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。     

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.     

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.     

The extent of linkage disequilibrium in Arabidopsis thaliana.

Linkage disequilibrium (LD), the nonrandom occurrence of alleles in haplotypes, has long been of interest to population geneticists. Recently, the rapidly increasing availability of genomic polymorphism data has fueled interest in LD as a tool for fine-scale mapping, in particular for human disease loci. The chromosomal extent of LD is crucial in this context, because it determines how dense a map must be for associations to be detected and, conversely, limits how finely loci may be mapped. Arabidopsis thaliana is expected to harbor unusually extensive LD because of its high degree of selfing. Several polymorphism studies have found very strong LD within individual loci, but also evidence of some recombination. Here we investigate the pattern of LD on a genomic scale and show that in global samples, LD decays within approximately 1 cM, or 250 kb. We also show that LD in local populations may be much stronger than that of global populations, presumably as a result of founder events. The combination of a relatively high level of polymorphism and extensive haplotype structure bodes well for developing a genome-wide LD map in A. thaliana.     

系统发育史的重建

不同的物种是怎样进化形成不同的形态 ,这仍是现代进化生物学中研究的主要课题。近年来 ,对这一问题的研究已集中在由于进化时间的不同而导致进化机制变化的模型上 ,并在解开机体发育期间控制形态表现的分子机理方面取得了惊人的进展。值得注意的是 :形态的表型和一些调节基因的突变大致反映了物种间所表现的差异。通过分析生物的系统发育 ,重新构建系统发育史 ,可以阐明控制发育过程和进化发育的相关时间的遗传网络的分子进化机制。与系统发育进化有关的信息影印在组成它们的基因片段上。存在于这些发育位点的信息可以使人们追踪到发育调节…     

合并财务报表中合并范围的确定

首先介绍了判断控制的两种标准：定量标准与定性标准，然后通过分析使用定量标准确定合并范围的不足，得出合并范围的确定庆以定性标准为主，定量标准为辅的结论。并构造了流程图来说明两种标准的具体应用。     

应用激光闪光法测量薄膜材料的热扩散率

目的是将用于测量片状试样的热扩散率的激光闪光法推广至测量薄膜试样。应用 1 5纳秒脉冲 Nd:YAG激光及响应时间 0 .9微秒的 (Hg,Cd) Te红外探测器等建立了闪光法热扩散率测量系统 ,并应用此系统对微米量级厚度的不锈钢薄膜进行了测量。同时针对将激光闪光法应用于薄膜时所出现的问题 ,如激光的有限脉冲时间及有限吸收厚度效应 ,测量系统的滞后效应 ,以及增强红外吸收及辐射用表面黑化膜的影响进行了分析并提出了解决方法     

Superoxide activates mitochondrial uncoupling proteins.

Uncoupling protein 1 (UCP1) diverts energy from ATP synthesis to thermogenesis in the mitochondria of brown adipose tissue by catalysing a regulated leak of protons across the inner membrane. The functions of its homologues, UCP2 and UCP3, in other tissues are debated. UCP2 and UCP3 are present at much lower abundance than UCP1, and the uncoupling with which they are associated is not significantly thermogenic. Mild uncoupling would, however, decrease the mitochondrial production of reactive oxygen species, which are important mediators of oxidative damage. Here we show that superoxide increases mitochondrial proton conductance through effects on UCP1, UCP2 and UCP3. Superoxide-induced uncoupling requires fatty acids and is inhibited by purine nucleotides. It correlates with the tissue expression of UCPs, appears in mitochondria from yeast expressing UCP1, and is absent in skeletal muscle mitochondria from UCP3 knockout mice. Our findings indicate that the interaction of superoxide with UCPs may be a mechanism for decreasing the concentrations of reactive oxygen species inside mitochondria.     

Microbial desulfurization of fuel oil

Culture conditions of desulfurization microbes were investigated with a bioreactor controlled by computer.Factors such as pH, choice of carbon source, optimal concentrations of carbon, nitrogen and sulfur sources were determined. The addition of carbon in a culture with a constant pH greatly improved the growth of Rhodococcus. Cells and cell debris from microbes rested using a sulfur- specific pathway were used to desulfurize diesel oil treated by hydrodesulfurization (acquired from the Research Institute of Fushun Petroleum with total sulfur level at 205 μg/mL).Strains 1awq, IG, X7B, ZT, ZCR, and a mixture of No. 5 and No. 6, were used in the biodesulfurization process. The reduction of total sulfur was between 10.6% and 90.3%.