The antibacterial polyamide 6(PA6)material has attracted great research interest due to its wide ap-plication in food packaging,biomedical fields,functional textiles,and other fields.However,it is still a challenge to...The antibacterial polyamide 6(PA6)material has attracted great research interest due to its wide ap-plication in food packaging,biomedical fields,functional textiles,and other fields.However,it is still a challenge to prepare intrinsically antibacterial PA6 with highly efficient and durably antibacterial activity via polymerization.Herein,the antibacterial imidazolium ionic liquid of 3-carboxymethyl-1-decyl imida-zole chloride was designed and synthesized for adapting the polymerization and processing temperature of PA6.Then antibacterial PA6(PA6-IL)was synthesized through hydrolyzed ring-opening copolymeriza-tion with imidazolium at the end of the backbones.Compared to physical blending or post-modification methods,antibacterial agents as end-capping reagents of polymer backbones endowed PA6 with intrin-sic antibacterial activity.As expected,the obtained PA6-IL exhibited not just comparable physicochemical and mechanical properties to conventional PA6 but excellent antibacterial activity of low antibacterial time to 60 min and durability for 28 days.Additionally,the corresponding electrospun PA6-IL nanofi-brous membranes showed homogenous morphology and remarkable hydrophilicity of 7.7° as well as the high-efficient antibacterial activity.Melt-spun PA6-IL microfibers revealed a smooth surface as well as enhanced tensile strength and increased breaking elongation compared to those of conventional PA6.The PA6-IL microfibers also behaved with excellent antibacterial efficiency and durability.Accordingly,this work provides a feasible and straightforward strategy to prepare durably and intrinsically antibacterial PA6 materials especially PA6 fibers,which can be widely applied in the textiles field.展开更多
A new fertilizer of cocrystal type,known as durably efficacious ammonium bicarbonate(DEAB),has been developed by adding a certain amount of dicyandiamide(DCD)as an ammonia-stabilizing agent to ammonium bearbenate(AB)d...A new fertilizer of cocrystal type,known as durably efficacious ammonium bicarbonate(DEAB),has been developed by adding a certain amount of dicyandiamide(DCD)as an ammonia-stabilizing agent to ammonium bearbenate(AB)during the process of its production.As compared with AB,DEAB was found to have a reduction of direct volatilization loss by 53%,a fertilizer availability period prolonged from 35-45 to 90-110 d,and an increase in the rate of nitrogen in fertilizer being utilized by 5.9%-10.2%,and a saving of the amount of fertilizer to be ap-phed by 20%-30%for the same level of yield,or an increase of the crop yield by over 10%for the same level of ni-tregen fertilization;in addition,it was found to show usually a function of promoting the crop to early mature.It can be applied as basal dressing all in one time to soil and thus also used as a labour-saving and crop yield-increasing fertil-izer for is non-mtertillage,plastics film covering and water-saving agriculture.展开更多
Improving the electric output and durability of triboelectric nanogenerator(TENG)remains a great challenge.In sliding-mode TENG,surface charge dissipation and charge leakage caused by the volume effect result in serio...Improving the electric output and durability of triboelectric nanogenerator(TENG)remains a great challenge.In sliding-mode TENG,surface charge dissipation and charge leakage caused by the volume effect result in serious energy waste.In this work,a durable dual output mode TENG(DDO-TENG),which includes alteranting current and direct current output modes,is designed to capture the dissipating charges in the surface of charge space accumulation area and the inner leakage charge in porous network to further improve the output performance of sliding TENGs.The output charge density of DDO-TENG reaches 0.847 mC m^(-2),which is 2.39 times as that of the single mode device.In addition,it has strong durability,remaining 95.7%after over 271 k cycles,and it can continuously power electronics by harvesting wind energy.This work provides a strategy for achieving the improvement on output performance and durability and expands the application of TENG.展开更多
This study introduces superabsorbent polymers(SAP)into recycled concrete and,through freeze-thaw cycle tests,unconfined compressive strength tests,and nuclear magnetic resonance(NMR)analysis,evaluates the freeze-thaw ...This study introduces superabsorbent polymers(SAP)into recycled concrete and,through freeze-thaw cycle tests,unconfined compressive strength tests,and nuclear magnetic resonance(NMR)analysis,evaluates the freeze-thaw resistance and durability of recycled concrete samples under varying freeze-thaw cycles.The results indicate that an appropriate addition of SAP significantly enhances the freeze-thaw resistance of recycled concrete.After 200 freeze-thaw cycles,the RS0.6 sample retained good surface integrity,demonstrating the best performance.Compared to NAC,its mass loss decreased by 1.16%,the relative dynamic modulus improved by 7.01%,and the compressive strength loss rate decreased by 5.41%.Additionally,T2 spectrum analysis revealed that adding SAP optimized the pore structure of recycled concrete and mitigated pore development during freeze-thaw cycles.As the number of freeze-thaw cycles increased,the RS0.3 and RS0.6 samples demonstrated superior frost resistance compared to NAC.However,an excessive amount of SAP increased pore expansion during subsequent freeze-thaw cycles,ultimately weakening frost resistance.展开更多
Concrete lining slabs of long-distance water conveyance projects in northern China are susceptible to freeze-thaw erosion,which places higher requirements on the performance of repair materials for eroded areas,such a...Concrete lining slabs of long-distance water conveyance projects in northern China are susceptible to freeze-thaw erosion,which places higher requirements on the performance of repair materials for eroded areas,such as frost resistance,adhesion,coating penetration depth,water absorption ratio,and durability.Performance tests were conducted on existing repair materials,and the results showed that:XYPEX exhibits better performance compared to other materials;the high-performance ultra-nano silane impregnant has outstanding performance;and the composite coating demonstrates excellent comprehensive performance.The composite material modified with nano-SiO_(2) has further improved strength and durability.展开更多
The development of Pt-free catalysts for the oxygen reduction reaction(ORR)is a great issue for meeting the cost challenges of proton exchange membrane fuel cells(PEMFCs)in commercial applications.In this work,a serie...The development of Pt-free catalysts for the oxygen reduction reaction(ORR)is a great issue for meeting the cost challenges of proton exchange membrane fuel cells(PEMFCs)in commercial applications.In this work,a series of RuCo/C catalysts were synthesized by NaBH4 reduction method under the premise that the total metal mass percentage was 20%.X-ray diffraction(XRD)patterns and scanning electron microscopy(SEM)confirmed the formation of single-phase nanoparticles with an average size of 33 nm.Cyclic voltammograms(CV)and linear sweep voltammograms(LSV)tests indicated that RuCo(2:1)/C catalyst had the optimal ORR properties.Additionally,the RuCo(2:1)/C catalyst remarkably sustained 98.1% of its activity even after 3000 cycles,surpassing the performance of Pt/C(84.8%).Analysis of the elemental state of the catalyst surface after cycling using X-ray photoelectron spectroscopy(XPS)revealed that the Ru^(0) percentage of RuCo(2:1)/C decreased by 2.2%(from 66.3% to 64.1%),while the Pt^(0) percentage of Pt/C decreased by 7.1%(from 53.3% to 46.2%).It is suggested that the synergy between Ru and Co holds the potential to pave the way for future low-cost and highly stable ORR catalysts,offering significant promise in the context of PEMFCs.展开更多
Bio-carbonation of reactive MgO has been regarded as a promising and eco-friendly method for construction and demolition waste(CDW)cementation in various geotechnical engineering applications.However,the beneficial ef...Bio-carbonation of reactive MgO has been regarded as a promising and eco-friendly method for construction and demolition waste(CDW)cementation in various geotechnical engineering applications.However,the beneficial effect of bio-carbonation of reactive MgO cemented CDW(BCM-samples)can be altered when exposed to wetting-drying cycles induced by extreme climate changes or groundwater fluctuations.To better understand the durability of BCM-samples and their underlying deterioration mechanisms,a series of BCM-samples was prepared to investigate their physical-mechanical performance and microstructure evolution subjected to the wetting-drying cycles.The results indicated that the wetting-drying cycles can deteriorate the BCM-samples,and their physical-mechanical behaviors change quickly at the cycle beginning and then smoothly after 2 cycles.With the increase in cycling,the apparent deterioration with efflorescence and microcrack development can be observed.The mass loss and water absorption rates increased while the dry density,compressional wave velocity,and unconfined compression strength decreased.Urea pre-hydrolysis treatment can significantly improve the durability of BCM-samples,as the more hydrated magnesia carbonates(HMCs)enhance the cementing effects.After 10 cycles,the UCS of pre-hydrolyzed samples decreased 25.4%to 4.45 MPa,while that of ordinary samples decreased 50.7%to 1.20 MPa.The deterioration of BCM-samples caused by wetting-drying cycles can be attributed to two factors.One of the main factors is the structural integrity changes caused by the rapid loss of soluble material at the initial cycling stages.Another factor is the decrease in cementation induced by the loss of brucite and HMCs at the following cycle stages.展开更多
To study the durability of concrete in harsh environments in Northwest China,concrete was prepared with various durability-improving materials such as concrete anti-erosion inhibitor(SBT-TIA),acrylate polymer(AP),supe...To study the durability of concrete in harsh environments in Northwest China,concrete was prepared with various durability-improving materials such as concrete anti-erosion inhibitor(SBT-TIA),acrylate polymer(AP),super absorbent resin(SAP).The erosion mode and internal deterioration mechanism under salt freeze-thaw cycle and dry-wet cycle were explored.The results show that the addition of enhancing materials can effectively improve the resistance of concrete to salt freezing and sulfate erosion:the relevant indexes of concrete added with X-AP and T-AP are improved after salt freeze-thaw cycles;concrete added with SBTTIA shows optimal sulfate corrosion resistance;and concrete added with AP displays the best resistance to salt freezing.Microanalysis shows that the increase in the number of cycles decreases the generation of internal hydration products and defects in concrete mixed with enhancing materials and improves the related indexes.Based on the Wiener model analysis,the reliability of concrete with different lithologies and enhancing materials is improved,which may provide a reference for the application of manufactured sand concrete and enhancing materials in Northwest China,especially for the study of the improvement effects and mechanism of enhancing materials on the performance of concrete.展开更多
1.Introduction.Pancreaticoduodenectomy is an essential surgical procedure for the treatment of malignant tumors in the pancreatic head,distal common bile duct,and duodenal papilla,and is widely used in clinical practi...1.Introduction.Pancreaticoduodenectomy is an essential surgical procedure for the treatment of malignant tumors in the pancreatic head,distal common bile duct,and duodenal papilla,and is widely used in clinical practice.One of the primary determinants of surgical success is the durability of the pancreaticojejunal anastomosis.展开更多
The rapid decay of the surface wettability of plasma-treated polymers remains a critical limitation for their practical application in advanced materials.This study introduces a continuous atmospheric pressure plasma(...The rapid decay of the surface wettability of plasma-treated polymers remains a critical limitation for their practical application in advanced materials.This study introduces a continuous atmospheric pressure plasma(APP)technique for fabricating polyethylene(PE)separators with durable wettability,and elucidates the underlying mechanism.A systematic comparison of APP treatments with non-deposition and deposition gases,including Ar,Ar/O_(2),Ar/tetramethylcyclotetrasiloxane(TMCTS),and Ar/O_(2)/TMCTS,revealed the key impact factors in achieving durable wettability.Owing to the synergistic interactions of SiO_(x)C_(y)H_(z)nanoparticulate deposition,physical etching,and oxidative functionalization,the PE separator treated by Ar/O_(2)/TMCTS exhibited a 17.5-fold electrolyte wetting area compared to the original one.The improved surface energy and roughness of the SiO_(x)C_(y)H_(z)nanoparticle coating enhanced its electrochemical performance.The ionic conductivity increased by 1.9 times,while the charge transfer resistance decreased by 73.7%.Remarkably,owing to further oxidation of the SiO_(x)C_(y)H_(z)nanoparticle coating and the increase in its silica-like structure,the wetting area of the Ar/O_(2)/TMCTS-treated separator was still over 14-fold larger than that of the original separator after aging for 90 days.This study demonstrates an eco-friendly and scalable approach for fabricating high-performance battery separators and provides mechanistic insights into durable wettability by APP.展开更多
The growing demand for renewable energy has increased the use of wood pellets as a clean and efficient biomass fuel.This study aims to evaluate the physical properties of wood pellets produced from Acacia hybrid(AC)ve...The growing demand for renewable energy has increased the use of wood pellets as a clean and efficient biomass fuel.This study aims to evaluate the physical properties of wood pellets produced from Acacia hybrid(AC)veneer waste and Pine wood(PW)waste mixed with varying ratios.The objectives are to investigate the effect of different blend ratios ofAcacia hybrid veneer waste and pine wood waste on the physical properties,specificallymoisture content,density,and pellet durability index(PDI)of wood pellets,and to identify the optimal ratio that yields the most desirable pellet quality.The wood pellets were produced by blending Acacia hybrid veneer waste and Pine wood waste(AC:PW)in weight ratios of 100:0,75:25,50:50,25:75,and 0:100.The materials were dried to 10%–12%moisture before pelletizing using a pellet mill under consistent pressure and temperature.Moisture content(MC),density(ρ)and pellet durability index(PDI)were measured following the International Organization for Standardization(ISO).The study found that blending Acacia hybrid veneer waste with Pine wood waste significantly improved pellet density and durability compared to the control.The moisture was lowest in pellets with 50:50 and 25:75 blends,indicating better drying and stability.The blend 50:50 achieves the highest density,and for pellet durability index,the best blend is 25:75,suggesting improved resistance to breakage.Overall,the 50:50 and 25:75 ratios produced pellet with the most desirable combination of low moisture,high density,high durability and the blend meets key ISO 17225 and ENplus quality standards for industrial wood pellet.展开更多
The excessive use of pesticides has exacerbated environmental pollution due to herbicide residues,while their persistent toxicity poses serious challenges to global ecological security.A magnetically recyclable CoFe_(...The excessive use of pesticides has exacerbated environmental pollution due to herbicide residues,while their persistent toxicity poses serious challenges to global ecological security.A magnetically recyclable CoFe_(2)O_(4)/BiOBr S-scheme heterojunctions was prepared by microwave-assisted co-precipitation method for photocatalytic degradation of Diuron(DUR) in water.The formation of S-scheme heterojunction enhances electron transfer and charge separation,which was demonstrated by free radical trapping,electrochemical experiments,and DFT calculations.The magnetic CoFe_(2)O_(4)/BiOBr catalysts can achieve 99.9 %removal of diuron in 50 min under visible light irradiation.Furthermore,the system maintains stable performance across a broad p H range(3-9),enabling adaptation to diverse water environments,effective elimination of multiple pollutants,and strong resistance to ionic interference.Using magnetic recovery,CoFe_(2)O_(4)/BiOBr exhibits a high removal rate of 99 % and a markedly low ion leaching rate(<20 μg/L) after six cycles photocatalytic process,confirming its excellent stability and durability.According to HPLCQTOF-MS and DFT calculation,the main ways of DUR degradation include dechlorinated hydroxylation,dealkylation and hydroxylation of aromatic ring and side chain.Toxicity analysis showed that the toxicity of the intermediates generated during degradation was generally lower than that of DUR.The magnetic CoFe_(2)O_(4)/BiOBr S-scheme heterojunction developed in this study exhibits excellent photocatalytic performance,high applicability,good stability,and durability,providing an effective magnetic for the removal of refractory pollutants.展开更多
Zinc-iodine(Zn-I_(2))batteries are deemed as potential candidate of energy storage system for the merits of high safety,cost-effectiveness,high capacity,and environmental compatibility.Unfortunately,the practical impl...Zinc-iodine(Zn-I_(2))batteries are deemed as potential candidate of energy storage system for the merits of high safety,cost-effectiveness,high capacity,and environmental compatibility.Unfortunately,the practical implementation of Zn-I_(2)batteries is still hindered by the sluggish iodine redox kinetics and the shuttle effect of soluble polyiodides,which induce rapid capacity decay and electrode interface passivation.This work proposes platinum/carbon(Pt/C)and iridium/carbon(Ir/C)composite as conductive catalytic iodine hosts,which realizes the physical confinement for active iodine through the intrinsic porous structure.The introduction of active Pt/Ir sites effectively anchors the polyiodides through chemical adsorption capability,and inhibits shuttle effect and Zn metal corrosion.In addition,the superior electrical conductivity and catalytic activity of Pt/C and Ir/C carriers also contribute to reduce the reaction energy barriers,significantly promoting the electrochemical performance and conversion reaction kinetics.As expected,the assembled Zn//Pt/C@I_(2)and Zn//Ir/C@I_(2)batteries achieve impressive reversible capacity of 132.2 and 108 mAh g^(-1)after 2000 cycles at 200 mA g^(-1),respectively,and their capacity retention rate after 25000 cycles at 1000 mA g^(-1)are as high as 88.1%and 85.9%.This study will guide the carrier design of iodine cathode to drive the application of high-performance Zn-I2batteries.展开更多
Reducing high overpotentials in the alkaline water reduction reaction is critical for renewable hydrogen storage.Here,we report a dual-site catalytic center comprising oxygen-bridging Fe^(-)OH and Ni-O(FeOHO-NiO)with ...Reducing high overpotentials in the alkaline water reduction reaction is critical for renewable hydrogen storage.Here,we report a dual-site catalytic center comprising oxygen-bridging Fe^(-)OH and Ni-O(FeOHO-NiO)with Pt-like activity,where frustrated Fe^(-)OH Lewis acid and Ni-O Lewis base generate a strong electrostatic field to promote water dissociation(Volmer step:H_(2)O+e^(-)→H_(ad)^(*)+OH^(-)).The resulting H_(ad)^(*)adsorbs on Ni-O,forming Ni-OH_(ad),while Fe^(-)OH and Ni-OH_(ad) synergistically drive the Heyrovsky step(H_(ad)^(*)+H_(2)O+e^(-)→^(*)H_(2)+OH^(-))to produce H_(2).This process achieves ultralow overpotential(52 mV@10 mA cm^(-2))and exceptional stability(>1000 h@300 mA cm^(-2)),offering a design strategy for low-cost and high-performance hydrogen evolution reaction catalysts.展开更多
Polymer nanocomposite coatings(PNCCs)are unprecedented generation of coatings engineered for displaying inexpensive and brilliant functional surface coatings with eminent corrosion guard,mechanical resistance,antimicr...Polymer nanocomposite coatings(PNCCs)are unprecedented generation of coatings engineered for displaying inexpensive and brilliant functional surface coatings with eminent corrosion guard,mechanical resistance,antimicrobial,chemical durability,electrical insulation,and UV aging features.Due to their widely anticipation in petroleum,applications in building,conveyance,aerospace,electronics,automobiles and energy,these multi-functional coatings have a tremendous leverage in human life,all technological and scientific subjects.Numerous applications have been made for multilateral polymers like polyurethane(PU),epoxy(EP),polyaniline(PANI)conductive polymer,polypyrrole(PPy),and etc,on various metallic surfaces especially,carbon steel substrate owing to their excellent resistance properties.Practically,nanomaterials can possess potential in the all-interdisciplinary domains of materials science and engineering,chemical and physical sciences,biological and health sciences.As known,the designed polymer nanocomposite coating paradigm is fundamentally constituted from polymer or resin as a vehicle and inorganic nanofillers(nanoparticles and nanocomposites).Some commercialized and excessively employed nanocontainers in polymer nanocomposite coating formulations,like ZnO,TiO_(2),carbon nanotubes(CNTs),clay,SiO_(2),Al_(2)O_(3),graphene,GO,CeO_(2),ZrO_(2),FeTiO_(3),etc were discussed.The current review covered the chemistry and potential applications of the largest utilized multifunctional polymer nanocomposite coatings such as EP,PU and other considerable PNCCs.Lately,a titanic attention was made for epoxy nanocomposites because of their distinct physicochemical characteristics,which result from the combined qualities of the nanoparticles and polymer material unity.In addition,the author incorporated some of his scientific contributions in this area represented in construction of innovative functional polymer nanocomposites for a variety of uses with high economic,industrial impacts and future orientation.Furthermore,some newly published applications of polymer nanocomposite coatings were incorporated and discussed.展开更多
The utilization of solar-driven interfacial evaporation technology is highly important in addressing the energy crisis and water scarcity,primarily because of its affordability and minimal energy usage.Enhancing the p...The utilization of solar-driven interfacial evaporation technology is highly important in addressing the energy crisis and water scarcity,primarily because of its affordability and minimal energy usage.Enhancing the performance of solar energy evaporation and minimizing material degradation during application can be achieved through the design of novel photothermal materials.In solar interfacial evaporation,photothermal materials exhibit a wide range of additional characteristics,but a systematic overview is lacking.This paper encompasses an examination of various categories and principles pertaining to photothermal materials,as well as the structural design considerations for salt-resistant materials.Additionally,we discuss the versatile uses of this appealing technology in different sectors related to energy and the environment.Furthermore,potential solutions to enhance the durability of photothermal materials are also highlighted,such as the rational design of micro/nano-structures,the use of adhesives,the addition of anti-corrosion coatings,and the preparation of self-healing surfaces.The objective of this review is to offer a viable resolution for the logical creation of high-performance photothermal substances,presenting a guide for the forthcoming advancement of solar evaporation technology.展开更多
This study investigates the use of a low-carbon soil stabilizer called SDG,which is made up of granulated blast furnace slag (GGBFS),desulfurization gypsum (DG),and calcium carbide slag (CCS),to solidify the soil.The ...This study investigates the use of a low-carbon soil stabilizer called SDG,which is made up of granulated blast furnace slag (GGBFS),desulfurization gypsum (DG),and calcium carbide slag (CCS),to solidify the soil.The impact of SDG components on the strength and durability of solidified soil was analysed through a series of tests,including unconfined compressive strength,water stability coefficient,water absorption rate,drying-wetting cycles,and shrinkage tests.Furthermore,microstructure characteristics were analysed using X-ray diffraction (XRD) and scanning electron microscopy (SEM).The study shows that the solidified soil has excellent strength and durability when the SDG stabilizer contains 60% GGBGS,10% DG,and 30% CCS.Additionally,increasing the DG content negatively affects the soil's resistance to water.The SDG stabilizer has potential chemical cementitious characteristics and the calcium carbide slag is rich in calcium ions,which undergo an ion exchange reaction with minerals in the soil.These findings offer new ideas for the development of soil stabilizers.展开更多
Nitrogen-doped single-walled carbon nanohorns(N-SWCNHs)can serve as an effective carrier for platinum(Pt)catalysts,which has the potential to improve the electrocatalytic activity of oxygen reduction reaction(ORR)and ...Nitrogen-doped single-walled carbon nanohorns(N-SWCNHs)can serve as an effective carrier for platinum(Pt)catalysts,which has the potential to improve the electrocatalytic activity of oxygen reduction reaction(ORR)and the operation life of the catalyst.In this work,dahlia-like SWCNHs with N contents ranging from 2.1at%to 4.3at%are controllably synthesized via arc discharge and applied as a carrier of Pt nanoparticles(NPs),denoted as Pt/N-SWCNHs.Pt/N-SWCNHs-2:1(graphite and melamine with the mass ratio of 2:1)exhibits excellent electrocatalytic activity(onset potential=0.95 V).The half-wave potential of Pt/N-SWCNHs-2:1 is only reduced by 2 mV after 3000 cyclic voltammetry cycles.This can be attributed to the enhanced dispersion of Pt NPs and the strong electronic interaction between the N-SWCNHs and Pt,facilitated by the optimal nitrogen doping level.The results of this work offer important perspectives on the design and enhancement of Pt-based electrocatalysts for ORR applications,highlighting the critical role of the nitrogen doping level in balancing the electrocatalytic activity and long-term stability.展开更多
This paper provides a comprehensive review of various experimental methods used to study carbon corrosion in automotive polymer exchange membrane fuel cells.Quantifying the extent of carbon corrosion is essential for ...This paper provides a comprehensive review of various experimental methods used to study carbon corrosion in automotive polymer exchange membrane fuel cells.Quantifying the extent of carbon corrosion is essential for advancing the technology and implementing effective mitigation strategies.While studying degradation events directly within a real-world fuel cell vehicle offers the most reliable insights,the high costs and time demands make it necessary to develop specialised experimental techniques that provide high-resolution data more efficiently and cost-effectively.This review explores the various experimental approaches utilised in automotive application induced carbon corrosion studies globally,including load profiles,test setups,break-in procedures,and cell recovery protocols.In this paper,emphasis is placed on the standardised procedures proposed by leading institutions worldwide,accompanied by critical discussions on these protocols.Furthermore,the paper highlights modified or innovative procedures developed by smaller institutions,universities,and individual researchers,thereby offering a comprehensive overview essential for carbon corrosion analysis.The review also discusses the fundamental principles,benefits,and limitations of various procedures,offering guidance on selecting the most appropriate approach for a given study.Lastly,it addresses the limitations within the current body of literature and outlines potential future prospects.展开更多
Maintaining the integrity and longevity of structures is essential in many industries,such as aerospace,nuclear,and petroleum.To achieve the cost-effectiveness of large-scale systems in petroleum drilling,a strong emp...Maintaining the integrity and longevity of structures is essential in many industries,such as aerospace,nuclear,and petroleum.To achieve the cost-effectiveness of large-scale systems in petroleum drilling,a strong emphasis on structural durability and monitoring is required.This study focuses on the mechanical vibrations that occur in rotary drilling systems,which have a substantial impact on the structural integrity of drilling equipment.The study specifically investigates axial,torsional,and lateral vibrations,which might lead to negative consequences such as bit-bounce,chaotic whirling,and high-frequency stick-slip.These events not only hinder the efficiency of drilling but also lead to exhaustion and harm to the system’s components since they are difficult to be detected and controlled in real time.The study investigates the dynamic interactions of these vibrations,specifically in their high-frequency modes,usingfield data obtained from measurement while drilling.Thefindings have demonstrated the effect of strong coupling between the high-frequency modes of these vibrations on drilling sys-tem performance.The obtained results highlight the importance of considering the interconnected impacts of these vibrations when designing and implementing robust control systems.Therefore,integrating these compo-nents can increase the durability of drill bits and drill strings,as well as improve the ability to monitor and detect damage.Moreover,by exploiting thesefindings,the assessment of structural resilience in rotary drilling systems can be enhanced.Furthermore,the study demonstrates the capacity of structural health monitoring to improve the quality,dependability,and efficiency of rotary drilling systems in the petroleum industry.展开更多
基金National Natural Science Foundation of China(Grant No.52273060)Science and Technology Research Project of the Educational Commission of Hubei Province(Grant No.D20221703)provide financial support.
文摘The antibacterial polyamide 6(PA6)material has attracted great research interest due to its wide ap-plication in food packaging,biomedical fields,functional textiles,and other fields.However,it is still a challenge to prepare intrinsically antibacterial PA6 with highly efficient and durably antibacterial activity via polymerization.Herein,the antibacterial imidazolium ionic liquid of 3-carboxymethyl-1-decyl imida-zole chloride was designed and synthesized for adapting the polymerization and processing temperature of PA6.Then antibacterial PA6(PA6-IL)was synthesized through hydrolyzed ring-opening copolymeriza-tion with imidazolium at the end of the backbones.Compared to physical blending or post-modification methods,antibacterial agents as end-capping reagents of polymer backbones endowed PA6 with intrin-sic antibacterial activity.As expected,the obtained PA6-IL exhibited not just comparable physicochemical and mechanical properties to conventional PA6 but excellent antibacterial activity of low antibacterial time to 60 min and durability for 28 days.Additionally,the corresponding electrospun PA6-IL nanofi-brous membranes showed homogenous morphology and remarkable hydrophilicity of 7.7° as well as the high-efficient antibacterial activity.Melt-spun PA6-IL microfibers revealed a smooth surface as well as enhanced tensile strength and increased breaking elongation compared to those of conventional PA6.The PA6-IL microfibers also behaved with excellent antibacterial efficiency and durability.Accordingly,this work provides a feasible and straightforward strategy to prepare durably and intrinsically antibacterial PA6 materials especially PA6 fibers,which can be widely applied in the textiles field.
文摘A new fertilizer of cocrystal type,known as durably efficacious ammonium bicarbonate(DEAB),has been developed by adding a certain amount of dicyandiamide(DCD)as an ammonia-stabilizing agent to ammonium bearbenate(AB)during the process of its production.As compared with AB,DEAB was found to have a reduction of direct volatilization loss by 53%,a fertilizer availability period prolonged from 35-45 to 90-110 d,and an increase in the rate of nitrogen in fertilizer being utilized by 5.9%-10.2%,and a saving of the amount of fertilizer to be ap-phed by 20%-30%for the same level of yield,or an increase of the crop yield by over 10%for the same level of ni-tregen fertilization;in addition,it was found to show usually a function of promoting the crop to early mature.It can be applied as basal dressing all in one time to soil and thus also used as a labour-saving and crop yield-increasing fertil-izer for is non-mtertillage,plastics film covering and water-saving agriculture.
基金supported by the Natural Science Foundation of Chongqing(Grant No.CSTB2024NSCQMSX0440)the National Key R&D Project from Minister of Science and Technology(2021YFA1201602)+2 种基金the Science and Technology Research Program of Chongqing Municipal Education Commission(Grant No.KJQN202400506)the Doctor Scientific Research Fund of Chongqing Normal University(Grant No.23XLB017)the Technology Research Program of Chongqing Municipal Education Commission(Grant No.KJZD-K202200505)。
文摘Improving the electric output and durability of triboelectric nanogenerator(TENG)remains a great challenge.In sliding-mode TENG,surface charge dissipation and charge leakage caused by the volume effect result in serious energy waste.In this work,a durable dual output mode TENG(DDO-TENG),which includes alteranting current and direct current output modes,is designed to capture the dissipating charges in the surface of charge space accumulation area and the inner leakage charge in porous network to further improve the output performance of sliding TENGs.The output charge density of DDO-TENG reaches 0.847 mC m^(-2),which is 2.39 times as that of the single mode device.In addition,it has strong durability,remaining 95.7%after over 271 k cycles,and it can continuously power electronics by harvesting wind energy.This work provides a strategy for achieving the improvement on output performance and durability and expands the application of TENG.
基金Funded by the Science and Technology Program of Gansu Province(Nos.25JRRA497,23ZDFA017)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB0950000)High-level Talent Funding of Kashi。
文摘This study introduces superabsorbent polymers(SAP)into recycled concrete and,through freeze-thaw cycle tests,unconfined compressive strength tests,and nuclear magnetic resonance(NMR)analysis,evaluates the freeze-thaw resistance and durability of recycled concrete samples under varying freeze-thaw cycles.The results indicate that an appropriate addition of SAP significantly enhances the freeze-thaw resistance of recycled concrete.After 200 freeze-thaw cycles,the RS0.6 sample retained good surface integrity,demonstrating the best performance.Compared to NAC,its mass loss decreased by 1.16%,the relative dynamic modulus improved by 7.01%,and the compressive strength loss rate decreased by 5.41%.Additionally,T2 spectrum analysis revealed that adding SAP optimized the pore structure of recycled concrete and mitigated pore development during freeze-thaw cycles.As the number of freeze-thaw cycles increased,the RS0.3 and RS0.6 samples demonstrated superior frost resistance compared to NAC.However,an excessive amount of SAP increased pore expansion during subsequent freeze-thaw cycles,ultimately weakening frost resistance.
文摘Concrete lining slabs of long-distance water conveyance projects in northern China are susceptible to freeze-thaw erosion,which places higher requirements on the performance of repair materials for eroded areas,such as frost resistance,adhesion,coating penetration depth,water absorption ratio,and durability.Performance tests were conducted on existing repair materials,and the results showed that:XYPEX exhibits better performance compared to other materials;the high-performance ultra-nano silane impregnant has outstanding performance;and the composite coating demonstrates excellent comprehensive performance.The composite material modified with nano-SiO_(2) has further improved strength and durability.
基金Funded by the 111 Project(No.B17034)Open Project of Hubei Key Laboratory of Power System Design and Test for Electrical Vehicle(No.ZDSYS202212)+1 种基金Innovative Research Team Development Program of Ministry of Education of China(No.IRT_17R83)the Science and Technology Project of China Southern Power Grid Co.,Ltd.(No.GDKJXM20222546)。
文摘The development of Pt-free catalysts for the oxygen reduction reaction(ORR)is a great issue for meeting the cost challenges of proton exchange membrane fuel cells(PEMFCs)in commercial applications.In this work,a series of RuCo/C catalysts were synthesized by NaBH4 reduction method under the premise that the total metal mass percentage was 20%.X-ray diffraction(XRD)patterns and scanning electron microscopy(SEM)confirmed the formation of single-phase nanoparticles with an average size of 33 nm.Cyclic voltammograms(CV)and linear sweep voltammograms(LSV)tests indicated that RuCo(2:1)/C catalyst had the optimal ORR properties.Additionally,the RuCo(2:1)/C catalyst remarkably sustained 98.1% of its activity even after 3000 cycles,surpassing the performance of Pt/C(84.8%).Analysis of the elemental state of the catalyst surface after cycling using X-ray photoelectron spectroscopy(XPS)revealed that the Ru^(0) percentage of RuCo(2:1)/C decreased by 2.2%(from 66.3% to 64.1%),while the Pt^(0) percentage of Pt/C decreased by 7.1%(from 53.3% to 46.2%).It is suggested that the synergy between Ru and Co holds the potential to pave the way for future low-cost and highly stable ORR catalysts,offering significant promise in the context of PEMFCs.
基金supported by the National Natural Science Foundation of China(Grant Nos.42525201 and 42230710).
文摘Bio-carbonation of reactive MgO has been regarded as a promising and eco-friendly method for construction and demolition waste(CDW)cementation in various geotechnical engineering applications.However,the beneficial effect of bio-carbonation of reactive MgO cemented CDW(BCM-samples)can be altered when exposed to wetting-drying cycles induced by extreme climate changes or groundwater fluctuations.To better understand the durability of BCM-samples and their underlying deterioration mechanisms,a series of BCM-samples was prepared to investigate their physical-mechanical performance and microstructure evolution subjected to the wetting-drying cycles.The results indicated that the wetting-drying cycles can deteriorate the BCM-samples,and their physical-mechanical behaviors change quickly at the cycle beginning and then smoothly after 2 cycles.With the increase in cycling,the apparent deterioration with efflorescence and microcrack development can be observed.The mass loss and water absorption rates increased while the dry density,compressional wave velocity,and unconfined compression strength decreased.Urea pre-hydrolysis treatment can significantly improve the durability of BCM-samples,as the more hydrated magnesia carbonates(HMCs)enhance the cementing effects.After 10 cycles,the UCS of pre-hydrolyzed samples decreased 25.4%to 4.45 MPa,while that of ordinary samples decreased 50.7%to 1.20 MPa.The deterioration of BCM-samples caused by wetting-drying cycles can be attributed to two factors.One of the main factors is the structural integrity changes caused by the rapid loss of soluble material at the initial cycling stages.Another factor is the decrease in cementation induced by the loss of brucite and HMCs at the following cycle stages.
基金Funded by the National Natural Science Foundation of China(No.52178216)the Research on the Durability and Application of High-performance Concrete for Highway Engineering in the Cold and Arid Salt Areas of Northwest China(No.2022-24)the Construction Project of the Scientific Research Platform of Provincial Enterprises Supported by the Capital Operating Budget of Gansu Province(No.2023GZ018)。
文摘To study the durability of concrete in harsh environments in Northwest China,concrete was prepared with various durability-improving materials such as concrete anti-erosion inhibitor(SBT-TIA),acrylate polymer(AP),super absorbent resin(SAP).The erosion mode and internal deterioration mechanism under salt freeze-thaw cycle and dry-wet cycle were explored.The results show that the addition of enhancing materials can effectively improve the resistance of concrete to salt freezing and sulfate erosion:the relevant indexes of concrete added with X-AP and T-AP are improved after salt freeze-thaw cycles;concrete added with SBTTIA shows optimal sulfate corrosion resistance;and concrete added with AP displays the best resistance to salt freezing.Microanalysis shows that the increase in the number of cycles decreases the generation of internal hydration products and defects in concrete mixed with enhancing materials and improves the related indexes.Based on the Wiener model analysis,the reliability of concrete with different lithologies and enhancing materials is improved,which may provide a reference for the application of manufactured sand concrete and enhancing materials in Northwest China,especially for the study of the improvement effects and mechanism of enhancing materials on the performance of concrete.
文摘1.Introduction.Pancreaticoduodenectomy is an essential surgical procedure for the treatment of malignant tumors in the pancreatic head,distal common bile duct,and duodenal papilla,and is widely used in clinical practice.One of the primary determinants of surgical success is the durability of the pancreaticojejunal anastomosis.
基金supported by the National Natural Science Foundation of China(No.12075054)the Fundamental Research Funds for the Central Universities(No.CUSF-DH-T-2024069)。
文摘The rapid decay of the surface wettability of plasma-treated polymers remains a critical limitation for their practical application in advanced materials.This study introduces a continuous atmospheric pressure plasma(APP)technique for fabricating polyethylene(PE)separators with durable wettability,and elucidates the underlying mechanism.A systematic comparison of APP treatments with non-deposition and deposition gases,including Ar,Ar/O_(2),Ar/tetramethylcyclotetrasiloxane(TMCTS),and Ar/O_(2)/TMCTS,revealed the key impact factors in achieving durable wettability.Owing to the synergistic interactions of SiO_(x)C_(y)H_(z)nanoparticulate deposition,physical etching,and oxidative functionalization,the PE separator treated by Ar/O_(2)/TMCTS exhibited a 17.5-fold electrolyte wetting area compared to the original one.The improved surface energy and roughness of the SiO_(x)C_(y)H_(z)nanoparticle coating enhanced its electrochemical performance.The ionic conductivity increased by 1.9 times,while the charge transfer resistance decreased by 73.7%.Remarkably,owing to further oxidation of the SiO_(x)C_(y)H_(z)nanoparticle coating and the increase in its silica-like structure,the wetting area of the Ar/O_(2)/TMCTS-treated separator was still over 14-fold larger than that of the original separator after aging for 90 days.This study demonstrates an eco-friendly and scalable approach for fabricating high-performance battery separators and provides mechanistic insights into durable wettability by APP.
基金the financial support provided by UMS Great(GUG0670-1/2024),which played a crucial role in the completion of this studyAdditionally,we would like to express our sincere appreciation for the financial assistance and scholarships generously offered by the University of Malaysia Sabah(UMS)throughout the Ministry of Higher Education Malaysia(KPT)throughout the research period.These contributions were invaluable in facilitating our research endeavors.
文摘The growing demand for renewable energy has increased the use of wood pellets as a clean and efficient biomass fuel.This study aims to evaluate the physical properties of wood pellets produced from Acacia hybrid(AC)veneer waste and Pine wood(PW)waste mixed with varying ratios.The objectives are to investigate the effect of different blend ratios ofAcacia hybrid veneer waste and pine wood waste on the physical properties,specificallymoisture content,density,and pellet durability index(PDI)of wood pellets,and to identify the optimal ratio that yields the most desirable pellet quality.The wood pellets were produced by blending Acacia hybrid veneer waste and Pine wood waste(AC:PW)in weight ratios of 100:0,75:25,50:50,25:75,and 0:100.The materials were dried to 10%–12%moisture before pelletizing using a pellet mill under consistent pressure and temperature.Moisture content(MC),density(ρ)and pellet durability index(PDI)were measured following the International Organization for Standardization(ISO).The study found that blending Acacia hybrid veneer waste with Pine wood waste significantly improved pellet density and durability compared to the control.The moisture was lowest in pellets with 50:50 and 25:75 blends,indicating better drying and stability.The blend 50:50 achieves the highest density,and for pellet durability index,the best blend is 25:75,suggesting improved resistance to breakage.Overall,the 50:50 and 25:75 ratios produced pellet with the most desirable combination of low moisture,high density,high durability and the blend meets key ISO 17225 and ENplus quality standards for industrial wood pellet.
基金supported by the National Natural Science Foundation of China (No.52370174)the Natural Science Foundation of Shandong Province,China (No.ZR2022ME128)Special Projects in Key Areas of Colleges and Universities in Guangdong Province (No.2023ZDZX4050)。
文摘The excessive use of pesticides has exacerbated environmental pollution due to herbicide residues,while their persistent toxicity poses serious challenges to global ecological security.A magnetically recyclable CoFe_(2)O_(4)/BiOBr S-scheme heterojunctions was prepared by microwave-assisted co-precipitation method for photocatalytic degradation of Diuron(DUR) in water.The formation of S-scheme heterojunction enhances electron transfer and charge separation,which was demonstrated by free radical trapping,electrochemical experiments,and DFT calculations.The magnetic CoFe_(2)O_(4)/BiOBr catalysts can achieve 99.9 %removal of diuron in 50 min under visible light irradiation.Furthermore,the system maintains stable performance across a broad p H range(3-9),enabling adaptation to diverse water environments,effective elimination of multiple pollutants,and strong resistance to ionic interference.Using magnetic recovery,CoFe_(2)O_(4)/BiOBr exhibits a high removal rate of 99 % and a markedly low ion leaching rate(<20 μg/L) after six cycles photocatalytic process,confirming its excellent stability and durability.According to HPLCQTOF-MS and DFT calculation,the main ways of DUR degradation include dechlorinated hydroxylation,dealkylation and hydroxylation of aromatic ring and side chain.Toxicity analysis showed that the toxicity of the intermediates generated during degradation was generally lower than that of DUR.The magnetic CoFe_(2)O_(4)/BiOBr S-scheme heterojunction developed in this study exhibits excellent photocatalytic performance,high applicability,good stability,and durability,providing an effective magnetic for the removal of refractory pollutants.
基金the National Natural Science Foundation of China(Nos.52404316,52461040,52274297,52474325,and 22202053)Hainan Provincial Natural Science Foundation(No.524RC475)+3 种基金Collaborative Innovation Center of Marine Science and Technology of Hainan University(No.XTCX2022HYC14)Start-up Research Foundation of Hainan University(Nos.XJ2400012968,KYQD(ZR)23069,23169 and 21124the support for comprehensive characterizations by Pico Election Microscopy Center of Hainan Universitythe funding supports from China Scholarship Council。
文摘Zinc-iodine(Zn-I_(2))batteries are deemed as potential candidate of energy storage system for the merits of high safety,cost-effectiveness,high capacity,and environmental compatibility.Unfortunately,the practical implementation of Zn-I_(2)batteries is still hindered by the sluggish iodine redox kinetics and the shuttle effect of soluble polyiodides,which induce rapid capacity decay and electrode interface passivation.This work proposes platinum/carbon(Pt/C)and iridium/carbon(Ir/C)composite as conductive catalytic iodine hosts,which realizes the physical confinement for active iodine through the intrinsic porous structure.The introduction of active Pt/Ir sites effectively anchors the polyiodides through chemical adsorption capability,and inhibits shuttle effect and Zn metal corrosion.In addition,the superior electrical conductivity and catalytic activity of Pt/C and Ir/C carriers also contribute to reduce the reaction energy barriers,significantly promoting the electrochemical performance and conversion reaction kinetics.As expected,the assembled Zn//Pt/C@I_(2)and Zn//Ir/C@I_(2)batteries achieve impressive reversible capacity of 132.2 and 108 mAh g^(-1)after 2000 cycles at 200 mA g^(-1),respectively,and their capacity retention rate after 25000 cycles at 1000 mA g^(-1)are as high as 88.1%and 85.9%.This study will guide the carrier design of iodine cathode to drive the application of high-performance Zn-I2batteries.
基金supported primarily by the Scientific and Technological Innovation Project of Carbon Emission Peak and Carbon Neutrality of Jiangsu Province(No.BE2022028-1)the National Natural Science Foundation of China(Grant Nos 52272217,51872135,22372078,51572121,and 21633004)。
文摘Reducing high overpotentials in the alkaline water reduction reaction is critical for renewable hydrogen storage.Here,we report a dual-site catalytic center comprising oxygen-bridging Fe^(-)OH and Ni-O(FeOHO-NiO)with Pt-like activity,where frustrated Fe^(-)OH Lewis acid and Ni-O Lewis base generate a strong electrostatic field to promote water dissociation(Volmer step:H_(2)O+e^(-)→H_(ad)^(*)+OH^(-)).The resulting H_(ad)^(*)adsorbs on Ni-O,forming Ni-OH_(ad),while Fe^(-)OH and Ni-OH_(ad) synergistically drive the Heyrovsky step(H_(ad)^(*)+H_(2)O+e^(-)→^(*)H_(2)+OH^(-))to produce H_(2).This process achieves ultralow overpotential(52 mV@10 mA cm^(-2))and exceptional stability(>1000 h@300 mA cm^(-2)),offering a design strategy for low-cost and high-performance hydrogen evolution reaction catalysts.
文摘Polymer nanocomposite coatings(PNCCs)are unprecedented generation of coatings engineered for displaying inexpensive and brilliant functional surface coatings with eminent corrosion guard,mechanical resistance,antimicrobial,chemical durability,electrical insulation,and UV aging features.Due to their widely anticipation in petroleum,applications in building,conveyance,aerospace,electronics,automobiles and energy,these multi-functional coatings have a tremendous leverage in human life,all technological and scientific subjects.Numerous applications have been made for multilateral polymers like polyurethane(PU),epoxy(EP),polyaniline(PANI)conductive polymer,polypyrrole(PPy),and etc,on various metallic surfaces especially,carbon steel substrate owing to their excellent resistance properties.Practically,nanomaterials can possess potential in the all-interdisciplinary domains of materials science and engineering,chemical and physical sciences,biological and health sciences.As known,the designed polymer nanocomposite coating paradigm is fundamentally constituted from polymer or resin as a vehicle and inorganic nanofillers(nanoparticles and nanocomposites).Some commercialized and excessively employed nanocontainers in polymer nanocomposite coating formulations,like ZnO,TiO_(2),carbon nanotubes(CNTs),clay,SiO_(2),Al_(2)O_(3),graphene,GO,CeO_(2),ZrO_(2),FeTiO_(3),etc were discussed.The current review covered the chemistry and potential applications of the largest utilized multifunctional polymer nanocomposite coatings such as EP,PU and other considerable PNCCs.Lately,a titanic attention was made for epoxy nanocomposites because of their distinct physicochemical characteristics,which result from the combined qualities of the nanoparticles and polymer material unity.In addition,the author incorporated some of his scientific contributions in this area represented in construction of innovative functional polymer nanocomposites for a variety of uses with high economic,industrial impacts and future orientation.Furthermore,some newly published applications of polymer nanocomposite coatings were incorporated and discussed.
基金supported by Zhejiang Provincial Natural Science Foundation of China(No.LR23C160001)Scientific Research Startup Foundation of Zhejiang Ocean University(No.11034150220006).
文摘The utilization of solar-driven interfacial evaporation technology is highly important in addressing the energy crisis and water scarcity,primarily because of its affordability and minimal energy usage.Enhancing the performance of solar energy evaporation and minimizing material degradation during application can be achieved through the design of novel photothermal materials.In solar interfacial evaporation,photothermal materials exhibit a wide range of additional characteristics,but a systematic overview is lacking.This paper encompasses an examination of various categories and principles pertaining to photothermal materials,as well as the structural design considerations for salt-resistant materials.Additionally,we discuss the versatile uses of this appealing technology in different sectors related to energy and the environment.Furthermore,potential solutions to enhance the durability of photothermal materials are also highlighted,such as the rational design of micro/nano-structures,the use of adhesives,the addition of anti-corrosion coatings,and the preparation of self-healing surfaces.The objective of this review is to offer a viable resolution for the logical creation of high-performance photothermal substances,presenting a guide for the forthcoming advancement of solar evaporation technology.
基金Funded by the National Key R&D Program of China (No. 2022YFC3803405)the China State Construction Key Laboratory Project (No. ZJXJ-PT-2022-14)。
文摘This study investigates the use of a low-carbon soil stabilizer called SDG,which is made up of granulated blast furnace slag (GGBFS),desulfurization gypsum (DG),and calcium carbide slag (CCS),to solidify the soil.The impact of SDG components on the strength and durability of solidified soil was analysed through a series of tests,including unconfined compressive strength,water stability coefficient,water absorption rate,drying-wetting cycles,and shrinkage tests.Furthermore,microstructure characteristics were analysed using X-ray diffraction (XRD) and scanning electron microscopy (SEM).The study shows that the solidified soil has excellent strength and durability when the SDG stabilizer contains 60% GGBGS,10% DG,and 30% CCS.Additionally,increasing the DG content negatively affects the soil's resistance to water.The SDG stabilizer has potential chemical cementitious characteristics and the calcium carbide slag is rich in calcium ions,which undergo an ion exchange reaction with minerals in the soil.These findings offer new ideas for the development of soil stabilizers.
基金financially supported by the National Natural Science Foundation of China(Nos.12175089 and 12205127)the Key Research and Development Program of Yunnan Province,China(Nos.202301AU070064 and 202103AF140006)the Yunnan Industrial Innovative Talents Program for“Xingdian Talent Support Plan”,China(No.KKXY202252001).
文摘Nitrogen-doped single-walled carbon nanohorns(N-SWCNHs)can serve as an effective carrier for platinum(Pt)catalysts,which has the potential to improve the electrocatalytic activity of oxygen reduction reaction(ORR)and the operation life of the catalyst.In this work,dahlia-like SWCNHs with N contents ranging from 2.1at%to 4.3at%are controllably synthesized via arc discharge and applied as a carrier of Pt nanoparticles(NPs),denoted as Pt/N-SWCNHs.Pt/N-SWCNHs-2:1(graphite and melamine with the mass ratio of 2:1)exhibits excellent electrocatalytic activity(onset potential=0.95 V).The half-wave potential of Pt/N-SWCNHs-2:1 is only reduced by 2 mV after 3000 cyclic voltammetry cycles.This can be attributed to the enhanced dispersion of Pt NPs and the strong electronic interaction between the N-SWCNHs and Pt,facilitated by the optimal nitrogen doping level.The results of this work offer important perspectives on the design and enhancement of Pt-based electrocatalysts for ORR applications,highlighting the critical role of the nitrogen doping level in balancing the electrocatalytic activity and long-term stability.
文摘This paper provides a comprehensive review of various experimental methods used to study carbon corrosion in automotive polymer exchange membrane fuel cells.Quantifying the extent of carbon corrosion is essential for advancing the technology and implementing effective mitigation strategies.While studying degradation events directly within a real-world fuel cell vehicle offers the most reliable insights,the high costs and time demands make it necessary to develop specialised experimental techniques that provide high-resolution data more efficiently and cost-effectively.This review explores the various experimental approaches utilised in automotive application induced carbon corrosion studies globally,including load profiles,test setups,break-in procedures,and cell recovery protocols.In this paper,emphasis is placed on the standardised procedures proposed by leading institutions worldwide,accompanied by critical discussions on these protocols.Furthermore,the paper highlights modified or innovative procedures developed by smaller institutions,universities,and individual researchers,thereby offering a comprehensive overview essential for carbon corrosion analysis.The review also discusses the fundamental principles,benefits,and limitations of various procedures,offering guidance on selecting the most appropriate approach for a given study.Lastly,it addresses the limitations within the current body of literature and outlines potential future prospects.
文摘Maintaining the integrity and longevity of structures is essential in many industries,such as aerospace,nuclear,and petroleum.To achieve the cost-effectiveness of large-scale systems in petroleum drilling,a strong emphasis on structural durability and monitoring is required.This study focuses on the mechanical vibrations that occur in rotary drilling systems,which have a substantial impact on the structural integrity of drilling equipment.The study specifically investigates axial,torsional,and lateral vibrations,which might lead to negative consequences such as bit-bounce,chaotic whirling,and high-frequency stick-slip.These events not only hinder the efficiency of drilling but also lead to exhaustion and harm to the system’s components since they are difficult to be detected and controlled in real time.The study investigates the dynamic interactions of these vibrations,specifically in their high-frequency modes,usingfield data obtained from measurement while drilling.Thefindings have demonstrated the effect of strong coupling between the high-frequency modes of these vibrations on drilling sys-tem performance.The obtained results highlight the importance of considering the interconnected impacts of these vibrations when designing and implementing robust control systems.Therefore,integrating these compo-nents can increase the durability of drill bits and drill strings,as well as improve the ability to monitor and detect damage.Moreover,by exploiting thesefindings,the assessment of structural resilience in rotary drilling systems can be enhanced.Furthermore,the study demonstrates the capacity of structural health monitoring to improve the quality,dependability,and efficiency of rotary drilling systems in the petroleum industry.
