An all-perovskite oxide heterostructure composed of SrSnO3/Nb-doped SrTiO3 was fabricated using the pulsed laser deposition method. In-plane and out-of-plane structural characterization of the fabricated films were analyzed by x-ray diffraction with θ-2θ scans and φ scans. X-ray photoelectron spectroscopy measurement was performed to check the film’s composition. The electrical transport characteristic of the heterostructure was determined by applying a pulsed dc bias across the interface. Unusual transport properties of the interface between the SrSnO3 and Nb-doped SrTiO3 were investigated at temperatures from 100 to 300 K. A diodelike rectifying behavior was observed in the temperature-dependent current-voltage (IV) measurements. The forward current showed the typical IV characteristics of p-n junctions or Schottky diodes, and were perfectly fitted using the thermionic emission model. Two regions with different transport mechanism were detected, and the boundary curve was expressed by ln I = -1.28V - 13. Under reverse bias, however, the temperature- dependent IV curves revealed an unusual increase in the reverse-bias current with decreasing temperature, indicating tunneling effects at the interface. The Poole-Frenkel emission was used to explain this electrical transport mechanism under the reverse voltages.

Ship collision accidents not only endanger the safety of ships and personnel, but also may cause serious marine environmental pollution. To solve this problem, advanced technologies have been developed and applied in the field of intelligent ships in recent years. In this paper, a novel path planning algorithm is proposed based on particle swarm optimization (PSO) to construct a decision-making system for ship's autonomous collision avoidance using the process analysis which combines with the ship encounter situation and the decision-making method based on ship collision avoidance responsibility. This algorithm is designed to avoid both static and dynamic obstacles by judging the collision risk considering bad weather conditions by using BP neural network. When the two ships enter a certain distance, the optimal collision avoidance course and speed of the ship are obtained through the improved collision avoidance decision-making method. Finally, through MATLAB and Visual C++ platform simulations, the results show that the ship collision avoidance decision-making scheme can obtain reasonable optimal collision avoidance speed and course, which can ensure the safety of ship path planning and reduce energy consumption.

With the continuous development of science and technology, unmanned ship has gradually become a hot spot in the field of marine research. In practical applications, unmanned ships need to have long-range navigation and high efficiency, so that they can accurately perform tasks in the marine environment. As one of the key technologies of unmanned ship, path planning is of great significance to improve the endurance of unmanned ship. In order to meet the requirements, this paper proposes a path planning method for long distance unmanned ships based on reinforcement learning angle precedence ant colony improvement algorithm. Firstly, canny operator is used to automatically extract navigation environment information, and then MAKLINK graph theory is applied for environment modelling. Finally, the basic ant colony algorithm is improved and applied to the path planning of unmanned ship to generate an optimal path. The experimental results show that, compared with the traditional ant colony algorithm, the path planning method based on the improved ant colony algorithm can achieve a voyage duration of nearly 7 km for unmanned ships under the same sailing environment, which has certain practicability and popularization value.

In order to solve the problem of improper thrust distribution of each thruster of underwater vehicle, the PSO optimization algorithm is used to solve the problem of thrust distribution. According to the spatial layout of the thruster, the algorithm model of the underwater vehicle propulsion system is established. The thrust input is carried out under the broken line search trajectory, and the simulation verifies the thrust allocation results of the PSO algorithm and the traditional pseudo-inverse method. The simulation results show that compared with the traditional algorithm. First of all, the PSO algorithm can set the physical threshold for each thruster to prevent the thruster from having too much thrust. Secondly, it can ensure that the thruster can turn with a reasonable torque to prevent the robot from drifting due to the large thrust gap. This paper provides a theoretical reference for thrust distribution of underwater salvage robot, and has practical engineering significance.

The carbon-containing molecule can be used as an NMR probe to explore the acidic and structural features of various catalytic materials. Thereinto, although mesityl oxide (MO) has been extensively employed to determine the acidity of solution and ionic liquid systems, could it be utilized to characterize the acidic properties of solid acid catalysts? In this work, on the basis of a series of isolated Brønsted and Lewis acid models with varied acid strengths, the adsorption configurations and corresponding 13C chemical shifts of adsorbed MO molecules have been comprehensively studied by means of a theoretical investigation approach. Among them, both the 13C chemical shift difference between β and α carbon atoms (Δδ), and the 13C chemical shift of β carbon atoms (δ13Cβ) in adsorbed MO molecules were explicitly demonstrated to be closely related to the intrinsic acid strength of Brønsted acid sites. These correlations could be utilized to quantitatively scale the Brønsted acid strength of solid acid catalysts. Besides, a moderate relationship was theoretically derived for the relevant 13C NMR parameters and intrinsic Lewis acid strength.

The rational evaluation of carbon-based conductive ink performance is critical to both industrial production and applications. Herein, a model to evaluate writing performance of conductive ink by line resistance was proposed by investigating possible relations among different parameters and establishing relevant model to estimate ink writing performance. Bulk conductive inks were prepared and characterized to provide samples for model. To improve the precision of model, the impact of external factors including writing speed and angle was studied. Nonlinear regression and back propagation artificial neural network were employed to estimate line resistance, and cross check validation was conducted to prove robustness and precision of model. Most importantly, the investigation will open up a new path for the exploration of other carbon-based handwritten electronic devices.

In this study, a bipolar visible light responsive photocatalytic fuel cell (PFC) was constructed by loading a Z-scheme g-C3N4/ carbon black/BiOBr and a Ti3C2/ MoS2 Schottky heterojunction on the carbon brush to prepare the photoanode and photocathode, respectively. It greatly improved the electron transfer and achieved efficient degradation of organic pollutants such as antibiotics and dyes simultaneously in two chambers of the PFC system. The Z-scheme g-C3N4/carbon black/BiOBr formed by adding highly conductive carbon black to g-C3N4/BiOBr not only effectively separates the photogenerated carriers, but also simultaneously retains the high reduction of the conduction band of g-C3N4 and the high oxidation of the valence band of BiOBr, improving the photocatalytic performance. The exceptional performance of Ti3C2/ MoS2 Schottky heterojunction originated from the superior electrical conductivity of Ti3C2 MXene, which facilitated the separation of photogenerated electron–hole pairs. Meanwhile, the synergistic effect of the two photoelectrodes further improved the photocatalytic performance of the PFC system, with degradation rates of 90.9% and 99.9% for 50 mg L− 1 tetracycline hydrochloride (TCH) and 50 mg L− 1 rhodamine-B (RhB), respectively, within 180 min. In addition, it was found that the PFC also exhibited excellent pollutant degradation rates under dark conditions (79.7%, TCH and 97.9%, RhB). This novel pollutant degradation system is expected to provide a new idea for efficient degradation of multiple pollutant simultaneously even in the dark.

Graphitic carbon nitride (g-C3N4) has attracted extensive attention in energy storage due to its suitable and tunable bandgap, high chemical/thermal stability, earth abundance and environmental friendliness. However, its conductivity should be improved to work as the electrode materials in supercapacitors. In this report, we have prepared a two-dimensional composite (CN-PANI) based on g-C3N4 and polyaniline (PANI) by in-situ polymerization, which can be efficiently applied as electrode material for supercapacitors. The introduction of PANI can increase the conductivity of the electrode, and the porous structure of g-C3N4 can provide enough channels for the transport of electrolyte ions and improve the electrode stability. As a result, the obtained CN-PANI demonstrates excellent specific capacitance (234.0 F g− 1 at 5 mV/s), good rate performance and high cycling stability (86.2% after 10,000 cycles at 50 mV/s), showing great potential for high-rate supercapacitors.

During nuclear waste vitrification, loss of sodium (Na) and boron (B) occurs, as these elements are highly volatile at high temperatures, which causes fluctuations in composition and consequently affects the properties of the glass products. In this study, we investigated the volatilization behaviors of Na and B from a simulated high-level waste glass as functions of heating temperature and dwelling duration. Based on the data obtained regarding the composition of Na and B and the structure of the glass, a hypothetical model was proposed to explain the volatilization behaviors of Na and B from a structural viewpoint. As the loss of Na and B during vitrification, the crystallization of the glass occurred. Thus, the crystallization behavior of the simulated waste glass upon composition deviation was studied.

Biomass carbon materials with high rate capacity have great potential to boost supercapacitors with cost effective, fast charging– discharging performance and high safety requirements, yet currently suffers from a lack of targeted preparation methods. Here we propose a facile FeCl3 assisted hydrothermal carbonization strategy to prepare ultra-high rate biomass carbon from apple residues (ARs). In the preparation process, ARs were first hydrothermally carbonized into a porous precursor which embedded by Fe species, and then synchronously graphitized and activated to form biocarbon with a large special surface area (2159.3 m2 g− 1) and high degree of graphitization. The material exhibited a considerable specific capacitance of 297.5 F g− 1 at 0.5 A g− 1 and outstanding capacitance retention of 85.7% at 10 A g− 1 in 6 M KOH, and moreover, achieved an energy density of 16.2 Wh kg− 1 with the power density of 350.3 W kg− 1. After 8000 cycles, an initial capacitance of 95.2% was maintained. Our findings provide a new idea for boosting the rate capacity of carbon-based electrode materials.

Heteroepitaxy is a better method of enlarging SCD wafer size than homoepitaxy. In this work, several aspects of the bias process for heteroepitaxial diamond nucleation are studied experimentally. First, with increasing bias time, the diamondnucleation pathway is found to transform from “isolated-crystal nucleation” to “typical domain-nucleation” and back to “isolated-crystal nucleation.” An interdependent relationship between bias voltage and bias time is proposed: the higher the bias voltage, the shorter the bias time. Second, a correlation exists between the threshold bias voltage and reactor-chamber pressure: a higher reactor chamber pressure usually requires a higher threshold bias voltage to realize “typical domain nucleation.” Third, diamond bias-enhanced nucleation and growth is observed at a high CH4 content, where the dynamic equilibrium between amorphous-carbon-layer deposition and atomic-hydrogen etching is broken. Finally, epitaxial nucleation is obtained on a substrate with ∅30 mm in a home-made MPCVD setup.

Poor mechanical properties and bacterial infection are the main problems faced by dental restorative resins in clinical use. In this study, graphene quantum dots (GQDs) grafted with imidazole groups and mesoporous silica (MSN) are co-filled in a dental resin to impart excellent antimicrobial activity and mechanical properties to the dental resin. The higher specific surface area of GQDs and MSN results in an increased contact area with the resin matrix, which enhances the strength of the dental composite resin. The introduction of GQDs significantly improves the antimicrobial activity of the resin. The inhibition efficiency of the composite resin against Streptococcus mutans reached 99.9% with the addition of GQDs at only 0.2 wt.%. When MSN and GQDs are co-filled, MSN interferes with the release of GQDs, thus reducing the antimicrobial activity of the dental resin but improving the cyto-compatibility. By reasonably adjusting the amount of GQDs and MSN, the dental composite resin can exhibit excellent antimicrobial properties, mechanical properties and cyto-compatibility at the same time.

지능형 컴퓨팅의 등장으로 빅데이터를 활용한 패션 브랜드 의미 마이닝과 가치 홍보에 초점을 맞춘 새로운 연구 트렌드가 등장하였다. 본 연구의 목적은 인기 여성복 브랜드 5개를 대상으로 다양한 종류의 의류에 대한 소비자 감성 트렌드를 조사하는 것이다. 유니클로, 에이치스타일, 베로모다, 피스버드, 온리. 이를 위해 총 93,550건의 소비자 평가를 수집하고, 키스멧 감성 분석 엔진을 활용하여 의류 유형별 감성 극성도를 분석하였 다. 그 결과, 브랜드에 따라 감정 극성이 크게 다르다는 것을 알 수 있었으며, HSTYLE 후드티, ONLY 니트웨 어, 피스버드 순면, 유니클로 니트가 각각 소비자들에게 가장 강한 긍정적 감정을 불러일으켰다. 또한 이번 연 구에서는 각 브랜드에서 가장 인기 있는 의류 유형과 착용 효과를 밝혀 패션 기업이 효과적인 마케팅 전략을 수립하고 제품 제공을 강화하는 데 중요한 인사이트를 제공했다. 이러한 연구 결과를 바탕으로 게임 업계에서 는 감성 분석을 적용하여 다양한 게임 브랜드, 장르, 게임 플레이에 대한 플레이어의 감정 반응을 이해하고 게임 프로모션 전략과 제품 디자인 개발에 도움을 줄 수 있다. 전반적으로 이 연구 결과는 디자인 분야에서 빅데이터의 잠재력을 입증하고 업계에서 경쟁 우위를 확보하기 위해 빅데이터를 활용하는 것이 중요하다는 점을 강조할 수 있다.

Coal tar pitch is a product with high carbon content and aromatic compounds. Modified coal tar pitch is a high quality raw material for the preparation of intermediate phase pitch, needle coke, carbon microspheres, et al. In this paper, modified coal tar pitch was used as raw material, nitrogen was used as protective gas, and thermal conversion was carried out at constant temperatures (370, 390, 410, 420 °C). Polarized light microscopy, SEM, elemental analysis, FTIR spectroscopy, Raman spectroscopy and XRD diffraction combined with split-peak fitting were used to characterize the microstructures of the thermal transformation products. The results showed that the Iar and CH3/ CH2 contents of the products increased with the gradual increase of the thermal conversion temperature, and the aromatic content increased. And the higher the temperature at the same heating rate, the more the ideal graphite microcrystal content, and the defective graphite microcrystals are converted into ideal graphite microcrystals during the thermal conversion process. When the reaction temperature exceeds 390 °C, the microstructure of the thermal transformation products is anisotropic spheres, and the small spheres fuse with each other and tend to be basin-like and mosaic structure as the temperature increases.

Transition-metal phosphides (TMPs), a promising anode material for lithium-ion batteries (LIBs), are limited in application because of its serious volume effect in the cycle. In this work, a simple electrospinning strategy was proposed to restrict the grain size of CoP nanocrystals by nano-confined effect of carbon nanofibers with ligands. The addition of ligands not only could realize the uniform dispersion of CoP nanocrystals, but also strengthen the bond between the metals and carbon nanofibers. As a result, the CoP/CNF composite exhibits excellent lithium storage performance, and its reversible specific capacity could reach 1016.4 mAh g− 1 after 200 cycles at a current density of 200 mA g− 1. The research is anticipated to provide a new idea for the preparation of anode materials for lithium ion batteries.

Carbon dots (CDs) with tunable fluorescence emissions have been developed from a wide range of small organic molecules with various bottom-up syntheses. However, most of them were prepared under high temperatures and high pressures with long reaction times and tedious purification processes. In addition, previously reported carbon dots frequently displayed excitation-dependent emissions, which restrict their further applications. Herein, we present a simple and rapid microwaveassisted solvothermal synthesis of multicolour carbon dots with excitation-independent emissions. In ethylene glycol, the green (G)-CDs emitting at 537 nm with a quantum efficiency (QY) of 15% were obtained by using a single precursor of phloroglucinol, and blue (B)- and yellow (Y)-CDs emitting at 436 nm and 557 nm with QYs of 55% and 28% were derived with additives of o- and m-phenylenediamine, respectively. Analyses of their chemical structures and optical processes suggest that highly polymeric carbon dots were uniformly formed from the small molecules and their fluorescences were predominantly originated from rapid direct recombination. Furthermore, emissions at different wavelengths were mainly attributed to different degrees of oxidation (13.9%, 15.2% and 16.4% oxygen in B-, G- and Y-CDs, respectively) and different proportions of pyrrolic nitrogen (10.4% and 1.40% in B- and Y-CDs, respectively). To demonstrate the application feasibility, the obtained carbon dots were utilized for ion detection and anti-counterfeiting. Based on static quenching of the carbon dots’ fluorescence, micro amounts of ferric ion in water samples were detected selectively and reproducibly. Moreover, the anti-counterfeiting pattern constructed by the carbon dots emitted fluorescence under ultraviolet illumination, but concealed perfectly under daylight. This achievement is of great potential for developing multicolour carbon dots of high qualities.

Cracks are an inevitable problem during the use of materials, and flexible sensors with self-healing capability are of great importance for applications in wearable devices and skin-like electronic devices. This paper prepared self-healing flexible strain sensors by compounding self-healing polyurethane with carbon nanotubes. First, by changing the ratio of disulfide bonds, a good balance between mechanical properties and self-healing efficiency was achieved in the prepared self-healing polyurethane. The most balanced sample reached 12.28 MPa in tensile strength, after 24 h of self-repair at 30 °C, the tensile strength was 7.75 MPa, and the self-repair efficiency was 63.11%; after 24 h of self-repair at 80 °C, the tensile strength was 11.64 MPa, and the self-repair efficiency reached 94.79%. Then the sensors prepared by compounding with carbon nanotubes showed a good electrochemical response, and both slow and fast repeated bending of the finger wearing the sensors yielded significantly different electrical signal changes, and the sensors were cut off and still had the same function after self-repair at 30 °C, demonstrating their excellent potential for applications in soft robots, wearable devices, etc.

Doping graphene to epoxy resins can improve the protective ability of the coating, but the lack of active anticorrosion function greatly limits its application in the field of anticorrosion. Herein, N/S-rich few-layer-graphene (N/S-FLG) was prepared and adopted to endow epoxy coating with dual passive/active corrosion protection. The obtained amphiphilic N/S-FLG is highly dispersed in the epoxy coating, giving rise to the enhanced hosting effect for graphene defects, avoiding the interface corrosion and blocking the penetration of corrosive species. Furthermore, the doping of N and S endows graphene sheets favourable catalytic ability for corrosive oxygen, actively eliminating its contribution to metal corrosion. Under this dual effect, the passive and active anticorrosion properties of epoxy coating are simultaneously enhanced. The coating with 1 wt% N/S-FLG reduces the corrosion rate of metal to 6.5 × 10– 5 mm/a, exhibiting almost no corrosion. The proposed concept of introducing nanocatalytic N/S-FLG is facile and eco-friendly, and will undoubtedly promote the practical application of anticorrosion coatings.