In order to decrease the consumption of reagents and silicon during removal of surface contamination before silicon texturing in solar cell manufacturing industry, a new low-cost surface treatment approach of electroc...In order to decrease the consumption of reagents and silicon during removal of surface contamination before silicon texturing in solar cell manufacturing industry, a new low-cost surface treatment approach of electrochemical cleaning technique(ECT) is reported. In this technique, a powerful oxidizing electrolyte was obtained from the electrochemical reaction on Boron-doped Diamond(BDD) electrodes, and applied during removal of surface contaminations on silicon wafer surfaces. The slightly polished monocrystalline silicon surfaces after cleaning were compared with the ones of primal silicon wafers. The measurement results show that ECT is quite efficient in removing NaCl and organic contaminants. After cleaning, the contrast test was conducted for the textured silicon wafers with/without pre-treatment(polish) separately. The results show that the size of pyramids on the surface without traditional polishing process is homogeneous and smaller than 4μm, and the average surface reflectance is much lower in the wavelength range from 400nm to 800nm. Therefore, the new technique can save silicon material, and effectively avoid optical losses for improving photoconversion effect of solar cells.展开更多
Purpose To meet the stringent requirements for high-quality processing of focusing mirror molds and reproduction mirrors,specific cleaning procedures must be both accurate and efficient.Methods This study examines the...Purpose To meet the stringent requirements for high-quality processing of focusing mirror molds and reproduction mirrors,specific cleaning procedures must be both accurate and efficient.Methods This study examines the stability and consistency of the removal rate throughout the polishing process by analyzing changes in the composition of the polishing slurry at various stages.Infrared spectroscopy was used to measure the chemical groups of compounds on the mandrel surface and assess its stress state.Additionally,the adsorption mechanism at the interface was explored in detail.Results and Conclusion The study investigates ultra-precision polishing of nickel–phosphorus alloy,focusing on factors influencing the water film formation ability on the workpiece surface.X-ray electron spectroscopy was employed to analyze the mandrel before and after the cleaning process.The effectiveness of the cleaning process was evaluated by comparing its surface removal effect with that of the polishing process.展开更多
Scrap metals are typically covered with surface contaminants,such as paint,dust,and rust,which can significantly affect the emission spectrum during laser-induced breakdown spectroscopy(LIBS)based sorting.In this stud...Scrap metals are typically covered with surface contaminants,such as paint,dust,and rust,which can significantly affect the emission spectrum during laser-induced breakdown spectroscopy(LIBS)based sorting.In this study,the effects of paint layers on metal surfaces during LIBS classification were investigated.LIBS spectra were collected from metal surfaces painted with black and white paints by ablation with a nanosecond pulsed laser(wavelength=1064 nm,pulse width=7 ns).For the black-painted samples,the LIBS spectra showed a broad background emission,emission lines unrelated to the target metals,large shot-to-shot variation,and a relatively low signal intensity of the target metal,causing poor classification accuracy even at high shot numbers.Cleaning the black paint layer by ablating over a wide area prior to LIBS analysis resulted in high classification accuracy with fewer shot numbers.A method to determine the number of cleaning shots necessary to obtain high classification accuracy and high throughput is proposed on the basis of the change in LIBS signal intensity during cleaning shots.For the white-painted samples,the paint peeled off the metal surface after the first shot,and strong LIBS signals were measured after the following shot,which were attributed to the nanoparticles generated by the ablation of the paint,allowing an accurate classification after only two shots.The results demonstrate that different approaches must be employed depending on the paint color to achieve high classification accuracy with fewer shot numbers.展开更多
Contaminants that are floating on the surface of the ocean are subjected to the action of random waves.In the literature,it has been asserted by researchers that the random wave action will lead to a dispersion mechan...Contaminants that are floating on the surface of the ocean are subjected to the action of random waves.In the literature,it has been asserted by researchers that the random wave action will lead to a dispersion mechanism through the induced Stokes drift,and that this dispersion mechanism may have the same order of significance comparable with the others means due to tidal currents and wind.It is investigated whether or not surface floating substances will disperse in the random wave environment due to the induced Stokes drift.An analytical derivation is first performed to obtain the drift velocity under the random waves.From the analysis,it is shown that the drift velocity is a time-independent value that does not possess any fluctuation given a specific wave energy spectrum.Thus,the random wave drift by itself should not have a dispersive effect on the surface floating substances.Experiments were then conducted with small floating objects subjected to P-M spectral waves in a laboratory wave flume,and the experimental results reinforced the conclusion drawn.展开更多
A solar PV panel works with maximum efficiency only when it is operated around its optimum operating point or maximum power point.Unfortunately,the performance of the solar cell is affected by several factors like sun...A solar PV panel works with maximum efficiency only when it is operated around its optimum operating point or maximum power point.Unfortunately,the performance of the solar cell is affected by several factors like sun direction,solar irradiance,dust accumulation,module temperature,as well as the load on the system.Dust deposition is one of the most prominent factors that influence the performance of solar panels.Because the solar panel is exposed to the atmosphere,dust will accumulate on its surface,reducing the quantity of sunlight reaching the solar cell and diminishing output.In the proposed work,a detailed investigation of the performance of solar PV modules is carried out under the tropical climatic condition of Chennai,India,where the presence of dust particles is very high.The data corresponding to four different dust samples of various densities at four solar irradiation levels of 220,525,702,and 905 W/m^(2)are collected,and performance analysis is carried out.Based on the analysis carried out,the maximum power loss is found to be 73.51%,66.29%,65.46%,and 61.42%,for coal,sand,brick powder,and chalk dust respectively.Hence,it can be said that coal dust contributes to the maximum power loss among all four dust samples.Due to heat dissipation produced by dust deposition,the performance of solar PV modules is degraded as the temperature rose.展开更多
The genotoxic activities of effluents from drainage water treatment plants were examined by using the novel <em>umu</em> tester strain NM8001, which lacks <em>MutMst</em> genes. To enhance the ...The genotoxic activities of effluents from drainage water treatment plants were examined by using the novel <em>umu</em> tester strain NM8001, which lacks <em>MutMst</em> genes. To enhance the sensitivity of the LacZ assay, a BugBuster mix protein extraction reagent and TokyoGreen-<em>β</em> Gal for a fluorescence-galactosidase substrate were applied. Of the 24 sampling locations present in Kanagawa prefecture, Japan, water extracts from nine sampling points showed apparent genotoxic activities without metabolic activation. In contrast, water extracts from the upper sites of these water treatment plants did not show any significant genotoxic activities. The selected samples with genotoxic activity did not show significant mutagenicity toward Ames strains TA98 and TA100. Genotoxicity was also well correlated with the activity of a classical <em>umu </em>strain of TA1535/pSK1002;these findings indicate that the genotoxicity induced by oxidative damage was not a significant component of the genotoxicity.展开更多
The surface contamination layer on mirrors can cause significant degradation of the optical performance, which is widely observed in applications, particularly in the fabrication of X-ray focusing telescopes. In this ...The surface contamination layer on mirrors can cause significant degradation of the optical performance, which is widely observed in applications, particularly in the fabrication of X-ray focusing telescopes. In this paper, we study the natural contamination layer arising from adsorption precipitation of hydrocarbons or other organic and water molecules in the absence of any external factor. Temporal evolution of the layer formed on super-smooth fused silica, borosilicate glass, and silicon substrates is studied by X-ray reflectometry, atomic force microscopy, and transmission electron microscopy for a one-year period after surface cleaning. The general characteristics of adhesion layer growth are established and discussed. The reconstructed dielectric constant profiles demonstrate that an increase in the adhesion layer thickness, deposited mass and density over time obeys power laws with extremely small exponents. Therefore, the adhesion layer growth is rapid immediately after surface cleaning, with a - 1 nm thick layer formed within the first day on all three substrates studied, while the layer density is low （- 1 g/cm^3）. The layer growth on the fused silica and silicon substrates became very slow in the succeeding days, with only a 1.4-1.5 nm thick layer and 1.2-1.3 g/cm^3 density after one year of storage in air. At the same time, the adhesion layer growth on the glass substrate showed unexpected acceleration about two months after cleaning, so that the layer thickness reached - 2.2 nm after one year of storage. The reason for this effect, which is connected with leaching of the glass, is discussed briefly.展开更多
This short perspective summarizes recent findings on the role of residual lithium present on the surface of layered Ni-rich oxide cathode materials in liquid-and solid-electrolyte based batteries,with emphasis placed ...This short perspective summarizes recent findings on the role of residual lithium present on the surface of layered Ni-rich oxide cathode materials in liquid-and solid-electrolyte based batteries,with emphasis placed on the carbonate species.Challenges and future research opportunities in the development of carbonate-containing protective nanocoatings for inorganic solid-state battery applications are also discussed.展开更多
Enormous research focusing on solid-state electrolyte promotes the development of solid-state batteries.Compared to lithium-ion batteries using liquid electrolyte,the solid-state batteries feature the hi gh energy den...Enormous research focusing on solid-state electrolyte promotes the development of solid-state batteries.Compared to lithium-ion batteries using liquid electrolyte,the solid-state batteries feature the hi gh energy density and non-flammability,which accelerates the revolution in portable electronics and transportation.Garnet-type Li_(7)La_(3)Zr_(2)O_(12)(LLZO)solid-state electrolyte is considered as the promising solid-state electrolyte due to high ionic conductivity,Li transference number and shear modulus.However,surface contaminant and poor contact with lithium inhibit its practical application in lithium metal batteries.The review provides a brief introduction about structure and properties of LLZO.Then,we conclude the modification strategies for increasing ionic conductivity,enhancing interfacial contact and inhibiting lithium dendrite.At last,the challenge and perspectives are discussed for development of LLZO in solid-state batteries.展开更多
基金National Natural Science Foundation of China(10676008)Specialized Research Fund for the Doctoral Program of Higher Education of China(20050080007)
文摘In order to decrease the consumption of reagents and silicon during removal of surface contamination before silicon texturing in solar cell manufacturing industry, a new low-cost surface treatment approach of electrochemical cleaning technique(ECT) is reported. In this technique, a powerful oxidizing electrolyte was obtained from the electrochemical reaction on Boron-doped Diamond(BDD) electrodes, and applied during removal of surface contaminations on silicon wafer surfaces. The slightly polished monocrystalline silicon surfaces after cleaning were compared with the ones of primal silicon wafers. The measurement results show that ECT is quite efficient in removing NaCl and organic contaminants. After cleaning, the contrast test was conducted for the textured silicon wafers with/without pre-treatment(polish) separately. The results show that the size of pyramids on the surface without traditional polishing process is homogeneous and smaller than 4μm, and the average surface reflectance is much lower in the wavelength range from 400nm to 800nm. Therefore, the new technique can save silicon material, and effectively avoid optical losses for improving photoconversion effect of solar cells.
基金the Strategic Priority Program on Space Science China,the Chinese Academy of Science,(Grant No.XDA15020106 and XDA15020501)the National Natural Science Foundation of China,grant number 42327802.
文摘Purpose To meet the stringent requirements for high-quality processing of focusing mirror molds and reproduction mirrors,specific cleaning procedures must be both accurate and efficient.Methods This study examines the stability and consistency of the removal rate throughout the polishing process by analyzing changes in the composition of the polishing slurry at various stages.Infrared spectroscopy was used to measure the chemical groups of compounds on the mandrel surface and assess its stress state.Additionally,the adsorption mechanism at the interface was explored in detail.Results and Conclusion The study investigates ultra-precision polishing of nickel–phosphorus alloy,focusing on factors influencing the water film formation ability on the workpiece surface.X-ray electron spectroscopy was employed to analyze the mandrel before and after the cleaning process.The effectiveness of the cleaning process was evaluated by comparing its surface removal effect with that of the polishing process.
基金supported by the R&D Center for Valuable Recycling (Global-Top R&D Program)of the Ministry of Environment (No.2016002250003)。
文摘Scrap metals are typically covered with surface contaminants,such as paint,dust,and rust,which can significantly affect the emission spectrum during laser-induced breakdown spectroscopy(LIBS)based sorting.In this study,the effects of paint layers on metal surfaces during LIBS classification were investigated.LIBS spectra were collected from metal surfaces painted with black and white paints by ablation with a nanosecond pulsed laser(wavelength=1064 nm,pulse width=7 ns).For the black-painted samples,the LIBS spectra showed a broad background emission,emission lines unrelated to the target metals,large shot-to-shot variation,and a relatively low signal intensity of the target metal,causing poor classification accuracy even at high shot numbers.Cleaning the black paint layer by ablating over a wide area prior to LIBS analysis resulted in high classification accuracy with fewer shot numbers.A method to determine the number of cleaning shots necessary to obtain high classification accuracy and high throughput is proposed on the basis of the change in LIBS signal intensity during cleaning shots.For the white-painted samples,the paint peeled off the metal surface after the first shot,and strong LIBS signals were measured after the following shot,which were attributed to the nanoparticles generated by the ablation of the paint,allowing an accurate classification after only two shots.The results demonstrate that different approaches must be employed depending on the paint color to achieve high classification accuracy with fewer shot numbers.
基金The State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Research Foundation of China under contract No.2015491311
文摘Contaminants that are floating on the surface of the ocean are subjected to the action of random waves.In the literature,it has been asserted by researchers that the random wave action will lead to a dispersion mechanism through the induced Stokes drift,and that this dispersion mechanism may have the same order of significance comparable with the others means due to tidal currents and wind.It is investigated whether or not surface floating substances will disperse in the random wave environment due to the induced Stokes drift.An analytical derivation is first performed to obtain the drift velocity under the random waves.From the analysis,it is shown that the drift velocity is a time-independent value that does not possess any fluctuation given a specific wave energy spectrum.Thus,the random wave drift by itself should not have a dispersive effect on the surface floating substances.Experiments were then conducted with small floating objects subjected to P-M spectral waves in a laboratory wave flume,and the experimental results reinforced the conclusion drawn.
文摘A solar PV panel works with maximum efficiency only when it is operated around its optimum operating point or maximum power point.Unfortunately,the performance of the solar cell is affected by several factors like sun direction,solar irradiance,dust accumulation,module temperature,as well as the load on the system.Dust deposition is one of the most prominent factors that influence the performance of solar panels.Because the solar panel is exposed to the atmosphere,dust will accumulate on its surface,reducing the quantity of sunlight reaching the solar cell and diminishing output.In the proposed work,a detailed investigation of the performance of solar PV modules is carried out under the tropical climatic condition of Chennai,India,where the presence of dust particles is very high.The data corresponding to four different dust samples of various densities at four solar irradiation levels of 220,525,702,and 905 W/m^(2)are collected,and performance analysis is carried out.Based on the analysis carried out,the maximum power loss is found to be 73.51%,66.29%,65.46%,and 61.42%,for coal,sand,brick powder,and chalk dust respectively.Hence,it can be said that coal dust contributes to the maximum power loss among all four dust samples.Due to heat dissipation produced by dust deposition,the performance of solar PV modules is degraded as the temperature rose.
文摘The genotoxic activities of effluents from drainage water treatment plants were examined by using the novel <em>umu</em> tester strain NM8001, which lacks <em>MutMst</em> genes. To enhance the sensitivity of the LacZ assay, a BugBuster mix protein extraction reagent and TokyoGreen-<em>β</em> Gal for a fluorescence-galactosidase substrate were applied. Of the 24 sampling locations present in Kanagawa prefecture, Japan, water extracts from nine sampling points showed apparent genotoxic activities without metabolic activation. In contrast, water extracts from the upper sites of these water treatment plants did not show any significant genotoxic activities. The selected samples with genotoxic activity did not show significant mutagenicity toward Ames strains TA98 and TA100. Genotoxicity was also well correlated with the activity of a classical <em>umu </em>strain of TA1535/pSK1002;these findings indicate that the genotoxicity induced by oxidative damage was not a significant component of the genotoxicity.
基金Supported by the National Key R&D Program of China(2016YFA0401304)the National Natural Science Foundation of China(NSFC)(61621001,U1731242,U1732268)the Ministry of Science and Higher Education of Russian Federation within the State assignment FSRC “Crystallography and Photonics” RAS
文摘The surface contamination layer on mirrors can cause significant degradation of the optical performance, which is widely observed in applications, particularly in the fabrication of X-ray focusing telescopes. In this paper, we study the natural contamination layer arising from adsorption precipitation of hydrocarbons or other organic and water molecules in the absence of any external factor. Temporal evolution of the layer formed on super-smooth fused silica, borosilicate glass, and silicon substrates is studied by X-ray reflectometry, atomic force microscopy, and transmission electron microscopy for a one-year period after surface cleaning. The general characteristics of adhesion layer growth are established and discussed. The reconstructed dielectric constant profiles demonstrate that an increase in the adhesion layer thickness, deposited mass and density over time obeys power laws with extremely small exponents. Therefore, the adhesion layer growth is rapid immediately after surface cleaning, with a - 1 nm thick layer formed within the first day on all three substrates studied, while the layer density is low （- 1 g/cm^3）. The layer growth on the fused silica and silicon substrates became very slow in the succeeding days, with only a 1.4-1.5 nm thick layer and 1.2-1.3 g/cm^3 density after one year of storage in air. At the same time, the adhesion layer growth on the glass substrate showed unexpected acceleration about two months after cleaning, so that the layer thickness reached - 2.2 nm after one year of storage. The reason for this effect, which is connected with leaching of the glass, is discussed briefly.
基金F Strauss acknowledges financial support from the Fonds der Chemischen Industrie(FCI)through a Liebig fellowship.This work was partially supported by BASF SE.
文摘This short perspective summarizes recent findings on the role of residual lithium present on the surface of layered Ni-rich oxide cathode materials in liquid-and solid-electrolyte based batteries,with emphasis placed on the carbonate species.Challenges and future research opportunities in the development of carbonate-containing protective nanocoatings for inorganic solid-state battery applications are also discussed.
基金financially supported by the National Natural Science Foundation of China(Grant No.51672156)Local Innovative Research Teams Project of Guangdong Pearl River Talents Program(Grant No.2017BT01N111)Shenzhen Technical Plan Project(Grant Nos.JCYJ20170412170706047,JCYJ20170307153806471 and GJHS20170314165324888)
文摘Enormous research focusing on solid-state electrolyte promotes the development of solid-state batteries.Compared to lithium-ion batteries using liquid electrolyte,the solid-state batteries feature the hi gh energy density and non-flammability,which accelerates the revolution in portable electronics and transportation.Garnet-type Li_(7)La_(3)Zr_(2)O_(12)(LLZO)solid-state electrolyte is considered as the promising solid-state electrolyte due to high ionic conductivity,Li transference number and shear modulus.However,surface contaminant and poor contact with lithium inhibit its practical application in lithium metal batteries.The review provides a brief introduction about structure and properties of LLZO.Then,we conclude the modification strategies for increasing ionic conductivity,enhancing interfacial contact and inhibiting lithium dendrite.At last,the challenge and perspectives are discussed for development of LLZO in solid-state batteries.
