顶空液液萃取-气相色谱-质谱法用于白术挥发性成分的分析

采用高温顶空液相萃取再转移的方法,对中药白术中挥发性成分进行萃取分离富集,采用顶空液液萃取/气相色谱-质谱(HS-LP-LPE/GC-MS)联用法进行测定,并与传统水蒸汽蒸馏法(SD)提取的挥发性成分进行对比。对各种测定条件和影响因素进行了考察,最佳萃取条件为:1.0 mL PEG 400为高温萃取剂,样品用量1.2 g,萃取温度120℃,萃取时间60 min,再将萃取剂用1.0 mL正己烷进行反萃取后进行GC-MS分析;采用HS-LP-LPE/GC-MS鉴定了33个组分,占总组分含量93.18%;SD鉴定了31个组分,占总组分含量97.12%。两种方法共同检测到的组分有29个,均以苍术酮(Atractylone)含量最高。结果表明,两种方法所提取的组分基本相同,可用于白术挥发性成分的测定。     

Revealing the Cell Entry Dynamic Mechanism of Single Rabies Virus Particle

The rabies virus is a neurotropic virus that causes fatal diseases in humans and animals. Although studying the interactions between a single rabies virus and the cell membrane is necessary for understanding the pathogenesis, the internalization dynamic mechanism of single rabies virus in living cells remains largely elusive. Here, we utilized a novel force tracing technique based on atomic force microscopy(AFM) to record the process of single viral entry into host cell. We revealed that the force of the rabies virus internalization distributed at (65±25) pN, and the time was identified by two peaks with spacings of (237.2±59.1) and (790.3±134.4) ms with the corresponding speed of 0.12 and 0.04 μm/s, respectively. Our results provide insight into the effects of viral shape during the endocytosis process. This report will be meaningful for understanding the dynamic mechanism of rabies virus early infection.     

论高校体育中"以人为本"教育思想的构建

采用文献资料调研和逻辑分析等方法,讨论了高校体育中"以人为本"教育思想的构建.结果表明,高校体育教学中应从教育教学思想、教学目标、教学内容、教学方法及教学评价等诸方面人手,进行人性化的设计和选择,才能真正实现高校体育教育思想从"以物为本"向"以人为本",从"生物体育观"向"人文体育观"的根本转变.同时更有利于对学生主体性人格的培养.     

多媒体网络教学资源库的视频编码技术研究

详细分析了H．264视频编码特点,将其应用到多媒体网络教学资源库中,有效解决了网络多媒体课件数据量大、传输速度慢等问题,以满足多媒体网络教学的需要．     

Synthesis,Crystal Structure and Photoluminescence of a Three-coordinate Ag(Ⅰ) Complex

A three-coordinate Ag(I) complex, [Ag(Mepzpy)(PAr3)]BF4·H2O(1, Mepzpy = 3-methyl-1-(2-pyridyl)pyrazole, PAr3 = tri(o-tolyl)phosphine), was synthesized from the reaction of Ag(CH3CN)4BF4, PAr3 and Mepzpy in CH3 CN at room temperature. The compound was characterized by UV-vis, NMR and X-ray single-crystal structure analysis. It crystallizes in triclinic space group P1 with a = 10.2251(5), b = 10.6014(5), c = 15.7012(5) , α = 92.963(3), β = 92.641(3), γ = 114.647(4)o, V = 1540.6(1) 3, Z = 2, Mr = 676.24, Dc = 1.458 g/cm3, F(000) = 688, μ = 6.187 mm-1, GOOF = 1.038, the final R = 0.0530 and w R = 0.1493 for 6371 observed reflections with I 2σ(I). Compound 1 is ionic. It is composed of a BF4- anion and a [Ag(Mepzpy)(PAr3)]+ cation. The Ag(I) ion adopts a distorted trigonal pyramidal coordination geometry defined by two nitrogen atoms and a phosphorous atom. The complex emits blue luminescence with maximum peaks at 470 nm in solid state at room temperature.     

高效液相色谱-电喷雾串联质谱法测定畜禽粪便中四环素类抗生素

建立了高效液相色谱-电喷雾串联质谱法(HPLC-MS/MS)测定畜禽粪便中四环素类抗生素的分析方法。样品经甲醇-乙酸-水(体积比6∶3∶1)溶液提取,OASIS HLB小柱净化后,采用Waters Symmetry C18色谱柱(150×3.9mm,5μm)进行分离,以0.3%甲酸水溶液-0.3%甲酸乙腈溶液梯度洗脱,电喷雾正离子模式多反应监测(MRM)模式定量分析。在优化的色谱条件下,四环素、土霉素和金霉素在0.05~1.0mg/L范围内具有良好的线性,其检出限分别为0.025、0.084、0.098mg/kg;样品回收率为80%~103%。实验结果表明,该方法较液相色谱法具有更高的准确性和灵敏度,可满足畜禽粪便中四环素类抗生素残留的检测要求。     

一类高阶非线性Duffing型微分方程周期解的存在与唯一性

考虑一类具有时滞的高阶非线性Duffing型微分方程,利用重合度理论,获得此方程存在唯一周期解的充分条件.     

两表面层铁电薄膜体介质层效应理论研究

基于横场伊辛模型的平均场近似理论,研究了具有两个表面层铁电薄膜的体介质层对整个铁电薄膜相变性质的影响.给出了一个适合于研究任意层数具有两个表面层及体介质层铁电薄膜相变性质的递归公式.研究了体介质层的交换相互作用参量和横场参量对整个铁电薄膜相图的影响,以及交换相互作用参量对横场参量过渡值的影响和横场参量对交换相互作用参量的影响.结果表明,相图中铁电区、薄膜的居里温度、体介质层的横场参量过渡值均随体介质层的交换相互作用参量的增大而增大;体介质层的交换相互作用参量随体介质层的横场参量的增大而增大;而相图中铁电区、薄膜的居里温度却随体介质层的横场参量的增大而减小,并且发现体介质层的交换相互作用参量对薄膜的影响比其横场参量稍大些.最后也给出了两个表面层的交换相互作用对相图的影响.     

应急设计框架:卫星总体方案设计

以卫星有效载荷总体方案变型设计为背景,探讨在人为或自然灾害的非正常情况下的应急设计方法．首先给出应急设计系统定义,然后给出实现应急设计基本依据：一是基于演化算法、Agent、人机结合和协同设计理论;二是仿蚁群社会应急行为．本系统的关键是,构造基干人与演化算法相结合的Agent（human—computer cooperation Agent,HC—Agent）,进而基于混合P2P网络模型构成多HC—Agent的协同设计系统,以使该应急设计系统具有抗干扰、自适应、快速响应的设计能力．     

Investigation on Electronic Structures and Spectra for the Substituted Fullerene C77B-

1 INTRODUCTION After Guo[1] synthesized and detected C60-nBn and C70-nBn by mass spectra, investigations on fullerenes doped by other atoms became more and more interesting. Andreoni[2] studied the impurity states of the doped fullerenes C59B; Dong[3] calculated the structural and electronic properties of C59B; Wang[4] assessed the stability of heterohedral fullerenes C60-xBx. Lamparth[5] prepared C59N and C69N , and put forward the possible structures for C59N . Sahoo[6] obtained…