Development of pressure-modulated EXAFS method

Chu, Shengqi; Zheng, Lirong; Che, Ruxin; Zhou, Ai; Zhang, Jing; Liu, Jing; Hu, Tiandou

doi:10.1088/1674-1137/36/2/015

Cited by 4 publications

(5 citation statements)

References 11 publications

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“…The most important characteristic of the demodulated spectrum is a $ 90 phase difference compared with the original spectrum. As simulated in former research (Ko ¨nig et al, 2012), the differential spectrum has no phase difference when coordination number and disorder changes, while 90 phase difference is typically observed if the bond length changes (Chu et al, 2012). Thus, the change in bond length may be the most important factor.…”

Section: Quantitative Analysis Of Demodulated Spectramentioning

confidence: 71%

“…For higher accuracy, the value of ! should be smaller, as in experiments with fast response such as high pressure (Chu et al, 2012), magnetostriction (Ruffoni et al, 2008), etc.…”

Section: Relationship Between Psd and Difference Spectrummentioning

confidence: 99%

“…PSD is a narrow-band technique that can filter noise, thus enhancing the signal-to-noise ratio. Our group has used a PSD-based electronic device to obtain difference XAFS via pressure modulation (Chu et al, 2012). One can also collect MES data via time-resolved methods and perform PSD analysis offline (Ko ¨nig et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

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Approach to electrochemical modulating differential extended X-ray absorption fine structure

Zhang

Shou

et al. 2022

J Synchrotron Rad

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The differential XAFS technique holds promise for detecting surface changes, which benefits many chemical applications. Phase-sensitive detection (PSD) analysis based on modulated excitation spectroscopy experiments is expected to obtain a high-quality difference spectrum, while the mathematical relationship and experiment parameters remain to be discussed. In this article, an approach to obtaining the difference spectrum from the PSD demodulated spectrum is described and its applicability in different experiment settings is discussed. The results indicate that the demodulated spectrum is almost equal to the difference spectrum when the modulating period is 20 times larger than the relaxation time constant. This approach was subsequently applied to an electrochemical modulation experiment and the demodulated spectrum was analyzed. A reversible lattice shrinking is observed via the fitting of demodulated spectra, which is proportional to the charge amount on the electrode. This approach could be used to quantitatively analyze the modulated excitation XAS data and holds promise for a wide range of electrochemical studies.

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Section: Quantitative Analysis Of Demodulated Spectramentioning

confidence: 71%

“…For higher accuracy, the value of ! should be smaller, as in experiments with fast response such as high pressure (Chu et al, 2012), magnetostriction (Ruffoni et al, 2008), etc.…”

Section: Relationship Between Psd and Difference Spectrummentioning

confidence: 99%

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Approach to electrochemical modulating differential extended X-ray absorption fine structure

Zhang

Shou

et al. 2022

J Synchrotron Rad

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“…In this study, Sunhe River was selected as the research 1 subject for urban river ecological restoration. Through the comprehensive technology of artificial aeration [9], artificial floating island [10,11] and microbial agents [12] (O-AFI-MA), the effect and influence of the O-AFI-MA on Black and odorous Water Body treatment were investigated.…”

Section: Introductionmentioning

confidence: 99%

The effect of ecological restoration based artificial reoxygenation on water quality Improvement of urban river water

Luo

Hu²,

Li³

et al. 2018

MATEC Web Conf.

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Urban river pollution sources such as Combined Sewer Overflows (CSOs) or Illegally Discharging of Industrial Waste (IDIW) are generally hard to control on-site and cause serious water quality degradation problems across the nation. Therefore developing effective in-situ remediation techniques for urban rivers is of great interest. In this research we combined river reoxygenation, artificial floating island and microbial agents technologies (O-AFI-MA) to developed a comprehensive in-situ remediation technique and obtained water quality data from Sunhe River case study to evaluate its effectiveness. Our discovery indicates that the O-AFI-MA technique effectively improves water quality by reducing chemical oxygen demand (CODCr), total phosphorous (TP), ammonium nitrogen (NH4+-N) level by 45.9%, 61.31, 7.66% respectively and our technique enhances the natural degradation rate by raising the dissolved oxygen (DO) level from 2.8mg/L to 10mg/L upstream. The case study suggests that the sediment accumulation from CSOs and the subsequent internal source release causes great water quality degradation for Sunhe River. We also tested combinatory microbial agents, physical adsorption and multimedia bio-filter bed technologies independently on site to improve the ammonium nitrogen and total phosphorous removal rate of our technique, and the multimedia bio-filter bed is found to be most effective.

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“…Recently, it has been applied in XAFS experiments [6−10]. A periodic external perturbation, such as light [6], magnetic field [7], temperature [8], or high pressure [9,10], has been verified to enhance the XAFS signal of internal structure. In 2001, an energymodulation technique [11] for XAFS spectroscopy was first developed where another monochromator together with a piezo-driven oscillation stage were added to the beamline and used to modulate the energy.…”

Section: Introductionmentioning

confidence: 99%