The anomalous X-ray pulsar 4U 0142＋61 has been studied with obser- vations from INTEGRAL. The hard X-ray spectrum in the range 18-500 keV for 4U 0142＋61 was derived using nearly nine years of INTEGRAL/IBIS data. We ...The anomalous X-ray pulsar 4U 0142＋61 has been studied with obser- vations from INTEGRAL. The hard X-ray spectrum in the range 18-500 keV for 4U 0142＋61 was derived using nearly nine years of INTEGRAL/IBIS data. We ob- tained the average hard X-ray spectrum of 4U 0142＋61 with all available data. The spectrum of 4U 0142＋61 can be fitted with a power law that includes an exponen- tial high energy cutoff. This average spectrum is well fitted by a power law with r ,~ 0.51 ± 0.11 plus a cutoff energy at 128.6 ± 17.2 keV. The hard X-ray flux of the source from 20-150 keV showed no significant variations （within 20%） from 2003- 2011. The spectral profiles have some variability over the nine years such that the photon index varies from 0.3-1.5 and the cutoff energies from 110-250 keV. The de- tection of the high energy cutoff around 130 keV shows some constraints on the radia- tion mechanisms of magnetars and possibly probes the differences between magnetar and accretion models for this special class of neutron stars. Future HXMTobservations could provide stronger constraints on the hard X-ray spectral properties of this source and other magnetar candidates.展开更多
A circumstellar corona is proposed to explain a strange quark-cluster star during an accretion phase, which could be essential for understanding the observa- tions of the puzzling symbiotic X-ray system 4U 1700＋24. T...A circumstellar corona is proposed to explain a strange quark-cluster star during an accretion phase, which could be essential for understanding the observa- tions of the puzzling symbiotic X-ray system 4U 1700＋24. The state of cold matter at supranuclear density is still an important matter of debate, and one of the con- sequences of a strange star acting as a pulsar is the self-bound phenomenon on the surface, which makes extremely low-mass compact objects unavoidable. In principle, both the redshifted O VIII Ly-c~ emission line and the change in the blackbody radi- ation area could naturally be understood if 4U 1700＋24 is a low-mass quark-cluster star which exhibits wind accretion.展开更多
C_(86)H_(72)Cl_(20)Ni_6S_(12) , Mr = 2551. 62, monoclinic, space group C2/c, crystal data: a = 30. 322(5), b=14. 168(3), c=26. 453(4) A ,β=101. 00(4)°, V = 11155. 6 A3, Z=4, Dx=1. 519 g/cm3, λ(MoKα) = 0. 71069...C_(86)H_(72)Cl_(20)Ni_6S_(12) , Mr = 2551. 62, monoclinic, space group C2/c, crystal data: a = 30. 322(5), b=14. 168(3), c=26. 453(4) A ,β=101. 00(4)°, V = 11155. 6 A3, Z=4, Dx=1. 519 g/cm3, λ(MoKα) = 0. 71069 A ,μ=17. 370 cm-1, F(000) = 5152, T = 293 K, final R = 0. 078, Rw = 0. 086 for 5610 (I>3σ(I)) reflections. The crystal is composed of discrete [Ni (SCH2C6H4Cl-p)2]6 and CCl4 solvent molecules. The coordination geometries of the Ni atoms are perfect planes sharing S...S edges. The six NiS4 squares are linked with each other forming a hexagonal prism. The p-ClC6H4CH2S- side chains in the molecule are arranged in the axial and equatorial positions alternately with respect to the pseudo-hexagonal axis of the molecule.展开更多
The paper describes the solvent extraction of trace thorium from hydrochloric acid media by1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP) using a radioactive tracer technique. The percent extraction ofthorium was stu...The paper describes the solvent extraction of trace thorium from hydrochloric acid media by1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP) using a radioactive tracer technique. The percent extraction ofthorium was studied as a function of acidity, PMBP concentration and equilibrium time. The back-extraction behaviorof thorium from the organic phase was also tested. Separation of thorium was performed from fission products pro-duced in 14 MeV neutron bombardment of natural uranium by employing the PMBP extraction procedure. Thegamma-ray spectra of the separated thorium fractions show that thorium can be separated from most of fission prod-ucts and a large amount of uranium.展开更多
基金Supported by the National Natural Science Foundation of China
文摘The anomalous X-ray pulsar 4U 0142＋61 has been studied with obser- vations from INTEGRAL. The hard X-ray spectrum in the range 18-500 keV for 4U 0142＋61 was derived using nearly nine years of INTEGRAL/IBIS data. We ob- tained the average hard X-ray spectrum of 4U 0142＋61 with all available data. The spectrum of 4U 0142＋61 can be fitted with a power law that includes an exponen- tial high energy cutoff. This average spectrum is well fitted by a power law with r ,~ 0.51 ± 0.11 plus a cutoff energy at 128.6 ± 17.2 keV. The hard X-ray flux of the source from 20-150 keV showed no significant variations （within 20%） from 2003- 2011. The spectral profiles have some variability over the nine years such that the photon index varies from 0.3-1.5 and the cutoff energies from 110-250 keV. The de- tection of the high energy cutoff around 130 keV shows some constraints on the radia- tion mechanisms of magnetars and possibly probes the differences between magnetar and accretion models for this special class of neutron stars. Future HXMTobservations could provide stronger constraints on the hard X-ray spectral properties of this source and other magnetar candidates.
基金Supported by the National Natural Science Foundation of China
文摘A circumstellar corona is proposed to explain a strange quark-cluster star during an accretion phase, which could be essential for understanding the observa- tions of the puzzling symbiotic X-ray system 4U 1700＋24. The state of cold matter at supranuclear density is still an important matter of debate, and one of the con- sequences of a strange star acting as a pulsar is the self-bound phenomenon on the surface, which makes extremely low-mass compact objects unavoidable. In principle, both the redshifted O VIII Ly-c~ emission line and the change in the blackbody radi- ation area could naturally be understood if 4U 1700＋24 is a low-mass quark-cluster star which exhibits wind accretion.
文摘C_(86)H_(72)Cl_(20)Ni_6S_(12) , Mr = 2551. 62, monoclinic, space group C2/c, crystal data: a = 30. 322(5), b=14. 168(3), c=26. 453(4) A ,β=101. 00(4)°, V = 11155. 6 A3, Z=4, Dx=1. 519 g/cm3, λ(MoKα) = 0. 71069 A ,μ=17. 370 cm-1, F(000) = 5152, T = 293 K, final R = 0. 078, Rw = 0. 086 for 5610 (I>3σ(I)) reflections. The crystal is composed of discrete [Ni (SCH2C6H4Cl-p)2]6 and CCl4 solvent molecules. The coordination geometries of the Ni atoms are perfect planes sharing S...S edges. The six NiS4 squares are linked with each other forming a hexagonal prism. The p-ClC6H4CH2S- side chains in the molecule are arranged in the axial and equatorial positions alternately with respect to the pseudo-hexagonal axis of the molecule.
基金the National Natural Science Foundation of China(No.10075063 and 10175079)by the Chinese Academy of Sciences(TK95T-03)
文摘The paper describes the solvent extraction of trace thorium from hydrochloric acid media by1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP) using a radioactive tracer technique. The percent extraction ofthorium was studied as a function of acidity, PMBP concentration and equilibrium time. The back-extraction behaviorof thorium from the organic phase was also tested. Separation of thorium was performed from fission products pro-duced in 14 MeV neutron bombardment of natural uranium by employing the PMBP extraction procedure. Thegamma-ray spectra of the separated thorium fractions show that thorium can be separated from most of fission prod-ucts and a large amount of uranium.
