Electrocatalytic nitrate reduction reaction(NO3RR)represents a sustainable and environmentally benign route for ammonia(NH3)synthesis.However,NO3RR is still limited by the competition from hydrogen evolution reaction(...Electrocatalytic nitrate reduction reaction(NO3RR)represents a sustainable and environmentally benign route for ammonia(NH3)synthesis.However,NO3RR is still limited by the competition from hydrogen evolution reaction(HER)and the high energy barrier in the hydrogenation step of nitrogen-containing intermediates.Here,we report a selective etching strategy to construct Ru M nanoalloys(M=Fe,Co,Ni,Cu)uniformly dispersed on porous nitrogen-doped carbon substrates for efficient neutral NH3electrosynthesis.Density functional theory calculations confirm that the synergic effect between Ru and transition metal M modulates the electronic structure of the alloy,significantly lowering the energy barrier for the conversion of*NO_(2)to*HNO_(2).Experimentally,the optimized Ru Fe-NC catalyst achieves 100%Faraday efficiency with a high yield rate of 0.83 mg h^(-1)mg^(-1)catat a low potential of-0.1 V vs.RHE,outperforming most reported catalysts.In situ spectroscopic analyses further demonstrate that the Ru M-NC effectively promotes the hydrogenation of nitrogen intermediates while inhibiting the formation of hydrogen radicals,thereby reducing HER competition.The Ru FeNC assembled Zn-NO_(3)^(-)battery achieved a high open-circuit voltage and an outstanding power density and capacity,which drive selective NO_(3)^(-)conversion to NH3.This work provides a powerful synergistic design strategy for efficient NH3electrosynthesis and a general framework for the development of advanced multi-component catalysts for sustainable nitrogen conversion.展开更多
With the advantage of fast charge transfer,heterojunction engineering is identified as a viable method to reinforce the anodes'sodium storage performance.Also,vacancies can effectively strengthen the Na+adsorption...With the advantage of fast charge transfer,heterojunction engineering is identified as a viable method to reinforce the anodes'sodium storage performance.Also,vacancies can effectively strengthen the Na+adsorption ability and provide extra active sites for Na+adsorption.However,their synchronous engineering is rarely reported.Herein,a hybrid of Co_(0.85)Se/WSe_(2) heterostructure with Se vacancies and N-doped carbon polyhedron(CoWSe/NCP)has been fabricated for the first time via a hydrothermal and subsequent selenization strategy.Spherical aberration-corrected transmission electron microscopy confirms the phase interface of the Co_(0.85)Se/WSe_(2) heterostructure and the existence of Se vacancies.Density functional theory simulations reveal the accelerated charge transfer and enhanced Na+adsorption ability,which are contributed by the Co_(0.85)Se/WSe_(2) heterostructure and Se vacancies,respectively.As expected,the CoWSe/NCP anode in sodium-ion battery achieves outstanding rate capability(339.6 mAh g^(−1) at 20 A g^(−1)),outperforming almost all Co/W-based selenides.展开更多
Increasing attention has been paid to rechargeable aqueous batteries due to their high safety and low cost.However,they remain in their infancy because of the limited choice of available anode materials with high spec...Increasing attention has been paid to rechargeable aqueous batteries due to their high safety and low cost.However,they remain in their infancy because of the limited choice of available anode materials with high specific capacity and satisfying cycling performance.Bi metal with layered structure can act as an ideal anode material with high capacity;however,the energy storage mechanism has not well elucidated.Herein,we demonstrate that Bi metal enables affording ultra-high specific capacity(254.3 mAh g^-1),superior rate capability and a capacity retention of 88.8%after 1600 cycles.Different from the previously-reported redox reaction mechanisms of Bi electrode,efficient(de)alloying of K+is responsible for its excellent performance.An excellent aqueous Bi battery is fabricated by matching Bi anode with Co(OH)2 cathode in KOH(1 M)electrolyte.Its outstanding performance is quite adequate and competitive for electrochemical energy storage devices.展开更多
Inspired by a well-known architecture notion that load-bearing walls enable maintaining a highly-stable multiple-floored building,superior advantages are afforded via fabricating the NH_(4)+ions pre-intercalated Mo_(2...Inspired by a well-known architecture notion that load-bearing walls enable maintaining a highly-stable multiple-floored building,superior advantages are afforded via fabricating the NH_(4)+ions pre-intercalated Mo_(2)CT_(x) MXene(Mo_(2)CT_(x)-N)in a mixed solution of NH_(4)F and HCl via a simple one-step hydrothermal method.As a result of the synergistic effects of pillared structure,immobilizing-F groups and unlocking Mo-based redox,the Mo_(2)CT_(x)-N remarkably delivered a reversible capacity of 384.6 mAh ^(g-1) at 200 mA g^(-1) after 100 cycles.Our work lays a foundation for fully packaging its optimal performance via carding and architecting the chemistry of the MXene layers and between them.展开更多
Oxygen evolution reaction(OER)is a bottleneck half-reaction in many important energy conversion processes(e.g.,water splitting),and one of the key issues lies to develop high-efficiency,cost-effective OER electrocatal...Oxygen evolution reaction(OER)is a bottleneck half-reaction in many important energy conversion processes(e.g.,water splitting),and one of the key issues lies to develop high-efficiency,cost-effective OER electrocatalysts.Rather than those popular extrinsic modulations of any catalysts with gradually degraded performance,we aim at the utilization of the intermediates offered from the undergoing OER as long-standing electrocatalysts.Herein,by inverted design,we extracted the bimetallic borides(FeCoB_(2))-derived intermediates metal borates in the OER,unlocking their potential as a selffunctionalized highly active catalytic phase in-situ formed on the metal boride surface for continuing OER operation.Mechanistically,the surface metal atoms are oxidized to oxyhydroxides,and the surface metalloids(B)are further transformed to the corresponding oxoanions to form metal borates.Such OER self-produced electrocatalyst exhibits a small overpotential of 295 mV at 10 mA/cm2 and its high catalytic activity lasts even after 200 h.Compared with FeCoB_(2),the catalytic activity of this electrochemically activated FeCoB_(2) is~7 times higher.The in-situ formed metal borate is dominatingly responsible for the obtained high catalytic activity.Such unique OER-produced self-functionalization surfaces of metal borates afford to greatly reduce the energy barrier of the continuing OER,thereby accelerating the reaction process.展开更多
MXene quantum dots(MQDs)offer wide applications owing to the abundant surface chemistry,tunable energy-level structure,and unique properties.However,the application of MQDs in electrochemical energy conversion,includi...MXene quantum dots(MQDs)offer wide applications owing to the abundant surface chemistry,tunable energy-level structure,and unique properties.However,the application of MQDs in electrochemical energy conversion,including hydrogen evolution reaction(HER),remains to be realized,as it remains a challenge to precisely control the types of surface groups and tune the structure of energy levels in MQDs,owing to the high surface energy-induced strong agglomeration in post-processing.Consequently,the determination of the exact catalytically active sites and processes involved in such an electrocatalysis is challenging because of the complexity of the synthetic process and reaction conditions.Herein,we demonstrated the spontaneous evolution of the surface groups of the Ti_(2)CT_(x)MQDs(x:the content of O atom),i.e.,replacement of the-Cl functional groups by O-terminated ones during the cathode reaction.This process resulted in a low Gibbs free energy(0.26 eV)in HER.Our steady Ti_(2)CO_(x)/Cu_(2)O/Cu foam systems exhibited a low overpotential of 175 mV at 10 mA cm^(-2)in 1 M aq.KOH,and excellent operational stability over 165 h at a constant current density of-10 mA cm^(-2).展开更多
Objective: This study was designed to explore whether inhibition of the extracellular-regulated kinase (ERK) and phosphatidylinositol-3-kinase (PI3K) signaling pathways can inhibit the growth of xenografts of endometr...Objective: This study was designed to explore whether inhibition of the extracellular-regulated kinase (ERK) and phosphatidylinositol-3-kinase (PI3K) signaling pathways can inhibit the growth of xenografts of endometrial cancer cell lines with different estrogen receptors (ER) profiles in vivo and to provide preliminary laboratory basis for the probability of endometrial adenocarcinoma treatment with blockage of the two pathways, especially to endometrial cancer with low ER status. Methods: Human endometrial cancer Ishikawa bearing ER and HEC-1Awith low ER status cells were subcutaneously injected into BALB/c nude mice to establish endometrial cancer xenograft tumor models. The effects of PI3K/Akt inhibitor LY294002, MAPK/ERK1/2 inhibitor PD-98059 and their combinations on the growth of the xenograft tumors and apoptotic state of Ishikawa and HEC-1Acells were tested in vivo using the inhibitory rate, the terminal deoxynucleotidyl transferase-mediated nick-end labeling assay, H/E-stain. Western blot analysis was used to detect the alterations of activated ERK (P-ERK) and AKT (P-AKT) during this process. Results: LY294002, a PI3K/Akt pathway inhibitor, induced significant suppression in the growth of both Ishikawa and HEC-1Acell xenograft tumors, concomitant with increased apoptosis in xenografts as evidenced by TUNEL. A similar effect was also observed when the MAPK/ERK1/2 signaling pathway was inhibited by PD98059. Concurrent inhibition of the PI3K/Akt and MAPK/ERK1/2 pathways showed enhanced anti-tumor effects in vivo as indicated by increased apoptosis. At the same time, the levels of P-ERK and P-AKT in both xenograft tumors decreased, and their levels in combination group was the lowest. Conclusions: PD98059, LY294002 and their combinations showed remarkable inhibitory effects on xenograft tumors of endometrial carcinoma cell lines with different expression status of ER in vivo through blockage of PI3K/Akt and MAPK/ERK1/2 signaling pathways. This suggests that targeting these pathways may be an effective therapeutic strategy against endometrial carcinomas, especially for ER-negative cancers which show poor response to endocrinal therapy.展开更多
This paper presents a comprehensive exploration into the integration of Internet of Things(IoT),big data analysis,cloud computing,and Artificial Intelligence(AI),which has led to an unprecedented era of connectivity.W...This paper presents a comprehensive exploration into the integration of Internet of Things(IoT),big data analysis,cloud computing,and Artificial Intelligence(AI),which has led to an unprecedented era of connectivity.We delve into the emerging trend of machine learning on embedded devices,enabling tasks in resource-limited environ-ments.However,the widespread adoption of machine learning raises significant privacy concerns,necessitating the development of privacy-preserving techniques.One such technique,secure multi-party computation(MPC),allows collaborative computations without exposing private inputs.Despite its potential,complex protocols and communication interactions hinder performance,especially on resource-constrained devices.Efforts to enhance efficiency have been made,but scalability remains a challenge.Given the success of GPUs in deep learning,lever-aging embedded GPUs,such as those offered by NVIDIA,emerges as a promising solution.Therefore,we propose an Embedded GPU-based Secure Two-party Computation(EG-STC)framework for Artificial Intelligence(AI)systems.To the best of our knowledge,this work represents the first endeavor to fully implement machine learning model training based on secure two-party computing on the Embedded GPU platform.Our experimental results demonstrate the effectiveness of EG-STC.On an embedded GPU with a power draw of 5 W,our implementation achieved a secure two-party matrix multiplication throughput of 5881.5 kilo-operations per millisecond(kops/ms),with an energy efficiency ratio of 1176.3 kops/ms/W.Furthermore,leveraging our EG-STC framework,we achieved an overall time acceleration ratio of 5–6 times compared to solutions running on server-grade CPUs.Our solution also exhibited a reduced runtime,requiring only 60%to 70%of the runtime of previously best-known methods on the same platform.In summary,our research contributes to the advancement of secure and efficient machine learning implementations on resource-constrained embedded devices,paving the way for broader adoption of AI technologies in various applications.展开更多
Due to the characteristics of chaotic systems,different cryptosystems based on chaos have been proposed to satisfy the security of multimedia data.A plain image-related chaotic algorithm is proposed by Luo et al.with ...Due to the characteristics of chaotic systems,different cryptosystems based on chaos have been proposed to satisfy the security of multimedia data.A plain image-related chaotic algorithm is proposed by Luo et al.with high speed and efficiency.Security weaknesses of the cryptosystem are studied in this paper.It is found that the important secret key information is leaked because an important parameter can be obtained after an inverse operation in the last step of the cryptosystems without secret key.Meanwhile,the value zero is processed improperly in quantification algorithm.Based on the weaknesses,chosen plaintext attack on the cryptosystem is proposed,by which,an important parameter,equivalent to secret key,can be calculated with a specific chosen plain image.With the obtained parameter,the plain image of any ciphered image,encrypted by the cryptosystem,can be recovered.Then,an improvement is proposed to solve the problems after modifying the quantification algorithm.It is from the experiments that chosen plaintext attack is valid and improved algorithm possesses better performance.展开更多
The dynamic performance of high-speed trains is significantly influenced by sudden changes in aerodynamic loads(ADLs)when exiting a tunnel in a windy environment.Focusing on a double-track tunnel under construction in...The dynamic performance of high-speed trains is significantly influenced by sudden changes in aerodynamic loads(ADLs)when exiting a tunnel in a windy environment.Focusing on a double-track tunnel under construction in a mountain railway,we established an aerodynamic model involving a train exiting the tunnel,and verified it in the Fluent environment.Overset mesh technology was adopted to characterize the train’s movement.The flow field involving the train,tunnel,and crosswinds was simulated using the Reynolds-averaged turbulence model.Then,we built a comprehensive train-track coupled dynamic model considering the influences of ADLs,to investigate the vehicles’dynamic responses.The aerodynamics and dynamic behaviors of the train when affected by crosswinds with different velocities and directions are analyzed and discussed.The results show that the near-wall side crosswind leads to sharper variations in ADLs than the far-wall side crosswind.The leading vehicle suffers from more severe ADLs than other vehicles,which worsens the wheel-rail interaction and causes low-frequency vibration of the car body.When the crosswind velocity exceeds 20 m/s,significant wheel-rail impacts occur,and the running safety of the train worsens rapidly.展开更多
The interaction between the airflow and train influences the aerodynamic characteristics and dynamic performance of high-speed trains.This study focused on the fluid-solid coupling effect of airflow and HST,and propos...The interaction between the airflow and train influences the aerodynamic characteristics and dynamic performance of high-speed trains.This study focused on the fluid-solid coupling effect of airflow and HST,and proposed a co-simulation(CS)approach between computational fluid dynamics and multi-body dynamics.Firstly,the aerodynamic model was developed by employing overset mesh technology and the finite volume method,and the detailed train-track coupled dynamic model was established.Then the User Data Protocol was adopted to build data communication channels.Moreover,the proposed CS method was validated by comparison with a reported field test result.Finally,a case study of the HST exiting a tunnel subjected to crosswind was conducted to compare differences between CS and offline simulation(OS)methods.In terms of the presented case,the changing trends of aerodynamic forces and car-body displacements calculated by the two methods were similar.Differences mainly lie in aerodynamic moments and transient wheel-rail impacts.Maximum pitching and yawing moments on the head vehicle in the two methods differ by 21.1 kN∙m and 29.6 kN∙m,respectively.And wheel-rail impacts caused by sudden changes in aerodynamic loads are significantly severer in CS.Wheel-rail safety indices obtained by CS are slightly greater than those by OS.This research proposes a CS method for aerodynamic characteristics and dynamic performance of the HST in complex scenarios,which has superiority in computational efficiency and stability.展开更多
In x-ray dark-field imaging using dual phase grating interferometer,multi-contrast signals are extracted from a set of acquired phase-stepping data by using the least-squares fitting algorithm.The extracted mean inten...In x-ray dark-field imaging using dual phase grating interferometer,multi-contrast signals are extracted from a set of acquired phase-stepping data by using the least-squares fitting algorithm.The extracted mean intensity,amplitude and visibility signals may be intrinsically biased.However,it is still unclear how large these biases are and how the data acquisition parameters influence the biases in the extracted signals.This work set out to address these questions.Analytical expressions of the biases of the extracted signals were theoretically derived by using a second-order Taylor series expansion.Extensive numerical simulations were performed to validate the theoretical results.It is illustrated that while the estimated mean intensity signal is always unbiased,the estimated amplitude and visibility signals are both positively biased.While the biases of the estimated amplitude signals are proportional to the inverse of the total number of phase steps,the biases of the estimated visibility signals are inversely proportional to the product of the total number of phase steps and the mean number of photons counted per phase step.Meanwhile,it is demonstrated that the dependence of the biases on the mean visibility is quite different from that of Talbot-Lau interferometer due to the difference in the intensity model.We expect that these results can be useful for data acquisition optimizations and interpretation of x-ray dark-field images.展开更多
Optical coherence tomography angiography(OCTA)is a powerful tool for non-invasive,label-free,three-dimensional vi-sualization of blood vessels down to the capillary level in vivo.However,its widespread usage is hinder...Optical coherence tomography angiography(OCTA)is a powerful tool for non-invasive,label-free,three-dimensional vi-sualization of blood vessels down to the capillary level in vivo.However,its widespread usage is hindered by the trade-off between transverse sampling rate and signal-to-noise ratio(SNR).This trade-off results in either a limited field of view(FOV)to maintain sampling density or loss of capillary details to fulfil FOV requirement.It also restricts microvascular quantifications,including flow velocimetry,which typically demand higher transverse sampling rate and SNR compared with standard qualitative OCTA.We introduce spectrally extended line field OCTA(SELF-OCTA),a cost-effective imag-ing modality that improves transverse sampling rate and SNR through spectrally encoded parallel sampling and in-creased signal acquired over longer periods,respectively.In the human skin and retina in vivo,we demonstrate its ad-vantages in achieving significantly extended FOV without sacrificing microvascular resolution,high sensitivity to slower flow without compromising FOV,and flow velocity quantification with the highest dynamic range,emphasizing that these features can be achieved with readily available and standard OCTA hardware settings.SELF-OCTA has the potential to make wide-field,high-resolution,quantitative angiographic imaging accessible to a wider population,thereby facilitating the early detection and follow-up of vascular-related diseases.展开更多
The original online version of this article (Guo, R., Wang, X., Zhang, R., Shi, H<span>., Qiao, Y., Yun, W., Ge, X., Lin, Y. and Lei, J. (2015) Response of Subcutaneous Xenografts of Endometrial Cancer in Nude M...The original online version of this article (Guo, R., Wang, X., Zhang, R., Shi, H<span>., Qiao, Y., Yun, W., Ge, X., Lin, Y. and Lei, J. (2015) Response of Subcutaneous Xenografts of Endometrial Cancer in Nude Mice to Inhibitors of Phosp</span><span>hatidylinositol 3-Kinase/Akt and Mitogen-Activated Protein Kinase (M</span><span>APK) </span><span>Pathways: An Effective Therapeutic Strategy for Endometrial Cancer. Journal of Cancer Therapy, 6, 1083-1092. </span><span "=""><a href="https://doi.org/10.4236/jct.2015.612118" target="_blank"><span>https://doi.org/10.4236/jct.2015.612118</span></a></span><span>) was published in November 2015. The author</span><span>s</span><span> wish</span><span "=""> </span><span>to correct the following error</span><span>.展开更多
基金financially supported by National Natural Science Foundation of China(22466010)Guizhou Provincial Basic Research Program(Natural Science)ZK[2023]47 and key program ZD[2025]075+6 种基金Innovation and Entrepreneurship Project for overseas Talents in Guizhou Province[2022]02Specific Natural Science Foundation of Guizhou University(X202207)the national undergraduate innovation and entrepreneurship training program(gzugc2023006gzusc2024012)SRT project of Guizhou university(2023SRT0292023SRT024)supported by Shanghai Technical Service Center of Science and Engineering Computing,Shanghai University。
文摘Electrocatalytic nitrate reduction reaction(NO3RR)represents a sustainable and environmentally benign route for ammonia(NH3)synthesis.However,NO3RR is still limited by the competition from hydrogen evolution reaction(HER)and the high energy barrier in the hydrogenation step of nitrogen-containing intermediates.Here,we report a selective etching strategy to construct Ru M nanoalloys(M=Fe,Co,Ni,Cu)uniformly dispersed on porous nitrogen-doped carbon substrates for efficient neutral NH3electrosynthesis.Density functional theory calculations confirm that the synergic effect between Ru and transition metal M modulates the electronic structure of the alloy,significantly lowering the energy barrier for the conversion of*NO_(2)to*HNO_(2).Experimentally,the optimized Ru Fe-NC catalyst achieves 100%Faraday efficiency with a high yield rate of 0.83 mg h^(-1)mg^(-1)catat a low potential of-0.1 V vs.RHE,outperforming most reported catalysts.In situ spectroscopic analyses further demonstrate that the Ru M-NC effectively promotes the hydrogenation of nitrogen intermediates while inhibiting the formation of hydrogen radicals,thereby reducing HER competition.The Ru FeNC assembled Zn-NO_(3)^(-)battery achieved a high open-circuit voltage and an outstanding power density and capacity,which drive selective NO_(3)^(-)conversion to NH3.This work provides a powerful synergistic design strategy for efficient NH3electrosynthesis and a general framework for the development of advanced multi-component catalysts for sustainable nitrogen conversion.
基金support from the Natural Science Foundation of Jilin Province(Grant No.20200201073JC)the National Natural Science Foundation of China(Grant No.52130101)+1 种基金Interdisciplinary Integration and Innovation Project of JLU(Grant No.JLUXKJC2021ZY01)the Fundamental Research Funds for the Central Universities.
文摘With the advantage of fast charge transfer,heterojunction engineering is identified as a viable method to reinforce the anodes'sodium storage performance.Also,vacancies can effectively strengthen the Na+adsorption ability and provide extra active sites for Na+adsorption.However,their synchronous engineering is rarely reported.Herein,a hybrid of Co_(0.85)Se/WSe_(2) heterostructure with Se vacancies and N-doped carbon polyhedron(CoWSe/NCP)has been fabricated for the first time via a hydrothermal and subsequent selenization strategy.Spherical aberration-corrected transmission electron microscopy confirms the phase interface of the Co_(0.85)Se/WSe_(2) heterostructure and the existence of Se vacancies.Density functional theory simulations reveal the accelerated charge transfer and enhanced Na+adsorption ability,which are contributed by the Co_(0.85)Se/WSe_(2) heterostructure and Se vacancies,respectively.As expected,the CoWSe/NCP anode in sodium-ion battery achieves outstanding rate capability(339.6 mAh g^(−1) at 20 A g^(−1)),outperforming almost all Co/W-based selenides.
基金financial support provided by the National Natural Science Foundation of China(Grant Nos.51932003,51872115 and 51802110)2020 International Cooperation Project of the Department of Science and Technology of Jilin Province,Program for the Development of Science and Technology of Jilin Province(20190201309JC)+3 种基金Jilin Province/Jilin University Co-Construction Project Funds for New Materials(SXGJSF2017-3,Branch-2/440050316A36)the Open Project Program of Wuhan National Laboratory for Optoelectronics(2018WNLOKF022)Program for JLU Science and Technology Innovative Research Team(JLUSTIRT,2017TD-09)the Fundamental Research Funds for the Central Universities JLU,“Double-First Class”Discipline for Materials Science&Engineering。
文摘Increasing attention has been paid to rechargeable aqueous batteries due to their high safety and low cost.However,they remain in their infancy because of the limited choice of available anode materials with high specific capacity and satisfying cycling performance.Bi metal with layered structure can act as an ideal anode material with high capacity;however,the energy storage mechanism has not well elucidated.Herein,we demonstrate that Bi metal enables affording ultra-high specific capacity(254.3 mAh g^-1),superior rate capability and a capacity retention of 88.8%after 1600 cycles.Different from the previously-reported redox reaction mechanisms of Bi electrode,efficient(de)alloying of K+is responsible for its excellent performance.An excellent aqueous Bi battery is fabricated by matching Bi anode with Co(OH)2 cathode in KOH(1 M)electrolyte.Its outstanding performance is quite adequate and competitive for electrochemical energy storage devices.
基金Supported by the National Natural Science Foundation of China(51932003,51872115)2020 International Cooperation Project of the Department of Science and Technology of Jilin Province(20200801001GH)+1 种基金the Science and Technology Research Project of Education Department of Jilin Province(JJKH20210453KJ,JJKH20210449KJ)the Joint Research Fund of Key Laboratory of Functional Materials Physics and Chemistry(Jilin Normal University)Ministry of Education(202101)。
文摘Inspired by a well-known architecture notion that load-bearing walls enable maintaining a highly-stable multiple-floored building,superior advantages are afforded via fabricating the NH_(4)+ions pre-intercalated Mo_(2)CT_(x) MXene(Mo_(2)CT_(x)-N)in a mixed solution of NH_(4)F and HCl via a simple one-step hydrothermal method.As a result of the synergistic effects of pillared structure,immobilizing-F groups and unlocking Mo-based redox,the Mo_(2)CT_(x)-N remarkably delivered a reversible capacity of 384.6 mAh ^(g-1) at 200 mA g^(-1) after 100 cycles.Our work lays a foundation for fully packaging its optimal performance via carding and architecting the chemistry of the MXene layers and between them.
基金Financially supported by the National Natural Science Foundation of China(51872115,52101256,51932003)China Postdoctoral Science Foundation Project(2020M680043)+1 种基金Science and Technology Research Project of the Department of Education of Jilin Province(JJKH20211083KJ)2020 International Cooperation Project of the Department of Science and Technology of Jilin Province(20200801001GH)。
文摘Oxygen evolution reaction(OER)is a bottleneck half-reaction in many important energy conversion processes(e.g.,water splitting),and one of the key issues lies to develop high-efficiency,cost-effective OER electrocatalysts.Rather than those popular extrinsic modulations of any catalysts with gradually degraded performance,we aim at the utilization of the intermediates offered from the undergoing OER as long-standing electrocatalysts.Herein,by inverted design,we extracted the bimetallic borides(FeCoB_(2))-derived intermediates metal borates in the OER,unlocking their potential as a selffunctionalized highly active catalytic phase in-situ formed on the metal boride surface for continuing OER operation.Mechanistically,the surface metal atoms are oxidized to oxyhydroxides,and the surface metalloids(B)are further transformed to the corresponding oxoanions to form metal borates.Such OER self-produced electrocatalyst exhibits a small overpotential of 295 mV at 10 mA/cm2 and its high catalytic activity lasts even after 200 h.Compared with FeCoB_(2),the catalytic activity of this electrochemically activated FeCoB_(2) is~7 times higher.The in-situ formed metal borate is dominatingly responsible for the obtained high catalytic activity.Such unique OER-produced self-functionalization surfaces of metal borates afford to greatly reduce the energy barrier of the continuing OER,thereby accelerating the reaction process.
基金supported by the National Natural Science Foundation of China(51872115,52101256,and 51932003)China Postdoctoral Science Foundation Project(2020 M680043)+1 种基金Science and Technology Research Project of the Department of Education of Jilin Province(JJKH20211083KJ)2020 International Cooperation Project of the Department of Science and Technology of Jilin Province(20200801001GH).
文摘MXene quantum dots(MQDs)offer wide applications owing to the abundant surface chemistry,tunable energy-level structure,and unique properties.However,the application of MQDs in electrochemical energy conversion,including hydrogen evolution reaction(HER),remains to be realized,as it remains a challenge to precisely control the types of surface groups and tune the structure of energy levels in MQDs,owing to the high surface energy-induced strong agglomeration in post-processing.Consequently,the determination of the exact catalytically active sites and processes involved in such an electrocatalysis is challenging because of the complexity of the synthetic process and reaction conditions.Herein,we demonstrated the spontaneous evolution of the surface groups of the Ti_(2)CT_(x)MQDs(x:the content of O atom),i.e.,replacement of the-Cl functional groups by O-terminated ones during the cathode reaction.This process resulted in a low Gibbs free energy(0.26 eV)in HER.Our steady Ti_(2)CO_(x)/Cu_(2)O/Cu foam systems exhibited a low overpotential of 175 mV at 10 mA cm^(-2)in 1 M aq.KOH,and excellent operational stability over 165 h at a constant current density of-10 mA cm^(-2).
文摘Objective: This study was designed to explore whether inhibition of the extracellular-regulated kinase (ERK) and phosphatidylinositol-3-kinase (PI3K) signaling pathways can inhibit the growth of xenografts of endometrial cancer cell lines with different estrogen receptors (ER) profiles in vivo and to provide preliminary laboratory basis for the probability of endometrial adenocarcinoma treatment with blockage of the two pathways, especially to endometrial cancer with low ER status. Methods: Human endometrial cancer Ishikawa bearing ER and HEC-1Awith low ER status cells were subcutaneously injected into BALB/c nude mice to establish endometrial cancer xenograft tumor models. The effects of PI3K/Akt inhibitor LY294002, MAPK/ERK1/2 inhibitor PD-98059 and their combinations on the growth of the xenograft tumors and apoptotic state of Ishikawa and HEC-1Acells were tested in vivo using the inhibitory rate, the terminal deoxynucleotidyl transferase-mediated nick-end labeling assay, H/E-stain. Western blot analysis was used to detect the alterations of activated ERK (P-ERK) and AKT (P-AKT) during this process. Results: LY294002, a PI3K/Akt pathway inhibitor, induced significant suppression in the growth of both Ishikawa and HEC-1Acell xenograft tumors, concomitant with increased apoptosis in xenografts as evidenced by TUNEL. A similar effect was also observed when the MAPK/ERK1/2 signaling pathway was inhibited by PD98059. Concurrent inhibition of the PI3K/Akt and MAPK/ERK1/2 pathways showed enhanced anti-tumor effects in vivo as indicated by increased apoptosis. At the same time, the levels of P-ERK and P-AKT in both xenograft tumors decreased, and their levels in combination group was the lowest. Conclusions: PD98059, LY294002 and their combinations showed remarkable inhibitory effects on xenograft tumors of endometrial carcinoma cell lines with different expression status of ER in vivo through blockage of PI3K/Akt and MAPK/ERK1/2 signaling pathways. This suggests that targeting these pathways may be an effective therapeutic strategy against endometrial carcinomas, especially for ER-negative cancers which show poor response to endocrinal therapy.
基金supported in part by Major Science and Technology Demonstration Project of Jiangsu Provincial Key R&D Program under Grant No.BE2023025in part by the National Natural Science Foundation of China under Grant No.62302238+2 种基金in part by the Natural Science Foundation of Jiangsu Province under Grant No.BK20220388in part by the Natural Science Research Project of Colleges and Universities in Jiangsu Province under Grant No.22KJB520004in part by the China Postdoctoral Science Foundation under Grant No.2022M711689.
文摘This paper presents a comprehensive exploration into the integration of Internet of Things(IoT),big data analysis,cloud computing,and Artificial Intelligence(AI),which has led to an unprecedented era of connectivity.We delve into the emerging trend of machine learning on embedded devices,enabling tasks in resource-limited environ-ments.However,the widespread adoption of machine learning raises significant privacy concerns,necessitating the development of privacy-preserving techniques.One such technique,secure multi-party computation(MPC),allows collaborative computations without exposing private inputs.Despite its potential,complex protocols and communication interactions hinder performance,especially on resource-constrained devices.Efforts to enhance efficiency have been made,but scalability remains a challenge.Given the success of GPUs in deep learning,lever-aging embedded GPUs,such as those offered by NVIDIA,emerges as a promising solution.Therefore,we propose an Embedded GPU-based Secure Two-party Computation(EG-STC)framework for Artificial Intelligence(AI)systems.To the best of our knowledge,this work represents the first endeavor to fully implement machine learning model training based on secure two-party computing on the Embedded GPU platform.Our experimental results demonstrate the effectiveness of EG-STC.On an embedded GPU with a power draw of 5 W,our implementation achieved a secure two-party matrix multiplication throughput of 5881.5 kilo-operations per millisecond(kops/ms),with an energy efficiency ratio of 1176.3 kops/ms/W.Furthermore,leveraging our EG-STC framework,we achieved an overall time acceleration ratio of 5–6 times compared to solutions running on server-grade CPUs.Our solution also exhibited a reduced runtime,requiring only 60%to 70%of the runtime of previously best-known methods on the same platform.In summary,our research contributes to the advancement of secure and efficient machine learning implementations on resource-constrained embedded devices,paving the way for broader adoption of AI technologies in various applications.
基金this paper was partially supported by the National Natural Science Foundation of China(Grant No.61601517)basic and advanced technology research project of Henan Province,China(Grant No.2014302703).
文摘Due to the characteristics of chaotic systems,different cryptosystems based on chaos have been proposed to satisfy the security of multimedia data.A plain image-related chaotic algorithm is proposed by Luo et al.with high speed and efficiency.Security weaknesses of the cryptosystem are studied in this paper.It is found that the important secret key information is leaked because an important parameter can be obtained after an inverse operation in the last step of the cryptosystems without secret key.Meanwhile,the value zero is processed improperly in quantification algorithm.Based on the weaknesses,chosen plaintext attack on the cryptosystem is proposed,by which,an important parameter,equivalent to secret key,can be calculated with a specific chosen plain image.With the obtained parameter,the plain image of any ciphered image,encrypted by the cryptosystem,can be recovered.Then,an improvement is proposed to solve the problems after modifying the quantification algorithm.It is from the experiments that chosen plaintext attack is valid and improved algorithm possesses better performance.
基金National Natural Science Foundation of China(No.52388102)New Cornerstone Science Foundation through the Xplorer Prize.
文摘The dynamic performance of high-speed trains is significantly influenced by sudden changes in aerodynamic loads(ADLs)when exiting a tunnel in a windy environment.Focusing on a double-track tunnel under construction in a mountain railway,we established an aerodynamic model involving a train exiting the tunnel,and verified it in the Fluent environment.Overset mesh technology was adopted to characterize the train’s movement.The flow field involving the train,tunnel,and crosswinds was simulated using the Reynolds-averaged turbulence model.Then,we built a comprehensive train-track coupled dynamic model considering the influences of ADLs,to investigate the vehicles’dynamic responses.The aerodynamics and dynamic behaviors of the train when affected by crosswinds with different velocities and directions are analyzed and discussed.The results show that the near-wall side crosswind leads to sharper variations in ADLs than the far-wall side crosswind.The leading vehicle suffers from more severe ADLs than other vehicles,which worsens the wheel-rail interaction and causes low-frequency vibration of the car body.When the crosswind velocity exceeds 20 m/s,significant wheel-rail impacts occur,and the running safety of the train worsens rapidly.
基金Supported by the Sichuan Science and Technology Program(Grant No.2023ZDZX0008)the National Natural Science Foundation of China(Grant No.52388102)the New Cornerstone Science Foundation through the XPLORER PRIZE.
文摘The interaction between the airflow and train influences the aerodynamic characteristics and dynamic performance of high-speed trains.This study focused on the fluid-solid coupling effect of airflow and HST,and proposed a co-simulation(CS)approach between computational fluid dynamics and multi-body dynamics.Firstly,the aerodynamic model was developed by employing overset mesh technology and the finite volume method,and the detailed train-track coupled dynamic model was established.Then the User Data Protocol was adopted to build data communication channels.Moreover,the proposed CS method was validated by comparison with a reported field test result.Finally,a case study of the HST exiting a tunnel subjected to crosswind was conducted to compare differences between CS and offline simulation(OS)methods.In terms of the presented case,the changing trends of aerodynamic forces and car-body displacements calculated by the two methods were similar.Differences mainly lie in aerodynamic moments and transient wheel-rail impacts.Maximum pitching and yawing moments on the head vehicle in the two methods differ by 21.1 kN∙m and 29.6 kN∙m,respectively.And wheel-rail impacts caused by sudden changes in aerodynamic loads are significantly severer in CS.Wheel-rail safety indices obtained by CS are slightly greater than those by OS.This research proposes a CS method for aerodynamic characteristics and dynamic performance of the HST in complex scenarios,which has superiority in computational efficiency and stability.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.U1532113,11475170,11905041)Anhui Provincial Natural Science Foundation(Grant No.2208085MA18)Fundamental Research Funds for the Central Universities(Grant No.JZ2022HGTB0244)。
文摘In x-ray dark-field imaging using dual phase grating interferometer,multi-contrast signals are extracted from a set of acquired phase-stepping data by using the least-squares fitting algorithm.The extracted mean intensity,amplitude and visibility signals may be intrinsically biased.However,it is still unclear how large these biases are and how the data acquisition parameters influence the biases in the extracted signals.This work set out to address these questions.Analytical expressions of the biases of the extracted signals were theoretically derived by using a second-order Taylor series expansion.Extensive numerical simulations were performed to validate the theoretical results.It is illustrated that while the estimated mean intensity signal is always unbiased,the estimated amplitude and visibility signals are both positively biased.While the biases of the estimated amplitude signals are proportional to the inverse of the total number of phase steps,the biases of the estimated visibility signals are inversely proportional to the product of the total number of phase steps and the mean number of photons counted per phase step.Meanwhile,it is demonstrated that the dependence of the biases on the mean visibility is quite different from that of Talbot-Lau interferometer due to the difference in the intensity model.We expect that these results can be useful for data acquisition optimizations and interpretation of x-ray dark-field images.
基金support from the Ministry of Education Singapore under its Academic Research Funding Tier 2 grant(MOE-T2EP30120-0001)Academic Research Funding Tier 1 grant(RG35/22)+1 种基金Singapore National Medical Research Council CS-NIG grant(MOH-CNIG24jan-0004)Guangzhou National Laboratory grant(GZNL2025C03014).
文摘Optical coherence tomography angiography(OCTA)is a powerful tool for non-invasive,label-free,three-dimensional vi-sualization of blood vessels down to the capillary level in vivo.However,its widespread usage is hindered by the trade-off between transverse sampling rate and signal-to-noise ratio(SNR).This trade-off results in either a limited field of view(FOV)to maintain sampling density or loss of capillary details to fulfil FOV requirement.It also restricts microvascular quantifications,including flow velocimetry,which typically demand higher transverse sampling rate and SNR compared with standard qualitative OCTA.We introduce spectrally extended line field OCTA(SELF-OCTA),a cost-effective imag-ing modality that improves transverse sampling rate and SNR through spectrally encoded parallel sampling and in-creased signal acquired over longer periods,respectively.In the human skin and retina in vivo,we demonstrate its ad-vantages in achieving significantly extended FOV without sacrificing microvascular resolution,high sensitivity to slower flow without compromising FOV,and flow velocity quantification with the highest dynamic range,emphasizing that these features can be achieved with readily available and standard OCTA hardware settings.SELF-OCTA has the potential to make wide-field,high-resolution,quantitative angiographic imaging accessible to a wider population,thereby facilitating the early detection and follow-up of vascular-related diseases.
文摘The original online version of this article (Guo, R., Wang, X., Zhang, R., Shi, H<span>., Qiao, Y., Yun, W., Ge, X., Lin, Y. and Lei, J. (2015) Response of Subcutaneous Xenografts of Endometrial Cancer in Nude Mice to Inhibitors of Phosp</span><span>hatidylinositol 3-Kinase/Akt and Mitogen-Activated Protein Kinase (M</span><span>APK) </span><span>Pathways: An Effective Therapeutic Strategy for Endometrial Cancer. Journal of Cancer Therapy, 6, 1083-1092. </span><span "=""><a href="https://doi.org/10.4236/jct.2015.612118" target="_blank"><span>https://doi.org/10.4236/jct.2015.612118</span></a></span><span>) was published in November 2015. The author</span><span>s</span><span> wish</span><span "=""> </span><span>to correct the following error</span><span>.
