Dual Coupling Research Articles

The effect of structural disorder on the hydrogen loading into the graphene/nickel interface

Hybrid materials composed by porous Ni foams coated by graphene appear appealing architectures to be applied in the field of hydrogen storage, where, due to the high surface-to-volume ratio of both components, are expected to be much more performant than their flat counterparts. In order to explore this possibility, in this study we have grown single layer graphene on nickel foams by chemical vapour deposition in ultra-high vacuum and have investigated the interaction with H atoms as a function of the temperature. By using high resolution C1s core level spectroscopy we found that nearly half of the graphene layer interacts with the support almost as strongly as with the flat ordered Ni substrate, whereas the other half is nearly free standing. Such dual electronic and structural coupling drives the hydrogenation of the graphene/foam interface. By using thermal programmed desorption combined with x-ray photoelectron spectroscopy we found that in the weakly interacting graphene regions, even at very low temperatures, H atoms easily intercalate below graphene, and enter in the bulk of the foam, from where they start to desorb around 180 K. This behaviour mimics what happens when dosing H atoms on the bare Ni foam. On the contrary, H intercalation below the strongly interacting graphene regions occurs only for temperatures around and above 200 K. The thermal desorption curves demonstrated that the presence of the graphene layer does not reduce the effectiveness of H loading in the bulk of the foam. On the other hand, it does not even increase significantly the stored amount with respect to the uncoated support, but contributes to stabilizing the stored hydrogen. Although the fundamental aspects of graphene/foam hydrogenation were here investigated in a regime far below the saturation of the bulk absorption, these measurements can be the starting point for further investigations aimed at establishing the ultimate storage capability of these hybrid nanostructured tanks.

Vibration Characteristics of the Dual Electric Propulsion System of Vessels under Electromechanical Coupling Excitation

An electromechanical coupling driving system is a commonly used system for large overloading ships. In this paper, a dual input electromechanical coupling model, including an inverter power supply, three-phase induction motor, fixed-axis gear, and load, is established. The influences of the gear error, inverter, and coupling stiffness on the vibration characteristics of the system are studied, and the influences of each parameter on the vibration characteristics are analyzed. The inverter power supply part considers the constant voltage–frequency ratio control and sinusoidal pulse width modulation, as well as the inverter. The motor part uses the dynamic motor model based on the equivalent circuit. The fixed-axis gear section uses a translation–torsion model with time-varying mesh stiffness and damping. The mechanical part and the motor part are coupled with the load torque of the motor. The results show that the greater the error of the gear, the greater the vibration of the system, and the rotation frequency error is the main factor. Secondly, by comparing the influence of error value and accuracy difference on vibration, we found that when an accuracy difference exists, the dominant factor of system vibration is the accuracy difference. Thirdly, the use of an inverter also increases the vibration of the electromechanical coupling system. Finally, we found that the lower stiffness of the elastic coupling reduced the vibration of the system.

Modified full bridge dual inductive coupling resonant converter for electric vehicle battery charging applications

In this paper, a modified full bridge dual inductive coupling (LCL) resonant converter for electric vehicles (EVs) battery charging applications is proposed. The main objective of the proposed topology is to operate the converter in constant voltage (CV) and constant current (CC) mode during battery charging. The presented topology's uniqueness comprises the following: i) isolated charging and power factor correction (PFC), ii) to achieve zero-voltage switching (ZVS) and zero-current switching (ZCS) for inverter switches, iii) reduction of number of rectifier diodes to reduce the conduction and switching losses, and iv) reducing the magnetizing current. The output voltage dependence of resonant converter is reduced using a PFC converter against the variations of the alternating current (AC) grid input voltage. The variations of the wide range output voltage and load is compensated by a small variation in switching frequency. The proposed topology's detailed operation is simulated using the MATLAB/Simulink tool.

Research on evolutionary game of the transformation of green technological innovation in manufacturing industries under environmental regulation

As the product of the combination of the concept of sustainable development and the transformation of traditional manufacturing industries, green technological innovation will be affected by various factors, such as the willingness of subject of innovation, environmental regulation and so on. How to research the evolution law of the transformation of green technological innovation in manufacturing industries from the perspective of concept-behavior dual logic coupling is the focus of academia. This composition breaks through the traditional limitation of only studying green technological innovation from the perspective of behavior logic, and brings the conceptual logic of the subject into the perspective of research. It designs the mechanism of the transformation of green technological innovation in manufacturing industries driven by internal and external factors, constructs a three-party evolutionary game model of manufacturing-government-consumer, and mobilizes Matlab software to simulate. Thus, the effects of environmental regulations with different intensities on the transformation of green technology innovation in manufacturing industries are revealed, to provide a theoretical basis for environmental regulations to guide it.

Dual co-catalysts activated hematite nanorods with low turn-on potential and enhanced charge collection for efficient solar water oxidation

Hematite (α-Fe2O3) photoanode suffers from significant photocarrier recombination and sluggish water oxidation kinetics for photoelectrochemical water splitting. To address these challenges, this work demonstrates the construction of dual co-catalysts modified Fe2O3 nanorods photoanode by strategically incorporating CoPi and Co(OH) x for photoelectrochemical water oxidation. The Fe2O3/CoPi/Co(OH) x nanorods photoanode exhibits the lowest ever turn-on potential of 0.4 V RHE (versus reversible hydrogen electrode) and a photocurrent density of 0.55 mA cm−2 at 1.23 V RHE, 358% higher than that of pristine Fe2O3 nanorods. The dual co-catalysts modification enhances the light-harvesting efficiency, surface photovoltage and hole transfer kinetics of the hybrid photoanode. The dual co-catalyst coupling also increases the carrier density and significantly reduces the depletion width (1.9 nm), resulting in improved conductivity and favorable band bending, boosting photogenerated hole transfer efficiency for water oxidation.

A Novel 10-Parameter Motor Efficiency Model Based on I-SA and Its Comparative Application of Energy Utilization Efficiency in Different Driving Modes for Electric Tractor

To build a more accurate motor efficiency model with a strong generalization ability in order to evaluate and improve the efficiency characteristics of electric vehicles, this paper researches motor efficiency modeling based on the bench tests of two motor efficiencies with differently rated powers. This paper compares and analyzes three motor efficiency modeling methods and finds that, when the measured values in motor efficiency tests are insufficient, the bilinear interpolation method and radial basis kernel function neural networks have poor generalization abilities in full working conditions, and the precision of polynomial regression is limited. On this basis, this paper proposes a new modeling method combining correlation analysis, polynomial regression, and an improved simulated annealing (I-SA) algorithm. Using the mean and the standard deviation of the mean absolute percentage error of the 5-fold Cross Validation (CV) of 100 random tests as the evaluation indices of the precision of the motor efficiency model, and based on the motor efficiency models with verified precision, this paper makes a comparative analysis on the full vehicle efficiency of electric tractors of three types of drive in five working conditions. Research results show that the proposed novel method has a high modeling precision of motor efficiency; tractors with a dual motor coupling drive system have optimal economic performance.

Wireless Charging of Electric Vehicles Using Dual Spiral Coil Magnetic Resonant Coupling

Abstract: As we get into a new decade in the 21st century, the progress of electric automobiles has been on a significant rise but still flawed with things like range anxiety, limited number of charging stations, high price range etc. But one of the most important flaw is the range anxiety especially in countries like India where we spend half the time stuck in traffic. So, to overcome that we have come up with a project whose technology is still in development and is being tested worldwide. One method to avoid this is by the introduction of Wireless charging into Electric vehicles which is the main focus of this paper.

Deformation Analysis of an Ultra-High Arch Dam under Different Water Level Conditions Based on Optimized Dynamic Panel Clustering

During the operation period, the deformation of an ultra-high arch dam is affected by the large fluctuation of the reservoir water level. Under the dual coupling of the ultra-high dam and the complex water level conditions, the traditional variational analysis method cannot be sufficiently applied to its deformation analysis. The deformation analysis of the ultra-high arch dam, however, is very important in order to judge the dam safety state. To analyze the deformation law of different parts of an ultra-high arch dam, the panel data clustering theory is used to construct a Spatio-temporal characteristic model of dam deformation. In order to solve the difficult problem of the fluctuating displacement of dam deformation with water level effect, three displacement component indexes (absolute quantity, growing, and fluctuation) are proposed to characterize dam deformation. To further optimize the panel clustering deformation model, the objective weight coefficient of clustering comprehensive distance is calculated based on the CRITIC (CRiteria Importance Through Inter-criteria Correlation) method. The zoning rules of the ultra-high arch dam are established by using the idea of the CSP (Constraint Satisfaction Problem) index, and the complex water level of the reservoir is simulated in the whole process. Finally, the dynamic cluster analysis of dam deformation is realized. Through a case study, three typical working conditions including the rapid rise and fall of water level and the normal operation are calculated, and the deformation laws of different deformation zones are analyzed. The results show that the model can reasonably describe the deformation law of an ultra-high arch dam under different water levels, conveniently and intuitively select representative measuring points and key monitoring parts, effectively reducing the analysis workload of lots of measuring points, and improve the reliability of arch dam deformation analysis.

Dual Space Coupling Model Guided Overlap-Free Scatterplot.

The overdraw problem of scatterplots seriously interferes with the visual tasks. Existing methods, such as data sampling, node dispersion, subspace mapping, and visual abstraction, cannot guarantee the correspondence and consistency between the data points that reflect the intrinsic original data distribution and the corresponding visual units that reveal the presented data distribution, thus failing to obtain an overlap-free scatterplot with unbiased and lossless data distribution. A dual space coupling model is proposed in this paper to represent the complex bilateral relationship between data space and visual space theoretically and analytically. Under the guidance of the model, an overlap-free scatterplot method is developed through integration of the following: a geometry-based data transformation algorithm, namely DistributionTranscriptor; an efficient spatial mutual exclusion guided view transformation algorithm, namely PolarPacking; an overlap-free oriented visual encoding configuration model and a radius adjustment tool, namely frdraw. Our method can ensure complete and accurate information transfer between the two spaces, maintaining consistency between the newly created scatterplot and the original data distribution on global and local features. Quantitative evaluation proves our remarkable progress on computational efficiency compared with the state-of-the-art methods. Three applications involving pattern enhancement, interaction improvement, and overdraw mitigation of trajectory visualization demonstrate the broad prospects of our method.

Research on power transmission optimisation of dual motor coupling drive for pure electric car based on genetic algorithm

Based on a pure electric vehicle, we have adopted a new dual motor coupling drive system to realise a smooth switch between the single motor and dual motor modes, without experiencing power interruption, and a switch between dual motor and single motor modes without experiencing power interruption and with minimum impact. Also, the structural characteristics and working mode are analysed, and the parameter matching and control strategy of the new power system are studied. Taking the 100 km power consumption as the optimisation goal, a non-dominated sequencing genetic algorithm (NSGAII) with elite strategy is adopted to optimise the coupling drive system. The results of the experiment show that the control strategy of the dual motor multimode drive system improves the vehicle economy by 12%.

Design and analysis of the dual motor coupling drive system for electric vehicle

Design and analysis of the dual motor coupling drive system for electric vehicle

Design and analysis of the dual motor coupling drive system for electric vehicle

Design and analysis of the dual motor coupling drive system for electric vehicle

Research on power transmission optimisation of dual motor coupling drive for pure electric car based on genetic algorithm

Research on power transmission optimisation of dual motor coupling drive for pure electric car based on genetic algorithm

Low‐profile wideband dual‐polarized microstrip antenna element for 5G communication

AbstractA low‐profile wideband dual‐polarized microstrip antenna is presented for 5G communication. Using a periodical diamond structure, both low profile and wideband performance have been achieved with high port isolation. Relative bandwidths of 53.4% and 54.0% are obtained for two polarizations with a low profile of 0.047λ0, where λ0 is the free space wavelength at the center frequency of 4.18 GHz. The dual aperture coupling method is adopted for each polarization direction and high‐order modes are stimulated across the passband. The measured port isolation of more than 30 dB is obtained. Unidirectional radiation patterns have been achieved with low cross‐polarization levels. The proposed dual‐polarized microstrip antenna can offer a low‐profile structure and wideband performance, which can be another potential candidate for the 5G communication.

Durability Model of Exposed Concrete On-Site Based on Dual Coupling Factors

Aiming at the problem that the reliability analysis of the outdoor exposed concrete structure under the action of a single factor is not consistent with the actual service environment, a reliability analysis based on the Copula function describing multiple degradation factors is proposed. According to the actual data collected on-site, the relative quality evaluation parameters (RQEP) and relative dynamic elastic modulus evaluation parameters (RDEMEP) was selected as the key degradation indicators, and the Aperture Information Criterion (AIC) was used to determine the optimal marginal distribution function in different degradation trajectories, and obtain the most optimal edge distribution function under a single factor. Optimize the edge distributions reliability curve, establish the relationship between the edge distributions through the Copula function, and couple the edge distributions of the remaining life of the concrete to obtain the joint reliability function of the concrete under the action of the coupling factors. The results show that the selection of two degradation indicators, RQEP and RDEMEP, is helpful in establishing the concrete life prediction model in the field exposure environment, and the RDEMEP are more sensitive to the field exposure environment than the RQEP The Gumbel Copula distribution function can reasonably predict the reliability of exposed concrete on-site under dual coupling factors. The service life of C40 and C50 exposed concrete on site is about 400 and 550 months, respectively.

Modeling and dynamic characteristic analysis of dual rotor-casing coupling system with rubbing fault

With the rapid development of aero-engine manufacturing technology, the dual-rotor system has been employed in part of turbofan engine in order to improve the working performance of aircraft more efficiently. In this study, taking the counter-rotation dual-rotor as the research object, the dynamic model of dual rotor-casing coupling system is established by the aid of MATLAB. The dynamic frequency curves are in good agreement with the results in references and calculated by FEM method, that shows the validity and feasibility of the model. The local rub-impact dynamic model of dual rotor-casing coupling system is established, and rubbing analysis is carried out using Newmark- β method. The effects of rotating speed and speed ratio on local rub-impact response are deeply discussed. The results show that with the increase of rotating speed, combined frequencies and frequency multiplication components are more significant. In addition, speed ratio has a great influence on the periodic motion of the system. With the increase of the absolute value of the speed ratio, the whirl radius of the outer rotor and the normal rubbing force increase dramatically.

Fluorescence Enhancement via Dual Coupling of Dye Molecules with Silver Nanostructures

We demonstrate the enhancement of fluorescence emitted from dye molecules coupled with two surface plasmons, i.e., silver nanoparticles (AgNPs)-induced localized surface plasmons (LSP) and thin silver (Ag) film supported surface plasmons. Excitation light is illuminated to a SiO2 layer that contains both rhodamine 110 molecules and AgNPs. AgNPs enhances excitation rates of dye molecules in their close proximity due to LSP-induced enhancement of local electromagnetic fields at dye excitation wavelengths. Moreover, the SiO2 layer on one surface of which a 50 nm-thick Ag film is coated for metal cladding (air on the other surface), acts as a waveguide core at the dye emission wavelengths. The Ag film induces the surface plasmons which couple with the waveguide modes, resulting in a waveguide-modulated version of surface plasmon coupled emission (SPCE) for different SiO2 thicknesses in a reverse Kretschmann configuration. We find that varying the SiO2 thickness modulates the fluorescent signal of SPCE, its modulation behavior being in agreement with the theoretical simulation of thickness dependent properties of the coupled plasmon waveguide resonance. This enables optimization engineering of the waveguide structure for enhancement of fluorescent signals. The combination of LSP enhanced dye excitation and the waveguide-modulated version of SPCE may offer chances of enhancing fluorescent signals for a highly sensitive fluorescent assay of biomedical and chemical substances.

A new quasi-3-D model with a dual iterative coupling scheme for simulating unsaturated-saturated water flow and solute transport at a regional scale

Soil water in an unsaturated zone is the major source of groundwater recharge, and likewise soil contaminants are the major source of groundwater contamination. It is thus essential to jointly consider soil water movement and solute transport together with groundwater movement and solute transport, which is particularly important when addressing regional-scale problems. This study developed a new quasi-3-D model for simulating regional-scale saturated–unsaturated water movement and solute transport in arid and semi-arid agricultural areas. The unsaturated soil water movement and solute transport processes are simulated by a 1-D soil water and solute transport model referred to as UBMOD, and the saturated groundwater movement and solute transport are simulated by MODFLOW and MT3DMS. In the quasi-3-D model, the soil water movement and groundwater movement modules are iteratively coupled and the soil solute transport and groundwater solute transport modules are iteratively couple. This is referred to as a dual iterative coupling scheme. Strength and weakness of the quasi-3-D model and the coupling scheme were evaluated with two synthetic cases and a real-world application. Results indicate satisfactory performance of the model, which demonstrates the reliability of the dual iterative coupling scheme. Besides, the impacts of spatial and temporal discretization and stress period on model stability and accuracy has been evaluated. And the model is more computationally efficient than the fully numerical methods based on Richards’ equation when the problem is a 2D/3D problem with a scale larger than 10 m. Moreover, the application to the Hetao Irrigation District indicates that the developed model is effective and efficient for the real-world regional-scale agricultural problems. Above all, it is concluded that the new model is more suitable than existing models for simulating regional-scale unsaturated–saturated soil water movement and solute transport in arid and semi-arid agricultural areas.

Mechanistic Insights into the Dual Directing Group-Mediated C-H Functionalization/Annulation via a Hydroxyl Group-Assisted MIII-MV-MIII Pathway.

The experimental investigations on the catalyst [Cp*Rh(OAc)2 and Cp*Ir (OAc)2)]-controlled [3 + 2] and [4 + 2] annulations of oximes with propargyl alcohols have been finished in our previous work and a supposed dual directing group-mediated reaction pathway has been deduced for the chemodivergent product synthesis. However, the detailed interaction modes of the dual directing groups binding with the corresponding metal center to achieve the above observed chemoselectivity remain unclear and even contradict. For instance, the calculational traditional dual direct coupling transition states suggested that both Cp*Rh(OAc)2- and Cp*Ir(OAc)2-catalyzed reactions would generate five-membered indenamines as the dominant products via [3 + 2] annulation. To address this concern, herein, systematic DFT calculations combined with proof-of-concept experiments have been carried out. Accordingly, a novel and more favorable MIII-MV-MIII reaction mechanism, which involves an unprecedented HOAc together with a hydroxyl group-assisted reaction pathway in which the hydroxyl group acts as double effectors for the formation of M–O coordination and [MeO···H···O(CCH3)O···H···O] bonding interactions, was deduced. Taken together, the present results would provide a rational basis for future development of the dual directing group-mediated C–H activation reactions.

Photoinduced copper-catalyzed dual decarboxylative coupling of α,β-unsaturated carboxylic acids with redox-active esters

The first photoinduced copper-catalyzed dual decarboxylative cross-coupling of α,β-unsaturated carboxylic acids and redox-active esters has been developed. This reaction enabled C(sp2)–C(sp3) bond formation, which afforded a variety of synthetically valuable alkene derivatives. Many α,β-unsaturated carboxylic acids and redox-active ester derivatives were tolerant to this reaction. The reaction also tolerated many common functional groups.