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1.
Appl Opt ; 54(25): 7477-82, 2015 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-26368865

RESUMEN

We propose a new digital holography based on the lateral shearing interference concept to remove the total aberrations from the reference wave, illumination wave, and the optical elements. It uses three mutually shifted image holograms of the object that are divided from each other to obtain phase differences. The phase aberration can be removed and the original sample phase can be reconstructed by the phase differences. Then, the influence of the stage moving imprecision on the reconstruction quality is analyzed. Optical experiments verified that the proposed method can totally remove the phase aberrations. As a result, the proposed method could be used for ultra-precise optical measurement through eliminating optical phase aberration to increase the measurement accuracy.

2.
J Phys Chem A ; 117(40): 10211-7, 2013 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-24079920

RESUMEN

We developed a new nanocluster (NC) ion source based on the high-power impulse magnetron sputtering (HiPIMS) technique coupled with a gas flow cell reactor. Silver NC anions (Ag(n)(-)) with a maximum intensity of 5.5 nA (Ag11(-)) are generated with the size ranging from the atomic anion to the 70-mer, which is well-controlled by simply adjusting the peak power and repetition rate of the HiPIMS. By time-resolved density profiles of Ag(n)(-), we find that the ion beam generated by HiPIMS is characterized by individual 100 ms duration "bunches" below a repetition rate of 10 Hz, which is well-thermalized with a group velocity of 5 m/s. The high intensity of the NCs is attributable to the high ionization fraction by this HiPIMS ion source, while the underlying mechanism of the flexible size tuning of the ion source is understood by time-resolved mass spectrometry coupled with the sequential growth mechanism; the increment of the density of the target species in the bunches with the peak power and the overlapping of the bunches with the repetition rate cause the formation of large NCs.

3.
Biosensors (Basel) ; 12(5)2022 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-35624583

RESUMEN

Metallic nanoclusters (NCs) have been predicted to achieve the best Surface-Enhanced Raman Scattering (SERS) due to the controllable amount of atoms and structures in NCs. The Local Surface Plasmon Resonance (LSPR) effect on silver metal NCs (Agn) enables it to be a promising candidate for manipulating the LSPR peak by controlling the size of NCs, which in turn demands a full understanding of the formation mechanism of Agn. Here, we apply an extended Smoluchowski rate equation coupled with a fragmentation scheme to investigate the growth of size-selected silver NCs generated via a modulated pulsed power magnetron sputtering (MPP-MSP). A temperature-dependent fragmentation coefficient D is proposed and integrated into the rate equations. The consistency between the computational and experimental results shows that in relative low peak power (Pp≤800 W), the recombination of cation and anion species are the dominant mechanism for NC growth. However, in the higher Pp region (≥800 W), the fragmentation mechanism becomes more impactful, leading to the formation of smaller NCs. The scanning electron microscopy observation shows the Ag36 is successfully soft-landed and immobilized on a strontium titanate crystal, which facilitates the application of the Agn/STO to the SERS research.


Asunto(s)
Plata , Espectrometría Raman , Plata/química , Espectrometría Raman/métodos , Resonancia por Plasmón de Superficie/métodos
4.
Zhongguo Zhong Yao Za Zhi ; 35(16): 2103-5, 2010 Aug.
Artículo en Zh | MEDLINE | ID: mdl-21046739

RESUMEN

OBJECTIVE: To develop identification and assay methods of Franchet groundcherry. METHOD: TLC method was used to identify of physalin L in the sample using high performance silica gel G plate and a mixture of chloroform-acetone-methanol (25:1:1) as a developing solvent. In the chromatogram, physalin L showed a distinct fluorescence spot under UV 365 nm with good separation. In the HPLC method, luteoloside was separated on a Venusil XBP C18 (4.6 mm x 250 mm, 5 microm) column with acetonitrile-0. 2% phosphoric acid (20:80) as the mobile phase with flow rate of 1 mL x min(-1). The detection wavelength was set at 350 nm. RESULT: For the HPLC quantitation method, the calibration curve of luteoloside displayed ideal linearity over the range of 0.50-249.40 mg x L(-1) with the regression equation of Y = 55,313X + 3.1641 (r = 1.000). The average recovery of luteoloside was 98.79% with a RSD of 1.1%. And the intra-day and inter-day precisions were less than 2%. CONCLUSION: The TLC identification and HPLC determination were sensitive, reliable and repeatable and can be applied for the quality evaluation and assessment of Franchet Groundcherry Calyx.


Asunto(s)
Bignoniaceae/química , Cromatografía Líquida de Alta Presión , Cromatografía en Capa Delgada , Medicamentos Herbarios Chinos/análisis , Oligosacáridos/análisis , Reproducibilidad de los Resultados
5.
Sci Rep ; 6: 21628, 2016 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-26876362

RESUMEN

We report bulk superconductivity at 1.0 K in a low-dimensional ternary telluride Ta3Pd3Te14 containing edge-sharing PdTe2 chains along crystallographic b axis, similar to the recently discovered superconductor Ta4Pd3Te16. The electronic heat capacity data show an obvious anomaly at the transition temperature, which indicates bulk superconductivity. The specific-heat jump is ΔC/(γ(n)T(c)) ≈ 1.35, suggesting a weak coupling scenario. By measuring the low-temperature thermal conductivity, we conclude that Ta3Pd3Te14 is very likely a dirty s-wave superconductor. The emergence of superconductivity in Ta3Pd3Te14 with a lower T(c), compared to that of Ta4Pd3Te16, may be attributed to the lower density of states.

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