用多极理论计算复杂截面的电缆电导

将多极理论用于复杂截面的电缆电导计算，为电缆电导计算提供一种新的计算方法。实例计算结果表明，多极理论的计算精度比边界元法的计算精度高得多。     

荧光法测定蘑菇及其水解液中痕量硒的研究

采用环己烷萃取，２，３－二氨基萘衍生进行了蘑菇及其水解液中痕量硒的荧光法测定。对影响其荧光测量的各种因素进行了较为详细的研究。实验表明，该法线性范围宽（４～５μｇ／Ｌ）、检出限低（２μｇ／Ｌ）、稳定性好、回收率在９１４％～１０２２％之间，相对标准偏差＜２６％。     

同位素稀释高分辨气相色谱-高分辨质谱法检测烟道气中的低氯代二恶英

建立了同位素稀释高分辨气相色谱-高分辨质谱检测烟道气中痕量低氯代二恶英的分析方法。采用索氏提取富集烟道气样品中的目标物,提取液经过复合硅胶柱和碱性氧化铝柱净化后,进行高分辨气相色谱-高分辨质谱检测。采用DB-5MS毛细管色谱柱（30 m×0.25 mm×0.25 μm）分离,以保留时间和同位素特征离子丰度比定性,以与同位素的峰面积比值定量。实验结果表明,方法的回收率为66.6%~112.5%,相对标准偏差（RSD）的范围为19.9%~40.5%（n=5）,方法的检出限（LOD）为0.027~0.485 μg/L。应用该方法检测了3个焚烧炉烟道气样品,回收率在85.7%~137.0%范围内,样品中目标物含量分布在11.4~9183 pg/Nm³之间。结果表明该方法适合用于烟道气中痕量低氯代二恶英的检测。     

多足开链化合物与阴离子的相互作用

设计合成了６种萘取代的脲及硫脲类多足开链化合物，利用吸收光谱、荧光光谱及_１Ｈ ＮＭＲ波谱手段详细研究了该类化合物作为主体分子与不同种类的阴离子客体分子间的相互作用．实验表明，客体阴离子Ｈ_２ＰＯ_４~－及ＨＳＯ_４~－可以与三足的脲及硫脲主体分子形成主客体配合物从而诱导主体分子光物理性质发生变化，而且表现出较好的选择性．测定了主客体配合物的稳定常数和化学配位比，对三足脲和硫脲与阴离子客体的选择性和识别作用进行了比较，提出了相应主客体配合物可能的配位方式和结构形式．     

核磁共振实验原理及数据分析

从量子角度阐明了核磁共振的基本原理,测定了水和聚四氟乙烯的核磁共振频率,计算了对应样品的旋磁比。     

基于模拟方法生成血管树的人舌三维温度场数值模拟

采用分步模拟方法生成血管树并以此作为物理模型,进行舌体三维温度场的实验研究与数值计算。计算分为舌体组织和血液温度场数值模拟两部分,相应数学模型也包括舌体组织控制方程、血液控制方程及两者之间的耦合方程。在考虑了血液与组织间的耦合换热,舌津液蒸发的影响基础上,采用数值模拟得到的舌面对流换热系数,使计算结果与红外热像验证极为近似。以模拟方法生成的血管树替代生物体的血管铸型,在某种意义上说将生物体三维传热计算方法的研究推向了一个新的层面。     

Non-Axisymmetric Oscillation of Acoustically Levitated Water Drops at Specific Frequencies

A category of non-axisymmetric oscillations of acoustically levitated water drops was observed. These oscillations can be qualitatively described by superposing a sectorial oscillating term upon the initial oblate shape resulting from the effect of acoustic radiation pressure. The oscillation frequencies are around 25 Hz for the 2-lobed mode and exactly 50 Hz for the 3- and 4-1obed modes. These oscillations were excited by the disturbance from the power supply. For the same water drop, higher mode oscillations were observed with more oblate initial shape, indicating that the eigenfrequencies of these non-axisymmetric oscillations decrease with increasing initial distortion. The maximum velocity and acceleration within the oscillating drop can attain 0.3 m·s^-1 and 98.7 m·s^-2 respectively, resulting in strong fluid convection and enhanced heat and mass transfer.     

Effects of Contact Atomic Structure on Electronic Transport in Molecular Junction

Based on nonequilibrium Green＇s function and first-principles calculations, we investigate the change in molecular conductance caused by different adsorption sites with the presence of additional Au atom around the metal- molecule contact in the system that benzene sandwiched between two Au（111） leads. The motivation is the variable situations that may arise in break junction experiments. Numerical results show that the enhancement of conductance induced by the presence of additional Au is dependent on the adsorption sites of anchoring atom. When molecule is located on top site with the presence of additional Au atoms, it can increase molecular conductance remarkably and present negative differential resistance under applied bias which cannot be found in bridge and hollow sites. Furthermore, the effects of different distance between additional Au and sulfur atoms in these three adsorption sites are also discussed.