Developing new understanding of photoelectrochemical water splitting via in-situ techniques:A review on recent progress

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.

Magnetic iron oxide nanoparticles: Synthesis and surface coating techniques for biomedical applications

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.

Effect of aluminium element on microstructure and properties of weld metal of 960 MPa steel

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.

Atomic states and properties of Ru-electrocatalyst

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.

紫外光照射下Fe-碳纳米管/TiO_2复合材料降解罗丹明B(英文)

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.

Recent advances on bioreceptors and metal nanomaterials——based electrochemical impedance spectroscopy biosensors

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.

Blue Upconversion Luminescence in Tm^(3+)/Yb^(3+) Codoped CaWO_(4) Polycrystals

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.

Effect of Electric Field Intensity on the Morphology of Magnetic-field-assisted Electrospinning PVP Nanofibers

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.

An Experimental Study of Electrical Appliances Consumption Using Panel Meter Data

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.

Hyaluronic Acid-RGD Peptide Conjugated Mesoporous Silica-coated Gold Nanorods for Cancer Dual-targeted Chemo-photothermal Therapy

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.

Precipitation Behavior and Textural Evolution of Cold-Rolled High Strength Deep Drawing Dual-Phase Steels

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.

Theory and Practice of“Striping”for Improved ON/OFF Ratio in Carbon Nanonet Thin Film Transistors

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.

Effects of Zn, Zn-Al and Zn-P Additions on the Tensile Properties of Sn-Bi Solder

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.

Recent advances in preparation,properties and device applications of twodimensional h-BN and its vertical heterostructures

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.

Finite Element Simulation of Cold-Rolling Process of Shaped Steel Tube for Driving Shaft

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.

Mono-dispersed Ag nanoparticles decorated graphitic carbon nitride:An excellent lubricating additive as PPESK composite film

Studies show that two dimensional(2D)nanomaterial and its hybrid have a great promise in tribology for the special laminar microstructure.However,the majority of performed investigations about 2D graphitic carbon nitride(g-C_(3)N_(4))nanosheets are most focused on energy storage,catalysis,adsorption,rarely tribology.In the present study,g-C_(3)N_(4) supporting mono-dispersed Ag nanoparticle hybrid(g-C_(3)N_(4)/Ag)is prepared,and its microstructure and chemical composition are determined.More specifically,the tribological performance as the lubricating additive of poly phthalazinone ether sulfone ketone(PPESK)composite is investigated using the ball-on-disc friction tester.Moreover,the corresponding enhancement mechanism is well proposed based on the experimental analysis and theoretical simulation.Obtained results show that Ag nanoparticles with a size of about 10-20 nm are homogeneously anchored on g-C_(3)N_(4) nanosheets,favoring for good compatibility between g-C_(3)N_(4)/Ag and PPESK.It is found that when 0.3 wt%of g-C_(3)N_(4)/Ag is added to PPESK,the friction coefficient and wear rate of PPESK decrease by 68.9%and 97.1%,respectively.These reductions are mainly attributed to the synergistic self-lubricating effect of Ag nanoparticles and g-C_(3)N_(4) nanosheet,the formation of transfer film,as well as the limited effect of g-C_(3)N_(4)/Ag on the shear deformation of PPESK composite film.Furthermore,it is found that the proposed g-C_(3)N_(4)/Ag-PPESK composite still keeps reasonable friction-reducing and wear-resistant properties under heavy loads and high rotating speeds.The present study demonstrates that the proposed g-C_(3)N_(4)/Ag hybrid is an excellent lubricating additive for polymer composites.

Study on the gas permeabilities in styrene-butadiene rubber by molecular dynamics simulation

In this research,molecular dynamics(MD)simulations were used to study the transport properties of small gas molecules in the butadiene-styrene copolymer(SBR).The condensed-phase optimized molecular potentials for atomistic simulation studies(COMPASS)force field was applied.The diffusion coefficients were obtained from MD(NVT ensemble)and the relationship between gas permeability;the chemical structure and free volume of butadiene-styrene copolymer were investigated.The results indicated that the diffusion coefficient of oxygen declined with increasing styrene content.The fraction of free volume(FFV)in butadiene-styrene copolymer was calculated.It was concluded that diffusion coefficient increased as the FFV increases,which is in accordance with the analysis of the small molecular hop through the free volume in polymer matrix.Subsequently,the glass transition temperatures of these copolymers were calculated by MD.The result showed that the glass transition temperature increased with increasing styrene content in polymer.

Simulation of Strip Rolling Using Elastoplastic Contact BEM With Friction

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.

Vibration monitoring for composite structures using buckypaper sensors arrayed by flexible printed circuit

Fiber-reinforced resin-based plastics are widely used in structural composites for aerospace and automotive applications,and they often face extreme load conditions in actual working environments.It is challenging to monitor the damage of the structure during the vibration process.This study was aimed at using buckypaper(BP)sensors to monitor the structural health status of composite structures under ambient vibrations.First,the feasibility of flexible printed circuit instead of wire is verified by the tensile experiment.Then the vibration monitoring experiment of the composite cantilever beam is carried out by using BP sensors systematically.The sweep frequency experiment determines the excitation frequency of the cantilever beam.Low-period vibration fatigue cycle and high-period vibration fatigue cycle experiments are designed to verify the vibration monitoring method using BP sensors.Besides,the signal response of BP sensors in the vibration experiment is analyzed,and the relationship betweenΔR/R0 and vibration acceleration is obtained.Finally,through the change law ofΔR/R0 of the sensor,the cumulative damage caused by vibration fatigue is visualized.It is demonstrated that the monitoring method based on BP sensors can be applied to study the damage behavior of composite structure under the vibration environment.