I.G.Kim
,
I.S.Kim
金属学报(英文版)
Quasi-isotropic laminates have isotropic elastic properties in all yn-plane directions.Therefore,this kind of laminate is widely used for structural elements.The simplest stacking sequence of quasi-isotropic laminates is[0/-60/60]s.When the direction of applied axial lood to[0/-60/60]s laminate is inclined at a 30-degree angle,we have the other quasi-isotropic laminate [30/-30/90]s under axial load.The failure mecha-nisms of these two lamibnates are,however,entirely different from each other because these two laminates have different distribution of the interlaminar stresses.It was confirmed by tensile fatigue tests that the [0/-60/60]s laminate does not show any vis-ible fatigue damage,but the[30/-30/90]s laminate develops edge-delamination
关键词:
composite
,
null
,
null
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
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
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
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
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
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
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
左鸣
,
谭舜
,
于一
,
张志涛
,
皮雳
,
张庶元
低温物理学报
高温超导体的发现动摇了支配磁通动力学二十几年的Kim-Anderson模型.于是人们提出了新的涡旋玻璃态模型,集体钉扎模型和U～j对数关系模型来描述高温超导体的磁通动力学.其中,涡旋玻璃态模型已被人们广泛接受.Fe基超导体发现后,人们它行为十分类似于高温超导体.我们实验上仔细研究了FeSe0.5Te0.5单晶的V～I关系曲线,发现上述诸模型均不能很好的解释我们的实验结果,而张的反跳模型恰能很好的拟合实验结果.本文讨论了诸模型对高温超导体磁通动力学描述的适用性并给出合理的解释.
关键词:
高温超导体
,
磁通蠕动
,
涡旋钉扎
