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The disinfection of waterborne pathogens from drinking water is extremely important for human health. Although countless efforts have been devoted for drinking water inactivation, challenges still exist in terms of relative high energy consumption and complicated to implement and maintain. Here, silver nanoparticles anchoring wood carbon (Ag NPs/WC) membrane is developed as cost-effective, high flux, scalable filter for highly efficient electric field disinfection of water. Under electric field of 4 V voltage, the designed membrane achieved more than 5 log (99.999%) disinfection performance for different model bacteria, including Escherichia coli (E. coli), Enterococcus faecalis (E. faecalis), Salmonella enterica serovar Typhimirium (S. Typhimurium) and Bacillus subtilis (B. subtilis) with a high flux of 3.8 × 103 L m−2 h−1, extremely low energy consumption of 2 J L−1 m−2 and fantastic durability (7 days). The high disinfection performance of Ag NPs/WC membrane is attributed to the synergistic disinfection of carbon nanofibrils, Ag nanoparticles as well as the low tortuous structure of the channels in wood carbon. The Ag NPs/WC membrane presents a promising strategy for point-of-use drinking water electric field disinfection treatment.

Many hierarchical structures have good mechanical properties, which can better improve the energy absorption characteristics and achieve lightweight. This article proposed a novel circumferential s...

Reinforced soil structures are often subjected to both static and dynamic loads. However, experimental data concerning the interaction of soil–geosynthetic interfaces under normal dynamic loads are scarce. This paper reports on a series of large-scale direct shear tests that are used to investigate the shear behaviour of a gravelly soil–geogrid interface under normal cyclic load (NCL) conditions. The results show that the shear stress magnitude under NCL conditions is generally between the shear stresses under normal static load (NSL) conditions corresponding to the upper and lower bounds of the NCL. The upper and lower envelopes of the shear stress–displacement curve increase with increasing initial stress and amplitude. The enhancement coefficient ([Formula: see text]) is used to describe the degree of influence of the additional cyclic load on the shear stress of the interfaces. The relative time shift between the shear stress ratio ([Formula: see text]) and the normal stress ([Formula: see text]) is nearly a constant of 0.5 cycles, and the influence of the initial stress on the stress ratio is opposite to that of the amplitude. Finally, the volume change response is discussed under different normal load conditions.

Cryo-electron microscopy (cryo-EM) has emerged as a vital tool to reveal the native structure of beam-sensitive biomolecules and materials. Yet high-resolution cryo-EM analysis is still limited by the poorly controlled specimen preparation and urgently demands a robust supporting film material to prepare desirable samples. Here, we developed a bilayer Janus graphene membrane with the top-layer graphene being functionalized to interact with target molecules on the surface, while the bottom layer being kept intact to reinforce its mechanical steadiness. The ultraclean and atomically thin bilayer Janus membrane prepared by our protocol on one hand generates almost no extra noise and on the other hand reduces the specimen motion during cryo-EM imaging, thus allowing the atomic-resolution characterization of surface functional groups. Using such Janus membranes in cryo-EM specimen preparation, we were able to directly image the lithium dendrite and reconstruct macromolecules at near-atomic resolution. Our results demonstrate the bilayer Janus design as a promising supporting material for high-resolution cryo-EM and EM imaging.

The accurate determination of the interface shear strength is essential in the design of geosynthetic-reinforced soil structures. The particle geometries of three types of soil materials and a spherical granular medium are imaged and quantified using binary image-based methods and described in terms of regularity. Cyclic direct shear tests are conducted to investigate the effects of particle regularity on the interface shear strength, stress–displacement relationship, shear stiffness, and damping ratio. The results reveal that the interface shear strength and deformation strongly depend on particle regularity. The vertical displacement ratio is found to increase with particle regularity under the same cycle number. The interface stiffness is observed to increase with the cycle number for particle regularities of 0.453, 0.565, and 0.672 but decreases with the cycle number for a particle regularity of 0.971. For a given regularity, the trend of damping ratio with the increasing cycle number is contrary to the that of shear stiffness. Finally, it is observed that the cyclic friction angle decreases with increasing particle regularity, the relationship of which is determined using linear regression. Thus, the systematic quantification of particle shape characteristics can lead to a better understanding of soil–geogrid interface behaviour.

Thin-walled tubes are widely used as energy absorption devices because of their excellent crashworthiness. In this paper, a novel tubular configuration with a double-layer sinusoidal corrugated sec...

The three-dimensional (3D) display technology has always been a hot spot in the display field. The core of augmented reality (AR), virtual reality (VR), and naked-eye 3D display are to visually regulate the light entering the human eye to form a binocular parallax, that is, a visual deviation in the image of the two eyes, which produces a stereoscopic sense in the human brain. In the AR and VR display field, we always pursue a perfect immersive visual experience, which poses great challenges to the wide field of view (FOV) and high resolution of the system. As a new type of polymer material, liquid crystal polymers are widely used in AR and VR because of their unique optoelectronic properties, such as scattering or transparency with the change of an applied electric field. In this paper, we review some key challenges in the field of AR and VR display, such as the well-known vergence-accommodation conflict (VAC), and propose solutions that have been proven effective. We introduce the important functions and optoelectronic properties of liquid crystal (LC) materials by describing in detail the working principle of polymer dispersed liquid crystal (PDLC), doublet geometric phase (GP) lens, and polymer-stabilized liquid crystal (PSLC). Finally, we summarize and discuss the main uses and challenges of liquid crystal materials in the field of AR and VR displays.

With the development of modern technology and people’s demand for improving living standards, the traditional 2D display cannot meet the needs of people, so the augmented reality (AR) technology which combines virtual objects with real environment arises at the historic moment. AR technology sprouted in the 1960 s, and ushered in rapid development in the 21st century through continuous technical iteration. However, the traditional AR system cannot solve the vergence-accommodation conflict (VAC), to solve which, researchers introduced liquid lens into the optical system of AR. The methods and materials of making liquid lens are different. In this paper, the research progress of liquid lens is summarized from three aspects. Firstly, the research progress of liquid lens is briefly reviewed. Secondly, the classification and typical preparation technology of liquid lens are introduced, and different requirements for performance are described. Finally, the performance and testing method of liquid lens is introduced.

Ni-rich layered LiNi0·6Co0·2Mn0·2O2 materials have recently drawn much attention for their high specific capacity. However, they still suffer from the cycling instability arising from Li+/Ni2+ ions mixing in crystal structure and harmful side reactions with electrolyte, especially charged at high cut-off voltage to achieve higher energy density. In this study, the Li(Ni0·6Co0·2Mn0.2)O2 (NCM622) cathode materials were prepared by sol-gel method, and Ce4+ modification was utilized to improve cycling stability and rate performance. Through XRD refinement, XPS, SEM and TEM characterization, it was found that in the case of 0.5 at% level, Ce4+ ions not only entered into the crystal lattice to replace transition metal ions, but also produced CeO2 coating on the surface of NCM622 particles. The results of electrochemical performance showed that after 100 cycles at 1 C rate, the capacity retention of NCM-0.5 sample increased by 11.03% compared to pristine sample. Besides, in the case of 5 C, the capacity of NCM-0.5 sample reached to 114.92 mAh·g−1, much higher than that of NCM-0 (91.92 mAh·g−1). The findings indicate that it is the synergistic effect of Ce4+ that endows NCM622 excellent cycling stability and rate performance at high cut-off voltage.

During quenching of aluminium alloys from the solutionising temperature vacancies are partially conserved as excess vacancies, partially lost to vacancy sinks, the exact fractions depending on the cooling rate. Positron lifetime measurements in samples from interrupted quenching experiments reveal that vacancies are lost during cooling down to 200 °C, after which solute atoms start to form clusters down to 20 °C. Slow cooling leads to 1 to 2 orders of magnitude lower excess vacancies than fast cooling. Since quenched-in vacancies are crucial for natural ageing (NA) in Al-Mg-Si alloys it is surprising to find just small differences between the NA hardening kinetics after different quenches. Specifically, hardening rates differ only in the initial stage (

This study aims to develop a model to characterize the inhomogeneous material deformation behavior in micro-forming. First, the influence of individual grain heterogeneity on the deformation behavior of CuZn20 foils was investigated via tensile and micro-hardness tests. The results showed that different from thick sheets, the hardening behavior of grains in the deformation area of thin foils is not uniform. The flow stress of thin foils actually only reflects the average hardening behavior of several easy-deformation-grains, which is the reason that thinner foils own smaller flow stress. Then, a composite modeling method under consideration of individual grain heterogeneity was developed, where the effects of grain orientation and shape are quantitatively represented by the method of flow stress classification and Voronoi tessellation, respectively. This model provides an accurate and effective method to analyze the influence of individual grain heterogeneity on the deformation behavior of the micro-sized material.

Kernel moisture content is an important factor in mechanized corn harvesting. However, the rapid and nondestructive in situ detection of the kernel moisture content within an intact corn ear in the field remains challenging. In this work, we designed a novel handheld device with a double-ring sensing probe for nondestructive and convenient kernel moisture detection in intact corn ears based on an active reflection bridge operating in the radio frequency range. By proposing an equivalent first-order resistor–capacitor impedance model for a load composed of a corn ear and the double-ring sensing probe, we found that the reflection coefficient’s phase angle $\theta $ was monotonic with the moisture content and also found that the measurement signal frequency affected the corn grain moisture measurement sensitivity. Before using the handheld device in the field, we investigated its optimal signal frequency range and the effects of temperature variations on the measurement results. In the frequency range of 140–165 MHz, the measured voltages from the device showed a good linear relationship and high sensitivity with respect to both the dielectric constants and the corn ear temperature (9 °C–22 °C). Using this device at a signal frequency of 160 MHz, we conducted corn ear moisture measurements in a total of 73 samples and then established a linear model. The results showed that, for corn ear moisture contents in the range of 15.7%–31.5%, the R values of the training set and the prediction set were 0.7027 and 0.8317, respectively, with a prediction error of 3.54% at the 95% confidence interval.

In certain field conditions such as offshore projects under wave loads or embankments under traffic loads, both the vertical and horizontal stresses are variable. However, previous investigations rarely considered the variation in horizontal stress. To better understand the characteristics of natural saturated soft clay, a series of monotonic and cyclic triaxial tests with a K0-consolidation state were carried out under a variable confining pressure (VCP) stress path. The development of axial strain, pore water pressure and effective stress path is analysed. The results show that with the increase in η (the ratio of the variation in the mean effective principal stress to that of the deviatoric stress), the undrained shear strength (qf) decreases continuously. The pore water pressure generation is slightly improved under a stress path with increasing confining pressure. Based on the test results, a unified formula was established to predict the pore water pressure under VCP stress paths. The unique p–q–e relationship of normally consolidated clay in monotonic VCP triaxial tests was also demonstrated. Under VCP stress paths, the amplitude of the pore pressure increases, and the effective stress path tilts more sharply to the right. Moreover, a unified formula was established that can provide a good reference for predicting effective stress paths under cyclic VCP triaxial tests.

Polycaprolactone coated with chitosan microspheres have the potential to be used as delivery systems and biosensors. Polycaprolactone (PCL) is, however hydrophobic, to improve the biofunctional and potential immobilization of PCL polymer, chitosan-coated PCL microspheres (MSs) were prepared using a double emulsion solvent evaporation method. Different particle sizes were prepared by altering five parameters. When the MSs were prepared using oil to water phase ratio or oil fraction (ϕo) of ϕo = 0.95 to ϕo = 0.38, the MSs average diameter (Dv) reduced from 3.86 to 3.53 µm along with its coefficient of variation (CV), reduced from 18.1 to 12.3 respectively. The MSs prepared with higher polymer concentration of 6wt.% shows higher Dv (4.51 µm) and CV (25.2) compared to 1.2wt.% of PCL, which Dv = 3.86 µm with CV of 18.1. The first homogenizer speed (H1) was increased in order to prepare smaller MSs. When H1 increased from 6 000 to 10 000 rpm, MSs Dv reduced from 3.86 to 3.45 µm along with its CV reduce from 18.1 to 16.6 for ϕo = 0.95. It is also the same case for ϕo = 0.52, where the Dv reduced from 3.70 to 3.19 µm and its CV reduce from 25.8 to 25.2. The effect of NaCl concentration on MSs preparation shows, higher NaCl concentration (1.8wt.%) produced smaller Dv(Dv = 3.86 µm) compared to lower concentration of 0.9wt.%, produced Dv = 4.51 µm for ϕo = 0.95. The trend also follows when the MSs were prepared for ϕo = 0.52. The delay in adding the NaCl shows distinct effect on Dv. For both 0.9 and 1.8 wt.% of NaCl, the Dv increase from 4.51 to 6.40 µm and 4.31 to 6.17 µm respectively. Therefore, the targeted Dv for certain application could be achieved by altering the parameters above. Finally, to study the Ch-PCL potential as enzyme immobilizer, horseradish peroxidase (HRP) was used to be immobilized on to the Ch-PCL MSs. After 7 days, the HRP enzyme still show 51% activity under robust storage condition.

To investigate the electrochemical reduction mechanism of Ta(V) in ethylene carbonate and aluminum chloride (EC−AlCl3) solvate ionic liquid, cyclic voltammetry experiments were conducted on a tungsten working electrode. Four reduction peaks were observed in the cyclic voltammogram of the EC−AlCl3−TaCl5 ionic liquid. The reduction peaks at −0.55, −0.72, and −1.12 V (vs Al) were related to the reduction of Ta(V) to tantalum metal by three stages including the formation of Ta(IV) and Ta(III) complex ions. The reduction of Ta(III) to tantalum metal was an irreversible diffusion-controlled reaction with a diffusion coefficient of 3.7×10−7 cm2/s at 323 K, and the diffusion activation energy was 77 kJ/mol. Moreover, the cathode products at 323 K were characterized by scanning electron microscopy, energy-dispersive spectroscopy, and X-ray photoelectron spectroscopy. The results showed that tantalum metal and tantalum oxides were obtained by potentiostatic electrodeposition at −0.8 V for 2 h.

Z-scheme heterojunction research has become a hotspot in the field of photocatalysis owing to the strong oxidative and reductive capacity for driving photocatalytic reactions. In this work, for the first time, a Z-scheme ternary bismuth phosphate/reduced graphene oxide/protonated g-C3N4 (BiPO4/rGO/pg-C3N4) photocatalyst was fabricated for photocatalytic degradation of tetracycline (TC). The optimal mass ratios of rGO and pg-C3N4 were confirmed as 1.2 wt% and 40 wt%, respectively. This Z-scheme heterojunction exhibited an enhanced TC degrading ability with an 80.0% of TC decomposition after 50 min simulated solar light irradiation, which was 3.3 and 6.3 times that of pg-C3N4 and BiPO4, respectively. Importantly, the internal electric field forced Z-scheme charge transfer of BiPO4/rGO/pg-C3N4 composites, possessing higher charge separation efficiency. The formation of the Z-scheme heterojunction was substantiated by radical scavenging experiments and Mott–Schottky measurements, and it was beneficial for the photocatalytic reaction by accelerating the charge separation and improving the redox ability. Moreover, rGO as cocatalyst could not only provide TC adsorption and catalytic sites but also further promote the charge transfer.

In this study, a drop weight testing method was employed to investigate the impact bending behavior of ethylene vinyl acetate (EVA) modified engineered cementitious composite (ECC). The ECC with no EVA was selected as control, and the static and impact bending behavior was compared with the EVA modified ECC. The results showed that the compressive strength of EVA modified ECC decreased by 20%~30% in comparison with control ECC with fly ash substitution ratio variation. The addition of EVA can improve the bending toughness of ECC dramatically under static loading condition. As different from the static bending, the impact bending toughness of EVA modified ECC was smaller than that of control under impact loading condition. However, the degree of damage of EVA modified ECC was lower than control due to small crack width.

Large-scale CO2 capture through membrane separation is the only viable method for cost-effective emission reduction. However, the fabrication of CO2 separation membranes with sufficient flux and se...

New diamine, 4-(4-diphenylphosphino)phenyl-2,6-bis(4-aminophenyl)pyridine, was prepared, and the related polyamides (PAs) bearing 2,6-diphenylpyridyl units and pendant diphenylphosphinophenyl groups were synthesized by direct polycondensation of this diamine and various aromatic diacids in N-methyl-2-pyrrolidinone (NMP) using triphenyl phosphite and pyridine as condensing agents. The resulting PAs with inherent viscosities of 0.78–1.06 dL g−1 are readily soluble in polar aprotic solvents such as NMP, N, N-dimethylacetamide, and dimethylsulfoxide as well as less polar solvents such as m-cresol and pyridine. All the PAs are amorphous and could be solution-cast into transparent, flexible, and tough films, which have tensile strengths of 68.2–88.8 MPa, tensile moduli of 1.9–2.4 GPa, and elongations at break of 5.4–10.3%. These polymer films also exhibit high optical transparence with the UV cutoff wavelength in the 361–412 nm range. These PAs display glass transition temperatures of 316–332°C, 10% mass loss temperatures of 524–553°C, and more than 48% residues at 800°C in nitrogen, respectively. Their high char yields and good limited oxygen index values ranging from 39 to 44 indicate the prepared PAs show good thermal stability and flame-retardant property.

4-(4-Diphenylphosphino)phenyl-2,6-bis(4-hydroxyphenyl)pyridine, as a new bisphenol monomer, was prepared from 4-(diphenylphosphino)benzaldehyde and 4-hydroxyacetophenone and used in the preparation of several aromatic poly(ether ketone)s (PEKs) containing 2,6-diphenylpyridyl units and diphenylphosphinophenyl pendant groups via a nucleophilic aromatic substitution polycondensation with difluorinated aromatic ketones. The polycondensation proceeded quantitatively in tetramethylene sulfone in the presence of anhydrous potassium carbonate and afforded the polymers with high molecular weights. The resulting PEKs are amorphous and exhibit high glass transition temperatures of 209–255°C and 5% weight loss temperatures of 536–554°C with char yields of 57–62% at 800°C in nitrogen. Their high char yields and good limited oxygen index values ranging from 39 to 43 indicated these polymers exhibited good thermal stability and flame-retardant property. All new PEKs were soluble in common organic solvents such as N-methyl-2-pyrrolidone, N,N-dimethylacetamide, and chloroform and could form tough, flexible, and strong films with tensile strengths of 74.6–86.8 MPa, tensile moduli of 2.9–3.6 GPa, and elongations at break of 5–9%.

Flexible wearable electronics, including monitors, supercapacitors, sensors and batteries, especially stress or strain sensors, have attracted extensive discussion and attention, due to their distinctive characteristics such as high sensitivity and ultra-flexibility, and their broad application prospects in artificial intelligence (AI), robot sensing interfaces, and also high precision medical instruments. However, a narrower deformation rate, higher latency, and even counterfeit sensitivity severely limit their sensing performance and popularity in practical applications. Herein, a new bifunctional sensor based on excellent conductive and biocompatible porous copper nanowire (CuNW)/IonGel (PCI) composite films introducing a polystyrene (PS) microsphere template is developed. The sensor exhibits unparalleled mechanical properties (the maximum extension rate is 8000%), as well as omnidirectional, arbitrary angle/dimension extension, distortion and bending. This piezo-resistive sensor also features a convincing ultra-high sensitivity (S, 72.1 kPa−1) and gauge factor (Gf, 28.5) with negligible hysteresis under repeated cycle tests. Furthermore, compared to the same type of sensor, the limit of detection (LOD) is drastically reduced (merely 0.14 Pa). Undoubtedly, it is promising for high-resolution strain/stress-sensing electronic skin (e-skin) and green super-stretched electrodes.

Oxidative degradation of ultrahigh molecular weight polyethylene (UHMWPE) bearings is one of the main factors that deteriorates their mechanical properties and abrasive wear resistance, which further results in the failure of total joint replacements. Absorption and diffusion of synovial fluids have been considered as causes of the oxidation of UHMWPE bearings. However, the role of synovial fluids in oxidation of UHMWPE remains elusive. In this work, we aimed to reveal the oxidation mechanism of UHMWPE joints with respect to squalene (a representative component of the synovial fluid). The UHMWPE doped in squalene showed slight oxidation, while severe oxidation was observed when squalene doped UHMWPE was exposed to oxygen atmosphere. Squalene manifested lipid peroxidation with notable oxidation products and oxygen-derived free radicals during thermo-oxidative aging. Lipid peroxidation was deduced to follow two routes including autoxidation and thermal oxidation. The aggressive free radicals of squalene abstracted hydrogen atoms from the UHMWPE chains, initiating the oxidation of UHMWPE artificial joints. These findings not only provide evidence for comprehending the process of squalene-induced UHMWPE oxidation but also are instructive to develop highly oxidative-resistant UHMWPE.

Harvesting high-energy excited-state energy is still challenging in organic chromophores. An introduction of boron atoms along the short axis of the diazapentacene backbone induces multiple emission characteristics. Our studies reveal that the weak molecular orbital (MO) coupling of the S3-S1 transition is responsible for the slow internal conversion rates. Such MO coupling-regulated anti-Kasha emission is different from the large band gap-induced anti-Kasha emission character of classical azulene derivatives. Theoretical studies reveal that a strong MO coupling of the S3-S0 transition is responsible for the higher photoluminescence quantum yield of the anti-Kasha emission in a more polar solution (tetrahydrofuran: 11%; cyclohexane: 0%). Such an MO coupling factor is generally overlooked in anti-Kasha emitters reported previously. Furthermore, the multiple emission can be regulated by solvent polarity, solvent temperature, and fluoride anion binding. As a proof of concept of harvesting high-energy emission, the multiple emission character has allowed us to design single-molecule white-light-emitting materials.

WCoB based cermets were prepared by spark plasma sintering at sintering temperature among 600°C-1200 °C. The phase evolution was investigated by detecting density behavior, phase composition, microstructure and mechanical properties during sintering process. The sintering process can be divided into three stages: powder densification, solid phase reaction and liquid phase sintering. WCoB hard phase forms at 1000 °C during solid phase sintering, showing better mechanical properties than Co2B, especially on Vicker's hardness. WCoB hard phase forms on the basis of Co2B binary boride and its content increases in liquid phase sintering stage with high density. The Vicker's hardness and transverse rupture strength (TRS) reach the maximum value of 1262 Hv and 1212 MPa at 1200 °C and 1170 °C, respectively. The fracture toughness reaches the maximum value of 21.8 MPa m1/2 at 1050 °C, and the inter-granular fracture is the main fracture mechanism.

A rotational piezoelectric energy harvester is an electromechanical device that converts ambient mechanical rotation into electric power. The gravity-based method of using the gravity to excite the cantilever beam to deform in the vertical plane has received great attention. The harvester operates effectively at a narrow frequency band, which must be matched with the excitation frequency. For micro applications, low-frequency harvesters are often very difficult to design due to the specific limitations of the size and weight and the thickness of the piezoelectric material. Moreover, low-frequency harvesters require high precision in production and assembly, and small errors can cause large frequency error deviations. In response to this problem, this paper proposes a scheme for designing low-frequency rotational piezoelectric energy harvester, wherein the tuning is accomplished by changing the distance between the mass and the center of rotation. Furthermore, the paper establishes a theoretical model and presents a relationship for frequency adjustment. The experimental results achieved with a piezoelectric fiber composite fit the theoretical results well. The simulation and experimental results show that the resonance frequency of the harvester could be decreased by 63% when the distance between the mass and the center is five times the length of the harvester.

All-inorganic cesium halide perovskite materials are intensively investigated due to their excellent photoelectric characteristics, but poor film coverage, unbalanced charge carrier transporting and insufficient exciton harvesting are remaining challenges to be overcome in order to achieve high electroluminescent (EL) performance in perovskite light-emitting diodes (PeLEDs). Here we show that these problems can be solved by introducing both a phosphorescent sensitizer (FIrpic) and an electron transporting material (TmPyPB) into all-inorganic cesium halide perovskite (CsPbBr3). And highly efficient green PeLEDs with full coverage CsPbBr3:TmPyPB:FIrpic film as the emissive layer have been achieved, exhibiting the maximum luminance of 37784 cd/m2, the maximum current efficiency of 22.6 cd/A and the corresponding maximum external quantum efficiency (EQE) of 5.85%, where the EQE is 48-fold to that of bare CsPbBr3 PeLEDs. The enhanced EL performance is attributed to less non-radiative current leakage, better film surface passivation effect, balanced charge carrier injection and transportation, as well as better exciton harvesting. It is believed that our work will provide an effective strategy to further improve EL performance of PeLEDs via better exciton harvesting.

Cobalt sulfides (including CoS, CoS2, Co3S4, Co9S8 and nonstoichiometric Co1−xS) are deemed to a kind of novel anode material for lithium ion batteries due to their large specific capacities. However, cobalt sulfides suffer from poor cycling stability with the large volume expansion. In this work, we designed and synthesized a novel Co-metal organic frameworks (MOFs) material by using carbazolyl carboxylates ligand H4DCDC. The Co1−xS nanoparticles embedded in N-doped carbon sheets (Co1−xS/NCS) composites are obtained via vulcanizing the Co-MOFs precursor. As a result, the Co1−xS/NCS exhibits outstanding cycling stability and maintains a high capacity of 796.3 mA h g−1 at the current density of 200 mA g−1 after 100 cycles. The N-doped carbon sheets can not only enhance the conductivity of materials but also buffer the volume expansion during charge-discharge process.

The solution-processed all-inorganic cesium lead halide perovskite material have attracted significant attention because of their high color purity, low cost, high thermal stability, high photoluminescence quantum yield. However, the low internal quantum efficiency immensely confine their application in display. In our work, we utilized an ultrathin buffer layer of the thermal activation delayed fluorescence (TADF) material 4,5-bis(carbazol-9-yl)− 1,2-dicyanobenzene (2CzPN), which can realize 100% internal quantum efficiency, to make an efficient Fӧrster energy transfer for the energy of excitons on 2CzPN to be transferred to the excited state of CsPbBr3. A CsPbBr3 perovskite light-emitting diode (PeLED) with an optimized ultrathin 2CzPN buffer layer exhibited improved electroluminescence (EL) performance with lower turn on voltage of 3.6 V, the maximum luminance of 7660 cd/m2, the maximum current efficiency of 2.83 cd/A, which are 7-fold and 5.5-fold compared to that of the conventional PeLED without the ultrathin buffer layer.

B and N co-doped SiC nanopowders were prepared by combustion synthesis under a nitrogen atmosphere from the Si/C system, using α-Si3N4 powder and B powder as solid nitriding agent and dopant, respectively. The prepared particles had spherical morphology and narrow size distribution. XPS analysis demonstrated that B and N atoms successfully incorporated into SiC crystal and formed Si1-xBxC1-yNy solid solution. Results of dielectric properties showed that the real part e′ and imaginary part e″ of the complex permittivities of the samples decreased first, and then increased with increasing N content. The sample with 5% B and 15% N revealed the greatest values in e′ and e″ and better microwave absorption performance. The corresponding mechanism of the dielectric properties of SiC improved by co-doping was discussed in detail.

Organic contaminants in water have become one of the most serious environmental problems worldwide. Adsorption is one of the most promising approaches to remove organic pollutants from water. However, the existing adsorbents have relatively low removal efficiency, complex preparation processes, and high cost, which limit their practical applications. Here, we developed three-dimensional (3D) zirconium metal-organic frameworks (MOFs) encapsulated in a natural wood membrane (UiO-66/wood membrane) for highly efficient organic pollutant removal from water. UiO-66 MOFs were in situ grown in the 3D low-tortuosity wood lumens by a facile solvothermal strategy. The resulting UiO-66/wood membrane contains the highly mesoporous UiO-66 MOF structure as well as many elongated and open lumens along the direction of the wood growth. Such a unique structural feature improves the mass transfer of organic pollutants and increases the contact probability of organic contaminants with UiO-66 MOFs as the water flows through the membrane, thereby improving the removal efficiency. Furthermore, the integrated multilayer filter consisting of three pieces of UiO-66/wood membranes exhibits a high removal efficiency (96.0%) for organic pollutants such as rhodamine 6G, propranolol, and bisphenol A at the flux of 1.0 × 103 L·m-2·h-1. The adsorbed capacity of UiO-66/wood for Rh6G (based on the content of UiO-66 MOFs) is calculated to be 690 mg·g-1. We believe that such low-cost and scalable production of the UiO-66/wood membrane has broad applications for wastewater treatment and other related pollutant removal.

Simultaneous detection of both ion flux and membrane potential in vivo and in situ in plants is a challenging research task. To explore the mechanisms of plant electrical activity, researchers urgently need to understand and determine the types of ions and the ion fluxes that pass in and out of cells during polarization and repolarization, but the required measurements are very difficult to perform. In this paper, we have developed a versatile system that can detect the ionic flux and the membrane potential, in vivo and in situ , simultaneously. The system uses a self-referencing ion-selective glass microelectrode and a membrane potential glass microelectrode as sensors. These sensors are linked through a preamplifier with high input impedance to a specific dynamic measurement system that can amplify small extracellular concentration gradient signals and realize simultaneous measurement of both the ion flux and the membrane potential. In addition, an interpolation fitting algorithm has been proposed to reduce the artifacts that are present in the in situ measurements during plant growth. The hydrogen ion fluxes in wheat roots were measured using the self-referencing ion-selective microelectrodes, and the proposed system was used to measure NaCl stimulation-induced changes in the membrane potentials and hydrogen ion fluxes of wheat root epidermal cells. The results demonstrate that the system can meet the ion flux and membrane potential measurement requirements.

The root zone of a plant is an important system that provides a base for use of nutrients and water and has been the focus of many researchers’ work. This paper examines a new electrical impedance spectroscopy (EIS) measurement approach within the 100 Hz–2 MHz range in the substrate root zone that uses an adjacent stimulation and measurement pattern that overcomes the shortcomings of conventional methods and better reflects physiochemical changes in stereoscopic space. We used a highly controllable mixed solid substrate to simulate the root zone. The experimental results show that three impedance features, comprising the mean of the real part of the complex impedance within the 1–10 kHz range, the characteristic frequency and the extremum of the imaginary part of the complex impedance are strongly exponentially correlated with the water content of the cylindrical substrate, in which the minimum coefficient of determination denoted by R2 is 0.9247. This indicates that these features can serve as indicators of the substrate’s water content. In addition, the substrate-plant continuum was investigated and we found that the presence of the plant had a strong impact on the impedance response, and particularly on the data from the equipotential contralateral side, which can be used for root zone plant positioning. Additionally, analysis of the variation of the phase angle shows that the position of the plant underground has little effect on the frequency corresponding to the maximum absolute phase difference, which provides a reference for frequency selection in the impedance measurement and tomography system of the substrate root zone. We conclude that EIS can be used to monitor the plant morphology and also provides a way to determine the optimal frequency for impedance measurement.

Perovskite light-emitting diodes (PeLEDs) are promising next-generation light sources due to the excellent optical and electronic properties of the materials as well as their process simplicity and low cost. To boost their electroluminescence (EL) efficiency, a plethora of approaches are proposed and demonstrated. Here, another possibility by introducing an exciton retrieving layer (ERL) into the devices is reported. A composite layer, formed by vacuum co-evaporating an electron transporting material (1,3,5-tri(m-pyrid-3-yl-phenyl)benzene, TmPyPB) and a blue phosphorescent material (bis(2-(4,6-difluorophenyl)-pyridinato-N,C2′)picolinate, FIrpic), is inserted into PeLEDs as an ERL in between the emitting layer and the electron transporting layer. Both 3D and quasi-2D PeLEDs with an ERL exhibit strongly enhanced EL performance without changing the emission spectra. 3D PeLEDs show a low turn-on voltage of ∼3.6 V, a maximum luminance of 14 363 cd m−2, and a maximum external quantum efficiency (EQE) of 1.26%, which correspond to 2.5-fold luminance and 3.8-fold EQE enhancements compared with the control device. Quasi-2D PeLEDs exhibit a low turn-on voltage of ∼3.6 V, a maximum luminance of 9481 cd m−2, and a maximum EQE of 4.24%, corresponding to a 2.7-fold EQE enhancement compared with the control device. The physical mechanism is further discussed theoretically and validated experimentally. The blue phosphorescent FIrpic can act as a sensitizer such that energy can be transferred from both the singlet and triplet excitons of TmPyPB to the excited states of CsPbBr3via Forster and Dexter energy transfer processes.

The past few years have witnessed an impressive development of all-inorganic halide perovskite nanocrystals. In this report, a series of CsPbBrxI3−x nanocrystal/carbon nanotube (CsPbBrxI3−x NC/CNT, x = 3, 2, 1.5, 1) hybrid photoelectrodes have been fabricated and further employed in photoelectrochemical cells. Benefiting from the high conductivity of CNTs, the hybrid samples show accelerated charge separation and transfer actions after photoexcitation. Moreover, increasing the I/Br ratio in CsPbBrxI3−x nanocrystals accounts for a wider adsorption range but inferior phase stability, which calls for a delicate balance. As a result, the highest photocurrent density of 420 μA cm−2 is finally achieved by CsPbBr1.5I1.5 NC/CNT (200), which corresponds to a 7.7-fold improvement over the prototype CsPbBr3. This report offers an in-depth understanding of the charge transfer behavior along with photoelectrochemical performance of CsPbBrxI3−x nanocrystal/CNT, which can surely stimulate metal halide perovskite nanocrystal-based hybrid materials for promising optoelectronic, photocatalysis and photoelectrochemical applications.

Although single-particle cryogenic electron microscopy (cryo-EM) has been applied extensively for elucidating many crucial biological mechanisms at the molecular level, this technique still faces critical challenges, the major one of which is to prepare the high-quality cryo-EM specimen. Aiming to achieve a more reproducible and efficient cryo-EM specimen preparation, novel supporting films including graphene-based two-dimensional materials have been explored in recent years. Here we report a robust and simple method to fabricate EM grids coated with single- or few-layer reduced graphene oxide (RGO) membrane in large batch for high-resolution cryo-EM structural determination. The RGO membrane has decreased interlayer space and enhanced electrical conductivity in comparison to regular graphene oxide (GO) membrane. Moreover, we found that the RGO supporting film exhibited nice particle-absorption ability, thus avoiding the air-water interface problem. More importantly, we found that the RGO supporting film is particularly useful in cryo-EM reconstruction of sub-100 kDa biomolecules at near-atomic resolution, as exemplified by the study of RBD-ACE2 complex and other small protein molecules. We envision that the RGO membranes can be used as a robust graphene-based supporting film in cryo-EM specimen preparation.

Zi-Yang Zhang,1 Lin-Xiao Huang,1 Zhi-Wei Xu,1 Peng Wang,1 Yun Lei,1,2 Ai-Lin Liu1,2 1Department of Pharmaceutical Analysis, The School of Pharmacy, Fujian Medical University, Fuzhou, 350122, People’s Republic of China; 2Higher Educational Key Laboratory for Nano Biomedical Technology of Fujian Province, The School of Pharmacy, Fujian Medical University, Fuzhou, 350122, People’s Republic of ChinaCorrespondence: Yun Lei; Ai-Lin LiuDepartment of Pharmaceutical Analysis, The School of Pharmacy, Fujian Medical University, Fuzhou, 350122, People’s Republic of ChinaTel +86 591 22862016Email lypiglet@163.com; ailinliu@fjmu.edu.cnPurpose: The PML/RARα fusion gene as a leukemogenesis plays a significant role in clinical diagnosis of the early stage of acute promyelocytic leukemia (APL). Here, we present an electrochemical biosensor for PML/RARα fusion gene detection using carbon dots functionalized graphene oxide (CDs/GO) nanocomposites modified glassy carbon electrode (CDs/GO/GCE).Materials and Methods: In this work, the CDs/GO nanocomposites are produced through π-π stacking interaction and could be prepared in large quantities by a facile and economical way. The CDs/GO nanocomposites were decorated onto electrode surface to improve the electrochemical activity and as a bio-platform attracted the target deoxyribonucleic acid (DNA) probe simultaneously.Results: The CDs/GO/GCE was fabricated successfully and exhibits high electrochemical activity, good biocompatibility, and strong bioaffinity toward the target DNA sequences, compared with only the pristine CDs on GCE or GO on GCE. The DNA biosensor displays excellent sensing performance for detecting the relevant pathogenic DNA of APL with a detection limit of 83 pM (S/N = 3).Conclusion: According to the several experimental results, we believe that the simple and economical DNA biosensor has the potential to be an effective and powerful tool for detection of pathogenic genes in the clinical diagnosis.Keywords: acute promyelocytic leukemia, pathogenic genes, electrochemical biosensor, ex-situ method, carbon nanomaterials

Objective To investigate the biomechanical effects of different insertion angles of absorbable screws for the fixation of radial head fractures. Methods The finite element models used to simulate the fractures were created based on CT scans. Two absorbable screws were used to fix and maintain the stability of the fracture, and the angles between the screws were set to 0°, 15°, 30°, 45°, 60°, 75°, and 90°. A downward force of 100 N was applied at the stress point, which was coupled with the surface, and the distal radius was limited to six degrees of freedom. The direction and location of the applied force were the same in each model. The values of the von Mises stress and peak displacements were calculated. Results Under the applied load and different screw angles, the maximum von Mises stress in the screws was concentrated on the surface contacting the fracture surfaces. The maximum von Mises equivalent stress in the screw decreased when the angle increased from 0° (19.54 MPa) to 45° (13.11 MPa) and increased when the angle further increased to 90° (24.63 MPa). The peak displacement decreased as the angle increased from 0° (0.19 mm) to 45° (0.15 mm) and increased when the angle further increased to 90° (0.25 mm). Conclusion The computational stress distribution showed that fixation with absorbable screws is safe for patients. Moreover, the minimum von Mises stress and displacements were generated when the angle between the screws was 45°; hence, this setting should be recommended for Mason type II radial fractures., This current study uses a finite element model to study the influence of absorbable screw designs in type II radial fractures. The 45° angle between two screws provided the optimal biomechanical effect, and generated wider stress distribution, and the minimum stress and displacement in screw fixation.

Twisted bilayer graphene (TBG) provides a unique framework to elucidate the interplay between strong correlations and topological phenomena in two-dimensional systems. The existence of multiple electronic degrees of freedom -- charge, spin, and valley -- gives rise to a plethora of possible ordered states and instabilities. Identifying which of them are realized in the regime of strong correlations is fundamental to shed light on the nature of the superconducting and correlated insulating states observed in the TBG experiments. Here, we use unbiased, sign-problem-free quantum Monte Carlo simulations to solve an effective interacting lattice model for TBG at charge neutrality. Besides the usual cluster Hubbard-like repulsion, this model also contains an assisted hopping interaction that emerges due to the non-trivial topological properties of TBG. Such a non-local interaction fundamentally alters the phase diagram at charge neutrality, gapping the Dirac cones even for infinitesimally small interaction. As the interaction strength increases, a sequence of different correlated insulating phases emerge, including a quantum valley Hall state with topological edge states, an intervalley-coherent insulator, and a valence bond solid. The charge-neutrality correlated insulating phases discovered here provide the sought-after reference states needed for a comprehensive understanding of the insulating states at integer fillings and the proximate superconducting states of TBG., 15 pages, 9 figures, 2 tables

Heavy metal pollution is a severe problem worldwide. Great efforts have been devoted in developing effective and eco-friendly ways to remove heavy metal ions from contaminated water. However, challenges remain in terms of the high cost, the complex preparation processes required, low efficiency, and difficulties in scaling-up. Here, we report a sulfhydryl-functionalized wood (SH-wood) membrane featuring three-dimensional mesoporous and low-tortuosity lumens, which serve as multisite metal traps to achieve highly efficient heavy metal ion removal from wastewater. Benefiting from the unique microstructure of wood, the resulting membrane exhibits a high saturation uptake capacity of 169.5, 384.1, 593.9, and 710.0 mg·g-1 for Cu2+, Pb2+, Cd2+, and Hg2+ ions, respectively. Meanwhile, the SH-wood membrane can be easily regenerated at least eight times without apparent performance loss. Furthermore, stacking multilayers of the SH-wood filter is designed. Because of its high yet universal heavy metal ion absorbance capability, the multilayer SH-wood filter can effectively remove diverse heavy metal ions from real contaminated water, meeting the WHO standards while also displaying a high flux rate of 1.3 × 103 L·m-2·h-1. Our work presents a promising strategy for the scalable and highly efficient removal of heavy metal ions from sewage for environmental remediation.

The fast development of high-resolution electron microscopy (EM) demands a background-noise-free substrate to support the specimens, where atomically thin graphene membranes can serve as an ideal candidate. Yet the preparation of robust and ultraclean graphene EM grids remains challenging. Here we present a polymer- and transfer-free direct-etching method for batch fabrication of robust ultraclean graphene grids through membrane tension modulation. Loading samples on such graphene grids enables the detection of single metal atoms and atomic-resolution imaging of the iron core of ferritin molecules at both room- and cryo-temperature. The same kind of hydrophilic graphene grid allows the formation of ultrathin vitrified ice layer embedded most protein particles at the graphene-water interface, which facilitates cryo-EM 3D reconstruction of archaea 20S proteasomes at a record high resolution of ~2.36 Å. Our results demonstrate the significant improvements in image quality using the graphene grids and expand the scope of EM imaging., High-resolution electron microscopy requires robust and noise-free substrates to support the specimens. Here, the authors present a polymer- and transfer-free direct-etching method for fabrication of graphene grids with ultraclean surfaces and demonstrate cryo-EM at record high resolution.

We systematically study the low-temperature specific heats for the two-dimensional kagome antiferromagnet, Cu$_{3}$Zn(OH)$_6$FBr. The specific heat exhibits a $T^{1.7}$ dependence at low temperatures and a shoulder-like feature above it. We construct a microscopic lattice model of $Z_2$ quantum spin liquid and perform large-scale quantum Monte Carlo simulations to show that the above behaviors come from the contributions from gapped anyons and magnetic impurities. Surprisingly, we find the entropy associated with the shoulder decreases quickly with grain size $d$, although the system is paramagnetic to the lowest temperature. While this can be simply explained by a core-shell picture in that the contribution from the interior state disappears near the surface, the 5.9-nm shell width precludes any trivial explanations. Such a large length scale signifies the coherence length of the nonlocality of the quantum entangled excitations in quantum spin liquid candidate, similar to Pippard's coherence length in superconductors. Our approach therefore offers a new experimental probe of the intangible quantum state of matter with topological order., Comment: 6 pages, 3 figures

A facile dual-mode optical nanokit for Cu2+ detection has been developed based on a distinctive synergy between ligand-free lanthanide-doped upconversion nanoparticles (UCNPs) and porphyrin hydrate. Oleic acid (OA)-capped β-NaYF4: 20%Yb, 0.5%Tm UCNPs were synthesized and then experienced an acid treatment for the preparation water-dispersible ligand-free UCNPs. The resulting UCNPs can readily combine a commercially available porphyrin hydrate (TPPS) to form UCNPs/TPPS complex, showing a green color from TPPS and low upconversion fluorescence of UCNPs quenched by TPPS due to fluorescence resonance energy transfer (FRET). The as-prepared UCNPs/TPPS can further combine Cu2+ into its cavity through the Cu2+-TPPS bonding. Then, a distinctive synergy between UCNPs and TPPS would be generated including the Cu2+-regulated color change of TPPS and its concomitant inhibiting effect on the preceding FRET, thus giving rise to an obvious color change from green to pink and a simultaneous enhancement of the upconversion fluorescence of UCNPs. Because of such distinctive synergy, UCNPs/TPPS has been demonstrated to be a novel dual-mode colorimetric and fluorometric nanokit for Cu2+ monitoring with high sensitivity and selectivity. Moreover, coupled with our proposed colorimetric nanokit, a realtime quantitative sensing has been also presented by using a smartphone with easy-to-access color-scanning APP as the detection platform.

In this report, a novel zero-dimensional CsPbBr3 nanocrystal (CsPbBr3 NC)/two-dimensional Pd nanosheet (Pd NS) composite photocatalyst is prepared to afford efficient and stable photocatalytic gaseous CO2 reduction in the presence of H2O vapor under visible light illumination. Pd NS herein acts as an electron reservoir to quickly separate the electron–hole pairs in CsPbBr3 NC through a Schottky contact, and provides an ideal site for CO2 reduction reactions. A highest electron consumption rate of 33.79 μmol g–1 h–1 is achieved by the CsPbBr3 NC/Pd NS composite, which corresponds to a 2.43-fold enhancement over pristine CsPbBr3 NC (9.86 μmol g–1 h–1), thus providing a practical and universal solution for the halide perovskite materials to boost the photocatalytic performance through semiconductor/metal design.

CO 2 transcritical cycle has been widely applied in commercial refrigeration and heat pump water heating systems. Its cycle COP (coefficient of performance) heavily depends on the high pressure optimization and control. In theory, the optimal high pressure increases quickly with the increasing gas cooler outlet temperature or ambient temperature. However, due to reliability and cost concerns, there is an upper limit of the high pressure in compressor design and system operation. In this work, we proposed a constrained optimization method for getting constrained optimal high pressure equation of CO 2 transcritical cycle. With the new method, the high pressure and its upper bound were simultaneously optimized at a given level of COP loss. Two specific approaches were developed to get the constrained optimal high pressure equation. Up to 1 MPa high pressure reduction was achieved with about maximum 5% and average 1% COP losses.

Bi2(Se0.1Te0.9)3and Ni are the most commonly used N-type thermoelectric material and barrier layer in commercial thermoelectric modules. This study systematically examines the interfacial reactions between Ni and Bi2(Se0.1Te0.9)3and its constituent material systems. Results related to the interfacial reactions between Ni/Se and Ni/Bi2Se3 are not available in the literature, and are reported for the first time in this study. The reaction phases in the solid/solid Ni/Bi, Ni/Se, Ni/Bi2Te3 and Ni/Bi2(Se0.1Te0.9)3 couples are NiBi3, α-Ni3Se2 and Ni1-xSe, NiTe2 and (Bi2)m(Bi2Te3)n, and NiTe2 and (Bi2)m(Bi2Te3)n, respectively. The reaction phases in the solid/solid Ni/Te and Ni/Bi2Te3 couples evolve with reaction time. Respectively, they are NiTe2 and Bi-oversaturated Ni1-xSe phase in the early stage of reaction, and become Ni3Te2, NiTe0.775 and NiTe2, and NiBi3 and Ni1-xSe phases with longer reaction time. The Ni/Te reaction rate is slower compared with those of Ni/Bi and Bi/Se, yet the dominant reaction phase is the NiTe2 phase in both the Ni/Bi2Te3 and Ni/Bi2(Se0.1Te0.9)3 couples.

The evolution of microstructure and microhardness was studied in a commercial tungsten-25% rhenium (mass fraction) (W-25Re) alloy processed by the high pressure torsion (HPT) procedure under a pressure of 7.7 GPa up to 10 revolutions at different temperatures. The results show that the samples processed by 10 revolutions at room temperature could have the smallest grain size at around 0.209 μm. High saturation hardness (HV ∼1200) could be achieved after the rapid strengthening stage for samples processed by 10 revolutions both at room temperature and at 573 K. Microstructural observation and analysis from Hall–Patch relationship could reveal that grain refinement and grain boundaries strengthening are the main factors of hardening mechanism in W-25Re alloy. It is also demonstrated that sintered W-25Re sample may have brittle phase separation phenomenon after HPT processing.

In this study, natural aggregates were replaced with reclaimed asphalt pavement (RAP) from a basic oxygen furnace (BOF) and applied to the base or subbase of roads. The effects of using different levels of RAP BOF to replace the natural aggregates on the properties of the road were investigated. Mixtures of natural aggregates with different contents of RAP BOF (containing 60% BOF slag) aggregates were used, and the results indicate that using a RAP BOF aggregate content up to 40% in the road base satisfies the requirements for the California bearing ratio (CBR) and expansion ratios. The study suggests that the optimal RAP BOF aggregate replacement content is 20%.

The tunable and high levels of reversible or actuation strains are important for the application of reversible shape-memory polymers (RSMPs) as actuators. Here, temperature-memory polymer actuators based on semicrystalline networks exhibiting a broad melting temperature range are presented. The relationship between the programing temperature (Tprog), applied actuation temperature (Tact) and actuation strains is explored. The actuation strains increase first and then decrease with the elevated Tact, showing the maximum actuation strain when Tact is roughly the same as the Tprog. The contraction force is also found to show the maximum nearly at the Tprog. The exactly same temperature memory effect of reversible deformation and contraction force arises from the gradually activating of actuation domain below Tprog and softening of skeleton domain above Tprog, resulting highly tunable reversible deformation based on temperature memory. This work provides the design criteria for tuning the reversible strain of semicrystalline networks based on the temperature memory effect, and the custom-designed actuator shows potential applications in the field of anti-counterfeiting.