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Successful synthesis of glyconanoparticles has attracted much attention due to their various biointeractive capabilities, but it is still a challenge to understand different single-cell responses to exogenous particles among cell populations. Herein, we designed polyaniline-containing galactosylated gold nanoparticles (Au@PGlyco NPs) via in situ polymerization of ortho-nitrophenyl-β-galactoside assisted by Au nucleation. The nanogold-carrying polyaniline block produced electromagnetic enhancement in surface-enhanced Raman scattering (SERS). The underlying polymerization mechanism of ortho-nitrophenyl compounds via the formation of Au nanoparticles was investigated. Depending on how the galactoside moiety reacted with β-galactosidase derived from bacteria, the Au@PGlyco NPs-mediated SERS biosensor could detect low amounts of bacteria (∼1 × 102 CFU/mL). In addition, a high accumulation of Au@PGlyco NPs mediated the immune response of tumor-associated M2 macrophages to the immunogenic M1 macrophage transition, which was elicited by reactive oxygen levels biostimulation using single-cell SERS-combined fluorescence imaging. Our study suggested that Au@PGlyco NPs may serve as a biosensing platform with the labeling capacity on galactose-binding receptors expressed cell and immune regulation.

This paper is to study the mechanism of aging on the Rheological and Chemical Investigation of the bitumen and make correlations with the actual field behavior of the binder. The effects of ageing on rheological properties of asphalt has been studied by Bending Beam Rheometer(BBR). The objective of conducting these tests is to evaluate the performance of the bitumen in an aged and unaged states in relation to the effects of traffic speed and/or pavement temperature, traffic volume (number of load repetitions), and (thermal/load) cracking behavior.

This paper is to study the mechanism of aging on the rheological properties of the asphalt and make correlations with the actual field behavior of the binder. The effects of ageing on rheological properties of asphalt has been studied by Dynamic Shear Rheometer(DSR). Significant differences of rheological properties and composition were observed between fresh and aged asphalt. The results show that aging at low temperature increases the complex modulus of asphalt, but has little effect at high temperature.

Zirconia supported palladium catalysts were synthesized in the inert solvent by an in-situ reduction route. The preparative parameters, such as the reducing agents and the way of pre-nucleation, were regulated for the purpose of tuning the interaction between the support and the active metal (SMI). When a high dispersion of palladium is obtained by reducing agent of 1,2-hexadecanediol, a strong SMI between the active metal and zirconia is built up. This depresses the catalytic performance of the Pd/PdOx composite active phase for methane combustion. Conversely, the ratio of palladium species (Pd/PdOx) is apt to be optimized in the case of sample reduced by 2,5-di-tert-butyl-p-diphenol (DTBHQ). Furthermore, the catalysts involved a pre-nucleation step will result in a much weaker SMI, which leads to a decrease of catalytic activity for methane combustion. It is proved that an appropriate SMI is a key factor for the oxidation activity of supported palladium catalysts. The reduction of palladium component by 2,5-di-tert-butyl-p-diphenol (DTBHQ) launched until 200 °C. This would result in an active phase (Pd/PdOx) with less strong metal-support interaction (SMSI). Therefore, the ignition temperature of the methane oxidation is lowered by 100 °C.

Water-holding capacity (WHC) is an important indicator of pork quality, but the existing detection methods of WHC are either expensive or time-consuming. In this study, a new method of pork WHC detection was developed by a composite film. The preparation method, mechanical properties and service life of the composite film were studied. The result showed that composite film was 0.46 ± 0.06 mm thick and had a service life of 21 days, tensile strength of 7.72 ± 0.11 MPa and the elongation at break of 28.54 ± 0.15%. Thirty groups of pork samples were randomly selected to build the model and another twenty groups were used to verify the model accuracy. Results showed that the accuracy of composite film coupled with Fisher discriminant model to detect the WHC of pork is 90%. This study demonstrates the high value of composite film as a detection tool to classify WHC of pork.

Spin-exchange relaxation-free (SERF) co-magnetometer is considered to be a promising nuclear spin gyroscope due to its ultrahigh rotation measurement sensitivity and magnetic field disturbance cancellation ability. Recent experiments indicate that the relaxation of the noble-gas spins would result in reduction of the magnetic field disturbance cancellation ability, which means that magnetic noise from the passive magnetic shield in a SERF co-magnetometer can cause rotation rate measurement error. In this paper, the magnetic field frequency response of a SERF atomic magnetometer is derived based on state space method and the magnetic noise of different shield materials are measured. The magnetic noise error model in a SERF co-magnetometer is then derived and the magnetic noise induced rotation rate measurement error is quantitatively evaluated. The superiority of ferrite shield is shown by the performance of a K-Rb-21Ne co-magnetometer. Experimental results show that ferrite shield with lower magnetic noise and better temperature stability is a more favorable choice for the inner shield of the co-magnetometer.

Dense polycrystalline cubic boron nitride (PcBN) composites were fabricated by high-pressure and high-temperature (HPHT) sintering using polysilazane (PSN) and Al as sintering additive. After high-energy ball milling, the cBN fine particles were uniformly coated with PSN by ultrasonic treatment. After thermocuring and pyrolysis, the cBN–SiCN particles were mixed with Al. The PcBN composites were prepared after sintering at 1450 °C for 10 min with a pressure of 5 GPa. The refining effect of high-energy ball milling on the cBN particles was studied by scanning electron microscopy (SEM) and laser particle size analyzer. The oxidation of the cBN particles after milling was investigated by nitrogen–oxygen analyzer. The phase composition and microstructure of the sintered PcBN composites were investigated by X-ray diffractometer (XRD) and SEM. The main phases of the sintered PcBN composites are cBN, AlN, SiC and Si3N4. The conversion of cBN to hBN was inhibited by the formation of AlN. The mechanical properties of the sintered PcBN composites were improved by the appearance of SiC and Si3N4. The density and mechanical properties of the PcBN composites both increased with the content of the cBN particles increasing. The sintered sample with 60 wt% cBN, 30 wt% PSN and 10 wt% Al showed the best results: density of 99.7%, Vickers’ hardness of (25.2 ± 0.8) GPa and flexural strength of (602 ± 15) MPa.

To guide the design of 1–3 piezocomposite transducer with matching layer, a theoretical model was established using electromechanical equivalence principle and acoustics theory. The transmi...

A new severe plastic deformation for manufacturing thin-walled tube made of AZ31 magnesium alloy called TEB(Tube-Extrusion-Bending ) process, which combines direct extrusion with two step bending,has been developed to manufacture tube.The TEB process has been researched by using finite element modeling (FEM) method. The rules of extrusion temperatures and the extrusion forces varying with process parameters have been developed. A TEB process with installed containers and dies has been constructed to perform tests in order to validate the FEM model with different process conditions. And the microstructures evolution have been researched based on effective strains evolution. The results showed that refined and uniform microstructures can be achieved by TEB process. The research results showed that the TEB process would produce the serve plastic deformation and improve the recrystallization of the grains.The comparisons of FEM simulation and experimental results have been made to obtain the relative important principles of TEB process.

The aim of this study is to design and evaluate a simple free running Analog-Digital Converter (ADC) based on the Field Programmable Gate Array (FPGA) device to accomplish the energy and position readout of the silicon photomultiplier (SiPM) array for application as PET scanners. This simple FPGA-ADC based on a carry chain Time-Digital Converter (TDC) implemented on a Kintex-7 FPGA consists of only one off-chip resistor so it has greater advantages in improving system integration and reducing cost than commercial chips. In this paper, a FPGA-ADC based front-end electronics prototype is presented, and both the design principle and implementation considerations are discussed. Experiments were performed using an 8 x 8 (crystal size: 4 x 4 x 15 mm3 ) and a 12 x 12 (crystal size: 2.65 x2.65 x 15 mm3 ) segmented LYSO crystals coupled with an 8 x 8 SiPM (Jseries, from ON Semiconductor) array which is under 22Na point source excitation. Initial test results indicate that the energy resolution of the two detectors after correction is around 13.2% and 13.5 % at 511 keV, and the profiles of the flood histograms show a clear visualization of the discrete scintillator element. All measurements were carried out at room temperature (~25 degree), without additional cooling, 9 pages,14 figures

The spacer grid is widely used with the fuel rod buddle to stabilize the fuel assembly structure and reduce the vibration effect in the pressurized water reactor (PWR). To study the flow resistance characteristics of the working fluid under periodic fluctuation of the floating nuclear reactor (FNR), an experimental study of the pulsating flow resistance characteristics of a 5 × 5 fuel rod bundle (P/D = 1.326 and W/D = 1.268) was carried out. The ranges of the cycle-averaged Reynolds number Reta = 0.8 × 103–9 × 103, pulsating amplitude Au = 0.2–0.8 and dimensionless frequency ω ′ = 1.26–2.81 were covered in this experimental study. The experimental results indicated that the flow rate lags behind the pressure drop in the fuel rod bundle channel, and the phase lags increase with the increase of ω ′ but change slightly with Au and Reta. The instantaneous friction factor and local resistance coefficient are greater than the steady-state value at the end of deceleration and the whole acceleration stage in the pulsating flow cycle, and smaller than the steady-state value at the beginning of the deceleration stage. The present study compared the flow resistance of the accelerating and decelerating half-cycle with the steady-state value and found that the speed of the accelerating half-cycle increases gradually with the increase of Au, but the speed of the decelerating half-cycle flow resistance decreases gradually with the increase of Au. In addition, the obtained results have also indicated that the local resistance coefficient of the spacer grid is closer to the steady-state value than the friction factor in the accelerating and decelerating half-cycle. During the pulsating flow, the cycle-average friction factor and local resistance coefficient in the whole cycle are larger than the steady-state value under the corresponding Reynolds number. The normalization parameters of Cf = λ ta/λst and Csg = Kta/Kst are proposed to evaluate the effect of pulsating flow on the cycle-averaged flow resistance. Cf and Csg increase with the increase of Au and ω ′ , and decrease with the increase of Reta. In addition, it is found that Csg is smaller than Cf under the same pulsation parameters, which it means that the influence of fluid fluctuation on the resistance of the spacer grid is relatively small. Finally, the new correlations for predicting λta and Kta in the pulsating flow are established through dimensional analysis, and the prediction result is reasonably good.

The performance of the CFD prediction of the flow details in the fuel assembly using Reynolds-averaged Naiver-Stokes (RANS) model is still poor. Evaluation and understanding of the complicated turbulent flow structure in the rod bundle channel with mixing devices are essential to optimize turbulence models. Therefore, the current study used the time-resolved particle image velocimetry (TR-PIV) as the measurement tool and combined with the matching index refractive (MIR) technology to obtain high-fidelity experimental data in pressurized water reactor (PWR) based 5 × 5 rod bundle channel. Mean flow properties, turbulent parameters, and spectral analysis are presented in this paper. The results show that a large velocity gradient appears downstream of the spacer grid. The turbulence intensity has been decayed sharply about 45 mm (about 4.5Dh) downstream of the spacer grid, indicated that the mixing effect of the spacer grid becomes weakened after 4.5Dh. Besides, the fluctuating velocity and instantaneous swirl strength are utilized to present the transport characteristics of the eddies downstream of the spacer grid. Combined with the power spectral density spectrum analysis of the transverse fluctuating velocity, the vortex shedding frequency of the mixing layer downstream of the spacer grid is obtained. These results indicate the existence of the quasi-periodic oscillations in the rod bundle channel. Finally, the integral scale on the rod bundle channel is calculated using the cross-correlation function of two reference points. This result reveals that the turbulence in the rod bundle channel is anisotropic.

AZ91D magnesium alloy matrix composites reinforced with nano SiC particles (n-SiCp) was fabricated by Friction Stir Processing, and the effects of n-SiCp on the β-Mg17Al12 phase precipitation at 180 °C as well as the age hardening response of AZ91D were investigated by X-ray diffraction, optical microscopy, scanning electron microscopy, transmission electron microscopy, and micro Vickers hardness measurements. The results show that, with the addition of n-SiCp, the microstructure of AZ91D after FSP was greatly refined, the texture strength was decreased, and the age hardening efficiency became inferior. As n-SiCp can efficiently block the migration of grain boundaries and grain growth, the composite exhibited a higher microstructure stability at elevated temperatures, and the discontinuous precipitation of β-Mg17Al12 phase that dominated the age process of AZ91D at 180 °C was remarkably restricted in the composite. Besides, n-SiCp promoted the continuous precipitation of β-Mg17Al12 phase and the precipitation rate in the composite was faster at the initial aging stage, but on further aging the precipitation rate became gradually slower than that in the AZ91D. The underlying mechanisms for the different age precipitation behavior and age hardening response were also discussed.

Graphene oxide (GO) coated fiber via deposition of GO sheets on polyvinyl alcohol (PVA) fiber containing silver nanowires (AgNWs) was fabricated, and chemical reduction for GO on the fiber surface was carried out to obtain reduced GO (rGO) coated PVA-AgNWs (rGO/PVA-AgNWs) fiber. The results showed that the rGO sheets were closely adhered on the surface of fiber, the electrical conductivity of the fiber increased with coating times of GO, and the conductivity was high up to 2.05×10-3 S/m when GO was coated 3 times on the fiber and reduced. The synergistic effect of rGO and AgNWs for the conductivity was also clearly indicated.

Lean-premixed combustion technology has been adopted widely for heavy-duty gas turbine application. The multiple-swirl structure might shorten the flame brush length and reduce emissions. However, ...

In possible accident scenarios of the reactor coolant system, the convection and mixing characteristics of borated water have a great influence on reactivity variations in the reactor, and then impact the reactor safety. The mixing and diffusion characteristics of the boric acid solution in the annular downcomer is studied by laser-induced fluorescence (LIF). An aqueous solution of Rhodamine B (RhB) fluorescence dye, which is used to simulate boron solution, was injected in the coolant inlet to visualize the fluid mixing process in the annular volume. Laser sheet was formed by optical system to emit the fluorescence, a high-speed camera was used to capture the fluorescence information for reconstructing the concentration distribution of dye. In order to guarantee the experimental accuracy, LIF image processing and a calibration technology are applied. The concentration profiles were implemented to illuminate the fluid mixing between dye solution and diluted water in the downcomer. The coefficient of variation (COV) was conducted to quantify the spatial and temporal transport of dye in the annular downcomer. The results indicate that a higher flow improves the transport ability of dye in the transverse direction, and shortens the distance and time to uniform. The mass force can accelerate the dye transport in the vertical direction. The whole-field measurement technique implemented in this study is expected to provide an insight in the research of flow mixing in the complex geometry. The experimental results can provide a better understanding of mixing phenomena in annular downcomer, and it is also useful for the annular downcomer CFD validation.

Transmission electron microscopy (TEM) is being pushed to new capabilities which enable studies on systems that were previously out of reach. Among recent innovations, TEM through liquid cells (LC-TEM) enables in operando observation of biological phenomena. This work applies LC-TEM to the study of biological components as they interact on an abiotic surface. Specifically, analytes or target molecules like neuropeptide Y (NPY) are observed in operando on functional graphene field-effect transistor (GFET) biosensors. Biological recognition elements (BREs) identified using biopanning with affinity to NPY are used to functionalize graphene to obtain selectivity. On working devices capable of achieving picomolar responsivity to neuropeptide Y, LC-TEM reveals translational motion, stochastic positional fluctuations due to constrained Brownian motion, and rotational dynamics of captured analyte. Coupling these observations with the electrical responses of the GFET biosensors in response to analyte capture and/or release will potentially enable new insights leading to more advanced and capable biosensor designs.

The magnitude and direction of geo-stress undergoes complex changes following disturbance by artificial excavation in underground engineering. Tests were conducted using the self-made multi-functional true triaxial geophysical apparatus to investigate the influence of stress Lode angle on deformation, deformation modulus, and permeability of sandstone under true triaxial stress conditions (σ1> σ2 > σ3). The results indicate that principal, volumetric, and deviatoric strains, as well as permeability varied with the stress Lode angle, and eventually increased/decreased at different levels. For constant deviatoric stress and variable mean stress, the plastic strain decreased with increasing M (ratio of deviatoric stress q to mean stress p), whereas the permeability increased. For constant mean stress and variable deviatoric stress, the principal, volumetric, and deviatoric strains, as well as the permeability decreased first and then increased with the increase in M; the rock generated fracture surface when M was relatively large. The gas flow and stress axis directions significantly influence the value and changing trend of the permeability. With increasing stress Lode angle, the permeability increased first and then decreased. In our stress condition testing, the permeability value and variation range were maximum when the gas flow direction was parallel to σ1; when it was parallel to σ3, the permeability demonstrated an upward trend, but with a smaller increase range. Conversely, when it was parallel to σ2, the permeability decreased and the variation range was minimized. Finally, based on the analysis of the experimental results, we developed a permeability model that is expressed by both volumetric and deviatoric strains.

Vacuum circuit breaker (VCB) has a longer life and shorter opening time than SF(6) circuit breaker, but current single-break VCB cannot be applied in high-voltage power system directly. Here, a fast 363 kV multi-break VCB design is presented and its voltage distribution characteristic and stray capacitors are analysed. A three-dimensional finite-element model of modularised hexa-break VCB composed of 12 vacuum interrupter modules installed on three series connected platforms is developed to calculate the voltage distribution and distributed capacitances. The result shows that the voltage distribution is uneven, and the first break shares the 67.974% of the whole applied voltage. On account of distributed capacitances parameters, an equivalent capacitance model with PSCAD is built to discuss the voltage distribution characteristic at different grading capacitance values, and the optimal grading capacitance value is determined to 10 nF.

The flow behavior and the flow structures inside the fuel assembly are a critical issue in the thermal-hydraulic analysis of a nuclear reactor. A better understanding of the fluid dynamics in the rod bundles can enhance the geometry design of the fuel assembly to improve the safety and efficiency of the reactor. The aim of this work is to investigate fluid mixing in a rod bundle experimentally with flow visualized and whole-field measurement techniques. In this paper, laser induced fluorescence (LIF) technique is adopted, and a visual experiment facility has been designed to achieve a concentration measurement in the both transverse and longitudinal sections. Matching index of refraction (MIR) technique and a new calibration method are applied to guarantee the experimental accuracy. Based on the above technology, concentration distribution in the rod bundle is obtained at the Reynolds number of 10450. A comparison of concentration distribution in the bare rod bundle and the rod bundle with spacer grids is performed to assess the mixing performance of the spacer grid. In the longitudinal measurement, the characteristics of fluid mixing downstream the spacer grid are analyzed, and the effect of different resistance components on the spacer grid for concentration distribution is revealed. The movement and position of dye in the transverse sections are obtained, the movement characteristics of dye are also analyzed. Furthermore, the coefficient of variation (COV) is used to quantify the fluid mixing in the rod bundle. The experimental results benefit the design of fuel assembly, and the data acquired in this study can be used as benchmark data for validating CFD codes.

The objective of this work was to investigate phytantriol-based liquid crystal (LC) gels including cubic (Q2) and hexagonal (H2) phase for ocular delivery of pilocarpine nitrate (PN) to treat glaucoma. The gels were produced by a vortex method and confirmed by crossed polarized light microscopy, small-angle X-ray scattering, and rheological measurements. Moreover, the release behaviors and permeation results of PN from the gels were estimated using in vitro studies. Finally, the anti-glaucoma effect of LC gels was evaluated by in vivo animal experiments. The inner structure of the gels was Pn3m-type Q2 and H2 phase, and both of them showed pseudoplastic fluid properties based on characterization techniques. In vitro release profiles suggested that PN could be sustainably released from LC gels within 48 h. Compared with eye drops, Q2 and H2 gel produces a 5.25-fold and 6.23-fold increase in the Papp value (p

With the increase in the voltage and capacitance of gas-insulated transmission lines (GILs), the insulation failure of GIL has attracted more and more attention. Further understanding of the partial discharge (PD) and flashover characteristics of metal particles on the insulator surface, as well as the flashover mechanism, is necessary to reduce the failure rate and improve the reliability of the equipment. In this study, an ultra-high voltage (UHV) AC insulator PD test and measurement system based on the cross-reference pulse current (PC) and ultra-high frequency (UHF) methods were established. The PD development and flashover characteristics of 5 mm-long metal particles at different positions on the surface of a UHV AC insulator, as well as the surface charge accumulation, were studied. The results show that the discharge of millimetre-scale metal particles on the insulator surface under PD test conditions is relatively low (generally lower than 2PC), and it is difficult to be detected by the conventional PC and UHF methods due to their insufficient sensitivity. Moreover, it is found that the weak PDs of the millimetre-scale metal particles will result in a charge accumulation on the insulator surface under AC voltage, which eventually will lead to the insulator flashover. The PDs of the UHV AC insulator before flashover are generally small, which will make it difficult for online monitoring systems to give an effective alarm before flashover.

An iron oxide (Fe3O4)-mediated photothermal treatment has been revealed as the next generation of noninvasive and nontoxic theranostic nanoagents compared with other inorganic nanoparticles. Nevertheless, iron oxide with NIR-mediated activity is limited by its inability to be mass produced and its long-lasting photon-to-thermal conversion. Herein, we develop using a green reagent, tannic acid (TNA), which assisted hydrothermal reaction to generate black Fe3O4 nanoparticles by using commercially available nanoptical γ-Fe2O3 NPs as a starting material. The phase transformation from γ-Fe2O3 to the reduced form of Fe3O4 is assisted by TNA in the solution phase. Based on the formation of the interfacial TNA-Fe chelation and the delicate phase transformation from γ-Fe2O3 to Fe3O4 structures, the colloidal black Fe3O4 nanoparticles exhibit broad absorption that covers the visible and NIR wavelengths. Specific interfacial ligand-to-metal charge transfers between the TNA and iron ions at the surface of iron oxide nanoparticles, improves the absorbance and leads to the highest photon-to-thermal conversion (η = 35.7%) at 808 nm compared with other iron oxide nanomaterials. After modifying d-mannose (MA) onto the surface of the Fe3O4@TNA nanoparticles, the local heat can efficiently transfer from the Fe3O4@TNA nanoparticles to the vicinity of the bacterial FimH adhesion molecule, causing extensive photothermal injury to O157:H7 and ESBL strain bacteria with over 99% cell death at 200 ppm[Fe] with 808 nm light at 2.25 mW/cm2. Based on its robust photostability, Fe3O4@TNA@MA shows photothermal bactericidal recyclability through magnetic collection, adhesion, and photothermal processes.

A three-dimensional (3D) flower-shaped Li4Ti5O12-graphene (Gr) hybrid micro/nanostructures and pine needles derived carbon nanopores (PNDCN) has been prepared by using the effective hydrothermal process. Due to the unique micro/nanostructures which can provide abundant surface active sites, the obtained 3D Li4Ti5O12-Gr displays a high specific capacitance of 706.52 F g−1 at 1 A g−1. The prepared PNDCN also exhibits high specific capacitance of 314.50 F g−1 at 1 A g−1 benefiting from its interconnected honeycomb-like hierarchical and open structure, which facilitates the diffusion and reaction of electrolyte ions and enables an isotropic charging/discharging process. An asymmetric supercapacitor utilizing Li4Ti5O12-Gr as positive electrode and PNDCN as negative electrode has been fabricated, it delivers a high energy density of 35.06 Wh kg−1 at power density of 800.08 W kg−1 and outstanding cycling stability with 90.18% capacitance retention after 2000 cycles. The fabrication process presented in this work is facile, cost-effective, and environmentally benign, offering a feasible solution for manufacturing next-generation high-performance energy storage devices.

Enormous research efforts have been made in the field of design and fabrication of material structure of supercapacitors because of the high complexity in obtaining both high energy and power density. Herein, a hierarchical structure of a Co3O4@ biomass-derived carbon fiber @Co3O4 (@BCF@), which consists of hollow porous carbon fiber as the sandwich layer and Co3O4 particles both as an internal shell and an external cladding layer, has been designed and fabricated. Excellent electrochemical performances have been observed for @BCF@ supercapacitors, i.e., high specific capacitance (892 F g−1 at a current density of 0.5 A g−1) and long-term cycling stability (retained 88% even after 6000 cycles). Furthermore, they also exhibit potential application values in asymmetric supercapacitors. The selected biomass-derived hollow carbon fiber with porous structure not only provides an ideal electron transfer path to overcome the limitation of high resistance of most oxide electrodes but also serves as a backbone of inner wall space, which could load more Co3O4 particles per unit electrode area to maximize the redox reaction. Therefore, @BCF@ with sandwich structure is a promising candidate as an electrode material for the development of energy storage devices in the near future.

In this work, a novel strategy is developed to solve the issue of mutually exclusive high mechanical robustness and thermo-stability for thermoplastic polyurethane (PU). A leaf-like and reticulate interfingering superstructure can be seen. The superstructure of polyurethanes can also be tuned by the polarity of chain extender molecular via changing the number for ferrocene redox centres, thus to further enhance the thermal stability and elasticity of PUs. As a result, by incorporating bisferrocene units into the main chain of PU, a high-performance PU elastomer can be synthesized with a highest initial degradation temperature of T5% of 345 °C, a highest tensile strength of 42.3 MPa with an elongation over 1000%, as well as a toughness of 19.6 GJ m−3. These results conclusively suggest that high-performance thermoplastic polyurethane elastomers had great promise for potential application in a wide range of practical fields.

In this study, 20 mm thick AA7075-T6 alloy plates were joined by friction stir welding. The microstructure and mechanical properties of the nugget zone along the thickness direction from the top to the bottom was investigated. The results showed that the microstructure including the grain size, the degree of dynamic recrystallization, the misorientation angle distribution and the precipitation phase containing its size, type and content exhibited a gradient distribution along the thickness direction. The testing results of mechanical properties of the slices showed that the nugget was gradually weakened along the depth from the top to the bottom. The maximum ultimate tensile strength, yield strength and elongation of the slice in the nugget top-middle are obtained, which are 415 MPa, 255 MPa and 8.1%, respectively.

As promising electrode materials in supercapacitor, metal oxides have attracted significant attention recently. At present, it is highly desirable but remains challenging to prepare three-dimensional (3D) metal oxides hollow materials for further improving the performance of supercapacitors. Herein, 3D chestnut shell-like Li4Ti5O12 hollow sphere is successfully fabricated by using an effective hydrothermal strategy. Owing to the unique structural feature and the desirable chemical composition, Li4Ti5O12 hollow sphere displays a remarkable capacitance of 653.22 F/g at 1 A/g and keeps 88.56% over 4000 cycle. Furthermore, one aqueous asymmetric supercapacitor (ASC) is constructed based on Li4Ti5O12 and N-doped graphene oxide (NGO) which is synthesized by a facile burning method. The Li4Ti5O12//NGO ASC shows an energy density of 26.15 Wh/kg at power density of 799.83 W/kg, and yet keeps 14.45 Wh/kg even at 8.01 kW/kg. This strategy may offer a versatile idea of tailoring new type of 3D metal oxides hollow materials and opens the possibility for using in high energy storage device.

Various V2O5 three-dimensional nanostructures are synthesized using a facile template-free hydrothermal method and evaluated for use as supercapacitor electrode materials. As a result, the yolk–shell structure assembled from ultrathin nanosheets shows the best electrochemical performance, with a specific capacitance of 704.17 F g−1 at 1.0 A g−1 and a high capacity retention of 89% over 4000 cycles at 3.0 A g−1. In addition, a continuous three-dimensional porous coralline-shaped carbon is synthesized from osmanthus and has a large Brunauer–Emmett–Teller surface area of 2840.88 m2 g−1. Then, an asymmetric supercapacitor is developed using the as-prepared yolk–shell V2O5 as a positive electrode and the osmanthus derived coralline-shaped carbon as a negative electrode. This exhibits an energy density of 29.49 W h kg−1 at a power density of 800 W kg−1 with a good cycling performance that retains 90.6% of its initial capacity after 2000 cycles at 3.0 A g−1. Furthermore, two cells in series can easily brightly light up a light-emitting diode (3 V), further demonstrating the great potential of the prepared materials for high-performance supercapacitor devices.

A facile method for the large-scale production of 4MoO3·2NH3·H2O (MAH) nanocrystal with tunable size and morphology is developed through an antisolvent crystallization approach. The introduction of hydroxyl groups during crystallization promotes the formation of oxygen vacancies on the MAH. Due to the high concentration of Mo5+ centres, small nanosheet thickness, and sandwich-like crystal structure, MAH-20 exhibits an outstanding adsorption capability toward cationic dyes, with the maximum adsorption capacities up to 1169.2 mg·g−1 for methylene blue (MB) and 1452.8 mg·g−1 for rhodamine B (RhB), which are almost 10 times as that of MAH-0. An electrostatic adsorption mechanism is proposed to interpret the highly selective adsorption activity toward cationic dyes. Moreover, a fast and recyclable treatment and adsorbent regeneration are realized based on a continuous flow filtration device.

By using scanning electron microscopy (SEM) equipped with electron back-scattered diffraction (EBSD) system, transmission electron microscopy (TEM) and CorrTest4 electrochemical workstation, effects of chromium content (1.35wt% – 3.95 wt%) on the mechanical properties and anti-corrosion behaviours of high manganese Fe-Mn-C-Al-Cr-N twinning-induced plasticity (TWIP) steels were studied. The results show that Cr content has an obvious influence on the mechanical properties and fracture behaviors of the high manganese TWIP steels. The yield and ultimate tensile strengths of the steel sheets were improved with increasing Cr content while the elongation was reduced. In addition, with the increase of Cr content, the fracture mode changed from ductile fracture pattern with coarse dimples and tear ridges (Cr content ≤ 2.35%) to intergranular fracture (when Cr content is 3.95%). Furthermore, Cr content has a tremendous effect on anti-corrosion behaviors of the high manganese TWIP steels. The increase of Cr content enhanced the corrosion resistance of the annealed steel sheets by improving the proportion of low-angle boundary.

Laser engraving, which is a high-precision and non-contact processing technology, has been widely used to process the difficult-to-cut mould steel. However, the efficiency is still low and the influence of laser engraving on the microstructure and properties of engraved surface also needs further study. By varying the assist gas (Argon, Compressed air, and Oxygen) of nanosecond laser engraving of Cr12MoV mould steel, the material removal rate and surface quality were compared, and the mechanisms of elemental diffusion and microstructural evolution in surface remelting layer were investigated to understand the variation in micro-hardness values. The results showed that the exothermal chemical reactions significantly increased the efficiency of laser engraving, but the surface quality was deteriorated and the detachment of elements C and Cr in remelting layer was promoted. Thus, lower hardness was observed for the remelted layer in the presence of oxygen or compressed air compared to Argon, although the micro-hardness of remelted layers was all increased attributed to grain refinements. Results suggested that the use of oxygen gas during rough engraving increased the material removal rate and reduced the cost, and the use of Argon gas at final engraving steps improved the quality and mechanical properties of the engraved surface.

In this research, the numerical simulation and analysis of flow behavior in 5 × 5 fuel rod bundle with consideration of spacer grid has been conducted. ANSYS FLUENT 19.0 with the consideration of the transition SST (Shear-Stress Transport) with SAS (Scale-Adaptive Simulation) turbulence model is used for the numerical simulation. The obtained simulation results are reasonable compared with the experimental data based on the comparison in the aspect of velocity distribution. The effect of the spacer grid on the flow behavior in the fuel rod bundle has also been investigated. The mixing vanes in the spacer grid can cause various strong flow branches; these flow branches develop and cause the complex flow behavior in the fuel rod bundle. Additionally, the secondary flow, the swirling factor and the mixing factor were investigated for the quantitative analysis of the spacer grid effect on the flow mixing behavior in fuel rod bundle.

The bulk TC17 was subjected to the high energy shot peening (HESP) at the air pressures ranging from 0.35 to 0.55 MPa and processing durations ranging from 15 to 60 min. The microhardness (HV 0.02 ) from topmost surface to matrix of the HESP processed TC17 was measured, which generally decreases with the increase of depth from topmost surface to matrix and presents different variation with air pressure and processing duration at different depths. A fuzzy neural network (FNN) model was established to predict the surface layer microhardness of the HESP processed TC17, where the maximum and average difference between the measured and the predicted microhardness were respectively 8.5% and 3.2%. Applying the FNN model, the effects of the air pressure and processing duration on the microhardness at different depths were analyzed, revealing the significant interaction between the refined layer shelling and the continuous grain refinement.

An electrochemical model for a molten sodium hydroxide direct carbon fuel cell (MHDCFC) is developed based on electrochemical reaction dynamics, mass transfer, and electrode processes in the cell. Activated carbon and graphite are considered the main fuels, and static and dynamic parameters describing polarizations are taken into account for valuation and optimization of cell performance. Asymmetric reaction compartments are used in the MHDCFC, and the effect of the anodic compartment height on polarization is described first. The cell performance mainly depends on temperature ( T ), the pressures in the anodic ( P an ) and cathodic compartments ( P cat ), the anodic compartment height ( H 1), and the fuel type. Besides, cell performance is affected by ohmic polarization, anode activation polarization, cathode concentration polarization, and cathode activation polarization, in order of precedence. At P an of 1.8 atm, P cat of 1.7 atm, H 1 of 0.06 m, and T of 773–973 K, the efficiencies (e) of the cells with activated carbon and graphite are higher than 50% at current densities of 0–500 A m −2 and 0–700 A m −2 , respectively. The maximum power densities (e > 50%) are achieved for activated carbon and graphite and reach 367.6626 W m −2 and 498.9687 W m −2 , respectively.

In this paper, the effects of variable parameters on the average Nusselt and Sherwood numbers between moist air and liquid water film in vertical plate channels are investigated using an approach proposed by previous work. The validity of data is also investigated. Traditional correlations for the average Nusselt and Sherwood numbers are not comprehensive enough as they cannot indicate the effects of inlet parameters on heat and mass transfer process. In this research, correlations for the average Nusselt and Sherwood numbers are developed in terms of moist air inlet Reynolds number, ratio of water to moist air inlet mass flow rate, ratio of channel length to half channel width and moist air inlet dimensionless temperature. The definition of the moist air inlet dimensionless temperature takes into account the effects of moist air inlet dry-bulb and wet-bulb temperatures and water film inlet temperature. The correlations show that the moist air inlet dimensionless temperature has the greatest influence on the average Nusselt number compared with that of the other dimensionless parameters, but it has the lowest influence on the average Sherwood number. The results would be helpful to understand the heat and mass transfer behavior between moist air and liquid water film.

Doping is an efficient method to promote the electronic conductivity and improve the capacitive performance of electrodes for further energy conversion. Herein, by doping heteroelement metal ions, an ultrathin Y (yttrium)-doped α-Ni(OH)2 nanosheet electrode with a large surface area and hierarchical porous structure is fabricated via a facile approach. The Y-doped α-Ni(OH)2 nanosheets exhibit a high specific capacitance of 1860 F g−1 at a current density of 1 A g−1 mainly due to the increased electronic conductivity of the increased Ni3+ species, as evidenced by density functional theory calculations. As a result, the asymmetric supercapacitor device based on the Y-doped α-Ni(OH)2 nanosheet electrode demonstrates both a remarkably high energy density (58.4 W h kg−1) and power density (754.56 W kg−1).

Muti-wall carbon nanotubes (MWCNTs) were functionalized by grafting polyimide (PI) on their surface via Friedel-Crafts acylation. The functionalized MWCNTs (f-MWCNTs) showd less damages than unfunctionalized ones. The partially imidized polyamide acid as-spun fibers containing f-MWCNTs were prepared by wet spinning, and the final PI/f-MWCNTs composite fibers were obtained by heat treatment. The tensile strength of the PI based composite fiber containing 1.0 wt% f-MWCNTs was 818.3 MPa and the Young’s modulus was 9.26 GPa, which were about 81% and 88% higher than those of pure PI fiber, respectively. Besides, the thermal stability of PI/f-MWCNTs composite fibers was obviously improved.

Traditional coal-fired-plants release large amounts of pollutants and have low efficiency. A molten hydroxide direct carbon fuel cell (MHDCFC) that directly converts the chemical energy into electricity with pure CO2 product is a potential clean power in the future. Low temperature and clean scaled-up operations are challenges for a MHDCFC. In this study, temperature, active specific surface area, fuel mass, and fuel type are studied through a model because they may significantly influence the cell performance by polarizations. When the active specific surface areas of graphite, activated carbon, and carbon black are 100 m2/m3, 1500 m2/m3, and 1500 m2/m3, respectively, the differences between the highest power density and other two power densities of the MHDCFCs powered by the three fuels reduce with decreasing temperature. Low temperature increases polarizations. The ratio of activation polarization to ohmic polarization is greater than 1/2 when the active specific surface area decreases to 100 m2/m3 at 623 K. A continuous increase in active specific surface area to 700 m2/m3 may cause decreases in amounts of activation polarization and toxic chemicals used in fuel processing, simultaneously. Large fuel mass and weak conductivity of a fuel weaken the cell performance by increasing ohmic polarization at low temperatures. The MHDCFC is governed by activation and ohmic polarizations. The model may balance an increase in polarizations, an increase in invalid CO2 and a decrease in volatile amount of corrosive electrolyte at low temperatures and scaled-up levels for a clean and efficient electricity generation.