固相微萃取-标准加入法检测空气中的苯系物

采用多组分苯系物标准气体进行了固相微萃取技术应用于空气中苯系物检测的研究.分别进行了萃取头、吸附时间的优化实验,针对多种物质存在的竞争吸附效应采用标准加入法进行定量,方法的相对标准偏差在1.8%～8.1%之间,检出限在0.01～0.07 mg/m3之间.     

反相高效液相色谱法同时测定化妆品中的9种糖皮质激素

建立了化妆品中9种糖皮质激素的反相高效液相(RP-HPLC)测定方法.采用酸化甲醇振荡提取,HLB固相萃取小柱净化,HPLC分离测定.在定量范围内均呈良好的线性关系(r≥0.999);回收率为85.0%～99.5%,相对标准偏差小于5.8%,检出限(LOD) (S/N≥3)为1.0 ng,定量限(LOQ) (S/N≥10)为2.0 ng.该法可用于化妆品中泼尼松龙、氢化可的松、可的松、甲基强的松龙、地塞米松、氟米松、倍氯米松、曲安奈德和氟轻松的检测.     

基于顺丁烯二酸和N,N螯合配体构筑的两个新型三维氢键型超分子体系: 结构、磁性质与理论化学研究

通过调变辅助配体,设计合成了两个新的Cu(II)化合物Cu(mal)(tap)(H2O)]n(1) 和 [Cu2(mal)2(bpym)2(H2O)2]·2H2O(2) (其中H2mal =顺丁烯二酸, tap=1,4,5,8-四氮杂菲,bpym=2,2′-联嘧啶),并用X-射线单晶衍射技术对其进行了结构表征。化合物1是一维弓背状配位聚合链通过氢键和π–π 堆积作用拓展形成的三维超分子体系;化合物2 展现一个具有六连接α-Po(46)拓扑的3D→3D二重穿插结构。此外根据晶体结构,利用Gaussian 03W中的DFT方法对化合物1和2进行几何构型优化,同时,用DFT-BS方法研究了两个化合物的磁性,结果表明计算结果与实验结果吻合,它们均具有弱的反铁磁相互作用。     

分散支撑液膜中金属镍(Ⅱ)的迁移研究

研究了以聚偏氟乙烯膜(PVDF)为支撑体,煤油为膜溶剂,有机膦酸为流动载体的分散支撑液膜(DSLM)中金属Ni(Ⅱ)的传输行为;考察了载体种类、料液相pH、Ni(Ⅱ)起始浓度、分散相中H2SO4浓度以及膜溶液与H2SO4溶液体积比对Ni(Ⅱ)传输的影响,并对该体系富集、传输Ni(Ⅱ)的最佳条件进行了讨论;从界面化学和扩散传质角度提出了Ni(Ⅱ)在DSLM中传质动力学方程,采用直线斜率法对扩散层厚度以及金属离子在膜内的扩散系数进行了计算.     

致癌性多环芳烃萘、蒽、芘的分析方法比较

利用薄层色谱（TLC）、紫外光谱（UV）、反相高效液相色谱（RPHPLC）对多环芳烃（PAHs）萘、蒽、芘的分析方法进行了研究。TLC中使用环己烷：氯仿（5：4,V／V）作为展开剂时,三者的R,值分别为0．78、0．65和0．72;用UV法在溶液中测定了三者的最大吸收波长分别为303、380、338nm;当流动相为甲醇：水（9：1,V／V）时三者在RP—HPLC中的保留时间为4．179、5．190、6．178min,5次重复RSD分别为1．1％、1．8％、0．91％,并用于实际水样中萘、蒽、芘的分析。     

Effect of annealing on structural and optical properties of lead tungstate microcrystals

Shuttle-like lead tungstate (PbWO₄) microcrystals are synthesized at room temperature using the precipitation method with the cetyltrimethyl ammonium bromide. Results from both the X-ray diffraction and the scanning electron microscopy show that the lattice distortions of the PbWO₄ microcrystals are reduced significantly when the annealing temperature is increased to 873 K. The result from the ultraviolet-visible diffuse reflectance spectroscopy shows that the exciton absorption appears in the sample annealed at 673 K. The self-trapped exciton luminescence due to the Jahn-Teller effect is also observed in the blue band. The interstitial oxygen ions in the WO₄^2- groups are mainly resposible for the enhancement effect of the green luminescence of the annealed samples. The above results are supported by the spectrum analysis of the as-grown and the post-annealed samples using the X-ray photoelectron spectroscopy.     

光子晶体微纳传感技术的理论与实验研究进展

光子晶体(PC)微纳传感器具有体积小、易集成、响应时间快、控光能力强、可实现无标签检测以及设计灵活等优点,在工业生产、海洋探测、生物医疗检测及环境监测等领域展现出巨大的应用前景。针对基于一维纳米束PC与二维平板PC的微纳光子传感技术,从传感器结构设计和传感性能提升方面,分析了当前国内外PC微纳传感的关键理论和实验技术进展,并通过对比分析,探讨了PC微纳传感技术在未来应用中所面临的挑战及未来发展的趋势。     

A new ellipse fitting method of the minimum differential-mode noise in the atom interference gravimeter

Ellipse fitting is a useful tool to obtain the differential signal of two atom interference gravimeters. The quality standard of ellipse fitting should be the deviation between the true phase and the fitting phase of the interference fringe. In this paper, we present a new algorithm to fit the ellipse. The algorithm is to minimize the differential noise of two interference gravimeters and obtain a more accurate value of the gravity gradient. We have theoretically derived the expression of the differential-mode noise and implemented the ellipse fitting in the program. This new algorithm is also compared with the classical methods.     

Nanoforest-like CdS/TiO_2 heterostructure composites:Synthesis and photoelectrochemical application

In this study, TiO_2 nanoforest films consisting of nanotubes have been synthesized by a simple hydrothermal method and a subsequent sintering technique. The hydrothermal reaction time is important for the controlling of the nanotube diameter and the specific surface area of holistic TiO_2 films. When the hydrothermal process reaction time is up to 8 hours,the diameter of the nanotube is about 10 nm, and the specific surface area of TiO_2 nanoforest films reaches the maximum.CdS nanoparticles are synthesized on TiO_2 nanoforest films by the successive ionic layer adsorption and reaction(SILAR)technique. The transmission electron microscope(TEM) and energy dispersive x-ray spectroscopy(EDX) mapping results verify that TiO_2/CdS heterostructures are realized. A significant red-shift of the absorption edge from 380 nm to 540 nm can be observed after the pure TiO_2 film is sensitized by CdS nanoparticles. Under irradiation of light, the current density of the optimal TiO_2/CdS photoanode is 2.30 mA·cm-2 at 0 V relative to the saturated calomel electrode(SCE), which is 6 times stronger than that of the pure TiO_2 photoanode. This study suggests that the TiO_2 nanoforest consisting of interlinked pony-size nanotubes is a promising nanostructure for photoelectrochemical.     

一种基于模态域波束形成的水平阵被动目标深度估计

水面水下目标分辨与识别一直是被动声呐探测领域的难题.利用一种水平阵模态域波束形成算法获得己知方位目标声源的各阶模态强度,将其与不同深度的各阶参考模态强度进行匹配,最终实现了对声源的深度估计.仿真结果表明,该算法可以在信噪比为-10 dB的情况下,用300Hz带宽的信号样本,实现对声源深度的有效估计.系统分析了不同参数和不同波导条件对该方法目标深度估计性能的影响.其中,阵元数越多,模态样本数越多,计算频段越宽,方位估计精度越高,有效阵长越长,深度估计的性能越好.阵元间距和波导深度的变化不会影响该方法的深度估计性能,并且该方法的深度估计性能在声速剖面、海底参数等波导条件存在扰动时具有鲁棒性.