Designing a step-scheme(S-scheme)heterojunction photocatalyst with vacancy engineering is a reliable approach to achieve highly efficient photocatalytic H_(2)production activity.Herein,a hollow ZnO/ZnS S-scheme hetero...Designing a step-scheme(S-scheme)heterojunction photocatalyst with vacancy engineering is a reliable approach to achieve highly efficient photocatalytic H_(2)production activity.Herein,a hollow ZnO/ZnS S-scheme heterojunction with O and Zn vacancies(VO,Zn-ZnO/ZnS)is rationally constructed via ion-exchange and calcination treatments.In such a photocatalytic system,the hollow structure combined with the introduction of dual vacancies endows the adequate light absorption.Moreover,the O and Zn vacancies serve as the trapping sites for photo-induced electrons and holes,respectively,which are beneficial for promoting the photo-induced carrier separation.Meanwhile,the S-scheme charge transfer mechanism can not only improve the separation and transfer efficiencies of photo-induced carrier but also retain the strong redox capacity.As expected,the optimized VO,Zn-ZnO/ZnS heterojunction exhibits a superior photocatalytic H_(2) production rate of 160.91 mmol g^(-1)h^(-1),approximately 643.6 times and 214.5 times with respect to that obtained on pure ZnO and ZnS,respectively.Simultaneously,the experimental results and density functional theory calculations disclose that the photo-induced carrier transfer pathway follows the S-scheme heterojunction mechanism and the introduction of O and Zn vacancies reduces the surface reaction barrier.This work provides an innovative strategy of vacancy engineering in S-scheme heterojunction for solar-to-fuel energy conversion.展开更多
This study addresses the issues existing in the current cultivation process of outstanding graduate students and explores the collaborative education mechanism among in-school mentors,enterprise mentors,and counselors...This study addresses the issues existing in the current cultivation process of outstanding graduate students and explores the collaborative education mechanism among in-school mentors,enterprise mentors,and counselors in the cultivation of outstanding engineers in the mechanical field based on the perspective of Sanquan education(i.e.,holistic,full-course,and all-round education).Through exploring this mechanism,we attempt to construct a more scientific and efficient education model to enhance students’comprehensive quality and practical skills,thereby meeting society’s demand for high-quality talents in the mechanical field.展开更多
This study aims to address the problems existing in the ideological and political education of postgraduate students,and combines the implementation of the mentor responsibility system to explore the role orientation,...This study aims to address the problems existing in the ideological and political education of postgraduate students,and combines the implementation of the mentor responsibility system to explore the role orientation,work content,and practical effects of mentors in the ideological and political education of postgraduate students.Through questionnaire surveys,interviews,and other research methods,the current situation of ideological and political education of postgraduate students under the mentor responsibility system is analyzed,and corresponding optimization strategies are proposed.展开更多
Abstract--In this paper, an adaptive neural network （NN） control approach is proposed for nonlinear pure-feedback sys- tems with time-varying full state constraints. The pure-feedback systems of this paper are assum...Abstract--In this paper, an adaptive neural network （NN） control approach is proposed for nonlinear pure-feedback sys- tems with time-varying full state constraints. The pure-feedback systems of this paper are assumed to possess nonlinear function uncertainties. By using the mean value theorem, pure-feedback systems can be transformed into strict feedback forms. For the newly generated systems, NNs are employed to approximate unknown items. Based on the adaptive control scheme and backstepping algorithm, an intelligent controller is designed. At the same time, time-varying Barrier Lyapunov functions （BLFs） with error variables are adopted to avoid violating full state constraints in every step of the backstepping design. All closed- loop signals are uniformly ultimately bounded and the output tracking error converges to the neighborhood of zero, which can be verified by using the Lyapunov stability theorem. Two simulation examples reveal the performance of the adaptive NN control approach. Index TermsmAdaptive control, neural networks （NNs）, non- linear pure-feedback systems, time-varying constraints.展开更多
This study examines the effects of digital financial inclusion on non-farm employment of rural labor and the mediating mechanism of innovation and entrepreneurship activity using China Family Panel Studies(CFPS)and th...This study examines the effects of digital financial inclusion on non-farm employment of rural labor and the mediating mechanism of innovation and entrepreneurship activity using China Family Panel Studies(CFPS)and the provincial index of digital financial inclusion.Through the empirical test of the Probit model and mediation effect model,we found that:firstly,digital financial inclusion can promote non-farm employment of rural labor,with the level of digitalization having the most significant impact;secondly,by encouraging innovation and entrepreneurial activity,digital financial inclusion can promote non-farm employment of rural labor;thirdly,the driving effect of digital financial inclusion on non-farm employment of rural labor is more pronounced among the unmarried,eastern region,and male labor.Therefore,we should improve the construction of rural digital infrastructure and accelerate the development of inclusive rural finance to promote more diversified non-farm employment options for“disadvantaged groups”;encourage and support innovation at the government level,and create a favorable atmosphere for innovation and entrepreneurship.Simultaneously,farmers’digital literacy and financial knowledge should be improved so that more can adopt and take advantage of digital financial inclusion.展开更多
Photocatalytic degradation and hydrogen production using solar energy through semiconductor photocatalysts are deemed to be a powerful approach for solving environmental and energy crisis.However,the biggest challenge...Photocatalytic degradation and hydrogen production using solar energy through semiconductor photocatalysts are deemed to be a powerful approach for solving environmental and energy crisis.However,the biggest challenge in photocatalysis is the efficient separation of photo-induced carriers.To this end,we report that the mesoporous TiO_(2)nanoparticles are anchored on highly conductive Ti_(3)C_(2)MXene co-catalyst by electrostatic self-assembly strategy.The constructed mesoporous TiO_(2)/Ti_(3)C_(2)composites display that the mesoporous TiO_(2)nanoparticles are uniformly distributed on the surface of layer structured Ti_(3)C_(2)nanosheets.More importantly,the as-obtained mesoporous TiO_(2)/Ti_(3)C_(2)composites reveal the significantly enhanced light absorption performance,photo-induced carriers separation and transfer ability,thus boosting the photocatalytic activity.The photocatalytic methyl orange degradation efficiency of mesoporous TiO_(2)/Ti_(3)C_(2)composite with an optimized Ti_(3)C_(2)content(3 wt%)can reach 99.6%within 40 min.The capture experiments of active species confirm that the·O_(2)-and·OH play major role in photocatalytic degradation process.Furthermore,the optimized mesoporous TiO_(2)/Ti_(3)C_(2)composite also shows an excellent photocatalytic H2 production rate of 218.85μmol g^(-1)h^(-1),resulting in a 5.6 times activity as compared with the pristine mesoporous TiO_(2)nanoparticles.This study demonstrates that the MXene family materials can be applied as highly efficient noble-metal-free co-catalysts in the field of photocatalysis.展开更多
High-performance flexible one-dimensional(1D)electrochemical energy storage devices are crucial for the applications of wearable electronics.Although much progress on various 1D energy storage devices has been made,ch...High-performance flexible one-dimensional(1D)electrochemical energy storage devices are crucial for the applications of wearable electronics.Although much progress on various 1D energy storage devices has been made,challenges involving fabrication cost,scalability,and efficiency remain.Herein,a highperformance flexible all-fiber zinc-ion battery(ZIB)is fabricated using a low-cost,scalable,and efficient continuous wet-spinning method.Viscous composite inks containing cellulose nanofibers/carbon nanotubes(CNFs/CNTs)binary composite network and either manganese dioxide nanowires(MnO_(2) NWs)or commercial Zn powders are utilized to spinning fiber cathodes and anodes,respectively.MnO_(2) NWs and Zn powders are uniformly dispersed in the interpenetrated CNFs/CNTs fibrous network,leading to homogenous composite inks with an ideal shear-thinning property.The obtained fiber electrodes demonstrate favorable uniformity and flexibility.Benefiting from the well-designed electrodes,the assembled flexible fiber-shaped ZIB delivers a high specific capacity of 281.5 m Ah g^(-1) at 0.25 A g^(-1) and displays excellent cycling stability over 400 cycles.Moreover,the wet-spun fiber-shaped ZIBs achieve ultrahigh gravimetric and volumetric energy densities of 47.3 Wh kg^(-1) and 131.3 m Wh cm^(-3),respectively,based on both cathode and anode and maintain favorable stability even after 4000 bending cycles.This work offers a new concept design of 1D flexible ZIBs that can be potentially incorporated into commercial textiles for wearable and portable electronics.展开更多
This paper concentrates on asymmetric barrier Lyapunov functions(ABLFs)based on finite-time adaptive neural network(NN)control methods for a class of nonlinear strict feedback systems with time-varying full state cons...This paper concentrates on asymmetric barrier Lyapunov functions(ABLFs)based on finite-time adaptive neural network(NN)control methods for a class of nonlinear strict feedback systems with time-varying full state constraints.During the process of backstepping recursion,the approximation properties of NNs are exploited to address the problem of unknown internal dynamics.The ABLFs are constructed to make sure that the time-varying asymmetrical full state constraints are always satisfied.According to the Lyapunov stability and finitetime stability theory,it is proven that all the signals in the closedloop systems are uniformly ultimately bounded(UUB)and the system output is driven to track the desired signal as quickly as possible near the origin.In the meantime,in the scope of finitetime,all states are guaranteed to stay in the pre-given range.Finally,a simulation example is proposed to verify the feasibility of the developed finite time control algorithm.展开更多
Indoor air quality has a direct impact on human health. Indoor air quality has aroused great concern. This experimental study compares the effects of different water humidification on the indoor particulate pollution ...Indoor air quality has a direct impact on human health. Indoor air quality has aroused great concern. This experimental study compares the effects of different water humidification on the indoor particulate pollution characteristics, and analyzes the mass concentration and the particulate number concentration distribution of different sizes of particulates with time under each condition of the purified water humidification, the tap water humidification and the cold boiled water humidification in the office. The results show that under the three kinds of wetting conditions, the concentration of the fine particulates is higher. More minerals are contained in the tap water and the cold boiled water, so the two kinds of humidification have more significant impact on indoor particulate matter. But the purified water humidification has nearly no significant effect on it. The calcium and magnesium ionic compounds are partly removed after the water boiled, so the cold boiled water humidification has less impact on the indoor particulate matter than the tap water humidification. The mass concentration and particulate number concentration of the particle may also be affected due to the frequency of ultrasonic vibration.展开更多
Fibrous nanofluidic materials are ideal building blocks for implantable electrode,biomimetic actuator,wearable electronics due to their favorable features of intrinsic flexibility and unidirectional ion transport.Howe...Fibrous nanofluidic materials are ideal building blocks for implantable electrode,biomimetic actuator,wearable electronics due to their favorable features of intrinsic flexibility and unidirectional ion transport.However,the large-scale preparation of fibrous nanofluidic materials with desirable mechanical strength and good environment adaptability for practical use remains challenging.Herein,by fully taking advantage of the attractive mechanical,structural,chemical features of boron nitride(BN)nanosheet and nanofibrillated cellulose(NFC),a scalable and cost-effective three-dimensional(3D)printed macrofiber featuring abundant vertically aligned nanofluidic channels is demonstrated to exhibit a good combination of high tensile strength of 100 MPa,thermal stability of up to 230℃,ionic conductivity of 1.8×10^(−4)S/cm at low salt concentrations(<10^(−3)M).In addition,the versatile surface chemistry of cellulose allows us to stabilize the macrofiber at the molecular level via a facile postcross-linking method,which eventually enables the stable operation of the modified macrofiber in various extreme environments such as strong acidic,strong alkaline,high temperature.We believe this work implies a promising guideline for designing and manufacturing fibrous nanodevices towards extreme environment operations.展开更多
Owing to their appealing three-dimensional structures and tunable photophysical properties, emissive metallacages have been widely applied in recognition and sensing, adsorption and separation, catalysis, etc. Recentl...Owing to their appealing three-dimensional structures and tunable photophysical properties, emissive metallacages have been widely applied in recognition and sensing, adsorption and separation, catalysis, etc. Recently, the application of emissive metallacages in biomedical fields has emerged as a hot research topic, because multiple biological functionalities can be facilely integrated into metallacage-based platforms to deliver different functions. In this review, the applications of emissive metallacages in bio-imaging, delivery and cancer theranostics are systematically summarized. The dilemmas and challenges of metallacage-based biomedical materials are also raised at the end of this review. We hope this review would provide some guidance for the construction of novel emissive metallacages with biological functions, and further advance the development of emissive metallacages as biomedical materials.展开更多
To develop a national reference panel for severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)antigen detection kit and establish a quality standard.The cultures of SARS-CoV-2 and other pathogens were collected...To develop a national reference panel for severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)antigen detection kit and establish a quality standard.The cultures of SARS-CoV-2 and other pathogens were collected to establish a national reference panel for SARS-CoV-2 antigen detection.The stability and homogeneity of the reference panel were evaluated.Based on World Health Organization(WHO)guidance and nucleic acid quantitative results,a quality standard reference panel was established.Currently,three generations of SARS-CoV-2 antigen national reference materials with batch numbers 370095–202001,370095–202202,and 370095–202203 have been successfully established.These national reference panels comprised 8 positive samples,20 negative samples,1 repetitive sample,and 1 lower detection limit sample.The stability and homogeneity of the reference panel meet the requirements.The quality standards are as follows:the positive and negative coincidence rates are 8/8 and 20/20,respectively.The 10 test results of the medium and low-concentration repetitive reference materials should be positive,and the color rendering should be uniform(or the coefficient of variance should not be higher than 20.0%).The lower detection limit should be at least 5×105 U/mL(equivalent to copies/mL),and higher concentrations above the lower detection limit must be positive.A national reference panel for the SARS-CoV-2 antigen detection kit has been established.As the standard of SARS-CoV-2 antigen reagents,the reference panel has played a crucial role in the pre-marketing quality evaluation and post-marketing quality supervision in China.展开更多
Immunity-and-matrix-regulatory cells(IMRCs)derived from human embryonic stem cells have unique abilities in modulating immunity and regulating the extracellular matrix,which could be mass-produced with stable biologic...Immunity-and-matrix-regulatory cells(IMRCs)derived from human embryonic stem cells have unique abilities in modulating immunity and regulating the extracellular matrix,which could be mass-produced with stable biological properties.Despite resemblance to mesenchymal stem cells(MSCs)in terms of self-renew and tri-lineage differentiation,the ability of IMRCs to repair the meniscus and the underlying mechanism remains undetermined.Here,we showed that IMRCs demonstrated stronger immunomodulatory and pro-regenerative potential than umbilical cord MSCs when stimulated by synovial fluid from patients with meniscus injury.Following injection into the knees of rabbits with meniscal injury,IMRCs enhanced endogenous fibrocartilage regeneration.In the dose-escalating phase I clinical trial(NCT03839238)with eighteen patients recruited,we found that intra-articular IMRCs injection in patients was safe over 12 months post-grafting.Furthermore,the effective results of magnetic resonance imaging(MRI)of meniscus repair and knee functional scores suggested that 5×107 cells are optimal for meniscus injury treatment.In summary,we present the first report of a phase I clinical trial using IMRCs to treat meniscus injury.Our results demonstrated that intra-articular injection of IMRCs is a safe and effective therapy by providing a permissive niche for cartilage regeneration.展开更多
Hollow ternary metal oxides have shown enormous potential in lithium-ion batteries(LIBs),which is ascribed to their complex chemical composition,abundant active defect sites,and the synergy effect be-tween metals.In t...Hollow ternary metal oxides have shown enormous potential in lithium-ion batteries(LIBs),which is ascribed to their complex chemical composition,abundant active defect sites,and the synergy effect be-tween metals.In this work,we synthesized Mo-doped NiCo_(2)O_(4) porous spheres with yolk-shell structure by using a simple self-templating method.Surprisingly,other than the yolk-shell structure we had ob-tained,the inner core of the yolk-shell was also porous,which could fully enhance the electrolyte infil-tration and promote the transmission of lithium ions(Li+)and electrons(e−).The diameter of the porous core in the yolk-shell sphere was about 530 nm,and the outer shell’s thickness was up to 110 nm.In addition,the unique pores in the core appeared in the diameter of about 85 nm.With this structure,the volume expansion of the anode could be well inhibited during charge/discharge.It exhibited prominent electrochemical performance with high reversible capacity(1338 mA h g^(−1) at 100 mA g^(−1)),satisfactory cycle life(1360 mA h g^(−1) after 200 cycles at 100 mA g^(−1)),and exceptional rate capability(820 mA h g^(−1) at 2000 mA g^(−1))as anode material in LIBs.展开更多
Peroxymonosulfate(PMS)activation in heterogeneous processes is a promising water treatment technology.Nevertheless,the high energy consumption and low efficiency during the reaction are ineluctable,due to electron cyc...Peroxymonosulfate(PMS)activation in heterogeneous processes is a promising water treatment technology.Nevertheless,the high energy consumption and low efficiency during the reaction are ineluctable,due to electron cycling rate limitation.Herein,a new strategy is proposed based on a quantum dots(QDs)/PMS system.Co-ZnS QDs are synthesized by a water phase coprecipitation method.The inequivalent lattice-doping of Co for Zn leads to the generation of surface sulfur vacancies(SVs),which modulates the surface of the catalyst to form an electronic nonequilibrium surface.Astonishingly,the plasticizer micropollutants can be completely degraded within only tens of seconds in the Co-Zn S QDs/PMS system due to this type of surface modulation.The interfacial reaction mechanism is revealed that pollutants tend to be adsorbed on the cobalt metal sites as the electron donors,where the internal electrons of pollutants are captured by the metal species and transferred to the surface SVs.Meanwhile,PMS adsorbed on the SVs is reduced to radicals by capturing electrons,achieving effective electron recovery.Dissolved oxygen(DO)molecules are also easily attracted to catalyst defects and are reduced to O_(2)^(·-),further promoting the degradation of pollutants.展开更多
文摘Designing a step-scheme(S-scheme)heterojunction photocatalyst with vacancy engineering is a reliable approach to achieve highly efficient photocatalytic H_(2)production activity.Herein,a hollow ZnO/ZnS S-scheme heterojunction with O and Zn vacancies(VO,Zn-ZnO/ZnS)is rationally constructed via ion-exchange and calcination treatments.In such a photocatalytic system,the hollow structure combined with the introduction of dual vacancies endows the adequate light absorption.Moreover,the O and Zn vacancies serve as the trapping sites for photo-induced electrons and holes,respectively,which are beneficial for promoting the photo-induced carrier separation.Meanwhile,the S-scheme charge transfer mechanism can not only improve the separation and transfer efficiencies of photo-induced carrier but also retain the strong redox capacity.As expected,the optimized VO,Zn-ZnO/ZnS heterojunction exhibits a superior photocatalytic H_(2) production rate of 160.91 mmol g^(-1)h^(-1),approximately 643.6 times and 214.5 times with respect to that obtained on pure ZnO and ZnS,respectively.Simultaneously,the experimental results and density functional theory calculations disclose that the photo-induced carrier transfer pathway follows the S-scheme heterojunction mechanism and the introduction of O and Zn vacancies reduces the surface reaction barrier.This work provides an innovative strategy of vacancy engineering in S-scheme heterojunction for solar-to-fuel energy conversion.
基金Chang’an University Graduate Student Ideological and Political Education Innovation Demonstration Project(300103740013)Education Science Research Project of China Association of Transportation Education(JT2022YB222)。
文摘This study addresses the issues existing in the current cultivation process of outstanding graduate students and explores the collaborative education mechanism among in-school mentors,enterprise mentors,and counselors in the cultivation of outstanding engineers in the mechanical field based on the perspective of Sanquan education(i.e.,holistic,full-course,and all-round education).Through exploring this mechanism,we attempt to construct a more scientific and efficient education model to enhance students’comprehensive quality and practical skills,thereby meeting society’s demand for high-quality talents in the mechanical field.
基金Chang’an University Graduate Student Ideological and Political Education Innovation Demonstration Pro-ject(No.300103740013)Education Science Research Project of China Association of Transportation Education(No.JT2022YB222)+1 种基金Research Project on Education and Teaching Reform at Chang’an Dublin International College of Transpor-tation at Chang’an University(No.CDIC-JG-200301)Construction Project for Continuous Improvement of National First-Class Courses on Interchangeability and Measurement Technology(No.300103230119)。
文摘This study aims to address the problems existing in the ideological and political education of postgraduate students,and combines the implementation of the mentor responsibility system to explore the role orientation,work content,and practical effects of mentors in the ideological and political education of postgraduate students.Through questionnaire surveys,interviews,and other research methods,the current situation of ideological and political education of postgraduate students under the mentor responsibility system is analyzed,and corresponding optimization strategies are proposed.
基金supported in part by the National Natural Science Foundation of China(61622303,61603164,61773188)the Program for Liaoning Innovative Research Team in University(LT2016006)+1 种基金the Fundamental Research Funds for the Universities of Liaoning Province(JZL201715402)the Program for Distinguished Professor of Liaoning Province
文摘Abstract--In this paper, an adaptive neural network （NN） control approach is proposed for nonlinear pure-feedback sys- tems with time-varying full state constraints. The pure-feedback systems of this paper are assumed to possess nonlinear function uncertainties. By using the mean value theorem, pure-feedback systems can be transformed into strict feedback forms. For the newly generated systems, NNs are employed to approximate unknown items. Based on the adaptive control scheme and backstepping algorithm, an intelligent controller is designed. At the same time, time-varying Barrier Lyapunov functions （BLFs） with error variables are adopted to avoid violating full state constraints in every step of the backstepping design. All closed- loop signals are uniformly ultimately bounded and the output tracking error converges to the neighborhood of zero, which can be verified by using the Lyapunov stability theorem. Two simulation examples reveal the performance of the adaptive NN control approach. Index TermsmAdaptive control, neural networks （NNs）, non- linear pure-feedback systems, time-varying constraints.
基金Ministry of Education Humanities and Social Science Foundation Youth Project“Micro-Quantification,Action Mechanism and Impact Research on Financialization of Entity Enterprises”[Grant number.19YJC790106]National Social Science Fund“Mechanism Analysis and Optimization Path Research of Digital Finance Supporting the Improvement of development efficiency of SMEs”[Grant number.21BJY047]+1 种基金Science and Technology Research Program of Chongqing Municipal Education Commission of China:“Research on the Mechanism and Path of Green Finance to Promote Poverty Alleviation in Poor areas in Western China”[Grant number.KJQN201900550]Science and Technology Research Program of Chongqing Municipal Education Commission of China:“Research on Financial Efficiency and High-quality Innovation Development from the Perspective of the Innovation Value Chain”[Grant number.KJQN202000540].
文摘This study examines the effects of digital financial inclusion on non-farm employment of rural labor and the mediating mechanism of innovation and entrepreneurship activity using China Family Panel Studies(CFPS)and the provincial index of digital financial inclusion.Through the empirical test of the Probit model and mediation effect model,we found that:firstly,digital financial inclusion can promote non-farm employment of rural labor,with the level of digitalization having the most significant impact;secondly,by encouraging innovation and entrepreneurial activity,digital financial inclusion can promote non-farm employment of rural labor;thirdly,the driving effect of digital financial inclusion on non-farm employment of rural labor is more pronounced among the unmarried,eastern region,and male labor.Therefore,we should improve the construction of rural digital infrastructure and accelerate the development of inclusive rural finance to promote more diversified non-farm employment options for“disadvantaged groups”;encourage and support innovation at the government level,and create a favorable atmosphere for innovation and entrepreneurship.Simultaneously,farmers’digital literacy and financial knowledge should be improved so that more can adopt and take advantage of digital financial inclusion.
文摘Photocatalytic degradation and hydrogen production using solar energy through semiconductor photocatalysts are deemed to be a powerful approach for solving environmental and energy crisis.However,the biggest challenge in photocatalysis is the efficient separation of photo-induced carriers.To this end,we report that the mesoporous TiO_(2)nanoparticles are anchored on highly conductive Ti_(3)C_(2)MXene co-catalyst by electrostatic self-assembly strategy.The constructed mesoporous TiO_(2)/Ti_(3)C_(2)composites display that the mesoporous TiO_(2)nanoparticles are uniformly distributed on the surface of layer structured Ti_(3)C_(2)nanosheets.More importantly,the as-obtained mesoporous TiO_(2)/Ti_(3)C_(2)composites reveal the significantly enhanced light absorption performance,photo-induced carriers separation and transfer ability,thus boosting the photocatalytic activity.The photocatalytic methyl orange degradation efficiency of mesoporous TiO_(2)/Ti_(3)C_(2)composite with an optimized Ti_(3)C_(2)content(3 wt%)can reach 99.6%within 40 min.The capture experiments of active species confirm that the·O_(2)-and·OH play major role in photocatalytic degradation process.Furthermore,the optimized mesoporous TiO_(2)/Ti_(3)C_(2)composite also shows an excellent photocatalytic H2 production rate of 218.85μmol g^(-1)h^(-1),resulting in a 5.6 times activity as compared with the pristine mesoporous TiO_(2)nanoparticles.This study demonstrates that the MXene family materials can be applied as highly efficient noble-metal-free co-catalysts in the field of photocatalysis.
基金financially supported by the National Science Fund for Distinguished Young Scholars(52025133)the Beijing Natural Science Foundation(JQ18005)+7 种基金the Tencent Foundation through the XPLORER PRIZE,the National Key R&D Program of China(2017YFA0206701)the BIC-ESAT fundingthe financial support of the Central Universities(2232020D-13)the Shanghai Sailing Program(20YF1400700)the National Natural Science Foundation of China(52003045)the financial support from the Young Elite Scientist Sponsorship Program by CAST(2019QNRC001)the“1000-Plan program”of Shaanxi Provincethe“Young Talent Support Plan”of Xi’an Jiaotong University。
文摘High-performance flexible one-dimensional(1D)electrochemical energy storage devices are crucial for the applications of wearable electronics.Although much progress on various 1D energy storage devices has been made,challenges involving fabrication cost,scalability,and efficiency remain.Herein,a highperformance flexible all-fiber zinc-ion battery(ZIB)is fabricated using a low-cost,scalable,and efficient continuous wet-spinning method.Viscous composite inks containing cellulose nanofibers/carbon nanotubes(CNFs/CNTs)binary composite network and either manganese dioxide nanowires(MnO_(2) NWs)or commercial Zn powders are utilized to spinning fiber cathodes and anodes,respectively.MnO_(2) NWs and Zn powders are uniformly dispersed in the interpenetrated CNFs/CNTs fibrous network,leading to homogenous composite inks with an ideal shear-thinning property.The obtained fiber electrodes demonstrate favorable uniformity and flexibility.Benefiting from the well-designed electrodes,the assembled flexible fiber-shaped ZIB delivers a high specific capacity of 281.5 m Ah g^(-1) at 0.25 A g^(-1) and displays excellent cycling stability over 400 cycles.Moreover,the wet-spun fiber-shaped ZIBs achieve ultrahigh gravimetric and volumetric energy densities of 47.3 Wh kg^(-1) and 131.3 m Wh cm^(-3),respectively,based on both cathode and anode and maintain favorable stability even after 4000 bending cycles.This work offers a new concept design of 1D flexible ZIBs that can be potentially incorporated into commercial textiles for wearable and portable electronics.
基金supported in part by the National Natural Science Foundation of China(61803190,61973147,61773188)Liaoning Revitalization Talents Program(XLYC1907050)。
文摘This paper concentrates on asymmetric barrier Lyapunov functions(ABLFs)based on finite-time adaptive neural network(NN)control methods for a class of nonlinear strict feedback systems with time-varying full state constraints.During the process of backstepping recursion,the approximation properties of NNs are exploited to address the problem of unknown internal dynamics.The ABLFs are constructed to make sure that the time-varying asymmetrical full state constraints are always satisfied.According to the Lyapunov stability and finitetime stability theory,it is proven that all the signals in the closedloop systems are uniformly ultimately bounded(UUB)and the system output is driven to track the desired signal as quickly as possible near the origin.In the meantime,in the scope of finitetime,all states are guaranteed to stay in the pre-given range.Finally,a simulation example is proposed to verify the feasibility of the developed finite time control algorithm.
文摘Indoor air quality has a direct impact on human health. Indoor air quality has aroused great concern. This experimental study compares the effects of different water humidification on the indoor particulate pollution characteristics, and analyzes the mass concentration and the particulate number concentration distribution of different sizes of particulates with time under each condition of the purified water humidification, the tap water humidification and the cold boiled water humidification in the office. The results show that under the three kinds of wetting conditions, the concentration of the fine particulates is higher. More minerals are contained in the tap water and the cold boiled water, so the two kinds of humidification have more significant impact on indoor particulate matter. But the purified water humidification has nearly no significant effect on it. The calcium and magnesium ionic compounds are partly removed after the water boiled, so the cold boiled water humidification has less impact on the indoor particulate matter than the tap water humidification. The mass concentration and particulate number concentration of the particle may also be affected due to the frequency of ultrasonic vibration.
基金supported by the National Natural Science Foundation of China(52202102,51972180)the Natural Science Foundation of Shandong Province(ZR2019BB030,ZR2020ME082)+3 种基金the Science and Technology Support Plan for Youth Innovation of Colleges and Universities of Shandong Province(2021KJ056)the Science Fund of Shandong Laboratory of Advanced Materials and Green Manufacturing at Yantai(AMGM2023F13,AMGM2021F05)the Undergraduate Training Program on Innovation and Entrepreneurship of Shandong Province(S202210431016)the Science,Education and Industry Integration of Basic Research Projects of Qilu University of Technology(2023PY022)。
文摘Fibrous nanofluidic materials are ideal building blocks for implantable electrode,biomimetic actuator,wearable electronics due to their favorable features of intrinsic flexibility and unidirectional ion transport.However,the large-scale preparation of fibrous nanofluidic materials with desirable mechanical strength and good environment adaptability for practical use remains challenging.Herein,by fully taking advantage of the attractive mechanical,structural,chemical features of boron nitride(BN)nanosheet and nanofibrillated cellulose(NFC),a scalable and cost-effective three-dimensional(3D)printed macrofiber featuring abundant vertically aligned nanofluidic channels is demonstrated to exhibit a good combination of high tensile strength of 100 MPa,thermal stability of up to 230℃,ionic conductivity of 1.8×10^(−4)S/cm at low salt concentrations(<10^(−3)M).In addition,the versatile surface chemistry of cellulose allows us to stabilize the macrofiber at the molecular level via a facile postcross-linking method,which eventually enables the stable operation of the modified macrofiber in various extreme environments such as strong acidic,strong alkaline,high temperature.We believe this work implies a promising guideline for designing and manufacturing fibrous nanodevices towards extreme environment operations.
基金supported by the National Natural Science Foundation of China (22171219, 22222112)the Innovation Talent Promotion Plan of Shaanxi Province for Science and Technology Innovation Team (2023-CX-TD-51)the Fundamental Research Funds for the Central Universities。
文摘Owing to their appealing three-dimensional structures and tunable photophysical properties, emissive metallacages have been widely applied in recognition and sensing, adsorption and separation, catalysis, etc. Recently, the application of emissive metallacages in biomedical fields has emerged as a hot research topic, because multiple biological functionalities can be facilely integrated into metallacage-based platforms to deliver different functions. In this review, the applications of emissive metallacages in bio-imaging, delivery and cancer theranostics are systematically summarized. The dilemmas and challenges of metallacage-based biomedical materials are also raised at the end of this review. We hope this review would provide some guidance for the construction of novel emissive metallacages with biological functions, and further advance the development of emissive metallacages as biomedical materials.
基金supported by the National Key Research and Development Program of China (2021YFC2400904)the National Science and Technology Major Project of China (2018ZX10102001).
文摘To develop a national reference panel for severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)antigen detection kit and establish a quality standard.The cultures of SARS-CoV-2 and other pathogens were collected to establish a national reference panel for SARS-CoV-2 antigen detection.The stability and homogeneity of the reference panel were evaluated.Based on World Health Organization(WHO)guidance and nucleic acid quantitative results,a quality standard reference panel was established.Currently,three generations of SARS-CoV-2 antigen national reference materials with batch numbers 370095–202001,370095–202202,and 370095–202203 have been successfully established.These national reference panels comprised 8 positive samples,20 negative samples,1 repetitive sample,and 1 lower detection limit sample.The stability and homogeneity of the reference panel meet the requirements.The quality standards are as follows:the positive and negative coincidence rates are 8/8 and 20/20,respectively.The 10 test results of the medium and low-concentration repetitive reference materials should be positive,and the color rendering should be uniform(or the coefficient of variance should not be higher than 20.0%).The lower detection limit should be at least 5×105 U/mL(equivalent to copies/mL),and higher concentrations above the lower detection limit must be positive.A national reference panel for the SARS-CoV-2 antigen detection kit has been established.As the standard of SARS-CoV-2 antigen reagents,the reference panel has played a crucial role in the pre-marketing quality evaluation and post-marketing quality supervision in China.
基金supported by the Natural Key Research and Development Program(No:2021YFA1101604)the key Research and Development program of Hubei province(2022BCA028)the international cooperation project of China Manned Space Program,and program for Tongji Hospital Academic Frontier Youth Team(2019A20)。
文摘Immunity-and-matrix-regulatory cells(IMRCs)derived from human embryonic stem cells have unique abilities in modulating immunity and regulating the extracellular matrix,which could be mass-produced with stable biological properties.Despite resemblance to mesenchymal stem cells(MSCs)in terms of self-renew and tri-lineage differentiation,the ability of IMRCs to repair the meniscus and the underlying mechanism remains undetermined.Here,we showed that IMRCs demonstrated stronger immunomodulatory and pro-regenerative potential than umbilical cord MSCs when stimulated by synovial fluid from patients with meniscus injury.Following injection into the knees of rabbits with meniscal injury,IMRCs enhanced endogenous fibrocartilage regeneration.In the dose-escalating phase I clinical trial(NCT03839238)with eighteen patients recruited,we found that intra-articular IMRCs injection in patients was safe over 12 months post-grafting.Furthermore,the effective results of magnetic resonance imaging(MRI)of meniscus repair and knee functional scores suggested that 5×107 cells are optimal for meniscus injury treatment.In summary,we present the first report of a phase I clinical trial using IMRCs to treat meniscus injury.Our results demonstrated that intra-articular injection of IMRCs is a safe and effective therapy by providing a permissive niche for cartilage regeneration.
基金financially supported by the National Natural Science Foundation of China (Nos. 51972180, 51572134 and 41907315)the Key Technology Research and Development Program of Shandong (No. 2019GGX102070)the Program for Scientific Research Innovation Team in Colleges and Universities of Jinan (No. 2018GXRC006)。
文摘Hollow ternary metal oxides have shown enormous potential in lithium-ion batteries(LIBs),which is ascribed to their complex chemical composition,abundant active defect sites,and the synergy effect be-tween metals.In this work,we synthesized Mo-doped NiCo_(2)O_(4) porous spheres with yolk-shell structure by using a simple self-templating method.Surprisingly,other than the yolk-shell structure we had ob-tained,the inner core of the yolk-shell was also porous,which could fully enhance the electrolyte infil-tration and promote the transmission of lithium ions(Li+)and electrons(e−).The diameter of the porous core in the yolk-shell sphere was about 530 nm,and the outer shell’s thickness was up to 110 nm.In addition,the unique pores in the core appeared in the diameter of about 85 nm.With this structure,the volume expansion of the anode could be well inhibited during charge/discharge.It exhibited prominent electrochemical performance with high reversible capacity(1338 mA h g^(−1) at 100 mA g^(−1)),satisfactory cycle life(1360 mA h g^(−1) after 200 cycles at 100 mA g^(−1)),and exceptional rate capability(820 mA h g^(−1) at 2000 mA g^(−1))as anode material in LIBs.
基金financially supported by the National Natural Science Foundation of China(Nos.52070046,52122009,51808140and 51838005)the Introduced of Innovative R&D Team Project under the“Pearl River Talent Recruitment Program”of Guangdong Province(No.2019ZT08L387)+1 种基金the Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme(Young Scholar)the support from the BL14W1beamline of Shanghai Synchrotron Radiation Facility(SSRF,China)。
文摘Peroxymonosulfate(PMS)activation in heterogeneous processes is a promising water treatment technology.Nevertheless,the high energy consumption and low efficiency during the reaction are ineluctable,due to electron cycling rate limitation.Herein,a new strategy is proposed based on a quantum dots(QDs)/PMS system.Co-ZnS QDs are synthesized by a water phase coprecipitation method.The inequivalent lattice-doping of Co for Zn leads to the generation of surface sulfur vacancies(SVs),which modulates the surface of the catalyst to form an electronic nonequilibrium surface.Astonishingly,the plasticizer micropollutants can be completely degraded within only tens of seconds in the Co-Zn S QDs/PMS system due to this type of surface modulation.The interfacial reaction mechanism is revealed that pollutants tend to be adsorbed on the cobalt metal sites as the electron donors,where the internal electrons of pollutants are captured by the metal species and transferred to the surface SVs.Meanwhile,PMS adsorbed on the SVs is reduced to radicals by capturing electrons,achieving effective electron recovery.Dissolved oxygen(DO)molecules are also easily attracted to catalyst defects and are reduced to O_(2)^(·-),further promoting the degradation of pollutants.
