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A new generation of bioreactors with integrated six degrees of freedom (6 DOF) aims to mimic more accurately the natural intervertebral disc (IVD) load. We developed and validated in a biological and mechanical study a specimen holder and corresponding ex vivo IVD organ model according to the bioreactor requirements for multiaxial loading and a long-term IVD culture. IVD height changes and cell viability were compared between the 6 DOF model and the standard 1 DOF model throughout the 3 weeks of cyclic compressive loading in the uniaxial bioreactor. Furthermore, the 6 DOF model and holder were loaded for 9 days in the multiaxial bioreactor under development using the same conditions, and the IVDs were evaluated for cell viability. The interface of the IVD model and specimen holder, enhanced with fixation screws onto the bone, was tested in compression, torsion, lateral bending, and tension. Additionally, critical motions such as tension and bending were assessed for a combination of side screws and top screws or side screws and adhesive. The 6 DOF model loaded in the uniaxial bioreactor maintained similar cell viability in the IVD regions as the 1 DOF model. The viability was high after 2 weeks throughout the whole IVD and reduced by more than 30% in the inner annulus fibrous after 3 weeks. Similarly, the IVDs remained highly viabile when cultured in the multiaxial bioreactor. In both models, IVD height changes after loading were in the range of typical physiological conditions. When differently directed motions were applied, the holder-IVD interface remained stable under hyper-physiological loading levels using a side screw approach in compression and torsion and the combination of side and top screws in tension and bending. We thus conclude that the developed holding system is mechanically reliable and biologically compatible for application in a new generation of multiaxial bioreactors., ACS Biomaterials Science & Engineering, 8 (9), ISSN:2373-9878

Owing to the diversity of structure and potential applications in the field of electrics, sensors, and light-emitting diodes, lead halide perovskites have attracted great attention in recent years. Especially those lead halide perovskites with non-centrosymmetric crystal structures usually exhibit nonlinear optical (NLO) characteristics, which may endow them photoelectricity switching functionality. In this work, a lead-based hybrid organic-inorganic perovskite (HOIP) material, trimethyliodomethylammonium lead trichloride (TMIM·PbCl3), is obtained on the basis of tetramethylammonium lead chloride through halogen substitution on the cation part. It shows dual-phase-transition behavior around 345 and 358 K, which is significantly improved. TMIM·PbCl3 crystallizes in the chiral space group, P212121, and shows a well-defined second harmonic generation (SHG) response, and good switching endurance, which makes it an excellent candidate for SHG switching material. This work highlights the importance of halogen substitution for crystal engineering and may pave way for the further exploration of the optoelectronic devices.

Functional assemblies of inorganic nanoparticles (NPs) are widely concerned stems from their collective electromagnetic properties and various application from nanodrugs and bioimaging. In most cases, the superstructures of NPs are prepared with the assistance of templates or external fields. Therefore, how to prepare the functional assemblies of NPs more simply remains a challenge. Here, a free-template assembly strategy for preparing the superstructures of NPs is proposed in our work. In our strategy, we design poly (glycerol monomethacrylate)-b-poly (2-hydroxypropyl methacrylate) (PGMA-b-PHPMA) coated NPs. Then, by using the polymerization-induced self-assembly (PISA), hydrophobic PHPMA blocks occur the phase separation to form the orderly patterns, which is expected to induced NPs to self-assemble into the orderly superstructures. By DPD simulations, we find that the disk, ring, composite superstructures can be obtained by regulating the graft density, verifying that our assembly strategy of NPs is feasible. Even more interesting is that NPs are also orderly distributed on the surface of aggregations to form the orderly NP patterns. Besides that, the thermodynamics, dynamics, and structure details in the self-assembly process of HINPs are shown in our work, providing a new idea and elaborate physical picture for the following preparation of the superstructure of NPs.

In last decades, open-shell organic materials have attracted scientists’ great attention for their new chemical and physical properties, as well as their possible applications in new generation of organic light-emitting diodes (OLEDs), organic field effect transistors (OFETs), organic spintronics and photonics, and so on. In this review, we summarize the recent progress of design and synthesis of open-shell organic magnetic materials. Especially, we will focus on their aggregated states in OFETs, organic conductors and luminescent devices and photoinduced radical materials, with the aim to provide some clue for the further development of novel open-shell organic magnetic materials.

For the first time, POSS and cobalt containing hyperbranched polymer (HP2-Co) was synthesized via a convenient A2+B3 strategy for solid-state pyrolysis to generate magnetoceramics. For comparison, its analogue (HP1-Co) without POSS group was also prepared. After pyrolysis, the ceramic obtained from HP2-Co with POSS groups, had a unique Co@C-SiOx architecture, and its diameter almost remained unchanged with increased pyrolysis temperature, showing good sinter-resistant properties. However, the nanoparticles obtained from HP1-Co sintered seriously with the increased temperature. More importantly, the ceramic yields of HP1-Co and HP2-Co were 82% and 90% respectively, much higher than those of the linear polymers (58-73%). The produced ceramics all showed good magnetic properties, with the saturation magnetization ranged from 40.8-69.0 emu g-1, making them promising candidates for the actual applications.

Single–atom dispersed carbon nitride photocatalysts have been extentively associated with the clean energy conversion, storage and utilization. However, it is still a challenge to elucidate the relationship between the electronic structure of catalyst and their photocatalytic properties. In this work, single atom Ag/C3N4 catalysts have been prepared via pyrolyzing the precipitation of cyanuric acid, AgNO3 and melamine. We observe that their photocatalytic activity increases with increasing the concentration of Ag from 0.32 % to 0.53 %, and subsequently decreases with further increasing the concentration of Ag, which indicates that the concentration of Ag atom can control the performance of the single-atom catalysts. Deep investigations suggest that the concentration of Ag atom can modulate the bottom of conduction band (CB) and the maximum of valence band (VB). The higher the bottom of CB are, the better the performance of catalysts is. In contrast to the bulk carbon nitride, the rate constants for rhodamine B (RhB) and tetracycline (TC) degradation of the optimized single-atom photocatalyst Ag/C3N4 with 0.53 % Ag are enhanced approximately 165.3 and 24.9 times, respectively. Furthermore, the ESR spectrum exhibits that the superoxide radical plays a major role in the photocatalytic process. This work brings a new insight for the structure–property relationship and our strategy provides a guidance for the synthesis of other single-atom photocatalysts.

A large strain (0.33% at 5 kV mm−1) and high temperature stability (strain variation less than 8%) were obtained simultaneously in new BMZ-PZ-PT ternary ceramics by the substitution of BMZ for PZ in PZT ceramics.

Organic room temperature phosphorescent materials have attracted a lot of research interest due to their wide applications. Herein, a series of intramolecular-locked triphenylamine derivatives have been synthesized with adjustable room temperature phosphorescence (RTP) properties, in which the RTP lifetime ranged from 30 to 288 ms and the emission color varied from sky blue to green. These results are mainly related to the substituent effect, which can tune the intramolecular charge transfer and intermolecular interactions, contributing to different intersystem crossing (ISC) processes, and the stability and energy levels of excited triplet states.

Through the introduction of two perylene diimide (PDI) moieties to the triphenylamine (TPA) core, a PDI dimer-based electron transport material has been synthesized with an A (electron acceptor)–D (electron donor)–A structure. It demonstrated a high electron mobility of 8.23 × 10−4 cm2 V−1 s−1 as a thin film and achieved a PCE of 20.07% in perovskite solar cells, higher than that of PC61BM (18.38%) as the standard reference under the same conditions. This is the highest conversion efficiency among various PDI derivatives as ETMs, providing the optimized molecular configuration by combination of twisted core (TPA) and planar peripheral moieties (PDI), as well as matched electronic properties with multiple charge transfer processes.

Many approaches have been explored to tune emission behaviors of organic luminogens. However, precise regulation of distances in dimers is seldom reported. Here, four pyrene derivatives are present...

To simplify the treatment of radioactive wastewater and reduce the secondary pollution, in this work, mesoporous ZrO2/SBA-15 was synthesized and employed for the first time as both the adsorbents and crystalline matrices for efficient enrichment and in-situ immobilization of U in radioactive wastewater. In general, U was efficiently enriched by using the mesoporous ZrO2/SBA-15 and then immobilized into ZrSiO4 ceramics by the followed sintering process. The U-adsorbed ZrO2/SBA-15 was changed to stable ZrSiO4–U ceramics by sintering at 1250–1450 °C for 6 h. The results also provided the evidence that both U(Ⅳ) and (Ⅵ) were incorporated into the crystal structure of ZrSiO4 by replacing Zr(Ⅳ). Furthermore, all the obtained ZrSiO4–U ceramics exhibited good aqueous durability. Given the high adsorption capacity and good aqueous durability, it is expected that the ZrO2/SBA-15 is attractive for actual applications in treatment of U containing radioactive wastewater.

Lithium/sodium metal batteries have attracted enormous attention as promising candidates for high-energy storage devices. However, their practical applications are impeded by the growth of dendrites upon Li/Na plating. Here, we report that holey 2D N-doped TiNb2O7 (N-TNO) nanosheets with high electroactive surface area and large amounts of lithiophilic/sodiophilic sites can effectively regulate Li/Na deposition as an interfacial layer, leading to an excellent cycling stability. The N-TNO interfacial layer enables the Li||Li symmetric cell to sustain stable electrodeposition over 1000 h as well as the Na||Na cell to stably cycle for 2400 h at 1 mA cm-2 and 3 mA h cm-2 with a depth of discharge as high as 50%. The full cells of the Li/Na anodes based on the N-TNO layer paired with the LiFePO4 and NaTi2(PO4)3 cathodes, respectively, show a very stable cycling over 1000 cycles at a negative-to-positive electrode capacity (N/P) ratio up to 3.

Based on the turbine high-temperature combustion gas simulation test platform, the long-term combustion gas environment exposure test of the 2D plain woven SiCf/BN/SiC composites under two combustion conditions was carried out. Uniaxial tensile test, fracture morphology characterization and non-destructive testing analysis revealed the degradation and microstructure evolution of composites after exposure to combustion gas environment. The results show that the degradation of 2D-SiCf/SiC composites after exposure to combustion gas environment is manifested as a decrease in static toughness, and the interphase transition is the mesoscopic cause of the decrease in static toughness of the composite.

Conductive-filler filled polymer composites have exhibited great potential due to the high dielectric constant that can be reached near the percolation threshold, yet the associated high dielectric loss prohibits wide use in practice. Recently, extensive efforts have been devoted to encapsulating conductive fillers with an insulating shell, with the aim to constrain the dielectric loss; but such efforts also significantly reduce dielectric constant. This dilemma raises the question of whether core-shell structured fillers are ultimately beneficial for the dielectric performance of composites, which is less explored. In this study, we investigate polymer nanocomposites containing a series of Al@Al2O3 nanofillers with different shell thicknesses. It shows that the high dielectric constant of percolative composites is contributed by a fast intra-particle polarization and a slow inter-particle polarization. Formation of an insulating shell enables the independent control of the two polarizations, which are otherwise coupled (increasing or decreasing together) in regular percolative composites. By promoting intra-particle polarization and suppressing inter-particle polarization, the core-shell structured nanocomposites can obtain a high dielectric constant and concurrently low dielectric loss, far surpassing the unmodified nanofiller composites. Moreover, the thermal conductivity and high field resistivity are also improved, resulting in a stable and low temperature during operation. This work offers a new paradigm for the design of percolative polymer composite with high dielectric constant and low dielectric loss as well as improved thermomechanical properties.

Regulation of hot spots exhibits excellent potential in many applications including nanolasers, energy harvesting, sensing, and subwavelength imaging. Here, hat-shaped hierarchical nanostructures with different space curvatures have been proposed to enhance hot spots for facilitating surface-enhanced Raman scattering (SERS) and plasmon-driven catalysis applications. These novel nanostructures comprise two layers of metal nanoparticles separated by hat-shaped MoS 2 films. The fabrication of this hybrid structure is based on the thermal annealing and thermal evaporation of self-assembled polystyrene spheres, which are convenient to control the metal particle size and the curvature of hat-shaped nanostructures. Based on the narrow gaps produced by the MoS 2 films and the curvature of space, the constructed platform exhibits superior SERS capability and achieves ultrasensitive detection for toxic molecules. Furthermore, the surface catalytic conversion of p-nitrothiophenol (PNTP) to p, p′-dimercaptobenzene (DMAB) was in situ monitored by the SERS substrate. The mechanism governing this regulation of hot spots is also investigated via theoretical simulations.

A novel desulphurization technology has been put forward using a dispersed in-situ phases induced by an explosive reaction of a composite ball. A composite ball with this function has been designed...

Hierarchically porous metal–organic frameworks (MOFs) not only inherit the merits of MOFs such as high porosity, but they also possess distinct properties such as a broader pore size range and thus...

Spinel oxide materials have been widely used as oxygen evolution catalysts to enhance the photoelectrochemical (PEC) performance of photoelectrodes. Herein, we demonstrate that the water splitting efficiency of a photoanode can be further enhanced by introducing its photothermal effect. Under near-infrared radiation, the temperature of the NiCo2O4/BiVO4 photoanode increases moderately, leading to improved water oxidation kinetics and charge transport simultaneously. With the assistance of the photothermal effect, the obtained photoanode reaches a photocurrent density of 6.20 mA cm-2 at 1.23 V vs reversible hydrogen electrode. A series of spinel-type MCo2O4 oxides (M = Mn, Zn, Cu, and Fe) are deposited on the surface of the BiVO4 photoanode to show similar photothermally enhanced PEC performance. The research discovery provides a way for improving the catalytic activity of photoanode materials with a photothermal effect, which may be applied to various fields of energy conversion, including CO2 reduction, N2 fixation, and pollutant degradation.

The Al–Mg alloy with high Mg addition (Al–9.2Mg–0.8Mn–0.2Zr-0.15Ti, in wt.%) was subjected to different passes (1, 2 and 4) of high strain rate rolling (HSRR), with the total thickness reduction of 72%, the rolling temperature of 400 °C and strain rate of 8.6 s−1. The microstructure evolution was studied by optical microscope (OM), scanning electron microscope (SEM), electron backscattered diffraction (EBSD) and transmission electron microscope (TEM). The alloy that undergoes 2 passes of HSRR exhibits an obvious bimodal grain structure, in which the average grain sizes of the fine dynamic recrystallization (DRX) grains and the coarse non-DRX regions are 6.4 and 47.7 μm, respectively. The high strength ((507±9) MPa) and the large ductility ((24.9±1.3)%) are obtained in the alloy containing the bimodal grain distribution. The discontinuous dynamic recrystallization (DDRX) mechanism is the prominent grain refinement mechanism in the alloy subjected to 2 passes of HSRR.

Among the various anodes, Li3VO4 is a potential intercalation kind anode used in lithium-ion batteries (LIBs) that exhibits safer discharge voltage and higher capacity than graphite, a lower voltage plateau than Li4Ti5O12, and smaller volume difference in the Li+ intercalation/deintercalation process than metals and alloys. However, the comparatively low electronic conductivity, low initial coulombic efficiency (ICE) and serious capacity decay make the Li3VO4 anode unviable when it comes to practical implementation. Therefore, this paper reviews the research progress of Li3VO4 in recent years, mainly including the strategies of developing different synthesis methods to construct unique morphology, through coating, compositing or elemental doping to increase the ICE, electronic conductivity and the cycle constancy. Moreover, the application of Li3VO4 anode materials in other energy storage systems is summarized. Lastly, the development prospect and challenge of Li3VO4 anodes are discussed.

The life of turbine blades often determines the life of the aero-engine, and creep rupture is one of the main fracture forms of turbine blades in high temperature environments. In order to accurate...

High strength and large ductility of existing Mn-containing brass alloys need to be further improved when used as slippers of friction-pair materials, which could be achieved by tuning alloy composition and thermomechanical treatments appropriately. The present work optimized the amount of minor-alloying elements M (M = Mn, Fe, Si) in Cu-Zn alloy via a cluster formula approach and then investigated the microstructural evolution of the designed alloy with different thermomechanical treatments. As-cast alloy ingots were solid-solutioned at 1093 K (820 °C) for 3 h, hot-rolled at 923 ~ 1023 K (650 ~ 750 °C), and then aged at 673 ~ 723 K (400 ~ 450 °C) for 1 ~ 2 h, respectively. It is found that the alloy matrix consists of the main FCC-α phase plus a small amount of BCC-β and M5Si3 phases, among which the M5Si3 exhibits three types of primary, fine, and nano-scaled particles. The mechanical property varies with the thermomechanical treatments due to diverse microstructures (especially the morphology of M5Si3 particles), in which the high strength (σUTS > 580 MPa) and large ductility (δ = 16.3 ~ 29.4%) could be achieved simultaneously in 673 K (400 °C). The optimal matching of high strength and large ductility makes the current alloy more suitable as an alternative slipper material. The strengthening effect was further discussed in light of various strengthening mechanisms, and the calculated strength increment is well consistent with the experimentally measured yield strength.

Red and near‐infrared (NIR) organic light‐emitting diodes (OLED) have gained remarkable interest due to their numerous applications. However, the construction of highly emissive emitters is hampered by the energy‐gap law and aggregation‐caused quenching (ACQ) effect. Whereas, aggregation‐induced emission (AIE) materials could avoid the undesirable ACQ effect and emit bright light in aggregated state, which is one class of the most promising materials to fabricate high‐performance OLED with a high external quantum efficiency and low efficiency roll‐off. This review summarizes recent advances in red and NIR OLED with AIE property, including the traditional fluorescence, thermally activated delayed fluorescence, and hybridized local and charge transfer compounds. Meanwhile, the emphasis attention is paid to the molecular design principles, as well as the molecular structure‐photophysical characteristics. We also briefly further outlook the challenges and perspective of red and NIR AIE luminogens.

In this work, Ni foam supported hierarchical NiCo2O4 nanomaterials are successfully prepared through a hydrothermal process and subsequent calcination process, then the hierarchical NiCo2O4 is converted to hierarchical NiCo2S4 through a hydrothermal anion exchange process. The hierarchical nanomaterials are constructed by a nanorod core and nanoribbons shell. The morphology evolution mechanism of the hierarchical NiCo2O4 is studied by exploratory experiments, the results show that the morphology evolution from nanorod to hierarchical nanostructure undergo a solid–solid process, and the calcination temperature is crucial for the formation of the hierarchical nanostructure. The hierarchical NiCo2O4 and NiCo2S4 nanomaterials are both used as electrocatalysts for methanol oxidation reaction in alkaline electrolyte, and the electrocatalytic activity of the NiCo2S4 is higher than that of the NiCo2O4. Cycling test shows the good stability of the NiCo2S4, and the slight loss of activity during cycling is caused by the surface oxidation of NiCo2S4 in alkaline electrolyte. This work indicate that the hierarchical NiCo2S4 is a promising non-noble metal electrocatalyst for direct methanol fuel cells.

Nanoscale α-Al(FeMn)Si dispersoids in Al alloys play a vital role in improving the recrystallization resistance and mechanical properties of alloys at elevated temperatures. This study investigates the influence of Cu on the precipitation behavior of α-dispersoids in Al–Mg–Si alloys during heat treatment at 500 °C. α-dispersoids in an alloy without Cu addition had rod- or plate-like morphologies. The addition of Cu effectively inhibits the precipitation of α-dispersoids through the formation of fine spherical dispersoids, resulting enhanced mechanical properties of the alloy at elevated temperatures. Evidence from high-resolution transmission electron microscopy demonstrated that the rod- or plate-like structures have simple cubic structures, whereas the spherical α-dispersoids are coherent with the Al matrix along the [101] zone axis of Al, resulting in finer dispersoids, higher thermal stability, and lower coarsening rates. However, its crystal structure requires further investigation.

The purpose of the research is to assess the sound absorption performance (SAP) of acoustic metamaterials made of double-layer Nomex honeycomb structures in which a micro-orifice corresponds to a honeycomb unit. For this purpose, the influences of structural parameters on the SAP of acoustic metamaterials were investigated by using experimental testing and a validated theoretical model. In addition, the sandwich structure was optimized by the genetic algorithm. The research shows that the panel thickness and micro-orifice diameter mainly affect the second resonant frequency and second peak sound absorption coefficient (SAC) of the structure. The unit cell size is found to influence the first and second resonant frequencies and two peaks of the SAC. An extremely low side-length of the honeycomb core decreases the SAP of the structure for low-frequency noise signals. Additionally, the sandwich structure presents a better SAP when the diameter of micro-orifices on the front micro-perforated panel (MPP) exceeds that of the back MPP. The sandwich structure shows better noise reduction performance after the optimization aiming at the noise frequency outside trains.

Despite advances in NiCr + Cr3C2–NiCr coating improving the erosion wear resistance at low impact angles, the deterioration at medium and high impact angles has not been solved for the impeller subjecting to multi–impact angle. Herein the conflict is circumvented by combining the erosion performance of the NiCr and Cr3C2–NiCr under different impact angles and proposing a novel coating structure. First, the NiCr + Cr3C2–NiCr coating specimens with different NiCr content were prepared using the plasma spraying system. Second, the erosion rate of NiCr + Cr3C2–NiCr coatings in relation to the impact angle and the concentration of NiCr was measured by an air jet erosion test system, the microhardness was measured on the polished cross-section, and the erosion morphology was observed by SEM and analysed. Erosion behavior analysis showed that the NiCr + Cr3C2–NiCr coatings exhibited the coupling erosion wear mechanism of high toughness and high hardness, where the dominant characteristic was depending on the concentration of NiCr. Then, a tangential functional gradient coating structure was proposed by combining the excellent erosion wear resistance of ductile and brittle materials at varying impact angles, and a semi-theoretical erosion rate model considering the influence of the NiCr concentration was established based on the deformation wear theory. The erosion rate model was validated by experiments which showed the error was within 9.15%. Consequently, the erosion rate can be regulated on demand along the entire eroded surface, which significantly improves the erosion resistance of cermet at medium and high impact angles, thus prolonging the residual life of remanufactured impeller.

The elastoplastic behaviors of a nickel-based single crystal superalloy at 760 °C, 927 °C and 1100 °C were studied, respectively, after 815 °C/250 MPa lasting for 2000 h, 927 °C/205 MPa lasting for 2000 h and 1100 °C/30 MPa lasting for 1000 h. After 815 °C/250 MPa lasting for 2000 h, the $\gamma '$ phases still maintain the cubic shape, but their size increases compared with the original microstructure. The values of $\sigma _{\mathrm{b}}$ , $\sigma _{0.2}$ , $\delta _{5}$ and $\psi $ increase. The tensile fracture surface is 45° with the [001] direction and the fracture mechanism is octahedral slip. After 927 °C/205 MPa lasting for 2000 h and 1100 °C/30 MPa for 1000 h, N-type plate-like rafting structure formed, and the latter owns a higher degree. The values of $\sigma _{\mathrm{b}}$ and $\sigma _{0.2}$ decrease obviously, while $\delta _{5}$ and $\psi $ basically are unchanged. The mechanism is the mixed fracture of octahedral slip and I-type. The fatigue verification test and simulation further prove the strengthening effect.

The development of adhesive technology is gaining increasing attention in machinery, electronics, aviation, and other fields. However, traditional adhesives are difficult to be peeled and removed after cross-linking and curing due to the limited solubility in common solvents, which causes pollution and damage to the surface of the adherend. In this work, we synthesized random hyperbranched polyamide-amine hot melt adhesives through Michael addition of 1,8-octanediamine and N,N'-methylene diacrylamide (ODA-RHP HMA). Owing to the presence of various polar groups, ODA-RHP HMA exhibited robust lap shear strength to different substrates, including glass (6.6 MPa), ceramics (10.3 MPa), steel (11.5 MPa), and aluminum (11.8 MPa). Due to the hydrogen bonds in ODA-RHP, the HMA demonstrated intrinsic self-healing ability, which can be used repeatedly when being subjected to cyclic heating and cooling. Since ODA-RHP HMA can be swollen or dissolved in ethanol, the adhesives can be easily removed through erasing. In addition, ODA-RHP exhibited aggregation-induced luminescence due to the tertiary amine structure in the molecular structure of ODA-RHP, which can be used in the field of cultural relics restoration.

Biomass-derived carbon materials are often applied in green energy storage systems like supercapacitors due to the abundance, facile access, low cost and nontoxicity. In this work, biomass-derived porous carbon spheres (PCSs) have been prepared by the carbonization and etching of sodium alginate (SA). Using polyacrylic acid (PAA) as a template, N-doped graphene quantum dots (N-GQDs) are grown evenly on the surface of the PCSs, which drastically improves the pseudocapacitive activity and electrical conductivity. The prepared N-GQD/PCS/PAA electrode has a remarkable specific capacitance of 419.3 F g−1 at 1 A g−1. The symmetric supercapacitor assembled with N-GQD/PCS/PAA electrode exhibits a great specific capacitance of 337.5 F g−1 at 0.5 A g−1. Particularly, the device displays an ultrafast charge/discharge rate of 2.5 V s−1, demonstrating excellent rate capability and structural stability. The supercapacitor based on N-GQD/PCS/PAA possesses high energy density of 11.72 W h kg−1 and excellent cycle stability. A high mass loading (9.18 mg cm−2) with the energy density of 8.54 W h kg−1 is also investigated to realize the practical application for the device. In general, a novel biomass-derived carbon electrode modified with highly electrochemical active N-doped graphene quantum dots has been constructed to provide an effective way for high performance energy storage.

High-quality spinel mixed ferrites (M-Fe) are obtained from the electroplating wastewater, which are then used as adsorbents for the removal of elemental mercury (Hg0) in the flue gas to simultaneously realize the purpose of waste resource utilization and pollution control. In the “ferrite process”, through adjusting the dosages of ferrous sulfate (FeSO4·7H2O), the chromium (Cr) in wastewater can be fully recycled to synthesize the M-Fe adsorbents with good crystal morphology and chemical stability, and they can be easily separated by applying a magnetic field. Hg0 removal experiments indicated that the feeding mass ratio of FeSO4·7H2O: Cr6+ and temperatures had great influence on mercury removal efficiency, and the M-Fe adsorbents with FeSO4·7H2O: Cr6+ mass ratio of 100: 1 (M-Fe (100)) had the highest Hg0 removal performance with nearly 100% at 100℃. In addition, M-Fe (100) presented good sulfur resistance, which remained above 90% Hg0 removal efficiency after SO2 injection, and it can recover activity when stopping SO2. The XPS and desorption dynamics analysis showed mercury existed in the form of physically and chemically adsorbed states. Adsorption kinetic studies manifested that surface active sites were the adsorption rate controlling step, and inner active sites played an important role in mercury adsorption process. Mercury equilibrium analysis indicated mercury amount during adsorption and desorption process was approximately identical, manifesting M-Fe (100) was well recyclable magnetic adsorbent.

A large number of pyroshock devices are employed in spacecraft and rockets to realize stage separation and appendage deployment. Release of pyroshock devices induces high-level transient shock responses which tend to cause fatal damages in electronic equipment made of crystals and brittle materials. This paper aims to provide methods to isolate pyroshock and guarantee the safety of such equipment against high-frequency shocks. Firstly, stress wave transmission mechanism in stepped rods is investigated, upon which optimal area rate for shock isolation is achieved. Then, two spacecraft-rocket interface structures for pyroshock isolation, namely isolation hole and interim segment, are proposed. Both numerical simulations and experiments are carried out to validate the two shock isolation strategies. It is revealed that the interim segment structure shows better pyroshock isolation performance at the cost of increasing the weight of launching system whereas isolation hole is an optimal choice to reduce pyroshock response without causing weight increase.

The composition of magnesium alloys is greatly associated with initial deposition behavior of electroless Ni–P coatings. Thus, the initial deposition behavior of electroless Ni–P coatings on ZK60 and ME20 alloys was investigated. The results indicated that differences in the alloy compositions significantly influenced the initial deposition process and the adhesive strength, corrosion resistance, and crystal structure. The initial deposition of coatings on ZK60 and ME20 alloys preferentially occurred on the precipitates. The precipitates in ZK60 alloy had higher chemical activity after HF activation and controlled the initial deposition rate of the coating. The initial deposition rate of the coating on ME20 alloy mainly depended on the density of the MgF2 film formed by HF activation rather than on the precipitates. Owing to differences in the initial deposition process, the coating on ZK60 alloy had higher adhesive strength and better corrosion resistance than that on ME20 alloy. The coatings on ZK60 and ME20 alloys mainly had crystalline structures, and the coating on ME20 alloy had also a slight microcrystalline structure.

To promote the development of enhanced tubes in heat exchangers, forced convection experiments were carried out using R410A in the annular region outside enhanced tubes. Three enhanced tubes were i...

Carbon nanotubes (CNTs) are ideal candidates for beyond-silicon nano-electronics because of their high mobility and low-cost processing. Recently, assembled massively aligned CNTs have emerged as an important platform for semiconductor electronics. However, realizing sophisticated complementary nano-electronics has been challenging due to the p-type nature of carbon nanotubes in air. Fabrication of n-type behavior field effect transistors (FETs) based on assembled aligned CNT arrays is needed for advanced CNT electronics. Here in this paper, we report a scalable process to make n-type behavior FETs based on assembled aligned CNT arrays. Air-stable and high-performance n-type behavior CNT FETs are achieved with high yield by combining the atomic layer deposition dielectric and metal contact engineering. We also systematically studied the contribution of metal contacts and atomic layer deposition passivation in determining the transistor polarity. Based on these experimental results, we report the successful demonstration of complementary metal-oxide-semiconductor inverters with good performance, which paves the way for realizing the promising future of carbon nanotube nano-electronics.

Wettability modification is an effective way in tailoring hotspots in surface Raman scattering (SERS) nowadays. However, due to the theoretical contradiction between hydrophobic and hydrophilic strategies, opposite views are usually put forward in building SERS structures. To realize the integration of hydrophobicity and hydrophilia in the same substrate, a wettability-switchable SERS architecture composed of heterostructured CuO@ZnO@Ag biomimetic nano Setaria (NS) has been designed and prepared in this paper. Experimentally, the structure shows impressive SERS performance under both hydrophobic and hydrophilic states. The limit of detection approaches even to single-molecule level and the lowest relative standard deviation is only ca 9.8%. Finite-different time-domain simulations and experimental analyses were systemically made to unearth the mechanism deep behind. Besides, owing to fine quantifiability, the CuO@ZnO@Ag NS shows promising potential in the detection of trace pesticide and deoxyribonucleic acid. This work provides a new idea for integrating the strategies of ‘concentration’ and ‘decentralization’, endowing SERS structure with wider application, and is also meaningful for other surface sciences.

Refractory high-entropy alloys (RHEAs) with body-centered-cubic (BCC) structure are a new class of alloy materials and have great potential for high temperature applications. The present work investigated the BCC structural stabilities of Ti-Zr-Nb-Hf RHEAs with both first-principles calculations and experimental characterization. The cluster-plus-glue-atom model (cluster model) for the presentation of chemical short-range ordering (CSRO) in solid solutions was applied to construct the model input for the first-principles method, in which the density functional theory was used. Three cluster structural units were considered, [Ti-Hf14]Nb3, [Ti-Zr8Hf6]Nb3, and [Ti-Zr8Hf4Ti2]Nb3. The corresponding alloys were fabricated, and microstructural characterization was performed. The calculated results of the formation energies and free energies of these three alloys indicate that the [Ti-Zr8Hf4Ti2]Nb3 has the highest BCC structural stability due to its lowest formation energy and free energy. It is well consistent with the experimental observation, where the [Ti-Zr8Hf4Ti2]Nb3 alloy exhibits a single BCC structure without any precipitation, while a small amount of α and/or ω phases would precipitate from the BCC matrix in the other alloys. The cluster-model-embedded first-principles method could provide a new approach for accurate calculations.

Conjugated polymers have attracted considerable attention for thermoelectric applications in recent years due to their plentiful resources, diverse structures, mechanical flexibility, and low thermal conductivity. Herein, we demonstrate a new strategy of modulating charge carrier concentration of chemical-doped polymer films by modifying the substrate with self-assembled monolayers (SAMs). The SAM with a trifluoromethyl terminal group is found to accumulate holes in the polymer thin films, while the SAM with an amino terminal group tends to donate electrons to the polymer films. Thermoelectric thin films of conjugated donor-acceptor copolymer exhibit high power factors of 55.6-61.0 μW m-1 K-2 on SAMs with polar terminal groups. These power factors are 49% higher than that on the SAM with the nonpolar terminal group and 3 times higher than that on pristine substrate. The high power factor is ascribed to the modulated charge carrier concentration and improved charge carrier mobility as induced by SAMs.

Polymer membranes typically possess a broad pore-size distribution that leads to much lower selectivity in ion separation when compared to membranes made of crystalline porous materials; however, they are highly desirable because of their easy processability and low cost. Herein, we demonstrate the fabrication of ion-sieving membranes based on a polycarbazole-type conjugated microporous polymer using an easy to scale-up electropolymerization strategy. The membranes exhibited high uniform sub-nanometer pores and a precisely tunable membrane thickness, yielding a high ion-sieving performance with a sub-1 Å size precision. Both experimental results and molecular simulations suggested that the impressive ion-sieving performance of the CMP membranes originates from their uniform and narrow pore-size distribution.

Spinning forming is an effective method for processing thin-walled rotating body parts. The influence of process parameters on the spinning forming limit of materials was studied for the four high-temperature alloys of GH3044, GH3625, GH3536 and GH4169 used in aero-engines. The results can be used as aero-engine high-temperature alloy parts spinning process and provides experimental basis and process guidance. The research results showed that the forming temperature had a significant effect on the spinning forming performance of superalloy materials. When the temperature increased to 800°C and above, the ultimate thinning rate raised 70%. The ultimate thinning rate of GH4169 was higher than the other three materials and GH3044 and GH3536 was at the middle level, GH3625 was relatively low. At the same time, the feed ratio and the corner radius of the rotary wheel had a certain influence on the ultimate thinning rate of different superalloys. The spinning process needs to select reasonable process parameters according to the actual situation when the spinning is applied to manufacture parts.

D406A steel is a medium-carbon low-alloy steel, which has excellent comprehensive mechanical properties. It is widely used in the production of missiles and rocket barrels. In this paper, the spinning forming limit test and the intermediate heat treatment process of ultra-high-strength steel were used to explore the effect of spinning process and heat treatment on the properties of spinning parts. The research results showed that the reduction amount of the material made the material thinning rate approach the limit thinning rate. The final blank wall thickness was reduced from 15 mm to 3.0 mm when the cracking occurred. It was calculated that the material's power spinning limit thinning rate was 80%. The ferrite matrix after spinning showed a streamline distribution characteristic perpendicular to the thinning direction, and the precipitated carbides were uniformly distributed on the surface of the matrix, which had the characteristics of deformation and extension along the streamline. After the heat treatment, the structure of the spinning parts changed continuously. When the structure was quenched and tempered, the martensitic structure can be obtained, and the tempered martensitic structure was smaller. Furthermore a test piece for ultra-high-strength steel spinning technology has been developed, and the solutions discussed for flanging defects in the actual spinning process, and test data for the actual production of ultra-high-strength steel spinning parts accumulated.

Free-standing flexible supercapacitive electrodes have practical application for wearable energy storage devices. In this paper, graphene paper (GP), a flexible electrode substrate, was prepared by one-step reduction of graphene oxide (GO) using HI solution. GP can be used independently as a flexible electrode with specific capacitance of 227 F/g. In order to make up for the shortage of GP specific capacitance storage, polyaniline (PANI) with high specific capacitance and good electrical conductivity was selected to composite with GP by electrochemical polymerization approach. This method to fabricate electrode material by direct electrochemical polymerization avoids the use of conductive binder and organic solvent. Owing to the specific capacitance contribution of PANI and GP, the PANI/GP composites exhibit higher specific capacitance when the polymerization time is 30 s and the polymerization voltage is 0.8 V. At 1 A/g current density, the specific capacitance of composite is up to 759 F/g, which is 3.34 times of neat GP.

In the present work, a new ladle dephosphorization process has been developed using the dispersed in situ phases induced by an explosive reaction of the composite balls with slag forming materials....