实时直接分析-高分辨质谱法快速检测化妆品中的氯霉素

建立了一种用于化妆品中氯霉素快速检测的实时直接分析-高分辨质谱法。样品以乙醇为提取溶剂超声、振荡萃取,纯水稀释1倍后,采用12 Dip-it Samplers模式进样,在负离子模式下,以全扫描-平行反应监测(Full MS-PRM)模式进行直接定量分析。离子化温度为500 ℃,进样速度为0.3 mm/s。结果表明,氯霉素在0～100 mg/L范围内具有良好的线性关系,相关系数(r)为0.998　4,方法定量下限(LOQ)为3.0 mg/kg。在3.0、6.0、30 mg/kg 3个加标水平下的回收率为70.2%～119%,相对标准偏差(RSD)为8.4%～17%。该方法具有样品前处理简单、分析速度快、基质干扰小等优点,适用于化妆品中氯霉素的快速检测。     

Passive Q-Switching Modelocked Yb^3＋ -Doped Fibre Laser with GaAs Absorber Grown at Low Temperature

GaAs absorber was grown at low temperature (550℃) by metal organic chemical vapour deposition (MOCVD)and was used as an output coupler with which we realized Q-switching modelocked yb^3 -doped fibre laser. The shortest period of the envelope of the Q-switched modelocking is about 31μs. The modelocking threshold is 4.27 W and the highest average output pulse power is 290mW. The modelocking frequency is 12 MHz.     

基于液晶光阀的防眩目眼镜

基于常开型液晶光阀的电光特性设计了一种司机夜间行车时佩戴的液晶眼镜．液晶眼镜能够主动根据外界光强变化改变自身的透射率,从而使透射光强趋于稳定值．实验结果表明液晶眼镜能有效防止对面车灯引起的眩目, 同时不影响司机对路面的观察．     

平行双导线的无线电漏泄

漏泄传输技术是近代科技解决无线电波在地下通信的有效途径.针对无线电波地下传输的困难,对比漏泄同轴电缆,从理论和实验分析了平行双导线在中频段的无线电漏泄,并对平行双导线的应用前景做了展望.     

刚果红分光光度法测定血清蛋白质

1　引　　言蛋白质的定量测定在生物化学、药学及食品等学科中有重要意义 ,也是临床诊断疾病及检查治疗效果不可缺少的分析项目。蛋白质含量测定方法很多 ,目前研究最多、应用最广的为染料结合法 ,但未见有刚果红作显色剂测定蛋白质的报道。研究了刚果红与蛋白质反应的基本条件 ,建立了以刚果红测定蛋白质的分光光度分析法 ,用于实际人血清样品中总蛋白质的测定 ,取得了满意的结果。与经典的考马斯亮蓝法比较 ,本法简便灵敏 ,稳定性好 ,线性范围较宽 ,颇有实用意义。2　实验部分2 .1　主要仪器及试剂　Ｌａｍｂｄａ 3 5紫外 可见分光光度计 …     

气体中蒸发法制备InSb纳米颗粒

用气体中蒸发的方法在蓝宝石基片上制备了纳米InSb颗粒膜．通过透射电镜分析显示，该方法可以制得多晶的InSb纳米颗粒，且颗粒均匀地分布在蓝宝石基片表面上；用X射线能谱仪分析样品得到两种元素的百分比接近1：1．实验结果表明，通过改变设备的工作条件，可以得到具有不同颗粒尺寸的InSb纳米颗粒．     

催化动力学分析法测定超微量铋的研究

一、概述文献中关于铋的动力学分析法的报导,仅见二则。一是利用Bi~(8+)对H_2O_2-发光精反应的催化作用;一是利用Bi~(8+)对伞形花酮的磷酸酯被碱性磷酸酯酶裂解为强荧光性伞形花酮的抑制作用。前者选择性较差,Co、Fe、Mn、Mo、Cu、Hg、Os严重干扰;后者选择性高(仅Be有抑制作用),但所用试剂特殊且昂贵,不易推广。     

单根聚苯胺纳米线导电性的研究

纳米线(管)的模板合成和导电原子力显微镜(C-AFM)结合是一种近期发展起来研究单根一维纳米结构及阵列导电性的有效方法. 本文利用C-AFM测量了阳极氧化铝(AAO)模板电化学合成制备的单根聚苯胺纳米线的电导率, 研究了直径、氧化还原态对单根聚苯胺纳米线电导率的影响. 从I－V曲线可以看到, 其导电性质与半导体类似，但又不同于半导体． 尚未观察到反向击穿现象，可能原因是, 在一定的反向偏压下的离子脱嵌使得它由部分氧化态（导电态）转变为还原态（绝缘态）；电导率随纳米线直径减小而线性地增加；以ClO₄^－离子掺杂的氧化态和还原态比部分氧化态的电导率低二个数量级.     

Sniffing lung cancer related biomarkers using an oxidized graphene SAW sensor

Decane is one of the volatile organic compounds (VOCs) in human breath. Successful detection of decane in human breath has vast prospects for early lung cancer diagnosis. In this paper, a novel detecting device based on a filter surface acoustic wave (SAW) gas sensor is presented. SAW sensors coated with a thin oxidized graphene film were used to detect decane in parts per million (ppm) concentrations. Control and signal detection circuits were designed using a vector network analyzer with a detection resolution of insertion loss down to 0.0001 dB. The results showed that the SAW sensor could respond quickly with great sensitivity when exposed to 0.2 ppm decane. This device shows tremendous potential in medical diagnosis and environmental assessment.     

Quantum confinement effect in <Emphasis Type="Italic">β</Emphasis>-SiC nanowires

The quantum confinement effect is important in nanoelectronics and optoelectronics applications; however, there is a discrepancy between the theory of quantum confinement, which indicates that band-gap widening occurs only at small sizes, and experimental observations of band-gap widening in large-diameter nanowires (NWs). This paper reports an obvious blue shift of the absorption edge in the UV-visible absorption spectra of SiC NWs with diameters of 50–300 nm. On the basis of quantum confinement theory and high-resolution transmission electron microscopy images of SiC NWs, band-gap widening in SiC NWs with diameters of up to hundreds of nanometers is fully explained; the results could help to explain similar band-gap widening in other NWs with large diameters.