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1

Focus shaping of Weierstrass solid immersion lens by an axisymmetric Bessel-modulated Gaussian beam

Dong X., Geng T., Zhuang S.

Optica Applicata

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2013

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Vol. 43, nr 2

s. 247--259

EN

Weierstrass solid immersion lens (SIL) has been used to obtain superresolution because a smaller focal size is desirable. In this paper, focus shaping of Weierstrass SIL illuminated by an axisymmetric Bessel-modulated Gaussian beam (QBG beam) is investigated. It has been found theoretically that the sharper focusing of Weierstrass SIL disappears for a certain beam order of QBG beam. For case of a smaller beam order, the focus still locates on the plane of Weierstrass SIL and Weierstrass SIL still plays a tighter focusing role. However, when the beam order increases continuously, the focus lefts the plane of Weierstrass SIL, and shifts along an optical axis considerably. In addition, under condition of the higher beam order, the dependence of the focal shift on the beam order is nearly linear, which may be used to alter a focal position conveniently.

2

Focus shaping of Bessel-Gauss beam with radial varying polarization

Gao X., Fu R., Shen H., Dong X., Geng T., Zhuang S.

Optica Applicata

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2012

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Vol. 42, nr 3

481-491

EN

Focusing properties of Bessel-Gauss beam with radial varying polarization are investigated based on vector diffraction theory in this article. The polarization angle formed by polarization direction and radial coordinate is the function of the radial distance in pupil plane, and one polarization parameter indicates the speed of change of polarization angle. It was found that the intensity distribution in focal region can be altered considerably by the beam parameter and polarization parameter. For a small beam parameter, the focal spot broadens transversely, distorts into ring focus, and then evolves back into focal spot on increasing polarization parameter. When beam parameter gets higher, focal pattern becomes complicated and the focus evolution principle with increasing beam parameter also changes significantly. Some novel focal patterns may appear, including multiple intensity rings, dark hollow focus, cylindrical crust focus.

3

Selective solid-phase extraction of Hg(II) using silica gel surface : imprinting technique

Zheng H., Geng T., Hu L.

Chemia Analityczna

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2008

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Vol. 53, No. 5

673-687

EN

A new ion-imprinted amino-functionalized silica gel sorbent was synthesized by surface-imprinting technique for preconcentration and separation of Hg(II) prior to its determination by inductively coupled plasma optical emission spectrometry (ICP—OES). Compared to the traditional solid sorbents and non-imprinted polymer particles, the ion-imprinted polymers (IlPs) have higher adsorption capacity and selectivity for Hg(II). The maximum static adsorption capacity of the imprinted and non-imprinted sorbent for Hg(II) was 29.89 mg g-1 and 11.21 mg g-1, respectively. The highest selectivity coefficient for Hg(II) in the presence of Zn(II) exceeded 230. The detection limit (3a) of the method was 0.25 μg L-1. The relative standard deviation of the method was 2.5% for eight replicate determinations of 10 ug of Hg2+ in 200 mL-in-volume water sample. The procedure was validated byperforming the analysis of the certified river sediment sample (GBW 08603, China) using the standard addition method. The developed method was also successfully applied to the determination of trace mercury in Chinese traditional medicine and water samples with satisfactory results.

PL

Stosując technikę modyfikowania powierzchni grupami aminowymi otrzymano nowy, jonowo dopasowany żel krzemionkowy służący do zatężania i oddzielania Hg(II) przed jej oznaczeniem za pomocą optycznej spektrometrii emisyjnej ze wzbudzeniem w plazmie indukcyjnie sprzężonej (1CP—OES). W porównaniu z tradycyjnymi, stałymi sorbentami i niemodyfikowanymi polimerami, polimery dopasowane jonowo (ion-imprinted polymers - IIPs) mają większą pojemność adsorpcyjną oraz selektywność względem Hg(II). Maksymalna statyczna pojemność adsorpcyjną Hg(Il) w przypadku sorbentu modyfikowanego i niemodyfikowanego wynosiła odpowiednio 29,89 mg gg-1i 11,21 mg gg-1. Najwyższy współczynnik selekty wności Hg(lł) względem Zn(II) przekraczał 230. Granica wykrywalności (3a) wynosiła 0.25 μg L-1. Względne odchylenie standardowe, obliczone z 8 oznaczeń próbki wody zawierającej w 200 mL lO μg HgHg2+, wynosiło 2,5%. Metodę zwalidowano wykonując analizę certyfikowanych próbek osadów rzecznych (GBW 08603, Chiny) metodą dodatku wzorca. Opracowaną metodę z powodzeniem zastosowano do oznaczania śladów rtęci w tradycyjnej chińskiej medycynie oraz w próbkach wody.