Using steel slag and charcoal as raw materials, the steel slag/charcoal nano-/micro-composites with magnetic-resistance mixed loss mode were fabricated by a high-performance milling process, and then the composition, ...
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Using steel slag and charcoal as raw materials, the steel slag/charcoal nano-/micro-composites with magnetic-resistance mixed loss mode were fabricated by a high-performance milling process, and then the composition, phase structure, morphology, and electromagnetic (EM) characteristics of the products were characterized by XRD, EDS, SEM, and vector network analyzer, respectively. The results showed that EM characteristics of the products were strongly dependent on the content of the charcoal (WCharcoal). The real and imaginary parts of the permittivity of the steel slag/charcoal nano-/micro-composites significantly increased with the increasing WCharcoal. Among them, the steel slag/charcoal composites with WCharcoal=50wt% exhibited the best EM-wave absorption performance, with a maximum reflectivity value of -33.4dB, the effective bandwidth 15.2GHz(<-10dB) and 8.6 GHz (<-20 dB), respectively, which is a consequence of enhanced dielectric loss and a proper EM matching.
This paper introduces a numerical method for predicting the effective elastic module of ZrB2-based composites, which includes a random generation-growth method for generating microstructures of ZrB2-based composites b...
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This paper introduces a numerical method for predicting the effective elastic module of ZrB2-based composites, which includes a random generation-growth method for generating microstructures of ZrB2-based composites based on existing statistical macroscopic geometrical characteristics and a highly efficient lattice Boltzmann algorithm for solving the governing equations on the multiphase microstructures. The effective elastic module of random ZrB2-based materials is analyzed with different parameters by the present method, including effects of component size and material anisotropy. The simulation results indicate this numerical method's effectiveness and robustness by comparing the predictions with experimental data and other theoretical models.
The back-propagation neural （BPN） network was proposed to model the relationship between the parameters of the dieless draw- ing process and the microstrecmres of the QSi3-1 silicon bronze alloy. Combined with image...
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The back-propagation neural （BPN） network was proposed to model the relationship between the parameters of the dieless draw- ing process and the microstrecmres of the QSi3-1 silicon bronze alloy. Combined with image processing techniques, grain sizes and grain-boundary morphologies were respectively determined by the quantitative metallographic method and the flactal theory. The outcomes obtained show that the deformed microstructures exhibit typical fractal features, and the boundaries can be characterized quantitatively by ffactal dimensions. With the temperature of 600-800℃ and the drawing speed of 0.67-1.00 mm-s-1, either a lower temperature or a higher speed will cause a smaller grain size together with an elevated fractal dimension. The developed model can be capable for forecasting the microstructure evolution with a minimum error. The average relative errors between the predicted results and the experimental values of grain size and fractal dimension are 3.9% and 0.9%, respectively.
Graphene was prepared and used as an adsorbent for removal of cationic red X-GRL from aqueous solutions. The physico-chemical properties of graphene were characterized by the transmission electron microscope (TEM), th...
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Graphene was prepared and used as an adsorbent for removal of cationic red X-GRL from aqueous solutions. The physico-chemical properties of graphene were characterized by the transmission electron microscope (TEM), the Brunauer-Emmett-Teller (BET) specific surface area measurement, atomic force microscope (AFM), and Raman microscope. The adsorption properties of cationic red X-GRL onto graphene were studied as a function of pH, adsorbent dosage, contact time, and temperature. Kinetic data were well fitted by a pseudo second-order model. Langmuir and Freundlich adsorption models were applied to describe the isotherms and isotherm constants. Equilibrium data agreed very well with the Langmuir model. Thermodynamic studies showed that the adsorption was a spontaneous and endothermic process.
The Fe2O3 nanoparticles activated V2O5 nanotubes were achieved via a hydrolysis method. The TEM and SEM images of the nanotubes indicated that the Fe2O3 nanoparticles with the particle size of about 15 nm were dispers...
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作者：
Kaijie LinGuangze TangYujiang WangXinxin MaKen YukimuraSchool of Materials Science and Engineering
Harbin Institute of TechnologyHarbin 150001China National Key Laboratory of Science and Technology on Precision Hot Processing of MetalsHarbin Institute of TechnologyHarbin 150001China National Key Laboratory for RemanufacturingAcademy of Armored Forces EngineeringBeijing 100072China State Key Lab of Advanced Welding Production TechnologyHarbin Institute of TechnologyHarbin 150001China
Lead free textured K_(0.5)Na_(0.5)NbO_(3) piezoelectric ceramics have been prepared by reactive-templated grain growth method by using NaNbO_(3) with different morphologies as templates. The NaNbO_(3) template particl...
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ISBN:
(纸本)9781457711626
Lead free textured K_(0.5)Na_(0.5)NbO_(3) piezoelectric ceramics have been prepared by reactive-templated grain growth method by using NaNbO_(3) with different morphologies as templates. The NaNbO_(3) template particles with different edge length (10-20 (mu)m) and thickness (0.5-2.5 (mu)m) was synthesized through controlling Bi_(1.5)Na_(x-1.5)Nb_(x)O_(3x+3) precursor's layer numbers x from 2 to 6 by two-step molten salt methods. The crystalline phases and microstructure of textured K_(0.5)Na_(0.5)NbO_(3) were characterized by X-ray diffraction and scanning electron microscopy, respectively. It shows that all the K_(0.5)Na_(0.5)NbO_(3) ceramics are orthorhombic perovskite structure with {001} orientation. By using the template particles with a ratio of edge length to thickness (l/h)(velence)approx10, the textured ceramics with optimized piezoelectric properties was prepared. The results indicate that the enhanced properties of textured ceramics are concerned with the template morphology.
To improve the wear and corrosion properties of AZ91D magnesium alloys,Cu-based amorphous composite coatings were fabricated on AZ91D magnesium alloy by laser cladding using mixed powders of Cu47Ti34Zr11Ni8 and *** we...
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To improve the wear and corrosion properties of AZ91D magnesium alloys,Cu-based amorphous composite coatings were fabricated on AZ91D magnesium alloy by laser cladding using mixed powders of Cu47Ti34Zr11Ni8 and *** wear and corrosion behaviours of the coatings were *** wear resistance of the coatings was evaluated under dry sliding wear condition at room *** corrosion resistance of the coatings was tested in 3.5%(mass fraction) NaCl *** coatings exhibit excellent wear resistance due to the recombined action of amorphous phase and different intermetallic *** main wear mechanisms of the coatings and the AZ91D sample are *** former is abrasive wear and the latter is adhesive *** coatings compared with AZ91D magnesium alloy also exhibit good corrosion resistance because of the presence of the amorphous phase in the coatings.
The gas diffusion layer (GDL) of the proton exchange membrane fuel cell (PEMFC) plays a prominent effect on the water balance inside the fuel cell. A two-dimensional, steady-state, two-phase model for a PEMFC is devel...
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ISBN:
(纸本)9781424480364
The gas diffusion layer (GDL) of the proton exchange membrane fuel cell (PEMFC) plays a prominent effect on the water balance inside the fuel cell. A two-dimensional, steady-state, two-phase model for a PEMFC is developed to investigate the effects of GDL characteristics on the water-protect performance of the fuel cell. Analysis of the water-protect performance of low humidity PEMFC indicates that in the condition of saturated anode inlet humidification and 25% of the cathode inlet humidification, the smaller the porosity, the better the water-protect performance of the fuel cell. The thicker the GDL, the better the water protect capability. The fuel cell with smaller mean aperture has higher water content in the membrane. The stronger hydrophilicity in the GDL plays a certain role of holding the water.
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