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Glucose Sensing Optionally in Optical and Optoelectrical Modes Based on Au-TiO2 Schottky Nanojunctions
Full text linkAbstract: In recent years, metallic nanostructures have been extensively researched in the field of plasmonic for optical and optoelectronic applications such as biochemical sensing. However, an additional optoelectronic converter or spectrometer is usually required for the sensing application. Herein, the orderly-patterned Au-TiO2 Schottky junction with an Al film that we coupled, which simultaneously works as an optical reflector and conducting layer, can achieve optical sensing of glucose by exciting surface plasmon resonance associated with the environment, and meanwhile can realize glucose detection with direct electrical-signal readout by collecting the photogenerated carriers inside the Au nanostructures and TiO2 film. When used in optical mode, the designed sensor shows a sensing sensitivity of up to 1200.0 nmRIU-1 in numerical calculation, and the measured value is 346.1 nmRIU-1. When used in optoelectrical mode, the glucose sensor under one-sun illumination obtains a sensitivity of 70.0 µAM-1cm-2 in the concentration range of 0–10 mM, with a detection limit of 0.05 µM (Signal/Noise=3). Simulation and experimental results demonstrated that the Al-film-coupled Au-TiO2 Schottky nanojunction can monitor glucose concentration optionally in optical and optoelectrical modes, which presents an alternative route to the miniaturized, portable, and multi-functioned sensors
Remarks on Solving Methods of Nonlinear Equations
Full text linkAbstract: In the field of mechanical engineering, many practical problems can be converted into nonlinear problems, such as the meshing problem of mechanical transmission. So the solution of nonlinear equations has important theoretical research and practical application significance. Whether the traditional Newton iteration method or the intelligent optimization algorithm after the popularization of computers, both them have been greatly enriched and developed through the continuous in-depth research of scholars at home and abroad, and a series of improved algorithms have emerged. This paper mainly reviews the research status of solving nonlinear equations from two aspects of traditional iterative method and intelligent optimization algorithm, systematically reviews the research achievements of domestic and foreign scholars, and puts forward prospects for future research directions
CdS Covered with Ga-P Electron Exchange Membrane for Efficient Photocatalytic Hydrogen Prodection
Full text linkAbstract: CdS is one of the best semiconductor photocatalysts. However, photocorrosion will occur when CdS takes part in the photocatalytic system. The general solution is to add sacrificial reagents to inhibit this phenomenon. Even so, it can not maintain the stability of CdS. In order to improve the stability and efficiency of CdS in pure water, Ga-P electron exchange membrane was designed to modify its surface. Under radiation of visible light, a significant increase can be observed in hydrogen production activity. In the absence of Pt as electron transfer agent, the modification of Ga-P realizes decomposition of pure water from zero to one. At the same time, the hydrogen production rate is increased about 5 times with Pt and catalytic life is greatly extended. Through proof of controlled experiment, Ga-P electron exchange membrane can not only prolong the lifetime of photogenerated electrons, but also change the direction of electrons. The formation of a protective membrane makes composite photocatalyst improve the stability and enhance the photocatalytic activity. Based on the analysis of TEM, fluorescence lifetime, UV-Vis diffuse reflection and photocurrent response, the mechanism is analyzed from atomic radius, nuclear orbit and energy level. For homogeneous electronic band structure and XPS analysis, we determined that the binary catalyst formed an S-scheme heterojunction. The work provides a potential way to design a more efficient and stable composite photocatalyst in the future. And contributed to the development of S-scheme heterojunctions
Evaluation of the Failure Probability of a 2D RC Frame Subjected to Column Loss
Full text linkAbstract: This study regards the evaluation of the failure probability of a symmetrical 2D reinforced concrete frame composed of 4 spans and 5 floors, in case of an accidental event which causes the central base column loss. The frame is an internal one of a typical building designed in a highly seismic area, characterised by a high ductility class. The frame is modelled in the non-linear finite elements software Atena 2D, accounting for both geometrical and material non-linearities. The uncertainties relevant to the problem are included by sampling both material and action variables, adopting the Latin Hypercube Sampling technique. To compute the failure probability associated to the accidental scenario, two sets of analyses are considered: the first set to compute the capacity of the structure against the column removal by means of displacement-controlled pushdown analysis; the second set to evaluate the demand in terms of external loads, properly combined within the accidental combination according to the codes. The external load is then amplified in order to include the dynamic effects characterising a scenario of a structural member loss. Finally, the probability of the demand exceeding the capacity is evaluated
Profit-oriented High-speed Railway Network Line Planning with Capacity Limitations
Full text linkAbstract: Line planning is the transportation service\u27s fundamental, which directly affects the subsequent operation plans. It is better to focus on the operational profit when considering the market competition for transportation operation plans. This paper aims to maximize the operational profit when optimizing the high-speed railway network line plan by constructing a mixed integer nonlinear programming model. The model integrates line planning and passenger route choice behaviors. An adaptive simulated annealing algorithm with neighborhood search is applied based on a given line pool. A heuristic passenger assignment method is developed to ensure a high level of passenger satisfaction. The proposed model and algorithm are experimentally evaluated. The instance results show that the operational profit and capacity utilization can be significantly improved. Compared with the designed greedy heuristic algorithm, the proposed algorithm performs better in operational profit improvement and has high efficiency
Opposition-Based Learning Equilibrium Optimizer with Application in Mobile Robot Path Planning
Full text linkAbstract: The objective of mobile robot path planning (MRPP) is to devise the shortest obstacle-free path for autonomous mobile robots based on a given terrain. Numerous MRPP methods have been extensively researched. This paper presents a novel approach called Opposition-based Learning Equilibrium Optimizer (OEO) for generating smooth paths for mobile robots. The fundamental idea behind OEO is to introduce an opposition-based learning mechanism while maintaining the overall framework of the basic EO algorithm. This modification alleviates the susceptibility of the basic EO algorithm to local optima. The OEO algorithm is employed to provide smooth paths for autonomous mobile robots, and the results are compared with several classical metaheuristic algorithms. Comparative analysis across different environments demonstrates that the proposed OEO-based path planning method consistently yields the shortest and most collision-free paths with superior stability
Black Coloured Glazes with Tetragonal CuCr2O4 Ceramic Pigment as Selective Solar Absorbers for Integral Ceramic Solar Collectors
Full text linkAn efficient and low-cost Selective Solar Absorber for integral ceramic solar collectors, based in glazes pigmented with t-CuCr2O4 and Sb modified t-CuCr2O4 pigments, are characterised and evaluated. The basic kinds of industrial glazes (soda lime glass, double firing glaze 1050 ºC and both single firing glazes of 1080 ºC and porcelain glaze of 1190 ºC) have been checked and characterised by CIEL*a*b* colour, UV-Vis-NIR diffuse reflectance spectra, bandgap measurements, SEM-EDS analysis and solar absorbance spectra. The characteristics of the black powders (L*a*b* and diffuse reflectance spectra with a deviation from the carbon black ΔE*=20.3 and 22.3 respectively) are improved in 0.5 wt% addition of pigments in soda lime glass (ΔE*=6.1 and 9.9 respectively) and in 5 wt% glazed in porcelain glaze 1190 °C (ΔE*=12.0 and 18.4 respectively) which can be considered as low-cost selective solar absorbers (SSA) for integral solar absorber collectors
Magneto-Structural Transition and Refrigeration Property in All-D-Metal Heusler Alloys: A Critical Review
Full text linkAbstract: All-d-metal Heusler alloys has attracted much attention due to its unique magnetic properties, martensite transformation behavior and related solid-state refrigeration performance. These unique type alloys are recently discovered in 2015 and have been widely studied; however, systematic reviews on their magneto-structural transition and refrigeration property are rare. In this review, we first summarize the preparation techniques and microstructure of the bulk alloys and ribbons. Then the magnetic transition and martensite transformation behavior are reviewed, focusing on the correlation between magneto-structural transition and refrigeration properties. The effects of element doping, external magnetic and mechanical fields on the martensite transformation and corresponding magnetic entropy change are summarized. We end this review by proposing the further development prospective in the field of all-d-metal Heusler alloys
Fabrication of Free-Standing Porous BaTiO3 Thick Films by Indirect Selective Laser Sintering
Full text linkThe fabrication of free-standing porous thick films of ferroelectric BaTiO3, using a laser-assisted technique, is presented as a novel alternative to conventional methods. This approach adapts Indirect Selective Laser Sintering (ISLS) to create green films in a single laser pass, avoiding the complexities of traditional processes. Using commercial BaTiO3 powder and polyamide 12 as raw materials, laser processing parameters such as scanning laser speed and power were optimized to produce green BaTiO3 thick films with different thicknesses. After laser processing, the films were conventionally sintered and characterized for phase composition, microstructure, porosity, and electrical properties. X-ray diffraction and Raman spectroscopy confirmed the tetragonal BaTiO3 phase, while mercury intrusion porosimetry revealed a bimodal pore distribution. Impedance spectroscopy demonstrated a positive temperature coefficient of resistivity (PTCR) effect, with a peak resistivity near the Curie temperature. The PTCR behavior is hypothesized to arise from better oxygen adsorption due to the porosity and oxygen vacancies generated during sintering by carbon residues from polyamide degradation. The results demonstrate that ISLS is a versatile technique for producing high-quality, free-standing porous ceramic thick films with potential for a wide range of applications
Self-Organization of Surface Structures during Friction Coatings Based on Forsterite
Full text linkIn the work, the patterns of friction and wear of forsterite-based coatings were studied, and their structural-phase composition, conditions of formation and self-regulation of surface structures were determined from the standpoint of the structural-energy theory of friction. Detonation coatings developed on the basis of forsterite are characterized by high anti-friction properties. The conducted studies showed that the most appropriate application of the investigated coatings is to increase the reliability of operation of friction nodes during strengthening and restoration, for example, for moving pairs of control mechanisms, hinges of guide surfaces, cams, sliding supports, pairs with reciprocating movement, bearings, sliding guides, etc. in which the use of traditional lubricants is undesirable. Compounds of complex oxides of magnesium orthosilicate were used as the basis of composite coatings. The structural and phase composition of the coatings, the peculiarities of the formation of complex alloyed secondary structures, taking into account both the properties of the alloying elements and the structures formed by them, were established. The physical mechanism was determined and the main factors determining the level of thermodynamic graphitization were clarified. The studied self-lubricating compositions can be used both for strengthening and for high-quality restoration of worn triboelements by any technological methods using powder materials