep resistance compared to the VF0 and VF0.8 samples at all the three temperatures. The creep life was shortest for the VF0 sample due to its lowest yield stress. The VF0.2 and VF0.5 samples were dominated by dislocation climb and pyramidal slip during creep testing. Deformation bands formed by pyramidal dislocations and obvious dynamic precipitation strengthened the creep resistance. Besides, the serrated grain boundaries were formed by the combination of coarse and fine grains, which absorbed dislocations and further improved the creep resistance. The VF0.8 sample was weakened by the precipitate-free zones (PFZs) formed along the high densities of grain boundaries. Although fine grains could improve yield stress, the excessive fine grains deteriorated the creep resistance owing to the heavy appearance of PFZs. Fortunately, the creep properties were successfully enhanced in this work through introducing mixed microstructures with both coarse and fine grains.

We investigate the nuclear abundances uniquely produced from the neutrino neutrino-process in super-nova (SN) explosion. For the first time, we have calculated the neutrino propagation including both its modification by neutrino-self-interaction (neutrino-SI) near the neutrino-sphere and the Mikheyev-Smirnov-Wolfenstein (MSW) mixing in the outer layers. We compute the neutirno-induced nucleosynthesis of 7Li, 11B, 92Nb, 98Tc, 138La, and 180Ta. Near to the neutirno-sphere, the neutrino-density is very high neutirno-SI becomes important. The interaction effect on the neutirno-process is calculated by solving the evolution equation for the neutirno-density matrix with a collision term estimated in the mean field approximation as well as the MSW (neutrino matter oscillations) in the outer layers of the SN. The light element abundances turn out to be increased by the MSW effect, but the neutirno-SI suppresses the MSW effect in the inverted hierarchy scheme. As a result, the ratio of 7Li/11B becomes lower than that of the normal hierarchy, which is consistent with more recent analysis of the meteoritic ratio.

Tensile creep tests were performed at 523 K on a hot compressed Mg-2.5 wt%Nd binary alloy with peak aging (AA sample) and without aging (AS sample) in this work. The dominant creep mechanisms of AS sample were dislocation climb and pyramidal slip while AA sample was mainly dominated by cross-slip. During creep testing, only plate-like β1 precipitate was formed in AS sample while both plate-like β1 and lenticular β′ phases were formed in AA sample. Moreover, AA sample had larger scale and higher density of precipitates compared to AS sample. Besides, precipitate-free zones (PFZs) were clearly observed along grain boundaries of both AS and AA samples during their secondary creep stages. And the width of PFZs was narrower in AA sample than that in AS sample. The narrower PFZs, the higher density of β1 and β′ phases, and the strong interactions between cross-slip and precipitates effectively enhanced the creep properties of AA sample. As a result, AA sample behaved higher creep resistance in comparison to AS sample under all applied stresses at 523 K. Thus, this method of pre-aging and hot compression is believed to have deep potential in improving the service performance of Mg–Nd series at medium to high temperatures.

The effects of pre-compression on the creep behaviors along rolling direction (RD), transverse direction (TD) and normal direction (ND) of a hot-rolled Mg-4wt%Y alloy sheet were investigated in this study. A valid and convenient method for enhancing creep resistance and a systematic research in understanding creep anisotropy were provided. The pre-compression was carried out at 298 K along TD and performed to a true strain of 0.07. The samples with pre-compression (PC) and without pre-compression (NPC) were labeled as NPC-RD, NPC-TD, NPC-ND and PC-RD, PC-TD, PC-ND, respectively. Compressive creep tests along different directions were carried out at 523 K under various applied stresses. The results showed that both NPC and PC samples had obvious a three-dimensional creep anisotropy. The sequence of creep resistance of NPC samples was ND > TD > RD. The dominant creep mechanisms of NPC-RD and NPC-TD samples were both cross-slip and twinning. While dislocation climb and pyramidal slip dominated the creep of NPC-ND sample, resulting in the highest creep resistance among the three NPC samples. After pre-compression, the resultant sequence of creep resistance of PC samples was RD > ND > TD. Dislocation climb and frequent twin intersections became the dominant creep mechanisms and significantly enhanced the creep resistance of PC-RD sample. Due to detwinning, only a slight enhancement of creep resistance happened in PC-ND sample. The creep resistance in PC-TD sample perceptibly declined, because heavy cross-slip and stepped dislocations accelerated the creep strain. Although the three-dimensional creep anisotropy still insisted in PC samples, pre-compression was manifested to be an excellent method for improving creep properties along the worst direction (RD).

In this work, Mg-xY-2Nd-0.2Zn-0.5Zr (x = 0, 2, 4, 6 and 8, in weight percentage) alloys were subjected to hot compression at various temperatures from 420 °C to 510 °C. For briefness, the studied alloys were named as 0Y, 2Y, 4Y, 6Y and 8Y samples. During hot compression, dynamic recrystallization (DRX) happened and ultra-fine grains (UFGs) were generated in all samples. With the increase of Y content, the volume fraction of UFGs became lower. Based on the origins of work softening during hot compression, the samples could be classified into two groups. Low Y-containing group included 0Y, 2Y and 4Y samples, while high Y-containing group included 6Y and 8Y samples. Continuous DRX (cDRX), which was accompanied by deformation bands, induced the work softening of low Y-containing samples. Inversely, for high Y-containing samples, high-density dynamic precipitates consumed the stored energy and induced the work softening. The cDRX development was delayed, and discontinuous DRX (dDRX) happened at the dynamic precipitate sites at high strains. For the hot-compressed samples, during uniaxial tensile tests at room temperature, basal slip dominated low Y-containing samples while pyramidal slip dominated high Y-containing samples. The strong interactions between pyramidal dislocations and precipitates enhanced the strength of high Y-containing samples by sacrificing elongation.

The isotope $^{98}\mathrm{Tc}$ decays to $^{98}\mathrm{Ru}$ with a half-life of $4.2\ifmmode\times\else\texttimes\fi{}{10}^{6}\text{ }\text{ }\text{ }\mathrm{yr}$ and could have been present in the early Solar System. In this Letter, we report on the first calculations of the production of $^{98}\mathrm{Tc}$ by neutrino-induced reactions in core-collapse supernovae (the $\ensuremath{\nu}$ process). Our predicted $^{98}\mathrm{Tc}$ abundance at the time of solar system formation is not much lower than the current measured upper limit raising the possibility for its detection in the not too distant future. We show that, if the initial abundance were to be precisely measured, the $^{98}\mathrm{Tc}$ nuclear cosmochronometer could be used to evaluate a much more precise value of the duration time from the last core-collapse supernova to the formation of the solar system. Moreover, a unique and novel feature of the $^{98}\mathrm{Tc}$ $\ensuremath{\nu}$-process nucleosynthesis is the large contribution ($\ensuremath{\sim}20%$) from charged current reactions with electron antineutrinos. This means that $^{98}\mathrm{Tc}$ becomes a unique new $\ensuremath{\nu}$-process probe of the temperature of the electron antineutrinos.

We provide some useful formulas explicitly to obtain the Einstein tensor as a convenience to readers. We also establish our notation in tensor calculus.

We summarize physical and astronomical constants in cgs units. We also provide the conversion of peculiar units in nuclear physics and astronomy used in this book.

Concerning the decrease in the cosmological term Λ from a large magnitude in a very early universe to a small value at the present epoch, we explore the Brans-Dicke theory modified with a variable Λ term which is a function of the scalar field. The fundamental equations are derived for the gravitational and scalar fields from the variational principle of the action. In the framework of the Robertson-Walker metric, we obtain the expression for the expansion rate of the universe like the Friedmann equation. Then we turn to summarize the observational constraints on the intrinsic parameters contained in this theory. We confirm that the evolution of the universe deviates significantly from the standard model in the early stage. Calculations of Big Bang nucleosynthesis (BBN) are performed with the use of the nuclear reaction network. Comparing the resultant amounts of the light elements,4He, D, and 7Li, with the observed primordial abundances and using also the magnitude-redshift relation of Type Ia supernovae (SNe Ia), we derive reasonable ranges of the parameters.

Many alternative models are proposed, though remarkable agreement is obtained on the primordial abundance of standard BBN. As an approach to nonstandard models, first we investigate a possibility that neutrinos or antineutrinos are degenerate. An excess density of neutrinos speeds up the expansion of the universe, leaving more neutrons at the onset of nucleosynthesis. In addition, degenerate electron-neutrinos shift less neutrons through β-equilibrium. Performing χ2 analysis for the calculated and observed abundances of 4He and D, we determine the plausible ranges of the degeneracy parameter and the baryon-to-photon ratio. Next, we explore BBN under the brane-world cosmology. The Friedmann-like equation is derived in the five-dimensional universe. It is found that more 4He is produced than in standard BBN because of rapid expansion due to the interaction energy on the brane. Finally, we examine thermal evolution in the early universe including a decaying cosmological term which is treated as a source of the gravitational field.

We mention the fundamentals in the theory of general relativity, i.e., the principles of equivalence and general covariance. Based on the facts that our universe is homogeneous and isotropic at large scales, we derive the Robertson-Walker metric and subsequently the Friedmann equation which governs the expansion of the universe. The equation is expressed in a convenient form in terms of density parameters. Next, we describe thermonuclear reaction rates utilized in astrophysics, which involve resonant and nonresonant reactions, photodisintegration, electron capture, and β-decay. We review the significance of standard Big Bang nucleosynthesis (SBBN) and summarize the current situation in the observed primordial abundance of light elements,4He, D, and 7Li. Comparing the calculated abundance of the elements with observed values, we determine a reasonable range for the baryon-to-photon ratio. Moreover, we examine the dependence of the produced amount of 4He on the measured lifetimes of neutrons. Finally, we consider the magnitude-redshift relation of type Ia supernovae (SNe Ia) as an independent probe to cosmological models.

We review the recent progress in the Big-Bang nucleosynthesis which includes the standard and nonstandard theory of cosmology, effects of neutrino degeneracy, and inhomogeneous nucleosynthesis within the framework of a Friedmann model. As for a nonstandard theory of gravitation, we adopt a Brans–Dicke theory which incorporates a cosmological constant. We constrain various parameters associated with each subject.

Aspergillus niger and its related species, known as Aspergillus section Nigri , are ubiquitously distributed across the globe and are often isolated from clinical specimens. In Japan, Aspergillus section Nigri is second most often isolated from clinical specimens following Aspergillus fumigatus . We determined the species of Aspergillus section Nigri isolated in Japan by DNA sequencing of partial β-tubulin genes and investigated drug susceptibility by the CLSI M38-A2 method. The collection contained 20 Aspergillus niger , 59 Aspergillus welwitschiae , and 39 Aspergillus tubingensis strains. Drug susceptibility testing revealed 30 to 55% of A. niger , 6.8 to 18.6% of A. welwitschiae , and 79.5 to 89.7% of A. tubingensis isolates to be less susceptible (so-called resistant) to itraconazole (ITC) and/or voriconazole (VRC) according to the epidemiologic cutoff values (ECVs) proposed for A. niger previously. MIC distributions of ITC or VRC showed no remarkable differences between clinical and environmental isolates. When the cyp51A sequences were compared between susceptible and resistant strains, 18 amino acid mutations were specific for resistant isolates of A. niger and A. tubingensis ; however, none of them were confirmed to be associated with azole resistance. Three nonrelated A. welwitschiae isolates possessed a partial deletion in cyp51A , likely attributable to being more susceptible to azoles than other isolates. One of five ITC-resistant A. tubingensis isolates showed higher expression of cyp51A than did susceptible strains. Our results show that cyp51A point mutations may have no association with azole resistance but that in some cases the overexpression of cyp51A may lead to the azole resistance in these species.

MAXI J0556-332 is the hottest transient accreting neutron star at the beginning of its quiescence. A theoretical model with crustal heating indicates that an additional shallow heat source of Qshallow > 6 MeV per accreted nucleon is required in the shallow outer crust with respect to the deeper star crust by considering the observed decline in accretion rate at the end of outburst. However, the physical source of this shallow heating is still unclear. In the present investigation, we performed stellar evolutionary calculations, adopting the effects of outburst behavior of the accretion rate. As a consequence, we find that the quiescent light curve of MAXI J0556-332 can be well explained by the nuclear energy generation due to the hot CNO cycle., 9 pages, 2 figures