乌鲁木齐市采暖期大气PM10及PM2.5中Cd的形态分析

2009年12月14日—28日采集了新疆农业大学校园PM10和PM2.5样品,分析了重金属Cd的形态和风险指数。该采样点在冬季采暖期间PM10及PM2.5污染非常严重,PM10和PM2.5中Cd的含量分别为3.642和1.964ng.m-3,均以残渣态为主,但PM2.5中Cd的生物有效性高于PM10中Cd的生物有效性。PM10中Cd的致癌风险为6.56×10-6,而PM2.5中Cd的致癌风险为3.46×10-6,均处于可接受的风险水平。     

用EDXRF法对新疆和田玉进行元素分析

本文利用能量色散X射线荧光分析(Energy dispersive x-ray fluorescence:EDXRF)方法对产于和田的三种常见玉料进行了无损定性、半定量元素分析.结果表明,三种和田玉样品中都有含量较多的Mg,Ca,Si,O等元素以及微量的Al,K,Mn,S,Zn,Fe,Cu等元素.其中样品质量高、油脂性好的白玉和羊脂玉所包含的碳元素浓度较高,分别为24.545%和54.216%,而青玉中没有检测到碳元素.因此和田玉中碳元素的含量也许可以成为鉴别和田玉产品质量的一个标志性参数,对确定软玉的种类具有较好的参考意义.     

Gas chromatography/mass spectrometry determination of amphetamine-related drugs and ephedrines in plasma, urine and hair samples after derivatization with 2,2,2-trichloroethyl chloroformate

A new analytical approach, based on derivatization with 2,2,2-trichloroethyl chloroformate and gas chromatography/mass spectrometry (GC/MS), was investigated for qualitative and quantitative analyses of a large range of amphetamine-related drugs and ephedrines in plasma, urine and hair samples. Sample preparation involved alkaline extraction of analytes from biological samples using Extrelut columns, after addition of the internal standard 3,4-methylenedioxypropylamphetamine (MDPA), and subsequent derivatization to produce 2,2,2-trichloroethylcarbamates. GC/MS analyses, in splitless mode using a slightly polar 30-m capillary column, were performed with quadrupole or ion trap instruments. MS acquisition modes were electron ionization (EI) in full-scan or selected ion monitoring (SIM) modes (quadrupole), and full-scan MS or MS/MS modes with chemical ionization (CI) conditions (ion trap). EI spectra of 2,2,2-trichloroethylcarbamates showed variably abundant molecular ions as well as abundant diagnostic fragment ions, both characterized by ion clusters reflecting the isotope distribution of three chlorine atoms in the derivatized molecules. CI spectra showed abundant protonated molecules. Quantitative studies using EI SIM conditions gave recoveries in the range 74-89%, linear response over ranges of 10-2000 ng/mL (plasma and urine) and 0.20-20 ng/mg (hair), with corresponding limits of detection in the ranges 2-5 ng/mL and 0.1-0.2 ng/mg. Potential applications (following full method validation) include clinical and forensic toxicology, as well as doping control.     

硫化聚间氨基苯硫酚/淀粉复合材料的制备及其对Hg(Ⅱ)的高效吸附

本文以可再生马铃薯淀粉(PS)为原料,通过巯基偶联剂修饰,获得巯基功能化淀粉(PS-SH);然后,间氨基苯硫酚在过硫酸铵作为引发剂的作用下发生聚合反应,得到聚间氨基苯硫酚(PMAT);接着,以单质硫为交联剂,获得硫化聚间氨基苯硫酚/淀粉复合物(PS-S-PMAT),最后对材料的化学组成、结构、形貌进行表征同时探究了各种...     

具有各向异性的两个平行圆柱形介质波导耦合模的研究

研究了具有各向异性两个平行圆柱形介质波导构造的耦合器耦合模特性,采用特异摄动法的耦合模理论推导了耦合模方程.利用固有值和固有矢量的方法解出了耦合模方程,并对其进行理论性分析.分析推导表明,具有微弱旋转效应的两个平行圆形介质波导中除了存在波导间的方向性耦合以外,同时在各波导中还存在互相垂直偏振波模之间的耦合,且其耦合的强度与波导间无旋转效应的偏振独立耦合系数、具有偏振作用的波导间无旋转效应的偏振独立耦合系数的修正值和旋转介电常数存在时被隔离波导中的两个正交模的耦合系数有关.     

微弱旋转效应的圆柱形介质光波导耦合器的研究

具有微弱旋转效应的两个平行圆柱形介质波导的微弱耦合是在矢量波动方程的基础上使用特异摄动法来解析的．对应于复合两个平行圆柱形介质波导系统的耦合模方程是满足麦克斯韦方程和边界条件的情况下得到的,此时摄动阶数限定在一阶范围内．可以发现具有微弱旋转效应的在两个平行波导的弱导内分别独立产生方向性耦合和偏振波的变换．方向性耦合是由耦合系数κ来控制,偏振波的变换是由耦合系数κx来控制．