用于荧光光谱测定的微量固体粉末样品制样优化*

为满足微量固体粉末荧光检测要求,采用薄层制样法,改变黏结剂种类、黏结剂的用量、涂层厚度以及后处理方法来进行其制样工艺优化。 结果表明:以聚乙烯醇做黏结剂、1∶5的固液比、在50 ℃烘干30 min、涂片次数3层的薄层制样优化工艺可满足荧光固体测样的要求。采用t检验比较固体样品池装样和薄层制样法的荧光检测结果发现两者无显著性差异,薄层制样优化工艺的需样量较样品池减少90%。     

一种便携快速测量水中铅和镉含量的仪器-ANDalyze

快速测量污染水中重金属元素含量对于监测野外突发污染至关重要.建立了使用以生物酶（DNA酶）为原理的便捷仪器快速测定污染水中铅（Pb）和镉（Cd）元素含量的方法.使用生物酶传感器对标准溶液进行测量,根据溶液推荐和测量浓度之间的线性关系对仪器进行校准后,可测量的质量浓度范围:Pb为2~100 μg/L,Cd为0.1~1.0 mg/L.仪器可以在3~5 min内方便快速完成重金属的现场测量,使用DNA酶可以快速获得污染水中的微量金属元素含量,有利于野外重金属污染的即时测量.     

Tuning the mechanical properties and degradation properties of polydioxanone isothermal annealing

Polydioxanone (PPDO) is synthesized by ring-opening polymerization of p-dioxanone, using stannous octoate as the catalyst. The polarized optical micrograph (POM) shows thes pherulite growth rate of PPDO decreases with an increase in the isothermal crystallization temperature. PPDO is compression-molded into bars, and PPDO bars are subjected to isothermal annealing at a range of temperatures (Ta = 50, 60, 70, 80, 90, and 100 °C), and correspond to three different annealing times (ta = 1h, 2h, 3h). The effect on PPDO is investigated by using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and scanning electron microscopy (SEM). With an increase in Ta and ta, the grain size and the degree of crystallinity also increase. Meanwhile, the tensile strength is significantly improved. The PPDO bars (90 °C, 2 h) reach the maximum crystallinity (57.21%) and the maximum tensile strength (41.1 MPa). Interestingly, the heat treatment process does not result in serious thermal degradation. It is observed that the hydrolytic degradation of the annealed PPDO is delayed to some extent. Thus, annealed PPDO might have potential applications, particularly in the fields of orthopedic fixation and tissue engineering.     

基于(C-H)+…X-氢键作用的阴离子识别与传感的研究进展

对基于(C—H)+…X-氢键类型的阴离子识别以及识别过程所引起的光化学传感和电化学传感的研究进展进行了评述.     

Electrospray Ionization Mass Spectra of Amino Acid Methyl Ester 5′-Phosphoramidates of 2′,3′-Isopropylideneuridine

Amino acid methyl ester phosphates were synthesized and determined by using positive-ion mode electrospray ionization mass spectrometry(ESIMS) in combination with multistage tandem mass spectrometry. The fragmentation pathways were investigated, and it was observed that most fragment ions contained the phosphoryl group. It was interesting to observe that the fragmentation pathways of the protonated molecule show some differences when compared with those of the sodium ion adduct. The methoxy group of amino acid methyl ester can migrate from the carbonyl group to the phosphoryl group in the sodium ion adduct.     

液体电阻率测量装置的设计与制作

针对液体本身物理性质复杂、电阻率难以测量的问题,本文设计了一种新型液体电阻率测量装置.为有效采集被测对象的信息,对容器结构进行了巧妙设计,创新性地实现了石墨电极与容器一体化,提高了测量精度;利用传感技术采集电压、电流信号并将数据传入单片机,经单片机运算后通过液晶屏实时显示电阻率,具有快捷、准确测量的优点,在教学科研方面有一定实用价值.     

星载海洋激光雷达最佳工作波长分析

星载激光雷达是实现海洋垂直剖面探测的有效工具,也是目前迫切需求的海洋光学遥感手段。对星载海洋激光雷达的波长参数进行评估对保证探测有效性具有重要意义。本文从探测深度和信噪比两方面分析了星载海洋激光雷达探测全球海洋的最佳波长。利用MODIS 10个波段的水体光学特性数据,估算全球海水探测深度及相应的最优波长;并根据太阳夫琅禾费暗线特性,对信号信噪比进行优化。结果表明:在探测深度方面,最优探测波长在488 nm波段的海洋占全球海洋面积的70%左右,并且全球95%以上的海域在488 nm波段的探测深度优于0.8倍的真光层深度;在信噪比方面,相对于488 nm波段,486.134 nm夫琅禾费暗线处采用0.1 nm带宽的滤光片可以将背景光强度降低70%,相应地回波信噪比整体提升了约5.0%。就全球海洋探测来说,使用486.134 nm作为探测波长可以提高探测深度,有效抑制太阳背景光,提高信噪比,因此,486.134 nm是星载海洋激光雷达的最佳工作波长。     

Cu过量对Cu1+x Al1-x O2(0≤x≤0.04)薄膜结构与光电性能的影响

以单相多晶Cu1+x Al1-x O2陶瓷做靶材,采用射频磁控溅射方法在石英衬底上沉积了Cu过量的Cu1+x Al1-x O2(0≤x≤0.04)薄膜.通过X射线衍射(XRD)、紫外吸收光谱以及电导率的测试,表征了不同含Cu量Cu1+x Al1-x O2薄膜的结构与光电性能.结果表明,沉积态薄膜经退火处理后,由非晶转变为具有铜铁矿结构的纯相Cu1+x Al1-x O2;退火态薄膜在可见光区域的平均透过率约为55;,平均可见光透过率不受Cu含量的影响;退火态薄膜样品的室温电导率随Cu含量的增加而增大,Cu1.04 Al0.96 O2的室温电导率最高,为1.22×10-2 S/cm;在近室温区(200～300 K),退火态薄膜均很好地符合Arrhenius热激活模式.