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Herein, in-situ Zr 3 [Al(Si)] 4 C 6 -based composites with 10–40 vol% ZrB 2 –SiC (2-to-1 molar ratio) were prepared by hot-pressing sintering at 1850 °C. The simultaneously incorporated ZrB 2 –SiC constitute multicomponent reinforcements and has a synergistic effect on the matrix, which improves the sinterability, mechanical properties, and oxidation resistance of materials. It is found that both of the toughness and strength increase first and then decrease with the increasing content of ZrB 2 –SiC, while the hardness increases near linearly. Zr 3 [Al(Si)] 4 C 6 –ZrB 2 –SiC shows high strength (623 MPa), toughness (7.59 MPa m1/2), and hardness (18.6 GPa), which can be ascribed to the synergistic mechanisms of the binary ZrB 2 –SiC including fine-grained strengthening, particle reinforcement, intragranular microstructure, grain's pull-out and crack bridging, etc. In addition, the oxidation kinetics of as-prepared materials follow the parabolic law, and the composite shows a low oxidation rate of 0.87 × 10−5 kg2 m−4 s−1 when oxidized at 1400 °C. [ABSTRACT FROM AUTHOR]

Pt-SnO 2 catalysts supported on modified carbon fibers were prepared by an electrospinning method with polyacrylonitrile (PAN) as the carrier and polyvinylidene fluoride (PVDF) as the pore-forming agent. The physical-chemical property and catalytic performance of the as-synthesized composites were characterized by XRD, SEM, BET, Chronoamperometry and AC impedance. The results showed that the porous structure in the carbon fibers was formed after calcination at 800 °C in the presence of PVDF. When the weight ratio of PAN/PVDF was 1:0.8, the porous carbon fibers had the largest surface area of 374.85 m2 g−1, which was 3.3 times of carbon fibers prepared without PVDF. The in-situ formed porous structure in carbon fibers can provide more active sites for the catalytic reaction. Therefore, the porous carbon fiber supported Pt-SnO 2 catalysts exhibited the best catalytic performance with the ethanol oxidation peak current value of 140.14 mA cm−2 and the electrochemical active area up to 54.296 m2 g−1. DEFC performance showed that the best potential was 0.7 V and the maximum of power density was 18.1 mW cm−2 when the oxygen flow rate and the temperature were 100 mL min−1 and 80 °C, respectively. Pt-SnO 2 catalysts supported on modified carbon fibers were prepared by an electrospinning method with polyacrylonitrile (PAN) as the carrier and polyvinylidene fluoride (PVDF) as the pore-forming agent. When the weight ratio of PAN/PVDF was 1:0.8, the porous carbon fibers had the largest surface area of 374.85 m2 g−1. The porous carbon fiber supported Pt-SnO 2 catalysts exhibited the best catalytic performance with the ethanol oxidation peak current value of 140.14 mA cm−2 and the electrochemical active area up to 54.296 m2 g−1. Image 1 • Porous carbon fibers were prepared by one-step electrospinning method. • PVDF was used as the pore-forming reagent during the carbonization process. • Porous C/Pt-SnO 2 exhibited the best catalytic activity for the ethanol oxidation. [ABSTRACT FROM AUTHOR]

Plasma Enhanced Chemical Vapor Deposition (PECVD) SiNx films deposited at the substrate temperatures from 20 to 180 °C and at the RF powers from 10 to 30 W were investigated. It is found that the films'' properties such as density, refractive index, composition and bonding configuration are varied with the substrate temperature and RF power. The moisture resistant ability of the deposited SiNx films was investigated by the water vapor permeation (WVP) measurement. Even at the low substrate temperature such as 50 °C, the moisture resistance of SiNx films keeps quite good. Our results can be applied in Organic Light Emitting Devices (OLED) packaging effectively. [Copyright &y& Elsevier]

• Nanocrystals were assembled in sodium alginate to prepare flexible sensors. • The emission and mechanical properties depended on the co-assembly ratio. • The assembled membrane emitted varied light under strain and humid stimuli. Uniaxially assembling cellulose nanocrystals (CNCs) can induce strong solid-state emission based on optical inelastic scattering, whereas the CNC assembly membranes are not flexible enough for further applications. Thus, we introduced CNC into flexible sodium alginate (SA) and further controlled the assembly structure of CNC to increase the membrane toughness and maintain the emission properties. The results indicated that the stretchability increased from 0.027 % to 37 % when 33–37% when 33 % SA was introduced. The assembly achirality was controlled by tuning CNC concentration in suspension, and the co-assembly could further control the wavelength of the assembly-induced emission from 420 nm to 440 nm. Furthermore, the improved stretchability made assembly membrane an optical sensor, whose excitation wavelength blue-shifted about 30 nm under a 30 % strain. The emission of the co-assembly membrane could also respond to humidity, and this cellulose-based material should have great potential in biosensor and wearable devices. [ABSTRACT FROM AUTHOR]

Electromagnetic (EM) data obtained by using an m-sequence source is typically segmented with an m-sequence cycle, and the random noise is suppressed by stacking the earth impulse responses recovered from each data segment. However, the stack cannot suppress the powerline noise, which is normally several orders of magnitude greater than the random noise. In this paper, the powerline noise reduction with different data lengths were compared by numerical simulation; the results show that there is always an optimal data length, not a single cycle but several cycles that can achieve maximum powerline noise suppression. The concept of an identification system was proposed and the identified earth impulse response is obtained by measuring the system output with the input of the voltage response. The optimal data length was summarized in two cases by analyzing the identification system with different data lengths. Coding frequency optimization was proposed to shorten the optimal data length to increase the stacking times. Finally, the validity of the theory described in this paper was verified by field data processing. Different from the traditional subtraction method and notch filter, the powerline suppression method presented here does not need a noise record or filter design; the powerline noise is suppressed accompanied by the identification processing without any additional workload; the simple and practical method provides a new insight into the powerline noise reduction. With this method, the utilization of field data is improved and the anti-noise performance of the m-sequence is also fully exploited. [ABSTRACT FROM AUTHOR]

To provide a basis for the high-temperature oxidation of ultra-high temperature ceramics (UHTCs), the oxidation behavior of Zr 3 [Al(Si)] 4 C 6 and a novel Zr 3 [Al(Si)] 4 C 6 -ZrB 2 -SiC composite at 1500 °C were investigated for the first time. From the calculation results, the oxidation kinetics of the two specimens follow the oxidation dynamic parabolic law. Zr 3 [Al(Si)] 4 C 6 exhibited a thinner oxide scale and lower oxidation rate than those of the composite under the same conditions. The oxide scale of Zr 3 [Al(Si)] 4 C 6 exhibited a two-layer structure, while that of the composite exhibited a three-layer structure. Owing to the volatilization of B 2 O 3 and the active oxidation of SiC, a porous oxide layer formed in the oxide scale of the composite, resulting in the degradation of its oxidation performance. Furthermore, the cracks and defects in the oxide scale of the composite indicate that the reliability of the oxide scale was poor. The results support the service temperature of the obtained ceramics. [ABSTRACT FROM AUTHOR]

A flat arid unmanned Gobi in northwest Gansu, China, has been recognized as a good location for a planned spent-fuel reprocessing plant site. To better assess its applicability and safety as a proposed site, it is important to understand the composition and characteristics of the local vadose zone. Laboratory tests were carried out to analyze the basic properties of the soil in the unsaturated layer, such as particle size, structure, chemical composition and mineralogical characteristics. The permeability coefficients at different depths were measured by three methods, including the single ring, double ring, and inverse auger methods. Four groups of probes were buried at depths of 0.2–4 m in the vadose zone to detect changes in matrix suction with water content in the dehydration state and to determine the field soil-water characteristics curve. Based on the measured hydrological and geological parameters, the migration of intermediate-level nuclides H-3, Co-60, and Cs-137 from the vadose zone into groundwater was simulated by HYDRUS-1D under different rainfall intensities. The simulation results showed that the vadose zone in the study area has a strong retention effect, in which the Co-60 and Cs-137 nuclides were retained in the vadose zone during the 1000-year simulation period. The radioactivity and distribution coefficients of the nuclides were the main factors affecting the time to reach the pollution standard at the groundwater level on a short time scale. Rainfall significantly increased nuclide migration speed on a large time scale. Finally, two engineering protection measures derived from weakening the driving force and increasing the migration path were proposed and were effective in a numerical simulation. • Vadose zone in a planned spent fuel reprocessing plant site was investigated. • Soil-water characteristic curve was fitted by field test and filter paper method. • Migration of H-3, Co-60, and Cs-137 in the vadose zone was simulated. [ABSTRACT FROM AUTHOR]

Titanium carbide (TiC) fibers are attractive functional materials that find application in the areas of energy, environment, and biology. Herein, a simple precursor route is designed to prepare TiC fibers by means of electrospinning. The precursor is prepared by adding polyvinylpyrrolidone (PVP) to as-synthesized polytitanoxane (PTO), and the synthesis process, structure, and thermal behavior of the resulting TiC fibers are analyzed. Smooth and continuous precursor fibers with a uniform diameter of ~1.22 μm are obtained after the electrospinning of the precursor. With increase in the preparation temperature, the phase composition of the fibers evolves into TiC from TiC x O y via pyrolysis and carbothermal reduction. Chemical-state analysis results show that the surface of as-prepared TiC fibers exhibits very weak oxidation, thus leading to TiO 2 and TiC x O y formation. In addition, all the prepared fibers show uniform morphologies without adhesion. With the proposed approach, continuous TiC fibers with a diameter of ~0.55 μm can be obtained. [ABSTRACT FROM AUTHOR]

Biomimetic surfaces with the hierarchical structure consisting of multilayered pore microstructures and TiO 2 hollow nanostructures were fabricated by combining a modified breath figure method and a dip-coating technique. For creating the hierarchical structure, acetylacetone-chelated and non-chelated tetrabutyltitanates in the coating solution were used as the titanium sources to produce the titanium-based gel film and hollowly nanostructured TiO 2 , respectively. Meanwhile, the smaller and larger water droplets condensed in sequence during the breath figure process were used as the templates to generate the hollow structures and pore structures, respectively. The parameters of the hierarchical structures, including the pore diameter, pore density and the output of TiO 2 hollow nanostructures, were conveniently tailored by varying the volume ratio of tetrabutyltitanate to acetylacetone in the coating solution. The as-prepared titanium-based gel films on glass substrates can be transformed into the corresponding anatase TiO 2 films by a subsequent annealing process. The synthesized films were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction pattern, thermogravimetry and Fourier transform infrared spectroscopy. The designed hierarchical structure effectively endows the films with the rose-like superhydrophobic behavior, and the introduction of TiO 2 hollow nanostructures within multilayered pores plays an important role in the superhydrophobic property and the strong adhesion to a water droplet. • Introduction of chemical reaction in breath figure method. • Two-step condensation of water droplets. • Combination of pore microstructure and hollow nanostructure. • Tailorable parameters of the hierarchical structures. [ABSTRACT FROM AUTHOR]

A series of Dy3+ and Tm3+ co-doped Li 2 Gd 4 (WO 4) 7 (LGW) single-phase white phosphors were fast synthesized by microwave assisted solid-state reaction method. Single-ion doped LGW:Dy3+ and LGW:Tm3+ phosphors were synthesized to obtain quenching concentrations. The ideal white light (0.33, 0.33) locates on the straight line that connects the Commission Internationale de L'Eclairage (CIE) coordinates of LGW:Dy3+ and LGW:Tm3+. Therefore, Dy3+ and Tm3+ were selected to co-dope LGW to realize white light emission. By changing Dy3+ concentration, white light was obtained under the excitation wavelengths of 356 nm and 363 nm. Luminescence decay curves and the emission spectra of the co-doped phosphors were characterized to verify the existence of energy transfer between Tm3+ and Dy3+ in this single-phase phosphor. Energy transfer efficiency and energy transfer mechanism were investigated in detail. This fast synthesized single-phase white phosphor LGW:Dy3+, Tm3+ is a good candidate for the white light emitting diodes. [ABSTRACT FROM AUTHOR]

• Minimum Squared Error Method based on Modal Analysis for Source Location. • The microfiber coupler sensors are used to detect acoustic emission signals. • This method reduce the dependence of locating results on frequency selection. • This method automate the locating process of contour threshold modal analysis. • Both linear and planar location were performed on an aluminium thin plate. This study focuses on an improved modal analysis method to the source location using a microfiber coupler sensor (MFCS). This method uses the Minimum Squared Error(MSE) to reduce the dependence of locating results on frequency selection and automate the locating process of contour threshold modal analysis. First, the secondary enclosed package method of MFCS was studied to ensure that the signal detected by this sensor meets the requirements of the contour threshold modal analysis and can extend the MFCS working life as well. The MSE method was then presented detailed. Second, the directionality experiment of the MFCS was performed to determine the best layout method for sensors in planar localization. The planar source localization method with both two sensors and three sensors are then introduced. Last, both linear and planar location experiments were performed on an aluminium thin plate. The results indicate that the sensor packaged by cuboid glass tube is more suitable for practical ultrasonic testing; the location process is automated by valid contour extraction and initial frequency selection, and the linear error using this method is effectively reduced as well; the best arrangement of the sensor is to place the sensor at the corner of the planar, and the angle between the sensor and the horizontal line is 45°; compared with two sensors, the planar localization with three sensors provides a more accurate and high repeatability results. This study proved that the combination of the MFCS and the MSE method is quite feasible and can be applied to the planar localization in plate-like structures effectively. [ABSTRACT FROM AUTHOR]

Abstract A series of BaLaMgSb 1- x Nb x O 6 :Eu3+ double perovskite red phosphors was successfully obtained. X-ray diffraction ans Rietveld refinement analyses were conducted to determine the phase information and the detailed structure parameters. The coordinate variations of both La3+/Eu3+ and Sb5+/Nb5+ were discussed to elucidate the influence of B-site ion doping on the lattice variation. Luminescence properties, excitation and emission spectra, were presented to show the advantages of doping with Nb5+ ion. Ultraviolet-vis diffuse reflectance spectra were performed to reveal the reason for the decreased emission intensity under the charge transfer band excitation. Moreover, band gap energy was estimated to clarify the relationship between the increased intensity (λex = 395 and 465 nm) and Nb5+ concentration. Intensity ratios of I(615)/I(590) were performed to show the symmetry variation of the lattice. Thermal quenching property was also investigated and the quenching mechanism was discussed in detail based on the ionization process. [ABSTRACT FROM AUTHOR]

(Ba 1- x Ln 2 x /3 )(Co 0.7 Mg 0.3 ) 1/3 Nb 2/3 O 3 (0.01 ≤ x ≤ 0.04, Ln=La, Nd) ceramics were synthesized by solid-state reaction process and their sintering behavior, microstructure and microwave dielectric properties were investigated in this paper. The X-ray diffraction results show that all the samples exhibit a single peroskite phase except for the Nd-substituted compositions with x > 0.02. The sinterability and grains distribution are improved by the La-substitution. Though the long range ordering degrees on B-site are similar in the Ln-substituted compositions, the size of ordered domains observed by HRTEM images are quite different. Compared with the Nd-subsituted compositions, the higher Q × f values in the La-substituted compositions are mainly attributed to the better densification and ordered domain structure with lower energy barriers. Both ε r and τ f values increase slightly with the increase of Ln-substitution. A good combination of microwave dielectric properties was obtained in the La-substituted composition with x = 0.01: ε r = 32.5, Q × f = 79812 GHz, τ f = 4 ppm/°C. [ABSTRACT FROM AUTHOR]

Evaluation of the local scour at a uniform bridge pier has become an important issue for hydraulic engineers. However, it is still difficult to accurately predict the local scour depth at the bridge pier using empirical formulae. Reasons underlying this could be the limitation of the statistical fitting technique and the complexity of flow and scouring mechanisms. In this study, a target-modified attention neural network called masked attention neural network (MATN) has been proposed to estimate the flow-induced local scour depth at the uniform cylindrical bridge pier. The experimental data used for training, validation and testing in the MATN model are obtained from several published references. Two laboratory experiments were also carried out to demonstrate the reliability and performance of the MATN model. This study shows that MATN model yields reliable agreements with the historical and test data sets by using small but important data within 10% of equilibrium scour time, which is better than those obtained from empirical scour depth formulae and two classical neural network models Back Propagation Neural Network and Recurrent Neural Network. It further indicates that the MATN model can realize a fast and cost-effective scour depth prediction based on short period of initial scour process. • A Masked Attention Neural Network (MATN) was designed to predict the temporal scour depth at a uniform bridge pier. • Through capturing long-range dependencies and interactions of scour depth data, MATN predicts the scour depth reliably. • Observed data within 10% equilibrium scour time are enough to train the model. [ABSTRACT FROM AUTHOR]

Four different phase compositions of calcium phosphate (CaP) particles were prepared via a solution combustion method. X-ray diffraction (XRD) and Rietveld analysis results revealed that the variations in the nominal Ca/P (molar) ratios were found to provide a favorable control in the different proportions of CaP materials. Bovine serum albumin (BSA) was used as a model protein to study the loading and release behavior. The release profile indicated that the BSA release rates depended on the phase compositions of the CaP particles, and showed an order of TCP-BSA > BCP-1-BSA > BCP-2-BSA > HA-BSA. The results suggested that the BSA protein release rate can be controlled by varying the phase compositions of CaP carriers. Moreover, the release process involved two stages: firstly surface diffusion via ion exchange and secondly intraparticle diffusion. [ABSTRACT FROM AUTHOR]

The solution combustion method was used to prepare single phase hydroxyapatite (HA), β-tricalcium phosphate (β-TCP) and biphasic calcium phosphates (BCP). The powder samples were synthesized with a Ca/P molar ratio from 1.45 to 1.67, and annealed at different temperatures. These samples have been characterized by XRD and FTIR. The amount and lattice parameters of each phase in these samples were refined by the MAUD program. The results of Rietveld refinement show that a single phase HA is obtained with Ca/P ratio of 1.67 and annealing at 1150°C for 3h, β-TCP is isolated with a Ca/P ratio of 1.5 after annealing at 950°C and remains stable up to 1050°C. Apart from above two extremes a whole range of BCP can be prepared with a favorable control of Ca/P ratios and annealing temperatures. [ABSTRACT FROM AUTHOR]

Ternary Si–C–N films were produced in a radiofrequency plasma enhanced chemical vapor deposition reactor applying the precursor gases silane, methane, and nitrogen or ammonia. The properties of the films to function as external moisture barrier layers were investigated with emphasis on the correlation of deposition parameters and moisture permeation rate. The moisture penetration through the films has been investigated in water vapor permeation experiments and capacitance measurements from humidity sensors in plastic packages. The moisture resistance is mainly influenced by the stress in the films with best results for those samples exhibiting no or low compressive stress. [Copyright &y& Elsevier]

Considerable effort has been devoted to the efficient degradation of pharmaceuticals and personal care products (PPCPs), while the chemical energy in these processes has been widely overlooked. In this study, we demonstrated the simultaneous hydrogen production and ibuprofen degradation through heterogeneous photocatalysis. By anchoring Au nanoparticles (NPs) on the (101) surface of sheaf-like TiO 2 mesocrystals with [001] orientation, efficient charge separation is achieved, which is essential for the photocatalytic redox reactions. XPS analysis showed that the binding energies of Ti 2p and O 1s indicated no shift after Au addition. Peaks observed at 81.8 and 85.5 eV due to Au 4f 7/2 and Au 4f 5/2 of metallic gold on the surface of Au/meso-TiO 2 , confirmed the formation of Au NPs. The as-synthesized anatase TiO 2 mesocrystals are composed of small nanocrystals with a size of 8 nm and exhibit the uniform sheaf-like morphology along [001] orientation. As expected, the 1 wt% Au/TiO 2 mesocrystals shows the largest photocurrent density, highest H 2 -evolution rate, and fastest photodegradation rate of ibuprofen under simulated sunlight irradiation among all the studied catalyst. Furthermore, the effect of solution pH, common anions (Cl−, NO 3 −, and SO 4 2−) and cations (Na+, K+, and Ca2+) on photocatalytic H 2 evolution and degradation of ibuprofen were individually investigated and discussed. A mechanism for the simultaneous photocatalytic hydrogen generation and degradation of ibuprofen has also been proposed. This work opens up new opportunities for the development of energy efficient techniques for PPCPs degradation. Image 1 • Au nanoparticles were anchored on the (101) surface of sheaf-like TiO 2 mesocrystal. • [001] growth and exposure of (101) surface enhanced the spatial charge separation. • High activity for simultaneous photocatalytic PPCPs treatment and H 2 evolution. [ABSTRACT FROM AUTHOR]

• AgI modified g-C 3 N 4 is prepared by an in-situ decomposition-thermal polymerization. • AgI modified g-C 3 N 4 shows nitrogen vacancy, reduced band gap, and efficient charge transfer. • AgI modified g-C 3 N 4 exhibits enhanced photocatalytic nitrogen fixation performance. It is of great significance to develop N 2 photo-fixation under mild conditions with solar energy as the only energy input. Herein, we report a convenient in-situ decomposition-thermal polymerization method to obtain AgI modified g-C 3 N 4 heterogeneous catalyst with nitrogen vacancy for enhanced photocatalytic nitrogen fixation. The 2.5% AgI loaded g-C 3 N 4 composite exhibited the best performance for N 2 photo-fixation (150 mg/L/h/g Cat) due to the existence of nitrogen defects, reduced band gap, enhanced separation efficiency of the photo-generated charge carriers and the strong reduction power of more negative conduction band. Furthermore, a feasible reaction mechanism was proposed for the photocatalytic nitrogen fixation process. [ABSTRACT FROM AUTHOR]

• Ag/B-doped g-C 3 N 4 was prepared by an in-situ decomposition-thermal polymerization. • Ag/B-doped g-C 3 N 4 showed reduced band gap and efficient charge separation. • Ag/B-doped g-C 3 N 4 exhibited enhanced photocatalytic nitrogen fixation performance. Photocatalytic nitrogen fixation is considered as a promising strategy for ammonia production. In this study, non-metallic boron and noble metal silver modified graphitic carbon nitride were prepared by a direct in-situ decomposition-thermal polymerization method with dicyandiamide, boric acid and silver nitrate as the precursors. It was shown that Ag/B-doped g-C 3 N 4 composites with optimal mass ratio exhibited improved photocatalytic ammonia production under simulated sunlight illumination by a factor of 5.5 and 1.5 times compared with the pristine g-C 3 N 4 and B-doped g-C 3 N 4 , respectively. The superior photocatalytic property was attributed to the decreased band gap and formation of mesopores after boron doping, which enlarged the specific surface area and created abundant reactive sites on the g-C 3 N 4 nanosheets. In addition, the loaded silver nanoparticles greatly inhibited the recombination of photogenerated charge carriers through heterojunction interface. This work provided new deep insights into the reasonable structure of g-C 3 N 4 composite system for photocatalytic nitrogen fixation reactions. [ABSTRACT FROM AUTHOR]

• I-doped g-C 3 N 4 were synthesized by an in-situ decomposition-thermal polymerization. • I-doped g-C 3 N 4 showed reduced band gap and extended PL lifetime. • I-doped g-C 3 N 4 exhibited enhanced photocatalytic nitrogen fixation performance. Photocatalytic nitrogen fixation has attracted great attention recently due to the mild condition with solar energy as the only energy input. In this work, the iodine-doped g-C 3 N 4 with carbon vacancies has been successfully synthesized via a one-step thermal-decomposition method. The results showed that the band gap of g-C 3 N 4 decreased and the average PL lifetime of g-C 3 N 4 increased after iodine doping. This demonstrated the expansion of light responsive range and the high separation efficiency of the photo-generated charge carriers in iodine-doped g-C 3 N 4. The g-C 3 N 4 with 10 wt% iodine doping exhibited excellent performance and well stability for the photocatalytic nitrogen fixation under simulated sunlight irradiation within 3 h (200.8 mg/L/g cat), which is 2.8 times as high as that of bulk g-C 3 N 4 , owing to the reduced band gap, existence of carbon vacancies and enhanced separation efficiency of the photo-generated charge carriers. A feasible mechanism was proposed for photoinduced charge separation and nitrogen photofixation over iodine-doped g-C 3 N 4. [ABSTRACT FROM AUTHOR]