数值学报（2003年第12卷）

本书是由英国剑桥大学出版、发行的不定期专题论文集，每年出版一卷，登载数值分析、计算方法及其应用等方面的高水平创造性研究论文或综述报告，论文作者多为当代相关领域的国际性学术带头人。     

Application of microfluidic chip to realize controllable pH gradient

A kind of PH gradient microfluidic chips through soft-lithography microfabrication for isoelectric focusing (IEF) and high performance liquid chromatography (HPLC) is introduced here. These pH gradient chips have the advantages such as easy fabrication, controllable pH range and precision, isoelectric focusing and separation at the same time, low voltage for isoelectric focusing, and time stable pH gradient. This method has potential application to sample preparation, separation and analysis of microfluidic chips.     

半导体热电材料Bi1-xSbx薄膜的电化学制备

B I1-XSBX半导体合金是性能优异的热电和磁电功能材料,为制备固态电制冷器件、温差发电器件和磁电器件的重要材料。电化学沉积薄膜技术工艺设备简单成本低,在半导体薄膜制备方面有很好的应用前景。系统研究了高浓度盐酸(2.4 MOL/L)的B I和SB盐酸溶液,成份从纯铋逐步变化到纯锑的B I1-XSBX合金半导体薄膜电化学沉积特性。测试了沉积过程I-V循环曲线和和沉积电荷效率等电化学参数。结果表明在所有成份范围内都可以得到典型的B I1-XSBX固溶体结构的高质量薄膜。薄膜生长为典型的溶液扩散控制过程,具有高的沉积电荷效率。薄膜沉积和溶解之间的电位差随溶液中SB(Ⅲ)离子浓度增加而增大,生长的薄膜越来越稳定。在30%SB浓度附近,电化学过程、薄膜结构和性能发生明显的突变。应用X射线衍射和电子显微镜研究薄膜结构,发现薄膜具有明显的(012)择优取向,薄膜晶粒尺寸也随SB浓度的增加而变化。     

Rare earth effect of yttrium on formation and property of Cr_2O_3 oxide film formed on Co-Cr binary alloy

The isothermal oxidizing kinetics of Co-40Cr alloy and its yttrium ion-implanted samples were studied at 1000 ℃ in air by thermal-gravity analysis (TGA). Scanning electronic microscopy (SEM) was used to examine the Cr2O3 oxide film's morphology after oxidation. Secondary ion mass spectrum (SIMS) method was used to examine the binding energy change of chromium caused by Y-doping and its influence on formation of Cr2O3 film. Acoustic emission (AE) method was used in situ to monitor the cracking and spalling of oxide films formed on both samples during oxidizing and subsequent air-cooling stages. Theoretical model simulating the film fracture process was proposed to analyze the acoustic emission spectrum both on time domain and on AE-event number domain. It is found that yttrium ion-implantation can remarkably reduce the isothermal oxidizing rate of Co-40Cr and improve the anti-cracking and anti-spalling properties of Cr2O3 oxide film. Reasons for the improvement are mainly that the implanted yttrium can reduce the grain size of Cr2O3 oxide, increase the high temperature plasticity of oxide film, and remarkably reduce the number and size of Cr2O3/Co-40Cr interfacial defects.     

Microbial starch-binding domains are superior to granule-bound starch synthase I for anchoring luciferase to potato starch granules

Microbial starch-binding domains (SBD) and granule-bound starch synthase I (GBSSI) are proteins which are accumulated in potato starch granules. The efficiency of SBD and GBSSI for targeting active luciferase reporter proteins to granules during starch biosynthesis was compared. GBSSI or SBD sequences were fused to the N- or C-terminus of the luciferase (LUC) gene, via an artificial Pro-Thr encoding linker sequence. The genes were introduced into an amylose-free (amf) potato mutant. It appeared that SBD was superior to GBSSI as a targeting sequence, mainly because the luciferase retained higher activity in the SBD-containing fusion proteins than in the GBSSI-containing ones.     

宏观面内剪切作用下多尺度裂纹模型的耦合闭合解

裂纹在面内剪切荷载作用下,宏观应力场呈反对称分布,微观应力场将不再具有反对称性,可能是面内拉伸与面内剪切的混合型分布.另外,考虑微观裂纹前还有一个刃型位错区,据此建立起一个多尺度嵌套的裂纹模型,可以描述从原子尺度下的刃型位错区过渡到Ⅰ、Ⅱ复合型微观裂纹,再过渡到Ⅱ型宏观裂纹.材料不同尺度下的损伤,通过约束过渡区相连接,引入尺度变换因子的概念,并利用位移连续性条件与应力场匹配条件,求解出多尺度耦合问题的闭合形式的解.通过数值计算,讨论了材料宏观力学性能对不同尺度下各影响因素的的敏感性.研究结果表明,材料破坏机理非常复杂,与作用荷载、不同尺度下缺陷的几何形状、尺寸及材料性能等因素相关.     

作为非物质文化遗产的南涧彝族“跳菜”

本文根据衡量非物质文化遗产的四条标准：具有突出的历史、文化和科学价值；具有展现中华民族文化创造力的典型性和代表性；具有在一定群体中世代传承、活态存在的特点；具有鲜明特色，在当地有较大影响。结合南涧彝族“跳菜”的实际情况进行比照分析，得出了南涧彝族“跳菜”是一种非物质文化遗产的结论。     

Accelerated carbonation and leaching behavior of the slag from iron and steel making industry

Ground granulated blast furnace slag(GGBFS)and steelmaking slag have been used as a raw material for cement production or as an aggregate to make concrete,which contribute aluminum,calcium,iron,and silicon oxides.The suitability of the slag for a particular application depends on its reactivity,cost,availability,and its influence on the properties of the resulting concrete.For the interest of durability studying of concrete in the presence of slag,the accelerated carbonation products and leaching behavior of the slag and Portland cement(PC)were studied.The experimental results confirmed that the slag was more resistant to carbonation compared to PC.The carbonation degree of GGBFS reduced by 17.74%;and the carbonation degrees of steelmaking slags reduced by 9.51%-11.94%.Carbonation neutralized the alkaline nature of the hydrated pastes and gave rise to the redox potential of the leachate slightly(30-77 mV).The carbonation also increased the release of most of the elements presented,except for calcium,to the aqueous environment.It is concluded that blend cements(PC plus slag)have economical advantages and better durability compared to PC.