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In this work, Ag/Bi5O7I nanocomposite was prepared and firstly applied in piezo/photocatalytic reduction of N2 to NH3 and methyl orange (MO) degradation. Bi5O7I was synthesized via a hydrothermal-calcination method and shows nanorods morphology. Ag nanoparticles (NPs) were photo deposited on the Bi5O7I nanorods as electron trappers to improve the spatial separation of charge carriers, which was confirmed via XPS, TEM, and electronic chemical analyses. The catalytic test indicates that Bi5O7I presents the piezoelectric-like behavior, while the loading of Ag NPs can strengthen the character. Under ultrasonic vibration, the optimal Ag/Bi5O7I presents high efficiency in MO degradation. The degradation rate is determined to be 0.033 min−1, which is 4.7 folds faster than that of Bi5O7I. The Ag/Bi5O7I also presents a high performance in piezocatalytic N2 fixation. The piezocatalytic NH3 generation rate reaches 65.4 μmol L−1 g−1 h−1 with water as a hole scavenger. The addition of methanol can hasten the piezoelectric catalytic reaction. Interestingly, when ultrasonic vibration and light irradiation simultaneously act on the Ag/Bi5O7I catalyst, higher performance in NH3 generation and MO degradation is observed. However, due to the weak adhesion of Ag NPs, some Ag NPs would fall off from the Bi5O7I surface under long-term ultrasonic vibration, which would greatly reduce the piezoelectric catalytic performance. This result indicates that a strong binding force is required when preparing the piezoelectric composite catalyst. The current work provides new insights for the development of highly efficient catalysts that can use multiple energies.

This article presents a three-switch (3S) boost converter with hysteresis current control applied in MiniLED panels. It uses only three power switches to achieve high conversion ratio (=7.5) and low inductor current (20% lower than conventional boost converters). Meanwhile, the charging time of the flying capacitor will increase as the duty cycle increases. It enables the proposed 3S boost converter to have a high drive current (=1.2 A). In addition, the right half-plane (RHP) zero of the proposed topology is related to the switching frequency. By dynamically adjusting the position of RHP zero during transients, the recovery time and output voltage drop can be reduced at the same time. When the load increases from 120 mA to 1.2 A, the recovery time can be accelerated to 42 μ s, and the maximum efficiency can reach 97.4%.

Graphene-functionalized fibers have attracted substantial attention due to their potential applications in flexible wearable electronics. However, these conventional conductive materials face difficulties in mass production, which limits their large-scale fabrication. In this paper, we report a graphene-coated Calotropis gigantea yarn by pad dyeing with graphene oxide and a reduction process, which endows it with high conductivity, outstanding conducting stability, and scale production capacity. By optimizing the dyeing parameters, the modified yarns display a high electrical conductivity of 6.9 S/m. Range analysis results indicate that the electrical conductivity of the graphene-coated yarns exhibits a strong dependence on the concentration of graphene oxide and pad dyeing cycles. The hydrogen bonding between the fiber and graphene during the dyeing process renders the functionalized yarns stable conductivity to washing and bending. Based on the simple fabrication process and fascinating performance, the graphene-coated yarn show great potential in facile scale production of conductive yarns.

Gate valve is mainly used to turn on or turn off the pipeline in pneumatic conveying. When the gate valve is fully open, the particles are easy to collide with the cavity rear wall and enter into the cavity, resulting in particles’ accumulation in the cavity. The particles in cavity will accumulate between the cavity bottom and the flashboard bottom wall and prevent the gate from turning off normally. Meanwhile, the particles’ collision with cavity rear wall will cause serious erosion. Both the particles’ accumulation and erosion will cause the poor sealing of the gate valve, further resulting in the leakage of the pipeline system. To reduce the particles’ accumulation in cavity and erosion on cavity when the gate valve is fully open, we simplify the gate valve into a cavity structure and study it. We find that adding a slope upstream the cavity can effectively reduce the particles’ accumulation in the cavity and the erosion on the cavity rear wall. In this work, Eulerian–Lagrangian method in commercial code (FLUENT) was used to study the gas–solid two-phase flow and erosion characteristics of a cavity with a slope. The particle distribution shows that the particles with Stokes number St = 1.3 and St = 13 cannot enter the cavity due to the slope, but the particles with St = 0.13 enter the cavity following the gas. For St = 13, the particles collide with the wall many times in the ideal cavity. Erosion results show that the slope can transfer the erosion on cavity rear wall to the slope and reduce the maximum erosion rate of the wall near the cavity to some degrees.

Electrochemical nitrogen reduction reaction (NRR) in ambient condition is an efficient and sustainable method to synthesize NH3. In this work, first-principles study was used to discuss the NRR process on B atom doped SbN monolayer. The adsorption of N2 on B-Sb17N18 and B-S18N17 was calculated including the adsorption energy, adsorption distance, and the charge density difference (CDD). Five different reaction pathways of NRR were taken into consideration and the stability of B-SbN was investigated. The results show that, because the energy of unoccupied orbital in sp3 hybridization of B atom is much lower than that in 2pz orbitals, the adsorption of N2 on B-Sb18N17 shows much larger adsorption energy (−1.01 eV with end-on pattern) compared to that of the adsorption on B-Sb17N18. For five different pathways, the 1, 2, and 4 pathways have a smaller limiting potential of about 0.52 V and the limiting step is: *N2 + H+ + e− → *NNH. The 3 and 5 pathways have a larger limiting potential of 0.57 V with hydrogenation step: *NHNH2 + H+ + e− → *NH2NH2. The B-Sb18N17 is structurally and thermally stable even at 500 K. Our theoretical prediction indicates that B atom substitutionally doped SbN monolayer can be a kind of high-performance metal-free NRR catalyst for NH3 synthetization, and the work provides attempts for designing and exploring 2D metal-free NRR catalysts.

In recent years, the manufacturing process of lead zinc niobate-lead titanate [Pb(Zn1/3Nb2/3)O3-PbTiO3, also called PZN-PT] has been enhanced with improvements in size, consistency and a suitable compromise between piezoelectric properties and phase transition temperature, which means that it is possible to obtain PZN-PT single crystals in sufficient size for performance characterization studies and batch manufacturing to produce high-performance medical ultrasonic transducers. This paper mainly focuses on the development of the 64-element phased array ultrasonic transducer based on novel large-size PZN-PT piezoelectric single crystals. The composition of the single crystal was chosen as PZN-5.5 %PT. The designed center frequency of the phased array is 3.0 MHz, which is suitable for cardiac ultrasound imaging. The array elements were spaced at a 0.254 mm pitch, and interconnected through a custom-designed flexible circuit. Double matching layers with a light backing structure were applied in the transducer fabrication process to improve the performance of the array. The test results of the developed phased array showed a center frequency of 3.0 MHz, and an average -6 dB fractional bandwidth of 72%. In the vicinity of the center frequency, the two-way insertion loss (IL) was about -46 dB, while a crosstalk between the adjacent elements was less than -31 dB. The wire phantom can be distinctly imaged with the phased array and the axial and lateral resolutions were measured to be 660 and 1299 μm, respectively. The image of a standard phantom was acquired to present the imaging performance of the transducer. The final results indicate that the transducer arrays based on novel large-size PZN-PT single crystals are quite promising for use in medical ultrasound imaging applications.

Using a combination of polymer acceptors and small molecule donors (SMD/PA-type) is expected to exhibit easier morphology control because of the different diffusion speeds and solubilities due to their relatively large molecular weight difference, but lack of investigation. In this manuscript, we developed two novel small donor molecules Se-1 and Se-2, with alkyl chains in the π-bridge near the donor core or far away from the donor core. We investigated their effects on the molecular properties, morphologies and device performances of the new type of OSCs. The alkyl chains away from the donor core (Se-2) exhibit ordered molecular packing ability, longer exciton lifetime, and an induced face-on packing mode in the blend. Consequently, the Se-2/polymer acceptor blend, with a concurrently high charge generation and low open-circuit voltage loss, reached a best PCE of 10.3%, which is higher than that of the Se-1/polymer acceptor (9.4%). The result shows the highest PCE in the less investigated SMD/PA-type OSCs. Through comparison of other types of OSCs based on the two small donor materials, we find that the small molecules and PJ1 exhibited high miscibility, and we emphasize the importance of enhancing the Flory–Huggins interaction parameter and molecular crystallinity in further photovoltaic material design in SMD/PA-type OSCs.

The tensile and bending process of asymmetric L-shaped aluminum alloy profile is studied by the Abaqus software using the finite element numerical simulation method. The geometric parameters of the ultrasonic-assisted vibration multi-point die (UMPD), and the law of influence on the stress-strain and spring-back of the L-section profile after bending are studied. The results show that the UMPD can reduce the forming stress of the profile during plastic deformation, and the stress-strain distribution of the aluminum profile is more uniform. The changes in the ultrasonic vibration frequency and amplitude of the mold are beneficial to reduce the spring-back of aluminum profiles. The ultrasonic process parameters with a vibration frequency of 20 kHz and an amplitude of 0.02 mm have the best effect on suppressing spring-back, which is reduced by 20.6% compared to the case of no ultrasonic application. Finally, it is verified by experiments that the experimental results are basically consistent with the simulation results, and the changing trend of spring-back deformation is consistent.

Amorphous aluminum oxide (alumina) thin films are of interest as inert chemical barriers for various applications. However, the existing literature on the aqueous stability of atomic layer deposited (ALD) amorphous alumina thin films remains incomplete and, in some cases, inconsistent. Because these films have a metastable amorphous structure─which is likely partially hydrated in the as-deposited state─hydration and degradation behavior likely deviate from what is expected for the equilibrium, crystalline Al2O3 phase. Deposition conditions and the aqueous solution composition (ion content) appear to influence the reactivity and stability of amorphous ALD alumina films, but a full understanding of why these alumina films hydrate, solvate, and/or dissolve in near-neutral pH = 7 conditions, for which crystalline Al2O3 is expected to be stable, remains unsolved. In this work, we conduct an extensive X-ray photoelectron spectroscopy investigation of the surface chemistry as a function of water immersion time to reveal the formation of oxyhydroxide (AlOOH), hydroxide (Al(OH)3), and possible carbonate species. We further show that brief postdeposition exposures of these ALD alumina films to an air plasma anneal can significantly enhance the film's stability in near-neutral pH aqueous conditions. The simplicity and effectiveness of this plasma treatment may provide a new alternative to thermal annealing and capping treatments typically used to promote aqueous stability of low-temperature ALD metal oxide barrier layers.

In the flexible stretch bending of multi-point roller dies process, the deformation of workpiece is mainly driven by clamps. Therefore, the movement track of clamp has a great influence on the forming effect of workpiece. Y-profile, T-profile, and L-profile are taken as the research objects. Simulation and experiments are carried out with two different movement tracks. The influence of the movement tracks on shape error, springback error, and thickness variation of different profiles is discussed. The experimental results of the three profiles processed by the double-sided forming method are consistent with the simulation results, which proves the accuracy of the numerical simulation. The results show that the movement track has a great influence on shape error. Compared with double-sided forming, one-sided forming can effectively reduce springback error. The two different movement tracks have no obvious influence on thickness change.

It is critical to repair severed facial nerves, as lack of treatment may cause long-term motor and sensory impairments. Ciliary neurotrophic factor (CNTF) plays an important role in terms of enhancing nerve axon regrowth and maturation during peripheral nerve regeneration after injury. However, simple application of CNTF to the transected nerve site does not afford functional recovery, because it is rapidly flushed away by bodily fluids. The aim of the present study was the construction of a new, bioactive composite nerve graft facilitating persistent CNTF delivery to aid the reconstruction of facial nerve defects. The in vitro study showed that the bioactive nerve graft generated sustainable CNTF release for more than 25 days. The bioactive nerve graft was then transplanted into the injury sites of rat facial nerves. At 6 and 12 weeks post-transplantation, functional and histological analyses showed that the bioactive nerve graft featuring immobilized CNTF significantly enhanced nerve regeneration in terms of both axonal outgrowth and Schwann cell proliferation in the rat facial nerve gap model, compared to a collagen tube with adsorbed CNTF that initially released high levels of CNTF. The bioactive nerve graft may serve as novel, controlled bioactive release therapy for facial nerve regeneration.

With the advantage of excellent light absorption ability and earth-abundant elements, Cu2ZnSnS4 (CZTS) is widely applied in the photoelectrochemical (PEC) reduction of CO2. However, the microscopic...

The dissolution behaviors of various minerals in the tellurium–bismuth ore during oxidic–acidic leaching were investigated systematically in this work. The Te–Bi phase in the ore distributes in network shape, triangular shape, tree shape, strip shape, bulk shape, sparse granule, flake shape, crescent, etc., which are closely intercalated with FeS, FeS2, and CaCO3·(Mg,Fe,Mn)CO3. Under suitable conditions, 95.61% Te and 95.77% Bi can be recovered. Within 20 min of the initial leaching, most of dolomite and Te–Bi phase dissolve rapidly. With the extension of leaching time, a large amount of rod-shape CaSO4 particles form, attach on the surface of the tellurium–bismuth ore particles, and then grow and coarsen. The (Mg,Fe,Al)(Si,Al)Ox(OH)y phase dissolves mainly within 60 min. Fe–S phase can be corroded but cannot dissolve completely. SiO2 cannot dissolve at all. Besides, H2SO4 and Fe3+ play a significant role on the dissolution of various minerals in the ore. Without Fe3+ or H2SO4 in immersion liquid, Te and Bi are difficult to be leached into the lixivium from the tellurium–bismuth ore. As H2SO4 concentration and Fe3+ concentration increase, Te–Bi phase and Fe–Mg–Al–Si–O phase gradually dissolve, the Fe–S phase can be corroded obviously but cannot dissolve, and the Si–O phase has no change. The dissolution of dolomite is mainly controlled by H2SO4. The dissolution behaviors of various minerals in the tellurium–bismuth ore during oxidic–acidic leaching were investigated systematically. Most of dolomite and Te–Bi phase dissolve rapidly. A large amount of rod-shape CaSO4 particles form, attach on the surface of the tellurium–bismuth ore particles, and then grow and coarsen. H2SO4 and Fe3+ play a significant role on the dissolution of various minerals in the ore.

Surface mechanical nano-alloying treatment (SMNAT) was employed to fabricate a nanostructured Ti coating on LZ91 Mg–Li alloy. Microstructure, surface hardness and in-vitro biocompatibility of the Ti-coated sample were investigated in comparison with those of an untreated sample. Experimental results showed that a nanostructured Ti coating with a thickness of 35 to 60 μm was formed after SMNAT for 2 h. The average grain size in the top surface of the Ti coating was about 30 nm. The surface of the Ti coating is rougher than that of the untreated LZ91 sample, in which the values of Ra, Rq and Rz were 7.83, 9.57 and 14.85 μm, respectively. The hardness of the Ti coating top surface was about 483 HV. Cell proliferation and differentiation on Ti coated samples were enhanced relative to those on the untreated samples.

A new type of Ni–Co based superalloy was prepared by vacuum induction melting (VIM), and the effects of superheat on element distribution, dendrite segregation, and solidification microstructure refinement of the new Ni–Co based superalloy are revealed. The effect of solidification structure treatment under different conditions was quantitatively studied by differential scanning calorimetry (DSC), scanning electron microscope (SEM), and electron probe micro analyzer (EPMA). The results indicated that the nucleation undercooling increased and the crystallization temperature interval decreased with the rise of the melt temperature; As the superheat temperature rised, the size of the phase was refined; the secondary dendrite arm spacing of the alloy decreased continuously; and the dendritic segregation of the alloy decreased. It was found that the critical temperature of melting energy for the new Ni–Co based superalloy clusters is about 1550 °C. The maximum positive segregation element of the new Ni–Co-based superalloy is Ti, and the maximum negative segregation element is W; When the temperature increased from 1450 °C to 1600 °C, the segregation coefficient of Ti increased from 0.54 to 0.63, and the segregation coefficient of W decreased from 1.9 to 1.5. When the superheat was increased, the atomic cluster size decreases, and the effect of refining the solidification structure of the new Ni–Co-based superalloy is more significant.

The punching and post-punching shear behaviours of reinforced concrete (RC) flat plate structures are often studied by using a representative slab–column connection isolated from the parent structure. In this study, a set of numerical modelling techniques is established to create a competent three-dimensional non-linear model to simulate punching and post-punching shear behaviours of RC slab–column connections without shear reinforcement, through the use of which the punching shear failure featuring a critical punching shear surface and an abrupt drop of the applied force in the load–displacement response is able to be accurately reproduced. The post-punching shear behaviour, taking the form of an increased load-carrying capacity which is ceased by rebar fracture in the suspension stage, is also well captured. Using the proposed numerical model, typical punching and post-punching shear failure mechanisms are studied in some detail.

The superplastic forming process has been used extensively in aerospace applications for its advantages in manufacture of complicated components. But it has been limited to the long production cycle and the non-uniform thickness distribution of the final formed part. The two-stage SPF process in opposite directions for 5083 aluminum alloy door frames was investigated. A finite element model in PAMSTAMP was used to simulate the forming process. Analyzed the effect of pre-forming die parameters on the minimum thickness of the final formed part by the Response Surface Methodology and optimized the pre-forming die parameters. Moreover, the influence of different rated pressure on the forming quality and forming time of the door frames under the same strain rate were investigated to determine the ideal pressure profile. The result was that the minimum thickness meets the requirements (thinning not exceeding 40%) while reducing the production cycle. Finally, the two-stage superplastic forming experiment in opposite directions was conducted to verify the accuracy of the numerical simulation and produce the door frames with high quality.

Nature-inspired gradients can be implemented in metallic materials to achieve a synergy of strength and ductility. However, due to the small (often microscale) size of the gradient structured samples, their fracture properties have remained relatively unexplored. By fabricating centimeter-sized gradient-structured pure nickel samples using direct-current electroplating technique, we demonstrate that a dual-gradient architecture in pure nickel, comprising grain-size transitions from coarse grains to nano grains and then back to coarse grains (CG→NG→CG), achieves an optimized combination of strength-ductility synergy and exceptional fracture resistance – a crack-initiation toughness exceeding 300 MPa m½ – while minimizing the problem of final unstable catastrophic failure. Significantly, this dual-gradient CG→NG→CG structure can effectively arrest any brittle fracture in the nano grains by inducing a stable rising R-curve with an enhanced crack-growth toughness exceeding 350 MPa m½. We believe that this dual-gradient CG→NG→CG structure provides a promising prototype for designing multi-layer graded structures with exceptional combinations of mechanical properties which can be readily tuned to meet the advanced requirements of safety-critical applications.

Pinning of a three-phase contact line at the nanoscale cannot be explained by conventional macroscale theories and thus requires an experimental insight to understand this phenomenon. We performed in-situ transmission electron microscopy observation of the three-phase contact lines of bubbles inside graphene liquid cells to experimentally investigate the causes of nanoscale pinning. In our observations, the three-phase contact line was not affected by the 0.6 nm-thick inhomogeneity of the graphene surface, but thicker metal nanoparticles with diameters of 2-10 nm and nanoflakes caused pinning of the gas-liquid interface. Notably, we found that flake-like objects can cause pinning that prevents the bubble overcome the flake object in a noncontact state, with a 2 nm-thick liquid film between them and the bubble. This phenomenon can be explained by the repulsive force obtained using the Derjaguin, Landau, Verwey, and Overbeek theory. We also observed that the flake temporally prevented the gas-liquid interface moving away from the flake. We discussed the physical mechanism of the attractive force-like phenomenon by considering the nanoconfinement effect of the liquid sandwiched by two graphene sheets and the hydration layer formed near the solid surface.

The adsorption behaviors of CO2 at the Cu n /TiC(001) interfaces (n = 1-8) have been investigated using the density functional theory method. Our results reveal that the introduction of copper clusters on a TiC surface can significantly improve the thermodynamic stability of CO2 chemisorption. However, the most stable adsorption site is sensitive to the size and morphology of Cu n particles. The interfacial configuration is the most stable structure for copper clusters with small (n ≤ 2) and large (n ≥ 8) sizes, in which both Cu particles and TiC support are involved in CO2 activation. In such a case, the synergistic behavior is associated with the ligand effect introduced by directly forming adsorption bonds with CO2. For those Cu n clusters with a medium size (n = 3-7), the configuration where CO2 adsorbs solely on the exposed hollow site constructed by Cu atoms at the interface shows the best stability, and the charger transfer becomes the primary origin of the synergistic effect in promoting CO2 activation. Since the most obvious deformation of CO2 is observed for the TiC(001)-surface-supported Cu4 and Cu7 particles, copper clusters with specific sizes of n = 4 and 7 exhibit the best ability for CO2 activation. Furthermore, the kinetic barriers for CO2 dissociation on Cu4- and Cu7-supported TiC surfaces are determined. The findings obtained in this work provide useful insights into optimizing the Cu/TiC interface with high catalytic activation of CO2 by precisely controlling the size and dispersion of copper particles.

Two-dimensional (2D) IV–VI nanomaterials have been important candidates for energy conversion and storage. However, there is still lack of a simple method of realizing control synthesis of IV–VI na...

Biliary atresia is the most common cause of childhood liver disease and is the main cause of liver replacement. The use of an effective early screening technique can efficiently improve the therapeutic effect on children with biliary atresia, especially those in the remote rural areas. This study introduces a novel method for detecting direct bilirubin by Raman spectroscopy using composite surface-enhanced Raman spectroscopy (SERS) chips. These chips were created by spreading silver nanowires on the nanostructure surface of an anodic aluminum oxide substrate. Experimental results demonstrated that the detection limit of direct bilirubin concentration vastly improved far below the disease criteria of bilirubin in adults and infants. Meanwhile, using only $10~\mu \text{L}$ of direct bilirubin, a wide detection range from 10−7 to 10−4 M was obtained, covering the clinic reference range with R2 of 0.98336 at the peak value of 1.616 cm−1. Furthermore, the results revealed that the proposed composite SERS substrates possessed good statistical relative standard deviation and reproducibility (N = 3) of 4.6% and 2.2%, respectively. Thus, the composite SERS chip combined with the Raman spectroscopy approach can be integrated with portable Raman spectrometer for the effective clinical detection of direct bilirubin.

The mesoscopic solution-state aggregation plays a dominant role in the multilevel self-assembly of conjugated polymers. However, its effect on solid-state microstructures and the electrical perform...

Over recent years, eutectic high-entropy alloys (EHEAs) have intrigued substantial research enthusiasms due to their good castability as well as balanced strength–ductility synergy. In this study, a bulk cast Al19.25Co18.86Fe18.36Ni43.53 EHEA is developed with fine in-situ lamellar eutectics. The eutectics comprise alternating ordered face-centered-cubic (L12) and ordered body-centered-cubic (B2) phases with semi-coherent interfaces. The resulting microstructure resembles that of most reported as-cast EHEAs, but the B2 lamellae are devoid of nano-precipitates because of the Cr-element removal in current tailored eutectic composition. Surprisingly, the B2 lamellae still feature much higher deformation resistance than the L12 lamellae, so that less lattice defects are detected in the B2 lamellae until the fracture. More interestingly, in the L12 lamellae we identify a dynamic microstructure refinement that correlates to extraordinary strain hardening in tension. The precipitate-free EHEA consequently shows excellent tensile ductility of ∼10 % and high ultimate strength up to ∼956 MPa.

In this paper, SnO2 nanoparticles were designed and synthesized by the hydrothermal method. It was confined to a jute fiber cellulose carbon (JFCC) framework, which was equivalent to a biomass carbon buffer layer wrapped around SnO2 nanoparticles. The combination of SnO2 nanoparticles and the amorphous carbon buffer layer alleviated the volume expansion effect of SnO2 to a certain extent, shortened the lithium-ion diffusion path, and improved the conductivity. At 0.2C, the discharge specific capacity of the composite (SnO2@JFCC) was finally stabilized at 1298.5 mAh g−1 after 100 cycles. The discharge specific capacity was stabilized at 1090.3 mAh g−1 for 1000 cycles at 2C, which further showed the good synergy between SnO2 nanoparticles and JFCC and exhibited excellent lithium storage performance.

Even though high-strength steel has been widely used across the world, the global buckling behaviour of high-strength steel beams has yet to be systematically investigated through experimental tests and numerical simulations. This paper describes an experimental and numerical study of the lateral-torsional buckling resistance of welded Q690 steel beams. Eight beams with doubly-symmetric cross-sections and different height-to-width ratios were tested under a concentrated point load. To allow free lateral deflections, a special loading system was designed and erected at the mid-span of steel beams. The applied load remained in the vertical direction during the whole loading process, despite significant rotations and lateral deflections of the beam. The critical bending moment of steel beams was quantified in the experimental tests. Besides, numerical models were established by using ABAQUS and initial imperfections were properly defined in the model. Direct comparisons were made among numerical results of steel beams of different steel grades and design curves in different standards. Based on experimental and numerical results, recommendations were provided for the lateral-torsional buckling design of Q690 steel beams. It was suggested that GB50017-2003 and GB50017-201X can predict the buckling resistance of Q690 steel beams with slightly conservative results, Eurocode 3 yields rather conservative estimations, but ANSI/AISC360-10 significantly overestimates the buckling resistance.

A series of pyridinium-based chiral ionic liquid crystals were designed and synthesized. All of them exhibit enantiotropic smectic phases. The methylation on the pyridine ring not only decreases th...

Triplet-triplet annihilation (TTA) upconversion has shown promising potentials in the augmentation of solar energy conversion. However, challenging issues exist in improving TTA upconversion efficiencies in solid-states, one of which is the back energy transfer from upconverted singlet annihilators to sensitizers, resulting in decreasing upconversion emission. Here we present a light-harvesting molecular wire consisting of dendrons with 9,10-diphenylanthracene derivatives (DPAEH) at the periphery and p-phenylene ethynylene oligomers (PPE) as the wire core. The peripheral DPAEH antenna funnels singlet excitonic energy to the wire on a 12 ps time scale. Incorporating the molecular wire into the TTA upconversion solid consisting of the DPAEH annihilator and the porphyrin sensitizer evidently improves the upconversion quantum yield from 1.5% to 2.7% upon 532 nm excitation by suppressing the back energy transfer from the singlet annihilator to the sensitizer. This finding offers a potential route to use a singlet energy light-harvesting architecture for enhancing TTA upconversion.

Two series of acrylate liquid crystals with enantiotropic SmA and SmC phases were synthesised. With increasing the alkoxy chain length, SmC phase was favourable to be formed. The mesophases were confirmed by taking small angle X-ray scattering patterns. Moreover, a diacrylate liquid crystal with an enantiotropic SmA phase was synthesised. Smectic liquid crystal mixtures were prepared using the diacrylate liquid crystal (or a mixture of an acrylate liquid crystal and the diacrylate one) and a dichroic dye. After photopolymerisation at the SmA phase, polymeric polarisers were obtained. The degree of polarisation was increased with increasing the dye concentration and film thickness.

Mitochondria are the power plants of the cell and play key roles in activating the apoptotic pathway in cancer cells, which are readily susceptible to cytotoxic reactive oxygen species and temperature elevations. Herein, we develop a “nanomissile” that targets mitochondria to enhance tumor treatment effects by facilitating mitochondrial dysfunction and releasing cytochrome C to activate the apoptotic pathway of cancer cells under 650-nm laser irradiation. Porphyrin-grafted polydopamine nanomaterial (PTPF-MitP) is designed as a nanomissile, with integrated O2-evolving photodynamic therapy and moderate photothermal therapy, which can selectively deliver to the mitochondria through a targeting unit, MitP. The cytotoxicity of PTPF-MitP to human lung tumor cells is twice as high as that of PTPF that does not have mitochondrial targeting units. In addition, it represents a realtime visualization and highly efficient treatment for tumor sites in vivo. This development represents a viable strategy for cancer therapy.

Birnessite-MnO2 nanoflakes were synthesized via an aqueous oxidation method at 90 °C using Mn(CH3COO)2, NaOH, and KMnO4. The samples’ morphology, crystalline structure, and optical property were determined by field emission scanning electron microscopy, X-ray powder diffraction and UV-Vis spectrophotometry. The birnessite-MnO2 nanoflakes were converted to KxMn8O16 and Mn suboxides following a decrease in the concentration of KMnO4 in the reaction. The amount of NaOH in the reaction determined the type of precursor. Without NaOH, the precursor was converted from Mn(OH)2 to Mn2+ (from Mn(CH3COO)2), thereby enabling the synthesis of birnessite-MnO2 nanoflowers. The formation mechanism of birnessite-MnO2 nanoflowers and nanoflakes was clarified via the corresponding simulated crystal structures. Evaluation of the synthesized samples confirmed that the birnessite-MnO2 nanoflakes and nanoflowers exhibited excellent degradation properties.

Crystal structure of conjugated molecules and polymers is fundamentally critical to understand their multilevel microstructures, carrier transport, and diverse functions. However, to determine the crystal structure of conjugated polymers is a significant challenge, mainly due to the poor crystallinity, weak diffraction, and instability under high‐energy radiation. Here, we build the possible crystal structures of eight typical conjugated polymers, covering several widely used molecular segments in organic optoelectronics. We model the packing structures of these seed polymers based on synchrotron X‐ray diffractions and molecular simulations. These crystal structures provide a new platform to predict the packing structures of more related polymer systems, extending the molecular scope. Based on this polymer crystal structure database, the multiscale microstructures and charge transport properties of conjugated polymers can be predicted before experiments. This study sets up a polymer crystal structure database to eliminate the current trial‐and‐error approaches and accelerating the design of high‐performance conjugated polymers.

Collisions between particles and the wall covered by a liquid layer play an important role in many different industrial processes (e.g., chemical, pharmaceutical, and transportation). Understanding the rebound motion law of the collision between particles and the wall covered by a liquid layer is vital to ensure the high efficiency of processes such as wet granulation and fluid catalytic cracking. In the present study, we investigated the influence of different collision angles on the liquid bridge geometry, particle motions, particle energy, and other collision details based on the oblique collisions between particles and the target plate covered by a liquid layer. Results showed that the collision angle of particles has a great effect on the liquid bridge geometry. Moreover, the liquid bridge caused by different collision angles initially increases the particle deflection angle difference and then decreases, and this influence gradually increases with the increase of the collision angle. In addition, the collision angle greatly affects the particle’s energy.

The tribological behavior of the friction pairs in a high-pressure vane pump under variable working conditions was experimentally studied; in particular, the effects of the varying sliding velocity (1.45–3.61 m/s) and contact pressure (0.11–0.44 MPa) on the friction coefficient and wear rate of the friction pairs in pumps with and without vanes in the vane slot of rotor were investigated. In both cases, the friction coefficient increased with increasing sliding velocity and decreased when the increase of contact pressure in two cases when the contact pressure is 0.22 MPa. Further, the wear rate decreased with increasing contact pressure. With increasing velocity, the friction coefficient was more influenced by the vane compared with wear rate. The main tribological mechanism of wear surface of the valve plate is mechanical ploughing. At a sliding velocity of 2.89 m/s, both with and without vanes, increasing the contact pressure resulted in a reduced friction coefficient and enhanced wear rate. When the contact pressure increased, the vane did not significantly influence the friction coefficient and wear rate. During this time, the wear surface morphology of the valve plate exhibited mainly mechanical plowing and adhesion wear marks.

High sensitivity of sensors is extremely significant for precisely monitoring imperceptible changes of motion in real-time, which cannot be achieved by traditional piezoelectric devices. Herein, a hierarchical polyvinylidene fluoride hexafluoropropylene (PVDF-HFP)/ZnO composite nanaofiber piezoelectric sensor with highly sensitivity has been prepared through epitaxial growing ZnO nanosheets on the surface of electrospun PVDF-HFP nanofibers. Systematic investigations have shown that their optimum pressure sensing performance with a sensitivity of 1.9 V kPa−1 and a short response time of 20 ms are achieved for forces from 0.02 to 0.5 N with excellent durability and stability up to 5000 cycles. Moreover, this sensor can precisely detect the imperceptible changes in player’s motions to avoid injury from overtraining. Additionally, a Bluetooth-low-energy that tracks player’s workout and transmits the output signals wirelessly to a smartphone app is utilized. The study provides a feasible approach for high-precision detecting and safety monitoring in the fields of medical, rehabilitation medicine, and workout security.

Zeolites are a family of microporous crystalline materials, which, since the 1940s, have had an indispensable role in the chemical industry as catalysts, adsorbents and ion exchangers. Advances in synthetic methodologies and characterization techniques have enabled the fabrication of new zeolitic materials, with emerging applications in diverse areas. By tuning their porous architectures, framework compositions and crystal morphologies, coupled with the incorporation of exotic active species, zeolites and zeolite-based materials have exhibited unprecedentedly high performance in many challenging processes. In this Review, we focus on the high-efficiency catalytic production of industrially important hydrocarbons and oxygenates using non-petrochemical feedstocks, energy-efficient separations of hydrocarbon mixtures that are difficult using conventional methods and materials, and host–guest assemblies that exhibit physical properties unprecedented to either the zeolite hosts or free guest species. Finally, we provide our perspectives on future directions for the development of zeolitic materials to meet the ever-growing demands from diverse fields. New zeolitic materials have shown high performance in emerging applications across diverse areas. This Review focuses on the advances in zeolite applications, including the catalytic production of hydrocarbons and oxygenates from non-petrochemical feedstocks, the efficient separation of hydrocarbon mixtures that are otherwise challenging, and host–guest assemblies with unprecedented physical properties.

The slotted cartridge is able to generate strong directional penetration. To study the effect of different structures of slotted cartridges on the propagation characteristics of shock waves and explosive products, the high-speed schlieren photography system and pressure testing system were used to conduct experimental investigations based on five different structures of slotted cartridges. Experimental results show that shock waves and explosive products preferentially propagate outward from the slit and the propagation process is highly symmetrical. The peak overpressure generated by the three-seam slotted cartridge is 1.4 MPa, which is much greater than that of other design schemes. Besides, the greatest propagation velocities of shock waves and explosive products were achieved for the three-seam slotted cartridge. The disturbance of adjacent shock waves generates jet-like explosive products in front of the shock waves. Numerical simulations reveal that there are two rising phases of overpressure at the slotted position, which is mainly caused by air disturbance in the slit and shock wave reflection in the slotted tube. The three-seam slotted cartridge achieves the maximum overpressure of 225 MPa at the slotted position. When the shock waves and explosive products propagate outward the slotted cartridge with large internal incision, the overpressure and velocities of shock waves and explosive products gradually increase with decrease in the cross-sectional area of the slotted tube.

In human-made malleable materials, microdamage such as cracking usually limits material lifetime. Some biological composites, such as bone, have hierarchical microstructures that tolerate cracks but cannot withstand high elongation. We demonstrate a directionally solidified eutectic high-entropy alloy (EHEA) that successfully reconciles crack tolerance and high elongation. The solidified alloy has a hierarchically organized herringbone structure that enables bionic-inspired hierarchical crack buffering. This effect guides stable, persistent crystallographic nucleation and growth of multiple microcracks in abundant poor-deformability microstructures. Hierarchical buffering by adjacent dynamic strain-hardened features helps the cracks to avoid catastrophic growth and percolation. Our self-buffering herringbone material yields an ultrahigh uniform tensile elongation (~50%), three times that of conventional nonbuffering EHEAs, without sacrificing strength.

Photocatalytic hydrogen production by overall water solar-splitting is a prospective strategy to solve energy crisis. However, the rapid recombination of photogenerated electron-hole pairs deeply restricts photocatalytic activity of catalysts. Here, the in-situ transient photovoltage (TPV) technique was developed to investigate the interfacial photogenerated carrier extraction, photogenerated carrier recombination and the interfacial electron delivery kinetics of the photocatalyst. The carbon dots/NiCo2O4 (CDs/NiCo2O4) composite shows weakened recombination rate of photogenerated carriers due to charge storage of CDs, which enhances the photocatalytic water decomposition activity without any scavenger. CDs can accelerate the interface electron extraction about 0.09 ms, while the maximum electron storage time by CDs is up to 0.7 ms. The optimal CDs/NiCo2O4 composite (5 wt.% CDs) displays the hydrogen production of 62 µmol·h−1g−1 and oxygen production of 29 µmol·h−1g−1 at normal atmosphere, which is about 4 times greater than that of pristine NiCo2O4. This work provides sufficient evidence on the charge storage of CDs and the interfacial charge kinetics of photocatalysts on the basis of in-situ TPV tests.

In the process of flexible 3D stretch bending, the shape deviation difference between the contact zone and non-contact zone is studied. It is obvious that in the contact zone, the die regulates the deformation of the profile to make it conform to the target shape with small shape deviation; in the non-contact zone, the profile has no die restriction and deviates from the target shape with large shape deviation. When the dies are placed equidistantly along the x-axis, the shape deviation of the non-contact zone near the clamp side is greater than that near the middle of the profile. Arrange the distance between adjacent dies in equal ratio along the x-axis, so that the spacing near the clamp side is a little smaller, and the spacing near the middle of the profile is a bit larger. The difference between the shape deviation of the non-contact zone profile near the clamp side and the middle of the profile decreases, and the maximum shape deviation is reduced, which greatly improves the processing accuracy and quality. However, with the increase of the distance difference between adjacent dies, the shape deviation difference of the non-contact zone near the middle of the profile also increases greatly. Although the clamp side decreases, the maximum shape deviation has become the shape deviation of the profile in the non-contact zone near the middle of the profile.

In order to effectively improve the environmental problems caused by steel slag stacking, the air-quenching process of molten steel slag was carried out, and the properties of the air-quenched steel slag (AQSS) has been investigated by various characterization methods. The results show that the main phases of AQSS were Ca2SiO4, RO phase (solid solution formed by MgO, FeO, and MnO) and Ca2Fe2O5. The AQSS met the technical requirements of a sandblasting abrasive. In addition, the Rockwell hardness of the AQSS with particle size of 1.0–3.0 mm exceeded 50.00 HRC. The particle size of 1–2.5 mm was particularly adapted to use as a sandblasting abrasive. It is clear that AQSS can be used as a sandblasting abrasive by analyzing and comparing the particle size and hardness of the AQSS and commonly used sandblasting abrasives.

The role of solution aggregates on the charge transport process of conjugated polymers in electronic devices has gained increasing attention; however, the correlation of the charge carrier mobilities between the solution aggregates and the solid-state films remains elusive. Herein, three polymers, FBDOPV-2T, FBDOPV-2F2T, and FBDOPV-4F2T, are designed and synthesized with distinct aggregation behavior in solution. By combining contact-free ultrafast terahertz (THz) spectroscopy and field-effect transistor measurements, we track the charge carrier mobility of the aggregates of these polymers from the solution to the thin-film state. Remarkably, the mobility of these three polymers is found to follow nearly the same trend (FBDOPV-2T>FBDOPV-2F2T≫FBDOPV-4F2T) in both solutions and thin-film states. The quantitative mobility correlation indicates that the charge transport properties of solution aggregates play a critical role in determining the thin-film charge transport properties and final device performance. Our results highlight the importance of investigating and controlling solution aggregation structures towards efficient organic electronic devices.

To reveal the suppression characteristics of methane/coal dust deflagration flame propagation by the flue gas loading in local zones. The suppression experiments of flue gas layer (CO2 and fly ash) with different thicknesses and fly ash concentrations were conducted in semi-open vertical combustion pipe. The flue gas layer was produced by self-designed flue gas layer generator. Flame propagation characteristics which including the flame image, velocity, the ion current and temperature were recorded by the high-speed photography, the ion current probe and the thermocouple. The residues after coal dust deflagration were characterized by FTIR (Fourier transform infrared spectroscopy). The results show that the flue gas layer has a significant suppression on deflagration flame propagation. With the increasing of flue gas layer thickness and fly ash concentration, the flame velocity, height, temperature and the ion current gradually decreases, and the suppression effect was enhanced. The asphyxiation of CO2, heat absorption and insulation of fly ash were mainly methods for the suppression of coal dust deflagration flame.

We present a design overview of the MIT 1.3-GHz LTS/HTS NMR magnet (1.3G) with a newly designed 835-MHz REBCO insert (H835) as a replacement for the 800-MHz REBCO insert (H800) that was damaged when it quenched during operation in 2018. The new H835 is designed to contribute 19.6 T in a background field of 10.93 T by an LTS NMR magnet that normally rated at 11.74 T (500 MHz): combined, 1.3G generates a total field of 30.53 T corresponding to a proton resonance frequency of 1.3 GHz. H835 is designed to operate stably while meeting 1.3G design constraints. We have also designed H835 to protect it from permanent damage in an improbable event like a quench. Key design features are: 1) a single-coil formation, composed of 38 stacked metal-co-wound no-insulation and 2 stacked no-insulation double-pancake coils, all with mechanically improved cross-over sections; 2) enhanced thermal stability; and 3) reduced current margin with a detect-and-heat method. This paper includes: 1) electromagnetic and mechanical design of H835; 2) cryogenics overview; 3) quench protection strategy; and 3) discussion on the next steps to successfully complete 1.3G.