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In this study, we propose the production of a thin-film composite (TFC) membrane with efficient antimicrobial properties by modifying it with cellulose nanocrystals (CNC) and silver nanoparticles (AgNP). Two approaches (i.e., “one-pot” and “layer-by-layer”) were employed to incorporate CNC and AgNP onto the membrane surface and their impact on the membrane antimicrobial properties was examined. Firstly, the “one-pot” method involved reacting CNC with AgNO3and NaBH4to form a CNC/Ag hybrid material. This CNC/Ag hybrid was then applied to the TFC drawmembranes using polydopamine (PDA) chemistry, allowing the deposition of both CNC and AgNP in a single step. Secondly, the “layer-by-layer” method involved attaching CNC to the membrane surface using PDA chemistry, which was then followed by an in situreaction of AgNO3and NaBH4to deposit the AgNP directly on top of the CNC layer. Membranes modified with a CNC/Ag hybrid using the one-pot method were able to deactivate 75.7 ± 15.6% of attached E. colicells without detrimental impact to membrane separation performance. The membranes modified using the layer-by-layer assembly demonstrated improved antimicrobial activity when compared to those modified with the one-pot CNC/Ag hybrid, being capable of inactivating 90% of the attached E. colicells. On the other hand, the layer-by-layer modification method led to a significant loss in the membrane's salt rejection capacity. These water-based, straightforward, and simple functionalization strategies can tailor the antimicrobial and anti-biofouling performance of membranes for water treatment applications.

ABSTRACTThis paper aims at investigating influencing factors of block chain on collaborative product innovation (CPI) performance in the manufacturing supply chain. First, according to the application value of block chain in CPI and the CPI characteristics in manufacturing SC, this paper proposes a research model based on the innovation diffusion theory. Second, a set of hypotheses were derived from the research mode and a questionnaire was deployed to collect data in Chinese manufacturing enterprises. Data analysis was performed by using the AMOS modeling method based on a total of 373 valid surveys. Findings show a positive linear chain relationship between block chain, supply chain’s collaborative innovation capability, and supply chain’s CPI performance. Moreover, block chain capability is diffused into CPI capability for indirectly promoting the supply chain’s CPI performance. This study can put forward theoretical guidelines for manufacturing enterprises to grasp the strategic significance of block chain in product innovation activities.

ABSTRACTThis paper identifies risk factors in the smart supply chain and develops a risk assessment index system for reducing potential losses in intelligent manufacturing. Specifically, based on the supply chain operation reference theory, we investigate the performance indicators and characteristics of the smart supply chain in intelligent manufacturing in China. A conceptual model for identifying risks of the smart supply chain is developed, and a questionnaire is designed to measure the risks of the smart supply chain in intelligent manufacturing. Using the hierarchical clustering analysis, an improved risk assessment model is derived with 22 risk factors based on 814 valid sample data. Moreover, the information entropy weight method is used to compute the risk weights for the smart supply chain in intelligent manufacturing. The risk weights are further verified by simulation and proved that these risk factors and risk weights have high practical efficiency. Theoretical and practical implications are also presented.

Ammonium salt vanadium precipitation is the main method of vanadium metallurgy at home and abroad, but the traditional ammonium precipitation of vanadium can only obtain high valence of V2O5, and the NH3produced in the calcination process cannot be fully utilized. And the preparation of low-valence vanadium oxide V2O3is long and costly. Self-reduction of thermal decomposition of nitrogen-containing precipitation products to produce V2O3is a novel and short process method that can achieve full utilization of ammonia. NaVO3was used as the vanadium source, choline chloride (C5H14ClNO (ChCl)) was used as the vanadium precipitation reagent, and the vanadium concentration was 30 g/L, n(ChCl)/n(V) = 1.5, the initial pH was 1.5, the temperature was 85°C, the time was 2 h, and the vanadium precipitation efficiency could reach 97.05%. V2O3with purity of 97.98% can be obtained by calcination at 550°C for 3 h in an argon atmosphere. XRD, FTIR, XPS, SEM-EDS were used to characterize the product, which further proved that the final product was V2O3. The electrocatalytic hydrogen evolution reaction (HER) of V2O3in acidic media showed high stability after 1000 cyclic voltammetry (CV) cycles, with a low Tafel slope of 88.5 mVdec−1. The electrochemical double layer capacitance (EDLC) was measured by CV at different scan rates, and the EDLC of V2O3was 1.104 mFcm−2. This study provides a short-flow preparation method for V2O3and can provide predictions for the application of V2O3in HER and supercapacitors.

Microscale swimmers are attractive for targeted drug delivery, noninvasive microsurgery and environmental remediation at different length scales, among which, Marangoni-based swimmers have garnered considerable attention due to their independence of external energy supply. However, applications of most existing chemical swimmers are limited by complex fabrication, high cost, utilization of organic (or even toxic) solvents, poor motility performance, and lack of controllability. To address these challenges, we propose an approach for all-aqueous soft milli-swimmers that utilizes biodegradable hydrogels and biocompatible fuels. This innovative method achieves swimmer body generation and fuel loading in one step by simply dripping one aqueous solution into another, saving fabrication time and minimizing fuel loss during transfer. These all-aqueous soft milli-swimmers have rove beetle-like self-propulsion, which stores low-surface-energy compounds within their body for propulsion on liquid surfaces. Isotropic and anisotropic all-aqueous soft milli-swimmers are formed with precise control over their dimension, morphology, and movement velocity. Through their motion within engineered channels, intricate labyrinths, dynamic air−liquid interfaces, and collective self-assemblies, their remarkable adaptability in complex aqueous environments is demonstrated. Furthermore, the integration of functional nanoparticles endows these all-aqueous milli-swimmers with multifunctionality, expanding their applications in cargo transportation, sensing, and environmental remediation.

In this study, we propose an intercalated surface modification strategy that combines three important functionalities in thin-film composite (TFC) membranes: 1) resistance to the deposition of organic fouling, 2) anti-biofouling properties in static and cross-flow conditions, and 3) an improved self-cleaning property that reflects the membranes' ability to easily release attached bacteria cells. The membrane functionalization strategy consists of immobilizing a polydopamine (PDA) layer, followed by the intercalation of silver nanoparticles (AgNPs) and poly (sulfobetaine methacrylate) (PSBMA) zwitterionic brushes (PDA–Ag–PSBMA TFC). The presence of zwitterionic PSBMA brushes shields the membrane surface against the non-specific adsorption of fluorescent bovine serum albumin (BSA), demonstrating a superior anti-fouling property. Moreover, the PSBMA brushes impart the TFC membranes with an excellent ability to release attached cells under gentle agitation. AgNPs intercalated between PDA and PSBMA layers, on the other hand, enabled a prolonged anti-biofouling property by efficiently inactivating ∼90% of the attached Pseudomonas aeruginosacells. Dynamic biofouling experiments under a cross-flow condition and confocal laser scanning microscopy (CLSM) imaging show reduced flux decline and inhibition of biofilm formation for PDA–Ag–PSBMA TFC membranes, respectively, confirming the effectiveness of our intercalated surface modification strategy for simultaneous control of organic fouling and biofouling.

The influence of ionic strength on the transport behaviors of natural or engineered colloids has been widely studied in recent years, and the explanatory classical Derjaguin–Landau–Verwey–Overbeek (DLVO) theory has also been employed in many studies. However, ion-specific effects were barely applied to interpret the contradiction between the experimental observations and classical DLVO predictions when nanoparticle or colloidal aggregation and deposition took place in different cationic solutions. In this study, the effects of ionic specificity of the first-group monovalent cations (i.e., Li+, Na+, K+, and Rb+), and the influence of representative polysaccharides (alginate) and proteins (bovine serum albumin (BSA), on the aggregation and deposition behaviors of colloidal manganese dioxide (MnO2) onto silica (SiO2) and iron (Fe3O4) surfaces were systematically studied by employing time-resolved dynamic light scattering (DLS) and a quartz crystal microbalance with dissipation monitoring (QCM-D), respectively. Experimental results indicated that the additive cations with a poorer hydration degree (e.g., Rb+) were more efficient in promoting the aggregation, hindering the deposition kinetics of colloidal MnO2. This could be quantitatively interpreted with the modified DLVO theory, through the introduction of additional short-range repulsion, which was generated from a hydration force between colloids and interfaces. Moreover, BSA was more efficient in hindering the aggregation of colloidal MnO2than alginate. Furthermore, BSA could enhance the deposition of MnO2while alginate exhibited the opposite effect. These results revealed the significance of ionic specificity in the aggregation and deposition behaviors of MnO2colloids and provided insights into understanding the role of counterion hydration in the transport and fate of engineering nanoparticles (ENPs) in an aquatic environment.

The oxidation of the toxic heavy metal thallium(I) (Tl(I)) is an efficient way to enhance Tl removal from water and wastewater. However, few studies have focused on the kinetics of Tl(I) oxidation in water, especially at environmentally relevant pH values. Therefore, the kinetics and mechanisms of Tl(I) oxidation by the common agents KMnO4and HOCl under environmentally relevant pH condition were explored in the present study. The results indicated that the pH-dependent oxidation of Tl(I) by KMnO4exhibited second-order kinetics under alkaline conditions (pH 8–10) with the main active species being TlOH, while the reaction could be characterized by autocatalysis at pH 4–6, and Mn(III) might also play an essential role in the MnO2catalysis. Furthermore, a two-electron transfer mechanism under alkaline conditions was preliminarily proposed by using linear free energy relationships and X-ray photoelectron spectroscopy (XPS) analysis. Distinctively, the reaction rate of Tl(I) oxidation by HOCl decreased with increasing pH, and protonated chlorine might be the main active species. Moreover, the Tl(I)-HOCl reaction could be regarded as first order with respect to Tl(I), but the order with respect to HOCl was variable. Significant catalysis by MnO2could also be observed in the oxidation of Tl(I) by HOCl, mainly due to the vacancies on MnO2as active sites for sorbing Tl. This study elucidates the oxidation characteristics of thallium and establishes a theoretical foundation for the oxidation processes in thallium removal.

This paper analyses the function expression of the optimal minimum competition window which integrates the network node number, average collision data frame length and sending rate of data frame. At the same time, the proposed optimised method of MAC protocol combines with the SVN neural network which can memory communication environment which include node density and mobile velocity. Each terminal node in the network runs proposed MAC protocol optimisation algorithm based on this function expression to adaptive adjust their minimum competition window and back off the optimal value to improve the network performance. The simulation results show that the effort of optimised algorithm in the Ad Hoc system is limited for unsaturated business VANET; but high accuracy and effect of the optimised algorithm in aspects of throughput and transmission delay has improved significantly for saturated business of VANET.

The aggregation and deposition behaviors of colloidal or dissolved black carbon (DBC) with coexisting heavy metals are important to understand the fate of DBC and the associated contaminants in environmental and engineering systems. Time-resolved dynamic light scattering (DLS) and quartz crystal microbalance with dissipation (QCM-D) techniques were employed to study the effect of cation concentration and properties on the aggregation and deposition behaviors of DBC with divalent heavy metals (Pb2+, Cu2+, Cd2+and Zn2+). The aggregation experiments suggested that divalent heavy metals significantly destabilized DBC due to strong complexation and cation–π interaction, and the destabilization ability of these metal cations was related to their electronegativity (critical coagulation concentration (CCC): Pb2+< Cu2+< Cd2+< Zn2+). The deposition experiments indicated that the presence of heavy metals favored the deposition of DBC on a silica surface, which was characterized by a relatively rigid layer in the initial rapid phase and a relatively swollen layer in the subsequent slow phase. Additionally, the initial deposition rate first increased as the cation concentration increased, while a further increase in cation concentration was unfavorable to the deposition process because of the diffusion limitation. Similarly, the deposited film was more rigid at first and then became more swollen with the increase in cation concentration. Notably, the electronegativity of the metal cation dominated its retention ability (critical deposition concentration (CDC): Pb2+< Cu2+< Cd2+< Zn2+) and surface roughness, while the hydration shell thickness had a greater influence on the viscoelastic properties of the deposited film (rigidity of the adlayer: Pb2+> Cd2+> Cu2+> Zn2+). Overall, these results provide new insights into the aggregation and deposition behaviors of DBC with coexisting heavy metals in aquatic solution, which are helpful to understand the fate of DBC and the associated contaminants.

According to a priori knowledge in complex conditions, this paper proposes an unsupervised image segmentation algorithm to be used for clothing images that combines colour and texture features. First, block truncation encoding is used to divide the traditional three-dimensional colour space into a six-dimensional colour space so that more fine colour features can be obtained. Then, a texture feature based on the improved local binary pattern (LBP) algorithm is designed and used to describe the clothing image with the colour features. After that, according to the statistical appearance law of the object region and background information in the clothing image, a bisection method is proposed for the segmentation operation. Since the image is divided into several subimage blocks, bisection image segmentation will be accomplished more efficiently. The experimental results show that the proposed algorithm can quickly and effectively extract effective clothing regions from complex circumstances without any artificial parameters. The proposed clothing image segmentation method will play an important role in computer vision, machine learning applications, pattern recognition and intelligent systems.

A novel synergetic mechanism of hydroxyl radical (•OH) oxidation and an intra-electron-transfer nonradical reaction was found in the catalytic ozonation of ketoprofen (KTP) with the in situ N-doped hollow sphere carbon (NHC). Outperforming the conventional •OH-based catalytic ozonation process, O3/NHC not only realized an enhancement of the pseudo-first-order rate constant of 11 times in comparison with that of O3alone, but was also endowed with a high stability over a wide pH (4–9) and temperature (15–35 °C) range for the degradation of KTP. The high graphitization degree (ID/IG= 0.78–0.88) and low unsaturated oxygen content (0.10–1.38%) of NHC highlighted the dominant role of N-heteroatoms in the O3/NHC system. The specific effects of different N species were confirmed by a relationship study (N property vs catalytic activity) and X-ray photoelectron spectroscopy characterization. The graphitic N forming in the bulk of the graphitic structure served as the “electron-mobility” region to promote KTP degradation with the transfer of electrons from the KTP molecule to O3via a nonradical reaction process. The pyrrolic and pyridinic N located at defects of the graphitic structure acted as the “radical-generation” region to decompose O3into •OH for degrading KTP by a radical oxidation process. This finding provided a brand new insight into engineering N-doped carbonaceous catalysts precisely in the catalytic ozonation process for the efficient treatment of organic-contaminated water.

The initial deposition kinetics of colloidal MnO2on three representative surfaces in aquatic systems (i.e., silica, magnetite, and alumina) in NaNO3solution were investigated in the presence of model constituents, including humic acid (HA), a polysaccharide (alginate), and a protein (bovine serum albumin (BSA), using laboratory quartz crystal microbalance with dissipation monitoring equipment (QCM-D). The results indicated that the deposition behaviors of MnO2colloids on three surfaces were in good agreement with classical Derjaguin–Landau–Verwey–Overbeek (DLVO) theory. Critical deposition concentrations (CDC) were determined to be 15.5 mM NaNO3and 9.0 mM NaNO3when colloidal MnO2was deposited onto silica and magnetite, respectively. Both HA and alginate could largely retard the deposition of MnO2colloids onto three selected surfaces due to steric repulsion, and HA was more effective in decreasing the deposition rate relative to alginate. However, the presence of BSA can provide more attractive deposition site and thus lead to greater deposition behavior of MnO2colloids onto surfaces. The dissipative properties of the deposited layer were also influenced by surface type, electrolyte concentration, and organic matter characteristics. Overall, these results provide insights into the deposition behavior of MnO2colloids on environmental surfaces and have significant implications for predicting the transport potential of common MnO2colloids in natural environments and engineered systems.

In this work, Integrated Mechanical and Thermal Activation (IMTA) process is used to synthesize pure natrium super ion conductor (NaSICON), Na1+xZr2SixP3-xO12 (0 [?] x [?] 3), powder which is then utilized to fabricate NaSICON/polymer composite membranes. The composite membranes are fabricated via tape-casting of a NaSICON slurry, followed by sintering of the green tape to partial densification and then infiltrating the partially sintered tape with polyethylene (PE). The Na-ion conductivities of IMTA-processed NaSICON membranes are characterized and the total conductivity of IMTA-processed membranes without polymer is found to be 3.04 +- 0.1 x 10-4 S/cm, while the sintered bulk density is 3.04 g/cm3. Most importantly, this study has achieved and proved the feasibility and mechanical flexibility of NaSICON/polymer composite membranes.

Lithium ion capacitors (LICs) have the potential to combine the high energy density of lithium ion batteries and the high power density of supercapacitors into one device. In this study, the feasibility of surface functionalization of activated carbon (AC) powder via mechanical activation to serve as the cathode for LICs with non-aqueous electrolytes is investigated. It is found that mechanical activation through high-energy ball milling can impart pseudocapacitance to the AC powder. Although ball milling has reduced the specific surface area, the specific capacitance of the AC powder has increased by 100% because the capacitance per surface area has increased by 3,000%. The capacitance enhancement is mainly attributed to the pseudo-capacitive redox reaction on the C=O sites introduced by mechanical activation.

Background: Identification of immunogenic antigens is an important step for the vaccine improvement. Previous studies indicated that Actinobacillus pleuropneumoniae PalA is homologous to a Haemophilus influenzae protective antigen Hi-PAL (P6) protein. However, PalA protein adversely affects the Apx toxinbased subunit vaccine. The role of PalA in the inactivated vaccine is not known, and the mechanism involved in the PalA-mediated interference has not been investigated. Objectives: The main objective of this study was to investigate the possible impacts of PalA on the protective immunity of A. pleuropneumoniae inactivated vaccine. Methods: Coding sequence of the mature peptide of PalA was amplified from A. pleuropneumoniae SLW01, and inserted into the prokaryotic expression plasmid pGEX-KG, so as to generate the recombinant PalA (rPalA) protein. The immunogenicity of rPalA was verified in rabbits. For the protection assay, mice were assigned into 4 groups, and were immunized with TSB, rPalA, bacterin (Bac) and bacterin + rPalA (BacPal), respectively. Humoral immune response was evaluated before each immunization and before challenge. Two weeks after three immunizations, mice were infected with virulent A. pleuropneumoniae 4074. The clinical signs, survival rates and lung bacteria loads were determined. Then a passive protection assay was performed using pooled sera from the active immunization assay. Results: rPalA was produced in E. coli and was confirmed to be immune-reactive. rPalA is able to elicit a strong humoral immune response in rabbit. Besides, polyclonal antibodies against rPalA is able to recognize the natural PalA in the outer membrane of A. pleuropneumoniae. The positive immunization assay showed that mice immunized with BacPal produced significantly less antibodies against Apx toxins, relative to that of animals immunized with Bac before challenge (P <0.01). After virulent challenge, all mice in the TSB and rPalA groups died within 48 hpi. The survival rates of the Bac and the BacPal groups were 100% and 75%, respectively. The average bacterial loads of the BacPal group was lower than that of the TSB and rPalA groups (P <0.01), but higher than that of the Bac group (P <0.01). The survival rates of mice received pooled anti-sera against TSB, rPalA, BacPal and Bac, were 0%, 0%, 37.5% and 100% after challenge, respectively. In addition, mice in the BacPal group showed moderate to severe lung damage, whereas mice in the Bac group showed relatively normal lung tissues during the histological examination. Conclusion: Our results demonstrate that A. pleuropneumoniae PalA is an immunogenic but not protective antigen, the existence of PalA suppresses the production of protective antibodies, and thus reduces the protective immunity of inactivated vaccine. Therefore, it should be taken into consideration of these immunogenic but not protective proteins during the development of highly effective vaccines in future.

Assembling MnO2nanowires into macroscopic membrane is a promising engineered technology for catalyst separation and enhancement of Fenton-like reaction activity, yet its development is limited by the deficiencies in preparation and property modulation of the MnO2nanowires. In this work, we developed a facile method using C2H5OH and CH3COOK as reductive and vital control reagents to react with KMnO4by hydrothermal reaction at 140 °C for 12 h, to prepare the ultralong α-MnO2nanowires up to tens of micrometers with high purity and aspect ratio. Such strategy not only had the advantages of being mild, easily controlled and environmental pollution-free, but also endowed α-MnO2nanowires with excellent ability as a Fenton catalyst when assembled into free-standing membrane for degrading phenolic compounds (kobs = 0.0738 ∼ 0.1695 min−1) in a continuous flow reaction. The reactive oxygen species (i.e., •OH) from Fenton-like reaction were enriched within this α-MnO2nanowire membrane viananoconfinement effect, which further enhanced the mass transportation of •OH available for phenolic contaminants. MnO2nanowire membrane using our method possessed the high practical potential for water purify due to its easy-preparation and enhanced catalytic performances.

The present study assessed the bioaccumulation potential of per- and polyfluoroalkyl substances (PFAS) in ferns and linked root uptake behaviors to root characteristics and PFAS molecular structure. Tissue and subcellular-level behavioral differences between alternative and legacy PFAS were compared via an electron probe microanalyzer with energy dispersive spectroscopy (EPMA-EDS) and differential centrifugation. Our results show that ferns can accumulate PFAS from water, immobilize them in roots, and store them in harvestable tissue. The PFAS loading in roots was dominated by PFOS; however, a substantial amount of associated PFOS could be rinsed off by methanol. Correlation analyses indicated that root length, surface and project area, surface area per unit length of the root system, and molecular size and hydrophobicity of PFAS were the most significant factors affecting the magnitude of root uptake and upward translocation. EPMA-EDS images together with exposure experiments suggested that long-chain hydrophobic compounds tend to be adsorbed and retained on the root epidermis, while short-chain compounds are absorbed and quickly translocated upward. Our findings demonstrated the feasibility of using ferns in phytostabilization and phytoextraction initiatives of PFAS in the future.

The enhanced piezoelectric and piezo-phototronic performance of ZnO-based thin film devices has been achieved by interface engineering. The piezoelectric performance of ZnO thin film is significantly boosted due to the formation of CuI/ZnO heterojunction, which effectively reduce the unfavorable piezopotential screening effect induced by free electrons in n-type ZnO. Furthermore, taking the advantage of the piezo-phototronic effect, the mechanically generated piezocharges lowers the barrier height which largely facilitates the charge transport across the CuI/ZnO heterojunction/interface and the performance of as-fabricated device were further enhanced by external strains. The photosensing behaviors of the CuI/ZnO photodetector are systematically investigated under different strain and illumination conditions. Under compressive strain, the optimum performance of flexible CuI/ZnO thin film as UV photodetector is attributed to the formation of pn heterojunction, which further modulated through the piezo-phototronic effect and improves the efficiency of charge separation as a result. Our works demonstrate merits of piezoelectric and piezo-phototronic effects for the design of energy harvesting and optoelectronic nanodevices by engineering piezoelectric/semiconductor materials interface.

In this paper, we demonstrate an application of a triboelectric nanogenerator (TENG) as a self-powered communication unit. An elaborately designed TENG is used to translate a series of environmental triggering signals into binary digital signals and drives an electronic–optical device to transmit binary digital data in real-time without an external power supply. The elaborately designed TENG is built in a membrane structure that can effectively drive the electronic–optical device in a bandwidth from 1.30 to 1.65 kHz. Two typical communication modes (amplitude-shift keying and frequency-shift keying) are realized through the resonant response of TENG to different frequencies, and two digital signals, i.e., “1001” and “0110”, are successfully transmitted and received through this system, respectively. Hence, in this study, a simple but efficient method for directly transmitting ambient vibration to the receiver as a digital signal is established using an elaborately designed TENG and an optical communication technique. This type of the communication system, as well as the implementation method presented, exhibits great potential for applications in the smart city, smart home, password authentication, and so on.

In this work, we investigate the improvement in the piezoelectric performance of a ZnO nanowire film by a chemical doping and interfacial modification strategy. The Cl-doped ZnO nanowire films were synthesized by a modified hydrothermal approach and characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, photoluminescence spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, and I–Vcharacterization. The effect of the Cl dopant with different doping concentrations has been demonstrated by an improvement of the piezoelectric output performance due to the induced lattice strain along the ZnO c-axis, which significantly facilitates the piezocharge separation under the applied stress. The experimental results indicate that the existence of lattice strain along the doped ZnO nanowire polar axis resulted from the different ionic sizes between Cl and O. More importantly, by preparing a Cl-doped ZnO nanowire film on a p-type CuO film, our experimental results reveal that the piezoelectric output voltage and current of the Cl-doped ZnO nanowire film can be further enhanced due to the ability of CuO to reduce the electron screening effect. We demonstrate that the utilization of chemical doping and interfacial modification can be considered as a compatible strategy for realizing a high-performance energy-harvesting device.

Flexible self-powered sensing is urgently needed for wearable, portable, sustainable, maintenance-free and long-term applications. Here, we developed a flexible and self-powered GaN membrane-based ultraviolet (UV) photoswitch with high on/off ratio and excellent sensitivity. Even without any power supply, the driving force of UV photogenerated carriers can be well boosted by the combination of both built-in electric field and piezoelectric polarization field. The asymmetric metal–semiconductor–metal structure has been elaborately utilized to enhance the carrier separation and transport for highly sensitive UV photoresponse. Its UV on/off ratio and detection sensitivity reach to 4.67 × 105and 1.78 × 1012cm·Hz0.5W1–, respectively. Due to its excellent mechanical flexibility, the piezoelectric polarization field in GaN membrane can be easily tuned/controlled based on piezo-phototronic effect. Under 1% strain, a stronger and broader depletion region can be obtained to further enhance UV on/off ratio up to 154%. As a result, our research can not only provide a deep understanding of local electric field effects on self-powered optoelectronic detection, but also promote the development of self-powered flexible optoelectronic devices and integrated systems.

In this work, by employing halogen elements (fluorine, chlorine, bromine, and iodine) as dopant we demonstrate a unique strategy to enhance the output performance of ZnO-based flexible piezoelectric nanogenerators. For a halogen-doped ZnO nanowire film, dopants and doping concentration dependent lattice strain along the ZnO c-axis are established and confirmed by the EDS, XRD, and HRTEM analysis. Although lattice strain induced charge separation was theoretically proposed, it has not been experimentally investigated for wurtzite structured ZnO nanomaterials. Tuning the lattice strain from compressive to tensile state along the ZnO c-axis can be achieved by a substitution of halogen dopant from fluorine to other halogen elements due to the ionic size difference between dopants and oxygen. With its focus on a group of nonmetal element induced lattice strain in ZnO-based nanomaterials, this work paves the way for enhancing the performance of wurtzite-type piezoelectric semiconductor nanomaterials via lattice strain strategy which can be employed to construct piezoelectric nanodevices with higher efficiency in a cost-effective manner.

In this study, we have investigated the key factors dictating the cyclic performance of a new type of hybrid sodium-based flow batteries (HNFBs) that can operate at room temperature with high cell voltages (>3 V), multiple electron transfer redox reactions per active ion, and decoupled design of power and energy. HNFBs are composed of a molten Na–Cs alloy anode, flowing aqueous catholyte, and a Na-β″-Al2O3solid electrolyte as the separator. The surface functionalization of graphite felt electrodes for the flowing aqueous catholyte has been studied for its effectiveness in enhancing V2+/V3+, V3+/V4+, and V4+/V5+redox couples. The V4+/V5+redox reaction has been further investigated at different cell operation temperatures for its cyclic stability and how the properties of the solid electrolyte membrane play a role in cycling. These fundamental understandings provide guidelines for improving the cyclic performance and stability of HNFBs with aqueous catholytes. We show that the HNFB with aqueous V-ion catholyte can reach high storage capacity (∼70% of the theoretical capacity) with good Coulombic efficiency (90% ± 1% in 2–30 cycles) and cyclic performance (>99% capacity retention for 30 cycles). It demonstrates, for the first time, the potential of high capacity HNFBs with aqueous catholytes, good capacity retention and long cycling life. This is also the first demonstration that Na-β″-Al2O3solid electrolyte can be used with aqueous electrolyte at near room temperature for more than 30 cycles.

The lithium–sulfur (Li–S) battery is a great alternative to the state-of-the-art lithium ion batteries due to its high energy density. However, low utilization of active materials, the insulating nature of sulfur or lithium sulfide (Li2S), and polysulfide dissolution in organic liquid electrolyte lead to low initial capacity and fast performance degradation. Herein, we propose a facile and viable approach to address these issues. This new approach entails synthesis of Li2S/carbon black (Li2S/CB) cores encapsulated by a nitrogen-doped carbon shell with polyvinylpyrrolidone (PVP) assistance. Combining energy-filtered transmission electron microscopy (EFTEM) elemental mappings, XPS and FTIR measurements, it is confirmed that the as-synthesized material has a structure of a Li2S/CB core with a nitrogen-doped carbon shell (denoted as Li2S/CB@NC). The Li2S/CB@NC cathode yields an exceptionally high initial capacity of 1020 mAh/g based on Li2S mass at 0.1 C with stable Coulombic efficiency of 99.7% over 200 cycles. Also, cycling performance shows the capacity decay per cycle as small as 0.17%. Most importantly, to further understand the materials for battery applications, field emission transmission electron microscopy (FETEM) and elemental mapping tests without exposure to air for Li2S samples in cycled cells are reported. Along with the first ever FETEM and field emission scanning electron microscopy (FESEM) investigations of cycled batteries, Li2S/CB@NC cathode demonstrates the capability of robust core–shell nanostructures for different rates and improved capacity retention, revealing Li2S/CB@NC designed here as an outstanding system for high-performance lithium–sulfur batteries.

A high-resolution dynamic tactile/pressure display is indispensable to the comprehensive perception of force/mechanical stimulations such as electronic skin, biomechanical imaging/analysis, or personalized signatures. Here, we present a dynamic pressure sensor array based on pressure/strain tuned photoluminescence imaging without the need for electricity. Each sensor is a nanopillar that consists of InGaN/GaN multiple quantum wells. Its photoluminescence intensity can be modulated dramatically and linearly by small strain (0–0.15%) owing to the piezo-phototronic effect. The sensor array has a high pixel density of 6350 dpi and exceptional small standard deviation of photoluminescence. High-quality tactile/pressure sensing distribution can be real-time recorded by parallel photoluminescence imaging without any cross-talk. The sensor array can be inexpensively fabricated over large areas by semiconductor product lines. The proposed dynamic all-optical pressure imaging with excellent resolution, high sensitivity, good uniformity, and ultrafast response time offers a suitable way for smart sensing, micro/nano-opto-electromechanical systems.

Reverse electrodialysis (RED) is an emerging membrane-based technology for the production of renewable energy from mixing waters with different salinities. Herein, the impact of the stack configuration on the Ohmic and non-Ohmic resistances as well as the performance of RED were systematically studied by using in situ electrochemical impedance spectroscopy (EIS). Three different parameters (membrane type, number of cell pairs and spacer design) were controlled. The Ohmic and non-Ohmic resistances were evaluated for RED stacks equipped with two types of commercial membranes (Type I and Type II) supplied by Fujifilm Manufacturing Europe B.V: Type I Fuji membranes displayed higher Ohmic and non-Ohmic resistances than Type II membranes, which was mainly attributed to the difference in fixed charge density. The output power of the stack was observed to decrease with the increasing number of cell pairs mainly due to the increase in ionic shortcut currents. With the reduction in spacer thickness from 750 to 200 µm, the permselectivity of membranes in the stack decreased from 0.86 to 0.79 whereas the energy efficiency losses increased from 31% to 49%. Overall, the output of the present study provides a basis for understanding the impact of stack design on internal losses during the scaling-up of RED.

Constructed with parallel or honeycomb channels micrometer to millimeter in diameter, monolithic catalysts and reactors have been utilized in various business sectors ranging from mechanical, automotive, fine chemicals, pharmaceutical, to biotechnology industries. However, the performance of state-of-the-art washcoating monolithic catalysts in industry suffers from some long-standing problems such as mediocre-uniformity, need for high catalyst loading, low materials utilization, random catalytic sites, poor washcoat adhesion, short life-time, degradation tendency, all of which lead to much compromised and less-than desirable catalytic performance. In this work, we significantly mitigated these issues and reduced precious metal and metal oxide usages by 10–40 folds, by directly integrating bare monolith structures with ultra-efficient, thermally stable, and physically and chemically well-defined nanostructure arrays. The well-defined nanostructure array monolithic catalysts represent a new and effective model platform for bridging catalytic nanomaterials science and engineering with the practical industrial catalysis.

A new sepctrofluorimetric method for the determination of doxycycline (DC) was developed based on its enhancement of the fluorescence intensity of europium ion in the presence of sodium dodecyl sulfonate(SDS). The mechanism of fluorescence enhancement was studied. Optimum conditions for the determination of DC were also investigated. The linear range was 0.10- 3.00μg/mL. The detection limit was 1.3ng/mL. There was no interference from the excipients normally used in tablet formulations and the serum compositions. The proposed method was successfully applied to the determination of DC in tablets.

Wandering is a significant indicator in the clinical diagnosis of dementia and other related diseases for elders. Reliable monitoring of long-term continuous movement in indoor setting for detection of wandering movement is challenging because most elders are prone to forget to carry or wear sensors that collect motion information daily due to their declining memory. Wi-Fi as an emerging sensing modality has been widely used to monitor human indoor movement in a non-invasive manner. In order to continuously monitor individuals’ indoor motion and reliably identify wandering movement in a non-invasive manner, in this work, we develop a LSTM-based deep classification method that is able to differentiate the wandering-caused Wi-Fi signal change from the others. Specifically, we first use the off-the-shelf Wi-Fi devices to capture a resident’s indoor motion information, enabling to collect a group of Wi-Fi signal streams, which will be split into variable-size segments. Second, the deep network LSTM is adopted to develop wandering detection method that is able to classify every variable-size segment of Wi-Fi signals into categories according to the well-known wandering spatiotemporal patterns. Last, experimental evaluation conducted on a group of real-world Wi-Fi signal streams shows that our proposed LSTM-based detection method is workable and effective to identify indoor wandering behavior, obtaining an average value of 0.9286, 0.9618, 0.9634 and 0.9619 for accuracy, precision, recall and F-1 score, respectively.

A series of new 34oxo4Hchromen3yl3a,6adihydropyrrolo3,4disoxazole4,6dione have been synthesized by the reaction of Narylmaleimides with nitrile oxide, prepared from αchloro4oxo4Hchromencarbaldehyde oximes in situthrough 1,3dipolar cycloaddition reaction. The structures of all new compounds were confirmed by elemental analysis, ir,1H nmr and mass spectral data.

In this work, Integrated Mechanical and Thermal Activation (IMTA) process is used to synthesize pure natrium super ion conductor (NaSICON), Na1+xZr2SixP3-xO12(0 ≤ x ≤ 3), powder which is then utilized to fabricate NaSICON/polymer composite membranes. The composite membranes are fabricated via tape-casting of a NaSICON slurry, followed by sintering of the green tape to partial densification and then infiltrating the partially sintered tape with polyethylene (PE). The Na-ion conductivities of IMTA-processed NaSICON membranes are characterized and the total conductivity of IMTA-processed membranes without polymer is found to be 3.04 ± 0.1 × 10-4S/cm, while the sintered bulk density is 3.04 g/cm3. Most importantly, this study has achieved and proved the feasibility and mechanical flexibility of NaSICON/polymer composite membranes.

Lithium ion capacitors (LICs) have the potential to combine the high energy density of lithium ion batteries and the high power density of supercapacitors into one device. In this study, the feasibility of surface functionalization of activated carbon (AC) powder via mechanical activation to serve as the cathode for LICs with non-aqueous electrolytes is investigated. It is found that mechanical activation through high-energy ball milling can impart pseudocapacitance to the AC powder. Although ball milling has reduced the specific surface area, the specific capacitance of the AC powder has increased by 100% because the capacitance per surface area has increased by 3,000%. The capacitance enhancement is mainly attributed to the pseudo-capacitive redox reaction on the C=O sites introduced by mechanical activation.

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