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A robust solvothermal-driven solid-to-solid transition strategy is developed to craft tartaric acid-capped ultrafine SnO2 encapsulated in graphene with outstanding lithium and sodium storage reversibility due to effectively inhibited Sn coarsening.

Nano-polycrystalline Sn2S3/Sn3S4/FeS/Fe7S8 sulfides anchored on graphene were synthesized via annealing SnS2 and Fe followed by homogeneously combining them with exfoliated graphite.

Perfect absorption is realized by an anapole metamaterial composed only of oxide ceramics. The tolerance limits of metamaterial devices to an extreme environment, especially in a high-temperature oxidation environment, are being broken.

The tunneling current through the single-molecule junctions principally offers the ultimate solution for chemical and biochemical sensing via the interactions between probes and target analytes at the single-molecule level. However, it remains unexplored to achieve the sensitive and selective detection of targeted analytes using single-molecule junction techniques due to the challenge in quantitative evaluation of sensing sensitivity and selectivity. Herein, we demonstrate a single-molecule tunneling sensor for the highly sensitive and selective detection of nitrobenzene explosives using scanning tunneling microscope break junction (STM-BJ). Taking advantage of π-π stacking interactions between the molecular probes and nitrobenzene explosives, we use a spectral clustering algorithm to assign the signal of probes and π-stacked probes for sensitively detecting the targeted analytes and the distinguishable conductance change of probes when interacting with different nitroaromatic explosive compounds for selective detection. We find that pronounced conductance changes up to 0.8 orders of magnitude when the probes interact with TNT. Also, we obtain a sensitivity of up to ∼10 pM for TNT and high sensitivity for eight TNT analogues. Combined with theoretical calculations, we discover that the harness of the destructive quantum interference of the probe M1OH after interacting with TNT leads to high selectivity in sensing with TNT. Our work demonstrates the great potential of the single-molecule tunneling current for environmental sensing molecules with high selectivity and sensitivity.

The nitrogen doping of graphene leads to graphene heterojunctions with a tunable bandgap, suitable for electronics, electrochemical, and sensing applications. However, the microscopic nature and charge transport properties of atomic-level nitrogen-doped graphene are still unknown, mainly due to the multiple doping sites with topological diversities. In this work, we fabricated the atomically well-defined N-doped graphene heterojunctions and investigated the cross-plane transport through these heterojunctions to reveal the effects of doping on their electronic properties. We found that different doping number of nitrogen atoms leads to a conductance difference of up to ~288, and the conductance of graphene heterojunctions with nitrogen-doping at different positions in the conjugated framework can also lead to a conductance difference of ~170. Combined ultraviolet photoelectron spectroscopy measurements and theoretical calculations reveal that the insertion of nitrogen atoms into the conjugation framework significantly stabilizes the frontier molecular orbitals, leading to a change in the relative positions of HOMO and LUMO to the Fermi level of the electrodes. Our work provides a unique insight into the role of nitrogen doping on the charge transport through graphene heterojunctions and materials at the single atomic level.

Introduction: Acute acquired concomitant esotropia (AACE) has been increased dramatically in myopia. To clarify whether fusional vergence dysfunctions exist in AACE with myopia, and to explore the relationship between fusional vergence and myopia in AACE Methods: A prospective clinical study. Adult AACE patients as well as controls (aged ≥18 years) both with myopia were prospectively recruited from October 2016 to August 2021. Refractive error and fusional divergence and convergence amplitude at distance were measured, as determined with a comprehensive refractor. The main outcome measures were the real value of the fusional divergence amplitude (calculated by subtracting the break point value from the angle of deviation) and the real value of the fusional convergence amplitude (calculated by subtracting the angle of deviation from the break point value). Two-sided p value of less than 0.05 was considered to indicate statistical significance. Results: Fusional vergence consisting of fusional divergence and fusional convergence in patients with AACE of adulthood were different from the controls (p

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

It is possible to improve the machinability of aluminum nitride-hexagonal boron nitride (AlN-h-BN) ceramics while maintaining high strength and high thermal conductivity. The composite ceramics with 0–30 wt% BN as secondary phase were prepared by hot pressed sintering, using yttrium oxide (Y2O3) as sintering aid. The phase composition, density, microstructure, mechanical properties, thermal conductivity, and dielectric properties were investigated. The sintering additives were favorable to purify the grain boundaries and improve densification, reacting with oxide impurities on the surface of raw material powder particles. The optimum BN content improved the flexural strength and fracture toughness of composite ceramics with 475 MPa and 4.86 MPa·m1/2, respectively. With increasing the amount of BN, the thermal conductivity and hardness of composites gradually decreased, but the minimum value of thermal conductivity was still 85.6 W·m−1·K−1. The relative dielectric constant and dielectric loss tangent of the samples ranged from 6.8 to 8.3 and from 2.4 × 10−3 to 6.4 × 10−3, respectively, in 22–26 GHz.

Recent years have witnessed the fabrication of various non-covalent interaction-based molecular electronic devices. In the non-covalent interaction-based molecular devices, the strength of the interfacial coupling between molecule and electrode is weakened compared to that of the covalent interaction-based molecular devices, which provides wide applications in fabricating versatile molecular devices. In this review, we start with the methods capable of fabricating graphene-based nanogaps, and the following routes to construct non-covalent interaction-based molecular junctions with graphene electrodes. Then we give an introduction to the reported non-covalent interaction-based molecular devices with graphene electrodes equipped with different electrical functions. Moreover, we summarize the recent progress in the design and fabrication of new-type molecular devices based on graphene and graphene-like two-dimensional (2D) materials. The review ends with a prospect on the challenges and opportunities of non-covalent interaction-based molecular electronics in the near future.

Increasing the availability of π-electron in graphitic carbon nitride (g-C3N4) can reduce the band gap and thus enhance the photocatalytic hydrogen (H2) generation activity upon exposure to visible light. However, such strategy has not yet been largely applied to increase the H2 generation of g-C3N4. Herein, we successfully increased the amount of π-electron in g-C3N4 by incorporating π-electron-rich benzene rings through copolymerization of melamine and trimesic acid in air. The incorporation of benzene rings not only extends the light absorption of g-C3N4 to 650 nm, but also improves the electrical conductivity due to delocalization of π electrons in benzene rings. As a result, a 3.4 times enhancement of photocatalytic H2 generation was achieved from the g-C3N4 with benzene ring incorporation in comparing with that of pristine g-C3N4. More interestingly, H2 generation still occurs under irradiation of the light of λ ≥ 490 nm, above the absorption edge of pristine g-C3N4 (∼ 460 nm), illustrating the positive effectiveness of incorporated benzene rings on enhancing the H2 generation capacity of g-C3N4. The present work manifests the advantages of increasing π-conjugated electrons on designing highly active g-C3N4 photocatalysts.

Sub-5 nm monodispersed metal oxides have been attracting much attention in energy storage due to their large electrolyte ion-accessible surface areas and high specific capacities. However, the high surface free energy of ultrasmall nanoparticles inevitably results in their serious aggregation, leading to degraded electrochemical activities and poor cycling stability. Herein, a two-stage microimpinging stream reactor (TS-MISR) strategy that combines a first homogeneous premixing stage with a subsequent microimpinging stream reacting stage has been constructed for the controllable synthesis of Ni–Co–O/RGO composites (NCG). Benefiting from the enhanced micromixing efficiency and better process control of TS-MISR, monodispersed ultrasmall Ni–Co–O particles (3–4 nm) are evenly grown on the RGO flakes to generate a large specific surface area (293.2 m2 g−1), quantities of desirable mesopores (2–4 nm), as well as a strong synergistic effect between Ni–Co–O particles and conductive RGO flakes, hence providing more superficial electroactive sites, fast electron transfer and short diffusion paths for electrolyte ions to participate in faradaic redox reactions. The as-prepared NCG-MM exhibits a large specific capacity of 912.4 C g−1 (capacitance of 2281 F g−1) at the current density of 1 A g−1, good rate capability and cycling stability. Coupled with the activated carbon (AC) negative electrode, the assembled pouch-type NCG//AC asymmetric supercapacitor displays a prominent areal energy density (0.898 mW h cm−2 at 0.8 mW cm−2) and an excellent cycling stability (∼90.5% capacity retention after 8000 cycles). In addition, this strategy opens up an important prospect for the controllable synthesis of monodispersed metal oxide/graphene composites for application in batteries, sensors and catalysis.

To examine how two dominant species coexist within a tidal wetland in the Yellow River Delta, we studied the spatial distribution patterns and ecological relationships of Tamarix chinensis and Suaeda salsa. We also analyzed the relationship between these two plant species and soil chemical properties. Nine quadrats were established, and aerial photography was carried out in July 2018 in the study area to investigate plants and soil. Results showed that T. chinensis showed an aggregation distribution at scales of 0-10 m, 0-30 m, and 0-50 m from the sea to inland. Unlike T. chinensis, S. salsa showed an aggregation distribution at approximately 0-50 m in the study area, which meant the aggregation distributions of T. chinensis and S. salsa were found at different scales and S. salsa tended to aggregate distribution compared with T. chinensis. Meanwhile, T. chinensis and S. salsa had negative correlations far from the sea at a scale of 0-20 m and at the offshore area at a scale of 0-30 m. However, in the intermediate area, S. salsa and T. chinensis showed a positive correlation at a scale of 0-30 m. In general, the relationship between the two groups tends to be negatively correlated in a small range. Given that the tidal action decreased from the sea to inland, the driving factors of population aggregation gradually changed from tidal flooding to an interspecific relationship. The different characteristics of the different species may also have had an effect. And the aggregation of adult plant species had a beneficial impact on the establishment and growth of seedlings and plants. Furthermore, soil properties comprised complex actions including environmental conditions and ecological processes. The soil chemical properties such as soil salinity and nutrients were also influenced by the species' canopy.

BACKGROUND: Methyl levulinate (ML) is a promising green candidate for bio‐based diesel fuels and fuel additives. An effective method for synthesizing ML from levulinic acid (LA) catalyzed by cheap metal salt catalyst under mild conditions was developed. A series of metal salts were screened for the synthesis of ML from LA, and aluminum chloride was identified as a suitable catalyst for this process. RESULTS: The effects of catalyst loading, the molar ratio of methanol to LA, reaction temperature and reaction time on LA conversion and ML yield were investigated. The response surface method was used to optimize the process, and the model validation experiment showed that the predicted values corresponded well with the actual ones. Under the optimum conditions of reaction temperature 343 K, reaction time 1.5 h, aluminum chloride 1.14 g and molar ratio of methanol to LA 8:1, a high ML yield of 95.0 mol% could be obtained. Moreover, a kinetic model was proposed to evaluate the reaction process at a temperature range of 30–70 °C. The first‐order pseudo model was considered most suitable (R² > 0.99), and the activation energy of the reaction Eₐ was estimated to be 32.28 kJ mol⁻¹. Investigation of the reuse of the catalyst revealed that it retained good catalytic activity after repeated use for ten times. CONCLUSION: A green and efficient process of ML production from LA catalyzed by the metal salt aluminum chloride was developed. © 2020 Society of Chemical Industry

The Yellow River Delta wetlands in the Yellow River Delta National Nature Reserve are facing serious degradation due to water scarcity and soil salinization. This study aims to investigate the mechanism of wetland degradation by analyzing the small-scale distribution of soil nutrients and preferential flow transport patterns in the Robinia Pseudoacacia community, which is a typical vegetation community in degraded wetlands. Soil physical and chemical properties based on field staining experiments were analyzed, and indoor solute penetration experiments were conducted to investigate the distribution of soil nutrients and hydrological characteristics. The results showed that the contents of soil organic carbon, organic matter, total nitrogen, and available phosphorus decreased with increasing soil depth, with higher contents in the preferential flow area than in the matrix flow area. Soil organic carbon, organic matter, total nitrogen, total phosphorus, and available phosphorus showed positive correlations with each other, while soil pH and conductivity exhibited negative correlations with the above nutrients. The efflux rate of the Acacia community exhibited a gradual decline as soil depth increased, and the relative concentration of the solution exhibited a non-monotonic pattern of decrease, increase, and subsequent decrease with increasing soil depth. The findings could provide valuable guidance for the restoration and management of degraded wetlands in the Yellow River Delta.

Comprehensive research is conducted on the design and control of the unmanned systems for electric vehicles. The environmental risk prediction and avoidance system is divided into the prediction part and the avoidance part. The prediction part is divided into environmental perception, environmental risk assessment, and risk prediction. In the avoidance part, the conservative driving strategy based on speed restriction is adopted according to the results of risk prediction. Additionally, the core function is achieved through the target detection technology based on deep learning algorithm and the data conclusion based on deep learning method. Moreover, the location of bounding box is further optimized to improve the accuracy of SSD target detection method based on solving the problem of unbalanced sample categories. Software such as MATLAB and Carsim are applied in the system. From the comparison results of the simulations of unmanned vehicles with or without a system, it that the system can provide effective safety guarantee for unmanned driving.

Artificial intelligence approach can be used to solve complicated process problems. A hybrid methodology comprising artificial neural network (ANN) and genetic algorithms (GA) was utilized to model...

Glycerol levulinate ketal (GLK) is a novel biobased chemical compound with great potential for industrial applications, especially in the areas of green solvents and polymeric materials. For the fi...

State-of-the-art molecular electronics focus on the measurement of electrical properties of materials at the single-molecule level. Experimentally, molecular electronics face two primary challenges. One challenge is the reliable construction of single-molecule junctions, and the second challenge is the arbitrary modulation of electron transport through these junctions. Over the past decades, electrochemistry has been widely adopted to meet these challenges, leading to a wealth of novel findings. This review starts from the application of electrochemical methods to the fabrication of nanogaps, which is an essential platform for the construction of single-molecule junctions. The utilization of electrochemistry for the modification of molecular junctions, including terminal groups and structural backbones, is introduced, and finally, recent progress in the electrochemical modulation of single-molecule electron transport is reviewed.

Crystalline metal-organic frameworks of divalent transition metal terephthalate belong to a new kind of high-capacity lithium storage materials. In this paper, CoCl 2 aqueous solution and CoCl 2 ·6H 2 O particles are comparatively used as starting materials to react with aqueous lithium terephthalate (Li 2 TP), resulting in the hierarchical architectures of dihydrate cobalt terephthalate (CoTP·2H 2 O No.1, No.2) by a solution-based π-π stacking self-assembly, respectively. Each of the two hydrated samples, as well as its well-crystallized anhydrous counterpart (CoTP No.1 or No.2), acquire a specific surface area no bigger than 4.5 m 2 g −1 but deliver a reversible capacity no less than 815.0 mAh g −1 at 200 mA g −1 in the 100th cycle. The decreasing order of lithium-storage capability (CoTP·2H 2 O No.1 2 O No.2 −1 , the 350th cycle) of CoTP No.2 structure and indicates a successful approach to the facile preparation of the organic anode material for high-performance lithium-ion batteries.

The ability to rationally design binder-free electrode materials that possess interconnected nanostructures is highly desirable for lithium-ion batteries (LIBs) with long cycling and excellent rate performances. Such electrode containing pores between nanostructures imparts large-area contact with electrolyte, improved electrical conductivity with current collector, and good structural stability and mechanical integrity. Herein, we report, for the first time, outstanding cycling stability and rate performance of CuO electrode in LIBs. CuO nano-labyrinths (NLs) composed of densely interlaced nanowalls on Cu foil are crafted via a facile solution-based etching process. It is notable that macroscopic and mesoscopic pores are found to ubiquitously present among the adjacent CuO nanowalls and within the nanowall, respectively (i.e., forming hierarchically porous CuO NLs). Intriguingly, CuO NLs anodes yield an ultralong cycling stability, that is, a specific capacity of 320 mA h g−1 after 800 cycles without the capacity fading at high current density of 1 A g−1, and an outstanding high-rate performance (up to 30 C). This is a direct consequence of unique synergistic effects of hierarchical pores and interlaced nanostructures. Moreover, a further enhancement of reversible capacity is achieved by deposition Si thin film on the surface of CuO NLs. Such interlaced nanowall-containing structures with hierarchical pores represent an important type of architectures that underpin the development of electrode materials for long cycle-life energy storage devices.

Intermolecular charge transport plays an essential role in organic electronic materials and biological systems. To date, experimental investigations of intermolecular charge transport in molecular materials and electronic devices have been restricted to conjugated systems in which π-π stacking interactions are involved. Herein we demonstrate that the σ-σ stacking interactions between neighbouring non-conjugated molecules offer an efficient pathway for charge transport through supramolecular junctions. The conductance of σ-σ stacked molecular junctions formed between two non-conjugated cyclohexanethiol or single-anchored adamantane molecules is comparable to that of π-π stacked molecular junctions formed between π-conjugated benzene rings. The current-voltage characteristics and flicker noise analysis demonstrate the existence of stacked molecular junctions formed between the electrode pairs and exhibit the characteristics of through-space charge transport. Density functional theory calculations combined with the non-equilibrium Green's function method reveal that efficient charge transport occurs between two molecules configured with σ-σ stacking interactions.

Wetland ecosystem, with their precious natural resources and important ecological functions, is an integral part of the global ecosystem. Preferential flow is a form of water and solute transport that is widely present in all types of soils and has a great impact on nutrient transport and environmental pollution in soils. In this paper, we observe the phenomenon of preferential flow within a wetland ecosystem and discuss the possible effects of preferential flow within a wetland on the wetland ecosystem as a background. We conducted dye tracing experiments outdoors. The preferential flow was qualitative analysis using soil composition. It was found that two types of preferential flow existed in the experimental area, namely finger flow and macropore flow. Quantitative analysis of the preferential flow was performed using PS and Image-Pro Plus software to obtain the intensity data of the preferential flow. The results show that the preferential flow phenomenon in the experimental area is obvious and the preferential-flow intensity data is high. We also found a clear correlation between initial soil–water content, which is an environmental factor characteristic of wetlands, and the preferential-flow data (p = 0.04

Growing populations and industrialization have led to raised wetland ecosystems nitrogen(N) loads. A micro constructed wetland planted with Lythrum salicaria L treating an artificial wastewater was used to investigate the short-term variations in the plant biomass and the removal efficiency of N. Our results showed that the biomass of Lythrum salicaria L. increased rapidly during the experiment due to their extensive root system and vigorous spread, and waterlogged conditions had little effect on the relationship between biomass and the concentration of TN in soil and effluent. Under different waterlogged conditions, the removal rates of TN in the water were all more than 60%, providing a reference for waterlogged conditions used in wetland eutrophication restoration.

Though solar cells are one of the promising technologies to address the energy crisis, this technology is still far from commercialization. Thermoelectric materials offer a novel opportunity to convert energy between thermal and electrical aspects, which show the feasibility to improve the performance of solar cells via heat management and light harvesting. Polymer–inorganic thermoelectric nanocomposites consisting of inorganic nanomaterials and functional organic polymers represent one kind of advanced hybrid nanomaterials with tunable optical and electrical characteristics and fascinating interfacial and surface chemistry. During the past decades, they have attracted extensive research interest due to their diverse composition, easy synthesis, and large surface area. Such advanced nanomaterials not only inherit low thermal conductivity from polymers and high Seebeck coefficient, and high electrical conductivity from inorganic materials, but also benefit from the additional interface between each component. In this review, we provide an overview of interfacial chemistry engineering and electrical feature of various polymer–inorganic thermoelectric hybrid nanomaterials, including synthetic methods, properties, and applications in thermoelectric devices. In addition, the prospect and challenges of polymer–inorganic nanocomposites are discussed in the field of thermoelectric energy.

In recent years, scholars have paid increased attention to the ecological role of crab burrows, particularly their impact on the hydrological processes of saltmarsh wetlands. This study aims to investigate the influence of crab burrows on soil water and salt transport and to understand the ecological significance of crab burrows in coastal wetlands from the perspective of ecohydrological processes. We combined a field sample survey and an indoor soil column infiltration experiment to analyze the differences in infiltration time, soil water content, and soil electrical conductivity (EC) between different experimental groups. Consequently, the results showed that the size of crab burrow diameter varies significantly in different areas of the coastal wetland, influenced by tidal creek and sea-land distances, with larger burrow diameters in areas around 5 m from the tidal creek. Large-diameter burrows (2.5 cm × 6) are more conducive to salt transport due to their preferential water conductivity to the underlying soil vertically, small-diameter burrows (0.5 cm × 6) could promote water infiltration uniformly and maintain good soil water retention capacity. This study's results provide insights into the hydrological connectivity and spatial distribution of salinity in coastal wetlands. Additionally, the positive impact of burrows on the water-salt environment of coastal wetland sediments may also provide new ideas for coastal wetland restoration.