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Adaptive temperature control is proposed to increase the nonthermal exposure level of in vitro experiments. By regulating an air temperature to cancel the exposure-induced temperature elevation in cells, the maximum specific absorption rate (SAR) is at least doubled to trigger and characterize nonthermal effects. The air temperature is prescribed by an iteration algorithm to balance the maximum and minimum cell temperature levels while preventing them from exceeding a nonthermal threshold. Adaptive temperature control is applied to a 900-MHz exposure setup based on a TEM cavity. An air temperature regulator was installed to the TEM cavity loaded with cell monolayers in two 35-mm-diameter Petri dishes. SAR and temperature distributions in the culture medium were calculated by the finite-difference time-domain algorithm and validated by | S₁₁| and temperature measurements. Using a properly regulated air temperature, adaptive temperature control suppressed the temperature variances in cells within the 0.1 °C threshold through a 60-min exposure with a 6.10-W/kg average SAR. The SAR is 2.43 times as much as that of conventional temperature control using a stable air temperature. An air temperature regulator for adaptive temperature control is a simple addition to upgrade a conventional exposure setup and increase the exposure level in search of nonthermal effects.

As a candidate material for hydrogen separation, Yb-doped SrCeO3 has attracted increasing attention in recent decades. In the present study, Yb-doped SrCe0.9Yb0.1O3-α ceramics were prepared by the dry pressing and sintering approach, with the microstructure evolution and the micro morphology investigated. It was indicated that the ceramics sintered in air were of a pure perovskite structure, and that the sintering temperature had a significant effect on the growth of ceramic grains. The average grain size increased from 1 ​μm to 10 ​μm with an increase in sintering temperature from 1300 to 1500 ​°C. Further investigation of the thermodynamics and kinetics of grain growth revealed that the grain boundary diffusion was the main driving force of grain growth during solid phase sintering, with a grain growth index of 4 and an activation energy of approximately 61.23 ​kJ ​mol−1. These results illustrate an obvious tendency of grain size growth. By electrochemical workstation with different atmospheres the effects of sintering temperature on the conductivity were characterized in the temperature range of 700–900 ​°C. The electrical conductivities σ of SrCe0.9Yb0.1O3-α ceramics in different atmospheres were as follows: σ(wet hydrogen) ​> ​σ(dry hydrogen) ​> ​σ(dry air) ​> ​σ(wet air). In the test atmosphere containing water and hydrogen the conductivity of protons increased with increasing temperature because of the protons jump between lattices in the form of interstitial hydrogen ions or bare protons.

The epidermal adhesive structure of many animals generates reliable adhesion on their engaged surfaces. However, current bio-inspired adhesion structures are difficult to function well in dry and underwater environments simultaneously. Interestingly, the male Dytiscus lapponicus attaches firmly to the rough shell of the female D. lapponicus in both dry and underwater conditions owing to the adhesive setae of its forelegs, and to the best of our knowledge, designing adhesive structures on multienvironments has never been reported. Here, a D. lapponicus-inspired adhesion structure (DIAS) is proposed and fabricated using double-exposure-fill molding technology accompanied with the material curing shrinkage, in which different structural features could be achieved by varying curing shrinkage ratios, elastic moduli, and back exposure time. The DIAS offered high, reversible, and repeatable strength in dry and underwater conditions with values of 205 and 133 kPa, respectively. By comparing the adhesion properties of different shapes via testing experiments and numerical analysis, a structural feature with an inclination of 15° was found to be optimal. Finally, the potential application of the DIAS in flexible electronic smart skin-attachable devices was demonstrated on a pig skin, paving the way for further bio-inspired adhesive designs for both dry and wet scenarios.

The aim of this study executed on Silicon Nitride (Si3N4) yarn is to examine some bending damage behaviors and fracture mechanisms that occur during the 3D orthogonal fabric forming process. A three point bending experiment device has been developed in order to simulate the Z-binder yarn bending condition. The effects of weft density, fabric thickness, and yarn tension have been studied. The Weibull analysis of the tensile strength show that the bending damage increases with the increase of weft density, fabric thickness, and yarn tension. The resulting bending damage causes a reduction in yarn strength of between 2.5 and 17.2% depending on the bending parameters of yarn. The growth of the fibrillation area also reflects similar trends with tensile strength loss rate. The fibrillation length produced by the yarns is mostly distributed within the range of 0.3 to 0.9 mm. A comparison of the calculation result to experimental data shows the bending fracture probability of filaments inside yarn are less than that of monofilament. The tensile and bending fracture of Si3N4 filaments exhibit typical brittle fracture characteristics.

A large amount of red mud is discharged in the aluminum oxide production process, which contains a variety of valuable metals and is considered as a secondary resource. In order to reveal the mechanism of red mud carbon thermal reduction process, isothermal reduction experiments on carbon-bearing pellets of red mud were investigated with biomass carbon as a reducing agent. In this study, the reduction temperatures were conducted using a microwave stove in the temperature range from 850 to 1250 ℃, and the C/O molar ratio was 1.1. The results show that the reduction process of red mud is governed by a carbon gasification reaction, and the apparent activation energy is 88.44 kJ/mol. The optimum reduction process conditions were established to be 1150 ℃ for 13 min.

A three-step strategy combining solvothermal and liquid phase reduction method had been developed for preparation of magnetic triple-shell hollow structural Fe3O4/FeCo/C (TSH–Fe3O4/FeCo/C) composite microspheres. FeCo was used to enhance electromagnetic (EM) wave absorption in different frequency band and broaden effective absorbing bandwidth, while carbon was used to improve impedance matching. Triple-shell hollow structure was designed to enrich the multiple interfaces to favor the interfacial polarization, increase the multiple reflections and scattering, and provide physicochemical protection to Fe3O4 core from oxidation. The microstructure and morphology of TSH-Fe3O4/FeCo/C composite microspheres were characterized by TEM, XRD and Raman in detail. The results indicated that magnetic Fe3O4 was completely covered by FeCo and carbon via layer by layer. As an EM wave absorber, the maximum reflection loss of TSH-Fe3O4/FeCo/C composite microspheres was up to -37.4 dB due to better normalized characteristic impedance at a thickness of 2.2 mm and the bandwidth less than -10 dB even reached up to 5.9 GHz. The excellent EM wave absorption performance was attributed to the combination of shell materials (Fe3O4, FeCo and carbon) and unique triple-shell hollow structure, which lead to multiple relaxation processes and good impedance matching. Consequently, this work would contribute to the design and preparation of high performance EM wave absorbent with outstanding absorbing property and wider absorption range.

Platinum-tin (Pt-Sn) nanoalloy catalyst supported on Al 2 O 3 was prepared by carbonylation-impregnation method. The catalyst was characterised by means of nitrogen adsorption-desorption, X-ray diffraction and transmission electron microscope, showing the existence of Pt and Sn as Pt 3 Sn alloy. The analysis of particle size distribution revealed that Pt-Sn nanoparticles have high dispersion and narrow particle size distribution with an average diameter of 1.7 ± 0.4 nm. Its catalytic performance toward propane dehydrogenation was also investigated. The propane dehydrogenation reaction showed that the as-prepared Pt-Sn/Al 2 O 3 catalyst exhibited good dehydrogenation performance with the conversion of 27.1% and propylene selectivity of 93.3% after reacting 12 h owing to the close interaction between Pt and Sn components. Coke deposition of the used catalyst was characterised by thermogravimetric and differential thermal analysis method, revealing most of the carbon was on the surface of the support, which meant that more active sites to be accessible to maintain catalytic stability.

A self-healing polycarbonate-based shape memory polyurethane (PCPU) comprising of polycarbonate diol, 4,4′-diphenylmethane diisocyanate (MDI) and 1,4-Butanediol (1,4-BDO) was synthesized. Through a series of shape memory tests, PCPUs showed 100% shape fixation rate, and a shape recovery rate of over 95% within 15 s. PCPUs exhibit excellent mechanical properties compared to common shape memory polymers, such as a tensile strength of up to 38.10 MPa and elongation at break of 616%. Additionally, after being damaged, polyurethane can self-heal within 60 s at 80 °C without any external force, which makes it applicable in many fields.

Vertically-oriented graphene nanowalls (VGNWs) have been successfully synthesized under different experimental conditions (such as flow rate of argon, growth temperature, plasma power as well as deposition time) on copper foils in the reactive methane and argon environment using a capacitively coupled plasma-enhanced horizontal tube furnace deposition system. It is shown that the morphology and structure of VGNWs can be effectively tailored by experimental conditions. Furthermore, the growth mechanism of VGNWs produced in the plasma-based approach has been investigated. The synthesized VGNWs are used as anode materials in Li-ion batteries and the batteries show outstanding cycle efficiency (~99%). The specific capacity of coin-type cells can be improved by adjusting the experimental parameters and reaches 400 mAh g−1 in the first charge-discharge cycle. This work is particularly important for the development of an advanced process for the synthesis and application of carbon-based nanomaterials.

Silicon carbide (SiC) module with high power, high frequency, large current characteristics, has received extensive attention in the new energy vehicles, the new energy power generation, the smart grid and other fields.Electrical characteristics of the 1200V/200A SiC module are analyzed by the finite element simulation method in this paper. Based on the simulation results, a low-inductance and high-reliability SiC module is developed. The parasitic inductance of SiC module is 18.846nH, and the threshold voltage (Vth) is 2.0V, and the change is less than 0.1v before and after aging test. The high temperature gate bias test (HTGB) and high temperature reverse bias test (HTGB) have verified that SiC module still has good stability after a long-time experiment at 150°C and 175°C. After the HTGB, the gate leakage current of SiC module is still below 400nA, and the power consumption increases little. Moreover, after the HTRB, the leakage current of SiC module shows excellent stability, which proves that the SiC module can work at high voltage and high temperature.

Gecko-inspired dry adhesion has attracted much attention for many applications such as soft grippers and wall-climbing robots, which, however, demonstrate stable adhesion on flat surfaces and small adhesion on nonflat surfaces. In practice, geckos' capability of walking upside down on both flat and nonflat surfaces comes from the combined action of adhesive structures for passive adhesion and toe muscles for stiffness modulation. Inspired by this behavior, this study proposes a hierarchal adhesive structure for high and switchable adhesion on nonflat surfaces. The three-layer adhesive consists of a mushroom-shaped structure top layer, stiffness modulation thermoplastic polyurethane (middle layer), and an electrothermal film (bottom layer) that mimics the epidermal adhesive structures, toe muscles, and electromyographic signals, respectively. Through the tunable structural stiffness controlled by adjusting the voltage, the adhesive force can be increased by 1 or 2 orders of magnitude compared to the conventional adhesive structures and further used for attachment and detachment functions. The gecko-inspired soft gripper is successfully tested as a pick-up and drop-down system for transporting a surface with different features, which has great application potential in industrial lines and daily life.

With the combination of the passive adhesion generated by micro/nano-structures at their feet and the active mechanical stimulus of their toe muscles, geckos can stably walk on vertical walls and horizontal ceilings. Inspired by such stimuli-responsive systems in nature, an active adhesive soft gripper stimulated by low voltage (usually ≤6 V), consisting of a passive mushroom-like adhesive structure and an electrically active liquid crystal elastomer working as toe muscles, is proposed in this study. Through voltage on/off switching, reversible deformation can be generated for switchable adhesion, where high adhesion can be achieved under the action of a preload force accompanied by a 0 V voltage and low adhesion can be obtained under an exerted voltage. This gecko-inspired soft gripper was tested and found to be successful as a transport device for gripping/releasing objects with different features, such as a glass ball, a sample bottle, and a steel weight. To the best of our knowledge, the present study is the first to propose an electrically active gecko-inspired soft gripper for transferring objects with different surfaces by the control of low voltage, processing great application potential in industrial lines and daily life and providing a novel perspective on soft gripper design.

The flow resistance in granular mass flows can be due to frictional contacts or collisional interactions between particles. For a constant number of particles, the transition from a frictional to a collisional regime is expected to depend on flow velocity and is associated with an increase of volume and a decrease of bulk density, an effect termed dilation. The relation between velocity, dilation and flow resistance is not well understood. Here we present results of steady, non-uniform flows of ceramic beads (d = 4 mm) in a rotating drum, a setup allowing observations and averaging of parameters measured over an extended period of time. We systematically varied flow mass between 12.3 and 49 kg and flow velocity between 0.2 and 1.2 m/s, while continuously measuring basal normal stress and flow depth. Flow resistance was assessed by calculating average bulk shear stress from torque measurements at the axis of the drum as well as from the deviation of the center of mass from the vertical. Additionally, the flows were captured by high-speed video recordings through the transparent side wall. We find bulk densities at the deepest section of the flow decreasing from 1430 kg/m³ at low velocities to 1370 kg/m³ at the highest velocity for the largest flow mass. At the same time flow resistance increased linearly. When the flow mass was reduced, also bulk density decreased, indicating the importance of overburden pressure for dilation. Video recordings revealed that shear is concentrated in depth zones of lower volume fraction. Our results shall contribute to a better understanding of the transition from a frictional to a collisional flow regime and may help to assess the importance of dilation for gravitational mass flows.

In this work, we develop a simple customized radio-frequency plasma-enhanced horizontal tube furnace deposition system to directly grow high-quality ZnO nanorod arrays on zinc films and investigate their application as an antireflective layer in n+pp+ monocrystalline silicon (c-Si) solar cells. Field emission scanning electron microscope, X-ray diffractometer, and transmission electron microscope studies reveal that ZnO nanorod arrays feature a perfect crystalline wurtzite structure and grow preferentially along [0001] direction. The antireflective performance of ZnO nanorod arrays is confirmed by Fresnel coefficient matrix method and MATLAB software calculation. Furthermore, PC1D simulation demonstrates that the photovoltaic property for c-Si solar cells of the pyramid-textured front surface using ZnO nanorod arrays as an antireflective layer is much better than that for the other three types of c-Si solar cells (i.e., c-Si solar cells of the pyramid-textured front surface without using any antireflective layer, c-Si solar cells of the planar front surface using ZnO nanorod arrays as an antireflective layer, as well as c-Si solar cells of the planar front surface without using any antireflective layer). In particular, the photovoltaic conversion efficiency of 20.23% has been achieved for c-Si solar cells of the pyramid-textured front surface using ZnO nanorod arrays as an antireflective layer. This work is highly relevant to the development of an advanced process for the realization of high-efficiency, low-cost, and stable solar cells.

Water pollution is a serious problem around the world. It causes the lack of clean drinking water and brings risks to human health. Membrane technology has become a competitive candidate to treat the contaminated wastewater due to its high separation efficiency and low energy consumption. In this review, we introduce the recent development of several kinds of bioinspired separation membranes, involving the membrane design and applications. We emphasize the multi-phase liquid separation membranes inspired from nature with special wettability applied for oil/water separation, organic liquids mixture separation, and emulsion separation. After separating multi-phase liquids using these membranes, small molecule pollutants still exist in single-phase liquid. Therefore, we also expand the scope to small molecule-scale separation membranes, such as the nacre-like graphene oxide separation membrane and other nanofiltration membranes. Summary and outlook concerning the future development of separation membranes are also introduced briefly.

Surface modification of chemically-inert hexagonal boron nitride (h-BN) to reduce its interfacial thermal resistance remains problematic, thereby hindering its application in thermal conductive composites. Here, poly(glycidyl methacrylate) (PGMA) chains were grafted onto the surface of h-BN by using a simple free radical polymerization. The prepared PGMA grafted h-BN (h-BN-PGMA) was incorporated into epoxy (EP) to enhance the thermal conductivity of EP composites. Adding 3, 9 or 15 vol% of h-BN-PGMA into EP leads to 60%, 203% or 505% increase s in thermal conductivity, respectively. Meanwhile, the surface modification of h-BN is benefit to enhance the compatibility between the fillers and EP matrix, which reduces the apparent viscosity of composite materials. Furthermore, compared with EP/h-BN, EP/h-BN-PGMA composites with the same filler-loading exhibit higher storage modulus and glass transition temperature. Additionally, the dielectric constant of the composites hardly depends on the testing frequency while the dielectric loss maintained at a very low level.

Research on electrical properties of the compensated silicon is very crucial for understanding the doping layer and compensated substrates of solar cells. Regarding the fact that there are still inadequate experimental data of carrier mobility on the n-type compensated silicon, hence in this paper, both majority electron and minority hole mobilities measured on the n-type compensated solar-grade silicon substrates are presented. Prediction models of carrier mobility are essential for material characterization and device (e.g. solar cells) simulation. However, as prediction models of carrier mobility are commonly established based on the uncompensated silicon, large deviations of carrier mobility have been observed on the compensated silicon. In this work, the standard Klaassen’s model and optimized model for the compensated silicon by Schindler et al. are reviewed and compared to measured carrier mobilities. Moreover, the factors that lead to deviations of Klaassen’s model on the n-type compensated silicon are critically discussed, and then we propose an optimized model for prediction of carrier mobility in the compensated silicon. This model can also be extended to both majority and minority carrier mobilities in p- and n-type compensated silicon and fits well with previous published data as well as carrier mobility data presented here. In addition, evolutions of majority electron and minority hole mobilities as crystal grows are also simulated for n-type compensated Czochralski silicon which agrees well with our measured results.

Zinc oxide nanoparticles were synthesized using bovine serum albumin as stabilizers through a facile one-pot strategy in aqueous media. The morphology and crystal phase of the zinc oxide nanoparticles were determined by transmission electron microscopy, X-ray diffractograms, and Fourier transform infrared spectroscopy. The synthesized ZnO nanoparticles exhibited strong absorption and photoluminescence properties in the visible wavelength region based on the fluorescence and UV-visible spectroscopy. Based on the results, the zinc oxide nanoparticles could effectively degrade the organic dyes through the mediation of the hydroxyl radical under visible light irradiation. Furthermore, the zinc oxide nanoparticles show good recycling stability during the photocatalytic experiments. These results suggested that the as-prepared zinc oxide nanoparticles might be used as a potential photocatalyst to efficiently treat the organic pollutants.

Perovskite-type oxides have been considered to be an effective oxygen carrier for producing O 2 /CO 2 for oxy-fuel combustion application, which is a promising technique for carbon capture and storage. However, the main problem of common perovskite-type oxygen carriers is their relatively low oxygen desorption capacity at atmospheric pressure. Therefore, it is important to develop new oxygen carriers and enhance the reaction pressure to achieve high desorption capacity. In this study, a series of A/B-site substitution Ba 1 − x Sr x Co 1 − y Fe y O 3 − δ (x = 0, 0.5, 1; y = 0, 0.2, 1) perovskites were synthesized by sol-gel method, and the oxygen desorption performance of them was investigated in pressurized fixed bed. The perovskite samples were characterized using X-ray diffraction (XRD), X-ray fluorescence (XRF), X-ray photoelectron spectroscopy (XPS) and Transmission electron microscopy (TEM) measurements. The effect of reaction pressure, temperature and flow rate on the oxygen desorption performance were investigated in details. The results indicated that all of the Ba 1 − x Sr x Co 1 − y Fe y O 3 − δ perovskites showed an obvious improvement on oxygen desorption capacity at pressurized conditions. Besides, BaCoO 3 − δ showed the best oxygen desorption performance among the Ba 1 − x Sr x Co 1 − y Fe y O 3 − δ (x = 0, 0.5, 1; y = 0, 0.2, 1) perovskites. Oxygen desorption amounts of BaCoO 3 − δ increased by 57.2% and 62.7% under 2 MPa and 3 MPa conditions respectively, comparing to that of it under atmospheric pressure at 850 °C. The optimal temperature and WHSV for BaCoO 3 − δ are 850 °C and 176.78 h −1 . XRF and XRD results showed that the elemental contents of perovskites remained after reactions and the crystal structure of perovskites could recover after cyclic process under high pressure calcination. XPS results showed the evolution of oxygen species during oxygen desorption process.

Palladium/kieselguhr (Pd/K) composites with 57 wt.% of Pd were prepared by an improved dipping and thermal decomposition method and heated at elevated temperature to reduce breakdown during hydrogenation-dehydrogenation cycles. The hydrogen absorption kinetic properties of the samples heated at different temperatures were tested under the condition of 20 °C with 100 kPa hydrogen pressure. The 1300 °C heated Pd/K composites were repeated up to 4010 absorption and desorption cycles at temperature ranges between −40 °C and 200 °C. The results show that the phase structure, hydrogen absorption capacity and hydrogen saturation time of the Pd/K were not affected by the change of heat-treated temperatures. And after heat treatment at 1300 °C, the Pd/K particles were strengthened and fraction of larger than 80 mesh were as high as 93.4%.

In this work, an Er2O3/Cr2O3 composite coatings on 316L stainless steel were prepared by metalorganic chemical vapor deposition (MOCVD). Effect of Cr2O3 layer on the microstructure, mechanical properties and deuterium permeation properties of Er2O3 coating was investigated. It was found grain sizes of the coatings enlarged with increasing the thickness of Cr2O3 layer. The Er2O3/Cr2O3 (80 nm) composite coating showed larger adhesion force value 9.2 N than the Er2O3 coating. The Cr2O3 layer adding could significantly enhance the deuterium permeation inhibition property of the coatings. The single-layer Er2O3 coating exhibited the minimum reduction in deuterium permeability, and the permeation reduction factor (PRF) values were in the range of 95–146 at 823–973 K. The maximum reduction in deuterium permeability was obtained from the Er2O3/Cr2O3 (80 nm) composite coating, and the PRF values were in the range of 463–206 at 823–973 K. With further increasing thickness of the Cr2O3 layer to 120 nm, the hydrogen permeation inhibition performance of the composite coating lower instead. Furthermore, apparent delamination of coating was illustrated on the single-layer Er2O3 coating after the permeation measurement, and this might be the main reason for the transformation to diffusion limiting process.

From physical point of view, the “0, 1” read/write operation of ferroelectric memory is based on the polarization switching of ferroelectric memory. Therefore, the reliability of device relies directly on the stability of polarization switching behavior. The polarization behaviors of HfO2-based ferroelectric thin films subjected to bipolar cyclic electric field often exhibit wake-up, fatigue and split-up of transient switching current. These unstable switching properties seriously restrict the practical application of this new-type ferroelectric material in memory devices. It therefore becomes the critical task to explore the mechanism behind the complex evolution of polarization switching and find out possible approaches to optimizing the stability. However, it will be extremely difficult to accomplish the task by the traditional characterization methods. First-order reversal curve (FORC) diagram is regarded as “fingerprint identification” in the study of hysteresis systems, and has been used successfully to analyze the characteristic parameters of magnetic materials. The FORC diagram can intuitively determine the type, size and domain status of magnetic particles from distribution of both coercive field and interaction field. Moreover, it is also found that the FORC diagram is sensitive to measuring temperature. In this work, first, the Preisach model and implementation method of the FORC diagram are introduced. Then using Keithley 4200-SCS equipped with a remote pulse measurement unit, 60 FORCs are recorded for Si-doped HfO2 ferroelectric thin films experiencing different external field loading histories. By the mathematical treatment, switching density distributions determined by FORC measurements are obtained to explore the evolution of coercive field and bias field. The FORC diagram of pristine film contains three distribution regions with different bias fields, which merge into one distribution with an almost zero bias field after 104 wake-up cycles. Two oppositely biased regions can be observed after 2 × 109 sub-cycling treatments. Surprisingly, the bias fields nearly vanish again after 104 wake-up cycles. The main change of bias field instead of coercive field indicates that the migration of oxygen vacancies is likely to be the dominant mechanism behind the complex polarization switching behavior for HfO2-based ferroelectric thin films.

The inhibition effect of 2-(quinolin-2-yl)quinazolin-4(3H)-one on the corrosion of Q235 steel in 1 mol/L HCl solution was investigated by means of potentiodynamic polarization curves, electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM)/energy dispersive X-ray spectroscopy (EDX), Fourier-transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) methods. The experimental results reveal the 2-(quinolin-2-yl)quinazolin-4(3H)-one has a good inhibiting effect on corrosion of Q235 steel in 1 mol/L HCl solution. Polarization studies show that the 2-(quinolin-2-yl)quinazolin-4(3H)-one is a mixed-type inhibitor. The adsorption of the inhibitor on steel surface obeys Langmuir adsorption isotherm and contains both physisorption and chemisorption. On the basis of surface analysis and characterization, the formation and characteristic of an adsorption-related protective inhibitor film on the steel surface have been verified. Finally, the mechanisms of corrosion and protection of the Q235 steel by the quinoline derivative inhibitor have been proposed.

Despite considerable advances in tissue engineering over the past two decades, solutions to some crucial problems remain elusive. Vascularization is one of the most important factors that greatly influence the function of scaffolds. Many research studies have focused on the construction of a vascular-like network with prevascularization structure. Sacrificial materials are widely used to build perfusable vascular-like architectures, but most of these fabricated scaffolds only have a 2D plane-connected network. The fabrication of three-dimensional perfusable branched networks remains an urgent issue. In this work, we developed a novel sacrificial molding technique for fabricating biocompatible scaffolds with a three-dimensional perfusable branched network. Here, 3D-printed poly(vinyl alcohol) (PVA) filament was used as the sacrificial material. The fused PVA was deposited on the surface of a cylinder to create the 3D branched solid network. Gelatin was used to embed the solid network. Then, the PVA mold was dissolved after curing the hydrogel. The obtained architecture shows good perfusability. Cell experiment results indicated that human umbilical vein endothelial cells (HUVECs) successfully attached to the surface of the branched channel and maintained high viability after a few days in culture. In order to prevent deformation of the channel, paraffin was coated on the surface of the printed structure, and hydroxyapatite (HA) was added to gelatin. In conclusion, we demonstrate a novel strategy toward the engineering of prevasculature thick tissues through the integration of the fused PVA filament deposit. This approach has great potential in solving the issue of three-dimensional perfusable branched networks and opens the way to clinical applications.

In this work, Y 2 O 3 /Cr 2 O 3 composite coatings were deposited on 316 L stainless steel by metal organic chemical vapour deposition (MOCVD). Effect of Cr 2 O 3 layer on the microstructure, mechanical properties and deuterium permeation properties of Y 2 O 3 coating was investigated. In order to investigate the evolution of the microstructure in working environment, Y 2 O 3 /Cr 2 O 3 composite coating was high temperature annealed in argon or hydrogen atmosphere. After annealing at 973 K in hydrogen atmosphere, the (222) diffraction peak became weak whereas the (400) diffraction was strengthened. The adhesion force reduced from 9.7 N of the Y 2 O 3 /Cr 2 O 3 composite coating annealed in argon atmosphere to 8.6 N of that annealed in hydrogen atmosphere. It was inferred that hydrogen atoms invasion might be responsible for this mechanical property difference. The deuterium permeation inhibition performance of the coatings was examined by deuterium permeation measurement. After annealed at 973 K in argon atmosphere, the single-layer Y 2 O 3 coating exhibited the minimum reduction in deuterium permeability, and the permeation reduction factor (PRF) values were in the range of around 435–272 at 873–973 K. The maximum reduction in deuterium permeability was obtained from the Y 2 O 3 /Cr 2 O 3 composite coating with Cr 2 O 3 layer thickness of 120 nm, and the PRF values were in the range of around 612–432 at 873–973 K. With further increasing thickness of the Cr 2 O 3 layer to 160 nm, the hydrogen permeation inhibition performance of the composite coating lowered instead. Furthermore, the Y 2 O 3 /Cr 2 O 3 composite coating annealed in argon atmosphere exhibited better deuterium permeation inhibition performance than that annealed in hydrogen atmosphere. After adding the Cr 2 O 3 layer, the Y 2 O 3 /Cr 2 O 3 coating exhibited stable permeation fluxes at each driving pressure, while spikes of the permeation flux were observed for the single-layer Y 2 O 3 coating.

In order to accelerate the sedimentation of super-large-scale argillized ultrafine tailings with bad features such as low settling velocity, muddy overflow water, and large flocculant dosage, a fly-ash-based magnetic coagulant (FAMC) was used in a dynamic experimental device. To obtain the best possible combination of the impact factors (magnetic intensity, FAMC dosage, flocculant dosage, and feed speed) for minimum overflow turbidity, a response surface methodology test coupled with a four-factor five-level central composite design was conducted. The synergy mechanism of FAMC and flocculant was analyzed based on the potential measurement and scanning electron microscopy. The results show that the flocculant dosage, overflow turbidity, and solid content can be reduced by 50%, 90%, and 80%, while the handling capacity per unit and efficiency of backfill and dry stacking can be promoted by 20%, 17%, and 13%, respectively, with a magnetic intensity of 0.3 T, FAMC dosage of 200 mL/t, flocculant dosage of 30 g/t, and feed speed of 0.6 t/(m2(h). Therefore, synergy of FAMC and flocculant has obvious efficiency in saving energy and protecting the environment by allowing 70×106 t/a of argillized ultrafine tailings slurry to be disposed safely and efficiently with a cost saving of more than 53×106 Yuan/a, which gives it great promise for use in domestic and foreign mines.

In this work, Y2O3 coatings were deposited on 316L stainless steel substrate by metal organic chemical vapor deposition (MOCVD), followed by annealing at 700 °C in argon or hydrogen atmosphere. The effect of annealing atmosphere on the deuterium permeation inhibition properties of Y2O3 coatings was investigated. The coating was characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and scanning electron microscope (SEM). The hydrogen permeation inhibition performance of coatings was investigated by deuterium permeation measurement. When post-annealed in hydrogen atmosphere, a FeCr2O4 layer formed at the interface as a result of element diffusion, leading to obvious increase of the permeation current from the first measurement cycle to the second. The deuterium permeation reduction factor (PRF) values of the coating were in the range of 412–102 at 500°C–700 °C in the first measurement cycle. However, the PRF values decreased to 276–43 at 500°C–700 °C in the second measurement cycle. The coating post-annealed in hydrogen atmosphere exhibited lower permeation inhibition performance than that post-annealed in argon atmosphere, which might be ascribed to the cracks and holes presented in the coating.

The effect of Cr2O3 layer on the deuterium permeation properties of Y2O3/Cr2O3 composite coating was investigated. Composite coating was prepared on 316L stainless steel by metal organic chemical vapor deposition (MOCVD). The Cr2O3 layer contributed to the completely decomposition of the original precursor with no presence of unreacted or partially reacted precursor molecules. The deuterium permeation inhibition performance of the coatings was examined by deuterium permeation measurement. The Y2O3/Cr2O3 composite coating exhibited better deuterium inhibition performance than the single-layer Y2O3 coating with the same thickness. The permeation reduction factor (PRF) value of the Y2O3/Cr2O3 composite coating was 167–477 at temperatures of 823–973 K, while the PRF value of the single-layer Y2O3 coating was 96–292 at 823–973 K. Moreover, the Y2O3/Cr2O3 composite coating exhibited a stable permeation flux, while a spike of the permeation flux was observed for the single-layer Y2O3 coating. Therefore, the Cr2O3 layer could enhance deuterium permeation inhibition properties significantly.

As one of the biomanufacturing technologies, 3D bioprinting is becoming one effective way to solve the issues in tissue engineered constructs. In order to produce 3D cell-laden scaffolds to overcome the main technological barrier in cell distribution and nutrient supply and better mimic the in vivo cellular environment, hydrogel fibers were used to deposit in 3D bioprinting system and obtain the 3D cell-laden hydrogel structures. In the present work, we investigate the effects of flow rates on the dimensions of hydrogel fibers. The volume of fluid model by the computational fluid dynamics software package FLUENT 6.3.26 is applied to obtain the appropriate flow rates to produce hydrogel fibers. Different flow pattern in the coaxial model is obtained. In addition, a coaxial nozzle was used to fabricate hydrogel fibers under various flow rates to know its’ effects on the dimension of hydrogel fibers.

The effect of microstructure on the deuterium permeation inhibition properties of Er 2 O 3 coatings was investigated. Coatings were prepared by metal organic chemical vapor deposition (MOCVD) followed by annealing at 700 °C or 800 °C. The coating annealed at 700 °C exhibited a more compact structure than the as-deposited coating and the coating annealed at 800 °C. The hydrogen permeation inhibition performance of coatings was investigated by deuterium permeation measurement. The most compact 700°C-prepared coating also exhibited the best permeation inhibition performance. Furthermore, large cracks and holes appeared on the coating annealed at 800 °C after the permeation measurement, suggesting too high annealing temperature could result in more structural defects, leading to poorer mechanical integrity and inhibition performance. X-ray photoelectron spectroscopic analysis indicated that the oxygen/erbium ratio of the coating annealed at 700 °C corresponded closely to the stoichiometric ratio.

Alginate tubular fiber has been successfully prepared via coaxial fluid crosslink mode, which is potentially used for the construction of vascularized tissue engineering scaffolds (VTES). However, its elastic and smooth surface is negative for the adhesion of fibers. In this study, the gel fractions were controlled in a novel way of two-step crosslink process in order to meet the needs of each processing link. Based on such consideration, an appropriate formulation was selected to direct write single fiber, which ensured the tubular structure with enough gel portion as well as adhesion between fibers with the reserved sol. Finally, the integrity of the scaffolds had a further development within the 2nd crosslink bath process, which would help to solve the question of poor shear resistance for hydrogel scaffolds.

To date, almost all reported graphene nanowalls (GNWs)/Si solar cells are fabricated through the direct deposition of GNWs on the silicon wafer. In this work, we report a polymer-free transfer method of GNWs grown on the copper foil for the fabrication of GNWs/Si solar cells. This allows us to further improve the photovoltaic performance of the solar cells by means of interface engineering. An optimized photovoltaic conversion efficiency (PCE) of the as-fabricated GNWs/Si solar cell can reach up to 4.99%. Furthermore, the PCE of the device is further improved by introducing the spiro-OMeTAD thin film as an interface layer, which serves as an electron-blocking and hole-transporting layer through tuning the band structure of the solar cells. Without any chemical doping and anti-reflecting coating, the maximum PCE of 8.27% has been achieved for the GNWs/spiro-OMeTAD/Si solar cell through optimizing the dopant content and the thickness of the spiro-OMeTAD thin film. We believe that our study indicates a new route for the fabrication of high-efficiency, low-cost GNWs/Si Schottky heterojunction solar cells without the need for chemical doping of the GNWs.

A new spectral selective coating using Ag as metal reflector has been optimized based on the optical properties of TiAlON and AlON single layer. The absorptance is 95.32% and the emittance is 9.65% at 550 °C calculated by integrating spectral reflectance in the spectral region of 2.5–25 μm wavelength. The microstructure and thermal stability of Ag/TiAlONM/TiAlOND/AlON spectral selective coating was characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), Auger electron spectroscopy (AES) and high-resolution transmission electron microscopy (HRTEM), respectively. It shows that the thickness of TiAlONM, TiAlOND, and AlON layer is 68 nm, 27 nm and 35 nm, respectively. The solar absorptance has reduced by 2.9% and the thermal emittance has increased by 3.2% after annealed at 600 °C for 168 h. TiAlON which is stable up to 700 °C in vacuum, could act as a barrier layer for inhabiting diffusion of Ag element into absorb layer. Unlike the single layer, spectral selective coating gets crystallized after annealed, which is attributed to the internal stress of the coating. Thus, Ag/TiAlONM/TiAlOND/AlON spectral selective coating can be excellent candidate for high temperature applications.

A series of Ag films were deposited on stainless steel by magnetron sputtering as an infrared reflective layer in solar selective absorbing coating, while their micro-morphologies and phase structure were characterized by SEM and XRD. The effects of different thickness, substrate roughness and deposition temperature on both spectrum reflectance and emittance are investigated. The minimum thermal emittance of 0.6% at 25 °C can be obtained with thickness of 120 nm and it is not affected by deposition temperature below 100 °C. The spectrum reflectance tends to decrease with an increase of the substrate roughness and deposition temperature. Depositing the TiAlONM/TiAlOND/AlON layer on the optimized Ag film, the emittance of the SSAC at 400 °C is only 5.8%, which meets the optical requirements for the IR-reflector.

For the lift correction design of the shear wall structure, there are two schemes to choose the new underpinning structure jacking and the direct jacking under the wall. Combined with a practical project, this paper puts forward the way of opening jacking joint mainly, supplemented by underpinning structure jacking, and points out that the new underpinning structure jacking method should be designed and checked according to the space truss theory. Direct jacking with holes under the wall should meet the requirements of jacking bearing capacity, local bearing capacity and axial pressure ratio. Through the comparative analysis of the two schemes, it is considered that the opening direct jacking method should be given priority, so as to provide reference for similar projects.

Gas counter pressure (GCP) technology can increase the pressure of melt before flowing effectively. Therefore, it has a potential to reduce shrinkage ratio and improve dimensional accuracy of conventional injection molding part. The effect of different process parameters on the shrinkage ratio of molded parts was studied by means of S/N ratio and ANOVA. The results showed that GCP pressure was the most important factor affecting the shrinkage ratio of molded parts, followed by packing time, injection pressure, mold temperature, melt temperature and packing pressure. Meanwhile, the most optimal combination of process parameters and 1.27% shrinkage ratio of parts were obtained. Finally, the influence of different process parameters on the shrinkage ratio of molded parts was also analyzed.

Deep oil and gas reservoirs enjoy great opulence in resources, and yet the ultra-deep burial, high temperature, high pressure and natural fractures in reservoirs bring great difficulties to propped fracturing. Given the challenge of propped fracturing in deep reservoirs, a new cost saving and high density fracturing fluid system was developed, of which the performance was evaluated and formulation was optimized, and with this fracturing fluid system, wells that cannot be treated before, can now be effectively stimulated. The advanced fracturing fluid system has been applied to eight layers in five wells, which all proved to be successful and effective, with remarkable reservoir stimulation efficacy. The post-production in the formation testing grew twice of the pre-fracturing production, and two wells were seen gas production exceeding one million cubic meters. The advanced fracturing fluid system greatly expands the well depth range of exploration and development, and lays a solid technical foundation for implementation of propped fracturing in deep reservoirs.

Novel Z-Scheme CuBi2O4/&beta, Bi2O3 composite photocatalysts with different mass ratios and calcination temperatures were firstly synthesized by the hydrothermal method following a temperature-programmed process. The morphology, crystal structure, and light absorption properties of the as-prepared samples were systematically characterized, and the composites exhibited enhanced photocatalytic activity toward diclofenac sodium (DS) degradation compared with CuBi2O4 and &beta, Bi2O3 under visible light irradiation. The optimal photocatalytic efficiency of the composite, achieved at the mass ratio of CuBi2O4 and &beta, Bi2O3 of 1:2.25 and the calcination temperature of 600 &deg, C is 92.17%. After the seventh recycling of the composite, the degradation of DS can still reach 82.95%. The enhanced photocatalytic activity of CuBi2O4/&beta, Bi2O3 is closely related to OH&bull, h+ and O2&bull, &minus, and the photocatalytic mechanism of CuBi2O4/&beta, Bi2O3 can be explained by the Z-Scheme theory.

A conversion efficiency of 20.23% of heterojunction with intrinsic thin layer (HIT) solar cell on 156 mm × 156 mm metallurgical Si wafer has been obtained. Applying AFORS-HET software simulation, HIT solar cell with metallurgical Si was investigated with regard to impurity concentration, compensation level, and their impacts on cell performance. It is known that a small amount of impurity in metallurgical Si materials is not harmful to solar cell properties.

A YAG continue-wave laser has been used to refine the surface of silicon wafers in this study. During laser scanning, the irradiated region of the surface of the wafer experienced melting and subsequent recrystallization, which results in a redistribution of metal impurities in the molten pool along the depth direction. Cross-sectional micrographs of irradiated wafers have a clear boundary, which confirms the process of recrystallization, and the depth of molten region depends on the scanning parameters and the size of wafer. Secondary ion mass spectrometry measurements have been carried out to characterize the concentration of metal impurities. After redistribution of metal impurities, a final relative purity region was formed close to the surface. SIMS measurements demonstrate that the metal impurity concentration of the purity region has significantly reduced. The mechanism of the redistribution process of metal impurities in the molten pool has been qualitatively analyzed. All of the experimental results support that the CW laser scanning technology can effectively refine the specific surfaces of silicon wafers, and this technology has a great potential in the field of solar cells.

Biological three-dimensional printing is a promising field of research, and offers potential for overcoming the main technological barriers to the fabrication of three-dimensional vascularized tissues and organs. One of the major methods to fabricate vascular-like networks that can support perfusion of nutrients and oxygen is the printing of hollow hydrogel fibers. In the present work, we investigate the effects of operating conditions on the dimensions of hollow hydrogel fibers and the interaction mechanism of coaxial fluids. The continuity equation and momentum equation integrated with the reaction–diffusion model established by Kim et al. [1] are used to establish a mathematical model of the fabrication of hollow fibers from coaxial fluids. The volume of fluid model by the computational fluid dynamics software package FLUENT 6.3.26 is applied to quantitatively simulate the flow pattern details. A stable liquid/liquid jetting co-laminar flow in the coaxial nozzle is obtained. In order to verify the validity of the simulation model, a coaxial nozzle is used to fabricate hollow hydrogel fibers under various flow rates. The results from simulations and experiments are consistent with each other.

The clinical applications of tissue engineering are still limited by the lack of a functional vascular supply in tissue-engineered constructs. In order to improve the pre-vascularization of tissue-engineered scaffold during in vitro culture, in this study, based on three-dimensional (3D) printing technology, using the crosslinking effect of coaxial fluids (sodium alginate and CaCl2) to prepare vessel-like hollow gel fibers, then layer by layer overlapping into 3D scaffold. The biological 3D printing platform was successfully developed and a coaxial nozzle module was introduced to generate a CaCl2-in-Alginate coaxial microfluidic. The inner core diameters of the prepared hollow gel fibers were 220~380 micrometers. In addition, the influence of materials concentration and dispensing rates on hollow fiber dimension were investigated, the cell-encapsulated in the printed hollow fibers was realized and the viability of endothelial cells (ECs) was studied with Laser scanning confocal microscopy (LSCM) and Live-Dead cell staining. The 3D scaffold built by hollow fibers could improve the phenomenon of diffusion constrain and enhance the survival rate of those ECs growing at a greater depth in the construct. This study provides a new theoretical basis for the vascularization of bone scaffold.

Bi 2 O 3 on the Mg/Al layered double hydroxide (Bi 2 O 3 /LDH) was prepared by impregnation technique, its calcined product was reconstructed and modified with Pd(II) (Pd(II)-Bi 2 O 3 /RLDH), which was demonstrated as an efficient visible-light photocatalyst. XRD confirmed that the phase of loaded Bi 2 O 3 transformed from α-Bi 2 O 3 to β-Bi 2 O 3 at 773 K calcination temperature. N 2 -adsorption/desorption, SEM and TEM displayed that the resulting Pd(II)-Bi 2 O 3 /RLDH composite possess high crystallinity, hierarchical structure as well as large specific surface area. EDX and ICP-AES were used to investigate the type and content of the elements in Pd(II)-Bi 2 O 3 /RLDH. UV–vis DRS confirmed that Pd(II)-Bi 2 O 3 /RLDH, with a low band gap of ∼2.19 eV, has a broad absorption in visible light region. The as-prepared Pd(II)-Bi 2 O 3 /RLDH displayed significant photocatalytic activity for the degradation of methylene blue (MB) under visible-light irradiation. Factors such as calcination temperature, LDH content and Pd (II) content were studied, which may affect the photodegradation of MB. The stability of the photocatalysts was comfirmed using reclaimed Pd(II)-Bi 2 O 3 /RLDH in four successive runs, demonstrating its great potential application in the field of photocatalysis. With the supports of the characterization analysis and experimental results, a reasonable mechanism of photocatalytic degradation of MB by Pd(II)-Bi 2 O 3 /RLDH was proposed.

In this work, an Al2O3/Cr2O3 composite film on 316L stainless steel was prepared by metal-organic chemical vapor deposition (MOCVD). The template effect of α-Cr2O3 interlayer on α-Al2O3 growth in the Al2O3 layer is examined. It is found that α-Cr2O3 is formed in the composite film, however no crystallized alumina is detected. The composite film consists of amorphous Al2O3 and α-Cr2O3. Thus, the α-Cr2O3 template does not stimulate the nucleation of α-Al2O3. Furthermore, the deuterium permeation behavior of the composite film is examined. It is found that the deuterium permeation suppression property of the Al2O3/Cr2O3 composite film is not simply the addition of the deuterium permeation suppression properties of amorphous Al2O3 and α-Cr2O3 single films. The composite film exhibits much lower permeability than the single films of Al2O3 and Cr2O3 with similar thickness. The permeability reduction factors (PRF) were increased by the Al2O3/Cr2O3 composite film to 230–544 at temperatures of 823–973 K, while the PRF values of the Al2O3 film and the Cr2O3 film are 95–247 and 24–117 at temperatures of 823–973 K. Therefore, the Al2O3/Cr2O3 composite film can significantly enhance the deuterium permeation suppression property.

Yttrium oxide coatings were deposited on 316L substrate using metal organic chemical vapor deposition (MOCVD) technique with yttrium β-diketonates organometallic Y(tmhd)3 as precursor. The different microstructures were obtained by annealing coatings at 700 °C or as-deposited. The film was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), infrared spectroscopy and X-ray photoelectron spectroscopy (XPS). The hydrogen permeation inhibition performance of films was investigated by deuterium permeation experiment. The crystalline structure of the coatings depended on the post-anneal; the crystallite size of the coating increases and the surface exhibits compact surface morphology for the coatings post-annealed at 700 °C. The coating post-annealed at 700 °C has the correct oxygen/yttrium ratio corresponding well to the stoichiometric Y2O3, while some concentrations of carbon and hydrogen impurities were found in the as-deposited coating. The impurities are present in the form of unreacted or partially reacted precursor molecules due to the incomplete decomposition of the original precursor. The deuterium permeability of the coating improved obviously after post-anneal and was around 240–410 times less than that of the 316L stainless steel, which means efficient inhibition to deuterium permeation.

Deuterium permeation measurement s and microstructure analysis on yttrium oxide coating deposited by metal organic chemical vapor deposition (MOCVD) were studied. The composition and microstructure of the coating can be adjusted by tuning sublimation temperature and deposition temperature. It is found that the coating sublimated at 150 °C and deposited at 600 °C possesses compact surface morphology with no pinhole s or cracking was observed. Moreover, the oxygen/yttrium ratio corresponding well to the stoichiometric Y 2 O 3 was observed by X-ray photoelectron spectroscopy (XPS) with no moving of Y3d binding energy doublet peaks and O1s binding energy peak at different depth throughout the coating. The permeation properties of coating s depended much on the microstructure. The coating sublimated at 150 °C and deposited at 600 °C exhibits the best permeability property with PRF value s 412–244 at 873–973 K. However, a permeability drop, especially for the 800 °C deposited coating was observed. It was believed that the obvious increase of pinhole and crack density caused the increase of deuterium permeability. Furthermore, the existence of (Fe,Cr) 2 O 3 , forming a grid structure in the natural oxide layer of stainless steel, increases its hydrogen permeability.