Despite the impressive power conversion efficiency(PCE)beyond 25.5%,perovskite solar cells,especially the Sn-based variants,are poorly stable under normal operating conditions compared with the market-dominant silicon...Despite the impressive power conversion efficiency(PCE)beyond 25.5%,perovskite solar cells,especially the Sn-based variants,are poorly stable under normal operating conditions compared with the market-dominant silicon solar cells that can last for over 25 years.2D3D hybrid perovskite materials are one of the best options to overcome the instability chal-lenge without compromising efficiency.Indeed,a record performance of 1 year was reported in Pb-based 2D3D planar per-ovskite devices.However,the reaction between 2 and 3D perovskite molecules requires high temperatures(-300°C)and increased reaction time(-24 h)to achieve high-quality 2D3D hybrid perovskites.Herein,we base on the ability of chlorine to displace iodine from its ionic compounds in solutions to utilize chloride ions as catalysts for speeding up the reaction between iodine-based 2D and 3D perovskite molecules.The approach reduces the reaction time to-20 min and the reaction temperature to-100°C with the formation of high-quality 2D3D hybrid perovskites,free from pure 2D traces.Integrating the synthesized 2D3D hybrid perovskite material with 50%chlorine doping in a fiber-shaped solar cell architecture yielded the highest reported PCE of 11.96%in Sn-based fiber-shaped perovskite solar cells.The unencapsulated and encapsulated fiber-shaped solar cells could maintain 75%and 95.5%of their original PCE,respectively,after 3 months under room light and relative humidity of 35–40%,revealing the champion stability in Sn-based perovskite solar devices.The solar yarn also demonstrated constant energy output under changing light incident angles(0–180°).展开更多
The introduction of two-dimensional(2D)perovskite layers on top of three-dimensional(3D)perovskite films enhances the performance and stability of perovskite solar cells(PSCs).However,the electronic effect of the spac...The introduction of two-dimensional(2D)perovskite layers on top of three-dimensional(3D)perovskite films enhances the performance and stability of perovskite solar cells(PSCs).However,the electronic effect of the spacer cation and the quality of the 2D capping layer are critical factors in achieving the required results.In this study,we compared two fluorinated salts:4-(trifluoromethyl)benzamidine hydrochloride(4TF-BA·HCl)and 4-fluorobenzamidine hydrochloride(4F-BA·HCl)to engineer the 3D/2D perovskite films.Surprisingly,4F-BA formed a high-performance 3D/2D heterojunction,while4TF-BA produced an amorphous layer on the perovskite films.Our findings indicate that the balanced intramolecular charge polarization,which leads to effective hydrogen bonding,is more favorable in 4F-BA than in 4TF-BA,promoting the formation of a crystalline 2D perovskite.Nevertheless,4TF-BA managed to improve efficiency to 24%,surpassing the control device,primarily due to the natural passivation capabilities of benzamidine.Interestingly,the devices based on 4F-BA demonstrated an efficiency exceeding 25%with greater longevity under various storage conditions compared to 4TF-BA-based and the control devices.展开更多
Herein,a new type of two-dimensional(2D)/2D Ti_(3)C_(2)/TiO_(2) heterojunction was developed for efficient photocatalytic nitrogen reduction reaction(NRR),in which TiO_(2) nanosheets(TiO_(2) Ns)were designed as the ma...Herein,a new type of two-dimensional(2D)/2D Ti_(3)C_(2)/TiO_(2) heterojunction was developed for efficient photocatalytic nitrogen reduction reaction(NRR),in which TiO_(2) nanosheets(TiO_(2) Ns)were designed as the main catalyst,while Ti_(3)C_(2) MXene served as the co-catalyst.Experimental and theoretical results revealed that Ti_(3)C_(2) MXene introduced electron-rich unsaturated Ti sites,serving as highly active sites for both the adsorption and activation of N_(2) on the Ti_(3)C_(2)/TiO_(2) heterojunction.Furthermore,the 2D/2D Ti_(3)C_(2)/TiO_(2) heterostructure greatly promoted the directional separation and transfer of charge carriers,facilitated by the internal electric field.This structural feature enabled the spatial separation of the N_(2) reduction and H2 O oxidation half-reactions on the distinct surfaces of Ti_(3)C_(2)(001)and TiO_(2)(001),con-sequently reducing the reaction energy barrier for each respective process.The synergistic effects arising from the interface and surface interactions within the heterojunction conspicuously improved the photo-catalytic NRR activity.As a result,the optimized Ti_(3)C_(2)/TiO_(2) heterojunction exhibited a high NH_(3) produc-tion rate of 24.4μmol g−1 h−1 in the absence of sacrificial agents,representing a remarkable 12.8-fold increase compared to individual TiO_(2) Ns.This work provides new insights into rational design of high-performance heterogeneous photocatalysts and offers a deeper understanding of the mechanism under-lying surface active sites in the photocatalytic NRR process.展开更多
The geological disasters such as collapse,mud bursting and water gushing often occur during tunnel construction.Thus,it is of great significance to detect the hidden geological disasters ahead of the tunnel face.The a...The geological disasters such as collapse,mud bursting and water gushing often occur during tunnel construction.Thus,it is of great significance to detect the hidden geological disasters ahead of the tunnel face.The audio magnetotelluric(AMT)was applied for the advanced detectionstudy during the boring process of the Tianheshan tunnel in the Taihang Mountains.Three AMT profiles were deployed above the tunnel,and the data obtained in the field were analysed in terms of electrical principal axes.From shallow to deep,the direction of the geoelectric strike angle changes,generally between 30°and 60°NE,which is consistent with similar to the direction of the Taihangshan Uplift,and the data show some 3D characteristics.Two-dimensional(2D)and three-dimensional(3D)inversion methods were adopted to jointly study the subsurface structural information,and the resistivity model was geophysically and geologically interpreted.Two sets of low resistance anomalies were found,and it was hypothesised that the near-erect low-resistivity anomalies in the east might be a fragmentation zone,while the low resistance anomalies in the west,which are inclined to the westward,might be a tectonic structure or fragmentation zone related to the regional major fault,and the results of the tunnelling confirmed the reliability of the inversion interpretation.The 3D inversion can fully reflect the development scale and morphological changes of the fracture zone,and the inversion model is more reliable.Finally,it is concluded that the audio magnetotelluric method,which adopts advanced acquisition,processing and inversion interpretation techniques,is an effective means of over-detection of tunnels.展开更多
The 2D/3D heterojunction perovskites have garnered increasing attention due to their exceptional moisture and thermal stability.However,few works have paid attention to the influence of the subsequent change process o...The 2D/3D heterojunction perovskites have garnered increasing attention due to their exceptional moisture and thermal stability.However,few works have paid attention to the influence of the subsequent change process of 2D/3D heterojunction PSC on the stability of PSCs.Moreover,the evolution of the interface and carrier dynamic behavior of the 2D/3D perovskite films with long-term operation has not been systematically developed befo re.In this work,the effects of 2D/3 D heterojunction evolution on the interface of perovskite films and different carrier dynamics during 2D/3D evolution are systematically analyzed for the first time.The decomposition of 2D/3D heterojunction in the perovskite film will have a certain impact on the surface and carrier dynamics behavior of perovskite.During the evolution of 2D/3D heterojunction,PbI_(2)crystals will appear,which will improve the interfacial energy level matching between the electron transport layer and perovskite film.With a long evolution time,some holes will appear on the surface of perovskite film.The open circuit voltage(V_(OC))of PSCs increased from 1.14 to1.18 V and the PCE increased to 23.21%after 300 h storage in the nitrogen atmosphere,and maintained 89%initial performance for with 3000 h stability test in N_(2)box.This discovery has a significant role in promoting the development of inverted heterojunction PSCs and constructing the revolution mechanism of charge carrier dynamic.展开更多
Perovskite solar cells(PSCs)incorporating 2D/3D heterostructures have exhibited remarkable improvements in both power conversion efficiency and operational stability.Nevertheless,the prevalent spin-coating fabrication...Perovskite solar cells(PSCs)incorporating 2D/3D heterostructures have exhibited remarkable improvements in both power conversion efficiency and operational stability.Nevertheless,the prevalent spin-coating fabrication technique presents formidable challenges for scalable manufacturing processes.Herein,we present a blade-coating compatible methodology for fabricating highperformance 2D/3D PSCs utilizing a low-volatility t-amyl alcohol(t-AmOH)-dimethylformamide(DMF)mixed solvent system.Through systematic materials characterization and comprehensive device performance analysis,we demonstrate that this approach facilitates uniform spatial distribution of butylammonium iodide(BAI)organic spacers,thereby promoting the formation of a high-quality 2D/3D perovskite architecture characterized by enhanced crystallinity and substantially reduced defect density.The optimized device achieves a champion power conversion efficiency of 22.25%while demonstrating exceptional operational stability,retaining 83%of its initial performance after prolonged exposure under ambient conditions(45%relative humidity)for 1000 h.展开更多
In agricultural irrigation engineering,deep leakage is a key factor that significantly reduces the utilization efficiency of irrigation water.Underground installation of porous membranes,as a novel active regulation t...In agricultural irrigation engineering,deep leakage is a key factor that significantly reduces the utilization efficiency of irrigation water.Underground installation of porous membranes,as a novel active regulation technology,can effectively reduce deep leakage losses of water in the soil through its physical barrier effect.However,the current understanding of the infiltration patterns of underground porous membranes remains inadequate,limiting the promotion and application of this technology.Therefore,this study integrates a methodology that combines numerical simulations with experimental validations.Using a non-membrane treatment as a control(CK),this study investigated the soil water infiltration of underground porous membranes under various combinations of saturated hydraulic conductivity(K_(s)),porous membrane diameter(D),burial depth(H),and spacing(S).The results indicated that under the four types of aeolian sandy soil conditions,underground installation of porous membranes had a significant impact on soil infiltration characteristics,exhibiting an infiltration-reducing effect.Upon entering the steady infiltration stage,the minimum reduction in the infiltration rate for the various porous membrane treatments was 2.86 times that of the CK treatment.At a specific irrigation time(t),the steady infiltration rate(i_(f))and cumulative infiltration(I)of soil increased with increasing K_(s),D,H,and S.There was a strong power function relationship between i_(f)and the four factors(R^(2)=0.997),with a coefficient of 0.209,and exponents of 1.14,1.04,0.48,and 0.30,respectively.Furthermore,based on the Kostiakov infiltration model and comprehensively considering K_(s),D,H,S,and t,an estimation model for cumulative infiltration of underground porous membranes was developed.The reliability of the estimation model was assessed using experimental data,with the root mean square error approaching 0 and the Nash-Sutcliffe efficiency coefficient close to 1,indicating the good predictive performance of the model.The findings of this study can provide a scientific basis for the operation and management of underground porous membrane irrigation projects.展开更多
Stab-resistant textiles play a critical role in personal protection,necessitating a deeper understanding of how structural and layering factors influence their performance.The current study experimentally examines the...Stab-resistant textiles play a critical role in personal protection,necessitating a deeper understanding of how structural and layering factors influence their performance.The current study experimentally examines the effects of textile structure,layering,and ply orientation on the stab resistance of multi-layer textiles.Three 3D warp interlock(3DWI)structures({f1},{f2},{f3})and a 2D woven fabric({f4}),all made of high-performance p-aramid yarns,were engineered and manufactured.Multi-layer specimens were prepared and subjected to drop-weight stabbing tests following HOSBD standards.Stabbing performance metrics,including Depth of Trauma(DoT),Depth of Penetration(DoP),and trauma deformation(Ymax,Xmax),were investigated and analyzed.Statistical analyses(Two-and One-Way ANOVA)indicated that fabric type and layer number significantly impacted DoP(P<0.05),while ply orientation significantly affected DoP(P<0.05)but not DoT(P>0.05).Further detailed analysis revealed that 2D woven fabrics exhibited greater trauma deformation than 3D WIF structures.Increasing the number of layers reduced both DoP and DoT across all fabric structures,with f3 demonstrating the best performance in multi-layer configurations.Aligned ply orientations also enhanced stab resistance,underscoring the importance of alignment in dissipating impact energy.展开更多
Despite numerous research investigations to understand the influences of various structural parameters,to the authors'knowledge,no research has been the effect of different angles of incidence on stab response and...Despite numerous research investigations to understand the influences of various structural parameters,to the authors'knowledge,no research has been the effect of different angles of incidence on stab response and performance of different types of protective textiles.Three distinct structures of 3D woven textiles and 2D plain weave fabric made with similar high-performance fiber and areal density were designed and manufactured to be tested.Two samples,one composed of a single and the other of 4-panel layers,from each fabric type structure,were prepared,and tested against stabbing at[0○],[22.5○],and[45○]angle of incidence.A new stabbing experimental setup that entertained testing of the specimens at various angles of incidence was engineered and utilized.The stabbing bench is also equipped with magnetic sensors and a UK Home Office Scientific Development Branch(HOSDB)/P1/B sharpness engineered knives to measure the impact velocity and exerted impact energy respectively.A silicon compound was utilized to imprint the Back Face Signature(BFS)on the backing material after every specimen test.Each silicon print was then scanned,digitized,and precisely measured to evaluate the stab response and performance of the specimen based on different performance variables,including Depth of Trauma(DOT),Depth of Penetration(DOP),and Length of Penetration(LOP).Besides,the post-impact surface failure modes of the fabrics were also measured using Image software and analyzed at the microscale level.The results show stab angle of incidence greatly influences the stab response and performance of protective textiles.The outcome of the study could provide not only valuable insights into understanding the stab response and capabilities of protective textiles under different angle of incidence,but also provide valuable information for protective textile manufacturer,armor developer and stab testing and standardizing organizations to consider the angle of incidence while developing,testing,optimizing,and using protective textiles in various applications.展开更多
基金thank the Shenzhen-Hong Kong-Macao Science and Technology Plan Project(Category C,Grant No.ZGCP)Research Grants Council of Hong Kong(Grant No.15302121)+4 种基金National Natural Science Foundation of China(21975214)National Key R&D Program of China(Grant No.2018YFC2000900)Seed Fund of Research Institute of Intelligent Wearable Systems(Grant No.CD45)Start-up Fund of The Hong Kong Polytechnic University(Grant No.BE1H)Departmental General Research Fund of The Hong Kong Polytechnic University(Grant No.UAME),and The Hong Kong Ph.D.Fellowship Scheme.
文摘Despite the impressive power conversion efficiency(PCE)beyond 25.5%,perovskite solar cells,especially the Sn-based variants,are poorly stable under normal operating conditions compared with the market-dominant silicon solar cells that can last for over 25 years.2D3D hybrid perovskite materials are one of the best options to overcome the instability chal-lenge without compromising efficiency.Indeed,a record performance of 1 year was reported in Pb-based 2D3D planar per-ovskite devices.However,the reaction between 2 and 3D perovskite molecules requires high temperatures(-300°C)and increased reaction time(-24 h)to achieve high-quality 2D3D hybrid perovskites.Herein,we base on the ability of chlorine to displace iodine from its ionic compounds in solutions to utilize chloride ions as catalysts for speeding up the reaction between iodine-based 2D and 3D perovskite molecules.The approach reduces the reaction time to-20 min and the reaction temperature to-100°C with the formation of high-quality 2D3D hybrid perovskites,free from pure 2D traces.Integrating the synthesized 2D3D hybrid perovskite material with 50%chlorine doping in a fiber-shaped solar cell architecture yielded the highest reported PCE of 11.96%in Sn-based fiber-shaped perovskite solar cells.The unencapsulated and encapsulated fiber-shaped solar cells could maintain 75%and 95.5%of their original PCE,respectively,after 3 months under room light and relative humidity of 35–40%,revealing the champion stability in Sn-based perovskite solar devices.The solar yarn also demonstrated constant energy output under changing light incident angles(0–180°).
基金supported by the National Key Research and Development Programs-Intergovernmental International Cooperation in Science and Technology Innovation Project(Grant No.2022YFE0118400)the Natural Science Foundation of Hunan Province(2023JJ50132)+1 种基金Shenzhen Science and Technology Innovation Committee(Grants Nos.JCYJ20220818100211025,and KCXST20221021111616039)Shenzhen Science and Technology Program(No.20231128110928003)。
文摘The introduction of two-dimensional(2D)perovskite layers on top of three-dimensional(3D)perovskite films enhances the performance and stability of perovskite solar cells(PSCs).However,the electronic effect of the spacer cation and the quality of the 2D capping layer are critical factors in achieving the required results.In this study,we compared two fluorinated salts:4-(trifluoromethyl)benzamidine hydrochloride(4TF-BA·HCl)and 4-fluorobenzamidine hydrochloride(4F-BA·HCl)to engineer the 3D/2D perovskite films.Surprisingly,4F-BA formed a high-performance 3D/2D heterojunction,while4TF-BA produced an amorphous layer on the perovskite films.Our findings indicate that the balanced intramolecular charge polarization,which leads to effective hydrogen bonding,is more favorable in 4F-BA than in 4TF-BA,promoting the formation of a crystalline 2D perovskite.Nevertheless,4TF-BA managed to improve efficiency to 24%,surpassing the control device,primarily due to the natural passivation capabilities of benzamidine.Interestingly,the devices based on 4F-BA demonstrated an efficiency exceeding 25%with greater longevity under various storage conditions compared to 4TF-BA-based and the control devices.
基金supported by the National Natural Science Foundation of China(No.21773089)the Henan Center for Outstanding Overseas Scientist(No.GZS2024004).
文摘Herein,a new type of two-dimensional(2D)/2D Ti_(3)C_(2)/TiO_(2) heterojunction was developed for efficient photocatalytic nitrogen reduction reaction(NRR),in which TiO_(2) nanosheets(TiO_(2) Ns)were designed as the main catalyst,while Ti_(3)C_(2) MXene served as the co-catalyst.Experimental and theoretical results revealed that Ti_(3)C_(2) MXene introduced electron-rich unsaturated Ti sites,serving as highly active sites for both the adsorption and activation of N_(2) on the Ti_(3)C_(2)/TiO_(2) heterojunction.Furthermore,the 2D/2D Ti_(3)C_(2)/TiO_(2) heterostructure greatly promoted the directional separation and transfer of charge carriers,facilitated by the internal electric field.This structural feature enabled the spatial separation of the N_(2) reduction and H2 O oxidation half-reactions on the distinct surfaces of Ti_(3)C_(2)(001)and TiO_(2)(001),con-sequently reducing the reaction energy barrier for each respective process.The synergistic effects arising from the interface and surface interactions within the heterojunction conspicuously improved the photo-catalytic NRR activity.As a result,the optimized Ti_(3)C_(2)/TiO_(2) heterojunction exhibited a high NH_(3) produc-tion rate of 24.4μmol g−1 h−1 in the absence of sacrificial agents,representing a remarkable 12.8-fold increase compared to individual TiO_(2) Ns.This work provides new insights into rational design of high-performance heterogeneous photocatalysts and offers a deeper understanding of the mechanism under-lying surface active sites in the photocatalytic NRR process.
基金projects of China Railway Beijing Group Company Limited.(No.2016CG23)for funding this research。
文摘The geological disasters such as collapse,mud bursting and water gushing often occur during tunnel construction.Thus,it is of great significance to detect the hidden geological disasters ahead of the tunnel face.The audio magnetotelluric(AMT)was applied for the advanced detectionstudy during the boring process of the Tianheshan tunnel in the Taihang Mountains.Three AMT profiles were deployed above the tunnel,and the data obtained in the field were analysed in terms of electrical principal axes.From shallow to deep,the direction of the geoelectric strike angle changes,generally between 30°and 60°NE,which is consistent with similar to the direction of the Taihangshan Uplift,and the data show some 3D characteristics.Two-dimensional(2D)and three-dimensional(3D)inversion methods were adopted to jointly study the subsurface structural information,and the resistivity model was geophysically and geologically interpreted.Two sets of low resistance anomalies were found,and it was hypothesised that the near-erect low-resistivity anomalies in the east might be a fragmentation zone,while the low resistance anomalies in the west,which are inclined to the westward,might be a tectonic structure or fragmentation zone related to the regional major fault,and the results of the tunnelling confirmed the reliability of the inversion interpretation.The 3D inversion can fully reflect the development scale and morphological changes of the fracture zone,and the inversion model is more reliable.Finally,it is concluded that the audio magnetotelluric method,which adopts advanced acquisition,processing and inversion interpretation techniques,is an effective means of over-detection of tunnels.
基金financial support provided by the Sichuan Science and Technology Program(No.2022NSFSC0226)Sichuan Science and Technology Program(No.2023ZYD0163)+6 种基金the Production-Education Integration Demonstration Project of Sichuan Provincethe Photovoltaic Industry Production-Education Integration Comprehensive Demonstration Base of Sichuan Province(Sichuan Financial Education[2022]No.106)China Tianfu Yongxing Laboratory Science and Technology Key Project(2023KJGG15)National Key Research and Development Program of China(2022YFB3803300)Beijing Natural Science Foundation(IS23037)the Department for Energy Security and Net Zero(project ID:NEXTCCUS)the ACT program(Accelerating CCS Technologies,Horizon2020 project NO.691712)。
文摘The 2D/3D heterojunction perovskites have garnered increasing attention due to their exceptional moisture and thermal stability.However,few works have paid attention to the influence of the subsequent change process of 2D/3D heterojunction PSC on the stability of PSCs.Moreover,the evolution of the interface and carrier dynamic behavior of the 2D/3D perovskite films with long-term operation has not been systematically developed befo re.In this work,the effects of 2D/3 D heterojunction evolution on the interface of perovskite films and different carrier dynamics during 2D/3D evolution are systematically analyzed for the first time.The decomposition of 2D/3D heterojunction in the perovskite film will have a certain impact on the surface and carrier dynamics behavior of perovskite.During the evolution of 2D/3D heterojunction,PbI_(2)crystals will appear,which will improve the interfacial energy level matching between the electron transport layer and perovskite film.With a long evolution time,some holes will appear on the surface of perovskite film.The open circuit voltage(V_(OC))of PSCs increased from 1.14 to1.18 V and the PCE increased to 23.21%after 300 h storage in the nitrogen atmosphere,and maintained 89%initial performance for with 3000 h stability test in N_(2)box.This discovery has a significant role in promoting the development of inverted heterojunction PSCs and constructing the revolution mechanism of charge carrier dynamic.
基金supported by ational Natural Science Foundation of China(Nos.62405293,62301509,62304209)Key Research and Development Program of Shanxi Province(No.202302030201001)Fundamental Research Program of Shanxi Province(Nos.202303021212191,202203021222079,20210302123203,202103021223185).
文摘Perovskite solar cells(PSCs)incorporating 2D/3D heterostructures have exhibited remarkable improvements in both power conversion efficiency and operational stability.Nevertheless,the prevalent spin-coating fabrication technique presents formidable challenges for scalable manufacturing processes.Herein,we present a blade-coating compatible methodology for fabricating highperformance 2D/3D PSCs utilizing a low-volatility t-amyl alcohol(t-AmOH)-dimethylformamide(DMF)mixed solvent system.Through systematic materials characterization and comprehensive device performance analysis,we demonstrate that this approach facilitates uniform spatial distribution of butylammonium iodide(BAI)organic spacers,thereby promoting the formation of a high-quality 2D/3D perovskite architecture characterized by enhanced crystallinity and substantially reduced defect density.The optimized device achieves a champion power conversion efficiency of 22.25%while demonstrating exceptional operational stability,retaining 83%of its initial performance after prolonged exposure under ambient conditions(45%relative humidity)for 1000 h.
基金the National Natural Science Foundation of China(Grant No.51969027)Corps Financial Science and Technology Plan Projects of Xinjiang Province,China(Grant No.2021DB012,2023AB059)Ministry of Science and Technology of the People’s Republic of China-Third Comprehensive Scientific Expedition to Xinjiang(Grant No.2021xjkk0804).
文摘In agricultural irrigation engineering,deep leakage is a key factor that significantly reduces the utilization efficiency of irrigation water.Underground installation of porous membranes,as a novel active regulation technology,can effectively reduce deep leakage losses of water in the soil through its physical barrier effect.However,the current understanding of the infiltration patterns of underground porous membranes remains inadequate,limiting the promotion and application of this technology.Therefore,this study integrates a methodology that combines numerical simulations with experimental validations.Using a non-membrane treatment as a control(CK),this study investigated the soil water infiltration of underground porous membranes under various combinations of saturated hydraulic conductivity(K_(s)),porous membrane diameter(D),burial depth(H),and spacing(S).The results indicated that under the four types of aeolian sandy soil conditions,underground installation of porous membranes had a significant impact on soil infiltration characteristics,exhibiting an infiltration-reducing effect.Upon entering the steady infiltration stage,the minimum reduction in the infiltration rate for the various porous membrane treatments was 2.86 times that of the CK treatment.At a specific irrigation time(t),the steady infiltration rate(i_(f))and cumulative infiltration(I)of soil increased with increasing K_(s),D,H,and S.There was a strong power function relationship between i_(f)and the four factors(R^(2)=0.997),with a coefficient of 0.209,and exponents of 1.14,1.04,0.48,and 0.30,respectively.Furthermore,based on the Kostiakov infiltration model and comprehensively considering K_(s),D,H,S,and t,an estimation model for cumulative infiltration of underground porous membranes was developed.The reliability of the estimation model was assessed using experimental data,with the root mean square error approaching 0 and the Nash-Sutcliffe efficiency coefficient close to 1,indicating the good predictive performance of the model.The findings of this study can provide a scientific basis for the operation and management of underground porous membrane irrigation projects.
文摘Stab-resistant textiles play a critical role in personal protection,necessitating a deeper understanding of how structural and layering factors influence their performance.The current study experimentally examines the effects of textile structure,layering,and ply orientation on the stab resistance of multi-layer textiles.Three 3D warp interlock(3DWI)structures({f1},{f2},{f3})and a 2D woven fabric({f4}),all made of high-performance p-aramid yarns,were engineered and manufactured.Multi-layer specimens were prepared and subjected to drop-weight stabbing tests following HOSBD standards.Stabbing performance metrics,including Depth of Trauma(DoT),Depth of Penetration(DoP),and trauma deformation(Ymax,Xmax),were investigated and analyzed.Statistical analyses(Two-and One-Way ANOVA)indicated that fabric type and layer number significantly impacted DoP(P<0.05),while ply orientation significantly affected DoP(P<0.05)but not DoT(P>0.05).Further detailed analysis revealed that 2D woven fabrics exhibited greater trauma deformation than 3D WIF structures.Increasing the number of layers reduced both DoP and DoT across all fabric structures,with f3 demonstrating the best performance in multi-layer configurations.Aligned ply orientations also enhanced stab resistance,underscoring the importance of alignment in dissipating impact energy.
文摘Despite numerous research investigations to understand the influences of various structural parameters,to the authors'knowledge,no research has been the effect of different angles of incidence on stab response and performance of different types of protective textiles.Three distinct structures of 3D woven textiles and 2D plain weave fabric made with similar high-performance fiber and areal density were designed and manufactured to be tested.Two samples,one composed of a single and the other of 4-panel layers,from each fabric type structure,were prepared,and tested against stabbing at[0○],[22.5○],and[45○]angle of incidence.A new stabbing experimental setup that entertained testing of the specimens at various angles of incidence was engineered and utilized.The stabbing bench is also equipped with magnetic sensors and a UK Home Office Scientific Development Branch(HOSDB)/P1/B sharpness engineered knives to measure the impact velocity and exerted impact energy respectively.A silicon compound was utilized to imprint the Back Face Signature(BFS)on the backing material after every specimen test.Each silicon print was then scanned,digitized,and precisely measured to evaluate the stab response and performance of the specimen based on different performance variables,including Depth of Trauma(DOT),Depth of Penetration(DOP),and Length of Penetration(LOP).Besides,the post-impact surface failure modes of the fabrics were also measured using Image software and analyzed at the microscale level.The results show stab angle of incidence greatly influences the stab response and performance of protective textiles.The outcome of the study could provide not only valuable insights into understanding the stab response and capabilities of protective textiles under different angle of incidence,but also provide valuable information for protective textile manufacturer,armor developer and stab testing and standardizing organizations to consider the angle of incidence while developing,testing,optimizing,and using protective textiles in various applications.
