This study analyzed through-thickness distribution of residual stress in a 106 mm ultra-thick TC4 titanium alloy electron beam welded(EBW)joint after post weld heat treatment(PWHT)using X-ray diffraction(XRD)and deep-...This study analyzed through-thickness distribution of residual stress in a 106 mm ultra-thick TC4 titanium alloy electron beam welded(EBW)joint after post weld heat treatment(PWHT)using X-ray diffraction(XRD)and deep-hole drilling(DHD)methods,and investigated the microstructure and mechanical properties.During the PWHT at 600℃,a phase transformation(β→α)occurred in the EBW joint and affected the residual stress distribution and mechanical properties.The surface residual stress was mainly compressive stress,while the internal residual stress was mainly tensile stress in the welded joint.For the as-welded joint,the absolute value of surface residual stress was higher than the absolute value of internal residual stress.After PWHT,the residual stress in the treated joint was substantially reduced compared to the as-welded joint,particularly the surface stress,which relieved from−425 to−90 MPa.However,the residual stress relief effect had minimal positive impact on the internal region at 600℃.PWHT resulted in a shift of the joint fracture location from the fusion zone(FZ)to the base metal(BM),and therefore exerted no noticeable effect on the joint strength,but increased the joint elongation significantly.This study provides valuable insights into the regulation of residual stress distribution of ultra-thick titanium alloy plates.展开更多
Rechargeable aqueous Zn-MoO_(x)batteries are promising energy storage devices with high theoretical specific capacity and low cost.However,MoO_(3)cathodes suffer drastic capacity decay during the initial discharging/c...Rechargeable aqueous Zn-MoO_(x)batteries are promising energy storage devices with high theoretical specific capacity and low cost.However,MoO_(3)cathodes suffer drastic capacity decay during the initial discharging/charging process in conventional electrolytes,resulting in a short cycle life and challenging the development of Zn-MoO_(x)batteries.Here we comprehensively investigate the dissolution mechanism of MoO_(3)cathodes and innovatively introduce a polymer to inhibit the irreversible processes.Our findings reveal that this capacity decay originates from the irreversible Zn^(2+)/H^(+)co-intercalation/extraction process in aqueous electrolytes.Even worse,during Zn^(2+)intercalation,the formed Zn_(x)MoO_(3-x)intermediate phase with lower valence states(Mo^(5+)/Mo^(4+))experiences severe dissolution in aqueous environments.To address these challenges,we developed a first instance of coating a polyaniline(PANI)shell around the MoO_(3)nanorod effectively inhibiting these irreversible processes and protecting structural integrity during long-term cycling.Detailed structural analysis and theoretical calculations indicate that=N-groups in PANI@MoO_(3-x)simultaneously weaken H+adsorption and enhance Zn^(2+)adsorption,which endowed the PANI@MoO_(3-x)cathode with reversible Zn^(2+)/H^(+)intercalation/extraction.Consequently,the obtained PANI@MoO_(3-x)cathode delivers an excellent discharge capacity of 316.86 mA h g^(-1)at 0.1 A g^(-1)and prolonged cycling stability of 75.49%capacity retention after 1000 cycles at 5 A g^(-1).This work addresses the critical issues associated with MoO_(3)cathodes and significantly advances the understanding of competitive multi-ion energy storage mechanisms in aqueous Zn-MoO_(3)batteries.展开更多
As core components of precision-guided projectiles,projectile-borne components are highly susceptible to failure or even damage in complex high-overload environments,thereby significantly compromising launch reliabili...As core components of precision-guided projectiles,projectile-borne components are highly susceptible to failure or even damage in complex high-overload environments,thereby significantly compromising launch reliability and safety.However,accurately characterizing the mechanical behavior of propellants remains challenging due to the limitations in the current internal ballistic theory and the constraints of large-scale artillery firing experiments.This complicates the high-precision numerical modeling of projectile launch,and obstructs investigations into the failure mechanisms of projectile-borne components.Therefore,this paper identifies propellant parameters using the computational inverse method under uncertainty,further establishes high-precision numerical models of projectile launch,and explores the failure mechanisms of projectile-borne components in complex high-overload environments.First,a projectile launching experiment is meticulously designed and executed to obtain the breech pressure and muzzle velocity.Then,a general simulation model is built,and the powder burn model is used to simulate the ignition and combustion.Subsequently,the propellant parameters are effectively identified with the computational inverse method by the combination of the experiments and simulations.A high-precision numerical model of projectile launch is modified with the parameters validated by another experiment,and the high-overload characteristics during projectile launch are thoroughly analyzed based on this model.Finally,the high-overload characteristics of projectile-borne components are analyzed to elucidate the stress variation laws and to reveal the failure mechanisms influenced by time and spatial locations.This research provides an effective method for perfectly identifying propellant parameters and building high-precision numerical models of projectile launch.Additionally,it provides significant guidance for the anti-high overload design and analysis of projectile-borne components.展开更多
Flexible phase change materials(PCMs)have become increasingly critical to address the demand for thermal management in electronic technologies and energy conversion.However,their application remains challenging becaus...Flexible phase change materials(PCMs)have become increasingly critical to address the demand for thermal management in electronic technologies and energy conversion.However,their application remains challenging because of their rigidity,liquid leakage,and insufficient thermal conductivity.Herein,flexible glutamic acid@natural rubber/paraffin wax(PW)/carbon nanotubes-graphene nanoplatelets(GNR/PW/CGNP)phase change composites with high thermal conductivity,excellent shape stability,and recyclability were reported.Zn^(2+)-based dynamic crosslinking was constructed through the reaction of zinc acetate and carboxyl groups on glutamic acid@natural rubber(GNR),which was used as a flexible matrix to physically blend with paraffin wax/carbon nanotubes/graphene nanoplatelets(PW/CGNP)to achieve uniform dispersion of PW/CGNP,continuous thermal conductivity networks,and good encapsulation of PW.The GNR/PW/CGNP composites showed excellent mechanical strength,flexibility,and recycling ability,and effective encapsulation prevented the outflow of melted PW during the phase transition.Also,the phase change enthalpy could attain 111.1 J/g with a higher thermal conductivity of 1.055 W/m K,428%higher than that of pure PW owing to the formation of efficient thermal conductive pathways,which exhibited outstanding thermal management performance and superior temperature control behavior in electronic devices.The developed flexible composite PCMs may open new possibilities for next-generation flexible thermal management electronics.展开更多
Based on the generalized reduced R-matrix theory,the R-matrix analysis code(RAC program)was used to analyze the experimental data of all the nuclear reaction channels related to the 5 He system.The current calculation...Based on the generalized reduced R-matrix theory,the R-matrix analysis code(RAC program)was used to analyze the experimental data of all the nuclear reaction channels related to the 5 He system.The current calculations provide accurate and reliable evaluation data and are in good agreement with the experimental data.In this study,self-consistent evaluation data for each reaction were obtained using multi-channel and multi-energy fitting.In particular,the error propagation theory of generalized least squares was used to determine the error of the evaluation data and the covariance matrix of the integral cross section.This R-matrix analysis for the 5 He system has three features.First,for the first time,the error in the evaluation data of the T(d,n)^(4)He reaction cross section and the covariance matrix of the integral cross section are provided.Second,we used only one set of R-matrix parameters to depict the reaction cross section of each reaction channel of the 5 He system for the entire energy region in our work.Third,in this evaluation,we considered some of the latest measured experimental data,especially after 2000.The T(d,n)^(4)He reaction cross section at 0.1 MeV and below was carefully studied.The effect of different energy levels in T(d,n)^(4)He was analyzed,with the energy levels 3/2^(+)making a major contribution to the cross section,and the role of the S-wave and P-wave from 3/2~-determines the lean forward trend of the angular distributions at 0.01–0.1 MeV.展开更多
The synthesis of high-quality heteroepitaxial diamond films on iridium composite substrates is a critical step toward advancing diamond for electronic and optical applications.Microwave plasma chemical vapor depositio...The synthesis of high-quality heteroepitaxial diamond films on iridium composite substrates is a critical step toward advancing diamond for electronic and optical applications.Microwave plasma chemical vapor deposition,combined with in situ optical emission spectroscopy,enables precise control over growth modes through plasma parameter tuning.In this study,we examine how methane concentration,microwave power,and gas pressure influence plasma species and,consequently,the growth modes of heteroepitaxial diamond by optical emission spectroscopy and scanning electron microscope.At low nucleation densities,increased methane concentrations promote the transition from faceted polyhedral to ballas structures,driven by elevated C_(2) radical concentrations in the plasma.Conversely,at higher nucleation densities,gas pressure,and substrate temperature dominate growth mode determination,leading to diverse morphologies,such as planar,polycrystalline,octahedral,and step-flow growth.These findings elucidate the interplay among plasma species,growth parameters,and growth mode,offering critical insights for optimizing growth conditions and preparing heteroepitaxial diamond films in a specific growth mode.展开更多
A nonfused ring electron acceptor(NFREA),designated as TT-Ph-C6,has been synthesized with the aim of enhancing the power conversion efficiency(PCE)of organic solar cells(OSCs).By integrating asymmetric phenylalkylamin...A nonfused ring electron acceptor(NFREA),designated as TT-Ph-C6,has been synthesized with the aim of enhancing the power conversion efficiency(PCE)of organic solar cells(OSCs).By integrating asymmetric phenylalkylamino side groups,TT-Ph-C6 demonstrates excellent solubility and its crystal structure exhibits compact packing structures with a three-dimensional molecular stacking network.These structural attributes markedly promote exciton diffusion and charge carrier mobility,particularly advantageous for the fabrication of thick-film devices.TT-Ph-C6-based devices have attained a PCE of 18.01%at a film thickness of 100 nm,and even at a film thickness of 300 nm,the PCE remains at 14.64%,surpassing that of devices based on 2BTh-2F.These remarkable properties position TT-Ph-C6 as a highly promising NFREA material for boosting the efficiency of OSCs.展开更多
When a porous rock is subjected to overall compressive loading,either increasing pore pressure or decreasing confining pressure could result in rock failure.The stress path and the applied pressure change rate may aff...When a porous rock is subjected to overall compressive loading,either increasing pore pressure or decreasing confining pressure could result in rock failure.The stress path and the applied pressure change rate may affect the initiation and propagation of fractures within brittle materials.Understanding the physical mechanisms leading to failure is crucial for underground engineering applications and geo-energy exploration and storage.We conducted triaxial compression experiments on porous Bentheim sandstone samples at different stress paths and pressure change rates.First,at a constant confining pressure of 35 MPa and pore pressure of 5 MPa,intact cylindrical samples were axially loaded up to about 85%of the peak strength.Subsequently,the axial piston position was fixed,and then either the pore pressure was increased or the confining pressure was decreased at two different rates(0.5 MPa/min or 2 MPa/min),leading to final catastrophic failure.The mechanical results revealed that samples subjected to higher rates of decreasing effective confining pressure exhibited larger stress drop rates,higher slip rates,higher total breakdown work,higher rates of acoustic emissions(AEs)before failure,and higher post-failure AE decay rates.In contrast,the applied stress path did not significantly affect rock failure characteristics.Comparison of located AE events with post-mortem microstructures of deformed samples shows a good agreement.The AE source type determined from the P-wave first-motion polarity shows that shear failure dominated the fracture process when approaching failure.Gutenberg-Richter b-values revealed a significant decrease before failure in all tests.Our results indicate that,in contrast to the stress path,the rate of effective stress change strongly affects fracturing behavior and AE rate changes.展开更多
Berberine,a constituent of some traditional Chinese medicinal plants,has been reported to have cytotoxicity effects on different human cancer cell lines.There is no available information about the effects and mechanis...Berberine,a constituent of some traditional Chinese medicinal plants,has been reported to have cytotoxicity effects on different human cancer cell lines.There is no available information about the effects and mechanism of action of berberine on human colon cancer cell line HCT-8.In this paper,the cytotoxicity of berberine on HCT-8 cancer cells was investigated by MTT assay,fluorescence microscopy and flow cytometry analysis.Our data revealed that berberine could significantly inhibit the growth of HCT-8 cells in a dose-and time-dependent manner.Morphology of apoptotic cells was studied with acridine orange/ethidium bromide staining.The concentrations of lactate dehydrogenase and both acid and alkaline phos-phatases were significantly increased in cell supernatants after berberine treatment,suggesting cell death.Furthermore,flow cytometry analysis showed that berberine could arrest HCT-8 cells at S phase in a time-dependent manner.To further investigate the apoptotic molecular mechanism,reverse transcription-poly-merase chain reaction(RT-PCR)and western blotting methods were used.The up-regulated mRNA and/or protein expressions of Fas,FasL,TNF-α,caspase-3 and down-regulation of pro-caspase-3 suggest that the death receptor pathway may be involved in the apoptotic pathway induced by berberine.Decrease of Bcl-2 and increase of Bax in mRNA and/or protein expressions showed that the Bcl-2 family proteins were involved in berberine-induced apoptosis.We also found that berberine-induced apoptosis was associated with an up-regulated expressions of p53 and prohibitin(PHB),and decreased vimentin expression.These results suggest that berberine can suppress cell growth and reduce cell survival by arresting the cell-cycle and by inducing apoptosis of HCT-8 cells.展开更多
目的探讨多模式预康复策略对老年衰弱结直肠癌手术患者的功能状态及短期预后的影响。方法回顾性收集2021年1月—2023年6月接受手术治疗的老年衰弱结直肠癌患者的临床资料,所有患者均采用加速康复外科(enhanced recovery after surgery,E...目的探讨多模式预康复策略对老年衰弱结直肠癌手术患者的功能状态及短期预后的影响。方法回顾性收集2021年1月—2023年6月接受手术治疗的老年衰弱结直肠癌患者的临床资料,所有患者均采用加速康复外科(enhanced recovery after surgery,ERAS)路径管理,依据是否实行多模式预康复分为预康复组和对照组。采用1∶2倾向性评分匹配平衡组间基线差异所致的混杂偏倚,比较匹配后两组患者资料,卡钳值设为0.1。主要观察指标为术后4周6分钟步行距离(6-minute walk distance,6MWD);次要观察指标为衰弱指数(frail index,FI)、手术时间、术中出血量、术后并发症、术后住院时间、术后30 d再入院率/再手术率及术后90 d死亡率。结果本研究最终共纳入182例患者(上海交通大学医学院附属第九人民医院62例,临沂市人民医院61例,聊城市人民医院59例),预康复组31例,对照组151例。经1∶2匹配后成功匹配93例患者,预康复组31例,对照组62例。术后4周预康复组6MWD改善值大于对照组[(46.3±33.7)m vs(7.6±30.2)m,P=0.002],预康复组6MWD改善值>20 m的患者数占比多于对照组(55%vs 9.9%,P=0.033)。FI预康复组小于对照组(中位数2 vs 3,P=0.024)。两组间手术时间、并发症发生率、术后30 d再入院率/再手术率及术后90 d死亡率差异无统计学意义(P>0.05)。术后住院时间预康复组长于对照组[(14.0±4.3)d vs(11.3±4.2)d,P=0.007]。结论多模式预康复策略未增加围手术期风险,有助于改善老年衰弱结直肠癌患者术后功能状态,可能提高患者对手术应激的耐受性,从而使其更好地从ERAS中获益。展开更多
基金supported by the National Key Research and Development Program of China(No.2023YFC2810700)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(2021193)the Science and Technology Cooperation Project between Jilin Province and Chinese Academy of Sciences(No.2024SYHZ0032).
文摘This study analyzed through-thickness distribution of residual stress in a 106 mm ultra-thick TC4 titanium alloy electron beam welded(EBW)joint after post weld heat treatment(PWHT)using X-ray diffraction(XRD)and deep-hole drilling(DHD)methods,and investigated the microstructure and mechanical properties.During the PWHT at 600℃,a phase transformation(β→α)occurred in the EBW joint and affected the residual stress distribution and mechanical properties.The surface residual stress was mainly compressive stress,while the internal residual stress was mainly tensile stress in the welded joint.For the as-welded joint,the absolute value of surface residual stress was higher than the absolute value of internal residual stress.After PWHT,the residual stress in the treated joint was substantially reduced compared to the as-welded joint,particularly the surface stress,which relieved from−425 to−90 MPa.However,the residual stress relief effect had minimal positive impact on the internal region at 600℃.PWHT resulted in a shift of the joint fracture location from the fusion zone(FZ)to the base metal(BM),and therefore exerted no noticeable effect on the joint strength,but increased the joint elongation significantly.This study provides valuable insights into the regulation of residual stress distribution of ultra-thick titanium alloy plates.
基金supported by National Natural Science Foundation of China(22209064,52071171,and 52202248)the Fundamental Research Funds for Public Universities in Liaoning(LJKLJ202434)+6 种基金the Australian Research Council(ARC)through Future Fellowship(FT210100298)Discovery Project(DP220100603)Linkage Project(LP210200504,LP220100088,LP230200897)Industrial Transformation Research Hub(IH240100009)schemesthe Australian Government through the Cooperative Research Centres Projects(CRCPXIII000077)the Australian Renewable Energy Agency(ARENA)as part of ARENA’s Transformative Research Accelerating Commercialisation Program(TM021)European Commission’s Australia-Spain Network for Innovation and Research Excellence(AuSpire)。
文摘Rechargeable aqueous Zn-MoO_(x)batteries are promising energy storage devices with high theoretical specific capacity and low cost.However,MoO_(3)cathodes suffer drastic capacity decay during the initial discharging/charging process in conventional electrolytes,resulting in a short cycle life and challenging the development of Zn-MoO_(x)batteries.Here we comprehensively investigate the dissolution mechanism of MoO_(3)cathodes and innovatively introduce a polymer to inhibit the irreversible processes.Our findings reveal that this capacity decay originates from the irreversible Zn^(2+)/H^(+)co-intercalation/extraction process in aqueous electrolytes.Even worse,during Zn^(2+)intercalation,the formed Zn_(x)MoO_(3-x)intermediate phase with lower valence states(Mo^(5+)/Mo^(4+))experiences severe dissolution in aqueous environments.To address these challenges,we developed a first instance of coating a polyaniline(PANI)shell around the MoO_(3)nanorod effectively inhibiting these irreversible processes and protecting structural integrity during long-term cycling.Detailed structural analysis and theoretical calculations indicate that=N-groups in PANI@MoO_(3-x)simultaneously weaken H+adsorption and enhance Zn^(2+)adsorption,which endowed the PANI@MoO_(3-x)cathode with reversible Zn^(2+)/H^(+)intercalation/extraction.Consequently,the obtained PANI@MoO_(3-x)cathode delivers an excellent discharge capacity of 316.86 mA h g^(-1)at 0.1 A g^(-1)and prolonged cycling stability of 75.49%capacity retention after 1000 cycles at 5 A g^(-1).This work addresses the critical issues associated with MoO_(3)cathodes and significantly advances the understanding of competitive multi-ion energy storage mechanisms in aqueous Zn-MoO_(3)batteries.
基金Project supported by the National Natural Science Foundation of China (No. 12302435)。
文摘As core components of precision-guided projectiles,projectile-borne components are highly susceptible to failure or even damage in complex high-overload environments,thereby significantly compromising launch reliability and safety.However,accurately characterizing the mechanical behavior of propellants remains challenging due to the limitations in the current internal ballistic theory and the constraints of large-scale artillery firing experiments.This complicates the high-precision numerical modeling of projectile launch,and obstructs investigations into the failure mechanisms of projectile-borne components.Therefore,this paper identifies propellant parameters using the computational inverse method under uncertainty,further establishes high-precision numerical models of projectile launch,and explores the failure mechanisms of projectile-borne components in complex high-overload environments.First,a projectile launching experiment is meticulously designed and executed to obtain the breech pressure and muzzle velocity.Then,a general simulation model is built,and the powder burn model is used to simulate the ignition and combustion.Subsequently,the propellant parameters are effectively identified with the computational inverse method by the combination of the experiments and simulations.A high-precision numerical model of projectile launch is modified with the parameters validated by another experiment,and the high-overload characteristics during projectile launch are thoroughly analyzed based on this model.Finally,the high-overload characteristics of projectile-borne components are analyzed to elucidate the stress variation laws and to reveal the failure mechanisms influenced by time and spatial locations.This research provides an effective method for perfectly identifying propellant parameters and building high-precision numerical models of projectile launch.Additionally,it provides significant guidance for the anti-high overload design and analysis of projectile-borne components.
基金financially supported by the China Postdoctoral Science Foundation(No.2024M751205)。
文摘Flexible phase change materials(PCMs)have become increasingly critical to address the demand for thermal management in electronic technologies and energy conversion.However,their application remains challenging because of their rigidity,liquid leakage,and insufficient thermal conductivity.Herein,flexible glutamic acid@natural rubber/paraffin wax(PW)/carbon nanotubes-graphene nanoplatelets(GNR/PW/CGNP)phase change composites with high thermal conductivity,excellent shape stability,and recyclability were reported.Zn^(2+)-based dynamic crosslinking was constructed through the reaction of zinc acetate and carboxyl groups on glutamic acid@natural rubber(GNR),which was used as a flexible matrix to physically blend with paraffin wax/carbon nanotubes/graphene nanoplatelets(PW/CGNP)to achieve uniform dispersion of PW/CGNP,continuous thermal conductivity networks,and good encapsulation of PW.The GNR/PW/CGNP composites showed excellent mechanical strength,flexibility,and recycling ability,and effective encapsulation prevented the outflow of melted PW during the phase transition.Also,the phase change enthalpy could attain 111.1 J/g with a higher thermal conductivity of 1.055 W/m K,428%higher than that of pure PW owing to the formation of efficient thermal conductive pathways,which exhibited outstanding thermal management performance and superior temperature control behavior in electronic devices.The developed flexible composite PCMs may open new possibilities for next-generation flexible thermal management electronics.
基金supported by Science Challenge Project(No.TZ20180001)。
文摘Based on the generalized reduced R-matrix theory,the R-matrix analysis code(RAC program)was used to analyze the experimental data of all the nuclear reaction channels related to the 5 He system.The current calculations provide accurate and reliable evaluation data and are in good agreement with the experimental data.In this study,self-consistent evaluation data for each reaction were obtained using multi-channel and multi-energy fitting.In particular,the error propagation theory of generalized least squares was used to determine the error of the evaluation data and the covariance matrix of the integral cross section.This R-matrix analysis for the 5 He system has three features.First,for the first time,the error in the evaluation data of the T(d,n)^(4)He reaction cross section and the covariance matrix of the integral cross section are provided.Second,we used only one set of R-matrix parameters to depict the reaction cross section of each reaction channel of the 5 He system for the entire energy region in our work.Third,in this evaluation,we considered some of the latest measured experimental data,especially after 2000.The T(d,n)^(4)He reaction cross section at 0.1 MeV and below was carefully studied.The effect of different energy levels in T(d,n)^(4)He was analyzed,with the energy levels 3/2^(+)making a major contribution to the cross section,and the role of the S-wave and P-wave from 3/2~-determines the lean forward trend of the angular distributions at 0.01–0.1 MeV.
基金funded by the National Key Research and Development Program of China(Grant No.2022YFB3608602)the National Natural Science Foundation of China(Grant Nos.62404215 and 62574199)Instrument and Equipment Development Project of CAS(Grant No.PTYQ2024TD0003)。
文摘The synthesis of high-quality heteroepitaxial diamond films on iridium composite substrates is a critical step toward advancing diamond for electronic and optical applications.Microwave plasma chemical vapor deposition,combined with in situ optical emission spectroscopy,enables precise control over growth modes through plasma parameter tuning.In this study,we examine how methane concentration,microwave power,and gas pressure influence plasma species and,consequently,the growth modes of heteroepitaxial diamond by optical emission spectroscopy and scanning electron microscope.At low nucleation densities,increased methane concentrations promote the transition from faceted polyhedral to ballas structures,driven by elevated C_(2) radical concentrations in the plasma.Conversely,at higher nucleation densities,gas pressure,and substrate temperature dominate growth mode determination,leading to diverse morphologies,such as planar,polycrystalline,octahedral,and step-flow growth.These findings elucidate the interplay among plasma species,growth parameters,and growth mode,offering critical insights for optimizing growth conditions and preparing heteroepitaxial diamond films in a specific growth mode.
基金Financial support from the National Natural Science Foundation of China(22375024,21975031,21734009,51933001,22109080,and 52173174)the Natural Science Foundation of Shandong Province(No.ZR2022YQ45)+2 种基金the Taishan Scholars Program(Nos.tstp20221121 and tsqnz20221134)The Beijing Natural Science Foundation(No.2244073)supported by State Key Laboratory of Bio-Fibers and Eco-Textiles(Qingdao University)(RZ2200002821)is acknowledged.
文摘A nonfused ring electron acceptor(NFREA),designated as TT-Ph-C6,has been synthesized with the aim of enhancing the power conversion efficiency(PCE)of organic solar cells(OSCs).By integrating asymmetric phenylalkylamino side groups,TT-Ph-C6 demonstrates excellent solubility and its crystal structure exhibits compact packing structures with a three-dimensional molecular stacking network.These structural attributes markedly promote exciton diffusion and charge carrier mobility,particularly advantageous for the fabrication of thick-film devices.TT-Ph-C6-based devices have attained a PCE of 18.01%at a film thickness of 100 nm,and even at a film thickness of 300 nm,the PCE remains at 14.64%,surpassing that of devices based on 2BTh-2F.These remarkable properties position TT-Ph-C6 as a highly promising NFREA material for boosting the efficiency of OSCs.
文摘When a porous rock is subjected to overall compressive loading,either increasing pore pressure or decreasing confining pressure could result in rock failure.The stress path and the applied pressure change rate may affect the initiation and propagation of fractures within brittle materials.Understanding the physical mechanisms leading to failure is crucial for underground engineering applications and geo-energy exploration and storage.We conducted triaxial compression experiments on porous Bentheim sandstone samples at different stress paths and pressure change rates.First,at a constant confining pressure of 35 MPa and pore pressure of 5 MPa,intact cylindrical samples were axially loaded up to about 85%of the peak strength.Subsequently,the axial piston position was fixed,and then either the pore pressure was increased or the confining pressure was decreased at two different rates(0.5 MPa/min or 2 MPa/min),leading to final catastrophic failure.The mechanical results revealed that samples subjected to higher rates of decreasing effective confining pressure exhibited larger stress drop rates,higher slip rates,higher total breakdown work,higher rates of acoustic emissions(AEs)before failure,and higher post-failure AE decay rates.In contrast,the applied stress path did not significantly affect rock failure characteristics.Comparison of located AE events with post-mortem microstructures of deformed samples shows a good agreement.The AE source type determined from the P-wave first-motion polarity shows that shear failure dominated the fracture process when approaching failure.Gutenberg-Richter b-values revealed a significant decrease before failure in all tests.Our results indicate that,in contrast to the stress path,the rate of effective stress change strongly affects fracturing behavior and AE rate changes.
基金the Excellent Young Scientist funds(number 2006J23JH024)of the Science and Technology Foundation of Dalian,Chinathe First Special China Post-Doctor Foundation(number 200801397)the Academic Scholarship for Doc-toral Candidates of Ministry of Education.
文摘Berberine,a constituent of some traditional Chinese medicinal plants,has been reported to have cytotoxicity effects on different human cancer cell lines.There is no available information about the effects and mechanism of action of berberine on human colon cancer cell line HCT-8.In this paper,the cytotoxicity of berberine on HCT-8 cancer cells was investigated by MTT assay,fluorescence microscopy and flow cytometry analysis.Our data revealed that berberine could significantly inhibit the growth of HCT-8 cells in a dose-and time-dependent manner.Morphology of apoptotic cells was studied with acridine orange/ethidium bromide staining.The concentrations of lactate dehydrogenase and both acid and alkaline phos-phatases were significantly increased in cell supernatants after berberine treatment,suggesting cell death.Furthermore,flow cytometry analysis showed that berberine could arrest HCT-8 cells at S phase in a time-dependent manner.To further investigate the apoptotic molecular mechanism,reverse transcription-poly-merase chain reaction(RT-PCR)and western blotting methods were used.The up-regulated mRNA and/or protein expressions of Fas,FasL,TNF-α,caspase-3 and down-regulation of pro-caspase-3 suggest that the death receptor pathway may be involved in the apoptotic pathway induced by berberine.Decrease of Bcl-2 and increase of Bax in mRNA and/or protein expressions showed that the Bcl-2 family proteins were involved in berberine-induced apoptosis.We also found that berberine-induced apoptosis was associated with an up-regulated expressions of p53 and prohibitin(PHB),and decreased vimentin expression.These results suggest that berberine can suppress cell growth and reduce cell survival by arresting the cell-cycle and by inducing apoptosis of HCT-8 cells.
