三甲氧基苄啶分子印迹整体柱的制备及色谱性能

选择甲基丙烯酸为功能单体\, 甲基丙烯酸乙二醇双酯为交联剂, 制备了三甲氧基苄啶分子印迹整体柱, 对整体柱材料的形貌进行了表征, 并且研究了TMP和5种磺胺类药物在分子印迹整体柱上的色谱行为.     

中国农村居民省际间消费结构差异分析

近年来我国农村居民恩格尔系数下降迅速,反映了农村居民的生活水平和生活质量得到了一定的改善。但农村居民恩格尔系数在省际间出现东部高而中西部低的反常现象让人难以理解。本文借助经济计量方法建立农村居民恩格尔系数的Panel Data模型,定量分析了农村居民收入水平、教育收费和粮食价格对各省农村居民恩格尔系数影响的程度,得出教育收费对食品支出的挤占效应是导致农村居民恩格尔系数反常变化的主要原因。     

数学建模课程的教学与综合素质教育

本结合教学模型课的教学和竞赛的体会,探讨丁综合性大学对大学生综合素质培养的思路和方法．认为教改的目的在于解决“面向”、“需求”和“服务”的问题．综合素养质是评价教改的准则,课程建设是综台素质教育的核心和动力,教学内容、教学方法、教学手段的更新及参加竞赛是素质培养教育的良好途径和重要环节。     

数学建模课程的教学与综合素质教育

本文结合教学模型课的教学和竞赛的体会,探讨了综合性大学对大学生综合素质培养的思路和方法。认为教改的目的在于解决“面向”、“需求”和“服务”的问题。综合素质是评价教改的准则,课程建设是综合素质教育的核心和动力,教学内容、教学方法、教学手段的更新及参加竞赛是素质培养教育的良好途径和重要环节。     

关于拟弱几乎周期点的一些结论和公开问题(英文)

本文主要在离散动力系统中,概括了有关于拟弱几乎周期点的一些结论并提出了一些公开问题.     

Decomposition of the Two Lowest Lamb modes in a Bonded Plate

Based on the expression of the dispersion equation of Lame waves in an adhesive two-layered plate pressented in our proevious paper [Chin,Phys,Lett,18(2001)1483],the two lowest Lamb modes,the symmetric mode S0 and the antisymmetric mode A0 are successfully decomposed in the low-frequency regime,Relations between the rigidity of the bond and the velocity of the two Lamb modes are found,which lay a foundation for the estimation of the bond rigidity of the adhesive plate.The influence of the variations of the bond rigidity in terms of the stiffness constants KN and KT of the spring model on the velocity of the two Lamb modes in discussed and numerically evaluated.numerical results indicate that the deterioration of the bond rigidity causes the phase velocity decrease for Lamb modes of the two lowest order,thus having a possibility for the evaluation of the bonding state of the adhesive plate by using ultrasonic wave velocity measurement.     

Co100-xMnx合金在GaAs(001)表面的生长结构和磁性的实验研究

对Co_100-xMn_x合金在GaAs(001)表面的分子束外延生长、晶体结构和磁学性质进行了研究.结果表明,当0100-xMn_x合金薄膜是体材料中不存在的体心立方(bcc)结构,并且具有较强的铁磁性,当44100-xMn_x合金薄膜最初为bcc结构,随着厚度的增加,逐渐从bcc向面心立方(fcc)结构转化,最后成为完全的fcc结构,薄膜具有较 关键词：     

Theoretical Study on Inner Shell Electron Impact Excitation of Lithium

Cross sections for electron impact excitation of lithium from the ground state 1s^22s to the excited states 1s2s^2, 1s2p^2, 1s2snp （n = 2-5）, 1s2sns （n = 3 5）, 1s2pns （n = 3-5）, and 1s2pnp （n = 3-5） are calculated by using a full relativistic distorted wave method. The latest experimental electron energy loss spectra for inner-shell electron excitations of lithium at a given incident electron energy of 2500 eV [Chin. Phys. Lett. 25 （2008）3649] have been reproduced by the present theoretical investigation excellently. At the same time, the structures of electron energy loss spectra of lithium at low incident electron energy are also predicted theoretically, it is found that the electron energy loss spectra in the energy region of 55-57eV show two-peak structures.     

半波长超导共面波导谐振腔传输及温度特性研究

超导共面波导谐振腔主要包括四分之一波长型和半波长型.本文对半波长超导共面波导谐振腔使用并联RLC电路进行等效分析,使用sonnet软件进行仿真其传输特性,通过电子束蒸发和激光直写等工艺制备出样品,在低温超导状态下使用矢量网络分析仪对其传输特性进行测量,以及通过持续降温方式研究其传输特性受温度的影响.实验表明:测得的谐振频率和外部品质因数与设计值吻合;谐振频率受动态电感的影响随温度降低而升高;外部品质因数随温度降低而保持基本不变;内部品质因先受导体损耗的影响随温度降低而急剧升高,当温度降低至一定温度后内部品质因数受介电损耗的影响随温度降低而保持基本不变;总品质因数在温度较高时主要来自于导体损耗,在温度较低时主要来自于介电损耗和外部品质因数,随温度的变化趋势和内部品质因数一致.     

Structural and physical properties of BiFeO3 thin films epitaxially grown on SrTiO3（001） and polar（111） surfaces

The influence of surface polarity on the structural properties of BiFeO3 （BFO） thin films is investigated. BFO thin films are epitaxially grown on SrTiO3 （STO） （100） and polar （111） surfaces by oxygen plasma-assisted molecular beam epitaxy. It is shown that the crystal structure, surface morphology, and defect states of BFO films grown on STO substrates with nonpolar （001） or polar （111） surfaces perform very differently. BFO/STO （001）is a fully strained tetragonal phase with orientation relationship （001）[100]BFOII（001）[100]STO, while BFO/STO （111） is a rhombohedral phase. BFO/STO （111） has rougher surface morphology and less defect states, which results in reduced leakage current and lower dielectric loss. Moreover, BFO films on both STO （001） and STO （111） are direct band oxides with similar band gaps of 2.65 eV and 2.67 eV, respectively.