Prediction of the Frontier Electronic States in a Finite Single-wall Carbon Nanotube

A theoretical model is summarized into the shorter vector principle. It is used to predict the topological structure of wave function and the oscillation rule of energy gap in various types of finite carbon nanotubes (CNTs). The theoretical model indicates that the characteristics of the electronic states only depend on the nanotube size and its symmetry along the shorter vector direction. In this direction, the wave functions of the original 3m (or 3m/2) periodicity are also suitable for armchair, chiral and zigzag finite CNTs with the C2 (Cs), C1 and Cn point groups, respectively. Energy gaps present the oscillation with 3m (or 3m/2) or odd-even n. The first principle calculations for some prototype systems are performed. The results are consistent with the theoretical model.     

《聚合物基复合材料》课程中的问题式学习

问题式教学是以增强问题意识和发现、分析和解决问题的能力为目的的教学模式。问题式教学对改变传统教学方式,培养学生发现、分析和解决问题的能力,形成创造力具有重要意义。吉尔福特的智力结构理论把智力分解成120个智力因子,有助于理解思维的基本属性。在聚合物基复合材料课程中把问题式教学和智力结构理论结合起来,针对不同的智力因子有目的性地设置问题,可以培养学生科学的思维方式,锻炼归纳、分析、联想等思维能力,提高学习和科研水平。     

Structure Analysis of Needle-like Copper Tantalum Trisulfide Crystals by XPS and Raman Spectroscopy

High-quality needle-like CuTaS3 single crystals have been synthesized through a chemical vapor transport(CVT)process.Crystallographic data show the special double chains of edge-sharing TaS6 octahedra....     

Association of UCP3, APN,and TNF-a Gene Polymorphisms with Type 2 Diabetes in a Population of Northern Chinese Han Patients

We observed the polymorphism distribution and coaction of uncoupling protein 3(UCP3)-55C/T,adiponectin(APN)+45T/G and tumor necrosis factor(TNF)-a-308G/A on the onset and development of T2DM in a North...     

Chain Conformation and Local Rigidity of Soluble Polyimides(Ⅱ): Isomerized Polyimides in THF

Two soluble isomerized polyimides(PIs)synthesized from 2,2′-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride(6FDA)with either 2,2′-dimethylbenzidine(2,2′-DMB)or 3,3′-DMB were investigated by means...     

火焰原子吸收光谱法测定赣南脐橙中6种微量元素含量

将赣南脐橙经硝酸和高氯酸消化后，在样品中加入氯化镧作为释放剂以消除共存离子的干扰，采用火焰原子吸收光谱法测定了Ca、Mn、Zn、Fe、Cu和Pb元素的含量。结果表明，标准加入法的回收率为．96．58％～104．31％，10次平行测定结果的相对标准偏差RSD均小于2％。该法灵敏度高、操作简便快速，结果准确，重现性好。可见赣南脐橙中各元素含量差异显著，其中ca的含量比较丰富，Mn、Fe和zn的含量中等，含有人体必需的微量元素，而对身体有害的元素如P11含量却相当低，这说明赣南脐橙具有一定的药用和经济价值，为进一步探讨赣南脐橙开发利用提供实际依据。     

氧化钨二氧化钛复合共生薄膜的拉曼光谱结构研究

采用电子束及真空热蒸发的方式镀制了氧化钨薄膜及掺杂的氧化钨的复合共生薄膜.运用拉曼光谱以及电化学工作站等测试手段分析了氧化钨复合共生薄膜的结构及电致变色性能.通过对拉曼光谱曲线的解叠分峰处理发现,源于晶相的810 cm-1拉曼峰的相对强度变化与样品的致色效率存在负相关,即拉曼峰相对强度越小,样品的致色效率越高.     

分子动力学模拟研究聚乳酸/聚酰胺11共混物的相容性

采用分子动力学(MD)模拟方法在COMPASS力场下,研究了不同质量比(10/90,30/70,50/50,70/30和90/10)聚乳酸(PLA)/聚酰胺11(PA11)共混物的相容性.研究结果表明:不同比例下PLA/PA11共混物的Gibbs自由能变化均大于零,其共混物很难形成均相体系;共混体系结合能的计算以及不同组分分子间C—C原子对径向分布函数的分析揭示了PLA和PA11的相互作用主要源自其分子间的范德华力;此外,模拟得到的所有比例下共混物的Flory-Huggins相互作用参数(χ)均大于临界Flory-Huggins相互作用参数(χcritical),进一步证明PLA与PA11不能形成相容体系。     

气相色谱-质谱法分析树苔浸膏的成分

采用分子蒸馏法对树苔浸膏进行分级分离,用气相色谱-质谱法对各级馏分进行定性和定量分析。结果表明:三级馏分共鉴定出55种成分,主要成分是苔黑酚单甲醚、分歧扁枝衣素单甲醚、扁枝衣酸乙酯、柔扁枝衣酸甲酯、β-苔黑酚羧酸甲酯、赤星衣酸乙酯、苔黑酚羧酸乙酯、柔扁枝衣酸乙酯、棕榈酸乙酯、油酸乙酯、亚麻酸乙酯和亚油酸乙酯。     

Deflagration-to-detonation transition process for spherical aluminum dust/epoxypropane mist/air mixtures in a large-scale experimental tube

The deflagration-to-detonation transitions (DDTs) for clouds of spherical aluminum dust (SAD) mixed with air or epoxypropane mist (EPM) and air were investigated in a 29.6-m-long experimental tube of 199 mm in diameter. The clouds formed through the injection of SAD and SAD/liquid epoxypropane samples into the experimental tube. Explosions of the SAD/air mixture were initiated using a 7-m-long EPM/air cloud explosion ignited by a 40-J electric spark. Explosions in SAD/EPM/air clouds were initiated using a 1...