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981.
Dubravka Jembrih Manfred Schreiner Momtchil Peev Peter Krejsa Christian Clausen 《Mikrochimica acta》2000,133(1-4):151-157
Art Nouveau (Tiffany, Loetz) and modern (Jack Ink, Strini Art Glass) iridescent glass fragments were characterized using
energy dispersive X-ray fluorescence analysis (EDXRF) and energy dispersive X-ray microanalysis in a scanning electron microscope
(SEM/EDX) in combination with factor analysis in order to obtain clustring. A character istic of Tiffany glass fragments is
leaded bulk glass, whereas in the case of Loetz K-Ca-Si bulk glass could be determined. Modern glass fragments show a high
amount of Na (7 wt% in the bulk of Jack Ink) and 0.6–1.5 wt% Sr in the bulk of Strini Art Glass. The contents of Si and Ca
are similar to Loetz glass. Furthermore, the differences in the structure of the glass artifacts could be determined. The
cross-sections of Tiffany show a layered structure of the bulk without a specific surface layer whereas the cross-sections
of Loetz glass reveal a homogeneous bulk material with one or two homogeneous surface layers in the BE-image. In the case
of the Jack Ink a homogeneous bulk glass and an inhomogeneous multilayered surface could be determined. Strini Art Glass show
a homogeneous bulk glass and a homogeneous surface layer in the backscattered electron image. 相似文献
982.
量子化电磁场在色散吸收有限介质中的传播 总被引:8,自引:3,他引:5
通过量子化吸收和色散介质中的电磁场,研究线极化波垂直入射至吸收和色散介质界面处的反射和折射行为,给出介质界面处光的正则量子理论. 相似文献
983.
984.
By means of variable separation approach, quite a general excitation of the new (2 + 1)-dimensional long dispersive wave system: λqt + qxx - 2q ∫ (qr)xdy = 0, λrt - rxx + 2r ∫(qr)xdy = 0, is derived. Some types of the usual localized excitations such as dromions, lumps, rings, and oscillating soliton excitations can be easily constructed by selecting the arbitrary functions appropriately. Besides these usual localized structures, some new localized excitations like fractal-dromion, farctal-lump, and multi-peakon excitations of this new system are found by selecting appropriate functions. 相似文献
985.
Interaction between compacton and anticompacton,peakon and antipeakon in (2 + 1)-dimensional spaces 总被引:2,自引:0,他引:2
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Starting from the variable separation solution obtained by using the extended homogenous balance method, a class of novel localized coherent structures such as the multi-peakon-antipeakons solution and the multi-compacton-anticompactons solution of the (2+1)-dimensional dispersive long wave equation are found by selecting appropriate functions. These new structures exhibit some novel interaction features that are different from one of the known results. Their interaction behaviour is very similar to the completely elastic collisions between two classical particles. 相似文献
986.
The pulse with a rectangular envelop propagating through
the caesium vapour with two gain lines used in the Wang, Kuzmich, and Dogariu
[Nature (London) 406 (2000) 277] experiment is studied. It is shown
that there exists an obvious distortion for the pulse. 相似文献
987.
New multi—soliton solutions and travelling wave solutions of the dispersive long—wave equations 总被引:7,自引:0,他引:7
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Using the extended homogeneous balance method,the (1 1)-dimensional dispersive long-wave equations have been solved.Starting from the homogeneous balance method,we have obtained a nonlinear transformation for simplifying a dispersive long-wave equation into a linear partial differential equation.Usually,we can obtain only a type of soliton-like solution.In this paper,we have further found some new multi-soliton solutions and exact travelling solutions of the dispersive long-wave equations from the linear partial equation. 相似文献
988.
989.
食用菌中多菌灵残留的分散固相萃取/高效液相色谱法测定 总被引:3,自引:0,他引:3
建立了食用菌中多菌灵残留量的测定方法.采用乙腈提取样品,提取液经十八烷基硅烷(ODS)和乙二胺-N-丙基硅烷(PSA)吸附净化后,采用反相高效液相色谱-紫外可见检测器进行测定,外标法定量.色谱条件:色谱柱为Agilent Eclipse XDB C18柱(4.6 mm×150 mm,5 μm,i.d.),流动相为甲醇-0.02 mol/L磷酸盐缓冲溶液(pH 7.4)(体积比25 ∶ 75),流速1 mL/min,柱温30 ℃,检测波长282 nm.结果表明,多菌灵在0.05 ~10 mg/L质量浓度范围内线性良好,相关系数为0.999 9;方法的相对标准偏差(RSD)不大于3.4%,添加回收率为81% ~98%;多菌灵在食用菌中的检出限(LOD)和定量下限(LOQ)分别为0.03、0.10 mg/kg.该方法操作简单快速、准确度高,能够满足多菌灵残留限量标准的检测要求. 相似文献
990.
分散固相萃取-分散液液微萃取/气相色谱-串联质谱法测定蔬菜中19种有机磷农药残留 总被引:1,自引:0,他引:1
采用分散固相萃取和分散液液微萃取联用方法,建立了气相色谱-串联质谱法(GC-MS/MS)同时测定蔬菜中19种有机磷农药残留量的分析方法。分散固相萃取方法以乙腈为萃取液,以N-丙基-乙二胺(PSA)和C18为吸附剂。对影响分散液液微萃取效率的因素(萃取溶剂种类及体积、分散剂体积等)进行优化,同时分析了实验过程中添加掩蔽试剂L-古洛糖酸γ-内酯(AP)对基质效应补偿作用的影响。在最佳实验条件下,19种有机磷在辣椒和大葱中3个添加水平(0.05,0.1,0.5 mg/kg)的回收率为76.9%~126.8%,相对标准偏差为0.6%~7.3%,检出限(S/N=3)为0.10~0.50μg/kg。该方法简单、高效、重现性好、富集倍数高,可用于蔬菜中有机磷农药的快速检测。 相似文献