A solvothermal approach was used to generate N-doped graphene oxide quantum dots(NGOQDs)using MoS_(2) and Al_(2)O_(3)nanocomposites.Through the use of TEM,XRD,Raman,ATR-FTIR,and XPS,the produced composites'shape,c...A solvothermal approach was used to generate N-doped graphene oxide quantum dots(NGOQDs)using MoS_(2) and Al_(2)O_(3)nanocomposites.Through the use of TEM,XRD,Raman,ATR-FTIR,and XPS,the produced composites'shape,composition,and structure were described.Tribological behavior and lubrication properties of NGOQDsMoS_(2) and NGOQDs-Al_(2)O_(3)nanocomposites as additive in nanofluids during hot roll cladding of copper and steel were studied and rolling lubrication mechanism was disclosed.The outcome demonstrates that tribological performance may be greatly enhanced by combining NGOQDs,and surface quality of the rolled copper and steel,and the addition of NGOQDs-MoS_(2) and NGOQDs-Al_(2)O_(3)nanoparticles can further improve the hot-rolling lubrication properties.The tribofilm,formed through the tribochemically induced lubrication process,significantly enhances the wear and corrosion resistance of rolled copper and steel surfaces.展开更多
Metal-based nanomaterials have a wide range of applications in energy conversion,catalysis,bioimaging,and sensors.In our review,we mainly introduce metal nanomaterials-based electrochemical impedance spectroscopy(EIS)...Metal-based nanomaterials have a wide range of applications in energy conversion,catalysis,bioimaging,and sensors.In our review,we mainly introduce metal nanomaterials-based electrochemical impedance spectroscopy(EIS)biosensors in medical healthcare,environmental monitoring,and food safety instructively,with collecting and analyzing the current achievement of predecessors.In general,metal nanomaterials-based EIS biosensors can be divided into four components,in which bioreceptors and metal nanomaterials transducers are vital for designs.Bioreceptors and metal nanomaterials determine the feasibility,specificity,sensitivity and simplicity of manufacturing and operations.With the demonstration and discussion of bioreceptors and metal nanomaterials of biosensors in different fields,our review aims to assist brief acknowledgement of current state-of-the-art achievement and provide our insights for the future development.展开更多
Low-carbon Cr-Mo micro-alloyed deep drawing dual-phase steels were designed in laboratory. As the mi- crostructure and texture evolution in hot-rolled strips and annealed sheets were investigated using SEM, TEM and XR...Low-carbon Cr-Mo micro-alloyed deep drawing dual-phase steels were designed in laboratory. As the mi- crostructure and texture evolution in hot-rolled strips and annealed sheets were investigated using SEM, TEM and XRD technologies, the attribution of solute Mo and MoC particles to DP sheets＇ drawing capacity was investigated. The precipitation thermodynamics were also calculated by Thermo-calc software. Results show that the precipitates in hot-rolled strips mainly are MoC, AIN and MnS, and with the increase of Mo addition, finer and denser MoC par- ticles precipitated in matrix and along grain boundaries of ferrite more easily. Weak textures are shown in the hot- rolled strips, and {112}~110~ and {223}%110~ components tend to be stable in subsequent cold rolling process. During annealing, on one hand, the development of ~lll~//ND texture is suppressed because finer MoC particles prevent the grain boundary migration. On the other hand, unfavorable texture {001 } %110：〉 significantly reduces with Mo increasing, which is attributed to that part of solution C in matrix has been fixed during recrystallization. In addition, the addition of Mo can enhance hardenability strongly and MoC easily re-dissolve at high temperature, which is favor to form martensite in dual-phase steel.展开更多
Iron oxide nanoparticles are the most popular magnetic nanoparticles used in biomedical applications due to their low cost, low toxicity, and unique magnetic property. Magnetic iron oxide nanoparticles, including magn...Iron oxide nanoparticles are the most popular magnetic nanoparticles used in biomedical applications due to their low cost, low toxicity, and unique magnetic property. Magnetic iron oxide nanoparticles, including magnetite （Fe304） and maghemite （γ-Fe203）, usually exhibit a superparamagnetic property as their size goes smaller than 20 nm, which are often denoted as superparamagnetic iron oxide nanoparticles （SPIONs） and utilized for drug delivery, diagnosis, therapy, and etc. This review article gives a brief introduction on magnetic iron oxide nanoparticles in terms of their fundamentals of magnetism, magnetic resonance imaging （MRI）, and drug delivery, as well as the synthesis approaches, surface coating, and application examples from recent key literatures. Because the quality and surface chemistry play important roles in biomedical applications, our review focuses on the synthesis approaches and surface modifications of iron oxide nanopar- ticles. We aim to provide a detailed introduction to readers who are new to this field, helping them to choose suitable synthesis methods and to optimize the surface chemistry of iron oxide nanoparticles for their interests.展开更多
Photoelectrochemical(PEC) water splitting is a promising technology for solar hydrogen production to build a sustainable, renewable and clean energy economy. Given the complexity of the PEC water splitting processes, ...Photoelectrochemical(PEC) water splitting is a promising technology for solar hydrogen production to build a sustainable, renewable and clean energy economy. Given the complexity of the PEC water splitting processes, it is important to note that developing in-situ techniques for studying PEC water splitting presents a formidable challenge. This review is aimed at highlighting advantages and disadvantages of each technique, while offering a pathway of potentially combining several techniques to address different aspects of interfacial processes in PEC water splitting. We reviewed recent progress in various techniques and approaches utilized to study PEC water splitting, focusing on spectroscopic and scanning-probe methods.展开更多
A kind of self-protective flux cored wire has been developed for joining 960 MPa high strength steel. Weld metal containing different aluminium elements contents was obtained by changing the content of aluminum powder...A kind of self-protective flux cored wire has been developed for joining 960 MPa high strength steel. Weld metal containing different aluminium elements contents was obtained by changing the content of aluminum powder in the composition of the flux core. The strength and toughness of weld metal were tested by tensile test and impact test at different temperatures, and the influence mechanism of aluminium element on the microstructure and mechanical properties of weld metal was analyzed by means of metallographic microstructure observation and scanning electron microscope observation. The results show that aluminium element content on impact ductility of weld metal of 960 MPa high strength steel is great, but the influence on tensile strength and elongation of weld metal is little. With increasing aluminium element contents of weld metal, the impact energy of weld metal increases at first and then decreases, the best aluminium element content of weld metal is 0.2 wt.%. Aluminium oxide is easy to be formed in weld metal with low aluminium element contents, and the aluminium oxide can easily become nucleation particle for acicular ferrite. It is conducive to formation more acicular ferrite and will improve impact absorbing energy of weld metal. Aluminium nitride will easily formed in weld metal with high aluminium element content, and the coarse ferrite microstructure appears in weld metal and reduces impact energy of weld metal.展开更多
Effects of Zn, Zn-Al and Zn-P additions on melting points, microstructures, tensile properties, and oxidation behaviors of Sn-40 Bi lead-free solder were investigated. The experimental results show that the addition o...Effects of Zn, Zn-Al and Zn-P additions on melting points, microstructures, tensile properties, and oxidation behaviors of Sn-40 Bi lead-free solder were investigated. The experimental results show that the addition of these three types of elements can refine the microstructures and improve the ultimate tensile strength（UTS） of solder alloys. The fractographic analysis illustrates that ductile fracture is the dominant failure mode in tensile tests of Sn-40Bi-2Zn（SBZ）and Sn-40Bi-2Zn-0.005Al（SBZA） specimens, while brittle fracture is the controlled manner in Sn-40Bi-2Zn-0.005P（SBZP） and Sn-58 Bi solders. XPS analysis indicates that trace amounts of both Al and P additives in solder can improve the antioxidant capacity, whereas only the additive of Al in solder can reduce the thickness of oxidation film.展开更多
Using the one-atom theory(OA), the atomic states of Ru-electrocatalyst with hcp structure was determined as [Kr](4dn)3.78(4dc)2.22(5sc)1.77(5sf)0.23. The potential curve, elasticity and the temperature dependence of l...Using the one-atom theory(OA), the atomic states of Ru-electrocatalyst with hcp structure was determined as [Kr](4dn)3.78(4dc)2.22(5sc)1.77(5sf)0.23. The potential curve, elasticity and the temperature dependence of linear thermal expansion coefficient and bulk modulus of hcp-Ru were calculated quantitatively. The atomic states of this metal with fcc and bcc structure and liquid state were also studied. According to its atomic states, the relationship between the atomic states and catalytic performance was explained qualitatively and these supplied Ru-metal and electrocatalyst with complete data for optimum designation in accordance with metal material systematic sicence.展开更多
The composites comprising Fe-carbon nanotubes(CNTs) on TiO2 were prepared by a modified sol-gel method and characterized by nitrogen adsorption,scanning electron microscopy,transmission electron microscopy,X-ray diffr...The composites comprising Fe-carbon nanotubes(CNTs) on TiO2 were prepared by a modified sol-gel method and characterized by nitrogen adsorption,scanning electron microscopy,transmission electron microscopy,X-ray diffraction,and energy dispersive X-ray analysis.The photocatalytic decomposition of rhodamine B(Rh.B) under UV irradiation and air aeration catalyzed by the composites was measured.The photocatalytic activity of TiO2 nanoparticles was significantly enhanced by the large CNT network that facilitated electron transfer between adsorbed Rh.B molecules and the catalyst substrate and the simultaneous occurrence of the photo-Fenton reaction in the presence of Fe particles.A marked acceleration of the decomposition rate was observed with aeration by flowing air aeration due to the formation of the circulatory photo-Fenton system.Chemical oxygen demand of piggery waste was measured at regular intervals to evaluate the mineralization of wastewater.展开更多
Based on the deformation characteristics of Y-type mill,a finite element model for simulating the formation process of shaped steel tube for driving shaft is proposed.The distributions of stress and strain were obtain...Based on the deformation characteristics of Y-type mill,a finite element model for simulating the formation process of shaped steel tube for driving shaft is proposed.The distributions of stress and strain were obtained from the simulation.The outer diameter and transverse wall thickness were also analyzed quantitatively.Experiment was done on Y-type mill.A comparison between simulation results and experiment results shows that the simulated results of shaped steel tube are in good agreement with the on-site data.The model could provide the basis for theoretical research and engineering applications of shaped steel tube rolling process.展开更多
We investigate the upconversion emission of CaWO4:Tm^(3+)/Yb^(3+)polycrystals prepared by the high-temperature solid-state method.The crystal structure of the polycrystals is characterized by means of x-ray diffractio...We investigate the upconversion emission of CaWO4:Tm^(3+)/Yb^(3+)polycrystals prepared by the high-temperature solid-state method.The crystal structure of the polycrystals is characterized by means of x-ray diffraction.Under the excitation of a 980 nm continuous wave diode laser,the samples show intense blue upconversion emissions centered at 473 nm,corresponding to the ^(1)G4→^(3)H_(6) transition of Tm^(3+).The dependence of the upconversion emission intensity on the pump power of a laser diode is measured,and the results indicate that the two-photon and three-photon processes contribute simultaneously to the blue upconversion emissions.The possible multi-photon upconversion process and upconversion mechanisms are discussed.展开更多
Polyvinylpyrrolidone （PVP） nanofibers were processed by magnetic-field-assisted electrospinning （MFAES） technique. Since electric field intensity was one of the most important parameters influencing fiber morpholo...Polyvinylpyrrolidone （PVP） nanofibers were processed by magnetic-field-assisted electrospinning （MFAES） technique. Since electric field intensity was one of the most important parameters influencing fiber morphology, the research aimed to study how electric field intensity affects fiber morphology in MFAES technique. The experimental results revealed that the distribution of diameter widened while the average diameter of PVP fibers decreased and the degree of the alignment reduced with the increase of electric field intensity. However, the fibers would be conglutinated together when the electric field intensity was too low. Also, the increase of working distance made the average diameter and the degree of the alignment increase slightly under the same electric field intensity, but the fibers could be partially curved instead of being fully straight if the working distance was too long. It was also indicated that maintaining the electric field intensity at 1 kV/cm With the voltage-distance combinations of 12 kV-12 cm （for 12wt% PVP） and 15 kV-15 cm （for 14wt% PVP） among all other combinations would result in the optimal alignment as well as a narrow size distribution of the fibers.展开更多
With rollers as elastic bodies and workpieces as elastoplastic bodies,the rolling problem can be viewed as a friction elastic-plastic contact problem.With fewer assumptions in the simulation of strip-rolling process,a...With rollers as elastic bodies and workpieces as elastoplastic bodies,the rolling problem can be viewed as a friction elastic-plastic contact problem.With fewer assumptions in the simulation of strip-rolling process,a boundary element method（BEM）for two-dimensional elastoplastic finite strain and finite deformation analysis of contact problems with friction was presented.All the equations for contact problems,which include multi-nonlinearities,were obtained.Incremental and iterative procedures were used to find contact pressure and friction stress.Moreover,initial strain rate algorithm and work-hardening material behavior can be assumed in the plastic analysis.Several examples were presented,and the results of contact pressure and friction stress were in excellent agreement with those of analysis.展开更多
To study the mechanism of burnt damage of oil film bearing in high-speed wire rolling mill,reasonable tempera-ture sensors are designed and calibrated,pressure block of rolling mill has been transformed into pressure ...To study the mechanism of burnt damage of oil film bearing in high-speed wire rolling mill,reasonable tempera-ture sensors are designed and calibrated,pressure block of rolling mill has been transformed into pressure sensors.Online tempera-ture and load of oil film bearing in a domestic precision rolling F15 have been tested.Consequently,a large sum of valuable test data was obtained.The distributions rules of pressure and temperature under continuous online rolling state are recorded in detail.Theoretical and experimental results are beneficial to damage mechanism of oil film bearing,thus its service life could be pro-longed.Moreover,such results could provide an important reference for online test and control.展开更多
The present study uses power data from panel meter connected to the micro-grid to identify electrical energy consumption of the school appliances and their behavior in both warm-up, standby and active operation states...The present study uses power data from panel meter connected to the micro-grid to identify electrical energy consumption of the school appliances and their behavior in both warm-up, standby and active operation states. Before the conduction of experiments a load auditing of the school appliances was carried out by reading the rated power of each device (e.g. photocopy machine, printer, and fridge). The captures of this kind of information were essential as it provides a starting point to determine energy use of each appliance and hence simplify the process of identification. The electric parameters such as active power, reactive power and current were used to analyze the behavior of electrical appliances in all states. Experimental results show that, both active and reactive power were found to be high for old Canon photocopy machine as compared to new Canon photocopy machine. Another experiment reveals that printing one copy by using HP laser printer consumes about 700 W, while photocopying one copy with new Canon machine utilizes approximately 1100 W. This study concludes that new photocopy machine consumes more electric energy in warm-up state as compared to other states (standby and active operation states). Future work is to develop an algorithm for demand side management strategies which will enable efficient utilization of the electric energy from the micro-grid and hence bring the intended energy impact to the school.展开更多
A multifunctional drug delivery system（GNRs@mSiO_2-HA-RGD） was developed by conjugating targeting ligand hyaluronic acid（HA） and RGD with mesoporous silica-coated gold nanorods（GNRs@mSiO_2） for dual-targeted che...A multifunctional drug delivery system（GNRs@mSiO_2-HA-RGD） was developed by conjugating targeting ligand hyaluronic acid（HA） and RGD with mesoporous silica-coated gold nanorods（GNRs@mSiO_2） for dual-targeted chemo-photothermal therapy. The physiochemical properties of the prepared nanoparticles were characterized by FTIR, UV-vis spectra, and ~1H NMR. Doxorubicin hydrochloride（DOX）, an anticancer drug, was used as the model drug to investigate the drug loading, in vitro drug release profiles and cytotoxicity. The experimental results show that DOX-GNRs@mSiO_2-HA-RGD is synthesized with a mean diameter of 116 nm and a sufficient load capacity of about 19.8%. It also has p H-enzyme sensitive and NIRtriggered drug release manner. Cellular uptake indicates that DOX-GNRs@mSiO_2-HA-RGD exhibits a higher cellular uptake via CD44 receptor and integrin receptor mediated endocytosis compared with the GNRs@mSiO_2 modified with one receptor or no receptor. In comparison with chemotherapy or photothermal therapy alone, DOX-GNRs@mSiO_2-HA-RGD displayes the synergistic effects and achieves a higher therapeutic efficacy. It can be expected that DOX-GNRs@mSiO_2-HA-RGD is a potential dual-targeted chemo-photothermal therapeutic platform for effective cancer treatment.展开更多
A new technique to reduce the influence of metallic carbon nanotubes(CNTs)relevant for large-scale integrated circuits based on CNT-nanonet transistorsis proposed and verified.Historically,electrical and chemical filt...A new technique to reduce the influence of metallic carbon nanotubes(CNTs)relevant for large-scale integrated circuits based on CNT-nanonet transistorsis proposed and verified.Historically,electrical and chemical filtering of the metallic CNTs have been used to improve the ON/OFF ratio of CNT-nanonet transistors;however,the corresponding degradation in ON-current has made these techniques somewhat unsatisfactory.Here,we abandon the classical approaches in favor of a new approach based on relocation of asymmetric percolation threshold of CNT-nanonet transistors by a technique called“striping”;this allows fabrication of transistors with ON/OFF ratio>1000 and ON-current degradation no more than a factor of 2.We offer first principle numerical models,experimental confirmation,and renormalization arguments to provide a broad theoretical and experimental foundation of the proposed method.展开更多
Two-dimensional（2D） layered materials,such as graphene,hexagonal boron nitride（h-BN）,molybdenum disulfide（Mo S_2/,have attracted tremendous interest due to their atom-thickness structures and excellent physical p...Two-dimensional（2D） layered materials,such as graphene,hexagonal boron nitride（h-BN）,molybdenum disulfide（Mo S_2/,have attracted tremendous interest due to their atom-thickness structures and excellent physical properties.h-BN has predominant advantages as the dielectric substrate in FET devices due to its outstanding properties such as chemically inert surface,being free of dangling bonds and surface charge traps,especially the large-band-gap insulativity.h-BN involved vertical heterostructures have been widely exploited during the past few years.Such heterostructures adopting h-BN as dielectric layers exhibit enhanced electronic performance,and provide further possibilities for device engineering.Besides,a series of intriguing physical phenomena are observed in certain vertical heterostructures,such as superlattice potential induced replication of Dirac points,band gap tuning,Hofstadter butterfly states,gate-dependent pseudospin mixing.Herein we focus on the rapid developments of h-BN synthesis and fabrication of vertical heterostructures devices based on h-BN,and review the novel properties as well as the potential applications of the heterostructures composed of h-BN.展开更多
An intriguing topic in heterogeneous catalysis is the metal-support interaction(MSI),in which the typical role of the support is to disperse and stabilize metal particles and charge exchange between the metal and supp...An intriguing topic in heterogeneous catalysis is the metal-support interaction(MSI),in which the typical role of the support is to disperse and stabilize metal particles and charge exchange between the metal and support.However,MSI remains elusive.To map out how the interaction dictates catalytic performance,metal catalysts with atomic precision and their combination with well-defined supports can provide new insights into the catalysis of supported metal catalysts.Atomically precise metal clusters have emerged as a novel catalytic material with a crystallographic structure that offers access to a fundamental understanding of MSI.This review systematically classifies supported cluster catalysts based on interaction strength into four categories:weak interaction(e.g.,van der Waals forces),physical confinement,electrostatic interaction,and strong covalent anchoring.We highlight their unique catalytic behaviors in hydrogenation,oxidation,CO_(2)conversion,photocatalytic,and electrocatalytic reactions.The support-mediated catalytic enhancement mechanisms are elucidated through representative works,including dual-site synergistic activation,oxygen vacancy-mediated activation,hydrogen spillover facilitating proton transfer,and tandem catalysis.Finally,we also identify current challenges in supported cluster catalysts,while outlining promising pathways for industrial application in sustainable energy and environmental catalysis.The systematic analysis of structure-performance correlation will provide valuable guidance for designing high-performance supported metal catalysts.展开更多
基金the support provided by the Natural Science Foundation of Jiangsu(No.BK20231355)the major project of Nanjing Institute of Technology,China Innovation Fund(No.CKJA202201)Qinglan Project of Jiangsu Province,the Major project of Basic Science(Natural science)research in colleges and universities of Jiangsu Province(No.23KJA430009)。
文摘A solvothermal approach was used to generate N-doped graphene oxide quantum dots(NGOQDs)using MoS_(2) and Al_(2)O_(3)nanocomposites.Through the use of TEM,XRD,Raman,ATR-FTIR,and XPS,the produced composites'shape,composition,and structure were described.Tribological behavior and lubrication properties of NGOQDsMoS_(2) and NGOQDs-Al_(2)O_(3)nanocomposites as additive in nanofluids during hot roll cladding of copper and steel were studied and rolling lubrication mechanism was disclosed.The outcome demonstrates that tribological performance may be greatly enhanced by combining NGOQDs,and surface quality of the rolled copper and steel,and the addition of NGOQDs-MoS_(2) and NGOQDs-Al_(2)O_(3)nanoparticles can further improve the hot-rolling lubrication properties.The tribofilm,formed through the tribochemically induced lubrication process,significantly enhances the wear and corrosion resistance of rolled copper and steel surfaces.
基金financially sponsored by the National Natural Science Foundation of China(Nos.51672204 and 22102128)UK NERC Fellowship Grant(No.NE/R013349/2)。
文摘Metal-based nanomaterials have a wide range of applications in energy conversion,catalysis,bioimaging,and sensors.In our review,we mainly introduce metal nanomaterials-based electrochemical impedance spectroscopy(EIS)biosensors in medical healthcare,environmental monitoring,and food safety instructively,with collecting and analyzing the current achievement of predecessors.In general,metal nanomaterials-based EIS biosensors can be divided into four components,in which bioreceptors and metal nanomaterials transducers are vital for designs.Bioreceptors and metal nanomaterials determine the feasibility,specificity,sensitivity and simplicity of manufacturing and operations.With the demonstration and discussion of bioreceptors and metal nanomaterials of biosensors in different fields,our review aims to assist brief acknowledgement of current state-of-the-art achievement and provide our insights for the future development.
基金Item Sponsored by National Natural Science Foundation of China(50904006)The Fundamental Research Funds for the Central Universities of China(FRT-TP-10-001A)
文摘Low-carbon Cr-Mo micro-alloyed deep drawing dual-phase steels were designed in laboratory. As the mi- crostructure and texture evolution in hot-rolled strips and annealed sheets were investigated using SEM, TEM and XRD technologies, the attribution of solute Mo and MoC particles to DP sheets＇ drawing capacity was investigated. The precipitation thermodynamics were also calculated by Thermo-calc software. Results show that the precipitates in hot-rolled strips mainly are MoC, AIN and MnS, and with the increase of Mo addition, finer and denser MoC par- ticles precipitated in matrix and along grain boundaries of ferrite more easily. Weak textures are shown in the hot- rolled strips, and {112}~110~ and {223}%110~ components tend to be stable in subsequent cold rolling process. During annealing, on one hand, the development of ~lll~//ND texture is suppressed because finer MoC particles prevent the grain boundary migration. On the other hand, unfavorable texture {001 } %110：〉 significantly reduces with Mo increasing, which is attributed to that part of solution C in matrix has been fixed during recrystallization. In addition, the addition of Mo can enhance hardenability strongly and MoC easily re-dissolve at high temperature, which is favor to form martensite in dual-phase steel.
基金Project supported by Start-up Grant of Nanyang Technological UniversityTier 1 Grant of Ministry of Education,Singapore(RGT8/13)
文摘Iron oxide nanoparticles are the most popular magnetic nanoparticles used in biomedical applications due to their low cost, low toxicity, and unique magnetic property. Magnetic iron oxide nanoparticles, including magnetite （Fe304） and maghemite （γ-Fe203）, usually exhibit a superparamagnetic property as their size goes smaller than 20 nm, which are often denoted as superparamagnetic iron oxide nanoparticles （SPIONs） and utilized for drug delivery, diagnosis, therapy, and etc. This review article gives a brief introduction on magnetic iron oxide nanoparticles in terms of their fundamentals of magnetism, magnetic resonance imaging （MRI）, and drug delivery, as well as the synthesis approaches, surface coating, and application examples from recent key literatures. Because the quality and surface chemistry play important roles in biomedical applications, our review focuses on the synthesis approaches and surface modifications of iron oxide nanopar- ticles. We aim to provide a detailed introduction to readers who are new to this field, helping them to choose suitable synthesis methods and to optimize the surface chemistry of iron oxide nanoparticles for their interests.
基金funding support from the National Science Foundation (DMR#1254600)resources of the Center for Functional Nanomaterials, which is a U.S. DOE Office of Science Facility, at the Brookhaven National Laboratory under Contract No. DE-SC0012704
文摘Photoelectrochemical(PEC) water splitting is a promising technology for solar hydrogen production to build a sustainable, renewable and clean energy economy. Given the complexity of the PEC water splitting processes, it is important to note that developing in-situ techniques for studying PEC water splitting presents a formidable challenge. This review is aimed at highlighting advantages and disadvantages of each technique, while offering a pathway of potentially combining several techniques to address different aspects of interfacial processes in PEC water splitting. We reviewed recent progress in various techniques and approaches utilized to study PEC water splitting, focusing on spectroscopic and scanning-probe methods.
基金Project was supported by the 2019 Scientific Research Foundation of Liaoning Provincial Education Department (Grant No. LJJF201902)Special Research Foundation of Liaoning Equipment Manufacture College of Vocational and Technology (Grant No.2018YYYJ-5)。
文摘A kind of self-protective flux cored wire has been developed for joining 960 MPa high strength steel. Weld metal containing different aluminium elements contents was obtained by changing the content of aluminum powder in the composition of the flux core. The strength and toughness of weld metal were tested by tensile test and impact test at different temperatures, and the influence mechanism of aluminium element on the microstructure and mechanical properties of weld metal was analyzed by means of metallographic microstructure observation and scanning electron microscope observation. The results show that aluminium element content on impact ductility of weld metal of 960 MPa high strength steel is great, but the influence on tensile strength and elongation of weld metal is little. With increasing aluminium element contents of weld metal, the impact energy of weld metal increases at first and then decreases, the best aluminium element content of weld metal is 0.2 wt.%. Aluminium oxide is easy to be formed in weld metal with low aluminium element contents, and the aluminium oxide can easily become nucleation particle for acicular ferrite. It is conducive to formation more acicular ferrite and will improve impact absorbing energy of weld metal. Aluminium nitride will easily formed in weld metal with high aluminium element content, and the coarse ferrite microstructure appears in weld metal and reduces impact energy of weld metal.
基金financially supported by the Natural Science Fund for Colleges and Universities in Jiangsu Province (Nos. 11KJB460003 and 12KJB460003)Jiangsu Planning Project of Science and Technology (No. SBK201241936)National Natural Science Foundation of China (No. 51201072)
文摘Effects of Zn, Zn-Al and Zn-P additions on melting points, microstructures, tensile properties, and oxidation behaviors of Sn-40 Bi lead-free solder were investigated. The experimental results show that the addition of these three types of elements can refine the microstructures and improve the ultimate tensile strength（UTS） of solder alloys. The fractographic analysis illustrates that ductile fracture is the dominant failure mode in tensile tests of Sn-40Bi-2Zn（SBZ）and Sn-40Bi-2Zn-0.005Al（SBZA） specimens, while brittle fracture is the controlled manner in Sn-40Bi-2Zn-0.005P（SBZP） and Sn-58 Bi solders. XPS analysis indicates that trace amounts of both Al and P additives in solder can improve the antioxidant capacity, whereas only the additive of Al in solder can reduce the thickness of oxidation film.
基金Project(50271085 50471058) supported by the National Natural Science Foundation of China Project(04FJ2002) supported by the Natural Science Foundation of Hunan Province, China
文摘Using the one-atom theory(OA), the atomic states of Ru-electrocatalyst with hcp structure was determined as [Kr](4dn)3.78(4dc)2.22(5sc)1.77(5sf)0.23. The potential curve, elasticity and the temperature dependence of linear thermal expansion coefficient and bulk modulus of hcp-Ru were calculated quantitatively. The atomic states of this metal with fcc and bcc structure and liquid state were also studied. According to its atomic states, the relationship between the atomic states and catalytic performance was explained qualitatively and these supplied Ru-metal and electrocatalyst with complete data for optimum designation in accordance with metal material systematic sicence.
文摘The composites comprising Fe-carbon nanotubes(CNTs) on TiO2 were prepared by a modified sol-gel method and characterized by nitrogen adsorption,scanning electron microscopy,transmission electron microscopy,X-ray diffraction,and energy dispersive X-ray analysis.The photocatalytic decomposition of rhodamine B(Rh.B) under UV irradiation and air aeration catalyzed by the composites was measured.The photocatalytic activity of TiO2 nanoparticles was significantly enhanced by the large CNT network that facilitated electron transfer between adsorbed Rh.B molecules and the catalyst substrate and the simultaneous occurrence of the photo-Fenton reaction in the presence of Fe particles.A marked acceleration of the decomposition rate was observed with aeration by flowing air aeration due to the formation of the circulatory photo-Fenton system.Chemical oxygen demand of piggery waste was measured at regular intervals to evaluate the mineralization of wastewater.
文摘Based on the deformation characteristics of Y-type mill,a finite element model for simulating the formation process of shaped steel tube for driving shaft is proposed.The distributions of stress and strain were obtained from the simulation.The outer diameter and transverse wall thickness were also analyzed quantitatively.Experiment was done on Y-type mill.A comparison between simulation results and experiment results shows that the simulated results of shaped steel tube are in good agreement with the on-site data.The model could provide the basis for theoretical research and engineering applications of shaped steel tube rolling process.
文摘We investigate the upconversion emission of CaWO4:Tm^(3+)/Yb^(3+)polycrystals prepared by the high-temperature solid-state method.The crystal structure of the polycrystals is characterized by means of x-ray diffraction.Under the excitation of a 980 nm continuous wave diode laser,the samples show intense blue upconversion emissions centered at 473 nm,corresponding to the ^(1)G4→^(3)H_(6) transition of Tm^(3+).The dependence of the upconversion emission intensity on the pump power of a laser diode is measured,and the results indicate that the two-photon and three-photon processes contribute simultaneously to the blue upconversion emissions.The possible multi-photon upconversion process and upconversion mechanisms are discussed.
基金Fund by the Youth Foundation of the North University of China(2012)the Project of Graduate Innovation of Shanxi Province(20133102)
文摘Polyvinylpyrrolidone （PVP） nanofibers were processed by magnetic-field-assisted electrospinning （MFAES） technique. Since electric field intensity was one of the most important parameters influencing fiber morphology, the research aimed to study how electric field intensity affects fiber morphology in MFAES technique. The experimental results revealed that the distribution of diameter widened while the average diameter of PVP fibers decreased and the degree of the alignment reduced with the increase of electric field intensity. However, the fibers would be conglutinated together when the electric field intensity was too low. Also, the increase of working distance made the average diameter and the degree of the alignment increase slightly under the same electric field intensity, but the fibers could be partially curved instead of being fully straight if the working distance was too long. It was also indicated that maintaining the electric field intensity at 1 kV/cm With the voltage-distance combinations of 12 kV-12 cm （for 12wt% PVP） and 15 kV-15 cm （for 14wt% PVP） among all other combinations would result in the optimal alignment as well as a narrow size distribution of the fibers.
基金Item Sponsored by National Natural Science Foundation of China(50575155)
文摘With rollers as elastic bodies and workpieces as elastoplastic bodies,the rolling problem can be viewed as a friction elastic-plastic contact problem.With fewer assumptions in the simulation of strip-rolling process,a boundary element method（BEM）for two-dimensional elastoplastic finite strain and finite deformation analysis of contact problems with friction was presented.All the equations for contact problems,which include multi-nonlinearities,were obtained.Incremental and iterative procedures were used to find contact pressure and friction stress.Moreover,initial strain rate algorithm and work-hardening material behavior can be assumed in the plastic analysis.Several examples were presented,and the results of contact pressure and friction stress were in excellent agreement with those of analysis.
基金Funded by the Natural Science Foundation of China(50575155)Shanxi younger science foundation(20031041).
文摘To study the mechanism of burnt damage of oil film bearing in high-speed wire rolling mill,reasonable tempera-ture sensors are designed and calibrated,pressure block of rolling mill has been transformed into pressure sensors.Online tempera-ture and load of oil film bearing in a domestic precision rolling F15 have been tested.Consequently,a large sum of valuable test data was obtained.The distributions rules of pressure and temperature under continuous online rolling state are recorded in detail.Theoretical and experimental results are beneficial to damage mechanism of oil film bearing,thus its service life could be pro-longed.Moreover,such results could provide an important reference for online test and control.
文摘The present study uses power data from panel meter connected to the micro-grid to identify electrical energy consumption of the school appliances and their behavior in both warm-up, standby and active operation states. Before the conduction of experiments a load auditing of the school appliances was carried out by reading the rated power of each device (e.g. photocopy machine, printer, and fridge). The captures of this kind of information were essential as it provides a starting point to determine energy use of each appliance and hence simplify the process of identification. The electric parameters such as active power, reactive power and current were used to analyze the behavior of electrical appliances in all states. Experimental results show that, both active and reactive power were found to be high for old Canon photocopy machine as compared to new Canon photocopy machine. Another experiment reveals that printing one copy by using HP laser printer consumes about 700 W, while photocopying one copy with new Canon machine utilizes approximately 1100 W. This study concludes that new photocopy machine consumes more electric energy in warm-up state as compared to other states (standby and active operation states). Future work is to develop an algorithm for demand side management strategies which will enable efficient utilization of the electric energy from the micro-grid and hence bring the intended energy impact to the school.
基金Funded by the National Natural Science Foundation of China(Nos.51473130 and 51572206)the Wuhan Huanghe excellence plan and Entrepreneurship Training Program of Wuhan University and Technology(Nos.20171049720018,20171049720019,and 20171049720009)
文摘A multifunctional drug delivery system（GNRs@mSiO_2-HA-RGD） was developed by conjugating targeting ligand hyaluronic acid（HA） and RGD with mesoporous silica-coated gold nanorods（GNRs@mSiO_2） for dual-targeted chemo-photothermal therapy. The physiochemical properties of the prepared nanoparticles were characterized by FTIR, UV-vis spectra, and ~1H NMR. Doxorubicin hydrochloride（DOX）, an anticancer drug, was used as the model drug to investigate the drug loading, in vitro drug release profiles and cytotoxicity. The experimental results show that DOX-GNRs@mSiO_2-HA-RGD is synthesized with a mean diameter of 116 nm and a sufficient load capacity of about 19.8%. It also has p H-enzyme sensitive and NIRtriggered drug release manner. Cellular uptake indicates that DOX-GNRs@mSiO_2-HA-RGD exhibits a higher cellular uptake via CD44 receptor and integrin receptor mediated endocytosis compared with the GNRs@mSiO_2 modified with one receptor or no receptor. In comparison with chemotherapy or photothermal therapy alone, DOX-GNRs@mSiO_2-HA-RGD displayes the synergistic effects and achieves a higher therapeutic efficacy. It can be expected that DOX-GNRs@mSiO_2-HA-RGD is a potential dual-targeted chemo-photothermal therapeutic platform for effective cancer treatment.
基金the Network for Computational Nanotechnology and the Lilly Foundation for financial supportthe National Science Foundation(NIRT-0403489)+1 种基金the Department of Energy(DE-FG02-07ER46471)Motorola,Inc.,the Frederick-Seitz Materials Research Laboratory,and the Center for Microanalysis of Materials(DE-FG02-07ER46453 and DE-FG02-07ER46471)at the University of Illinois.
文摘A new technique to reduce the influence of metallic carbon nanotubes(CNTs)relevant for large-scale integrated circuits based on CNT-nanonet transistorsis proposed and verified.Historically,electrical and chemical filtering of the metallic CNTs have been used to improve the ON/OFF ratio of CNT-nanonet transistors;however,the corresponding degradation in ON-current has made these techniques somewhat unsatisfactory.Here,we abandon the classical approaches in favor of a new approach based on relocation of asymmetric percolation threshold of CNT-nanonet transistors by a technique called“striping”;this allows fabrication of transistors with ON/OFF ratio>1000 and ON-current degradation no more than a factor of 2.We offer first principle numerical models,experimental confirmation,and renormalization arguments to provide a broad theoretical and experimental foundation of the proposed method.
基金Project supported by the National Natural Science Foundation of China(Nos.61390502,21373068)the National Basic Research Program of China(No.2013CB632900)+1 种基金the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(No.51521003)the Self-Planned Task of State Key Laboratory of Robotics and System(No.SKLRS201607B)
文摘Two-dimensional（2D） layered materials,such as graphene,hexagonal boron nitride（h-BN）,molybdenum disulfide（Mo S_2/,have attracted tremendous interest due to their atom-thickness structures and excellent physical properties.h-BN has predominant advantages as the dielectric substrate in FET devices due to its outstanding properties such as chemically inert surface,being free of dangling bonds and surface charge traps,especially the large-band-gap insulativity.h-BN involved vertical heterostructures have been widely exploited during the past few years.Such heterostructures adopting h-BN as dielectric layers exhibit enhanced electronic performance,and provide further possibilities for device engineering.Besides,a series of intriguing physical phenomena are observed in certain vertical heterostructures,such as superlattice potential induced replication of Dirac points,band gap tuning,Hofstadter butterfly states,gate-dependent pseudospin mixing.Herein we focus on the rapid developments of h-BN synthesis and fabrication of vertical heterostructures devices based on h-BN,and review the novel properties as well as the potential applications of the heterostructures composed of h-BN.
基金the National Natural Science Foundation of China(grant nos.22125202,92461312,U24A20487,92361201)China Petroleum and Chemical Corporation(SINOPEC)the Research Institute of Petroleum Processing Co.,Ltd.,China.
文摘An intriguing topic in heterogeneous catalysis is the metal-support interaction(MSI),in which the typical role of the support is to disperse and stabilize metal particles and charge exchange between the metal and support.However,MSI remains elusive.To map out how the interaction dictates catalytic performance,metal catalysts with atomic precision and their combination with well-defined supports can provide new insights into the catalysis of supported metal catalysts.Atomically precise metal clusters have emerged as a novel catalytic material with a crystallographic structure that offers access to a fundamental understanding of MSI.This review systematically classifies supported cluster catalysts based on interaction strength into four categories:weak interaction(e.g.,van der Waals forces),physical confinement,electrostatic interaction,and strong covalent anchoring.We highlight their unique catalytic behaviors in hydrogenation,oxidation,CO_(2)conversion,photocatalytic,and electrocatalytic reactions.The support-mediated catalytic enhancement mechanisms are elucidated through representative works,including dual-site synergistic activation,oxygen vacancy-mediated activation,hydrogen spillover facilitating proton transfer,and tandem catalysis.Finally,we also identify current challenges in supported cluster catalysts,while outlining promising pathways for industrial application in sustainable energy and environmental catalysis.The systematic analysis of structure-performance correlation will provide valuable guidance for designing high-performance supported metal catalysts.
