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Hydrogen energy has long been recognized as a clean alternative to conventional fossil fuels, which can be applied in a wide range of transportation and power generation applications. The rational design and engineering of high-performance and robust catalysts for hydrogen evolution reaction (HER) shows not a great significance but a challenge for efficient electrochemical water splitting. Herein, a new type of Ni-based Ni-ABDC precursor has been obtained, which leads to the formation of N-doped porous carbon nanomaterials uniformly coated with well-proportioned bimetallic AgNi alloys via a stepwise strategy. To their credit, all samples of AgNi/NC-X are structurally calcined from the pristine AgNi-ABDC-X by tuning the different concentration of AgNO3, which means all of them maintain the vermicelli-like morphology compared with Ni-ABDC. The series of AgNi/NC-X materials can be regarded as effective electrocatalysts for HER both in acidic and alkaline media, but an acid-leaching phenomenon is observed. Among them, the as-prepared AgNi/NC-2 exhibits a low overpotential of 103 mV at the current density of 10 mA cm−2 and decent durability with a high retention rate of 90.9% after 10 h in 1.0 M KOH electrolyte. The compelling HER properties of AgNi/NC-2 can be attributed to the synergistic effect between the hierarchical carbon materials, partial N-doping and abundant AgNi alloys. Meanwhile, this study provides a practicable method for the development of efficient HER electrocatalysts for energy applications, which can be conveniently prepared through the reasonable introduction of active components in the crystalline inorganic-organic precursors.

Herein, copper perrhenate (Cu(ReO4)2) was synthesized using a micro-emulsion method and adhered to graphene (Gr) using an ultrasonic process. Then, the as-prepared Cu(ReO4)2/Gr composite was added into the synthetic oil as a lubricant additive with the help of ionic liquid to achieve enhanced dispersion stability within the base oil. The tribological performances of the Cu(ReO4)2/Gr additive were investigated using four-ball tests and the ball-on-disk reciprocating configuration under various temperatures. The potential lubrication mechanisms of the Cu(ReO4)2/Gr additive were performed using a series of characterization methods including XRD, Raman, SEM-EDS, TEM, DSC/TG, and XPS. The results of four-ball tests at room temperature indicated that the Cu(ReO4)2/Gr additive could substantially improve the tribological performances of the base oil. The smallest coefficient of friction (COF) and wear scar diameter (WSD) values were 0.068 and 495 μm, respectively, when 0.05 wt% of Cu(ReO4)2/Gr was added. Additionally, the graphene accelerated friction-induced heat transfer, which led to decreased friction and wear. The results of reciprocating friction experiments at elevated temperatures revealed that the Cu(ReO4)2/Gr additive had excellent friction-reduction properties when the temperature was high. This could be attributed to the generation of a protective layer containing tribo-oxides from the alloy, some residual carbides and copper perrhenate induced by friction heat and stress. This protective layer was uniformly and stably covered on the worn surface, which could effectively alleviate direct contact between the rubbing pair.

Estimating passengers’ door-to-door travel time, for journeys that combine walking and public transit, can be complex for large networks with many available path alternatives. Additional complications arise in tap-on only transit systems, where passengers alightings are not recorded. For one such system, the Chicago Transit Authority, this study compares three methods for estimating door-to-door travel time: assuming optimal path choice given scheduled service, as represented in the General Transit Feed Specification (GTFS); assuming optimal path choice given actually operated bus service, as recorded by automatic vehicle location systems; and using inferred path choices based on automated fare collection smartcard records, as processed with an origin-destination-interchange (ODX) inference algorithm. As expected, ODX-derived travel times are found to be longer than those derived from GTFS, indicating that purely schedule-based travel times underestimate the travel times that are actually available and experienced, which can be attributed primarily to suboptimal passenger route choice. These discrepancies additionally manifest in significant spatial variations, raising concerns about potential biases in travel time estimates that do not account for reliability. The findings bring about a more comprehensive understanding of the interactions between transit reliability and passenger behavior in transportation research. Furthermore, these discrepancies suggest areas of future research into the implications of systematic and behavioral assumptions implied by using conventional schedule-based travel time estimates.

Disposal of the pollutants arising from farming cattle and other livestock threatens the environment and public safety in diverse ways. Herein, we report on the synthesis of engineered biochars using cow dung as raw material, and investigating these biochars as antibacterial agents for water decontamination. By coating the biochars with N-halamine polymer and loading them with active chlorine (i.e., Cl+), we were able to regulate them on demand by tuning the polymer coating and bleaching conditions. The obtained N-halamine-modified biochars were found to be extremely potent against Escherichia coli and Staphylococcus aureus. We also investigated the possibility of using these N-halamine-modified biochars for bacterial decontamination in real-world applications. Our findings indicated that a homemade filter column packed with N-halamine-modified biochars removed pathogenic bacteria from mining sewage, dairy sewage, domestic sewage, and artificial seawater. This proposed strategy could indicate a new way for utilizing livestock pollutants to create on-demand decontaminants.

Herein, Polyester woven fabrics as the matrices for the experimental group, while cotton knitted fabrics, cotton woven fabrics, and Polyethylene terephthalate (PET) mesh cloth used as the matrices for the control groups, at 40 °e, using 3,4-ethoxylene dioxy thiophene (EDOT)as the polymer monomer, FeCl3as the oxidant, and poly(sodium-p-styrenesulfonate) (PSS) as the dopant, are separately coated with PEDOT:PSS polymer to prepare flexible conductive composite fabrics. The influences of the fabric pattern, oxidant concentration, and monomer concentration on the electrical performance of composite fabrics are optimized. The maximal electrical conductivity of PET-based composite fabrics (218 S/m) occurs when monomer concentration is 0.035 mol/L, the molar ratio of oxidant to monomer is 2.5, and the dopant concentration is 2.5 g/L. Moreover, bacteriostasis rate of this composite fabric reaches 71.8%. Furthermore, by electrocardiogram (ECG) simulated human body unit test as well as human body ECG test, the optimal PET-based composite fabric electrode both has a lower impedance which helps form the stabilized ECG signal. The resulting fabric electrodes retain the soft and breathable advantages from fabrics and reduce the discomfort for a long-term use of conventional electrographic gel, thereby validating the empirical evidence for mobile, portable, wearable ECG electrodes.

Narrow-band-gap III-V semiconductor nanowires (NWs) with a suitable band structure and strong light-trapping ability are ideal for high-efficiency low-cost solar water-splitting systems. However, due to their nanoscale dimension, they suffer more severe corrosion by the electrolyte solution than the thin-film counterparts. Thus, short-term durability is the major obstacle for using these NWs for practical water-splitting applications. Here, we demonstrated for the first time that a thin layer (∼7 nm thick) of compact TiO2 deposited by atomic layer deposition can provide robust protection to III-V NWs. The protected GaAs NWs maintain 91.4% of its photoluminescence intensity after 14 months of storage in ambient atmosphere, which suggests the TiO2 layer is pinhole-free. Working as a photocathode for water splitting, they exhibited a 45% larger photocurrent density compared with unprotected counterparts and a high Faraday efficiency of 91% and can also maintain a record-long highly stable performance among narrow-band-gap III-V NW photoelectrodes; after 67 h photoelectrochemical stability test reaction in a strong acid electrolyte solution (pH = 1), they show no apparent indication of corrosion, which is in stark contrast to the unprotected NWs that fully failed after 35 h. These findings provide an effective way to enhance both stability and performance of III-V NW-based photoelectrodes, which are highly important for practical applications in solar-energy-based water-splitting systems.

One of the difficulties in atherosclerosis treatment is that the ablation of inflammatory macrophages, repair of vascular endothelial injury, and anti-tissue proliferation should be considered. However, there are few studies that can solve the abovementioned problems simultaneously. Herein, we present a kind of near-infrared (NIR) light-driven multifunctional mesoporous/macroporous tubular micromotor which can rapidly target the damaged blood vessels and release different drugs. Their motion effect can promote themselves to penetrate into the plaque site, and the generated heat effect caused by NIR irradiation can realize the photothermal ablation of inflammatory macrophages. Furthermore, these micromotors can rapidly release the vascular endothelial growth factor for endothelialization and slowly release paclitaxel for antiproliferation to achieve synergistic treatment of atherosclerosis. In vivo results demonstrated that the micromotors can achieve a good therapeutic effect for atherosclerosis. This kind of micro/nanomotor technology with a complex porous structure for drug loading will bring a more potential treatment platform for the disease.

A porous supramolecular framework has been for the first time revealed to undergo interpenetration in crystal and non-interpenetration in solution. A new supramolecular organic framework Bu-SOF has been constructed from the co-assembly of a tetracationic tetrahedral monomer and cucurbit[8]uril (CB[8]) in water through the encapsulation of two anti-parallel n-butyl chains by CB[8]. X-ray diffraction analysis reveals that Bu-SOF forms 3-fold interpenetrated networks in crystals grown by evaporation of its solution in water. 1H NMR, dynamic light scattering and isothermal titration calorimetric experiments confirm that Bu-SOF is also formed in water. Solid samples, prepared by lyophilizing the aqueous solution of Bu-SOF, can adsorb nanoscaled organic dyes, supporting the porosity of the framework and thus non-interpenetration in solution. The avoidance of interpenetration of Bu-SOF in solution has been attributed to the filling of water inside the porous framework as well as the electrostatic repulsion of the appended bipyridinium units of the tetrahedral building block.

Destruction of tumor metabolism symbiosis is an attractive cancer treatment method which targets tumor cells with little harm to normal cells. Yet, a single intervention strategy and poor penetration of the drug in tumor tissue result in limited effect. Herein, we propose a zero-waste zwitterion-based hydrogen sulfide (H 2 S)-driven nanomotor based on the basic principle of reaction in human body. When loaded with monocarboxylic acid transporter inhibitor α-cyano-4-hydroxycinnamic acid (α-CHCA), the nanomotor can move in tumor microenvironment and induce multiple acidosis of tumor cells and inhibit tumor growth through the synergistic effect of motion effect, driving force H 2 S and α-CHCA. Given the good biosafety of the substrate and driving gas of this kind of nanomotor, as well as the limited variety of nanomotors currently available to move in the tumor microenvironment, this kind of nanomotor may provide a competitive candidate for the active drug delivery system of cancer treatment.

Rapid screening monofluoroacetic acid (FAcOH) is responsible for preventing chemical poisoning and food safety events. Whereas surface enhanced Raman scattering (SERS) spectra is an effective tool for detecting forbidden chemicals, it is difficult to directly detect FAcOH due to its small Raman scattering cross section as well as weak adsorption on SERS substrates. In this work, the metal phenolic supramolecular networks (MPNs, i.e., the tannic acid and Fe3+ complex) were fabricated on the commercial nanoanodic aluminum oxide film (NAAO) for assisting in situ chemical deposition highly uniform Ag nanostructure over large areas (the NAAO@AgNS). The low cost and simple fabrication process made the NAAO@AgNS a single-use consumable. For FAcOH detection, a specific derivative reaction between FAcOH and thiosalicylic acid (TSA) was introduced. By taking TSA as the Raman probe, its SERS signal attenuated constantly with the increasing amount of FAcOH. For improving quantitative accuracy, thiocyanate (SCN-) was introduced on the NAAO@AgNS as an internal standard; thus, the characteristic peak intensity ratios associated with TSA and SCN- (I1035/I2125) were fitted to the concentration of FAcOH. It was demonstrated that the SERS assay achieved good sensitivity and selection toward FAcOH with the limit of quantitation (LOD) as low as 50 nmol L-1. The NAAO@AgNS featured with highly sensitive, uniform, and consistent SERS performances could easily extend to wide SERS applications.

The rational design and facile synthesis of transition metal-based catalysts supported by carbon nanomaterials with high activity, selectivity and stability remain a great challenge. Recently, the low-cost, stable and high-performance electrocatalysts for efficient oxygen evolution reaction (OER) derived from porous metal-organic framework (MOF) precursors have attracted numerous attention. Herein, a new type of CoMo carbide/nitride embedded in the flower-like carbon materials (CoMo-MI-T, MI = 2-Methylimidazole, T = 400, 500, 600, 700 °C) has been synthesized by a simple pyrolysis, in which bimetallic CoMo-MI precursors can be conveniently converted from crystalline cobalt-based MOFs of Co-MI by solvothermal reaction. The pyrolyzed CoMo-MI-T series exhibits a hierarchically porous nanostructure, high Co3Mo3C/N content, suitable N-doping, graphitic carbon layers as well as well-preserved flower-shaped morphology, which shows an excellent OER performance. Among them, the most optimal CoMo-MI-600 owns the small overpotential of 316 mV at 10 mA cm−2 and Tafel slope of 89.9 mV dec−1 in 1.0 M KOH solution. Meanwhile, the rotating ring-disk electrode technique is examined to verify near 4-electron transfer process for CoMo-MI-600 together with a high Faradaic efficiency of 98.7%. The well-performed CoMo-MI-600 electrocatalyst may be stemmed from the best balance of the synergistic effect of abundant multi-component, suitable electrical conductivity and large porosity. The current work will provide a new route to prepare MOF-derived bimetallic active sites in porous carbon nanomaterials with satisfactory activity and robust stability in the relevant energy applications.

As a signaling molecule, hydrogen sulfide (H2S) plays an indispensable role in the modulation of ripening and senescence in fruits and vegetables. To explore the role of H2S in regulating metabolism of postharvest tomato, ripening-related physiological parameters, activities of antioxidant enzymes and gene expression were analyzed in H2S-fumigated tomato fruits. These results show that H2S significantly delayed the color transition and softening of tomato fruit, and maintained higher level of flavonoids and lower level of anthocyanin during storage. Besides, H2S could maintain higher level of nutritional-related metabolites, such as reducing sugar, ascorbic acid during postharvest storage. Moreover, H2S decreased the rate of O2− production, inhibited the production of H2O2 and malondialdehyde (MDA), enhanced the activities of antioxidant enzymes including ascorbate peroxidase (APX), superoxide dismutase (SOD), catalase (CAT) and guaiacol peroxidase (POD) in tomato fruits, while reduced the activities of phenylalanine ammonia lyase (PAL), polyphenol oxidase (PPO) and lipoxygenase (LOX). Besides, the expression of the antioxidant-encoding genes SlCAT2, SlPOD12 was generally upregulated with H2S fumigation. Principal component analysis (PCA) suggests that H2S induced significant discrepancy mainly to the differences in firmness, anthocyanin, flavonoid and the activity of guaiacol peroxidase (POD), and the correlation analysis further shows that H2S affected pigment metabolism and nutritional quality. In conclusion, H2S could maintain better appearance and nutritional quality, and prolong the storage period of postharvest tomato fruits through activating the antioxidative system.

The determination of ecological environment damage baseline is the basis of natural resources damage assessment. In complex damage assessment, the importance of baseline is often underestimated or ignored. The existing baseline determination methods have the problems of insufficient accuracy and poor availability in practical application, which affect the damage assessment work to a certain extent. Based on the definition of baseline and the shortcomings of existing baseline determination methods, this paper puts forward the determination principle of the original site point (OSP) method. The baseline calculation area can be directly determined according to the site conditions in the sludge storage site with clear pollution distribution, and the OSP method has certain advantages in the rapidity of determining the baseline. The baseline calculation area should be determined according to the preliminary and detailed sampling data for the waste oil sludge storage site with unclear pollution distribution. The calculation results of the two sites show that the baseline determined by the OSP method and the reference point (RP) method are similar, and the results of the environmental standard (ES) method are much higher than those of the two methods. The order of accuracy of baseline determination methods is the historical data (HD) method > the OSP method > the RP method > the model calculation (MC) method > the ES method. Through two application cases, this paper discusses the applicability of the OSP method, and finally establishes the determination steps of the method. The OSP method is proved to be an effective method to determine the baseline, and the fast and accurate baseline determination method is more helpful to the damage assessment. This article is protected by copyright. All rights reserved.

Penicillium digitatum is the primary pathogen that causes serious yield losses worldwide. In our previous study, CsWRKY transcription factors (TFs) and some genes associated with immunity were identified in citrus fruits after P. digitatum infection, but little information is available in the literature on the mechanisms of TFs in citrus disease resistance. In this study, the possible mechanisms of CsWRKY65 participating in the establishment of disease resistance were investigated. Results show that CsWRKY65 was a transcriptional activator in the nucleus. The dual-luciferase transient assays and electrophoretic mobility shift assays showed that CsWRKY65 bound with CsRbohB, CsRbohD, CsCDPK33, and CsPR10 promoters to activate gene transcription. Besides, the transient overexpression of CsWRKY65 induced reactive oxygen species accumulation and increased PR gene expression in Nicotiana benthamiana leaves. The transient overexpression of CsWRKY65 in the citrus peel enhanced the disease resistance against P. digitatum. In conclusion, CsWRKY65 is likely to be involved in regulating the disease resistance to P. digitatum of citrus fruits by directly activating the expressions of CsRbohB, CsRbohD, CsCDPK33, and CsPR10. This study provides new information for the mechanism of citrus WRKY TFs participating in the establishment of disease resistance.

Polymer dielectrics with super dielectric constant (e'), low loss as well as high thermal conductivity (TC) are gaining tremendous momentum owing to the ever-increasing demands on microelectronic devices. Introduction core–shell fillers into polymers has been demonstrated as a promising strategy for high-e' but low loss. Herein, nickel (Ni) particles were encapsulated by an insulating layer of NiO with various thicknesses via controlling calcination times at 550 °C under air, and the as-prepared core–shell Ni@NiO was incorporated into poly(vinyli-dene fluoride) (PVDF). The results verify the formation of a NiO shell outside of the Ni, and manifest that the PVDF with Ni@NiO particles exhibit a high e', a signally suppressive loss and conductivity, as well as a high-TC compared with raw Ni. The reason can be ascribed to multiple effects of NiO interlayer including the enhancement of interface compatibility and interface polarizations and the blocking of leakage current. Furthermore, the thickness of NiO shell exerts different influences on long-range and short-range charge migration, and it should be rationally tuned to optimize the dielectric properties and TC. This study provides an effective idea to regulate and control the dielectric properties and TC of polymer composites.

In the current study, by using the mixed-ligand synthesis approach, two new Cu(II)-containing coordination polymers (CPs), namely, {[Cu3(μ4-cpboda)2(μ1,1-OH2)2(2,2-bipy)2]·1.5DMF·2H2O}n (1) and {[C...

We have synthesized a flexible polyurethane foam composite filled with expanded vermiculite powder and covered by concave-convex structural panel in order to improve the compression and cushioning property of PU foam. Concave-convex structural panel is that fabric cubes consisting of three layers of warp-knitted spacer fabrics arranged isometric apart between two layers of low-melting-point PET fabrics and then thermally processed at 180 °C. Effects of particle size and content of expanded vermiculite powders as well as the presence of concave-convex structural panel are examined in terms of foam structure and mechanical properties of composite PU foams. Expanded vermiculite addition decreases the energy required by pore nucleation, and the higher content of expand vermiculite results in pore diameter of foam and greater compression property. Filling of 2% vermiculites makes the compression property improved by 239% at 40% strain. Moreover, the smaller size of expanded vermiculite generates smaller and denser foam pore diameter and thus strengthened compression property. Foam composite with 800-mesh expanded vermiculites show the excellent compression property that 307% higher than neat PU foam at 40% strain. Concave-convex structural panel enhanced compression properties by 852% when fabric cubes arranged 1 cm apart and cushion efficiency by 29% compared to pure PU foam when fabric cubes arranged 4 cm apart. The resultant flexible polyurethane foam can absorb 97% energy at 12 J impact level. This composite can serve as the protective materials in kindergarten and old people's home.

The content of heavy pitch in tar generated from coal pyrolysis is high. To improve the quality of tar, catalysts are applied for adjusting the reaction of volatiles during coal pyrolysis. However, catalysts are easy to deactivate due to coke deposition. In this study, coke amount on activated carbon catalysts during catalytic upgrading of coal pyrolysis volatiles was investigated in the downer-bed reactor. The process of coke formation was studied at different feed time (30, 60 and 100 min) of coal. Results show that a great amount of coke is generated on the activated carbons. With the increase of feed time, the amount of coke on activated carbon increases, while the rate of coke formation decreases, thus decreasing the coke yield based on dry coal. The specific surface area and catalytic cracking activity of the activated carbon decrease with the increase of coke amount. Hence, the yields of tar and pitch increase with the increase of feed time. The relative content of oxygen-containing compounds in the tar increases with the increase of feed time, which indicates that the cleavage of weak chemical bond C–O is suppressed. That may result in a decrease in the rate of coke formation.

The char powder entrained in gaseous tar influences the reaction of gaseous tar that exists in the transportation pipeline or dust removal equipment, which further affects the distribution and composition of pyrolysis products. This study investigated the effect of char powder on the reaction of gaseous tar during Naomaohu long-flame coal pyrolysis from 400to 500°C in atwo-stage fluidized bed reactor. Results indicated that in addition to its thermal cracking and polycondensation reactions, catalytic cracking reaction of gaseous tar also occurred when char powder was added, resulting in the decrease of tar yieldand pitch content, and the increase of pyrolysis gases and coke yield at different reaction temperatures. The thermal cracking and polycondensation reactionsofgaseous tar intensified with increasing reaction temperature, which stabilized the gaseous tar and made it difficult to be catalyzed by char powder. Therefore, with the increase of reaction temperature, the influences of char powder ontar yield, tar pitch content and pyrolysis gases yield were reduced. The polycondensation reaction of free radicals from catalytic cracking of gaseous tar was prone to occur with increasing reaction temperature, which enhanced the effect of char powder on coke yield. Also, the catalytic cracking action of char powder reduced the content of heterocyclic compounds in tar at different reaction temperatures, and the reaction between gaseous tar and water was promoted by char powder, resulting in the decrease of aliphatics and aromatics contents in tar, and the increase of phenols and oxygenated compounds contents in tar at different reaction temperatures.

Center pivot irrigation systems are used to enhance crop production in many countries around the world. Establishing the location and extent of such fields provides information that assists in describing a range of agricultural metrics, including crop identification, yield forecasts, monitoring of irrigation requirements and crop water use, as well as supporting national and regional auditing, licensing and compliance efforts. However, detailed information on the number, extent and changing dynamics of agricultural fields is often lacking in many countries: nowhere more so than in developing regions. To address this lack, we performed a national scale accounting of center pivot fields in Saudi Arabia, using a three year multi-temporal analysis of Landsat-8 satellite data. A geographic object-based image analysis approach was developed based on five 50 × 50 km sub-areas extracted from Landsat data for the year 2015, and applied to delineate individual center pivot fields at a national scale for 2013, 2014 and 2015. The extent of fields was determined via a map of the annual maximum Normalized Difference Vegetation Index (NDVI), while a 15 m spatial resolution map of annual panchromatic band minimums was used to produce an edge detection layer to delineate individual adjoining fields. Amongst a range of classification parameters that were included in the object-based mapping approach, shape information, such as the center pivot field length, length:width ratio, and elliptic fit, were identified as critical parameters. Applying the rule-set that was developed from the five 50 × 50 km sub-regions to the national scale resulted in the identification of 36,052 (11,103 km2), 38,114 (11,902 km2), and 37,254 (11,555 km2) individual fields in 2013, 2014, and 2015, respectively. Approximately 94% of these fields were correctly detected, while their individually measured area was mapped with >95% combined accuracy for fields >0.225 km2 when evaluated against manually delineated fields. Smaller center pivot fields, and specifically those adjoining neighbouring fields, had lower area mapping accuracies (>91% in 75% of cases). The object-based approach allowed a national scale and multi-temporal assessment of center pivot field delineation and mapping, affording new insights into agricultural practice and providing a methodological basis for examining the impact of water management and related policy initiatives, amongst many other potential applications. Apart from filling a clear knowledge gap in Saudi Arabia, the approach has the potential to be expanded elsewhere: particularly to similar locations within the Middle East and North Africa.

This article reports the glass transition temperatures of poly-( p-phenylenediamine-alt-2,6-diformyl multiphenyl) predicted by both the group contribution method and the molecular dynamics simulations. The related modeling method and the degree of polymerization, density, specific volume, radius of volume, radius of rotation, and non-bonding energy terms with temperature are analyzed in depth. The bulk modulus, shear modulus, compressibility, Young’s modulus, and Poisson’s ratio of poly-( p-phenylenediamine-alt-2,6-diformyl multiphenyl) at room temperature are simulated by molecular dynamics. The results show that the simulated glass transition temperatures of poly-( p-phenylenediamine-alt-2,6-diformyl multiphenyl) are greater than 480 K, which indicates that poly-( p-phenylenediamine-alt-2,6-diformyl multiphenyl) can be expected to be used as a high-temperature-resistant material. As the number of rigid benzene rings on the molecular side chain increases, the glass transition temperature decreases, with an average decrease of 10 K for each additional benzene ring. The free volume theory can explain the glass transitions of poly-( p-phenylenediamine-alt-2,6-diformyl multiphenyl). The modulus and density of poly-( p-phenylenediamine-alt-2,6-diformyl multiphenyl) change accordingly with an increase of rigid benzene rings on the side chain, probably due to the fact that the flexibility of the polymers changes accordingly as the number of benzene rings on the side chain increases.

Sialic acid (SA) plays important roles in various biological and pathological processes. Methods for monitoring and detection of SA are of great significance in terms of fundamental research, cancer diagnostics, and therapeutics, which are still limited until now. Here, a phenylboronic acid (PBA)-functionalized pyrene derivative, 4-(4-(pyren-1-yl)butyramido)phenylboronic acid (Py-PBA), was synthesized and used as a building block for self-assembling into hydrophilic nanorods. The Py-PBA nanorods (Py-PBA NRs) featured highly specific and efficient imaging of SA on living cells with the advantages of excellent fluorescence stability, good biocompatibility, and unique two-photon fluorescence properties. Meanwhile, the assembled Py-PBA NRs could efficiently generate 1O2 under two-photon irradiation, making it an excellent candidate for photodynamic therapy. This nanoplatform realized in situ recognition and two-photon imaging of SA on the cell surface as well as effective cancer cell therapy, providing a potential method for simple and selective analysis of SA in living cells and a new prospect for image-guided therapy.

The poor interfacial adhesion of aramid fiber and matrix limits the application of the final composites. In this study, a series of the sulfone-functionalized poly( p-phenylene terephthalamide) (SPPTA) copolymers were satisfactorily synthesized and the effects of polymerization conditions (contents of the additional monomer and the cosolvent LiCl, molar concentration and ratio of the monomer, reaction temperature and time) on the molecular weight of the copolymer were discussed. The introduction of the sulfone group in aromatic polyamides not only increased the polarity of poly( p-phenylene terephthalamide) (PPTA) but destroyed the regular arrangement of the molecular chains, which greatly improved the surface free energy and the solubility of the polymers in organic solvents. The polymer maintained excellent thermal and interfacial properties. Compared with the PPTA fiber/epoxy composites, the interfacial shear strength (IFSS) of SPPTA fiber-reinforced epoxy composites reached 43.5 MPa, with a significantly enhancement of 20.8%, implying that the study provided an effective method to achieve highly interfacial adhesion of aramid fiber-reinforced composites.

Selective hydrogenation of CO2 to methanol is a "two birds, one stone" technology to mitigate the greenhouse effect and solve the energy demand-supply deficit. Cu-based catalysts can effectively catalyze this reaction but suffer from low catalytic stability caused by the sintering of Cu species. Here, we report a series of zeolite-fixed catalysts Cu/ZnOx(Y)@Na-ZSM-5 (Y is the mass ratios of Cu/Zn in the catalysts) with core-shell structures to overcome this issue and strengthen the transformation. Fascinatingly, in this work, we first employed bimetallic metal-organic framework, CuZn-HKUST-1, nanoparticles (NPs) as a sacrificial agent to introduce ultrasmall Cu/ZnOx NPs (∼2 nm) into the crystalline particles of the Na-ZSM-5 zeolite via a hydrothermal synthesis method. The catalytic results showed that the optimized zeolite-encapsulated Cu/ZnOx(1.38)@Na-ZSM-5 catalyst exhibited the space time yield of methanol (STYMeOH) of 44.88 gMeOH·gCu-1·h-1, much more efficient than the supported Cu/ZnOx/Na-ZSM-5 catalyst (13.32 gMeOH·gCu-1·h-1) and industrial Cu/ZnO/Al2O3 catalyst (8.46 gMeOH·gCu-1·h-1) under identical conditions. Multiple studies demonstrated that the confinement in the zeolite formwork affords an intimate surrounding for the active phase to create synergies and avoid the separation of Cu-ZnOx interfaces, which results in an improved performance. More importantly, in the long-term test, the Cu/ZnOx(1.38)@Na-ZSM-5 catalyst exhibited constant STYMeOH with superior durability benefitted from its fixed structure. The current findings demonstrate the importance of confinement effects in designing highly efficient and stable methanol synthesis catalysts.

The first CuI-catalyzed decarboxylative thiolation of terminal alkyne-substituted cyclic carbonates/carbamates to access allenes has been developed. A wide range of hydroxymethyl- and aminomethyl-containing allenyl thioethers were smoothly obtained in good to excellent yields under mild conditions. The copper-allenylidene intermediate among the process is crucial to the decarboxylative thiolation reaction. This method opens up a new channel to access allenyl thioether compounds.

Maize (Zea mays L.) germplasm in China Summer maize ecological region (CSM) or central corn-belt of China is diverse but has not been systematically characterized at molecular level. In this study, genetic variation, genome diversity, linkage disequilibrium patterns, population structure, and characteristics of different heterotic groups were studied using 525,141 SNPs obtained by Genotyping-By-Sequencing (GBS) for 490 inbred lines collected from researchers at CSM region. The SNP density is lower near centromere, but higher near telomere region of maize chromosome, the degree of linkage disequilibrium (r2) vary at different chromosome regions. Majority of the inbred lines (66.05%) show pairwise relative kinship near zero, indicating a large genetic diversity in the CSM breeding germplasm. Using 4849 tagSNPs derived from 3618 haplotype blocks, the 490 inbred lines were delineated into 3 supergroups, 6 groups, and 10 subgroups using ADMIXTURE software. A procedure of assigning inbred lines into heterotic groups using genomic data and tag-SNPs was developed and validated. Genome differentiation among different subgroups measured by Fst, and the genetic diversity within each subgroup measured by GD are both large. The share of heterotic groups that have significant North American germplasm contribution: P, SS, IDT, and X, accounts about 54% of the CSM breeding germplasm collection and has increased significantly in the last two decades. Two predominant types of heterotic pattern in CSM region are: M-Reid group × TSPT group, and X subgroup × Local subgroups.

A BiFeO3/TiO2 p-n heterojunction photocatalyst with ferroelectric synergistic effect under visible-light irradiation was developed through facile hydrolysis and precipitation by forming nanospheres of TiO2 on BiFeO3 nanocube to improve the photocatalytic efficiency. Analyses of the microstructure, optical properties, and photoelectrochemical performance indicate the formation of a core–shell heterostructure of BiFeO3/TiO2 with excellent energy band matching. The BiFeO3/TiO2 p-n heterojunction has enlarged specific surface area, higher sensitivity to visible-light, and improved separation and transfer efficiency of photoelectron-hole pairs than single TiO2 and BiFeO3. Moreover, the composite exhibits superior photocatalytic degradation performance for methylene blue (MB) and common antibiotic tetracycline (TC) under UV and visible-light irradiation. The MB degradation rate within 180 min reaches 78.4% and 90.4% under UV and visible-light irradiation, respectively. Furthermore, the enhanced photocatalytic mechanism of BiFeO3/TiO2 is explored by photoluminescence (PL), electrochemical impedance spectroscopy (EIS), transient photocurrent analysis, radical quenching, and band structure characterization.

Reasonable design of the porous metal-organic frameworks (MOFs) to convert a burgeoning carbon-based catalysts with high oxygen reduction reaction (ORR) activity are still challenging in energy conversion, storage and transport. Herein, Fe7C3-doped in-situ grown carbon nanotubes and N-doped hollow carbon (Fex-CNT@NHC) are prepared by using a simple and robust preparation method, which is used cubic ZIF-8-derived zinc oxide cubes as a template for secondary MOFs re-growth followed by the final carbonization. In the 0.1 M KOH, the as-pyrolyzed Fe0.1-CNT@NHC electrocatalyst displays the value of half-wave potential is 0.92 V and the value of diffusion-limited current density is 6.08 mA cm−2, respectively, which are close to the corresponding electrochemical values of the standard commercial Pt/C (0.89 V and 5.89 mA cm−2). Meanwhile, the material has passed relevant tests on its long-term stability and methanol tolerance in alkaline media, showing that it has excellent ORR activity and efficient stability under electrocatalysis. Furthermore, the Fe0.1-CNT@NHC materials catalyze a Zn-air battery that delivers a performed peak power density of 105.9 mW cm−2. The impressive catalytic activity of Fe0.1-CNT@NHC stems from the effective synergy between efficient Fe and N co-doping, large specific surface area, and high electrical conductivity. This preparation route for carbon nanomaterials will provide a new synthetic strategy to synthesize high-performance non-noble metal carbon-based ORR catalysts for practical energy-related applications.

Nan-Fu Chiu,1,2 Ming-Jung Tai,1 Devi Taufiq Nurrohman,1,3 Ting-Li Lin,1 Ying-Hao Wang,1 Chen-Yu Chen4,5 1Laboratory of Nano-Photonics and Biosensors, Institute of Electro-Optical Engineering, National Taiwan Normal University, Taipei City, Taiwan; 2Department of Life Science, National Taiwan Normal University, Taipei City, Taiwan; 3Department of Electronics Engineering, State Polytechnic of Cilacap, Cilacap, Indonesia; 4Department of Obstetrics and Gynecology, Mackay Memorial Hospital, Taipei City, Taiwan; 5Department of Medicine, Mackay Medical College, Taipei City, TaiwanCorrespondence: Nan-Fu ChiuLaboratory of Nano-Photonics and Biosensors, Institute of Electro-Optical Engineering, National Taiwan Normal University, No. 88, Sec. 4, Ting-Chou Road, Taipei City, 11677, TaiwanTel +886-2-77496722Fax +886-2-86631954Email nfchiu@ntnu.edu.twChen-Yu ChenDepartment of Obstetrics and Gynecology, Mackay Memorial Hospital, No. 92, Sec. 2, Zhongshan N. Road, Taipei City, 10449, TaiwanTel +886-2-25433535Fax +886-2-25433642Email f122481@mmh.org.twBackground: Due to educational, social and economic reasons, more and more women are delaying childbirth. However, advanced maternal age is associated with several adverse pregnancy outcomes, and in particular a high risk of Down’s syndrome (DS). Hence, it is increasingly important to be able to detect fetal Down’s syndrome (FDS).Methods: We developed an effective, highly sensitive, surface plasmon resonance (SPR) biosensor with biochemically amplified responses using carboxyl-molybdenum disulfide (MoS2) film. The use of carboxylic acid as a surface modifier of MoS2 promoted dispersion and formed specific three-dimensional coordination sites. The carboxylic acid immobilized unmodified antibodies in a way that enhanced the bioaffinity of MoS2 and preserved biorecognition properties of the SPR sensor surface. Complete antigen pregnancy-associated plasma protein-A2 (PAPP-A2) conjugated with the carboxyl-MoS2-modified gold chip to amplify the signal and improve detection sensitivity. This heterostructure interface had a high work function, and thus improved the efficiency of the electric field energy of the surface plasmon. These results provide evidence that the interface electric field improved performance of the SPR biosensor.Results: The carboxyl-MoS2-based SPR biosensor was used successfully to evaluate PAPP-A2 level for fetal Down’s syndrome screening in maternal serum samples. The detection limit was 0.05 pg/mL, and the linear working range was 0.1 to 1100 pg/mL. The women with an SPR angle > 46.57 m° were more closely associated with fetal Down’s syndrome. Once optimized for serum Down’s syndrome screening, an average recovery of 95.2% and relative standard deviation of 8.5% were obtained. Our findings suggest that carboxyl-MoS2-based SPR technology may have advantages over conventional ELISA in certain situations.Conclusion: Carboxyl-MoS2-based SPR biosensors can be used as a new diagnostic technology to respond to the increasing need for fetal Down’s syndrome screening in maternal serum samples. Our results demonstrated that the carboxyl-MoS2-based SPR biosensor was capable of determining PAPP-A2 levels with acceptable accuracy and recovery. We hope that this technology will be investigated in diverse clinical trials and in real case applications for screening and early diagnosis in the future.Keywords: carboxyl-functionalized molybdenum disulfide, carboxyl-MoS2, surface plasmon resonance, SPR, pregnancy-associated plasma protein A2, PAPP-A2, Down’s syndrome, DS, fetal Down’s syndrome, FDS

Li metal possesses a high theoretical specific capacity, high electronic conductivity, and a low electrochemical potential, making it a promising anode material for building next-generation rechargeable metal batteries. In case conventional liquid electrolytes were used, and the anode using Li metal has been hindered by unstable(electro)chemistry at Li/electrolyte interface and the accompanied dendrite issue. Specifically, for the Li-Se batteries, the dissolution and shuttle of polyselenide intermediates lead to the deposition of poorly-conductive species on the anode, which further aggravates the chemical environment at the anode. In this work, we proposed to stabilize the Li-Se electrochemistry by constructing a gel polymer electrolyte via in situ gelations of conventional ether-based electrolytes at room temperature. The results demonstrate that the in situ gelated electrolyte helps to build electrochemically stable electrode/electrolyte interfaces and promote the efficient transfer of charge carriers across the interface. Compared with the liquid electrolytes, the gelated electrolyte shows improved chemical compatibility with the Li metal anode, which effectively alleviates the unfavorable side reactions and dendrite formation at the anode/electrolyte interface, and the polyselenide shuttle from the cathode to the anode. As a result, the Li-Se battery shows a higher Coulombic efficiency and improved cycling performance.

Cephalodiones A-D (1-4), the first example of C19 -norditerpenoid dimers, were isolated and fully characterized from a Cephalotaxus plant. These new skeletal natural products shared a unique tricyclo[6.4.1.12,7 ]tetradeca-3,5,9,11-tetraene-13,14-dione core that was capped in both ends with rigid multicyclic ring systems either C2 -symmetrically or asymmetrically. Compounds 1-4 were proposed to be biosynthetically produced by the [6+6]-cycloaddition of two identical C19 -norditerpenoid troponoids, which was validated by the semisyntheses of dimers 2-4. Moreover, some compounds showed significant inhibition on Th17 cell differentiation.

β-N-acetylhexosaminidases have gained much attention for synthesis of functional oligosaccharides, but the relatively low conversion ratio limited their industrial applications. A β-N-acetylhexosaminidase gene (CmHex187) from Catenibacterium mitsuokai was successfully expressed in Escherichia coli. The recombinant enzyme (CmHex187) was purified, biochemically characterized and subjected to the synthesis of human milk oligosaccharides (HMOs). CmHex187 displayed optimal pH and temperature of 5.5 and 45 °C, respectively. The enzyme showed strong transglycosylation activity, as it efficiently catalyzed the synthesis of an important component of HMO lacto-N-triose II (LNT2) using 0.015 M p-nitrophenyl N-acetyl-β- d -glucosaminide and 1.2 M lactose at pH 7.0 and 60 °C for 1.5 h, with a high conversion ratio of 44.3 %. The formed LNT2 promoted the growth of tested Lactobacillus and Bifidobacteria strains. The excellent enzymatic properties and high LNT2 synthesis ability of CmHex187 may make it a good candidate in LNT2 production.

Oil and organic pollutants removal becomes an efficient solution to dispose of industrial oily and textile dye wastewater. This study proposes a lotus leaf-like bionic nanofibrous membrane with underwater superoleophobic for highly efficient oil-water separation. Papillary structure of the bionic membrane is formed by electrospraying of PVDF and TiO2 solutions on the surface of beaded-structure PVDF/TiO2 membrane. Dopamine is then decorated on the resultant PVDF/TiO2 membrane by in situ polymerization to be with hydrophilic-underwater oleophobic property for highly efficient oil-water separation. This bionic membrane has > 99 % oil-water separation efficiency, and high flux of 1389 ± 67 L m−2 h−1. Its contact angle of underwater petroleum ether and dichlomethane reaches 155° and 152°, respectively. Moreover, it has excellent water transport capacity, photocatalytic property, as well as high separation efficiency and flux even after 5-cycle filtration. This bionic nanofibrous membrane will become a promising candidate in clean production, industrial oil/water separation, water purification and efficient liquid transmission.

To explore candidate fungicides from plant secondary metabolites, 16 novel obovatol-type phenazine derivatives were semi-synthesized from obovatol isolated from the leaves of Magnolia obovata Thunb. The antifungal activity of synthesized compounds was investigated in vitro against four phytopathogenic fungi using the spore germination method. The bioassay results showed that eight derivatives (8b, 8g, 8h–k, 8i′, and 8k′) exhibited better antifungal activity against Fusarium solani than two positive controls, especially compounds 8b (IC50 = 64.61 μg mL−1) and 8i′ (IC50 = 79.97 μg mL−1) showed pronounced inhibition of spore germination activity against F. solani. They could be used as lead compounds for further structural optimization. Additionally, the preliminary structure-activity relationships (SARs) illustrated that the introduction of a benzene ring monosubstituted with electron-withdrawing groups into the obovatol scaffold could lead to potentially antifungal compounds.

Light is the most important environmental cue signaling the transition from skotomorphogenesis to photomorphogenesis, thus affecting plant development and metabolic activity. How the light response mechanisms of maize seedlings respond to fluctuations in the light environment has not been well characterized to date. In this study, we built a gene coexpression network from a dynamic transcriptomic map of maize seedlings exposed to different light environments. Coexpression analysis identified ten modules and multiple genes that closely correlate with photosynthesis and characterized hub genes associated with regulatory networks, duplication events, domestication and improvement. In addition, we identified that 38% of hub genes underwent duplication events, 74% of which are related to photosynthesis. Moreover, we captured the dynamic expression atlas of gene sets involved in the chloroplast photosynthetic apparatus and photosynthetic carbon assimilation in different light environments, which should help to elucidate the key mechanisms and regulatory networks that underlie photosynthesis in maize. Insights from this study provide a valuable resource to better understand the genetic mechanisms of the response to fluctuations in the light environment in maize.

Exposure to prolonged or excessive noise has been shown to cause a range of health problems. In this study, flexible sandwich composites (FSCs) with excellent sound absorption and mechanical properties were designed and fabricated by a one-step foaming process. The compound fabric as composite panel and fabric sequence contacted with PU foam has been designed and optimized for excellent cushioning and sound absorption properties. In comparisons of three processing methods for fabricating compound fabrics as reinforced panels of FSCs, punching/hot pressing was found to be the most effective method. Through experiments, the L (low-melting polyethylene terephthalate nonwoven fabric, LPNF) -W (warp-knitted spacer fabric, WKSF) -F (flexible polyurethane foam, FPF) composites had the best performance, reaching the sound absorption coefficient of 0.997 (1000 Hz), 107.77 KPa in compression modulus, 6541 N in maximum impact contact force and 44.68% in impact energy absorption. Morphological study revealed that the transition region formed by FPF and WKSF played a vital role in the L-W-F structure. In that region, small cavities and complex porous paths were observed that effectively improved the sound absorption and cushioning properties by dissipating the stress wave and sound wave level-to-level.

Two organic cages have been prepared in situ in water through the 2 + 3 hydrazone coupling of two pyridinium-derived trialdehydes and oxalohydrazide. The highly water-soluble cages encapsulate and solubilize linear neutral molecules. Such encapsulation has been applied for the promotion of both two- or three-component hydrazone condensation in water. For two-component reactions, the yields of the resulting monohydrazones are increased from 5-10 to 90-96%. For three-component reactions of hydrazinecarbohydrazide with 11 aromatic aldehydes, in the presence of the organic cages, the bihydrazone products can be produced in 88-96% yields. In contrast, without the promotion of the organic cages, 9 of the reactions do not afford the corresponding dihydrazone product.

Phytoliths are microscopic particles of amorphous silica produced by plants that have vital importance for environmental change and carbon sequestration. This study investigated phytoliths and their morphotype assemblages, and phytolith-occluded carbon (PhytOC) along a marsh degradation gradient to clarify the significance of phytoliths for evaluating carbon sequestration dynamics during marsh degradation on the Zoige Plateau, China. Soil samples from non-degraded marsh (NDM), lightly degraded marsh (LDM), moderately degraded marsh (MDM), and seriously degraded marsh (SDM) were collected. Soil phytolith shape and PhytOC were determined using heavy liquid suspension, microscope observations, and alkali-solution spectrophotometry. The dominant phytolith morphotypes among the 15 identified in the soils from the differently degraded marshes were lanceolate, rectangular, and elongate, which originated from Poaceae and Cyperaceae. Soil phytolith morphotype assemblages show potential for studying past vegetation and climatic succession in alpine wetlands. The soil phytolith and PhytOC content exhibited no significant differences between the NDM and LDM samples. Compared with the NDM soil, phytolith content was significantly lower in the MDM (33.8–58.8%) and SDM (52.7–65.4%) soils, respectively, and PhytOC content was also significantly lower (by 31.0–57.1% and 47.5–74.4%, respectively). The soil phytolith and PhytOC content decreased significantly with soil depth, especially once the marsh has become moderately degraded. Alpine marsh degradation reduced the accumulation of soil PhytOC by decreasing the PhytOC input flux, thereby altering the long-term carbon sequestration mechanism of phytoliths in this alpine-marsh wetland ecosystem.

Verticillium wilt is a vascular disease caused by Verticillium dahliae, which has a serious impact on the yield and quality of eggplant. MiRNAs regulates plant growth, development, environmental adaptation and other life activities by controlling the expression of target genes. Although miRNAs have been systematically studied by high-throughput sequencing in eggplant (Solanum melongena L.), their target genes are not identified systematically, which would provide the basis for exploring the mechanism of miRNA mediated gene regulation in response to Verticillium wilt of eggplant. In this study, degradome sequencing was performed using two libraries separately prepared from mock-inoculated and V. dahliae-inoculated seedlings of eggplants. A total of 122 target genes for 49 miRNAs families were identified. Of them, 62 target genes were significantly induced by V. dahliae, including 34 targets were found only in the inoculated seedlings library and 28 targets were shown to be differentially expressed between both two libraries. Further analysis showed that a conserved miRNA could target various genes ranging from one up to 15 or a target gene could be cleaved by 1–5 different miRNAs. QRT-PCR analysis on five miRNAs and their target genes confirmed the reliability of the degradome sequencing data. GO analysis revealed that target genes owned diverse biological functions and transcription regulation was the largest functional category. Analysis on KEGG showed that target genes were mainly involved in plant-pathogen interaction pathway and plant hormone signal transduction pathway to resist disease. This result will provide basic information for further studying the regulatory mechanism of eggplant miRNAs in response to Verticillium wilt infection.

Hundreds of insect genome sequences have been reported; however, most sequencing projects have not determined the sex chromosomes, and no Y chromosomes from a heterometabolous insect have been identified and characterized to date. The brown planthopper (Nilaparvata lugens Stål) is the most economically damaging pest to rice and is also an ideal research subject for paddy ecology and functional genomics. We previously assembled a draft female genome mainly using second-generation sequencing technologies, with a contig N50 of only 24 kb, due to the large size and excessive repetitive regions in the N. lugens genome. Here, we utilize third-generation sequencing technologies and Hi-C data to generate a high-quality male N. lugens assembly with a contig N50 of 1.01 Mb, a scaffold N50 of 69.96 Mb and more than 95.6% of the assembled bases located on 16 chromosomes. Fourteen autosomes and two sex chromosomes (X + Y) were identified, filling in the gap related to the Y chromosome in heterometabolous insects. A total of 18,021 protein-coding genes and 6423 long-noncoding RNAs were predicted with full-length cDNA sequencing data. All 315 of the Y chromosome genes (Y-genes) were derived from autosomal and X-chromosome duplications. Large-scale RNA interference (RNAi) experiments were conducted against the N. lugens Y-genes, demonstrating that 7 Y-genes were essential for normal BPH development or male organ development, suggesting the importance of Y-genes. The first identified Y chromosome in heterometabolous insects will help gain more insight into sex determination, fertility and chromosome evolution.

Potassium (K) deficiency is widespread in Alfisols on which tea is grown, and quantifying the availability of K to the tea plants is important in designing fertilizer regimes and in ensuring that tea production systems remain sustainable. In this study, the contents of available K, its release characteristics, and the composition of K-bearing minerals were determined for Alfisols on which tea had been grown for 5, 10, 15, or 30 years. The contents of exchangeable K (EK), non-exchangeable K (NEK), K extracted with sodium tetraphenylboron, release threshold values of total labile K, and equilibrium K concentration increased as the age of the plantation increased. However, the content of EK even in the oldest plantations was far below the critical value for K deficiency (80 mg kg−1). The concentration of total labile K was higher than that of EK irrespective of the age of the plantation, which points to serious exhaustion of NEK reserves. Furthermore, compared to older plantations, the younger plantations contained less of illite and chlorite and more of kaolinite and vermiculite in the clay fraction of the soils. Chlorite and illite was significantly positive correlated to available K either in the surface layer (0–15 cm) or in the deeper layer (15–30 cm), whereas kaolinite was significantly and negatively correlated to available K at both depths. Although tea plantations increased the reserves of soil available K, the increase was not enough either to overcome the deficiency of available K—which continues to be extremely severe—or to prevent the distortion of clay minerals in Alfisols. Adequate inputs of K are therefore essential for increasing the inherent capacity of the Alfisols to supply K and, in turn, to obtain high yields and superior-quality tea.

Electrochemical conversion reactions provide more selections for Na-storage materials, but the reaction suffers from low reversibility and poor cyclability. Introducing an electrochemically inactive component is a common strategy, but the effect is quite limited since it could not stabilize the structure during long-term cycling. In this study, a new approach is developed using an amino group-functioned hyperbranched polymer (AHP) as a template and electrode additive for the design of high-performance FeSe2-AHP composite with chemical interaction. The assembled FeSe2-AHP composite nanoneedles were prepared by the selenylation of FeS-AHP composite microflowers and entirely inherit the polymer network from the precursor. The amino groups of AHP in composite coordinate with iron cations to achieve uniform polymer dispersion in the composite, and maintain the molecular level mixed state during the long-term cycling. Moreover, the in-situ constructed uniform 3D elastic polymer network effectively accommodates volume expansion and alleviates nanoparticle aggregation during sodiation/de-sodiation. FeSe2-AHP composite provides a superior rate capability (584.8 mAh·g−1 at 20 A·g−1) and a remarkable cyclability with a capacity retention rate of 93.3% after 2,000 cycles. FeSe2-AHP composite shows a high pseudocapacitive behavior for the abundant nanometer interface established by AHP, enhancing the solid-state Na+ diffusion. The FeSe2-AHP anode is also compatible with Na3V2(PO4)3/C cathode in a full Na-ion battery, which provides a high-power performance (powering 51 LEDs). The work herein highlights an innovative and efficient strategy for conversion-type material design and demonstrates the function of chemical interaction of polymer additive in the enhancement of long-term cyclability for conversion electrode.

A deep ensemble convolutional neural network (CNN) model to inspect printed circuit board (PCB) board dual in-line package (DIP) soldering defects with Hybrid-YOLOv2 (YOLOv2 as a foreground detector and ResNet-101 as a classifier) and Faster RCNN with ResNet-101 and Feature Pyramid Network (FPN) (FRRF) achieved a detection rate of 97.45% and a false alarm rate (FAR) of 20%–30% in the previous study [34] . However, applying the method to other production lines, environmental variations, such as lighting, orientations of the sample feeds, and mechanical deviations, led to the degradation in detection performance. This article proposes an effective self-adaption method that collects “exception data” like the samples with which the Artificial Intelligent (AI) model made mistakes from the automated optical inspection inference edge to the training server, retraining with exceptions on the server and deploying back to the edge. The proposed defect detection system has been verified with real tests that achieved a detection rate of 99.99% with an FAR 20%–30% and less than 15 s of inspection time on a resolution $7296 \times 6000$ PCB image. The proposed system has proven capable of shortening inspection and repair time for online operators, where a 33% efficiency boost from the three production lines of the collaborated factory has been reported [6] . The contribution of the proposed retraining mechanism is threefold: 1) because the retraining process directly learns from the exceptions, the model can quickly adapt to the characteristic of each production line, leading to a fast and reliable mass deployment; 2) the proposed retraining mechanism is a necessary self-service for conventional users as it incrementally improves the detection performance without professional guidance or fine-tuning; and 3) the semiautomatic exception data collection method helps to reduce the time-consuming manual labeling during the retraining process.

A modified cross-coupling low-triggering dual-polarity silicon controlled rectifier ( ${m}$ -CLTdSCR) for on-chip electrostatic discharge (ESD) protection is developed. Cross-coupling mechanism can effectively reduce the trigger voltage of the proposed structure. A lower leakage is achieved by replacing NMOS with PMOS and changed connection, and this also effectively reduces the parasitic capacitance of ${m}$ -CLTdSCR between anode and cathode. The new structure shows low-triggering voltage ~3.46 V, low leakage ~0.46 nA under normal operation condition, and low parasitic capacitance ~190 fF at zero bias. As such, the proposed ${m}$ -CLTdSCR is an attractive device for radio frequency integrated circuits (RFICs) ESD protection.

Two new benzo[de]isoquinoline derivatives, 4-phenyl-benzo[de]isoquinoline-1,3-dione (1) and 4-(4-hydroxyphenyl)-benzo[de]isoquinoline-1,3-dione (2), were isolated from 70% ethanol extract of the rh...

Developing a high dielectric constant (er) polymer dielectrics with low dielectric loss and high thermal conductivity (TC) is still continuous demands for advanced electrical power systems. Herein, nickel (Ni) particles were encapsulated by silica (SiO2) via a sol–gel process using sodium silicate as a precursor, and the obtained core–shell Ni@SiO2 powders were blended into poly(vinylidene fluoride) (PVDF) to investigate the effects of SiO2 insulating layer and its thickness on dielectric properties and TC of composites. Compared with pristine Ni, the Ni@SiO2/PVDF composites exhibit a superior er, and remarkably suppressed loss and conductivity, attributable to the SiO2 interlayer between the core Ni particles which effectively prevents them from direct contacts and significantly reduces the leakage loss. Moreover, the Ni@SiO2/PVDF composites still possess a high TC owing to the restrained thermal interfacial resistance and enhanced interfacial compatibility between the fillers and the matrix. The developed Ni@SiO2/PVDF composites with high k and TC but low loss are potential for microelectronic industry.

Since nonlinearity is critical to silicon piezoresistive pressure sensors, this paper combined theoretical analysis and simulation to study the effect of changing the longitudinal resistance (RL) and transverse resistance (RT) on the nonlinearity of pressure sensors. When initial longitudinal resistance (RL0) is larger than initial transverse resistance (RT0) and the difference is within a certain range, the nonlinearity of the pressure sensor can be effectively reduced. And based on this discovery, a method of an asymmetric Wheatstone bridge for optimizing nonlinearity of piezoresistive pressure sensors was proposed, which could reduce the nonlinearity from 10–3 to 10–6 order of magnitudes in the simulation.

A novel sulfonyl radical triggered selective iodosulfonylation and bicyclization of 1,6-dienes has been described for the first time. High selectivity and efficiency, mild reaction conditions, excellent functional group compatibility, and broad substrate scope are the attractive features of this synthetic protocol, which provides a unique platform for precise radical cyclization.

Corrosion resistance of titanium (Ti) alloys is closely connected with their microstructure which can be adjusted and controlled via different annealing schemes. Herein, we systematically investigate the specific effects of annealing on the corrosion performance of Ti-6Al-3Nb-2Zr-1Mo (Ti80) alloy in 3.5 wt.% NaCl and 5 M HCl solutions, respectively, based on open circuit potential (OCP), potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), static immersion tests and surface analysis. Results indicate that increasing annealing temperature endows Ti80 alloy with a higher volume fraction of β phase and finer α phase, which in turn improves its corrosion resistance. Surface characterization demonstrates that β phase is more resistant to corrosion than α phase owing to a higher content of Nb, Mo, and Zr in the former; additionally, the decreased thickness of α phase alleviates segregation of elements to further restrain the micro-galvanic couple effects between α and β phases. Meanwhile, the influential mechanisms of environmental conditions on corrosion of Ti80 alloy are discussed in detail. As the formation of a highly compact and stable oxide film on surface, annealed Ti80 alloys exhibit a low corrosion current density (10−6 A/cm2) and high polarization impedance (106 Ω⋅ cm2) in 3.5 wt.% NaCl solution. However, they suffer severe corrosion in 5 M HCl solution, resulting from the breakdown of native oxide films (the conversion of TiO2 to aqueous Ti3+), active dissolution of substrate Ti to aqueous Ti3+ and existence of micro-galvanic couple effects. Those findings could provide new insights to designing Ti alloys with high-corrosion resistance through microstructural optimization.

Potassium-ion batteries (PIBs) that serve as low-cost and large-scale secondary batteries are regarded as promising alternatives and a supplement to lithium-ion batteries. Hybrid active materials feature the synergistic merits of individual components to overcome the sluggish kinetics of K+ insertion and structural deterioration of electrodes for PIBs. We report herein that a highly stable hybrid anode active material, an amorphous MnOxPy (a-MnOxPy) overlayer coating on a Ni5P4 film, is grown on carbon fabric cloth (CF) through a phosphidation reaction to obtain the integrated a-MnOxPy/Ni5P4/CF anode by simple phosphidation treatment. The optimized a-MnOxPy/Ni5P4/CFP anode delivers a high reversible specific depotassiation capacity of 398.8 mA h g−1 at 0.3 A g−1 after 100 cycles and acquires an excellent rate capability together with high cycling stability with capacities of 225.1 and 175.3 mA h g−1 at 5 and 10 A g−1 after 5000 cycles, respectively. The amorphous a-MnOxPy-45 overlayer and the porous features of the a-MnOxPy-45/Ni5P4 provide sufficient stress buffer and thus greatly accommodate large volume changes during potassiation/depotassiation. The hybrid interface between a-MnOxPy and Ni5P4 and favorable conductivity of the formed phosphides promote the charge transport and K+ storage kinetics. Also, the a-MnOxPy/Ni5P4/CF//K4Fe(CN)6 PIB full cell exhibits an initial discharge capacity of 343.9 mA h g−1 at 0.2 A g−1 and maintains 331.9 mA h g−1 after 100 cycles.