To address the problems with catalytic degradation,such as poisoning and inactivation,a simple and efficient gas purging regeneration technique was developed for iron-based catalyst in-situ regeneration.Specifically,t...To address the problems with catalytic degradation,such as poisoning and inactivation,a simple and efficient gas purging regeneration technique was developed for iron-based catalyst in-situ regeneration.Specifically,the effects of carrier gas types,regeneration temperatures,and granular activated carbon(GAC)addition on iron-based catalyst regeneration were investigated.The Fe_(3)O_(4)/𝛾-Al_(2)O_(3) regenerated at 550°C with additional GAC and 15%water vapor exhibited the optimal degradation efficiency towards polychlorinated biphenyls(PCBs),with an increase from 41.2%to 93.5%,compared with non-regenerated Fe_(3)O_(4)/𝛾-Al_(2)O_(3).In addition,the 60-hour stability test revealed a well-recovered catalytic activity.During the Fe_(3)O_(4)/𝛾-Al_(2)O_(3) regeneration,the coke on the catalyst surface was oxidized and removed in the form of CO_(2),and meanwhile the oxidized Fe(III)was reduced into Fe(II)in the catalyst.This study provides a safe and efficient iron-based catalyst regeneration technology for PCB off-gas degradation and reveals the catalytic activity recovery mechanism during catalyst regeneration.展开更多
The discharge of micro-polluted water from sources such as agricultural runoff,urban stormwater,and treated effluents presents significant challenges to aquatic ecosystems.Constructed wetlands(CWs)have gained recog-ni...The discharge of micro-polluted water from sources such as agricultural runoff,urban stormwater,and treated effluents presents significant challenges to aquatic ecosystems.Constructed wetlands(CWs)have gained recog-nition as an eco-friendly solution for removing pollutants from various wastewater sources and are increasingly applied for micro-polluted water treatment.By reviewing 78 full-scale CW studies from Web of Science,it is summarized that the ranges of ammonium nitrogen(NH4+-N)concentrations in runoff,wastewater treatment plant effluent and polluted river were 0.1–6.6,0.3–12.3,and 0.2–41.1 mg/L,respectively.The ranges of ni-trate nitrogen concentrations were 0.2–14.2,0–5.7,and 0–2.6 mg/L,respectively.Removal efficiencies of CWs for micro-polluted water varied by CW types.The total nitrogen removal efficiencies for subsurface-flow CWs,free-water surface-flow CWs,and hybrid CWs ranged from 27.4%to 66.5%,16.8%to 89.8%,and 19.4%to 88.2%,respectively.The NH4+-N removal efficiencies ranged from 34.2%to 73.6%,38.4%to 89.4%and 13.5%to 94.2%,respectively.Additionally,other factors influencing contaminant removal efficiency such as hydraulic retention time,vegetation types,redox micro-environment and influent water quality were evaluated.Based on these findings,two strategies for improving the purification performance of CWs were proposed:the selection of incorporating electron donor substrates and the optimization of operation parameters.This paper serves as a synthesis of information to guide future research and full-scale CW applications in micro-polluted water treatment.展开更多
Environmental pollution,energy consumption,and greenhouse gas emissions are critical global issues.To address these challenges,optimizing skimmer coatings is a major step in commercializing cleaning oil stains.This re...Environmental pollution,energy consumption,and greenhouse gas emissions are critical global issues.To address these challenges,optimizing skimmer coatings is a major step in commercializing cleaning oil stains.This research presents a novel approach to creating and refining oil absorbent coatings,introducing a unique oil spill removal skimmer enhanced with a super hydrophobic polyaniline(PANI)nanofiber coating.The goal of this study was to improve oil absorption performance,increase the contact angle,lower drag,reduce energy consumption,achieve high desirability,and lower production costs.PANI treated with hydrochloric acid was a key focus as it resulted in higher porosity and smaller pore diameters,providing a larger surface area,which are crucial factors for boosting oil absorption and minimizing drag.To optimize optimal nanofiber morphology,PANI synthesized with methanesulfonic acid was first dedoped and then redoped with hydrochloric acid.After optimization,the most effective skimmer coating was achieved using a formulation consisting of 0.1%PANI,an ammonium persulfate/aniline ratio of 0.4,and an acid/aniline ratio of 9.689,along with redoped PANI nanofibers.The optimized skimmer exhibited a remarkable contact angle of 177.477°.The coating achieved drag reduction of 32%,oil absorption of 88.725%,a cost of$1.710,and a desirability rating of 78.5%.In this study,an optimized skimmer coat containing super hydrophobic coat-PANI nanofibers was fabricated.By enhancing contact angle and reducing drag,these coatings increased the skimmer performance by improving oil absorption and reducing fuel consumption.展开更多
Microglia are the macrophages that populate the brain parenchyma.Research in the past decades has identified them as both essential guardians of the brain and significant contributors to various neurological diseases....Microglia are the macrophages that populate the brain parenchyma.Research in the past decades has identified them as both essential guardians of the brain and significant contributors to various neurological diseases.A highly versatile cell type,microglia have been shown to fulfill a multitude of critical roles in the central nervous system,including facilitating neurogenesis and myelination,pruning synapses,removing debris and waste,modulating neuronal activity,supporting the blood-brain barrier,repairing tissue damage,and surveilling against microbial invasions under physiological conditions(Prinz et al.,2021;Paolicelli et al.,2022).展开更多
Laser-induced aerosols,predominantly submicron in size,pose significant environmental and health risks during the decommissioning of nuclear reactors.This study experimentally investigated the removal of laser-generat...Laser-induced aerosols,predominantly submicron in size,pose significant environmental and health risks during the decommissioning of nuclear reactors.This study experimentally investigated the removal of laser-generated aerosol particles using a water spray system integrated with an innovative system for pre-injecting electrically charged mist in our facility.To simulate aerosol generation in reactor decommissioning,a high-power laser was used to irradiate various materials(including stainless steel,carbon steel,and concrete),generating aerosol particles that were agglomerated with injected water mist and subsequently scavenged by water spray.Experimental results demonstrate enhanced aerosol removal via aerosol-mist agglomeration,with charged mist significantly improving particle capture by increasing wettability and size.The average improvements for the stainless steel,carbon steel,and concrete were 40%,44%,and 21%,respectively.The results of experiments using charged mist with different polarities(both positive and negative)and different surface coatings reveal that the dominant polarity of aerosols varies with the irradiated materials,influenced by their crystal structure and electron emission properties.Notably,surface coatings such as ZrO_(2)and CeO_(2)were found to possibly alter aerosol charging characteristics,thereby affecting aerosol removal efficiency with charged mist configurations.The innovative aerosol-mist agglomeration approach shows promise in mitigating radiation exposure,ensuring environmental safety,and reducing contaminated water during reactor dismantling.This study contributes critical knowledge for the development of advanced aerosol management strategies for nuclear reactor decommissioning.The understanding obtained in this work is also expected to be useful for various environmental and chemical engineering applications such as gas decontamination,air purification,and pollution control.展开更多
The remarkable ability of titanium alloys to preserve their superior physical and chemical characteristics when subjected to extreme conditions significantly enhances their importance in the aerospace,military,and med...The remarkable ability of titanium alloys to preserve their superior physical and chemical characteristics when subjected to extreme conditions significantly enhances their importance in the aerospace,military,and medical sectors.However,conventional machining of titanium alloys leads to elevated tool wear,development of surface defects,and reduced machining efficiency due to their low heat conductivity,and chemical affinity.These issues can be somewhat counteracted by integrating ultrasonic vibration in the conventional machining of titanium alloys and also enhance sustainability.This review article offers a holistic evaluation of the influence of ultrasonic vibration-assisted milling and turning on cutting forces,temperature,tool wear,and surface integrity,encompassing surface morphology,surface roughness,surface residual stress,surface hardness,and surface tribological properties during titanium alloys machining.Furthermore,it investigates the sustainability aspect that has not been previously examined.Studies on the performance of ultrasonic-assisted cutting revealed several advantages,including decreased cutting forces and cutting temperature,improved tool life,and a better-machined surface during machining.Consequently,the sustainability factor is improved due to minimized energy consumption and residual waste.In conclusion,the key challenges and future prospects in the ultrasonic-assisted cutting of titanium alloys are also discussed.This review article provides beneficial knowledge for manufactur-ers and researchers regarding ultrasonic vibration-assisted cutting of titanium alloy and will play an important role in achieving sustainability in the industry.展开更多
Nitrogen removal from domestic sewage is usually limited by insufficient carbon source and electron donor.An economical solid carbon source was developed by composition of polyvinyl alcohol,sodium alginate,and corncob...Nitrogen removal from domestic sewage is usually limited by insufficient carbon source and electron donor.An economical solid carbon source was developed by composition of polyvinyl alcohol,sodium alginate,and corncob,which was utilized as external carbon source in the anaerobic anoxic oxic(AAO)-biofilter for the treatment of low carbon-to-nitrogen ratio domestic sewage,and the nitrogen removal was remarkably improved from 63.2%to 96.5%.Furthermore,the effluent chemical oxygen demand maintained at 35 mg/L or even lower,and the total nitrogenwas reduced to less than 2mg/L.Metagenomic analysis demonstrated that the microbial communities responsible for potential denitrification and organic matter degradation in both AAO and the biofilter reactors were mainly composed of Proteobacteria and Bacteroides,respectively.The solid carbon source addition resulted in relatively high abundance of functional enzymes responsible for NO_(3)^(−)-N to NO_(2)^(−)-N con-version in both AAO and the biofilter reactors,thus enabled stable reaction.The carbon source addition during glycolysis primarily led to the increase of genes associated with the metabolic conversion of fructose 1.6P2 to glycerol-3P The reactor maintained high abun-dance of genes related to the tricarboxylic acid cycle,and then guaranteed efficient carbon metabolism.The results indicate that the composite carbon source is feasible for denitri-fication enhancement of AAO-biofilter,which contribute to the theoretical foundation for practical nitrogen removal application.展开更多
Current research primarily focuses on emerging organic pollutants,with limited attention to emerging inorganic pollutants (EIPs).However,due to advances in detection technology and the escalating environmental and hea...Current research primarily focuses on emerging organic pollutants,with limited attention to emerging inorganic pollutants (EIPs).However,due to advances in detection technology and the escalating environmental and health challenges posed by pollution,there is a growing interest in treating waters contaminated with EIPs.This paper explores biochar characteristics and modification methods,encompassing physical,chemical,and biological approaches for adsorbing EIPs.It offers a comprehensive review of research advancements in employing biochar for EIPs remediation in water,outlines the adsorption mechanisms of EIPs by biochar,and presents an environmental and economic analysis.It can be concluded that using biochar for the adsorption of EIPs in wastewater exhibits promising potential.Nonetheless,it is noteworthy that certain EIPs like Au(III),Rh(III),Ir(III),Ru(III),Os(III),Sc(III),and Y(III),have not been extensively investigated regarding their adsorption onto biochar.This comprehensive review will catalyze further inquiry into the biochar-based adsorption of EIPs,addressing current research deficiencies and advancing the practical implementation of biochar as a potent substrate for EIP removal from wastewater streams.展开更多
The mechanism of hydrate-based desalination is that water molecules would transfer to the hydrate phase during gas hydrate formation process,while the salt ions would be conversely concentrated in the unreacted saltwa...The mechanism of hydrate-based desalination is that water molecules would transfer to the hydrate phase during gas hydrate formation process,while the salt ions would be conversely concentrated in the unreacted saltwater.However,the salt concentration of hydrate decomposed water and the desalination degree of hydrate phase are still unclear.The biggest challenge is how to effectively separate the hydrate phase and the remaining unreacted salt water,and then decompose the hydrate phase to measure the salt concentration of hydrate melt water.This work developed an apparatus and pressure-driven filtration method to efficiently separate the hydrate phase and the remaining unreacted saltwater.On this basis,the single hydrate phase was obtained,then it was dissociated and the salt concentration of hydrate melt water was measured.The experimental results demonstrate that when the initial salt mass concentration is 0.3% to 8.0%,the salt removal efficiency for NaCl solution is 15.9% to 29.8%by forming CO_(2) hydrate,while for CaCl_(2) solution is 28.9%to 45.5%.The solute CaCl_(2) is easier to be removed than solute NaCl.In addition,the salt removal efficiency for forming CO_(2) hydrate is higher than that for forming methane hydrate.The multi-stage desalination can continuously decrease the salt concentration of hydrate dissociated water,and the salt removal efficiency per stage is around 20%.展开更多
Magnesium(Mg)alloys are widely used lightweight structural materials for automobiles and help reduce carbon emissions.However,their use increases the production of Mg alloy scrap,which is recycled at a much lower rate...Magnesium(Mg)alloys are widely used lightweight structural materials for automobiles and help reduce carbon emissions.However,their use increases the production of Mg alloy scrap,which is recycled at a much lower rate than aluminum,and its greater complexity poses challenges to existing recycling processes.Although vacuum distillation can be used to recycle Mg alloy scrap,this requires optimizing and maximizing metal recirculation,but there has been no thermodynamic analysis of this process.In this study,the feasibility and controllability of separating inclusions and 23 metal impurities were evaluated,and their distribution and removal limits were quantified.Thermodynamic analyses and experimental results showed that inclusions and impurity metals of separation coefficient lgβ_(i)≤-5,including Cu,Fe,Co,and Ni below 0.001 ppm,could be removed from the matrix.All Zn entered the recycled Mg,while impurities with-1<lgβ_(i)<-5 such as Li,Ca,and Mn severely affected the purity of the recycled Mg during the later stage of distillation.Therefore,an optimization strategy for vacuum distillation recycling:lower temperatures and higher system pressures for Zn separation in the early stage,and the early termination of the recovery process in the later stage or a continuous supply of raw melt can also prevent contamination during recycling.The alloying elements Al and Zn in Mg alloy scrap can be further recovered and purified by vacuum distillation when economically feasible,to maximize the recycling of metal resources.展开更多
Several studies have demonstrated that reintroducing crop straw to fields may intensify cadmium(Cd)contamination in agricultural soils.However,the specific effects of long-term straw management practices on Cd concent...Several studies have demonstrated that reintroducing crop straw to fields may intensify cadmium(Cd)contamination in agricultural soils.However,the specific effects of long-term straw management practices on Cd concentration and its bioavailability in soil-rice ecosystems remain unclear.In this context,to explore the influence of straw return(SR)and straw removal(NSR)on Cd accumulation in both soil and rice within a double-cropping system,we conducted a four-year field study.Our research study unveiled that NSR consistently decreased soil Cd concentration and its bioavailability by approximately 16.93%–27.30%and 8.23%–21.05%respectively across both study sites.Conversely,SR resulted in a substantial increase in soil Cd bioavailability,ranging from 38.64%–53.95%.Notably,compared to NSR,SR significantly increased total soil Cd by 5.47%–36.58%and increased Cd content in brown rice by 8.00%–100.24%.Remarkably,after four consecutive years of NSR,brown rice Cd concentration at the Changfeng site compiled with national safety standards(GB 2762–2022).Additionally,returning early rice strawsignificantly raised soil Cd bioavailability for the subsequent crop,more so than late rice straw did for the early rice the following year.The findings suggest that traditional double-cropping cultivation with straw removal can effectively mitigate Cd contamination risks in crops and farmland in Hunan Province.展开更多
The goethite residue generated from zinc hydrometallurgy is classified as hazardous solid waste,produced in large quantities,and results in significant zinc loss.The study was conducted on removing iron from FeSO_(4)-...The goethite residue generated from zinc hydrometallurgy is classified as hazardous solid waste,produced in large quantities,and results in significant zinc loss.The study was conducted on removing iron from FeSO_(4)-ZnSO_(4) solution,employing seed-induced nucleation methods.Analysis of the iron removal rate,residue structure,morphology,and elemental composition involved ICP,XRD,FT-IR,and SEM.The existing state of zinc was investigated by combining step-by-step dissolution using hydrochloric acid.Concurrently,iron removal tests were extended to industrial solutions to assess the influence of seeds and solution pH on zinc loss and residue yield.The results revealed that seed addition increased the iron removal rate by 3%,elevated the residual iron content by 6.39%,and mitigated zinc loss by 29.55%in the simulated solution.Seed-induced nucleation prevented excessive nuclei formation,fostering crystal stable growth and high crystallinity.In addition,the zinc content of surface adsorption and crystal internal embedding in the residue was determined,and the zinc distribution on the surface was dense.In contrast,the total amount of zinc within the crystal was higher.The test results in the industrial solution demonstrated that the introduction of seeds expanded the pH range for goethite formation and growth,and the zinc loss per ton of iron removed was reduced by 50.91 kg(34.12%)and the iron residue reduced by 0.17 t(8.72%).展开更多
Owing to the complexity of multicomponent gases,developing multifunctional catalysts for synergistic removal of benzene and toluene remains challenging.The spinel MMn_(2)O_(4)(M=Co,Ni,or Cu)catalysts were successfully...Owing to the complexity of multicomponent gases,developing multifunctional catalysts for synergistic removal of benzene and toluene remains challenging.The spinel MMn_(2)O_(4)(M=Co,Ni,or Cu)catalysts were successfully synthesized via the sol–gel method and tested for their catalytic performance for simultaneous degradation of benzene and toluene.The CuMn_(2)O_(4)sample exhibited the best catalytic performance,the conversion of benzene reached 100%at 350℃,and toluene conversion reached 100%at 250℃.XRD,N_(2)adsorption-desorption,HRTEM-EDS,ED-XRF,Raman spectroscopy,H_(2)-TPR,NH_(3)-TPD,O_(2)-TPD and XPS were used to characterize the physical and chemical properties of MMn_(2)O_(4)catalysts.The excellent redox properties,high concentration of surface Mn4+,and adsorption of oxygen species over the CuMn_(2)O_(4)sample facilitated the simultaneous and efficient removal of benzene and toluene.Additionally,in situ DRIFTS illustrated the intermediate species and reaction mechanism for the synergetic catalytic oxidation of benzene and toluene.Notably,as an effective catalytic material,spinel oxide exhibited excellent synergistic degradation performance for benzene and toluene,providing some insight for the development of efficient multicomponent VOC catalysts.展开更多
The heritage preservation is of great intractability to the conservators as each kind of heritage material has unique and diverse requirements on temperature,humidity and air cleanliness.It is promising for metal-orga...The heritage preservation is of great intractability to the conservators as each kind of heritage material has unique and diverse requirements on temperature,humidity and air cleanliness.It is promising for metal-organic frameworks(MOFs),the multifunctional environment remediation materials,to be applied in heritage environmental protection.The advantages of MOFs lie in their multifunction like adsorption,photocatalysis,sterilization,as well as the controllable structure and properties that could be flexibly adjusted as demands,helping the heritage against various environmental threats.Thereby,the applications and the corresponding mechanisms of MOFs in cultural heritage preservation were reviewed in this work,including harmful gas adsorption,surface waterproofing,particulate matters(PM)removal,anti-bacterial and humidity control of environment.Finally,the selection principles and precautions of MOFs in heritage preservation were discussed,aiming to provide a forward-looking direction for the selection and application of MOFs.展开更多
Ultra-precision components have been widely used to produce advanced optoelectronic equipment.The so-called Electric field enhanced UltraViolet-Induced Jet Machining(EUV-INCJM)is an ultra-precision method that can ach...Ultra-precision components have been widely used to produce advanced optoelectronic equipment.The so-called Electric field enhanced UltraViolet-Induced Jet Machining(EUV-INCJM)is an ultra-precision method that can achieve sub-nanometer level surface quality polishing.This study focuses on the application of the EUV-INCJM with different nozzle structures to a single-crystal of silicon.Two kinds of electro-optic-liquid coupling nozzles with single-jet and multi-jet focusing structures are proposed accordingly.Simulations and experiments have been conducted to verify the material removal performance of these nozzles.The simulation results show that,under the same condition,the flow velocity of the single-jet nozzle is 1.05 times higher than that achieved with the multi-jet configuration,while the current density of the latter is 1.63 times higher than that of the single-jet nozzle.For the single-crystal silicon,the material removal efficiency of the multi-jet focusing nozzle exceeds by about 1.4 times that of the single-jet.These results confirm that the material removal ability of the multi-jet configuration is more suitable for ultra-smooth surface polishing.The surface roughness of Si workpiece was reduced from Rq 1.55 to Rq 0.816 nm with valleys and peaks on its surface being almost completely removed.展开更多
The rapidly growing demand for lithium iron phosphate(LiFePO_(4))as the cathode material of lithium-ion batteries(LIBs)has aggravated the scarcity of phosphorus(P)reserves on Earth.This study introduces an environment...The rapidly growing demand for lithium iron phosphate(LiFePO_(4))as the cathode material of lithium-ion batteries(LIBs)has aggravated the scarcity of phosphorus(P)reserves on Earth.This study introduces an environmentally friendly and economical method of P recovery from municipal wastewater,providing the P source for LiFePO_(4) cathodes.The novel approach utilizes the sludge of Fe-coagulant-based chemical P removal(CPR)in wastewater treatment.After a sintering treatment with acid washing,the CPR sludge,enriched with P and Fe,transforms into purified P-Fe oxides(Fe2.1P1.0O5.6).These oxides can substitute up to 35%of the FePO_(4) reagent as precursor,producing a carbon-coated LiFePO_(4)(LiFePO_(4)/C)cathode with a specific discharge capacity of 114.9 mA·h·g^(-1)at current density of 17 mA·g^(-1)),and cycle stability of 99.2%after 100 cycles.The enhanced cycle performance of the as-prepared LiFePO_(4)/C cathode may be attributed to the incorporations of impurities(such as Ca^(2+)and Na^(+))from sludge,with improved stability of crystal structure.Unlike conventional P-fertilizers,this P recovery technology converts 100%of P in CPR sludge into the production of value-added LiFePO_(4)/C cathodes.The recovered P from municipal wastewater can meet up to 35%of the P demand in the Chinese LIBs industry,offering a cost-effective solution for addressing the pressing challenges of P scarcity.展开更多
Wigner-Ville distribution(WVD)is widely used in the field of signal processing due to its excellent time-frequency(TF)concentration.However,WVD is severely limited by the cross-term when working with multicomponent si...Wigner-Ville distribution(WVD)is widely used in the field of signal processing due to its excellent time-frequency(TF)concentration.However,WVD is severely limited by the cross-term when working with multicomponent signals.In this paper,we analyze the property differences between auto-term and cross-term in the one-dimensional sequence and the two-dimensional plane and approximate entropy and Rényi entropy are employed to describe them,respectively.Based on this information,we propose a new method to achieve adaptive cross-term removal by combining seeded region growing.Compared to other methods,the new method can achieve cross-term removal without decreasing the TF concentration of the auto-term.Simulation and experimental data processing results show that the method is adaptive and is not constrained by the type or distribution of signals.And it performs well in low signal-to-noise ratio environments.展开更多
An abrasive water jet(AWJ)is commonly used to develop deep geothermal resources,such as drilling in hot dry rock(HDR).The influence of rock mineral properties,such as mineral types,mineral contents,and grain size,on t...An abrasive water jet(AWJ)is commonly used to develop deep geothermal resources,such as drilling in hot dry rock(HDR).The influence of rock mineral properties,such as mineral types,mineral contents,and grain size,on the formation of perforation by AWJ is unclear yet.In this study,we investigate AWJ impacts on three types of granite samples with different mineral fractions using a polarizing microscope and scanning electron microscope(SEM).The results show that when the grain size is doubled,the perforation depth increases by 16.22%under the same type of structure and properties.In general,fractures are more likely to be created at the position of rough surfaces caused by abrasive impact,and the form of fractures is determined by the mineral type.In addition,microstructure analysis shows that transgranular fractures typically pass through large feldspar particles and quartz removal occurs along mineral boundaries.The longitudinal extension of perforation depends mainly on the strong kinetic energy of the jet,while the lateral extension is controlled by the backflow.The results contribute to a better understanding of the process involved in the breaking of hard rock by abrasive jets during deep geothermal drilling.展开更多
The removal of harmful cyanobacterial blooms(HCBs)and reuse of the resulting algal sludge are pressing issues in current environmental governance and ecological conservation.Aiming at tackling the abovementioned chall...The removal of harmful cyanobacterial blooms(HCBs)and reuse of the resulting algal sludge are pressing issues in current environmental governance and ecological conservation.Aiming at tackling the abovementioned challenges,titanium(Ti)-based coagulants are promising candidates.However,most of them suffer from poor stability and weak actual algal removal ability,and recycling of the algal sludge usually produces titanium dioxide(TiO_(2))with low photocatalytic ability.In this work,a lanthanum(La)-modified polytitanium chloride(La-PTC)coagulant is reported.La in the La-PTC coagulant serves a"kill two birds with one stone"strategy in algae removal and algae sludge reuse.Owing to the introduction of La ions,the La-PTC coagulant exhibits ultra-high stability and excellent algae removal capability with an efficiency of 98.71%,which is 7.25%higher than that of PTC coagulant.Moreover,recycling algae sludge can prepare high catalytic(2.45 times the commercial P25 TiO_(2))La/C-TiO_(2),where the presence of La enhances its visible light response range and inhibits electron hole recombination.The strategy of this La modified coagulant can not only achieve efficient re moval of HCBs,but also transfo rm the recovered algal sludge into photocatalysts with higher catalytic capacity.展开更多
Atomic surfaces are strictly required by high-performance devices of diamond.Nevertheless,diamond is the hardest material in nature,leading to the low material removal rate(MRR)and high surface roughness during machin...Atomic surfaces are strictly required by high-performance devices of diamond.Nevertheless,diamond is the hardest material in nature,leading to the low material removal rate(MRR)and high surface roughness during machining.Noxious slurries are widely used in conventional chemical mechanical polishing(CMP),resulting in the possible pollution to the environment.Moreover,the traditional slurries normally contain more than four ingredients,causing difficulties to control the process and quality of CMP.To solve these challenges,a novel green CMP for single crystal diamond was developed,consisting of only hydrogen peroxide,diamond abrasive and Prussian blue(PB)/titania catalyst.After CMP,atomic surface is achieved with surface roughness Sa of 0.079 nm,and the MRR is 1168 nm·h^(-1).Thickness of damaged layer is merely 0.66 nm confirmed by transmission electron microscopy(TEM).X-ray photoelectron spectroscopy,electron paramagnetic resonance and TEM reveal that·OH radicals form under ultraviolet irradiation on PB/titania catalyst.The·OH radicals oxidize diamond,transforming it from monocrystalline to amorphous atomic structure,generating a soft amorphous layer.This contributes the high MRR and formation of atomic surface on diamond.The developed novel green CMP offers new insights to achieve atomic surface of diamond for potential use in their high-performance devices.展开更多
基金supported by the Fundamental Research Funds for the Central Publicinterest Scientific Institution(No.2024YSKY-44)the National Key R&D Program of China(No.2023YFC3708003).
文摘To address the problems with catalytic degradation,such as poisoning and inactivation,a simple and efficient gas purging regeneration technique was developed for iron-based catalyst in-situ regeneration.Specifically,the effects of carrier gas types,regeneration temperatures,and granular activated carbon(GAC)addition on iron-based catalyst regeneration were investigated.The Fe_(3)O_(4)/𝛾-Al_(2)O_(3) regenerated at 550°C with additional GAC and 15%water vapor exhibited the optimal degradation efficiency towards polychlorinated biphenyls(PCBs),with an increase from 41.2%to 93.5%,compared with non-regenerated Fe_(3)O_(4)/𝛾-Al_(2)O_(3).In addition,the 60-hour stability test revealed a well-recovered catalytic activity.During the Fe_(3)O_(4)/𝛾-Al_(2)O_(3) regeneration,the coke on the catalyst surface was oxidized and removed in the form of CO_(2),and meanwhile the oxidized Fe(III)was reduced into Fe(II)in the catalyst.This study provides a safe and efficient iron-based catalyst regeneration technology for PCB off-gas degradation and reveals the catalytic activity recovery mechanism during catalyst regeneration.
基金supported by the Natural Science Foundation of China(No.52470105)the Young Taishan Scholars Program of Shandong Province(No.358202103017).
文摘The discharge of micro-polluted water from sources such as agricultural runoff,urban stormwater,and treated effluents presents significant challenges to aquatic ecosystems.Constructed wetlands(CWs)have gained recog-nition as an eco-friendly solution for removing pollutants from various wastewater sources and are increasingly applied for micro-polluted water treatment.By reviewing 78 full-scale CW studies from Web of Science,it is summarized that the ranges of ammonium nitrogen(NH4+-N)concentrations in runoff,wastewater treatment plant effluent and polluted river were 0.1–6.6,0.3–12.3,and 0.2–41.1 mg/L,respectively.The ranges of ni-trate nitrogen concentrations were 0.2–14.2,0–5.7,and 0–2.6 mg/L,respectively.Removal efficiencies of CWs for micro-polluted water varied by CW types.The total nitrogen removal efficiencies for subsurface-flow CWs,free-water surface-flow CWs,and hybrid CWs ranged from 27.4%to 66.5%,16.8%to 89.8%,and 19.4%to 88.2%,respectively.The NH4+-N removal efficiencies ranged from 34.2%to 73.6%,38.4%to 89.4%and 13.5%to 94.2%,respectively.Additionally,other factors influencing contaminant removal efficiency such as hydraulic retention time,vegetation types,redox micro-environment and influent water quality were evaluated.Based on these findings,two strategies for improving the purification performance of CWs were proposed:the selection of incorporating electron donor substrates and the optimization of operation parameters.This paper serves as a synthesis of information to guide future research and full-scale CW applications in micro-polluted water treatment.
文摘Environmental pollution,energy consumption,and greenhouse gas emissions are critical global issues.To address these challenges,optimizing skimmer coatings is a major step in commercializing cleaning oil stains.This research presents a novel approach to creating and refining oil absorbent coatings,introducing a unique oil spill removal skimmer enhanced with a super hydrophobic polyaniline(PANI)nanofiber coating.The goal of this study was to improve oil absorption performance,increase the contact angle,lower drag,reduce energy consumption,achieve high desirability,and lower production costs.PANI treated with hydrochloric acid was a key focus as it resulted in higher porosity and smaller pore diameters,providing a larger surface area,which are crucial factors for boosting oil absorption and minimizing drag.To optimize optimal nanofiber morphology,PANI synthesized with methanesulfonic acid was first dedoped and then redoped with hydrochloric acid.After optimization,the most effective skimmer coating was achieved using a formulation consisting of 0.1%PANI,an ammonium persulfate/aniline ratio of 0.4,and an acid/aniline ratio of 9.689,along with redoped PANI nanofibers.The optimized skimmer exhibited a remarkable contact angle of 177.477°.The coating achieved drag reduction of 32%,oil absorption of 88.725%,a cost of$1.710,and a desirability rating of 78.5%.In this study,an optimized skimmer coat containing super hydrophobic coat-PANI nanofibers was fabricated.By enhancing contact angle and reducing drag,these coatings increased the skimmer performance by improving oil absorption and reducing fuel consumption.
基金funded by NIH grants HL154720-03S1, AG057587, AG074283, DK122708-03S1, BrightFocus ADR A20183775Brown Foundation 2020 Healthy Aging Initiative (to WC)
文摘Microglia are the macrophages that populate the brain parenchyma.Research in the past decades has identified them as both essential guardians of the brain and significant contributors to various neurological diseases.A highly versatile cell type,microglia have been shown to fulfill a multitude of critical roles in the central nervous system,including facilitating neurogenesis and myelination,pruning synapses,removing debris and waste,modulating neuronal activity,supporting the blood-brain barrier,repairing tissue damage,and surveilling against microbial invasions under physiological conditions(Prinz et al.,2021;Paolicelli et al.,2022).
基金financial support from the Nuclear Energy Science&Technology and Human Resource Development Project of the Japan Atomic Energy Agency/Collaborative Laboratories for Advanced Decommissioning Science(No.R04I034)The author Ruicong Xu appreciates the scholarship(financial support)from the China Scholarship Council(CSC,No.202106380073).
文摘Laser-induced aerosols,predominantly submicron in size,pose significant environmental and health risks during the decommissioning of nuclear reactors.This study experimentally investigated the removal of laser-generated aerosol particles using a water spray system integrated with an innovative system for pre-injecting electrically charged mist in our facility.To simulate aerosol generation in reactor decommissioning,a high-power laser was used to irradiate various materials(including stainless steel,carbon steel,and concrete),generating aerosol particles that were agglomerated with injected water mist and subsequently scavenged by water spray.Experimental results demonstrate enhanced aerosol removal via aerosol-mist agglomeration,with charged mist significantly improving particle capture by increasing wettability and size.The average improvements for the stainless steel,carbon steel,and concrete were 40%,44%,and 21%,respectively.The results of experiments using charged mist with different polarities(both positive and negative)and different surface coatings reveal that the dominant polarity of aerosols varies with the irradiated materials,influenced by their crystal structure and electron emission properties.Notably,surface coatings such as ZrO_(2)and CeO_(2)were found to possibly alter aerosol charging characteristics,thereby affecting aerosol removal efficiency with charged mist configurations.The innovative aerosol-mist agglomeration approach shows promise in mitigating radiation exposure,ensuring environmental safety,and reducing contaminated water during reactor dismantling.This study contributes critical knowledge for the development of advanced aerosol management strategies for nuclear reactor decommissioning.The understanding obtained in this work is also expected to be useful for various environmental and chemical engineering applications such as gas decontamination,air purification,and pollution control.
基金financially supported by the National Natural Science Foundation of China(Nos.92160301,92060203,52175415 and 52205475)the Science Center for Gas Turbine Project(No.P2023-B-IV-003-001)+1 种基金the Natural Science Foundation of Jiangsu Province(No.BK20210295)the Huaqiao University Engineering Research Center of Brittle Materials Machining(MOE,2023IME-001)。
文摘The remarkable ability of titanium alloys to preserve their superior physical and chemical characteristics when subjected to extreme conditions significantly enhances their importance in the aerospace,military,and medical sectors.However,conventional machining of titanium alloys leads to elevated tool wear,development of surface defects,and reduced machining efficiency due to their low heat conductivity,and chemical affinity.These issues can be somewhat counteracted by integrating ultrasonic vibration in the conventional machining of titanium alloys and also enhance sustainability.This review article offers a holistic evaluation of the influence of ultrasonic vibration-assisted milling and turning on cutting forces,temperature,tool wear,and surface integrity,encompassing surface morphology,surface roughness,surface residual stress,surface hardness,and surface tribological properties during titanium alloys machining.Furthermore,it investigates the sustainability aspect that has not been previously examined.Studies on the performance of ultrasonic-assisted cutting revealed several advantages,including decreased cutting forces and cutting temperature,improved tool life,and a better-machined surface during machining.Consequently,the sustainability factor is improved due to minimized energy consumption and residual waste.In conclusion,the key challenges and future prospects in the ultrasonic-assisted cutting of titanium alloys are also discussed.This review article provides beneficial knowledge for manufactur-ers and researchers regarding ultrasonic vibration-assisted cutting of titanium alloy and will play an important role in achieving sustainability in the industry.
基金supported by the Special Funds for Chengde national innovation demonstration area construction of science and technology special project sustainable development agenda(No.202104F001)the National Basic Research Program of China(No.2019YFC0408602).
文摘Nitrogen removal from domestic sewage is usually limited by insufficient carbon source and electron donor.An economical solid carbon source was developed by composition of polyvinyl alcohol,sodium alginate,and corncob,which was utilized as external carbon source in the anaerobic anoxic oxic(AAO)-biofilter for the treatment of low carbon-to-nitrogen ratio domestic sewage,and the nitrogen removal was remarkably improved from 63.2%to 96.5%.Furthermore,the effluent chemical oxygen demand maintained at 35 mg/L or even lower,and the total nitrogenwas reduced to less than 2mg/L.Metagenomic analysis demonstrated that the microbial communities responsible for potential denitrification and organic matter degradation in both AAO and the biofilter reactors were mainly composed of Proteobacteria and Bacteroides,respectively.The solid carbon source addition resulted in relatively high abundance of functional enzymes responsible for NO_(3)^(−)-N to NO_(2)^(−)-N con-version in both AAO and the biofilter reactors,thus enabled stable reaction.The carbon source addition during glycolysis primarily led to the increase of genes associated with the metabolic conversion of fructose 1.6P2 to glycerol-3P The reactor maintained high abun-dance of genes related to the tricarboxylic acid cycle,and then guaranteed efficient carbon metabolism.The results indicate that the composite carbon source is feasible for denitri-fication enhancement of AAO-biofilter,which contribute to the theoretical foundation for practical nitrogen removal application.
基金support from the earmarked fund for XJARS(No.XJARS-06)the Bingtuan Science and Technology Program(Nos.2021DB019,2022CB001-01)+1 种基金the National Natural Science Foundation of China(No.42275014)the Guangdong Foundation for Program of Science and Technology Research,China(No.2023B1212060044)。
文摘Current research primarily focuses on emerging organic pollutants,with limited attention to emerging inorganic pollutants (EIPs).However,due to advances in detection technology and the escalating environmental and health challenges posed by pollution,there is a growing interest in treating waters contaminated with EIPs.This paper explores biochar characteristics and modification methods,encompassing physical,chemical,and biological approaches for adsorbing EIPs.It offers a comprehensive review of research advancements in employing biochar for EIPs remediation in water,outlines the adsorption mechanisms of EIPs by biochar,and presents an environmental and economic analysis.It can be concluded that using biochar for the adsorption of EIPs in wastewater exhibits promising potential.Nonetheless,it is noteworthy that certain EIPs like Au(III),Rh(III),Ir(III),Ru(III),Os(III),Sc(III),and Y(III),have not been extensively investigated regarding their adsorption onto biochar.This comprehensive review will catalyze further inquiry into the biochar-based adsorption of EIPs,addressing current research deficiencies and advancing the practical implementation of biochar as a potent substrate for EIP removal from wastewater streams.
基金The financial support from the National Natural Science Foundation of China(22127812,22278433,22178379)the National Key Research and Development Program of China(2021YFC2800902)are gratefully acknowledged。
文摘The mechanism of hydrate-based desalination is that water molecules would transfer to the hydrate phase during gas hydrate formation process,while the salt ions would be conversely concentrated in the unreacted saltwater.However,the salt concentration of hydrate decomposed water and the desalination degree of hydrate phase are still unclear.The biggest challenge is how to effectively separate the hydrate phase and the remaining unreacted salt water,and then decompose the hydrate phase to measure the salt concentration of hydrate melt water.This work developed an apparatus and pressure-driven filtration method to efficiently separate the hydrate phase and the remaining unreacted saltwater.On this basis,the single hydrate phase was obtained,then it was dissociated and the salt concentration of hydrate melt water was measured.The experimental results demonstrate that when the initial salt mass concentration is 0.3% to 8.0%,the salt removal efficiency for NaCl solution is 15.9% to 29.8%by forming CO_(2) hydrate,while for CaCl_(2) solution is 28.9%to 45.5%.The solute CaCl_(2) is easier to be removed than solute NaCl.In addition,the salt removal efficiency for forming CO_(2) hydrate is higher than that for forming methane hydrate.The multi-stage desalination can continuously decrease the salt concentration of hydrate dissociated water,and the salt removal efficiency per stage is around 20%.
文摘Magnesium(Mg)alloys are widely used lightweight structural materials for automobiles and help reduce carbon emissions.However,their use increases the production of Mg alloy scrap,which is recycled at a much lower rate than aluminum,and its greater complexity poses challenges to existing recycling processes.Although vacuum distillation can be used to recycle Mg alloy scrap,this requires optimizing and maximizing metal recirculation,but there has been no thermodynamic analysis of this process.In this study,the feasibility and controllability of separating inclusions and 23 metal impurities were evaluated,and their distribution and removal limits were quantified.Thermodynamic analyses and experimental results showed that inclusions and impurity metals of separation coefficient lgβ_(i)≤-5,including Cu,Fe,Co,and Ni below 0.001 ppm,could be removed from the matrix.All Zn entered the recycled Mg,while impurities with-1<lgβ_(i)<-5 such as Li,Ca,and Mn severely affected the purity of the recycled Mg during the later stage of distillation.Therefore,an optimization strategy for vacuum distillation recycling:lower temperatures and higher system pressures for Zn separation in the early stage,and the early termination of the recovery process in the later stage or a continuous supply of raw melt can also prevent contamination during recycling.The alloying elements Al and Zn in Mg alloy scrap can be further recovered and purified by vacuum distillation when economically feasible,to maximize the recycling of metal resources.
基金supported by the National Natural Science Foundation of China(No.U20A20108)the National Key Research and Development Program of China(No.2022YFD1700102)the Key Research and Development Program of Hunan Province(No.2022NK2014).
文摘Several studies have demonstrated that reintroducing crop straw to fields may intensify cadmium(Cd)contamination in agricultural soils.However,the specific effects of long-term straw management practices on Cd concentration and its bioavailability in soil-rice ecosystems remain unclear.In this context,to explore the influence of straw return(SR)and straw removal(NSR)on Cd accumulation in both soil and rice within a double-cropping system,we conducted a four-year field study.Our research study unveiled that NSR consistently decreased soil Cd concentration and its bioavailability by approximately 16.93%–27.30%and 8.23%–21.05%respectively across both study sites.Conversely,SR resulted in a substantial increase in soil Cd bioavailability,ranging from 38.64%–53.95%.Notably,compared to NSR,SR significantly increased total soil Cd by 5.47%–36.58%and increased Cd content in brown rice by 8.00%–100.24%.Remarkably,after four consecutive years of NSR,brown rice Cd concentration at the Changfeng site compiled with national safety standards(GB 2762–2022).Additionally,returning early rice strawsignificantly raised soil Cd bioavailability for the subsequent crop,more so than late rice straw did for the early rice the following year.The findings suggest that traditional double-cropping cultivation with straw removal can effectively mitigate Cd contamination risks in crops and farmland in Hunan Province.
基金Project(2018YFC1900403) supported by the National Key Research and Development Program of ChinaProject(CX20210197) supported by the Postgraduate Scientific Research Innovation Project of Hunan Province,China+1 种基金Project(202206370103) supported by the China Scholarship CouncilProject(2021zzts0115) supported by the Fundamental Research Funds for the Central Universities,China。
文摘The goethite residue generated from zinc hydrometallurgy is classified as hazardous solid waste,produced in large quantities,and results in significant zinc loss.The study was conducted on removing iron from FeSO_(4)-ZnSO_(4) solution,employing seed-induced nucleation methods.Analysis of the iron removal rate,residue structure,morphology,and elemental composition involved ICP,XRD,FT-IR,and SEM.The existing state of zinc was investigated by combining step-by-step dissolution using hydrochloric acid.Concurrently,iron removal tests were extended to industrial solutions to assess the influence of seeds and solution pH on zinc loss and residue yield.The results revealed that seed addition increased the iron removal rate by 3%,elevated the residual iron content by 6.39%,and mitigated zinc loss by 29.55%in the simulated solution.Seed-induced nucleation prevented excessive nuclei formation,fostering crystal stable growth and high crystallinity.In addition,the zinc content of surface adsorption and crystal internal embedding in the residue was determined,and the zinc distribution on the surface was dense.In contrast,the total amount of zinc within the crystal was higher.The test results in the industrial solution demonstrated that the introduction of seeds expanded the pH range for goethite formation and growth,and the zinc loss per ton of iron removed was reduced by 50.91 kg(34.12%)and the iron residue reduced by 0.17 t(8.72%).
基金supported by the National Natural Science Foundation of China(Nos.22206146,22006079,and U21A20524)the Fundamental Research Funds for the Central Universities,the Youth Innovation Promotion Association of Chinese Academy of Sciences,the Fundamental Research Program of Shanxi Province(No.202103021223280)+1 种基金the Special Fund for Science and Technology Innovation Teams of Shanxi Province(No.202204051002026)the Natural Science Foundation of Shandong Province(No.ZR2021QB133).
文摘Owing to the complexity of multicomponent gases,developing multifunctional catalysts for synergistic removal of benzene and toluene remains challenging.The spinel MMn_(2)O_(4)(M=Co,Ni,or Cu)catalysts were successfully synthesized via the sol–gel method and tested for their catalytic performance for simultaneous degradation of benzene and toluene.The CuMn_(2)O_(4)sample exhibited the best catalytic performance,the conversion of benzene reached 100%at 350℃,and toluene conversion reached 100%at 250℃.XRD,N_(2)adsorption-desorption,HRTEM-EDS,ED-XRF,Raman spectroscopy,H_(2)-TPR,NH_(3)-TPD,O_(2)-TPD and XPS were used to characterize the physical and chemical properties of MMn_(2)O_(4)catalysts.The excellent redox properties,high concentration of surface Mn4+,and adsorption of oxygen species over the CuMn_(2)O_(4)sample facilitated the simultaneous and efficient removal of benzene and toluene.Additionally,in situ DRIFTS illustrated the intermediate species and reaction mechanism for the synergetic catalytic oxidation of benzene and toluene.Notably,as an effective catalytic material,spinel oxide exhibited excellent synergistic degradation performance for benzene and toluene,providing some insight for the development of efficient multicomponent VOC catalysts.
基金supported by the National Natural Science Foundation of China(Nos.52308300,52370025,52108266).
文摘The heritage preservation is of great intractability to the conservators as each kind of heritage material has unique and diverse requirements on temperature,humidity and air cleanliness.It is promising for metal-organic frameworks(MOFs),the multifunctional environment remediation materials,to be applied in heritage environmental protection.The advantages of MOFs lie in their multifunction like adsorption,photocatalysis,sterilization,as well as the controllable structure and properties that could be flexibly adjusted as demands,helping the heritage against various environmental threats.Thereby,the applications and the corresponding mechanisms of MOFs in cultural heritage preservation were reviewed in this work,including harmful gas adsorption,surface waterproofing,particulate matters(PM)removal,anti-bacterial and humidity control of environment.Finally,the selection principles and precautions of MOFs in heritage preservation were discussed,aiming to provide a forward-looking direction for the selection and application of MOFs.
基金supported by the National Natural Science Foundation of China(52365056).
文摘Ultra-precision components have been widely used to produce advanced optoelectronic equipment.The so-called Electric field enhanced UltraViolet-Induced Jet Machining(EUV-INCJM)is an ultra-precision method that can achieve sub-nanometer level surface quality polishing.This study focuses on the application of the EUV-INCJM with different nozzle structures to a single-crystal of silicon.Two kinds of electro-optic-liquid coupling nozzles with single-jet and multi-jet focusing structures are proposed accordingly.Simulations and experiments have been conducted to verify the material removal performance of these nozzles.The simulation results show that,under the same condition,the flow velocity of the single-jet nozzle is 1.05 times higher than that achieved with the multi-jet configuration,while the current density of the latter is 1.63 times higher than that of the single-jet nozzle.For the single-crystal silicon,the material removal efficiency of the multi-jet focusing nozzle exceeds by about 1.4 times that of the single-jet.These results confirm that the material removal ability of the multi-jet configuration is more suitable for ultra-smooth surface polishing.The surface roughness of Si workpiece was reduced from Rq 1.55 to Rq 0.816 nm with valleys and peaks on its surface being almost completely removed.
基金supported by the National Natural Science Foundation of China(52100093,52270128,and 52261135627)the Guangdong Basic and Applied Basic Research Foundation(2023A1515011734 and 2021B1515120068)+2 种基金the Municipal Science and Technology Innovation Council of the Shen-zhen Government(KCXFZ20211020163556020 and SGDX20230116092359002)the Research Grants Council(17210219)the Innovation and Technology Fund(ITS/242/20FP)of the Hong Kong SAR Government。
文摘The rapidly growing demand for lithium iron phosphate(LiFePO_(4))as the cathode material of lithium-ion batteries(LIBs)has aggravated the scarcity of phosphorus(P)reserves on Earth.This study introduces an environmentally friendly and economical method of P recovery from municipal wastewater,providing the P source for LiFePO_(4) cathodes.The novel approach utilizes the sludge of Fe-coagulant-based chemical P removal(CPR)in wastewater treatment.After a sintering treatment with acid washing,the CPR sludge,enriched with P and Fe,transforms into purified P-Fe oxides(Fe2.1P1.0O5.6).These oxides can substitute up to 35%of the FePO_(4) reagent as precursor,producing a carbon-coated LiFePO_(4)(LiFePO_(4)/C)cathode with a specific discharge capacity of 114.9 mA·h·g^(-1)at current density of 17 mA·g^(-1)),and cycle stability of 99.2%after 100 cycles.The enhanced cycle performance of the as-prepared LiFePO_(4)/C cathode may be attributed to the incorporations of impurities(such as Ca^(2+)and Na^(+))from sludge,with improved stability of crystal structure.Unlike conventional P-fertilizers,this P recovery technology converts 100%of P in CPR sludge into the production of value-added LiFePO_(4)/C cathodes.The recovered P from municipal wastewater can meet up to 35%of the P demand in the Chinese LIBs industry,offering a cost-effective solution for addressing the pressing challenges of P scarcity.
基金Supported by the National Natural Science Foundation of China(62201171).
文摘Wigner-Ville distribution(WVD)is widely used in the field of signal processing due to its excellent time-frequency(TF)concentration.However,WVD is severely limited by the cross-term when working with multicomponent signals.In this paper,we analyze the property differences between auto-term and cross-term in the one-dimensional sequence and the two-dimensional plane and approximate entropy and Rényi entropy are employed to describe them,respectively.Based on this information,we propose a new method to achieve adaptive cross-term removal by combining seeded region growing.Compared to other methods,the new method can achieve cross-term removal without decreasing the TF concentration of the auto-term.Simulation and experimental data processing results show that the method is adaptive and is not constrained by the type or distribution of signals.And it performs well in low signal-to-noise ratio environments.
基金supported by the Postdoctoral Fellowship Program of CPSF(Grant No.GZC20233326)the Chongqing Science Fund for Distinguished Young Scholars(Grant No.CSTB2022NSCQJQX0028)the National Natural Science Foundation of China(Grant Nos.U23A20597,52274112).
文摘An abrasive water jet(AWJ)is commonly used to develop deep geothermal resources,such as drilling in hot dry rock(HDR).The influence of rock mineral properties,such as mineral types,mineral contents,and grain size,on the formation of perforation by AWJ is unclear yet.In this study,we investigate AWJ impacts on three types of granite samples with different mineral fractions using a polarizing microscope and scanning electron microscope(SEM).The results show that when the grain size is doubled,the perforation depth increases by 16.22%under the same type of structure and properties.In general,fractures are more likely to be created at the position of rough surfaces caused by abrasive impact,and the form of fractures is determined by the mineral type.In addition,microstructure analysis shows that transgranular fractures typically pass through large feldspar particles and quartz removal occurs along mineral boundaries.The longitudinal extension of perforation depends mainly on the strong kinetic energy of the jet,while the lateral extension is controlled by the backflow.The results contribute to a better understanding of the process involved in the breaking of hard rock by abrasive jets during deep geothermal drilling.
基金Project supported by the National Natural Science Foundation of China(62175266,61775245)。
文摘The removal of harmful cyanobacterial blooms(HCBs)and reuse of the resulting algal sludge are pressing issues in current environmental governance and ecological conservation.Aiming at tackling the abovementioned challenges,titanium(Ti)-based coagulants are promising candidates.However,most of them suffer from poor stability and weak actual algal removal ability,and recycling of the algal sludge usually produces titanium dioxide(TiO_(2))with low photocatalytic ability.In this work,a lanthanum(La)-modified polytitanium chloride(La-PTC)coagulant is reported.La in the La-PTC coagulant serves a"kill two birds with one stone"strategy in algae removal and algae sludge reuse.Owing to the introduction of La ions,the La-PTC coagulant exhibits ultra-high stability and excellent algae removal capability with an efficiency of 98.71%,which is 7.25%higher than that of PTC coagulant.Moreover,recycling algae sludge can prepare high catalytic(2.45 times the commercial P25 TiO_(2))La/C-TiO_(2),where the presence of La enhances its visible light response range and inhibits electron hole recombination.The strategy of this La modified coagulant can not only achieve efficient re moval of HCBs,but also transfo rm the recovered algal sludge into photocatalysts with higher catalytic capacity.
基金financial support from the National Key Research and Development Program of China(2018YFA0703400)the Fundamental Research Funds for the Provincial Universities of Zhejiang(GK239909299001021)+1 种基金the Ninth China Association for Science and Technology Youth Talent Lift Project Support Plan(KYZ015324002)the Changjiang Scholars Program of Chinese Ministry of Education。
文摘Atomic surfaces are strictly required by high-performance devices of diamond.Nevertheless,diamond is the hardest material in nature,leading to the low material removal rate(MRR)and high surface roughness during machining.Noxious slurries are widely used in conventional chemical mechanical polishing(CMP),resulting in the possible pollution to the environment.Moreover,the traditional slurries normally contain more than four ingredients,causing difficulties to control the process and quality of CMP.To solve these challenges,a novel green CMP for single crystal diamond was developed,consisting of only hydrogen peroxide,diamond abrasive and Prussian blue(PB)/titania catalyst.After CMP,atomic surface is achieved with surface roughness Sa of 0.079 nm,and the MRR is 1168 nm·h^(-1).Thickness of damaged layer is merely 0.66 nm confirmed by transmission electron microscopy(TEM).X-ray photoelectron spectroscopy,electron paramagnetic resonance and TEM reveal that·OH radicals form under ultraviolet irradiation on PB/titania catalyst.The·OH radicals oxidize diamond,transforming it from monocrystalline to amorphous atomic structure,generating a soft amorphous layer.This contributes the high MRR and formation of atomic surface on diamond.The developed novel green CMP offers new insights to achieve atomic surface of diamond for potential use in their high-performance devices.
