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Ammonium bisulfate (ABS) is a viscous compound produced by the escape NH3 in the NO reduction process and SO3 in the flue gas at a certain temperature, which can cause the ash corrosion of the air preheater in coal-fired power plants. Therefore, it is essential to study the formation temperature of ABS to prevent the deposition of ABS in air preheaters. In this paper, the SO3 reaction kinetic model is used to analyze the SO3 generation process from coal combustion to the SCR exit stage, and the kinetic model of NO reduction is used to analyze the NH3 escape process. A prediction model for calculating the ABS formation temperature based on the S content in coal and NO reduction parameters of the selective catalytic reduction(SCR) is proposed, solving the difficulty of measuring SO3 concentration and NH3 concentration in the previous calculation equation of ABS formation temperature. And the reliability of the model is verified by the actual data of the power plant. Then the influence of S content in coal, NH3/ NOx molar ratio, different NOx concentrations at SCR inlet, and NO removal efficiency on the formation temperature of ABS are analyzed.

The conversion of CO2 into high value-added chemical products is the focus of current scientific research. We make use of the specific porous structure of nanosized metal-organic frameworks (MOFs) loading the highly active yet metastable nano Cu2O to catalyze the conversion of CO2 into a series of high value-added bioactive pyridone/pyrone-3-carboxylic acid products via heterocyclic 4-hydroxy-2-pyridones/pyrones, which exhibit high activity, selectivity, and reusability. Nano MOF sponge-covered metastable nanoparticles (NPs) converting CO2 into high value-added bioproducts provide a facile "dual-side surfactant" strategy, a highly efficient composite catalyst, and a practicable pathway not only for the sustainable use of CO2 but also for environment-friendly production of bioproducts.

The spray behavior of a twin-fluid nozzle (TFN) can seriously affect lubrication performance, cutting fluid consumption and tool life during the manufacturing process. It is important to study the spray behavior and droplet size distribution characteristics of twin-fluid atomization to improve machining performance and reduce environmental pollution. In the current study, first, via a phase Doppler method, the spatial distribution of spray behavior of a TFN with and without a self-excited vibrating cavity (SVC) is analyzed and compared. Then, under various gas-to-liquid mass ratio values, the counts percent and cumulative distributions of droplets of a TFN with different SVC structures are further investigated. In addition, comparative investigations of the effects of different TFNs on the lubrication performance are conducted. The results show that the SVC structural parameter and gas-to-liquid mass ratio have an important influence on the secondary atomization of a TFN with an SVC, which significantly affects the spray behavior and droplet size distribution characteristics. The velocity differences between the gas-liquid two phases and the strong turbulence around the SVC are the key factors affecting the secondary atomization. The SVC can significantly increase the spatial coverage of droplets and improve the droplet spatial distribution characteristics of diameter and number concentration. The TFN with an improved SVC has better spray behavior and droplet size distribution characteristics, resulting in reductions in tool wear, cutting temperature and surface roughness of approximately 24.84 %, 21.24 % and 31.86 %, respectively, compared with the TFN without an SVC.

The droplet dynamic behavior of spraying during the manufacturing process affects tool life, cooling, and lubrication. A detailed understanding of droplet dynamic behavior is required to improve the surface quality while reducing the cutting fluid consumption. In this study, quantitative measurements for droplet diameter, number concentration, and axial velocity were carried out through a phase Doppler particle analyzer technique. The droplet characteristic spatial distributions of a standard twin-fluid nozzle (STN) and a novel twin-fluid nozzle (NTN) under different gas-to-liquid mass ratio (GLR) values were analyzed in detail. The results showed that the high-speed internal gas flow of an atomizing core has a significant effect on improving the synergistically enhanced atomization behavior, and more smaller droplets and an increased droplet momentum are easily obtained. Furthermore, a better spatial distribution of atomization characteristics can be achieved under a higher GLR of 4.3%. Furthermore, the effects of the novel atomizing core structural parameters on the droplet mean velocity spatial distribution, droplet turbulence, and root mean square velocity fluctuation were investigated. The results also showed that the improved NTN can effectively improve the spray atomization performance and droplet dynamic characteristics. In addition, comparative studies of the effect of the atomizing core structure on the machining performance were performed. Compared with the STN, the improved NTN achieves a significant reduction in cutting temperature, tool wear, and surface roughness of 17.25%, 33.96%, and 37.83%, respectively, owing to the better droplet dynamic characteristics and spatial distribution of spray atomization characteristics.

The effect of the particle size (50–325 mesh) and content (0–0.1 wt%) of metallic aluminum powder on the explosive spalling resistance of corundum-based refractory castables were investigated in this study based on air permeability, pore size distribution, heat release, fracture energy and microstructural analyses. The experimental results show that the addition of Al powder significantly improves their explosive spalling resistance. As observed, the explosive spalling resistance of the castables was mainly influenced by the permeability mechanism and the fracture energy. Permeable paths were generated in the microstructure of the sample during the overlapping period between the curing process and the H2 gas forming one, derived from the Al–H2O reaction. The highest permeability level was obtained when 0.075 wt % of Al powder with size of 100 mesh was incorporated into the corundum-based refractory castables. At the same time, the fracture energy of the castable samples was increased accordingly.

In this work, manganese was combined with ZIF-67 to form a multi-shell structure, and then the core-shell structure of Co3O4/MnCo2O4.5 as an electrode material was obtained by optimizing the thermal treatment, which perfectly inherited the rhombic dodecahedral shape of the ZIF-67 templates. Benefiting from the composition of core-shell structure and the synergistic effect of bimetallic manganese-cobalt oxides on shell surface, the Co3O4/MnCo2O4.5 reached a specific capacity of 636 F g−1 at a current density of 1 A g−1. Owing to a cycle life of 86% after 5000 charge and discharge cycles, its electrochemical performance had been improved significantly, compared with the Co3O4 acquired by pure ZIF-67 at a specific capacity of 320 F g−1 and a cycle life 79.9%. All of this confirmed the Co3O4/MnCo2O4.5 was an excellent electrode material for the pseudopotential capacitor.

Xtacking™ is a novel 3D (three-dimensional) NAND flash architecture, in which memory cells and peripheral circuits are bonded by millions of pairs of small-pitch metal vias. Consequently, its bonding interface reliability attracts great interest. In this paper, we conducted reliability test of Xtacking™ bonding interface in both test structure level and product level. In test structure level reliability test, the bonding layer showed stable electrical properties and bonding interface after ultra-long time thermal or humidity stress (e.g., 7000hrs), which is much longer than common industry requirement (e.g., 1000hrs). Furthermore, the double cantilever beam test following long time temperature cycling and package level electromigration test also demonstrated good strength and stability of bonding interface. In product level reliability test, no function failure or scanning acoustic microscope image abnormality was observed after thermal or humidity stress, which further proves the excellent reliability of the bonding interface in actual product. Thus Xtacking ™ architecture achieved robust and reliable bonding interface with millions of pairs of small-pitch metal vias.

Microstructures determine flow properties of microfluidic chip. Micromold forming is an effective method to realize mass manufacturing of microfluidic chips. This requires to machine some kind of special microstructure of high surface quality on a metal/alloy workpiece. Micro V-shaped grooves are the typical microstructures of the chip micromolds used for controlling microfluid or weld packaging. In this research, a scanning micro-electrochemical machining (ECM) process of V-shaped grooves is proposed using a tool electrode fabricated by micro–electrical discharge machining (EDM) on-machine. Theoretical and experimental research was conducted for achieving the V-shaped grooves with a given angle on die steel. A long-distance V-shaped groove with the given angle of 67 deg and the depth of 125 μm was successfully machined.

In order to reduce the thickness of recast layer and improve the surface quality of film cooling holes, a novel high speed self-adjusting electrical discharge machining (EDM)/ electrochemical machining (ECM) approach was developed by applying two independent flushing systems that were able to switch automatically in the machining process. The new flushing systems used different work-liquids and online dynamically changing discharge parameters. With the change in gap distance and the depth of the hole drilled, the dominant machining mechanism is graduated changed from EDM to electrochemical discharge machining (ECDM) and ECM. The formation mechanism of the recast layer on nickel alloy was investigated by comparing the surface characters of the bulk material and those of the recast layer using transmission electron microscope (TEM) and energy dispersive X-ray spectroscopy (EDS). The results from comparison experiments, in which different discharge parameters and sustaining time were applied, show that this new flushing systems would ensure much better flushing continuity of the working fluid and improve the discharge gap status. In addition, low voltage and current would benefit the ECM process and the removal of recast layer.

Condensing boilers are efficient for the utilization of natural gas. However, condensed droplets in flue gas are supercooled after condensation heat transfer, and direct contact devices cannot accurately measure the temperature of flue gas containing such droplets. Therefore, an in situ heating interlayer pumping device was designed. Experimental results showed that in situ heating interlayer pumping device can effectively filtered out the influence of supercooled droplets, the temperature of flue gas measured by the proposed device was about 3 °C higher than that measured by direct contact temperature measuring device; the device optimum flow rate was 0.35 L/min, optimum heat tracing temperature was in the range 100–140 °C; the effective reliability of the device was verified experimentally using the positive balance efficiency and the counter balance efficiency of 30-kW gas-fired condensing heat-transfer test platform.

p-tert-Butylcalix[4]arene-derived cyanate ester resins, both single and binary systems, were synthesized and studied for their thermal properties. The results showed that pure calixarene cyanate ester can be thermally cured at comparatively high temperature, which remains in original powder state after thermally cured. So the pure calixarene cyanate ester resin fails to meet the processing demands of resin-matrixed composite. In this work, p-tert-butylcalix[4]arene cyanate ester was chemically functionalized to have highly decreased thermal cure temperature (by copolymerization with epoxy, bisphenol A cyanate ester (BPACE), and polysilazane (PSZ), respectively). The binary resins were thermally cured into monolithic materials. The optimal acceleration of thermal cure reaction was achieved with an addition of 10% PSZ. The addition of epoxy resin decreased thermal resistance and carbon yield of p-tert-butylcalix[4]arene cyanate ester and addition of BPACE slightly decreased thermal resistance and carbon yield, while PSZ highly improved thermal resistance and carbon yield. Glass transition temperature of the co-cured resin of calixarene cyanate ester with 10% PSZ was much higher than that of conventional BPACE. Calixarene cyanate ester possesses much better property than that of conventional BPACE resin.

In this study, boron-doped polycrystalline diamond (BDD) films were deposited on 6-inch silicon wafer by using microwave plasma chemical vapor deposition (MPCVD). Mixed gas containing hydrogen, methane, and diborane was used as precursor and the wafer temperatures were set at 750 °C, 850 °C and 950 °C, respectively. Five-fold twin structures were observed in the samples prepared at 850 °C and they promote the increase of surface roughness. Furthermore, these twin structures may lead to the increase of boron atoms at the surface, which was verified by first-principles calculation. BDD film that contains five-fold twin structures has higher Hall mobility, lower electrical resistivity and larger hole carrier concentrations at room temperature. Besides, reactive red X-3B (200 mg/L) was fully degraded by BDD electrodes at current density of 100 mA/cm2 within 40 min using NaCl as supporting electrolyte. Overall, BDD film electrodes prepared by appropriate methods contain a large quantity of five-fold twin structures surface have excellent electrochemical properties and thereby demonstrate potential as a promising waste water degradation material.

Designing and exploiting low loading Platinum (Pt) based electrocatalysts are critical in the electrochemical reaction because of its high-efficiency in alkaline conditions for energy conversion. Herein, electrocatalysts of NiNx@Pt nanoparticles deposited on surface of functionalized carbon nanotubes (CNTs) have been prepared by simple sintering and reduction reaction, and then applied as electrocatalyst for methanol oxidation reaction (MOR), oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Under alkaline medium, a current density of 610.4 mA mg−1Pt for MOR is demonstrated which is 1.35 times higher than that of commercial 20 wt% Pt/C (451.2 mA mg−1Pt) catalysts. Besides, the NiNx@Pt/CNT electrocatalyst exhibits more excellent ORR electrocatalytic activity with an onset potential of 0.986 V and half-wave potential of 0.862 V, and an overpotential of 530 mV and low potential gap of 0.89 V for OER. The deposited NiNx nanoparticles not only serve as the center of catalyst with favorable electronic structure, but also effectively prompt the electron transport from Pt nanoparticles to carbon nanotubes. Overall, extraordinary electrocatalysis activity is presented for the versatile NiNx@Pt/CNT electrocatalyst for multiple electrochemical reactions.

Lightweight is more important in electric commercial vehicles, the static simulation analysis is first carried out on the suspension system bracket using the material of steel under three working conditions in this paper. Taking the suspension system bracket connection plate as an example, the bracket connecting plate model of the suspension system is established with thermoplastic composite materials, which is nine-layer three-dimensional model. The pre-processing, solving and post-processing procedures of the stress analysis of the part are introduced, and the stress distribution of different layers is obtained. Results show that the maximum stress of the steel bracket of the suspension system under three working conditions of triple gravity, acceleration of gravity adding steering inertia, acceleration of gravity adding braking inertia are 189.22, 92.48, and 156.9Mpa for steel, which are all less than the ultimate stress of 235Mpa. The maximum stress of each layer of the thermoplastic composite connecting plate meets the design requirements. In the case of the same ply angle, the bottom layer will bear less and less stress, the base layer will bear very little stress, and the main stress will be borne by the reinforcing material, support is provided for the application of thermoplastic composite materials on automobile chassis.

The efficient separation of water-in-oil emulsions plays significant roles in the petroleum and chemical industries, but deep purification using a single method is difficult. In this work, a combined treatment integrating a direct current electric field and medium coalescence is proposed. The device utilizes an electric field to migrate water droplets, and the fiber medium is used to intercept and capture the droplets. Water droplets migrate rapidly back-and-forth between the electrodes, causing an increase in the rate of droplet-medium collision. The combined treatment showed a significant improvement in the separation performance compared with medium coalescence or electrical demulsification alone, especially improving the ability to process fine droplets. As the applied field strength is increased, the device can achieve a better separation effect with larger throughputs and less residence time. In general, at 10 kV/cm, the separation efficiency increased by approximately 20% compared with that at 0 kV/cm.

The sand was pretreated in different ways, and the epoxy resin was selected as the cementing material to prepare the epoxy resin sand based permeable material. This kind of modification and treatment of permeable materials can obtain more superior performance and more widely used permeable materials, which provides a material basis for the construction of sponge city.

Rapid synthesis and construction of graphitic carbon nitride (g-C3N4) based heterojunctions, cost-effective metal-free photocatalysts for hydrogen evolution reaction (HER) under solar irradiation, is of highly practical significance. This work reports a one-pot microwave-assisted molten-salt (mw-ms) process to rapidly synthesize isotype triazine-/heptazine based g-C3N4 heterojunctions with highly enhanced photocatalytic HER performance using melamine as the single-source precursor. The typical sample (mw-ms-g-C3N4) was obtained by thermally polymerizing melamine molecules at 550 °C for 30 min in the media of eutectic KCl/LiCl salts under microwave irradiation in air. The analyses of phases, chemical compositions and microstructures indicate that the mw-ms-g-C3N4 sample consists of an isotype triazine-/heptazine based g-C3N4 heterojunction, taking on a plate-like morphology with a specific surface area (SBET) of 25.7 m2 g−1. Comparatively, the g-C3N4 sample synthesized via an electric-resistance molten-salt (er-ms) process at 550 °C for 240 min is composed of a triazine-based g-C3N4 phase with a SBET of 58.1 m2 g−1, whereas the samples obtained by electric-resistance heating (er, at 550 °C for 240 min) and microwave heating (mw, at 550 °C for 30 min) processes consist of a heptazine-based g-C3N4 phase. The mw-ms-g-C3N4 sample shows a photocatalytic HER rate of 1480 μmol g−1 h−1, which is 5 times that (300 μmol g−1 h−1) of the er-ms-g-C3N4 sample, 15 times that (95 μmol g−1 h−1) of the er-g-C3N4 sample and 23 times that (63 μmol g−1 h−1) of the mw-g-C3N4 sample, under the similar visible-light (λ ≥ 420 nm) irradiation. The typical apparent quantum yield of the mw-ms-g-C3N4 sample at 420 nm is up to 10.7%. The UV–vis DR spectra suggest that both the triazine-based g-C3N4 and heptazine-based g-C3N4 phases have a similar bandgap of ∼2.66 eV, whereas the Mott-Schottky analysis indicates that the triazine-based g-C3N4 phase has a more positive flat conductive potential (−0.90 V) than the triazine-based g-C3N4 phase (−1.22 V). Due to the suitable alignment of their energy bandgap structures, the isotype triazine-/heptazine based g-C3N4 hybrids in the mw-ms-g-C3N4 sample form a type II heterojunction of semiconductor/semiconductor, which provides a convenient carrier transfer path and leads to more efficient separation of photo-generated electron-hole pairs than the other samples. The synergistic effects of microwave heating and molten-salt liquid polycondensation provide a robust platform for rapid and large-scale construction of isotype g-C3N4/g-C3N4 heterojunctions as metal-free high-performance HER photocatalysts using a simple single-source precursor.

In this paper, a new morphing wing mechanism with two degrees of freedom is presented, which can realize the varying spanwise curvature and swept angle of the wing. The wing consists of segmented beams, flexible hinges, and a SMA actuator. A theoretical model of hinge’s compliance matrix is established based on linear elastic material and small displacement. A finite element analysis (FEA) is used to analyze the flexible hinge in order to produce the compliance matrix. The results validates the theoretical model. A heating method is developed to improve the output response of the SMA-actuator. The presented mechanism is fabricated and the experimental results demonstrates the potential of this mechanism.

Oxygen reduction reaction (ORR) occupies a pivotal position in fuel cell applications, and it is a challenge to obtain highly durable ORR catalysts. Herein, porous cobalt oxide microsphere growing at the surface of on nitrogen-doped graphitized-nano-diamond (CoOx/N-GND) was prepared using hydrothermal and subsequent heat treatment process. Porous cobalt oxide of high specific surface area could expose more surface Co2+that act as active sites than bulk one does. The doping of nitrogen also promotes the catalytic activity. Besides, nano-diamond (ND) ofsp3hybrid structure was used as an electronic conduction carriers of ultrahigh stability to improve the durability of catalytic composite. Prepared CoOx/N-GND shows a satisfactory half-wave potential of 0.82 V (versus RHE), which is close to that of Pt/C (0.85 V), an excellent methanol tolerance and a lower activity loss after 5000 cycles. These merits inspire the application of CoOx/N-GND as the cathode of Zn-air battery and the battery performance was evaluated in this work. In general, this work highlights an innovate approach to design and prepare highly durable catalyst.

High purity rare earth metals, including samarium, ytterbium and thulium, were prepared by vacuum reduction-distillation of each rare earth oxide with lanthanum metal. The results show that the rare earth metals of samarium and ytterbium with 4N-purity are obtained by direct vacuum reduction-distillation, and their purity is 99.99 wt% and 99.993 wt%, respectively, with respect to 75 impurities. There is a high concentration of reductant in thulium metal due to the higher reaction temperature and lower distillation velocity ratio of metallic thulium to lanthanum, so that the sublimation purification with lower temperature and high vacuum is needed. The purified thulium can reach a high purity of 99.995wt% with respect to 75 impurities. Therefore, the preparation of high purity reductant of lanthanum metal, especially of total amount control of metallic impurities, is the key step to obtain 99.99%-purity rare earth metallic samarium, ytterbium and thulium

Four β-cyclodextrin/4,4′-diphenylmethane diisocyanate/polyethylene glycol (β-CD/MDI/PEG) crosslinking copolymers with different crosslinking density were prepared and characterized as novel polymeric solid–solid phase change materials (SSPCMs) for thermal energy storage. In the SSPCMs, PEG acts as the phase change functional chain and β-cyclodextrin (β-CD) acts as the molecular framework. The results from wide-angle X-ray diffraction (WAXD) and polarizing optical microscopy (POM) show that the synthesized SSPCMs have good crystallization properties and spherocrystal morphology with smaller size than that of PEG. According to the results of differential scanning calorimetry (DSC) and thermogravimetry (TG) curves, the SSPCMs possess high phase change enthalpies, good reusability, thermal reliability and stability. It is concluded that the crosslinking density of SSPCMs is a crucial factor significantly influenced the free movement and crystallization of PEG segments, and then affects phase transition properties of SSPCMs.

As potential building sand, siliceous sea-sand and coral sand had unique physical and chemical properties compared with river sand. In order to study the effect of siliceous sea-sand and coral sand on the mechanics and water transport characteristics of concrete, the mechanical properties (including compression strength and dynamic modulus), water absorption and pore distribution of seawater and siliceous sea-sand concrete (SSC), coral aggregate seawater concrete (CASC) and tap water and desalted siliceous sea-sand concrete (DTC) were studied. The influence of volume ratio and pore volume ratio of each solid composition in concrete on the mechanics and water transport characteristics of concrete was investigated. Coral sand had larger porosity and better pore connectivity, so CASC had smaller mechanical properties and density than SSC and DTC, and also had greater water absorption. Since SSC had more salt crystals formed in macropores, the cement paste of SSC were more compact than that of DTC, and SSC had larger mechanical properties and smaller water absorption than DTC. The chemical properties of mixing materials were the main factors influencing the phase and microstructure of cement paste, which could affect the mechanical properties and water absorption of concrete. The material properties of fine aggregate directly affected the mechanical properties of concrete. However, the water absorption of concrete was related to the pore distribution, but not directly related to other properties of fine aggregate. Coarse aggregate was the main carrier for the mechanical properties of concrete, and cement paste also had some influence on them. The main water transport channel of concrete was the pore of cement paste, and the pore of fine aggregate was the auxiliary water transport channel.

A microfluidic chip driven by capillary force has the advantage of low cost and ease of manufacturing in batches, and its flow behavior is dominated by the geometry and surface characteristics of the microchannel. The design of mirochannel structures is very important for the microfluidic chips. This study presents a semi analytical method for the design of capillary microchannel. In this method, the quasi-steady state approximate solution method of the Young–Laplace equation is used to derive the capillary surface tension, and the parallel flow assumption based on the Reynolds equation is used to derive the resistance of the channel wall. A computational fluid dynamics simulation is used to provide the inlet effect coefficient and channel shape effect coefficient of this model. The availability of the semi analytical model is verified by the experiment. This model realizes the flow analysis of two-dimensional capillary flow channel with a continuous shape of the flow channel wall, providing a fast and accurate method for the structural design of the microfluidic chip driven by capillary force.

A mesa-type normal incidence separate-absorption-charge-multiplication (SACM) Ge0.95Sn0.05/Si avalanche photodiode (APD) was fabricated. The 60-μm-diameter avalanche photodiode achieved a responsivity of ~5A/W (gain=24) and ~3.1A/W (gain=20) at 98% breakdown voltage (-14.2V) under 1310nm and 1550nm illumination respectively with a low dark current of 10μA. The −3 dB bandwidth for a 60-μm-diameter APD is about 1-1.25GHz for gains from 5 to 20, resulting in a gain-bandwidth product of 25GHz for a C-band communication wavelength of 1550nm.

The influence of the interface on the amplitude and phase of the temperature wave and the relationship between the attenuation of the temperature wave and the gas-liquid two-phase physical parameters are studied during the operation of the pulsating heat pipe. The numerical simulation shows that the existence of the phase interface changes the direction of the temperature gradient during the propagation of the temperature wave, which increases the additional “thermal resistance.” The relative size of the gas-liquid two-phase thermal conductivity affects the propagation direction of heat flow at phase interface directly. The blockage of the gas plug causes hysteresis in the phase of the temperature wave, the relative size of the gas-liquid two-phase temperature coefficient will gradually increase the phase of the temperature wave, and the time when the heat flow reaches the peak value is also advanced. The attenuation of the temperature wave is almost irrelevant to the absolute value of the density, heat capacity, and thermal conductivity of the gas-liquid two phases, and the ratio of the thermal conductivity of the gas-liquid two phases is related. When the temperature of the heat pipe was changed, the difference of heat storage ability between gas and liquid will lead to the phenomenon of heat reflux and becomes more pronounced with the increases of the temperature wave.

This study deals with the preparation and characterization of the composites of polyethylene glycol (PEG)/the synthesized polymeric solid-solid phase change material (SSPCM) as novel form stable phase change material (FSPCM) for thermal energy storage. The synthesized SSPCM can play two roles in the FSPCM: the supporting material and the phase change working substance. The influence of PEG content on crystalline properties and phase change behaviors of the FSPCMs was investigated. The polarizing optical microscopy (POM) images of FSPCMs show that all FSPCMs have the spherocrystal morphology, and the spherocrystal size of SSPCM increases with the increasing of PEG percent. The results from differential scanning calorimetry (DSC) indicate that the prepared FSPCMs with different PEG contents have high thermal storage density, and the enthalpy efficiency of them is much higher than that of the traditional FSPCMs due to the synergistic phase change effect of PEG and SSPCM. The Fourier transform infrared spectroscopy (FTIR) spectrum and DSC curve of the FSPCMs after thermal cycling are almost the same as those of the original samples, which indicates that the FSPCMs have excellent thermal reliability and reusability. The work not only supplied a kind of novel FSPCMs with high performances, but also proposed a new way to solve the problem of enthalpy decline of traditional FSPCMs and synthesized polymeric SSPCMs compared with solid-liquid PCMs.

The decomposition kinetics of polymethylphenylsilsesquioxane/epoxy resin (PMPSQ/EP) systems under isothermal conditions was investigated by thermogravimetric analysis (TGA), and the isothermal kinetics equation was used to describe the thermal decomposition process. The results showed that the activation energy in the case of isothermal decomposition was first raised and then quickly decreased with increasing degree of conversion, both for EP and PMPSQ/EP (FREP) systems. Moreover, the activation energy of FREP in any degree of conversion was lower than that of pure EP. It was caused by the addition of PMPSQ, which accelerated thermal decomposition and promoted the formation of an insulating carbon layer. Thus, the flame-retardant performance of EP system containing PMPSQ was improved.

A driving coil is one significant tool for transferring electrical energy to plastic energy during electromagnetic forming, and the coil structure plays a crucial role on the distribution of magnetic field and electromagnetic force acting on the workpiece and determines the forming characteristics and magnitude. Due to the limitation of the conventional coil on forming a large and thick-walled component, this paper proposes a novel multi-layer flat spiral coil for large and thick sheets based on theoretical analysis of the relations of coil inductance, skin depth of sheets and energy efficiency. Taking electromagnetic flanging forming of a large and thick-walled sheet for example, a 3D numerical model is developed to investigate the effects of coil structure on magnetic field and sheet forming. Finally, several electromagnetic flanging experiments with 5 mm 5056 aluminum alloy sheets by a three-layer coil are carried out to validate the simulation results and a comparison of the thickness distribution and the fittability degree between the die and the sheet after one-time and two-time forming is performed. The results show that the magnetic force loading on the workpiece increases obviously with the increase of the coil layer owing to the additive effect of each layer of the multi-layer coils, and further enlarges the deformation, while the pressure acting on the coils can be controlled effectively due to the share of each layer of the multi-layer coils. The energy efficiency of the multi-layer coils increases with the increase of the skin depth and peaks at 19.6% when the skin depth is equal to the sheet thickness. The experimental results of electromagnetic flanging based on a three-layer coil coincide with the simulation results.

Molecular imprinted polymer coated S-doped TiO2 (MIP/S-TiO2) nanocomposites were successfully synthesized by a surface molecular imprinting technique using p-phenylenediamine as the functional monomer and salicylic acid as the template molecule. The structure and properties of the catalysts were characterized by X-ray diffraction, scanning electron microscopy, and UV–vis diffuse reflectance spectra. Compared with TiO2 nanoparticles, the absorption edge of MIP/S-TiO2 nanocomposites was enhanced over the whole range of visible region. Moreover, MIP/S-TiO2 nanocomposites showed higher adsorption capacity for salicylic acid than for S-TiO2 nanoparticles. The rate constant for the photodegradation of salicylic acid over MIP/S-TiO2 nanocomposites was 1.7 times that of salicylic acid over S-TiO2 nanoparticles, which was attributed to the molecular recognition ability of MIP/S-TiO2 nanocomposites for the target molecules.

Two divalent transition metal complexes of EDT-TTF-4-py (EDT-TTF-4-py = 4-ethylenedithiotetrathiafulvalenyl-pyridine) have been prepared and characterized in micro and bulk crystal forms. These hybrid microstructures were synthesized by coordinative self-assemble through a solution process. The isostructural Cu(hfac)2 and Mn(hfac)2 (hfac = hexafluoroacetylacetonate) complexes crystallize in the monoclinic space group P21/c. Two pyridyl N atoms from two different molecules of EDT-TTF-4-py are coordinated in the trans configuration to the metal ion of M(hfac)2 to form an octahedral complexes. The results of the elemental analysis, FT-IR, SEM-EDX and PXRD, show the chemical composition of the microstructures which are same as that of bulk crystals. Moreover, these two microstructure compounds are precursor for both conducting and magnetic materials. These investigations show the intriguing potentials of the coordinative bond in the development of multifunctional hybrid microstructures.

Isothermal decomposition behaviors which take place in the polymer matrix are of paramount importance in the understanding of polymer flame retardancy and processing property. In the present study, the thermal decomposition of polyepoxyphenylsilsesquioxane/epoxy resin (PEPSQ/EP) systems was investigated by the means of isothermal thermogravimetry at temperatures of 300–330°C in nitrogen. The isoconversional method was used to calculate the activation energy of PEPSQ/EP systems in the case of isothermal decomposition. The results showed that the activation energy was first raised and then with the increasing of degree of conversion quickly decreased. Furthermore, the activation energy of PEPSQ/EP system is less than that of pure EP in any degree of conversion, which is attributed to the addition of the PEPSQ.

In this paper CuInS 2 solar cells have been numerically simulated based on a one-dimensional device physics simulator: Analysis of Microelectronic and Photonic Structures. Solar cells having a typical structure Al/ZnO:Al/ n -CdS/ p -CuInS 2 /Mo have been modeled. Various factors that affect cell performance have been studied, such as thickness and bandgap of the CuInS 2 absorber layer, and thickness of the CdS buffer layer. The photovoltaic parameters are determined from the current density–voltage curves. The solar spectral response and recombination mechanism of the cells are represented by quantum efficiency– λ curves and net recombination rate–position curves, respectively. In this study, a simulated efficiency of 20.4% has been obtained with open-circuit voltage of 0.94 V, short-circuit current density of 26.2 mA/cm 2 and fill factor of 0.84 for the CuInS 2 solar cell with a bandgap of 1.40 eV. It is found that optimal thicknesses of the CuInS 2 absorber layer and the CdS buffer layer are around 2000 and 50 nm, respectively, while optimal bandgap of the CuInS 2 absorber layer is 1.40 eV.

In order to improve the compatibility of bisphenol F epoxy resin with the liquid oxygen, the hexabromocyclododecane and the antimony trioxide were added to bisphenol F epoxy resin, and then cured resin was mechanically impacted according to ASTM D-2512-95. The microstructure and the surface element compositions of the specimen before and after the mechanical impact were investigated and analyzed by scanning electron microscopy and X-ray photoelectron spectroscopy, respectively. These results indicated that the addition of the antimony trioxide was favorable to help the hexabromocyclododecane to improve the compatibility of the bisphenol F epoxy resin with liquid oxygen. The liquid oxygen compatibility mechanism and the synergistic effect of the hexabromocyclododecane and antimony trioxide on the improvement of compatibility of bisphenol F epoxy resin with liquid oxygen were analyzed in detail.

A series of chiral poly(ether sulfone)s containing (S)-binaphthyl unit were synthesized via nucleophilic substitution polycondensation. The as-synthesized polymers were characterized by NMR. The molecular weights of these polymers were calculated by viscosity and gel permeation chromatography. The thermal stability was measured by TGA. The optical activities of the polymers were studied by circular dichroism and optical rotation. It was found that introducing more reactive 2,2′-biphenol monomer to partly substitute the binaphthol monomer could increase the molecular weight of the polymer from 4.1 × 104 to 9.8 × 104 g mol−1. Meanwhile, the thermal stability increased and the decomposition temperature rose from 447 to 518 °C, with the optical activity of the polymer well preserved. However, the value of the specific optical rotation decreased with increasing biphenol to binaphthol molar ratio. In addition, the optical rotation direction of the polymer was contrary to that of the pristine binaphthol monomer, which indicated that the chiral polymers formed a secondary structure. © 2013 Society of Chemical Industry

Metastable transition metal oxides were used as precursors to synthesize transition metal nitrides at low temperature. Amorphous MoO 2 was prepared by reduction of (NH 4 ) 6 Mo 7 O 24 solution with hydrazine. As-synthesized amorphous MoO 2 was transformed into fcc γ-Mo 2 N at 400 °C and then into hexagonal δ-MoN by further increasing the temperature to 600 °C under a NH 3 flow. The nitridation temperature employed here is much lower than that employed in nitridation of crystalline materials, and the amorphous materials underwent a unique nitridation process. Besides this, the bimetallic nitride Ni 2 Mo 3 N was also synthesized by nitridating amorphous bimetallic precursor. These results suggested that the nitridation of amorphous precursor possessed potential to be a general method for synthesizing many interstitial metallic compounds, such as nitrides and carbides at low temperature.

A new Nylon 11 (PA11)/polyethylene-octene (POE) blends compatibilized by maleic anhydride grafted mixture polyethyleneocten (POE-g-MAH) was prepared through melt blending method. The isothermal crystallization kinetics and melting behaviors of PA11/POE blends were investigated in detail by differential scanning calorimetry (DSC) and polarized optical microscope. The n values of PA11 blending with POE or POE-g-MAH are almost similar with pure PA11, which indicates that the effect of POE and POE-g- MAH on nucleation and growth of PA11 crystal is slight. The overall crystallization rate of PA11/POE blends are higher than ones of pure PA11 at the same crystallization temperatures, but they decrease significantly when POE-g-MAH is added into PA11/POE blends. DSC heating curves of both PA11 and its blends exhibit two melting peaks, but the two melting peak become weaker when POE-g-MAH is add into PA11/POE blend systems. And the spherulite size is reduced signifi cantly by the addition of POE-g-MAH compared with pure PA11 and PA11/POE blends.

This paper describes a method for obtaining the pressure reflection coefficient by using a half-wave layer. Two transducers were placed in reference liquid and test liquid respectively. The reference and test liquid were separated by the thin half-wave layer. Both transducers could operate in two modes. One acted as a transmitter and worked in pulse-echo mode, and the other operated in receiver mode. By adjusting the frequency of drive signal according to the thickness and material property of the half-wave layer, it was possible to generate the maximum interference signal of multiple waves reflected at the two interfaces of the layer. Therefore, the amplitude of reflection wave in steady-state depended only on the reflection coefficient at the interface between the half-wave layer and the test liquid. The effects of the signal-to-noise-ratio and the half-wave layer attenuation on the uncertainty characteristics of the pressure reflection coefficient were discussed. The experimental results showed high accuracy for measurement of reflection coefficient.

The surface mesh defining the outer boundary of the part is used in the warpage analysis of plastic injection moulding. The structure is represented as a perfect bonding of two half‐thickness plates which are modelled as flat shell elements with their reference surfaces on the outer boundary of the part. Bonding is assured by multi‐point constraints. After analysing several popular constraint imposition methods of master‐slave elimination, penalty augmentation and Lagrange multiplier adjunction, a Lagrange multiplier based elimination method is proposed. By comparison with the experiments and Moldflow, the presented model shows a high performance in computation accuracy.

Nanoparticle has been a hot topic because of its excellent properties comparing to the corresponding bulk material in many aspects. Here we described a successful use of nickel nanoparticle prepared by a reduction of Ni 2+ with hydrazine to synthesize metastable nanocrystalline Ni 3 N at 513 K in NH 3 flow. In comparison, a nickel precursor prepared by a reduction of NiO in hydrogen was not nitrided when it was treated with NH 3 at 533 K. The samples were characterized by X-ray diffraction (XRD) and transmission electron microscope (TEM). The XRD patterns showed that the nickel particles prepared by hydrazine reduction had a smaller crystalline size (18.3 nm) than that of nickel particles from hydrogen reduction (49.5 nm), resulting in a low nitriding temperature. As-synthesized Ni 3 N had spherical morphology and average particle size of ∼30 nm from TEM observation. The temperature-programmed decomposition of Ni 3 N showed that it began to decompose at 540 K and was finally transformed into metallic nickel.

This paper investigated the formation of chain aggregates from fine particles suspended in gas stream onto material surfaces under the action of electric field. The results showed that the shape of aggregate formed on material surface was greatly influenced by the field intensity and the surface condition of materials. In a weak electric field without corona discharge, particles tended to form clustered aggregates on a metal plate with smooth surface, but on a metal mesh and a porous alumina substrate, to form chain aggregate. On the other hand, in a corona discharge field, these surfaces were coated uniformly. Consequently, for forming chain aggregates on material surface, an electric field without corona discharge and a rough surface are necessary conditions. On rough surface, chain aggregates of dielectric particles or conductive particles grew from the protrusions of the surface and could form a rough and porous layer. When the external electric field was removed, the chain aggregates remained long time due to the Van der Waals forces. After sintered at proper temperature, the chain aggregates became fiber-like. The results indicate that the formation of chain aggregate can be controlled by electrostatic force, and sintering can be used as a method for increasing their mechanical strength.

Sm 3+ -doped fluoroborate ceramics (BaO-ZnO-Al 2 O 3 -B 2 O 3 -NaF) were fabricated as a potential material in illumination and display. The density, surface modality, microstructure and fluorescence were measured and characterized. The ceramics were well densified without pores and they were proved to be amorphous. Under blue and UV light excitations, the opaque fluoroborate ceramics doped with Sm 3+ absorbed the most of excitation radiation and emited intense reddish orange light. The emission spectrum of Sm 3+ -doped fluoroborate ceramics under 404 nm excitation consisted of four intense emission bands peaking at 564, 600, 645 and 708 nm, respectively, and the 600 nm reddish-orange emission band was the most intense. Excitation and emission spectra indicated that commercial UV and blue laser diodes, blue and bluish-green LEDs and Ar + optical laser were powerful pumping sources for the fluoroborate ceramics. The rare earth doped ceramics with various visible emissions were useful for developing new color light sources, fluorescent display devices and UV sensors.

This work deals with the oxygen-plasma-induced epoxy resin coating process on the surface of Twaron fiber in order to get a strong interfacial adhesion between the fibers and epoxy matrices. The influence of oxygen plasma treatment time on the surface morphologies and free energies of Twaron fibers and the interlaminar shear strength (ILSS), water absorption and fracture mechanisms of the composite were investigated. Surface chemical properties were studied by diffuse reflectance fourier transform infrared spectroscopy (FTIR). The fiber surface morphologies and wettability were analyzed by atomic force microscope (AFM) and dynamic contact angle analysis (DCAA), respectively. The interfacial adhesion performance of the Twaron fiber-reinforced epoxy composite was measured by ILSS and water absorption tests. The fracture mechanisms of composites were examined by scanning electron microscope (SEM).

A glassy carbon electrode (GCE) modified by graphene (GR) and dicyclohexyl phthalate (DCHP) using for the determination of rutin in tea was fabricated and investigated, which displayed excellent electrochemical performance owing to the formation of highly conductive GR film and the binder of DCHP on the electrode surface. Different electrochemical methods such as cyclic voltammetry and electrochemical impedance spectroscopy were used to investigate the electrochemical behaviors of rutin on GR/DCHP/GCE with the electrochemical parameters calculated. Under the optimized conditions, the oxidative peaks increased linearly with rutin concentrations in the ranges from 1.0 to 2.5 uM with a limit of detection as low as 0.07 uM (S/N= 3). The modified electrode was proved to have excellent selectivity, stability and repeatability, which was successfully employed to the determination of rutin content in tea with satisfactory results.

A simulation research concerning temperature field of multi-pad hydrostatic thrust bearing having rectangular cavity, sector cavity, ellipse cavity and I-shaped cavity was described in order to solve the thermal deformation of the hydrostatic thrust bearing in the heavy CNC equipment. The Finite Volume Method of CFX has been used to compute three-dimensional temperature field of gap fluid between the rotation worktable and the base. This study theoretically analyzes the influence of cavity shape on the bearing temperature performance according to computational fluid dynamics and lubricating theory. It has revealed its temperature distribution law. The simulation results indicate that an improved characteristic will be affected by cavity shape easily. Through this method, the safety of a multi-pad hydrostatic thrust bearing having different cavities can be forecasted, and the optimal design of such products can be achieved, so it can provide reasonable data for design, lubrication, experience and thermal deformation computation for hydrostatic thrust bearing in the heavy CNC equipments.

Four kinds of nylon 6/POSS nancomposites films were synthesized by the phase inversion process. X-ray diffraction (XRD), differential scanning calorimetry (DSC) and water contact angle (CA) measurements were used to characterize the interactions between POSS and PA6 chains. It was demonstrated that the interactions between octaammonium POSS (OA-POSS) and PA6 chains was the greatest compared with aminopropylisobutyl POSS (AB-POSS), aminopropylphenyl POSS (AP-POSS), and Octamethyl POSS (OM-POSS). OA-POSS could achieve the uniformed dispersion state in PA6 matrix. Scanning electron microscopy (SEM), energy dispersive X-ray (EDX) and polarized optical microscopy (POM) were used to investigate the migration behaviors of POSS. X-ray photoelectron spectroscopy (XPS) was qualitatively used to study the migration behaviors as well. It was found that OA-POSS has the greatest migration behaviors compared with other POSS. Finally, proposed migration mechanism was discussed.