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61.
The design and construction of Beijing Radioactive Ion-beam Facility (BRIF) was started at China Institute of Atomic Energy -CIAE) in 2004. In this project, a 100 MeV high intensity cyclotron, CYCIAE100, is selected as a driving accelerator for radioactive ion beam production. It will provide a proton beam of 75—100 MeV with an intensity of 200—500 μA. The scheme adopted in this design, i.e., stripping the accelerated H-, makes the structure more compact and construction cost much lower. At present, the design for each system has been accomplished. This paper depicts the basic physics design of the machine, including its major structure and parameters, beam dynamics and each relevant system, e.g. basic structure of the main magnet, numerical simulation of the RF resonant cavity, axial injection system, central region, and study on crucial physics problems concerning the extraction and beam lines. The major problems encountered during the design of CYCIAE-100 are also summarized in this paper. 相似文献
62.
Trends in the band-gap pressure coefficients and bulk moduli in different structures of ZnGa2S4, ZnGa2Se4 and ZnGa2Te4 下载免费PDF全文
We have performed a first-principles investigation for the family of compounds ZnGa2X4 (X = S, Se, Te). The properties of two possible structures, defect chalcopyrite and defect famatinite are both calculated. We reveal that ZnGa2S4 and ZnGa2Se4 have direct band gaps, while ZnGa2Te4 has an indirect band gap. The local density approximation band gaps are found to be very different in two structures, while the lattice parameters and bulk moduli are similar. We extend Cohen’s empirical formula for zinc-blende compounds to this family of compounds. The pressure coefficients are calculated and metallization pressures are discussed. We find that agi remains fairly constant when the group-Ⅵ element X is varied in ZnGa2X4 (Ⅱ-Ⅲ2 -Ⅵ4 ). 相似文献
63.
本文采用钼-铝-钼(Mo/Al/Mo)叠层结构作为源漏电极,制备氧化铟锌(IZO)薄膜晶体管(TFT).研究了Mo/Al/Mo源漏电极中与IZO接触的Mo层溅射功率对TFT器件性能的影响.随着Mo层溅射功率的增加,器件开启电压(Von)负向移动,器件均匀性下降.通过X射线光电子能谱(XPS)深度剖析发现IZO/Mo界面有明显的扩散;当Mo层溅射功率减小时,扩散得到了抑制.制备的器件处于常关状态(开启电压为0.5 V,增强模式),不仅迁移率高(~13 cm2·V-1·s-1),而且器件半导体特性均匀. 相似文献
64.
Chao Qian Zhen-Guo Fan Wei-Wen Zheng Run-Xin Bei Tian-Wen Zhu Si-Wei Liu Zhen-Guo Chi Matthew P.Aldred Xu-Dong Chen Yi Zhang Jia-Rui Xu 《高分子科学》2020,(3):213-219,I0005
High-performance low-k and low-loss circuit materials are urgently needed in the field of microelectronics due to the upcoming FifthGeneration Mobile Communications Technology(5 G Technology).Herein,a facile design strategy for non-fluorinated intrinsic low-k and low-loss polyimides is reported by fully considering the secondary relaxation behaviors of the polymer chains.A new amorphous non-fluorinated polymer(TmBPPA)with a k value of 2.23 and a loss tangent lower than 3.94×10^-3 at 104 Hz has been designed and synthesized,which to the best of our knowledge is the lowest value amongst the non-fluorinated and non-porous polymers reported in literature.Meanwhile,TmBPPA exhibits excellent overall properties,such as excellent thermostability,good mechanical properties,low moisture absorption,and high bonding strength.As high-performance flexible circuit materials,all these characteristics are highly expected to meet the present and future demands for high density,high speed,and high frequency electronic circuit used in 5 G wireless networks. 相似文献
65.
Nonlinear Dynamics - The tool of the discrete fractional calculus is introduced to discrete modeling of diffusion problem. A fractional time discretization diffusion model is presented in the... 相似文献
66.
The paper analyzes the nonlinear deformation of a current-carrying thin shell in coupled electromagnetic and mechanical fields.
The nonlinear magnetoelastic kinetic equations, physical equations, geometric equations, electrodynamic equations, expressions
for the Lorentz force of a current-carrying thin shell in a coupled field are given. The normal Cauchy form nonlinear differential
equations that include ten basic unknown functions are obtained by the variable replacement method. The difference and quasi-linearization
methods are used to reduce the nonlinear magnetoelastic equations to a sequence of quasilinear differential equations that
can be solved by discrete orthogonalization. Numerical solutions for the stresses and strains in a current-carrying thin strip
shell with two edges simply supported are obtained as an example. The dependence of the stresses and strains in the current-carrying
thin strip shell on the electromagnetic parameters is discussed. In a special case, it is shown that the deformation of the
shell can be controlled by changing the electromagnetic parameters 相似文献
67.
68.
Eight members of the Ag/1,2,4-triazole/polyoxometalates (POMs) hybrid supramolecular family, namely, [Ag4(dmtrz)4][Mo8O26] (dmtrz=3,5-dimethyl-1,2,4-triazole, 1), [Ag6(3atrz)6][PMo12O40]2.H2O (3atrz=3-amino-1,2,4-triazole, 2), [Ag2(3atrz)2]2[HPMoVI10MoV2O40] (3), [Ag2(dmtrz)2]2[HPMoVI10MoV2O40] (4), [Ag2(trz)2]2[Mo8O26] (trz=1,2,4-triazole, 5), [Ag2(3atrz)2][Ag2(3atrz)2(Mo8O26)] (6), [Ag4(4atrz)2Cl][Ag(Mo8O26)] (4atrz=4-amino-1,2,4-triazole, 7), and [Ag5(trz)4]2[Ag2(Mo8O26)].4H2O (8), were synthesized through hydrothermal reactions of 1,2,4-triazole or its derivatives with appropriate silver salts and molybdates. Crystal structure analysis reveals that the POM-dependent Ag-1,2,4-triazolate units in these hybrid compounds form a novel tetranuclear cluster (1), a unique double calix[3]arene-shaped hexamer (2), zigzag chains (5 and 6), helix chains (3, 4, and 8), and an interesting looped chain (7). A series of hydrogen bonding-based supramolecular assemblies varying among the 0-D+0-D (1 and 2), 0-D+1-D (3 and 4), 1-D+1-D (5 and 7), and 1-D+2-D (6) modes between the organomatic cations and POM anions were observed in these structures. Moreover, the inorganic chain [Ag(Mo8O26)]n3n- in 7 constructed by the building block [Mo8O26]4- linked only via single Ag+ ion is unprecedented. Compound 8 is the first high-dimensional framework constructed from the [Ag2(Mo8O26)]n2n- rod-shaped subunits. These hybrid supramolecular compounds present interesting photochemical properties. The spectroscopic experiments show that they not only are potential semiconductor materials but also have interesting photoluminescence phenomena, including O-->Mo [LMCT] and intraligand [pi-pi*] emissions generated by internal heavy metal effect. 相似文献
69.
醇盐水解法制备钛酸铅微粉的机理研究 总被引:1,自引:0,他引:1
采用TG-DTA、XRD、IR等手段研究了醇盐水解法制备的钛酸铅微粉的晶化行为,并用化学分析方法对微粉中可溶铅含量做了研究。结果表明,未昌化微粉中Pb以无定形PbTiO3和无定形PbO两种形式存在,当热处理温度达到晶化温度区间(430 ̄470℃)时,无定形PbTiO3向结晶型PbTiO3的转化和无定形PbO与TiO2间的反应同时发生。 相似文献
70.
反胶束是两亲分子在非极性溶剂中形成的一种有序组合体,在医药、化工、采油、胶束催化及酶催化等领域中有重要应用.与胶束溶液相比,人们对反胶束的形成与结构的了解至今仍不充分.特别是对于由混合表面活性剂形成的反胶束的研究几乎无人涉及.本文采用动态光散射、电导及荧光光谱等手段对阴离子表面活性剂AOT与非离子表面活性剂形成的混合反胶束进行了研究,旨在探讨利用表面活性剂的复配来调节和控制反胶束的结构和性能.亚实验部分二异辛基磺化琉璃酸钠(AOT,Sigma公司);Brij30为含4个氧乙烯基(EO基)的十二碳醇(AcrosOrgani… 相似文献