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采用UF法精制I+G产品

张国俊 , 许赵辉 , 刘忠洲

膜科学与技术 doi:10.3969/j.issn.1007-8924.2002.02.010

采用截留分子量(MWCO)1万的卷式超滤膜和截留分子量(MWCO)6 000的中空纤维超滤膜,去除I+G粗品液中影响I+G产品透光的色素、大分子蛋白及可溶性胶体蛋白,不需加碳、压滤等工序,产品透光合格率达100%,产品透光的合格稳定性较现有生产工艺大大提高,该工艺不仅可以省去加碳压滤等工序,而且可以保证产品一次性达到合格产品.

关键词: 肌苷酸 , 鸟苷酸 , 超滤 , 透光

Studies of the EPR parameters g(i) and A(i) for Co2+ in the octahedral sites of Y3Al5O12 and Y3Ga5O12 crystals

Physica Status Solidi B-Basic Research

The perturbation formulas of EPR g factors g(\\) g(perpendicular to) and hyperfine structure constants A(\\) A(perpendicular to) for the trigonal octahedral 3d(7) cluster are derived considering not only the configuration interaction effect due to the admixture among ground and excited states, but also the covalency effect due to the admixture between the d electrons of the 3d(7) ion and the p electrons of ligands. In these formulas, the parameters related to both effects and the trigonal field parameters are estimated from the optical spectra and the structural parameters of the studied system. According to these formulas, the EPR parameters g(\\), g(perpendicular to), A(\\) and A(perpendicular to) for Co2+ in the octahedral sites of Y3Al5O12 and Y3Ga5O12 garnets are satisfactorily explained from the optical spectra and the structure data. The role of the covalency effect is discussed.

关键词: superposition model;phase-transition;absorption;linbo3;ions

Theoretical calculations of g factors and hyperfine structure constants for Co2+ in Cd2+(I) and Cd2+(II) sites of CsCdCl3 crystal

Communications in Theoretical Physics

The g factors g(parallel to), g(perpendicular to) and hyperfine structure constants A(parallel to), A(perpendicular to) for two trigonal Co2+ centers Co2+ in Cd2+(I) and Cd2+(II) sites) in CsCdCl3:Co2+ crystals are calculated from the high-order perturbation formulas based on the cluster approach. In the calculation, the contributions from covalency effect and configuration interaction effect are considered and the parameters related to both effects are obtained from the optical spectrum and the structure data of the studied system. The results are in good agreement with the observed values.

关键词: electron paramagnetic resonance;spin-Hamilton;crystal- and;ligand-field theory;Co2+;CsCdCl3;superposition model;ion

Energy spectra, g factors and their pressure-induced and/or thermal shifts of SrTiO3 : Cr3+ and SrTiO3 : Mn4+I: Energy spectra and g factors at normal pressure

Communications in Theoretical Physics

With the strong-field scheme and cubic bases, the complete d(3) energy matrix in a tetragonally distorted cubic-field has been constructed. By diagonalizing this matrix, the energy spectra of SrTiO3:Cr3+ and SrTiO3:Mn4+ at normal pressure and various temperatures have been calculated. Correspondingly, the FORTRAN program calculating the g factor of the ground state has been worked out. By using the program and the wave function obtained from diagonalizing the complete energy matrix, the g factors of the ground state of SrTiO3:Cr3+ and SrTiO3:Mn4+ at normal pressure and room temperature have been evaluated. The calculated results are in good agreement with the optical spectral and EPR experimental data. The comparison and analysis of the results of two crystals have been made. It is demonstrated that the covalency of the bonding between Mn4+ and ligands (O2-) in SrTiO3:Mn4+ is stronger than the one of the bonding between Cr3+ and ligands (O2-) in SrTiO3:Cr3+. It is shown that the obtained wavefunctions and values of parameters are reasonable.

关键词: crystal fields;energy spectrum;optical properties;g factors;covalency;ruby

G3镍基耐蚀合金管材热挤压工艺润滑行为研究 I. 玻璃润滑膜厚度模型建立及应用

王宝顺林奔张麦仓董建新

金属学报 doi:10.3724/SP.J.1037.2010.00511

研究了G3镍基耐蚀合金管材玻璃润滑热挤压工艺中润滑膜的成膜行为, 建立了润滑膜厚度的理论计算模型. 同时, 针对6000 t卧式挤压机, 结合G3合金热挤压工艺有限元模拟分析, 对热挤压工艺参数和玻璃润滑剂黏度进行了系统的研究. 结果表明, 可以通过玻璃润滑膜厚度及完成一次热挤压所需玻璃垫厚度的理论计算公式优化G3合金管材热挤压工艺参数, 并进一步获得了玻璃润滑剂黏度性质须满足: 玻璃粉的软化温度大约为720 ℃;在720-800 ℃, 玻璃黏温系数在-0.05 ℃-1和-0.04 ℃-1之间;热变形温度1100-1200 ℃区间的黏度为25-200 Pa?s.

关键词: 镍基合金 , hot extrusion , glass lubricant

爆炸复合LY12/20g双金属板疲劳裂纹扩展行为研究 I.面裂纹

崔建国 , 马莒生 , 傅永辉 , 李年 , 孙军 , 何家文

金属学报

考察了爆炸复合双层金属板LYl2/20g中界面两侧材料弹塑性失配对面裂纹疲劳扩展行为的影响.结果表明,当裂纹由弹性模量、屈服强度高的一侧向低的一侧扩展时,实际驱动力大于外加名义值;当裂纹由弹性模量、屈服强度低的一侧向高的一侧扩展时,实际驱动力小于外加名义值,从而造成裂纹扩展的加速或止裂,其影响离界面越近效果越显著,但弹性模量失配在裂纹开始扩展直至界面的过程中都起作用,而强度失配只在裂尖距界面一定距离范围内(Rp)才起作用.

关键词: LYl2/20g爆炸复合板 , null

爆炸复合LY12/20g双金属板疲劳裂纹扩展行为研究 I.面裂纹

崔建国 , 马莒生 , 傅永辉 , 李年 , 孙军 , 何家文

金属学报 doi:10.3321/j.issn:0412-1961.2001.12.007

考察了爆炸复合双层金属板LYl2/20g中界面两侧材料弹塑性失配对面裂纹疲劳扩展行为的影响.结果表明,当裂纹由弹性模量、屈服强度高的一侧向低的一侧扩展时,实际驱动力大于外加名义值;当裂纹由弹性模量、屈服强度低的一侧向高的一侧扩展时,实际驱动力小于外加名义值,从而造成裂纹扩展的加速或止裂,其影响离界面越近效果越显著,但弹性模量失配在裂纹开始扩展直至界面的过程中都起作用,而强度失配只在裂尖距界面一定距离范围内(Rp)才起作用.

关键词: LYl2/20g爆炸复合板 , 疲劳裂纹 , 弹塑性失配

Mode I and mixed mode I/II fatigue cracking in Ni3Al(CrB) single crystals

Fatigue & Fracture of Engineering Materials & Structures

Nominal mode I and mixed mode I/II fatigue tests were carried out using the intermetallic compound Ni3Al(CrB) in the form of single crystal specimens. The effects of crystal orientation and load mode on fatigue crack initiation and growth were studied. The fracture surfaces of the single crystals were characterized by a cleavage-like appearance and cracking occurred either on a single {111} plane or on multiple {111} planes irrespective of whether mode I or mixed mode I/II loadings were applied. It was found that the crack initiation and growth behaviour are dependent on both crystal orientation and applied loading mode. The cracking behaviour predicted by three mixed mode fracture criteria (MTS, SED and G criteria) in polycrystalline materials under mixed mode loading can be understood from the present results on single crystals.

关键词: fatigue cracking;mixed mode loading;crystallographic orientation;resolved shear stress;Ni3Al(CrB) single crystals;growth;alloy

Preparation of I_2 Clusters and Their Absorption Spectra

Zhaojun LIN , Zhanguo WANG , Wei CHEN and Lanying LIN(Lab. of Sendconductor Materials Science , Institute of Semiconductors , Chinese Academy of Sciences , Beijing 100083 , China)

材料科学技术(英文)

Samples have been prepared at different temperatures by loading I2 molecules into the cages of zeolite 5A, and the measurements of the absorption spectra have been carried out for the prepared samples. It is shown that I2 molecular clusters are formed in the cages of zeolite 5A,and it is also found that moIecuIar clusters which are bonded with intermoIecuIar forces have an important feature, namely, the intermolecular distance in molecular clusters can be changed on different preparing conditions and the blue shift of absorption edges can not be as the criterion of forming molecular clusters.

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