Industrial effluents from textile, tannery or printing activities often have a significant pollutant load composed of dyes that are difficult to biodegrade. These dyes pose a threat to the environment. To overcome thi...Industrial effluents from textile, tannery or printing activities often have a significant pollutant load composed of dyes that are difficult to biodegrade. These dyes pose a threat to the environment. To overcome this problem, various processes have been developed to eliminate these dyes in wastewater before their release into nature. Conventional biological or physical processes most often prove to be ineffective and expensive. It is therefore necessary to resort to other processes such as advanced oxidation processes (POA). This work therefore focuses on the study of the influence of clay in the degradation of Methylene Blue by the photo-Fenton process which is one of the advanced oxidation processes (POA), with the source of irradiation, natural light. To do this, two clays from Côte d’Ivoire referenced AB and Aga were the subject of a physicochemical and mineralogical characterization. The results showed that Aga clay is composed of 75.43% quartz, 12.72% kaolinite, 8.75% illite and 3.12% goethite and AB clay consists of 61, 36% kaolinite, 28.6% quartz and 10.10% illite. Under natural light irradiation the optimal amounts of Fenton reagents (iron: 10 mg;H2O2: 0.1 mL) were determined. Finally, the addition of clay to the photo-Fenton process made it possible to improve the degradation of the pollutant (Methylene Blue). Indeed, the yield increased from 92% for the photo-Fenton process to 98.43% with the addition of AB clay and 98.13% for the addition of Aga clay. The results of the degradation kinetics clearly show that the degradation follows the pseudo-second order kinetics with correlation coefficients greater than 0.99.展开更多
In this work, the degradation of 2-chloro-4,6-diamino-1,3,5-triazine in aqueous solutions by photo-Fenton process has been investigated. The preliminary results have shown that the degradation of 2-chloro-4,6-diamino-...In this work, the degradation of 2-chloro-4,6-diamino-1,3,5-triazine in aqueous solutions by photo-Fenton process has been investigated. The preliminary results have shown that the degradation of 2-chloro-4,6-diamino-1,3,5-triazine by photo-Fenton process is more rapid and more effective than Fenton and UV/H2O2 processes. The effects of certain experimental parameters on kinetics and efficiency of the degradation of 2-chloro-4,6,-diamino-1,3,5-triazine by photo-Fenton process, have been evaluated. Under optimal conditions, photo-Fenton process achieved more than 90% of chloride release and about 30% of nitrate formation. The results of total organic carbon (TOC) and total Kjeldahl nitrogen (TKN) analyses have shown that no carbon dioxide and ammonia are formed during photo-Fenton treatment of aqueous solutions containing 40 mg/L triazine. These results indicate that only substituent groups of triazine ring are released;however, nitrogen atoms of triazine ring remain unaffected. A simple mechanism of degradation of 2-chloro-4,6-diamino-1,3,5-triazine has been proposed. The degradation starts by a rapid release of chlorine atoms as chloride ions to form 2-hydroxy-4,6-diamino-1,3,5-triazine. The amino groups of 2-hydroxy-4,6-diamino-1,3,5-triazine undergo are oxidized into nitro groups by hydroxyl radicals to form 2-hydroxy-4,6-dinitro-1,3,5-triazine which undergoes a slow release of nitro groups and their substitution with hydroxyl groups to form cyanuric acid and nitrate ions. The degradation of cyanuric acid by photo-Fenton process has also been investigated. The results of TOC and TKN analyzes show that no carbon dioxide is formed during the treatment.展开更多
The present work evaluated the use of photo-Fenton process for the treatment of kraft pulp mill effluent. The photo-Fenton best operating conditions, such as pH, concentration, and H2O2: Fe2+ ratio were evaluated. The...The present work evaluated the use of photo-Fenton process for the treatment of kraft pulp mill effluent. The photo-Fenton best operating conditions, such as pH, concentration, and H2O2: Fe2+ ratio were evaluated. The efficiency of the treatment was measured by COD (chemical oxygen demand) removal. The results showed that the optimum pH for the photo-Fenton process was equal to 3. The increase in H2O2 application resulted in an efficiency increase of the photo-Fenton process, although this was not a directly proportional relation. For most cases, the H2O2: Fe2+ proportion of 100:1 yielded the best results for COD removal. Solar radiation was more efficient than artificial UV to the COD removal. During the treatment the organic matter of the effluent was more oxidized than mineralized, showing a higher removal of COD than BOD (biochemical oxygen demand) and TOC (total organic carbon), respectively. So, photo-Fenton process increased the BOD/ COD ration but decreased the BOD/TOC ratio.展开更多
Culturability and viability techniques such as plate count on solid agar (PC), Most Probable Number (MPN) and Direct Viable Count-Fluorescence in Situ Hybridation (DVC FISH) were used to study the inactivation of Salm...Culturability and viability techniques such as plate count on solid agar (PC), Most Probable Number (MPN) and Direct Viable Count-Fluorescence in Situ Hybridation (DVC FISH) were used to study the inactivation of Salmonella typhimurium by photo-Fenton process at pH 5.5. In the presence of only simulated solar irradiation (500 W·m-2), S. typhimurim showed that both culturability measured by MPN and viability (measured by DVC FISH) underwent just a slight decreasing of 2 and 1 log respectively after 240 min of light exposition while culturability measured by PC did not show any change. Results after 48 h of dark conditions did not reveal re-growth. However, when experiment was carried out in the presence of 2 mg L-1 of Fe3+ and 20 mg L-1 of H2O2 and pH 5.5, culturability was strongly affected after 240 min of simulated solar irradiation;nevertheless, viability was only slightly altered (~1 log). During dark period of 48 h changes on culturability and viability were not observed. On the other hand, it was also found that sugar metabolism was affected rather the amino-acids in S. typhimurium cells irradiated at different times upon photo-Fenton conditions. These findings might suggest for the first time that photo-Fenton process at pH 5.5 could induce viable but nonculturable state (VBNC) on waterborne S. typhimurium and that probably sugar metabolism damage could activate the VBNC state.展开更多
Recent reports suggest that aging is not solely a physiological process in living beings;instead, it should be considered a pathological process or disease(Amorim et al., 2022). Consequently, this process involves a w...Recent reports suggest that aging is not solely a physiological process in living beings;instead, it should be considered a pathological process or disease(Amorim et al., 2022). Consequently, this process involves a wide range of factors, spanning from genetic to environmental factors, and even includes the gut microbiome(GM)(Mayer et al., 2022). All these processes coincide at some point in the inflammatory process, oxidative stress, and apoptosis, at different degrees in various organs and systems that constitute a living organism(Mayer et al., 2022;AguilarHernández et al., 2023).展开更多
Sinter is the core raw material for blast furnaces.Flue pressure,which is an important state parameter,affects sinter quality.In this paper,flue pressure prediction and optimization were studied based on the shapley a...Sinter is the core raw material for blast furnaces.Flue pressure,which is an important state parameter,affects sinter quality.In this paper,flue pressure prediction and optimization were studied based on the shapley additive explanation(SHAP)to predict the flue pressure and take targeted adjustment measures.First,the sintering process data were collected and processed.A flue pressure prediction model was then constructed after comparing different feature selection methods and model algorithms using SHAP+extremely random-ized trees(ET).The prediction accuracy of the model within the error range of±0.25 kPa was 92.63%.SHAP analysis was employed to improve the interpretability of the prediction model.The effects of various sintering operation parameters on flue pressure,the relation-ship between the numerical range of key operation parameters and flue pressure,the effect of operation parameter combinations on flue pressure,and the prediction process of the flue pressure prediction model on a single sample were analyzed.A flue pressure optimization module was also constructed and analyzed when the prediction satisfied the judgment conditions.The operating parameter combination was then pushed.The flue pressure was increased by 5.87%during the verification process,achieving a good optimization effect.展开更多
Recently published in Joule,Feng Liu and colleagues from Shanghai Jiaotong University reported a record-breaking 20.8%power conversion efficiency in organic solar cells(OSCs)with an interpenetrating fibril network act...Recently published in Joule,Feng Liu and colleagues from Shanghai Jiaotong University reported a record-breaking 20.8%power conversion efficiency in organic solar cells(OSCs)with an interpenetrating fibril network active layer morphology,featuring a bulk p-in structure and proper vertical segregation achieved through additive-assisted layer-by-layer deposition.This optimized hierarchical gradient fibrillar morphology and optical management synergistically facilitates exciton diffusion,reduces recombination losses,and enhances light capture capability.This approach not only offers a solution to achieving high-efficiency devices but also demonstrates the potential for commercial applications of OSCs.展开更多
Thin walls of an AZ91 magnesium alloy with fine equiaxed grains were fabricated via cold arc-based wire arc additive manufacturing(CA-WAAM),and the droplet transfer behaviours,microstructures,and mechanical properties...Thin walls of an AZ91 magnesium alloy with fine equiaxed grains were fabricated via cold arc-based wire arc additive manufacturing(CA-WAAM),and the droplet transfer behaviours,microstructures,and mechanical properties were investigated.The results showed that the cold arc process reduced splashing at the moment of liquid bridge breakage and effectively shortened the droplet transfer period.The microstructures of the deposited samples exhibited layered characteristics with alternating distributions of coarse and fine grains.During layer-by-layer deposition,the β-phase precipitated and grew preferentially along grain boundaries,while the fineη-Al_(8)Mn_(5)phase was dispersed in the α-Mg matrix.The mechanical properties of the CA-WAAM deposited sample showed isotropic characteristics.The ultimate tensile strength and elongation in the building direction(BD)were 282.7 MPa and 14.2%,respectively.The microhardness values of the deposited parts were relatively uniform,with an average value of HV 69.6.展开更多
Landslide dams,as frequent natural hazards,pose significant risks to human lives,property,and ecological environments.The grading characteristics and density of dam materials play a crucial role in determining the sta...Landslide dams,as frequent natural hazards,pose significant risks to human lives,property,and ecological environments.The grading characteristics and density of dam materials play a crucial role in determining the stability of landslide dams and the potential for dam breaches.To explore the failure mechanisms and evolutionary processes of landslide dams with varying soil properties,this study conducted a series of flume experiments,considering different grain compositions and material densities.The results demonstrated that grading characteristics significantly influence landslide dam stability,affecting failure patterns,breach processes,and final breach morphologies.Fine-graded materials exhibited a sequence of surface erosion,head-cut erosion,and subsequent surface erosion during the breach process,while well-graded materials typically experienced head-cut erosion followed by surface erosion.In coarse-graded dams,the high permeability of coarse particles allowed the dam to remain stable,as inflows matched outflows.The dam breach model experiments also showed that increasing material density effectively delayed the breach and reduced peak breach flow discharge.Furthermore,higher fine particle content led to a reduction in the residual dam height and the base slope of the final breach profile,although the relationship between peak breach discharge and the content of fine and coarse particles was nonlinear.To better understand breach morphology evolution under different soil characteristics and hydraulic conditions,three key points were identified—erosion point,control point,and scouring point.This study,by examining the evolution of failure patterns,breach processes,and breach flow discharges under various grading and density conditions,offers valuable insights into the mechanisms behind landslide dam failures.展开更多
This study aims to enhance the digital drilling process monitoring(DPM)or monitoring while drilling(MWD)technique,which is a widely recognized method in geological exploration for evaluating rock mass quality.First,ro...This study aims to enhance the digital drilling process monitoring(DPM)or monitoring while drilling(MWD)technique,which is a widely recognized method in geological exploration for evaluating rock mass quality.First,robust displacement and torque measurement facilities for rotary-core drilling are discussed.The conventional cable encoder for displacement measurement is replaced with a magnetostrictive displacement sensor,which is more reliable in harsh field drilling environments.This enables the measurement of the bit position with an accuracy of<1 mm.Most importantly,this new instrument is proven to be successful in improving the detection of structural discontinuities with thicknesses>1 mm.In addition,by measuring the electric current of the driving motor,the torque applied to the bit is conveniently and accurately converted.These innovations ensure high-quality data collection for DPM practices.Second,two indices derived from DPM are proposed to quantitatively describe rock mass quality.The specific energy index(SEI)and specific penetration index(SPI)are based on the principles of energy conservation and Mohr-Coulomb failure criterion,respectively.Extensive field tests conducted in a dam grouting area confirm a linear relationship between the thrust force and penetration per rotation,and between the torque and penetration per rotation.The correlation ratios of the related regressions are typically>0.9.These two indices allow for the quantitative interpretation of DPM data into rock mechanics characteristics,such as uniaxial compressive strength,rock quality designation(RQD),and rock mass permeability,eliminating the need for subjective judgment normally involved in the currently used rock mass quality rating approaches.展开更多
Spiral bevel gears are critical transmission components,and are widely used in the aerospace field.This paper proposes a new multi-DOF envelope forming process for fabricating spiral bevel gears.Firstly,the multi-DOF ...Spiral bevel gears are critical transmission components,and are widely used in the aerospace field.This paper proposes a new multi-DOF envelope forming process for fabricating spiral bevel gears.Firstly,the multi-DOF envelope forming principle of spiral bevel gears is proposed.Secondly,the design methods for the envelope tool geometry and movement are proposed based on the envelope geometry and movement relationships.Thirdly,the metal flow and tooth filling laws are revealed through 3D FE simulation of the multi-DOF envelope forming process of a typical spiral bevel gear.Fourthly,a new method for separating the envelope tool and the formed spiral bevel gear with back taper tooth is proposed to avoid their interference.Finally,experiments on multi-DOF envelope forming of this typical spiral bevel gear are conducted using new heavy load multi-DOF envelope forming equipment.The simulation and experimental results show the feasibility of the proposed multi-DOF envelope forming process for fabricating spiral bevel gears with back taper tooth and the corresponding process design methods.展开更多
The big-tapered profiled ring disk is a key component of engines for rockets and missiles.A new forming technology,as called spinning-rolling process,has been proposed previously for the high performance,high efficien...The big-tapered profiled ring disk is a key component of engines for rockets and missiles.A new forming technology,as called spinning-rolling process,has been proposed previously for the high performance,high efficiency and low-cost manufacturing of the component.Blank design is the key part of plastic forming process design.For spinning-rolling process,the shape and size of the blank play a crucial role in process stability,deformation behavior and dimensional accuracy.So this work proposes a blank design method to determine the geometry structure and sizes of the blank.The mathematical model for calculating the blank size has been deduced based on volume conservation and neutral layer length invariance principle.The FE simulation and corresponding trial production of an actual big-tapered profiled ring disk show that the proposed blank design method is applicative.In order to obtain a preferred blank,the influence rules of blank size determined by different deformation degrees(rolling ratio k)on the spinning-rolling process are revealed by comprehensive FE simulations.Overall considering the process stability,circularity of the deformed ring disk and forming forces,a reasonable range of deformation degree(rolling ratio k)is recommended for the blank design of the new spinning-rolling process.展开更多
Both citrate and hypophosphite in aqueous solution were degraded by advanced oxidation processes (Fe^2+/H2O2, UV/Fe^2+/H2O2, and electrolysis/Fe^2+/H2O2) in this study. Comparison of these techniques in oxidation...Both citrate and hypophosphite in aqueous solution were degraded by advanced oxidation processes (Fe^2+/H2O2, UV/Fe^2+/H2O2, and electrolysis/Fe^2+/H2O2) in this study. Comparison of these techniques in oxidation efficiency was undertaken. It was found that Fenton process could not completely degrade citrate in the presence of hypophosphite since it caused a series inhibition. Therefore, UV light (photo-Fenton) or electron current (electro-Fenton) was applied to improve the degradation efficiency of the Fenton process. Results showed that both photo-Fenton and electro-Fenton processes could overcome the inhibition of hypophosphite, especially the electro-Fenton.展开更多
The heterogeneous photo-Fenton reaction is an effective technique in combating organic contaminants for both soil and water remediation,and extensive studies have focused on enhancing its efficiency and reducing its c...The heterogeneous photo-Fenton reaction is an effective technique in combating organic contaminants for both soil and water remediation,and extensive studies have focused on enhancing its efficiency and reducing its costs.In this work,we developed novel photoFenton catalysts by simply milling commercially available TiO_2(P25)with Schwertmannite(Sh),a natural iron-oxyhydroxysulfate nanomineral.We expect that the photo-generated electrons from TiO_2could continuously migrate to Sh,which then could enhance the separation of electron-hole pairs on TiO_2and accelerate the reduction of Fe(III)to Fe(II)on Sh,leading to high degradation efficiency of the target organic contaminants.SEM and TEM results showed the distribution of TiO_2on Sh surface for the nanocomposites(TiO_2/Sh).Under simulated sunlight irradiation,the much higher content of Fe(II)was determined on TiO_2/Sh than on Sh via a common method in the iron ore,and the consumption of H_2O_2and the production of·OH were more significant in the TiO_2/Sh system than those in the TiO_2and Sh systems.These results well support our hypothesis that the photo-generated electrons could migrate from TiO_2to Sh on the composites,and can also explain the much higher degradation efficiency of Rhodamine B(RhB)in the TiO_2/Sh system.Besides,TiO_2/Sh had lower Fe dissolution as compared with Sh,and retained high catalytic stability after four repeated cycles.Above merits of the TiO_2/Sh composites,in combining with their simple synthesis method and low-cost property,indicated that they should have promising applications as heterogeneous photo-Fenton catalysts.展开更多
The decolorization of Reactive Yellow 86 (RY 86), one of reactive azo dyes, was investigated in the presence of Fenton reagent under solar light irradiation. The decolorization rate was strongly influenced by pH, in...The decolorization of Reactive Yellow 86 (RY 86), one of reactive azo dyes, was investigated in the presence of Fenton reagent under solar light irradiation. The decolorization rate was strongly influenced by pH, initial concentrations of H202 and Fe(II), and so on. An initial concentration of 40 mg/L was decolored more than 90% after 20 min under optimum conditions. The activation energy of the solar photo-Fenton reaction was 1.50 kJ/mol for RY 86 in the temperature range of 10-60℃. In the kinetic study, the rate constant of RY 86 with OH- radicals could be estimated to be 1.7 × 10^10 L/(mol.sec). The decolorization efficiency of RY 86 under solar light irradiation was comparable to the artificial light irradiation. The decrease of TOC as a result of mineralization of RY 86 was observed during photo-Fenton process. The rate of RY 86 mineralization was about 83% under UV irradiation after 24 hr. The formation of chloride, sulfate, nitrate and ammonium ions as end-products was observed during the photocatalytic process. The decomposition of RY 86 gave two kinds of intermediate products. The degradation mechanism of RY 86 was proposed on the base of the identified intermediates.展开更多
MIL-101(Fe)-NH_(2)@Al_(2)O_(3)(MA)catalysts were successfully synthesized by reactive seeding(RS)method onα-Al_(2)O_(3)substrate,which demonstrated excellent photo-Fenton degradation performance toward fluoroquinolon...MIL-101(Fe)-NH_(2)@Al_(2)O_(3)(MA)catalysts were successfully synthesized by reactive seeding(RS)method onα-Al_(2)O_(3)substrate,which demonstrated excellent photo-Fenton degradation performance toward fluoroquinolone antibiotics(i.e.,norfloxacin,ciprofloxacin,and enrofloxacin).The structure and morphology of the obtained MA were characterized by transmission electron microscopy(TEM),high-resolution transmission electron microscopy(HRTEM),atomic force microscope(AFM).The as-prepared MA could accomplish>90%of norfloxacin degradation efficiency for 10 cycles’photo-Fenton processes,owing to its excellent chemical and water stability.In addition,the effects of operational factors including H_(2)O_(2)concentration,foreign ions,and pH on the photo-Fenton degradation of norfloxacin over MA were clarified.The ESR spectra further document that^(•)O_(2)^(−),1O_(2)and•OH radicals are prominent in the decomposition process of antibiotic molecules.Finally,the plausible photo-Fenton norfloxacin degradation mechanisms were proposed and verified.展开更多
The sensory perception of food is a dynamic process,which is closely related to the release of flavor substances during oral processing.It’s not only affected by the food material,but also subjected to the individual...The sensory perception of food is a dynamic process,which is closely related to the release of flavor substances during oral processing.It’s not only affected by the food material,but also subjected to the individual oral environment.To explore the oral processing characteristics of soft-boiled chicken,the sensory properties,texture,particle size,viscosity,characteristic values of electronic nose and tongue of different chicken samples were investigated.The correlation analysis showed that the physical characteristics especially the cohesiveness,springiness,resilience of the sample determined oral processing behavior.The addition of chicken skin played a role in lubrication during oral processing.The particle size of the bolus was heightened at the early stage,and the fluidity was enhanced in the end,which reduced the chewing time to the swallowing point and raised the aromatic compounds signal of electronic nose.But the effect of chicken skin on chicken thigh with relatively high fat content,was opposite in electronic nose,which had a certain masking effect on the perception of umami and sweet taste.In conclusion,fat played a critical role in chicken oral processing and chicken thigh had obvious advantages in comprehensive evaluation of soft-boiled chicken,which was more popular among people.展开更多
Gas hydrate drilling expeditions in the Pearl River Mouth Basin,South China Sea,have identified concentrated gas hydrates with variable thickness.Moreover,free gas and the coexistence of gas hydrate and free gas have ...Gas hydrate drilling expeditions in the Pearl River Mouth Basin,South China Sea,have identified concentrated gas hydrates with variable thickness.Moreover,free gas and the coexistence of gas hydrate and free gas have been confirmed by logging,coring,and production tests in the foraminifera-rich silty sediments with complex bottom-simulating reflectors(BSRs).The broad-band processing is conducted on conventional three-dimensional(3D)seismic data to improve the image and detection accuracy of gas hydratebearing layers and delineate the saturation and thickness of gas hydrate-and free gas-bearing sediments.Several geophysical attributes extracted along the base of the gas hydrate stability zone are used to demonstrate the variable distribution and the controlling factors for the differential enrichment of gas hydrate.The inverted gas hydrate saturation at the production zone is over 40% with a thickness of 90 m,showing the interbedded distribution with different boundaries between gas hydrate-and free gas-bearing layers.However,the gas hydrate saturation value at the adjacent canyon is 70%,with 30-m-thick patches and linear features.The lithological and fault controls on gas hydrate and free gas distributions are demonstrated by tracing each gas hydrate-bearing layer.Moreover,the BSR depths based on broad-band reprocessed 3D seismic data not only exhibit variations due to small-scale topographic changes caused by seafloor sedimentation and erosion but also show the upward shift of BSR and the blocky distribution of the coexistence of gas hydrate and free gas in the Pearl River Mouth Basin.展开更多
文摘Industrial effluents from textile, tannery or printing activities often have a significant pollutant load composed of dyes that are difficult to biodegrade. These dyes pose a threat to the environment. To overcome this problem, various processes have been developed to eliminate these dyes in wastewater before their release into nature. Conventional biological or physical processes most often prove to be ineffective and expensive. It is therefore necessary to resort to other processes such as advanced oxidation processes (POA). This work therefore focuses on the study of the influence of clay in the degradation of Methylene Blue by the photo-Fenton process which is one of the advanced oxidation processes (POA), with the source of irradiation, natural light. To do this, two clays from Côte d’Ivoire referenced AB and Aga were the subject of a physicochemical and mineralogical characterization. The results showed that Aga clay is composed of 75.43% quartz, 12.72% kaolinite, 8.75% illite and 3.12% goethite and AB clay consists of 61, 36% kaolinite, 28.6% quartz and 10.10% illite. Under natural light irradiation the optimal amounts of Fenton reagents (iron: 10 mg;H2O2: 0.1 mL) were determined. Finally, the addition of clay to the photo-Fenton process made it possible to improve the degradation of the pollutant (Methylene Blue). Indeed, the yield increased from 92% for the photo-Fenton process to 98.43% with the addition of AB clay and 98.13% for the addition of Aga clay. The results of the degradation kinetics clearly show that the degradation follows the pseudo-second order kinetics with correlation coefficients greater than 0.99.
文摘In this work, the degradation of 2-chloro-4,6-diamino-1,3,5-triazine in aqueous solutions by photo-Fenton process has been investigated. The preliminary results have shown that the degradation of 2-chloro-4,6-diamino-1,3,5-triazine by photo-Fenton process is more rapid and more effective than Fenton and UV/H2O2 processes. The effects of certain experimental parameters on kinetics and efficiency of the degradation of 2-chloro-4,6,-diamino-1,3,5-triazine by photo-Fenton process, have been evaluated. Under optimal conditions, photo-Fenton process achieved more than 90% of chloride release and about 30% of nitrate formation. The results of total organic carbon (TOC) and total Kjeldahl nitrogen (TKN) analyses have shown that no carbon dioxide and ammonia are formed during photo-Fenton treatment of aqueous solutions containing 40 mg/L triazine. These results indicate that only substituent groups of triazine ring are released;however, nitrogen atoms of triazine ring remain unaffected. A simple mechanism of degradation of 2-chloro-4,6-diamino-1,3,5-triazine has been proposed. The degradation starts by a rapid release of chlorine atoms as chloride ions to form 2-hydroxy-4,6-diamino-1,3,5-triazine. The amino groups of 2-hydroxy-4,6-diamino-1,3,5-triazine undergo are oxidized into nitro groups by hydroxyl radicals to form 2-hydroxy-4,6-dinitro-1,3,5-triazine which undergoes a slow release of nitro groups and their substitution with hydroxyl groups to form cyanuric acid and nitrate ions. The degradation of cyanuric acid by photo-Fenton process has also been investigated. The results of TOC and TKN analyzes show that no carbon dioxide is formed during the treatment.
文摘The present work evaluated the use of photo-Fenton process for the treatment of kraft pulp mill effluent. The photo-Fenton best operating conditions, such as pH, concentration, and H2O2: Fe2+ ratio were evaluated. The efficiency of the treatment was measured by COD (chemical oxygen demand) removal. The results showed that the optimum pH for the photo-Fenton process was equal to 3. The increase in H2O2 application resulted in an efficiency increase of the photo-Fenton process, although this was not a directly proportional relation. For most cases, the H2O2: Fe2+ proportion of 100:1 yielded the best results for COD removal. Solar radiation was more efficient than artificial UV to the COD removal. During the treatment the organic matter of the effluent was more oxidized than mineralized, showing a higher removal of COD than BOD (biochemical oxygen demand) and TOC (total organic carbon), respectively. So, photo-Fenton process increased the BOD/ COD ration but decreased the BOD/TOC ratio.
基金MincyT(Argentina)and COLCIENCIAS(Colombia)for their support to the project ECOS-NORD(CO/10/04).
文摘Culturability and viability techniques such as plate count on solid agar (PC), Most Probable Number (MPN) and Direct Viable Count-Fluorescence in Situ Hybridation (DVC FISH) were used to study the inactivation of Salmonella typhimurium by photo-Fenton process at pH 5.5. In the presence of only simulated solar irradiation (500 W·m-2), S. typhimurim showed that both culturability measured by MPN and viability (measured by DVC FISH) underwent just a slight decreasing of 2 and 1 log respectively after 240 min of light exposition while culturability measured by PC did not show any change. Results after 48 h of dark conditions did not reveal re-growth. However, when experiment was carried out in the presence of 2 mg L-1 of Fe3+ and 20 mg L-1 of H2O2 and pH 5.5, culturability was strongly affected after 240 min of simulated solar irradiation;nevertheless, viability was only slightly altered (~1 log). During dark period of 48 h changes on culturability and viability were not observed. On the other hand, it was also found that sugar metabolism was affected rather the amino-acids in S. typhimurium cells irradiated at different times upon photo-Fenton conditions. These findings might suggest for the first time that photo-Fenton process at pH 5.5 could induce viable but nonculturable state (VBNC) on waterborne S. typhimurium and that probably sugar metabolism damage could activate the VBNC state.
基金funded by CONAHCYT grant(252808)to GFCONAHCYT’s“Estancias Posdoctorales por México”program(662350)to HTB。
文摘Recent reports suggest that aging is not solely a physiological process in living beings;instead, it should be considered a pathological process or disease(Amorim et al., 2022). Consequently, this process involves a wide range of factors, spanning from genetic to environmental factors, and even includes the gut microbiome(GM)(Mayer et al., 2022). All these processes coincide at some point in the inflammatory process, oxidative stress, and apoptosis, at different degrees in various organs and systems that constitute a living organism(Mayer et al., 2022;AguilarHernández et al., 2023).
基金supported by the General Program of the National Natural Science Foundation of China(No.52274326)the China Baowu Low Carbon Metallurgy Innovation Foundation(No.BWLCF202109)the Seventh Batch of Ten Thousand Talents Plan of China(No.ZX20220553).
文摘Sinter is the core raw material for blast furnaces.Flue pressure,which is an important state parameter,affects sinter quality.In this paper,flue pressure prediction and optimization were studied based on the shapley additive explanation(SHAP)to predict the flue pressure and take targeted adjustment measures.First,the sintering process data were collected and processed.A flue pressure prediction model was then constructed after comparing different feature selection methods and model algorithms using SHAP+extremely random-ized trees(ET).The prediction accuracy of the model within the error range of±0.25 kPa was 92.63%.SHAP analysis was employed to improve the interpretability of the prediction model.The effects of various sintering operation parameters on flue pressure,the relation-ship between the numerical range of key operation parameters and flue pressure,the effect of operation parameter combinations on flue pressure,and the prediction process of the flue pressure prediction model on a single sample were analyzed.A flue pressure optimization module was also constructed and analyzed when the prediction satisfied the judgment conditions.The operating parameter combination was then pushed.The flue pressure was increased by 5.87%during the verification process,achieving a good optimization effect.
基金Technology Development Program of Jilin Province(YDZJ202201ZYTS640)the National Key Research and Development Program of China(2022YFB4200400)funded by MOST+4 种基金the National Natural Science Foundation of China(52172048 and 52103221)Shandong Provincial Natural Science Foundation(ZR2021QB024 and ZR2021ZD06)Guangdong Basic and Applied Basic Research Foundation(2023A1515012323,2023A1515010943,and 2024A1515010023)the Qingdao New Energy Shandong Laboratory open Project(QNESL OP 202309)the Fundamental Research Funds of Shandong University.
文摘Recently published in Joule,Feng Liu and colleagues from Shanghai Jiaotong University reported a record-breaking 20.8%power conversion efficiency in organic solar cells(OSCs)with an interpenetrating fibril network active layer morphology,featuring a bulk p-in structure and proper vertical segregation achieved through additive-assisted layer-by-layer deposition.This optimized hierarchical gradient fibrillar morphology and optical management synergistically facilitates exciton diffusion,reduces recombination losses,and enhances light capture capability.This approach not only offers a solution to achieving high-efficiency devices but also demonstrates the potential for commercial applications of OSCs.
基金supported by the National Natural Science Foundation of China(No.51805265)the Fundamental Research Funds for the Central Universities,China(No.30922010921).
文摘Thin walls of an AZ91 magnesium alloy with fine equiaxed grains were fabricated via cold arc-based wire arc additive manufacturing(CA-WAAM),and the droplet transfer behaviours,microstructures,and mechanical properties were investigated.The results showed that the cold arc process reduced splashing at the moment of liquid bridge breakage and effectively shortened the droplet transfer period.The microstructures of the deposited samples exhibited layered characteristics with alternating distributions of coarse and fine grains.During layer-by-layer deposition,the β-phase precipitated and grew preferentially along grain boundaries,while the fineη-Al_(8)Mn_(5)phase was dispersed in the α-Mg matrix.The mechanical properties of the CA-WAAM deposited sample showed isotropic characteristics.The ultimate tensile strength and elongation in the building direction(BD)were 282.7 MPa and 14.2%,respectively.The microhardness values of the deposited parts were relatively uniform,with an average value of HV 69.6.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.U22A20602,U2040221,and 42207228)the Sichuan Science and Technology Program(2022NSFSC1060)the Fundamental Research Funds for Central Public Research Institutes(Grant No.Y324006)。
文摘Landslide dams,as frequent natural hazards,pose significant risks to human lives,property,and ecological environments.The grading characteristics and density of dam materials play a crucial role in determining the stability of landslide dams and the potential for dam breaches.To explore the failure mechanisms and evolutionary processes of landslide dams with varying soil properties,this study conducted a series of flume experiments,considering different grain compositions and material densities.The results demonstrated that grading characteristics significantly influence landslide dam stability,affecting failure patterns,breach processes,and final breach morphologies.Fine-graded materials exhibited a sequence of surface erosion,head-cut erosion,and subsequent surface erosion during the breach process,while well-graded materials typically experienced head-cut erosion followed by surface erosion.In coarse-graded dams,the high permeability of coarse particles allowed the dam to remain stable,as inflows matched outflows.The dam breach model experiments also showed that increasing material density effectively delayed the breach and reduced peak breach flow discharge.Furthermore,higher fine particle content led to a reduction in the residual dam height and the base slope of the final breach profile,although the relationship between peak breach discharge and the content of fine and coarse particles was nonlinear.To better understand breach morphology evolution under different soil characteristics and hydraulic conditions,three key points were identified—erosion point,control point,and scouring point.This study,by examining the evolution of failure patterns,breach processes,and breach flow discharges under various grading and density conditions,offers valuable insights into the mechanisms behind landslide dam failures.
基金financially supported by the National Natural Science Foundation of China(Grant No.52079150)Science and Technology Major Project of the Xizang Autonomous Region of China(XZ202201ZD0003G)Water Conservancy Technology Demonstration Project(SF-202404).
文摘This study aims to enhance the digital drilling process monitoring(DPM)or monitoring while drilling(MWD)technique,which is a widely recognized method in geological exploration for evaluating rock mass quality.First,robust displacement and torque measurement facilities for rotary-core drilling are discussed.The conventional cable encoder for displacement measurement is replaced with a magnetostrictive displacement sensor,which is more reliable in harsh field drilling environments.This enables the measurement of the bit position with an accuracy of<1 mm.Most importantly,this new instrument is proven to be successful in improving the detection of structural discontinuities with thicknesses>1 mm.In addition,by measuring the electric current of the driving motor,the torque applied to the bit is conveniently and accurately converted.These innovations ensure high-quality data collection for DPM practices.Second,two indices derived from DPM are proposed to quantitatively describe rock mass quality.The specific energy index(SEI)and specific penetration index(SPI)are based on the principles of energy conservation and Mohr-Coulomb failure criterion,respectively.Extensive field tests conducted in a dam grouting area confirm a linear relationship between the thrust force and penetration per rotation,and between the torque and penetration per rotation.The correlation ratios of the related regressions are typically>0.9.These two indices allow for the quantitative interpretation of DPM data into rock mechanics characteristics,such as uniaxial compressive strength,rock quality designation(RQD),and rock mass permeability,eliminating the need for subjective judgment normally involved in the currently used rock mass quality rating approaches.
基金the National Science and Technology Major Project of China(No.2019-Ⅶ0017e0158)the National Natural Science Foundation of China(No.U21A20131)+1 种基金the Industry-University Research Cooperation Project,China(No.HFZL2020CXY025)the National Key Laboratory of Science and Technology on Helicopter Transmission,China(No.HTL-O-21G05)。
文摘Spiral bevel gears are critical transmission components,and are widely used in the aerospace field.This paper proposes a new multi-DOF envelope forming process for fabricating spiral bevel gears.Firstly,the multi-DOF envelope forming principle of spiral bevel gears is proposed.Secondly,the design methods for the envelope tool geometry and movement are proposed based on the envelope geometry and movement relationships.Thirdly,the metal flow and tooth filling laws are revealed through 3D FE simulation of the multi-DOF envelope forming process of a typical spiral bevel gear.Fourthly,a new method for separating the envelope tool and the formed spiral bevel gear with back taper tooth is proposed to avoid their interference.Finally,experiments on multi-DOF envelope forming of this typical spiral bevel gear are conducted using new heavy load multi-DOF envelope forming equipment.The simulation and experimental results show the feasibility of the proposed multi-DOF envelope forming process for fabricating spiral bevel gears with back taper tooth and the corresponding process design methods.
基金the National Natural Science Foundation of China(No.52275378)the National Key Laboratory for Precision Hot Processing of Metals(6142909200208)。
文摘The big-tapered profiled ring disk is a key component of engines for rockets and missiles.A new forming technology,as called spinning-rolling process,has been proposed previously for the high performance,high efficiency and low-cost manufacturing of the component.Blank design is the key part of plastic forming process design.For spinning-rolling process,the shape and size of the blank play a crucial role in process stability,deformation behavior and dimensional accuracy.So this work proposes a blank design method to determine the geometry structure and sizes of the blank.The mathematical model for calculating the blank size has been deduced based on volume conservation and neutral layer length invariance principle.The FE simulation and corresponding trial production of an actual big-tapered profiled ring disk show that the proposed blank design method is applicative.In order to obtain a preferred blank,the influence rules of blank size determined by different deformation degrees(rolling ratio k)on the spinning-rolling process are revealed by comprehensive FE simulations.Overall considering the process stability,circularity of the deformed ring disk and forming forces,a reasonable range of deformation degree(rolling ratio k)is recommended for the blank design of the new spinning-rolling process.
基金The authors thank the "National" Science Council, Taiwan, China for financially supporting (No. NSC95- 2211-E-006-032).
文摘Both citrate and hypophosphite in aqueous solution were degraded by advanced oxidation processes (Fe^2+/H2O2, UV/Fe^2+/H2O2, and electrolysis/Fe^2+/H2O2) in this study. Comparison of these techniques in oxidation efficiency was undertaken. It was found that Fenton process could not completely degrade citrate in the presence of hypophosphite since it caused a series inhibition. Therefore, UV light (photo-Fenton) or electron current (electro-Fenton) was applied to improve the degradation efficiency of the Fenton process. Results showed that both photo-Fenton and electro-Fenton processes could overcome the inhibition of hypophosphite, especially the electro-Fenton.
基金financially supported by the National Natural Science Foundation of China (No. 41572031)the Science and Technology Planning Project of Guangdong Province, China (No. 2017B030314175)+1 种基金the National Program for Support of Top-notch Young ProfessionalsChina scholarship council
文摘The heterogeneous photo-Fenton reaction is an effective technique in combating organic contaminants for both soil and water remediation,and extensive studies have focused on enhancing its efficiency and reducing its costs.In this work,we developed novel photoFenton catalysts by simply milling commercially available TiO_2(P25)with Schwertmannite(Sh),a natural iron-oxyhydroxysulfate nanomineral.We expect that the photo-generated electrons from TiO_2could continuously migrate to Sh,which then could enhance the separation of electron-hole pairs on TiO_2and accelerate the reduction of Fe(III)to Fe(II)on Sh,leading to high degradation efficiency of the target organic contaminants.SEM and TEM results showed the distribution of TiO_2on Sh surface for the nanocomposites(TiO_2/Sh).Under simulated sunlight irradiation,the much higher content of Fe(II)was determined on TiO_2/Sh than on Sh via a common method in the iron ore,and the consumption of H_2O_2and the production of·OH were more significant in the TiO_2/Sh system than those in the TiO_2and Sh systems.These results well support our hypothesis that the photo-generated electrons could migrate from TiO_2to Sh on the composites,and can also explain the much higher degradation efficiency of Rhodamine B(RhB)in the TiO_2/Sh system.Besides,TiO_2/Sh had lower Fe dissolution as compared with Sh,and retained high catalytic stability after four repeated cycles.Above merits of the TiO_2/Sh composites,in combining with their simple synthesis method and low-cost property,indicated that they should have promising applications as heterogeneous photo-Fenton catalysts.
基金supported by the Ministry of Education,Culture,Sports,Science,and Technology of Japan
文摘The decolorization of Reactive Yellow 86 (RY 86), one of reactive azo dyes, was investigated in the presence of Fenton reagent under solar light irradiation. The decolorization rate was strongly influenced by pH, initial concentrations of H202 and Fe(II), and so on. An initial concentration of 40 mg/L was decolored more than 90% after 20 min under optimum conditions. The activation energy of the solar photo-Fenton reaction was 1.50 kJ/mol for RY 86 in the temperature range of 10-60℃. In the kinetic study, the rate constant of RY 86 with OH- radicals could be estimated to be 1.7 × 10^10 L/(mol.sec). The decolorization efficiency of RY 86 under solar light irradiation was comparable to the artificial light irradiation. The decrease of TOC as a result of mineralization of RY 86 was observed during photo-Fenton process. The rate of RY 86 mineralization was about 83% under UV irradiation after 24 hr. The formation of chloride, sulfate, nitrate and ammonium ions as end-products was observed during the photocatalytic process. The decomposition of RY 86 gave two kinds of intermediate products. The degradation mechanism of RY 86 was proposed on the base of the identified intermediates.
基金supported by National Natural Science Foundation of China(No.22176012)Beijing Natural Science Foundation(No.8202016)。
文摘MIL-101(Fe)-NH_(2)@Al_(2)O_(3)(MA)catalysts were successfully synthesized by reactive seeding(RS)method onα-Al_(2)O_(3)substrate,which demonstrated excellent photo-Fenton degradation performance toward fluoroquinolone antibiotics(i.e.,norfloxacin,ciprofloxacin,and enrofloxacin).The structure and morphology of the obtained MA were characterized by transmission electron microscopy(TEM),high-resolution transmission electron microscopy(HRTEM),atomic force microscope(AFM).The as-prepared MA could accomplish>90%of norfloxacin degradation efficiency for 10 cycles’photo-Fenton processes,owing to its excellent chemical and water stability.In addition,the effects of operational factors including H_(2)O_(2)concentration,foreign ions,and pH on the photo-Fenton degradation of norfloxacin over MA were clarified.The ESR spectra further document that^(•)O_(2)^(−),1O_(2)and•OH radicals are prominent in the decomposition process of antibiotic molecules.Finally,the plausible photo-Fenton norfloxacin degradation mechanisms were proposed and verified.
基金supported by China Agriculture Research System of MOF and MARA(CARS-41)Wens Fifth Five R&D Major Project(WENS-2020-1-ZDZX-007)。
文摘The sensory perception of food is a dynamic process,which is closely related to the release of flavor substances during oral processing.It’s not only affected by the food material,but also subjected to the individual oral environment.To explore the oral processing characteristics of soft-boiled chicken,the sensory properties,texture,particle size,viscosity,characteristic values of electronic nose and tongue of different chicken samples were investigated.The correlation analysis showed that the physical characteristics especially the cohesiveness,springiness,resilience of the sample determined oral processing behavior.The addition of chicken skin played a role in lubrication during oral processing.The particle size of the bolus was heightened at the early stage,and the fluidity was enhanced in the end,which reduced the chewing time to the swallowing point and raised the aromatic compounds signal of electronic nose.But the effect of chicken skin on chicken thigh with relatively high fat content,was opposite in electronic nose,which had a certain masking effect on the perception of umami and sweet taste.In conclusion,fat played a critical role in chicken oral processing and chicken thigh had obvious advantages in comprehensive evaluation of soft-boiled chicken,which was more popular among people.
基金supported by the State Key Laboratory of Natural Gas Hydrate(No.2022-KFJJ-SHW)the National Natural Science Foundation of China(No.42376058)+2 种基金the International Science&Technology Cooperation Program of China(No.2023YFE0119900)the Hainan Province Key Research and Development Project(No.ZDYF2024GXJS002)the Research Start-Up Funds of Zhufeng Scholars Program.
文摘Gas hydrate drilling expeditions in the Pearl River Mouth Basin,South China Sea,have identified concentrated gas hydrates with variable thickness.Moreover,free gas and the coexistence of gas hydrate and free gas have been confirmed by logging,coring,and production tests in the foraminifera-rich silty sediments with complex bottom-simulating reflectors(BSRs).The broad-band processing is conducted on conventional three-dimensional(3D)seismic data to improve the image and detection accuracy of gas hydratebearing layers and delineate the saturation and thickness of gas hydrate-and free gas-bearing sediments.Several geophysical attributes extracted along the base of the gas hydrate stability zone are used to demonstrate the variable distribution and the controlling factors for the differential enrichment of gas hydrate.The inverted gas hydrate saturation at the production zone is over 40% with a thickness of 90 m,showing the interbedded distribution with different boundaries between gas hydrate-and free gas-bearing layers.However,the gas hydrate saturation value at the adjacent canyon is 70%,with 30-m-thick patches and linear features.The lithological and fault controls on gas hydrate and free gas distributions are demonstrated by tracing each gas hydrate-bearing layer.Moreover,the BSR depths based on broad-band reprocessed 3D seismic data not only exhibit variations due to small-scale topographic changes caused by seafloor sedimentation and erosion but also show the upward shift of BSR and the blocky distribution of the coexistence of gas hydrate and free gas in the Pearl River Mouth Basin.