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[en] Purple gold (PG) has emerged as a colored gold product for use in decorating jewelry items. However, PG possesses little chemical stability in the ambient environments and undergoes noticeable decolorizing in a few months. This work uses the 4th harmonic Nd:YAG laser as a new measure instead of conventional coating technique to generate an anti-tarnishing layer on PG. The laser beam brings about instant melting at the irradiated surface of PG and re-solidification of the melt leads to a dense overlaying thin layer, of which the structure is contingent on the laser parameters and thermodynamic properties of the treated surface. This thin layer possesses very different properties from the non-irradiated surface. An investigation of laser-irradiation effect by varying its scanning speed and scanning repetitions were carried out to determine an optimal treatment condition. In conjunction with this investigation, scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive X-ray (EDX) were employed as well. The dependence of surface morphology and composition on the setting of parameters has been discovered through this work

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No abstract available

[en] The angular distribution of the ¹³C(d,p)¹⁴C reaction is reanalysed using the Johnson-Soper approach. The squared asymptotic normalization coefficient (ANC) of virtual decay ¹⁴C→¹³C + n is then derived to be 21.4 ± 5.0 fm^-1. The squared ANC and spectroscopic factor (SF) of ¹⁴O→¹³N + p are extracted to be 30.4 ± 7.1 fm^-1 and 1.94 ± 0.45, respectively. The astrophysical S-factors and reaction rates of ¹³N(p, γ)¹⁴O are determined from the ANC of ¹⁴O→¹³N + p using the R-matrix approach. (authors)

[en] The asymptotic normalization coefficients (ANCs) for the virtual decay ¹⁷O→¹⁶O+n are derived from the angular distributions of the ¹⁶O(d,p)¹⁷O reaction leading to the ground and first excited states of ¹⁷O, respectively, using the distorted wave Born approximation and the adiabatic wave approximation. The ANCs of ¹⁷F are then extracted according to charge symmetry of mirror nuclei and used to calculate the astrophysical S-factors of ¹⁶O(p, γ)¹⁷F leading to the first two states of ¹⁷F. The present results are in good agreement with those from the direct measurement. This provides a test of this indirect method to determine direct astrophysical S-factors of (p, γ)) reaction. In addition, the S-factors at zero energy for the direct captures to the ground and first excited states of ¹⁷F are presented, without the uncertainty associated with the extrapolation from higher energies in direct measurement. (authors)

[en] The asymptotic normalization coefficient of the virtual decay ²⁷P→²⁶Si + p is extracted to be 1840 ± 240 fm^-1 from the peripheral ²⁶Mg(d, p)²⁷Mg reaction using charge symmetry of mirror pair, for the first time. It is then used to derive the rms radius of the valence proton in the ground state of ²⁷P. The authors obtain the rms radius < r²>^1/2=4.57 ± 0.36 fm, significantly larger than the matter radius of ²⁷P. The probability of the valence proton outside the matter radius of ²⁷P is found to be 73%. The present work supports the conclusion that the ²⁷P ground state has a proton halo structure. (authors)

[en] Background: Fluorine (¹⁹F, the only stable F isotope) is a crucial element for nucleosynthetic studies since it is extremely sensitive to the physical conditions within stars. The astrophysical site of the production of fluorine is suggested to be asymptotic giant branch stars where the ¹⁵N(n, γ)¹⁶N reaction could affect the abundance of fluorine by competing with ¹⁵N(α, γ)¹⁹F. Purpose: The ¹⁵N(n, γ)¹⁶N reaction rate depends critically on the neutron spectroscopic factors of the four low-lying levels in ¹⁶N. Shell model calculations and two previous measurements of the (d, p) reaction yielded the spectroscopic factors with a discrepancy by a factor of ∼2. The present work aims to explore these neutron spectroscopic factors via an independent transfer reaction and to determine the stellar rate of the ¹⁵N(n, γ)¹⁶N reaction. Methods: The angular distributions of the ¹⁵N(⁷Li, ⁶Li)¹⁶N reaction leading to the first four states in ¹⁶N were measured using a high-precision Q3D magnetic spectrograph. The neutron spectroscopic factors and asymptotic normalization coefficients (ANC) for these states in ¹⁶N were then derived based on distorted wave Born approximation (DWBA) analysis. Results: The spectroscopic factors of these four states are extracted to be 0.96 ± 0.09, 0.69 ± 0.09, 0.84 ± 0.08 and 0.65 ± 0.08, respectively. The ¹⁵N(n, γ)¹⁶N reaction rate was derived based on the new spectroscopic factors. Conclusion: The present result demonstrates that two levels corresponding to neutron transfers to the 2s_1/2 orbit in ¹⁶N are not as good single-particle levels as the shell model expected. The present work also might provide an independent examination to shed some light on the existing discrepancies in the spectroscopic factors and the ¹⁵N(n, γ)¹⁶N rate. (authors)

[en] [Background] Data Archiver is an important part of the molten salt reactor control rod drive mechanism (CRDM) prototype control system. It is used to store real-time parameters, alarm and other information of equipment, etc., and accumulate data for further data-based prognostics and diagnostics. [Purpose] This study aims to develop a CRDM data Archiver based on PostgreSQL. [Methods] A dual-machine hot standby technique was employed to improve the performance of database and store data reliably. The control rod position retrieval tool was implemented by using Java programming. [Results] A Data Archiver based on PostgreSQL was developed and applied to CRDM prototype. [Conclusion] The Data Archiver designed based on PostgreSQL is proved to be an advanced, low cost and stable system. (authors)