Influences of pulse on phase-sensitivity optical time domain reflectometer based distributed vibration sensor

Zhong, Xiang; Zhang, Chunxi; Li, Lijing; Liang, Sheng; Li, Hao; Sun, Changjun

doi:10.1016/j.optcom.2015.10.038

Cited by 15 publications

(14 citation statements)

References 18 publications

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“…The CV and GCD curves of Ag/Cu 2 O, Ag@COH, Ag@NOH, NCOH, and Ag@NCOH electrodes at different scan rates and current densities are shown in Figures S5–S9 in the Supporting Information, respectively. As observed, the GCD curves of all electrodes show well symmetry, indicating superior charge and discharge coulombic efficiency as well as electrochemical reversibility 19a. It can be noted that the relatively flat charge–discharge plateau of the amorphous hydroxide electrodes exhibit the characteristics of the battery‐type electrode 2b,3a…”

Section: Resultsmentioning

confidence: 57%

“…Therefore, in order to visually analyze the charge storage mechanism of the electrode material, the CV tests were performed with the amorphous hydroxide electrodes at different scan rates of 0.5–10 mV s −1 , as shown in Figure S10 in the Supporting Information. The kinetic analysis of the electrodes is provided according to the following equation

i = a v^{b}

Section: Resultsmentioning

confidence: 99%

“…The kinetic analysis of the electrodes is provided according to the following equation

i = a v^{b}

where i (A) is the measured current, and v (mV s −1 ) is the scan rate, a value is a constant, and b value is the speed of reaction kinetics. In general, when b = 0.5, the electrode reaction exhibits a battery behavior controlled by the ion diffusion process; when b = 1, it exhibits a capacitance or pseudocapacitance behavior controlled by the surface process . As shown in Figure a, b values of Ag@COH, Ag@NOH, NCOH, and Ag@NCOH electrodes are obtained by calculating the slope of log ( i ) vs log ( v ) diagram, which are 0.61, 0.60, 0.74, and 0.59, respectively, implying a diffusion‐controlled battery‐type behavior.…”

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Amorphous Core–Shell Nanoparticles as a Highly Effective and Stable Battery‐Type Electrode for Hybrid Supercapacitors

Cheng

Zhong

Wang

et al. 2019

Adv Materials Inter

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Herein, a silver@amorphous nickel–cobalt hydroxide (Ag@NCOH) battery‐type electrode with the morphology of core–shell nanoparticle is successfully fabricated through coordination etching and precipitating route. This electrode exhibits excellent electrochemical performance, including superior specific capacity (≈718.1 C g−1 at 1 A g−1), excellent rate capability (71.9% capacity retention at 30 A g−1), as well as good cycling stability (83.2% capacity retention over 4000 cycles) for hybrid supercapacitors. According to the results of the characterization analysis and systematic electrochemical testing, the Ag nanoparticles in core–shell structure can significantly enhance the conductivity and accelerate the rate of electron transport. Meanwhile, the nanostructures and grain boundaries of amorphous hydroxide materials can effectively improve to expose the electrochemical active sites to electrolyte. Moreover, the hybrid supercapacitor assembled from Ag@NCOH and active carbon (AC) exhibits good performance (energy density of 39.88 W h kg−1 at power density of 375 W kg−1) and superior cycling stability (85.39% capacitance retention over 9000 cycles). This work demonstrates an effective strategy to construct highly effective and stable amorphous electrode materials for hybrid supercapacitors.

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Section: Resultsmentioning

confidence: 57%

i = a v^{b}

Section: Resultsmentioning

confidence: 99%

“…The kinetic analysis of the electrodes is provided according to the following equation

i = a v^{b}

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Amorphous Core–Shell Nanoparticles as a Highly Effective and Stable Battery‐Type Electrode for Hybrid Supercapacitors

Cheng

Zhong

Wang

et al. 2019

Adv Materials Inter

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“…5(b), we can see that the amplitude and the frequency decrease slightly and totally with the increase of pulse width. When the pulse width is enlarged, the received energy of the Rayleigh backscattering light and the visibility are increased [22]. Correspondingly, the choose of reference point and observation point will be much easier.…”

Section: Different Width Of Optical Pulsementioning

confidence: 99%

“…To the best of our knowledge, so far, no attention has been paid to the effect of power change on the result of dynamic measurement. On the other hand, in order to avoid the impact of nonlinear effect and enhance the intensity of the Rayleigh back scattering signal, the pulse width is usually broadened [22]. If the optical power or the pulse width affects quantitative measurement, the conversion coefficient between the measured phase signal and the applied perturbation signal should be adjusted for every position of the fiber and different fixed optical pulse.…”

Section: Introductionmentioning

confidence: 99%

Quantitative characteristic of phase signal with changed pulse in the coherent PHI-OTDR system

Zhong¹,

Zhang²

2020

Preprint

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In the coherent -OTDR system, the phase signal is retrieved based on the reference point and the observation point which are off and closer to the two sides of step of the phase change. In the experiment, the optical pulse with the changed peak power, width or shape is injected into the fiber for interrogating the change of the quantitative characteristic of the measured phase signal. When the pulse width is fixed at 200 ns and its peak power is adjusted from 14 dBm to -23 dBm, the amplitude is slightly increased from 17.3575 rad to 17.4411 rad as long as the Rayleigh backscattering signal can be found in the electrical signal. Changing the pulse width from 260 ns to 80 ns when the peak power is fixed at 14 dBm, the maximum amplitude and the minimum amplitude of the measured phase signal are 17.4625 rad to 17.4509 rad, respectively. When the arbitrary shape of the optical pulse generated from the MZI structure with a changed delay fiber from 3 m to 6 m, the amplitude varies from 17.4558 rad to 17.4819 rad. For every measurement, the change of frequency is also small. And the small value of standard deviation supports the accuracy of the measurement. All the measurements show that the changed pulse nearly has no impact on the quantitative characteristic of the measured phase signal in the coherent -OTDR system.

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Compressed Nanolamella‐Stacked Ni(OH)₂/NiCo₂O₄ Composite as Electrode for Battery‐Type Supercapacitor

Guo

Wang

Ren

et al. 2020

Batteries & Supercaps

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Transition metal oxides/hydroxides as electrode materials for supercapacitors have drawn great attention in the past decades. However, the large volume expansion during the cycling always leads to capacity decrease and short cycle life. In this paper, a compressed Ni(OH)2/NiCo2O4 nanolamellas composite grown on nickel foam is synthesized by a one‐step hydrothermal method towards the enhanced performance of supercapacitors. The resulting Ni(OH)2/NiCo2O4 composite displays unexpectedly excellent cycle stability both in single‐electrode cycling (112 % after 90,000 cycles at 5 mA cm−2) and hybrid supercapacitor cycling (124 % after 80,000 cycles at 1 A g−1). The excellent electrochemical performances are attributed to the unique compressed nanolamella‐stacked architecture, which can not only accommodate the volume expansion, but also increase the contact area between the electrode and electrolyte.

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Influences of pulse on phase-sensitivity optical time domain reflectometer based distributed vibration sensor

Cited by 15 publications

References 18 publications

Amorphous Core–Shell Nanoparticles as a Highly Effective and Stable Battery‐Type Electrode for Hybrid Supercapacitors

Amorphous Core–Shell Nanoparticles as a Highly Effective and Stable Battery‐Type Electrode for Hybrid Supercapacitors

Quantitative characteristic of phase signal with changed pulse in the coherent PHI-OTDR system

Compressed Nanolamella‐Stacked Ni(OH)₂/NiCo₂O₄ Composite as Electrode for Battery‐Type Supercapacitor

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Influences of pulse on phase-sensitivity optical time domain reflectometer based distributed vibration sensor

Cited by 15 publications

References 18 publications

Amorphous Core–Shell Nanoparticles as a Highly Effective and Stable Battery‐Type Electrode for Hybrid Supercapacitors

Amorphous Core–Shell Nanoparticles as a Highly Effective and Stable Battery‐Type Electrode for Hybrid Supercapacitors

Quantitative characteristic of phase signal with changed pulse in the coherent PHI-OTDR system

Compressed Nanolamella‐Stacked Ni(OH)2/NiCo2O4 Composite as Electrode for Battery‐Type Supercapacitor

Contact Info

Product

Resources

About

Compressed Nanolamella‐Stacked Ni(OH)₂/NiCo₂O₄ Composite as Electrode for Battery‐Type Supercapacitor