Spectra correction is essential for the quantification of laser-induced breakdown spectroscopy(LIBS) due to the uncertainties in plasma morphology.In this work,we determined the plasma morphology using a charge-couple...Spectra correction is essential for the quantification of laser-induced breakdown spectroscopy(LIBS) due to the uncertainties in plasma morphology.In this work,we determined the plasma morphology using a charge-coupled device camera and introduced the spectral correction method based on plasma images to a combustion environment.The plasma length,width,volume,and location were extracted from the plasma images.Using a back-scattering setup,the contribution of plasma location fluctuation to the total spectral fluctuation was mitigated.The integral intensity of the plasma image was used as a proxy of the total number density to correct the spectra.Linear relationships were established between the integral intensities of the plasma images and the spectral intensities,under different laser energy levels and gas temperatures.The image-based correction method could significantly reduce the fluctuation of raw spectral intensities when the laser energy was below 240 mJ.Compared with the correction method based on total spectral areas,the proposed method offered significant improvements in the low energy region,which promises to reduce the signal fluctuations in combustion environments while preserving the spatial resolution and mitigating the flow disturbance.展开更多
Existing commercial heat pumps,such as air conditioners(A/C)and refrigerators,possess a coefficient of performance(COP)up to and in some cases even higher than 6.However,most existing space heating techniques rely hea...Existing commercial heat pumps,such as air conditioners(A/C)and refrigerators,possess a coefficient of performance(COP)up to and in some cases even higher than 6.However,most existing space heating techniques rely heavily on fossil fuels as their direct(burning)or secondary(electric heating)energy supply.Space heating is responsible for 45%of building emissions.展开更多
Engineering materials serving in marine surroundings are inevitably corroded.The corrosive marine conditions can also be utilized to harvest kinetic ocean wave energy to solve this problem.Leveraging water–solid trib...Engineering materials serving in marine surroundings are inevitably corroded.The corrosive marine conditions can also be utilized to harvest kinetic ocean wave energy to solve this problem.Leveraging water–solid triboelectrification to harvest lowfrequency wave energy for active anticorrosion is promising.Existing techniques are efficient in harnessing environmental energy with frequencies higher than 3 Hz,whereas the dominated ocean waves with optimal wave spectral density fluctuate from 0.45 to 1.5 Hz.Herein,we proposed a highly efficient and sustainable blue energy-powered cathodic protection(BECP)strategy by fusing water–solid triboelectric nanogenerators and cathodic protection technology.Leveraging the highly efficient triboelectrification between the moving water and hydrophobic fluorinated ethylene propylene tube,we developed the built-in power module,enabling the harvest of ocean wave energy lower than 1.5 Hz.The generated volumetric current density is 28.9 mA·m^(-3),5–20 times higher than the values of the reported devices.Moreover,the proposed BECP performs comparably to conventional cathodic protection in corrosion inhibition.Significantly,the proposed approach can be easily applied to ships,buoys,and other offshore platforms to simultaneously realize blue energy harvesting and engineering material protection,providing an alternative to traditional active protection technology.展开更多
We report a highly band-selective,bifunctional meta-surface that serves as an ultra-wide perfect absorber for near-infrared(NIR)band and a visible-band sensor,based on a rational design strategy involving stacking and...We report a highly band-selective,bifunctional meta-surface that serves as an ultra-wide perfect absorber for near-infrared(NIR)band and a visible-band sensor,based on a rational design strategy involving stacking and/or grating of metals,inorganic insulators,and stimuli-responsive materials.PNIPAAm-based hydrogel was utilized as a layer of stimuli-responsive insulator,which is allowed to reversibly swell and collapse in one dimension in response to stimuli such as ambient temperature and chemical environment to empower the sensing capability in the visible band,with the perfect absorption in NIR region intact.The average absorption reached an impressive 99.4%from 780 to 2500 nm,which is attributed to the synergy of localized surface plasmon(LSP),propagating surface plasmon(PSP),and cavity mode.The reported bi-functional meta-surface is particularly attractive for band-selective solar energy harvesting,naked-eye sensing,and adaptive imaging.展开更多
基金supported by National Natural Science Foundation of China(No.51906149)the Natural Science Foundation of Shanghai(Nos.20ZR1428500,21DZ1205300)the Oceanic Interdisciplinary Program of Shanghai Jiao Tong University(No.SL2020ZD202)。
文摘Spectra correction is essential for the quantification of laser-induced breakdown spectroscopy(LIBS) due to the uncertainties in plasma morphology.In this work,we determined the plasma morphology using a charge-coupled device camera and introduced the spectral correction method based on plasma images to a combustion environment.The plasma length,width,volume,and location were extracted from the plasma images.Using a back-scattering setup,the contribution of plasma location fluctuation to the total spectral fluctuation was mitigated.The integral intensity of the plasma image was used as a proxy of the total number density to correct the spectra.Linear relationships were established between the integral intensities of the plasma images and the spectral intensities,under different laser energy levels and gas temperatures.The image-based correction method could significantly reduce the fluctuation of raw spectral intensities when the laser energy was below 240 mJ.Compared with the correction method based on total spectral areas,the proposed method offered significant improvements in the low energy region,which promises to reduce the signal fluctuations in combustion environments while preserving the spatial resolution and mitigating the flow disturbance.
文摘Existing commercial heat pumps,such as air conditioners(A/C)and refrigerators,possess a coefficient of performance(COP)up to and in some cases even higher than 6.However,most existing space heating techniques rely heavily on fossil fuels as their direct(burning)or secondary(electric heating)energy supply.Space heating is responsible for 45%of building emissions.
基金We acknowledge the financial support from the National Natural Science Foundation of China(No.51975502)the Research Grants Council of Hong Kong(Nos.SRFS2223-1S01,C1006-20W,11213320,and 11219219)+3 种基金the Shenzhen Science and Technology Innovation Council(No.SGDX20201103093005028)the Innovation and Technology Commission of HongKong(Nos.GHP/021/19SZ and GHP/092/20GD)the Science and Technology Planning Project of Guangdong Province(No.2021A0505110002)the Tencent Foundation through the XPLORER PRIZE.
文摘Engineering materials serving in marine surroundings are inevitably corroded.The corrosive marine conditions can also be utilized to harvest kinetic ocean wave energy to solve this problem.Leveraging water–solid triboelectrification to harvest lowfrequency wave energy for active anticorrosion is promising.Existing techniques are efficient in harnessing environmental energy with frequencies higher than 3 Hz,whereas the dominated ocean waves with optimal wave spectral density fluctuate from 0.45 to 1.5 Hz.Herein,we proposed a highly efficient and sustainable blue energy-powered cathodic protection(BECP)strategy by fusing water–solid triboelectric nanogenerators and cathodic protection technology.Leveraging the highly efficient triboelectrification between the moving water and hydrophobic fluorinated ethylene propylene tube,we developed the built-in power module,enabling the harvest of ocean wave energy lower than 1.5 Hz.The generated volumetric current density is 28.9 mA·m^(-3),5–20 times higher than the values of the reported devices.Moreover,the proposed BECP performs comparably to conventional cathodic protection in corrosion inhibition.Significantly,the proposed approach can be easily applied to ships,buoys,and other offshore platforms to simultaneously realize blue energy harvesting and engineering material protection,providing an alternative to traditional active protection technology.
基金supported by the Natural Science Foundation of Shanghai (Grant No. 20ZR1471700)the Oceanic Interdisciplinary Program of Shanghai Jiao Tong University (Grant No. SL2020MS009)the Prospective Research Program at Shanghai Jiao Tong University (Grant No. 19X160010008)
文摘We report a highly band-selective,bifunctional meta-surface that serves as an ultra-wide perfect absorber for near-infrared(NIR)band and a visible-band sensor,based on a rational design strategy involving stacking and/or grating of metals,inorganic insulators,and stimuli-responsive materials.PNIPAAm-based hydrogel was utilized as a layer of stimuli-responsive insulator,which is allowed to reversibly swell and collapse in one dimension in response to stimuli such as ambient temperature and chemical environment to empower the sensing capability in the visible band,with the perfect absorption in NIR region intact.The average absorption reached an impressive 99.4%from 780 to 2500 nm,which is attributed to the synergy of localized surface plasmon(LSP),propagating surface plasmon(PSP),and cavity mode.The reported bi-functional meta-surface is particularly attractive for band-selective solar energy harvesting,naked-eye sensing,and adaptive imaging.
