血橙中微量元素的测定

采用电感耦合等离子体原子发射光谱仪(ICP-AES),对血橙果肉汁、皮、籽中10种微量元素进行了测定。结果表明,血橙果肉汁、皮、籽中含有Ca、Mg、Fe、Zn、Mn、Cu、Ni等丰富的人体必需微量元素,且血橙果皮、籽中的微量元素含量普遍高于果肉汁中的微量元素的含量,这为血橙药效功能的进一步研究和资源综合开发利用提供一定的科学依据。     

Density functional investigations for geometric and electronic properties of In4M and In12M （M = C,Si, In） clusters

First-principle calculations are performed to study geometric and electronic properties of both neutral and anionic In4M and In12M （M = C, Si, In） clusters. In4C and In4Si are found to be tetrahedral molecules. The icosahedral structure is found to be unfavourable for In12M. The most stable structure for In12C is a distorted buckled biplanar structure while for In12Si it is of an In-cage with the Si located in the centre. Charge effect on the structure of In12M is discussed. In4C has a significantly large binding energy and an energy gap between the highest-occupied molecularorbital level and the lowest unoccupied molecular-orbital level, a low electron affinity, and a high ionization potential, which are the characters of a magic cluster, enriching the family of doped-group-IIIA metal clusters for cluster-assembled materials.     

第一性原理研究硫化镉高压相变及其电子结构与弹性性质

采用第一性原理研究了CdS的六方纤锌矿(WZ), 立方闪锌矿(ZB) 和岩盐矿(RS)相在高压条件下的相稳定性、 相变点、电子结构以及弹性性能.WZ相与RS 相可以在相应的压强范围内稳定存在, 而ZB相不能稳定存在.压强大于2.18 GPa时, WZ相向RS相发生金属化相变.WZ相中S原子电负性大于Cd, 且电负性差值小于1.7, CdS的WZ相为共价晶体.高压作用下, S原子半径被强烈压缩, 有效核电荷增加, 对层外电子吸引能力提高, 电负性急剧增大, 导致S与Cd的电负性差值大于1.7, CdS的RS相以离子晶体存在. WZ相的C₄₄随压强增加呈下降趋势, 导致WZ相力学不稳定, 并向RS相转变.当压强大于2.18 GPa时, RS相C₁₁, C₁₂随压强增加而增大, 并且C₄₄保持稳定, 说明RS相具有良好的高压稳定性与力学性能. 关键词： 第一性原理 相变 电子结构 弹性性质     

带量子位相的谐振子及其表示

说明带量子位相的谐振子可以为场的量子化提供一条新的途径,重点研究这种谐振子的数学特性,即它的表示理论.讨论它的Fock空间表示(它是有限维的)和相干态表示,定义了统计学特性完全不同的两类相干态. 关键词：     

在离子液体中利用Perkin反应合成肉桂酸

肉桂酸(3-苯基-2-丙烯酸)是一种重要的有机化工原料和中间体,广泛应用于医药工业、香料工业和其它精细化工等领域。本研究用离子液体作溶剂,无水碳酸钾为碱催化剂,用Perkin法[1-4]合成了肉桂酸,产率最高可达80·8%。1实验部分1.1离子液体的合成离子液体的合成见文献[5],在500mL     

Soliton dynamical properties of Boseben Einstein condensates trapped in a double square well potential

We first present an analytical solution of the single and double solitions of Bose-Einstein condensates trapped in a double square well potential using the multiple-scale method. Then, we show by numerical calculation that a dark soliton can be transmitted through the square well potential. With increasing depth of the square well potential, the amplitude of the dark soliton becomes larger, and the soliton propagates faster. In particular, we treat the collision behaviour of the condensates trapped in either equal or different depths of the double square well potential. If we regard the double square well potential as the output source of the solitons, the collision locations (position and time) between two dark solitons can be controlled by its depth.     

极端条件下6Li2O的热力学性能与电子结构

 采用密度泛函理论与准谐振德拜模型研究了面心立方相的⁶Li₂O在极端条件下的热力学性质与电子结构。结果表明: ⁶Li₂O的热膨胀系数在任何温度下都随压强增加明显降低,但仅当压强较低(低于40 GPa)时,温度对6Li2O的热膨胀系数的影响才明显;O原子半径随压强增大而迅速降低,而随温度的变化并不明显;在低压条件下(低于40 GPa),带隙随温度的升高缓慢降低;而在高压条件下(高于40 GPa),温度对带隙宽度的影响几乎可以忽略;无论在什么温度条件下,带隙宽度均随压强的增大而迅速增加。     

Controlling the collision between two solitons in the condensates by a double-barrier potential

We present an analytical solution of two solitons of Bose-Einstein condensates trapped in a double-barrier potential by using a multiple-scale method.In the linear case,we find that the stable spots of the soliton formation are at the top of the barrier potential and at the region of barrier potential absence.For weak nonlinearity,it is shown that the height of the barrier potential has an important effect on the dark soliton dynamical properties.Especially,in the case of regarding a double-barrier potential as the output source of the solitons,the collision spots between two dark solitons can be controlled by the height of the barrier potential.     

大学物理与大学物理实验课程“三位一体”教学模式的研究与实践

针对目前高校公共基础课程中理论教学与动手实践及科技创新能力培养等方面的结合性不强,公共基础课程的功能和作用未能得到充分发挥,学生科技创新意识淡薄等现状,对大学物理和大学物理实验课程中如何实施“教学、实践、科研”三位一体的教学模式进行了研究和实践.实践表明,该模式可以将长期割裂开来的基础理论的传授、动手能力的培训、科学研究方法和能力的培养三个方面有机地结合起来,充分发挥公共基础课程在“创新型人才”培养中的功能和作用.     

极谱法测定维生素B12中的痕量钴

在pH 10,0.04 mol/L的NH3*H2O-NH4Cl缓冲溶液中,钴-百里香酚酞在NaNO2存在下,于-1.25 V(vs.SCE)产生一尖锐、灵敏的二次导数极谱波,峰电流与钴(Ⅱ)浓度在5.0×10-8～5.0×10-6 mol/L范围内呈线性关系,检出限为2.0×10-8 mol/L.研究了该波的性质,证明该波为吸附波.方法用于维生素B12中痕量钴的测定,结果满意.