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Observation of a Collective Oblate Band in 137Ce
ZHU Sheng-Jiang, ZHU Ling-Yan, LI Ming, GAN Cui-Yun, M. Sakhaee, YANG Li-Ming, ZHANG Zheng, JIANG Zhuo, LONG Gui-Lu, Jon Myang-Gil, WEN Shu-Xian, WU Xiao-Guang, LIU Xiang-An
Chin. Phys. Lett. 2000, 17 (7):
480-482
.
High spin states in 137Ce have been studied by using the heavy-ion induced reaction 124Sn(18O, 5n) carried out at China Institute of Atomic Energy. Partial level scheme with spin up to (43/2-), including a high spin collective rotational band observed for the first time, has been established. The collective band shows the properties similar to those oblate bands with γ~ -60o in neighboring nuclei and probably originates from the five quasi-particle configuration vsl/2 [vh11/2]2 πg7/2 πh11/2. The characteristics of this oblate band have been discussed.
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Experimental Study on High-Spin States in 119Xe
HUANG Wen-Xue, GUO Ying-Xiang, SUN Xiang-Fu, LEI Xiang-Guo, ZHOU Xiao-Hong, LIU Zhong, ZHANG Yu-Hu, ZHU Shao-Fei, XU Xiao, FENG Xi-Chen, LIU Ming-Yi, LUO Yi-Xiao, WEN Shu-Xian, WU Xiao-Guang, YUAN Guan-Jun, LI Guang-Sheng, YANG Chun-Xiang
Chin. Phys. Lett. 2000, 17 (7):
483-484
.
High-spin states of 119Xe have been investigated by in-beam y-ray spectroscopy via the reaction of l6O bombarding a 106Cd target at beam energies of 67-80MeV. No enhanced El transition was observed, the non-existence of octupole correlations in 119Xe.
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Domain Reversal Characteristics of Near-Stoichiometric LiNbO3 Crystals
YAO Jiang-Hong, XU Jing-Jun, ZHANG Guang-Yin, CHEN Xiao-Jun, LI Bing, LI Guan-Gao,
Chin. Phys. Lett. 2000, 17 (7):
513-514
.
The domain reversal characteristics of near-stoichiometric LiNbO3([Li]/[Li+Nb]=0.496) single crystals, which are grown by the Czochralski method with K2O flux, are investigated. The switch field for 180o ferroelectric domain reversal in the near-stoichiometric LiNbO3 crystal is 8.0±0.5kV/mm, which is only one third of the switching field required for the congruent LiNbO3 crystals. We have successfully achieved 180o domain reversal in near-stoichiometric LiNbO3 samples of 1.0 mm thickness.
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Effects of Plasma Density and Toroidal Magnetic Field on Lower Hybrid Current Drive Efficiency on HT-7 Tokamak
DING Bo-Jiang, KUANG Guang-Li, LIU Yue-Xiu, LIU Deng-Cheng,
ZHENG Guang-Hua, WU Jun-Shuan, LIU Fu-Kun, SHEN Wei-Ci,
LIN Jian-An, YANG Chun-Sheng, XU Han-Dong, YU Jia-Wen,
HUANG Yi-Yun, SHANG Lian-Quan, SHI Yue-Jiang, WU Zhen-Wei, ZHANG Jin-Song, YIN Fu-Xian, XIE Ji-Kang, WAN Yuan-Xi
Chin. Phys. Lett. 2000, 17 (7):
519-521
.
Lower hybrid current drive experiments on the HT-7 device have been carried out by scanning the following parameters: central line averaged electron density (ne = 0.6 - 2.0 x 1019m-3) and toroidal magnetic field (Bt = 1.62 - 2.0 T). The dependence of current drive efficiency on these parameters has been studied and the experimental curves of current drive efficiency as a function of ne and Bt have also been obtained. from these experimental results, it can be seen that current drive efficiency rises with the increase of toroidal magnetic field. As plasma density increases, the current drive efficiency first increases to a certain value, then gradually decreases, that is, there exists an optimized density regime where a better drive efficiency can be obtained. The analysis shows that the current drive efficiency is mainly affected by wave accessibility and impurity concentration, and the competition of these two factors determines the current drive efficiency.
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Cascade Energy Transfer in CeF3 Crystals
SHI Chao-Shu, DENG Jie, WE Ya-Guang, ZHANG Guo-Bin, G. Zimmerer, J. Becker, SHEN Ding-Zhong, HU Guan-qin
Chin. Phys. Lett. 2000, 17 (7):
532-533
.
The emission spectra of the CeF3 crystals in UV-visible region and their temperature dependence in the range of 6-453K under UV, VUV excitation as well as their excitation spectra (4-25eV) have been studied. The 350nm emission band from perturbed Ce3+ can be excited by 295.2 and 302.4nm emissions from the regular Ce3+. The 350nm emission band, in turn, can excite the emission bands centered at 470 and 535nm caused by some defects below room temperature. These results show that there is a cascade energy transfer process from regular Ce3+ to quenching centers via perturbed Ce3+ and defect centers in the CeF3. Meanwhile, thermoluminescence, giving peaks at about 240 and 300°C has been discovered, and the corresponding deep traps with depth~ leV are found to be a kind of quenching center for CeF3 luminescence at room temperature.
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A White Emitting Organic Diode with a Doped Blocking Layer
ZHANG Zhi-Lin, JIANG Xue-Yin, XU Shao-Hong
Chin. Phys. Lett. 2000, 17 (7):
534-536
.
A novel white emitting organic diode has been simply realized by inserting a doped hole-blocking layer between the hole transporting layer (HTL) and the electron transporting layer (ETL). The structure of this device is ITO/CuPc/NPB/blocking layer : rubrene/Alq/MgAg. Copper phthalocyanine(CuPc) was used as a buffer layer, N,N’-bis-(I-naphthy1)-N,N’-diphenyl-1,1’-bipheny1-4,4’-diamine (NPB) as the HTL, and trimer of N-arylbenzimidazoles (TPBi) as the blocking layers, in which rubrene is doped. Tris(8-quinolino1ato)aluminum complex(A1q) as ETL. Indium tin oxide and MgAg were the anode and cathode, respectively. The emission spectrum of this device covers a wide range of visible region and can be sensitively adjusted by the concentration of rubrene. The white emission with the CIE (Commission International de 1’ Eclairage) color coordinates x = 0.31, y = 0.32, a maximum luminance of 8635cd/m2, and the luminous efficiency 1.391m/W at the luminance of 100cd/m2 were obtained in the device with 1.5% rubrene concentration in TPBi.
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30 articles
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