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In this work, TiC coating was fabricated by atmospheric plasma spray (APS) technique and its tribological performances sliding against stainless steel, Si3N4 and WC-Co were evaluated using ball-on-disk tests under 50 N load. The results indicated that the TiC coating exhibited diverse tribological behaviors. The TiC/Si3N4 tribopair showed the lowest friction coefficient with a significant fluctuation. The TiC/steel tribopair exhibited the lowest coating wear rate, while the TiC/WC-Co tribopair had the highest coating wear rate among the three tribopairs. The tribological mechanisms were tentatively explained based on the observation of worn surfaces. This work might provide some clues for the applications of TiC coatings.

In this work, TiN, TiC and TiB2 coatings were fabricated by atmospheric plasma spray (APS) technique. The phase composition, microstructure, mechanical and tribological properties of the three kinds of coatings were investigated and compared in detail. The results showed that all the coatings were relatively homogenous with lamellar microstructure, while oxidation phenomenon occurred during the deposition processes. The TiN owned the highest oxygen content, while the TiB2 coating presented the highest roughness and porosity. The elastic modulus and hardness values of the TiC coating were about 189.7 ± 26.6 GPa and 7.7 ± 0.7 GPa, respectively, which were higher than those of the TiN and TiB2 coatings. The TiC coating exhibited the best tribological property with the lowest friction coefficients and wear rates under both low and high loads against WC-Co ball. The wear mechanisms of the three kinds of coatings were analyzed as well.

A bi-dispersed bubble model incorporating lateral forces and bubble-induced turbulence is employed to simulate hydrodynamics in an up flow jet-loop reactor (JLR) operated in gas–liquid co-injection mode. In the model the bubble swarm effect on the drag force was differently described for the large and small bubble phases, where the drag force for the large bubble decreases with the gas holdup in accordance with the wake acceleration effect, while for the small bubble the drag force increases with the gas holdup in consideration of the hindrance effect of the bubble swarm. The simulated radial profiles of gas holdup and axial liquid velocity agree with the cold experiments, which shows that the different description of drag forces for the large and small bubbles is reasonable for correctly simulating the effect of superficial gas velocity on liquid circulation velocity. Effects of draft tube position (HC) and cross-sectional area ratio of riser to downcomer (Ar/Ad) are evaluated by model simulation. The results show that with the increase of HC and Ar/Ad, both overall gas holdup and liquid circulation velocity reach a maximum at HC = 0.06 m and Ar/Ad = 0.44, respectively. Recommendatory geometric parameters for the JLR design is: 0

Hydrodynamics in an up flow jet-loop reactor (JLR) is experimentally investigated. The overall gas holdup, radial and axial distributions of local gas holdup and liquid velocity are presented. A modified drift-flux model was developed for correlating the “S-shape” relationship of overall gas holdup and gas velocity. Experiments show that the gas–liquid co-injection mode results in larger gas holdup and liquid circulation velocity than those of the gas jet alone mode. Liquid velocity distribution is more prone to reach the fully developed regime than the gas holdup, and the gas–liquid co-injection promotes the flow development. Comparison of JLR with the conventional bubble column (BC) and airlift reactor (ALR) shows that the JLR has a largest liquid circulation velocity, which is mostly beneficial to liquid mixing and solid suspension.

Lead-bismuth (Pb-Bi) alloys, as a superconducting material, have been widely studied at their superconducting transition temperatures and the critical magnetic fields for different composition ratios. Most of experimental studies focused on the stable ε phase formed at high temperatures, but less on the Pb-Bi alloys grown at low temperatures. So far, the structural and superconducting properties of the low-temperature Pb-Bi phases are far from good understanding. Here, we report our investigation of structural and superconducting properties of a low-temperature phase of Pb-Bi alloy. The Pb-Bi alloy films with a nominal thickness of about 6 nm are prepared by co-depositing Bi and Pb on Bi(111)/Si(111)-(7 × 7) substrates at a low temperature of 100 K followed by annealing at a treatment of 200 K for 2 h. The structural and superconducting properties of the Pb-Bi alloy films are characterized in situ by using low-temperature scanning tunneling microscopy/spectroscopy (STM/STS). It is observed that the spatially separated phases of nearly pure Bi(111) domains and Pb1–xBix alloy domains are formed in the films, where these phases can be identified by their distinct differences in the atomic structure and the distributions of step heights in the atomically resolved STM images, as well as by their distinguished STS spectra. The Pb1–xBix alloy phase presents the structure of Pb(111), in which about x ≈ 0.1 Bi is substituted for Pb. The STS spectra show that the Pb1–xBix alloy phase is superconducting, with a transition temperature Tc = 7.77 K derived from the variable-temperature measurements. This transition temperature is higher than that in pure Pb film (6.0–6.5 K), which can be well explained by the Mattias rules, with considering the fact that the average number of valance electrons increases after Bi atoms with five valance-electrons have been substituted for Pb atoms with four valance-electrons. The analysis shows that the ratio \begin{document}$ 2\Delta (0)/{k_{\rm{B}}}{T_{\rm{C}}}$\end{document} is about 4.94 with the superconducting gap \begin{document}$ \varDelta (0) = 1.66$\end{document} meV at 0 K, indicating that the Pb1–xBix alloy is a strongly-coupled superconductor. The non-superconducting Bi(111) and the superconducting Pb1–xBix alloy domains form an in-plane superconductor-normal metal-superconductor (S-N-S) Josephson junction. The proximity effect in the Bi(111) domains is measured at different N-S junctions, which suggests that the lateral superconducting penetration length in Bi(111) might be affected by the area of the quasi-two-dimensional interface. The superconducting gap in the Bi(111) region with a narrow width of 23 nm in an S-N-S Josephson junction is found to be greatly enhanced due to the existence of multiple Andreev reflections. Since Bi can host potential topological properties, the lateral Bi(111)-Pb1–xBix heterostructures, because of the existing proximity effect, could have potential applications in exploring the novel topological and superconducting phenomena.

Bamboo shinai is a practice sword for kendo which is the Japanese traditional fencing. The effectiveness of the shock absorption of the bamboo shinai has been shown in our previous study. Although shinai is usually made of bamboo, it is also made of carbon fiber reinforced plastic (CFRP). The impact response of bamboo shinai and CFRP shinai is compared. As a result, the difference of peak value of impact force between bamboo shinai and CFRP shinai against similar initial velocity is small. Impact response measurement of each shinai has been carried out using the Levitation Mass Method (LMM) which has been proposed by us. In this method, a mass, which is levitated with a pneumatic linear bearing and hence affected by negligible friction, is made to collide with a shinai under test. Because bamboo is natual product, resource of suitable bamboos for shinai is limited. On the other hand, carbon-fiber-reinforced-plastic (CFRP) can be designed to be suitable for a shinai, which has a fixed shock absorption characteristic for an application to the structure of robot arms. Therefore, if the shock absorption characteristic of CFRP shinai is the same as that of bamboo shinai, CFRP shinai is more suitable for the structure of robot arms.

The overpressures, flame velocities and flow speeds were investigated in closed-end and open-end tubes via numerical simulations. Our results suggest that the tube geometry influences the evolution of these parameters. The peak overpressure initially decreased and eventually increased with the aspect ratio in both types of tubes. The flow speed initially increased and then decreased with the propagation distance in the closed-end tube, but it increased with increasing distance in the open-end tube. Empirical equations relating the peak overpressure and the peak flow speed are presented. The flame velocities in the open-end tubes were always greater than those in the closed-end tubes, especially the maximum flame velocity. The open end promoted flame acceleration, while the closed end resulted in near-wall deceleration. The results provide a reference for future limited-space gas explosion studies.

Impact response of contact lenses is measured using the Levitation Mass Method (LMM). In the LMM, a small mass collides with contact lenses and the impact force is measured with high accuracy as the inertial force of the moving part. A pneumatic linear bearing is used to achieve linear motion with sufficiently small friction acting on the moving part. Hysteresis loop and consumed energy as mechanical characteristics of contact lenses are also calculated.

Using recycled concrete aggregate (RCA) in an asphalt mixture has many economic and environmental benefits for our society. However, due to the poor adhesion of RCA to asphalt binder, the replacement of normal aggregate with RCA leads to a reduction in the properties of asphalt mixture. This study presents a new approach to overcome this deficiency by treating RCA with microbial carbonate precipitation to develop chemical bonds between RCA and asphalt binder. This study first investigates the effect of this surface treatment on the properties of RCA. The experimental results showed that the capillary water absorption and porosity of the treated-RCA could be reduced by 86.5% and 32%, respectively, as compared to those of the untreated-RCA. In addition, this study investigates the influence of this surface treatment on the interfacial behavior of RCA to asphalt binder by means of standard boiling test and direct tension test. According to the test results, the adhesion behavior of the treated-RCA to asphalt binder could be improved by 2 grades as compared to the asphalt mixture with untreated-RCA. Moreover, the bonding strength of treated-RCA to asphalt binder was also improved by 55%. The formation of chemical affinity between treated-RCA and asphalt binder, as shown in FTIR spectra, is the explanation for the enhancement in the bonding strength and water susceptibility for the treated-RCA–asphalt mixture.

Pure (K0.5Na0.5)NbO3 and 0.98(K0.5Na0.5)NbO3-0.02LaFeO3 ceramics (abbreviated as KNN and 0.98KNN-0.02LF, respectively) were prepared by a solid state reaction approach, and their crystal structure, dielectric and ferroelectric properties were investigated. Pure KNN and 0.98KNN-0.02LF ceramics are the orthorhombic struc- ture and pseudo-cubic perovskite structure, respectively. Dielectric measurements revealed that the dielectric permit- tivity curves of 0.98KNN-0.02LF ceramics present two anomalies compared with pure KNN: (i) The orthorhombic- tetragonal transition (TO-T) and the tetragonal-cubic transition (TT-C) shifts to lower temperatures. (ii) The phase transi- tion temperature range around the temperature of the maximum dielectric permittivity (Tm) becomes more and more broad. In addition, 0.98KNN-0.02LF ceramics exhibited a very stable temperature dependence of dielectric permittiv- ity with permittivity maximum near 2000 and dielectric loss less than 4% in the temperature range of 0-400℃. The relaxation behavior of the 0.98KNN-0.02LF ceramics is interpreted in terms of polar nanoregions (PNRs) caused by cations disorder. The P-E hysteresis loops further confirms the relaxor behavior in 0.98KNN-0.02LF ceramics.

Mn-doped ZnS nanoparticles were prepared by the Sol-Gel process in this paper,and the influence of doping ion concentration on crystal structures and luminescent properties of ZnS:Mn nanoparticles was discussed.The structures of the samples were characterized by an X-ray diffractometer(XRD).The results show that the as-prepared ZnS:Mn nanoparticles belong to the cubic sphalerite structure.The parvafacies do not occur when Mn2+-doping concentration reaches 6% and the average particle sizes of nanoparticles decrease with the increase of doping concentration.Photoluminescence(PL) spectroscopy and fluorescence spectrum results show that the emission wavelengths of ZnS:Mn nanoparticles around 590 nm can be adjusted by changing the concentration of the ions.In addition,the influence of temperature on morphology and luminescent properties of nanoparticles was studied.The result observed from a high resolution transmission electron microscopy(HRTEM) shows that the average particle sizes of ZnS∶Mn samples increase to about 20 nm after ageing for 1 h at the temperature of 50 ℃.The heating ageing is beneficial to Mn2+ fluorescence produced at 590 nm for ZnS∶Mn nanoparticles.

A bottom emitting organic light-emitting devices was fabricated by depositing Alq as capping layer to the glass substrate.The device structure were Glass/Alq(x nm)/Al(15 nm)/MoO3(30 nm)/ NPB(60 nm)/Alq(65 nm)/LiF(1 nm)/Al(150 nm).By studying the radiation characteristics of the devices,it was found that the variation of the EL emission due to the capping layer can be entirely accounted for a change in optical interference effects.The complex interplay between wide-angle and multiple-beam interference can be controlled via the optical thickness of the dielectric capping layer on top of the cathode.Semitransparent Al film was anode.The capping layer deposited to the glass substrate formed microcavity devices with cathode.By changing the thickness of capping layer to adjust the microcavity length,the center wavelength EL spectra of OLED was red-shifted.

Results of Zn based anode production by semi-liquid pressure method have been presented. Microstructure, electrochemical characteristics and protective effectiveness of the newly developed anodes have been demonstrated in relation with products manufactured by traditional method. The newly developed samples had a potential of -1.1462 V and corrosion rate of 0.27 mpy in comparison of -1.223 V and 0.4894 mpy for traditionally prepared anodes.

Under classical particle dynamics, the interaction process between intense femtosecond laser pulses and icosahedral noble-gas atomic clusters was studied. Our calculated results show that ionization proceeds mainly through tunnel ionization in the combined fleld from ions, electrons and laser, rather than the electron-impact ionization. With increasing cluster size, the average and maximum kinetic energy of the product ion increases. According to our calculation, the expansion process of the clusters after laser irradiation is dominated by Coulomb explosion and the expansion scale increases with increasing cluster size. The dependence of average kinetic energy and average charge state of the product ions on laser wavelength is also presented and discussed. The dependence of average kinetic energy on the number of atoms inside the cluster was studied and compared with the experimental data. Our results agree with the experimental results reasonably well.

The grain orientation techniques of piezoelectric ceramics have attracted considerable at- tention because the grain oriented piezoelectric ceramics possess higher piezoelectric properties than polycrystalline ceramics and have the same Curie temperature as polycrystalline ceramics. In this paper, the research progress and trend of grain orientation techniques of piezoelectric ceramics are summarized with emphases on directional solidification technology, multilayer grain growth technique, templated grain growth and reactive-templated grain growth technique. The future for the developments of grain orientation techniques of piezoelectric ceramics are also proposed.

The calculation formulas of dielectric and piezoelectric constants of 1-3-2 piezoelectric composites were deduced, combine the model of 1–3 piezoelectric composites by Chan and the Newnham's series...

The carbides of NdDy0.2Fe12−yMoyC0.6 (y = 1.5,2) crystallized in the ThMn12-type structure have been successfully synthesized by arc melting method, followed by a heat treatment. The magnetic properties are strongly enhanced with the addition of carbon. Upon the carbonation the saturation magnetization Ms is increased by about 20 emu/g and the Curie temperature Tc is enhanced by 40–70 K. The spin reorientation (SR) temperature decreases from 125 K for NdDy0.2Fe10Mo2 to 55 K for NdDy0.2Fe10Mo2C0.6 indicating the change of magnetocrystalline anisotropy in the Nd sublattice. It is found that the intrinsic magnetic properties of the carbides can be improved by further nitrogenation. The composite carbon–nitrogen compounds show a Tc~560 K, Ms~105 emu/g and Ha (anisotropy field) ~86 kOe for NdDy0.2Fe10Mo2C0.6Nz and a Tc~628 K, Ms~119 emu/g and Ha~115 kOe for NdDy0.2Fe10.5Mo1.5C0.6Nz. These magnetic properties are even better than those of simple nitrides, suggesting that these compounds can be considered as a good candidate for permanent magnet applications.

A sample with nominal composition YFe10.5TiB0.5 has been prepared through careful processing. X-ray diffraction analysis revealed that the main phase in the sample is in the tetragonal ThMn12-type structure (space group, I4/mmm),-and a small amount (less than 3%) of alpha-Fe exists as a second phase. Neutron diffraction measurements indicated that, in the tetragonal structure, the boron atoms occupy the 8i sites, substituting for a few Ti atoms, while the substituted Ti atoms enter the interstitial 2b sites. The real composition of the main phase was determined to be Y(Fe11.04Ti0.52B0.43)Ti-0.39.

In this paper, a broadband metamaterial absorber is designed based on a hybrid substrate consisting of the dielectric and magnetic materials. The absorber is composed of the resistance film, dielectric layer, magnetic layer, and metal backboard. Numerical simulation of the absorbing properties is performed by means of the finite-difference time-domain method, and the bandwidth of the reflectivity below -10 dB is optimized by the genetic algorithm. Simulated results indicate that a bandwidth of reflectivity below -10 dB can be achieved over the frequency range from 7.8 to 18 GHz when the thickness of the absorber is only 2.5 mm. The proposed metamaterial absorber has many advantages, such as thin thickness, broadband, and polarization insensitivity. The operation mechanism of the absorber has also been analyzed and discussed within the model of equivalent circuit. In the end, an absorber sample is fabricated based on the design. It is found that the experimental result is well consistent with the design requirements.

The strip casting (SC) technique is employed to fabricate Nd(Fe,Mo)12Nx magnets. The crystallographic structure, intrinsic and permanent magnetic properties, as well as the microstructures of the compound are investigated. There are prominent advantages for the SC Nd-Fe-Mo alloys and their nitrides when compared with the samples prepared by the conventional casting (CC) method: (1) SC technique rebounds to the formation of the compounds crystallizing in a ThMn12-type structure. A single-phased host alloy Nd(Fe,Mo)12 can be directly prepared by strip casting without any isothermal annealing. Accordingly, lower energy cost and less rare earth demand notablely benefit the manufacture processing from a point of economizing. (2) The intrinsic magnetic properties, such as Curie temperature Tc, saturation magnetization Ms and anisotropy field Ha of the SC sample exceed the CC sample due to a phase forming condition with less-Mo-depended. (3) The microstructure studies also demonstrate that the SC compound contains finer grains, better-proportioned phase distribution than the CC compound. Optimized final particles are observed aligned in their easy axis and the energy product of powder sample is up to (BH)max ~ 22 MGOe (176kJ/m3).

The interaction between intense femtosecond laser pulses and hydrogen atomic clusters is studied by a simplified Coulomb explosion model. The dependences of average proton kinetic energy on cluster size, pulse duration, laser intensity and wavelength are studied respectively. The calculated results indicate that the irradiation of a femtosecond laser of longer wavelength on hydrogen atomic clusters may be a simple, economical way to produce highly kinetic hydrogen ions. The phenomenon suggests that the irradiation of femtosecond laser of longer wavelength on deuterium atomic clusters may be easier than that of shorter wavelength to drive nuclear fusion reactions. The product of the laser intensity and the squared laser wavelength needed to make proton energy saturated as a function of the squared cluster radius is also investigated. The proton energy distribution calculated is also shown and compared with the experimental data. Our results are in agreement with the experimental results fairly well.

The R(Fe, Mo)12 (R=Nd, Y, Dy) samples have been prepared and measure d by x-ray diffraction at different temperatures. The crystal lattice constant s and degree of the thermal expansion along the different axes are calculated. As a result, we consider that the abnormally thermal expansion of R(Fe, Mo)12 compounds is mainly determined by the Fe-Fe interaction. According to structural parameters of Nd(Fe, Mo)12, the anomaly is caused not on ly by the short Fe-Fe interaction as the previous explanation on other R-Fe inte rmetallic compounds but also by the other strongly positive Fe-Fe interactions. The mechanism of the substitution by Mo affecting the thermal expansion anomal ies is also discussed.

[EN] The new zeolite NUD-3 possesses a three-dimensional system of large pore channels that is topologically identical to those of ITQ-21 and PKU- 14. However, the three zeolites have distinctly different frameworks: a particular single 4-membered ring inside the denser portion of the zeolite is missing in PKU-14, disordered in ITQ-21 and fully ordered in NUD-3. We document these differences and use molecular simulations to unravel the mechanismbywhich a particular structure directing agent dication, 1,10-(1,2-phenylenebis(methylene))bis(3-methylimidazolium), is able to orient this inner ring., Spanish Ministry of Science Innovation and Universities (MAT2015-71117-R, PID2019-105479RB-I00 and PID2019-107968RB-I00 projects, AEI, Spain and FEDER, EU), the National Natural Science Foundation of China (No. 22071099, 21673115, 21527803, 21871009, and 21601004), top talent cultivation program of Anhui Educational Committee (gxgwfx2018051), and the Swedish Research Council (VR) and the Knut and Alice Wallenberg Foundation (KAW). Synchrotron experiments were performed at beamline BL04 (MSPD) at ALBA Synchrotron with the collaboration of ALBA staff, and special thanks are given to A. Manjo´n for support in collecting the data and for helpful comments and suggestions. Z. R. G. specially thanks Yingxia Wang of Peking University for her kind suggestions and help with this paper. Centro Te´cnico Informa´tico- CSIC is acknowledged for running the calculations, and BIOVIA for providing the computational software. We acknowledge support of the publication fee by the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI).