Theoretical studies of C36 encapsulated in zigzag single-wall carbon nanotubes

Discovery of carbon nanotubes (CNTs) has attracted considerable attention in the scientific community due to their unique structures and properties. Chemical doping can further modify the electrical properties of CNT. The empty space inside CNT provides t…     

芳香族多硝基类化合物电子结构的量子化学研究

用ＭＩＮＤＯ／３方法研究了一些芳香族多硝基化合物的电子结构，这些化合物的几何构型参数均用能量梯度方法优化，在此基础上利用Ｍｕｌｌｉｋｅｎ布局分析所得到的电荷，重叠布局等比较好地解释了这些化合物的Ｘ光电子能谱和其他性质。     

几种杂环与芳环半导体高聚物的电子结构

用自洽场晶体轨道方法,在能量梯度优化单胞所得几何构型的基础上,研究了3种含硫(或氮)杂环与芳环共聚的高聚物半导体材料的电子结构.由于这些高聚物中杂环与芳环的非共面性,使得它们的能带结构中带宽较窄,带隔较大,在未掺杂时为绝缘体物质.但它们的电离势大小与聚乙炔相应值接近,故是较好的P型半导体材料.     

微穿孔板吸声结构在阶梯教室中的应用

依据马大猷教授的微穿孔板基本理论，进行参数选择并设计了微穿孔吸声反射板结构，用于阶梯教室中，分析了这种微穿孔吸声反射板结构在阶梯教室中的声反射和声吸收的性能。     

斜发沸石岩膨胀可控性的研究

以相应的盐溶液处理嫩江斜发沸石岩，将其改为ＮＨ４＋、Ｋ＋、Ｎａ＋、Ｃａ＋＋及某种混合型，发现在相同的焙烧制度下，每种阳离子型沸石都具有其独特的膨胀率范围，据此，得出斜发沸石岩的膨胀可控性，并提出烧制优质轻骨料的沸石岩化学成分范围。     

Molecular orbital study on antiferromagnetic coupling mechanism in a silver （Ⅰ） complex

The mechanism of antiferromagnetic coupling in an Ag （Ⅰ） complex of nitronyl nitroxide is investigated by means of the broken-symmetry approach within the density functional method （DFT-BS）. The magneto-structural correlation and the single-occupied molecular orbital （SOMO） analysis reveal the existence of the antiferromagnetic coupling pathway along nitronyl nitroxide units via Ag （Ⅰ） ion, and that the Ag （Ⅰ） ion plays an important bridge role. The spin population analysis also shows the existence of spin delocalization along the ONCNO-Ag-ONCNO chain. It is found that the non-typical covalent bonds with major ionic character between Ag （Ⅰ） ions and oxygen atoms of nitronyl nitroxide units can be used to mediate the spin-spin interaction of nitronyl nitroxides.     

Ag/TiO_2/AC光催化氧化NO性能研究

以活性炭(AC)为载体,采用溶胶-凝胶法和浸渍法制备新型光催化剂Ag/TiO_2/AC,利用SEM、XRD、BET和UV-Vis光谱等手段对样品进行了表征,并以模拟烟气中的NO为对象,进行光催化氧化性能测试。结果表明,Ag/TiO_2/AC的比表面积为895.21 m~2/g,且对光响应波长已扩展到可见光区,该催化剂在光催化氧化NO反应中具有优异的活性,NO的氧化率高于60.5%。     

顺式聚乙炔衍生物取代基效应的理论研究

用自洽场晶体轨道法(SCF-CO)讨论了顺式聚乙炔取代衍生物的取代基效应。研究表明,这些取代衍生物仍存在带隔。吸电子基团(-CN,-F)的取代使体系的电子亲合势和电离势增大,而给电子基团(-CH_3,-NH_2)的取代,则使体系的电离势降低。     

酸性气田产水气井产能计算方法

普光气田主体为带边底水的酸性气藏,在开发过程中,凝析水的析出和边底水的侵入将影响气井产能,另一方面,天然气中的酸性气体对气井产能计算有一定影响,因此,准确确定产水气井产能显得尤其重要。鉴于没有实用的方法计算酸性气田产水气井产能,在修正高含硫气体基本物性参数的基础上,从无水气井产能方程出发,利用气水相对渗透率曲线、气井产水率、生产水气比的关系,修正表皮系数,从而计算出酸性气田产水气井的产能。该方法不仅能够快速地对气井产水后的产能进行计算分析,还能够预测未来不同生产水气比时气井产能的变化。实例证明,方法能够准确评价酸性气田产水气井产能。     

Electronic structures and infrared spectra of C120O2, C120OS and C120S2

Electronic structures and infrared spectra of C₁₂₀XY molecules (X, Y=O, S) and some of the corresponding ions are investigated using PM3 semi-empirical molecular orbital calculations with full optimization of geometrical structures. It is found that the energy penalty is about 30–42 kJ/mol due to introducing a double bond in the fivemembered ring except for C₁₂₀O₂ ⁻ and triplet C₁₂₀O₂ ²⁻. It is also found that the structures of neutral molecules and the corresponding ions are almost the same; for instance, the change of bond length is less than 0.001 nm. The change of frontier orbits from oxide to sulfide is little as well. The triplet states of C₁₂₀O₂ ²⁻ and C₁₂₀OS²⁻ are more stable than their singlet states, which means that C₁₂₀O₂ ²⁻ and C₁₂₀OS²⁻ follow the Hund’s rule. The vibration analysis showed that the infrared spectra of neutral C₁₂₀O₂ and C₁₂₀OS molecules are in good agreement with the experimental results. Compared with the neutral molecule, vibration frequencies of triplet C₁₂₀O₂ ²⁻ change little, but the vibration intensities are enhanced obviously.