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Gamma Decay of the Lowly Excited States of 229AC
YUAN Shuang-gui, YANG Wei-fan, SHEN Shui-fa, FANG Ke-ming, MOU Wan-tong, ZHANG Xue-qian, LI Zong-wei
Chin. Phys. Lett. 1997, 14 (4):
263-265
.
By bombarding the natural thorium targets with 14 MeVneutrons, 229Ra was produced through the reaction 232Th(n,α) 229Ra. The radium activities were separated from the irradiated targets by coprecipitation with BaC12. A total of 18 weak γ rays with energies of 14.5, 15.6, 18.8, 21.8, 22.5, 44.0, 47.5, 55.0, 63.0, 69.6, 93.6, 94.1, 98.5, 102.2, 104.5, 106.1, 161.1, and 171.5keV, which could be assigned to the decay of 229Ra, has been observed in the isolated radium fractions employing high-resolution HPGe detectors and γ (x)- γ coincidence methods. A decay scheme of 229Ra based on these observations has been proposed.
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Production and Assignment of a New Transuranium Neutron-Deficient Isotope 235Am
SHI Li-jun, GUO Jun-sheng, LIU Hong-ye, GAN Zai-guo, YANG Wei-fan, MOU Wan-tong, GUO Tian-rui, SHEN Shui-fa, FANG Ke-ming, YUAN Shuang-gui, QIN Zhi, ZHANG Xue-qian, MA Rui-chang, ZHONG Ji-quan, WANG Shu-hong, KONG Deng-ming, QIAO Ji-min
Chin. Phys. Lett. 1997, 14 (4):
270-272
.
A new transuranium neutron-deficient isotope 235Am was produced via the reaction of 238Pu ( p , 4n) 235Am by using a 35 MeV proton beam. The recoiled products were collected by a helium-jet and long-capillary system. Americium isotopes were separated out by a rapid radiochemical method. X-ray, γ-ray, and x-γ coincidence measurements were taken in the study. According to 235Pu decay γ-ray and Np K x-ray growth-decay property, 235Am was definitely identified and its half life is determined as 15 ± 5 min.
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Structure and Raman Spectroscopy of Nanocrystalline TiO2 Powder Derived by Sol-Gel Process
ZHOU Qi-fa, WU Shang-hua, ZHANG Qing-qi, ZHANG Jin-xiu, CHEN Jian, ZHANG Wei-hong
Chin. Phys. Lett. 1997, 14 (4):
306-309
.
Nanocrystalline TiO2 powder was prepared by sol-gel process. The structures of the as-prepared and the TiO2 powder heat-treated at different temperatures were studied by thermogravimetric analyzer, differential thermal analysis, x-ray diffraction, and Raman spectra. As the powder was heat-treated at 350°C, it turned into tetragonal anatase structure. A structural transformation from anatase to rutile type occurred and the grains of the powder grew drastically when the powder was heat-treated at above 550°C. The structural transformation from anatase to rutile type completed at 750°C. The Raman spectra of TiO2 nanocrystalline powder were also studied.
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22 articles
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