bluuebunny/crossref_metadata_2025 huggingface dataset:
Majorana-like end states in one-dimensional dimerized Kitaev topolectrical circuit
Authors: Yao Junjie , Hao Xiamin , Song Biyu , Jia Yizhen , Hua Chenqiang , Zhou Miao
Published: March 2022

Majorana zero modes (MZMs) have attracted tremendous attention in condensed matter and materials physics communities due to the implications in topological quantum computation. One-dimensional (1D) dimerized Kitaev chain is a prototype model for MZMs, but its realization remains a challenge in material systems. Here, we develop a distinctive approach to achieve Majorana-like end states (MESs) by implementing practical dimerized Kitaev topolectrical circuits. Specifically, two arrays of inductors are arranged to simulate particles and antiparticles, while intra- and inter-array capacitive connections are used to model hopping and superconducting pairing. Three topological phases can be achieved by tuning the capacitance, i.e. the trivial phase, Su–Schrieffer–Heeger topological phase and Kitaev phase, with distinct field strength distributions in real space. Majorana splitting is observed around a domain wall in the circuit, and we propose an efficient experimental observable-edge distance-to characterize the process as premonition of topological phase transition. Remarkably, dynamics of the Gaussian wave packet in time domain provide an excellent signal to detect MESs in experiments, as only MESs allow nonlocal propagation in circuit network. Our results not only manifest the superiorities of topolectrical circuits for exotic topological states, but also pave the way for possible applications in electrical engineering and signal processing.
Entropy production and lumping of species can effectively reduce complex cell signaling pathways
Authors: Khoshnaw Sarbaz H A , Rasool Hemn M
Published: March 2022

A complicated issue in many cell signaling pathways is mainly related to the number of state variables and parameters. This is computationally very expensive, it may sometimes difficult to predict their model dynamics. Such problems in cell signaling pathways can be simplified and analyzed easily based on model reduction approaches. In this work, we suggest a model reduction technique based on entropy production analysis and lumping of isolated species. The proposed approach provides an improvement in the field of cell signaling pathways. We apply this technique to minimize the number of reactions and elements for the elongation factors EF–Tu and EF–Ts pathways. Computational simulations are computed for the given initial values and parameters. The results provide accuracy and important agreement between the original and reduced models. More interestingly, the model approaches here may apply to a variety of complex cell signaling networks and may use for theoretical and practical purposes.
Crowdsourcing in Megascience projects in Russia: current state and prospects
Authors: Vorontsov D I
Published: March 2022

Within the framework of this article, the potential application of crowdsourcing mechanisms for the development of Megascience-class projects in Russia and the issues that arise in this regards are considered. Examples of the use of crowdsourcing mechanisms in current projects of this class are given. Proposals for their possible use in the future are made. The work raises the question of the branches of law, with the help of which it will be possible to regulate crowdsourcing in Russia.
A Image Segmentation Method Based on Dual Convolutions
Authors: Dong Xiaoyu , Hu Xichuan
Published: March 2022

Fundus retinal vascular image has high medical diagnostic value. Its segmentation image can help assess diseases that cause retinopathy, such as cerebral small vessel disease, coronary artery disease, glaucoma, and diabetes. Classical encoder-decoder segmentation methods like Unet cannot extract subtle details as well in the retinal vessel due to its complex structure. In this paper, we propose an improved Unet algorithm based on dual convolutions and integrate MultiRes feature extraction module. The MultiRes module improves the feature learning ability of micro vessels, which can collect further subtle details. The dual convolutions module utilizes dual feature maps with varying scales and channels, exchanges feature information with each other, thus can capture retinal vasculatures with better performance. Experiment based on the DRIVE dataset indicates that the accuracy, sensitivity, specificity, AUC(area under curve), and Dice coefficient of the proposed model are 96.13%, 78.57%, 98.17%, 97.29% and 80.87%. Compared with the existing advanced algorithms, our proposed algorithm shows its effectiveness.
Influence of Mesh Density on Repeatability of FSW Process Simulation Based on DEFORM
Authors: Lu Xiaohong , Qiao Jinhui , Luan Yihan , Han Zesheng , Liang Steven Y.
Published: March 2022

To solve the problem of the relative error caused by mesh density is difficult to quantitatively evaluate, a process simulation model of FSW (friction stir welding) 2219 aluminum alloy is built based on DEFORM. Process simulation models with different mesh densities are solved, the influence of mesh density on simulation repeatability and time-consuming is analyzed, and the mesh density suitable for the process simulation model is determined. The evaluation method proposed offers a theoretical reference for the determination of local optimal mesh density of the FSW process simulation model based on DEFORM. This study provides a basis for high precision prediction and characterization of the temperature distribution of FSW on heavy-lift launch vehicle fuel tank.
Accurate Measurement of DC Electric Energy in Power Plant
Authors: Gong Dan , Zhang Chuang , Ma Jian , Zhang Congyu , Liu Xinyu , Guo Shuai
Published: March 2022

With the development of electric vehicles, the corresponding charging facilities are gradually accelerating the construction. Aiming at the corresponding problems existing in the domestic electric vehicle charging facilities, such as management and control, operation and maintenance and testing, this paper studies the integrated test system for AC / DC charging facilities, and introduces the design concept, hardware scheme, software scheme and processor platform of the system in detail. The system is based on GB/T18487.1-2015, NB/T33008-2018 and other test standards, and can be used for type experiments and performance tests of charging piles. The research results in this paper are conducive to the development of charging inspection facilities in the direction of integration, digitization, and automation. It is of great significance for charging facilities to reduce operation and maintenance costs and improve charging service level. It is conducive to promoting and ensuring the sustainable development of the domestic electric vehicle industry and the needs of implementing China’s long-term development plan and energy conservation and emission reduction policies.
Face Dataset Augmentation with Generative Adversarial Network
Authors: Cong Kelun , Zhou Mian
Published: March 2022

Face recognition is a widely used scene of artificial intelligence technology. However, some face occlusions cause the face to be unable to be effectively detected in a specific environment. Although many algorithms have been proposed to solve this problem, in essence, a large number of face image data containing occlusion elements is needed to train to improve the detection ability of the algorithm. In recent years, this problem can be effectively solved by using the image generation ability of generative adversarial network. This paper proposes an improved Generative Adversarial Networks (GAN), which improves the effect of occluded face image generation by adding coding module. Through the expansion of data set, the detection accuracy of several classic face detection models for occluded faces is improved by more than 3%. At the moment when the epidemic has not been over, occlusion face data is of great significance to improve the performance of face detection systems in specific public places such as customs security inspection and medical centers.
Classification Prediction Model Based on BP Neural Network
Authors: Jiang Da , Liu Changhua , Ou Zuhao
Published: March 2022

In this paper, a method of plant image processing combined with BP neural network was proposed to predict the disease degree of brassica napus. First, the initial image preprocessing, the roots of brassica napus. were used by Otsu threshold segmentation algorithm is combined with morphological open operation, segment the rape root image with better effect, in order to reduce image size inconsistent on the effects of extracting feature parameters, can be reconstructed images after segmentation, and then obtain the root image multiple characteristic parameters, Through chart correlation analysis to select the feature parameter information, with the characteristics of the rape root disease was positively associated with the degree of disease information to refactor pixel area and the longest diameter, finally establish the BP neural network, two characteristic parameters extracted as input, root disease degree level as the output, training network and prediction and comparison. The experimental results showed that the mean square error of the classification network for brassica olerica was 0.049, and the accuracy rate of the classification results predicted by the model was about 93%. The prediction effect was good and feasible.
The Influence of Control Parameters on Precision of Welding Seam Tracking in Manually Control Master-slave Robot Remote Welding System
Authors: Chen Hongtang , Ma Haijun , Jiang Hongli , Lv Shenjin , Li Yong , Liu Heshan
Published: March 2022

The welding seam tracking precision is one of the key factors to ensure welding qua ntity. However, when the operator manually manipulate the master robot to control the slave ro bot tracking welding seam used the master- slave robot remote welding system, seam tracking precision does not meet the requirement of the welding quantity, the influence of control param eters on precision of welding seam tracking is unkown. In this article, a master-slave robot rem ote welding system is set up which includes a master robot with 6 degrees of freedom, a compu ter control system, and robot HP3J carrying a welding torch and laser sensor system. The slave robot tracking welding seam was controlled by computer control system and the human operat or via master manipulator. The influence of control parameters (cross deviation, arc length and welding speed) on precision of welding seam tracking was analysed. The experiment results de monstrate the more control parameters of operator, the lower tracking precision, so in order to guarantee a good welding seam tracking effect, the operator should control less parameters.
A New Optimization Method for Pole-arc Parameters of Variable-gap Two-phase Switched Reluctance Motor
Authors: Wang Ruihao , Huo Junling , Pan Xiaowei , Wang Qihui , Wu Hongxing
Published: March 2022

As a switched reluctance motor with simple structure, a two-phase switched reluctance motor (SRM) has the advantages of the above. In contrast, the complexity of the motor structure and the manufacturing cost are low, and only one-way operation is required. The control strategy is simple. Based on the analysis of the self-starting mechanism of the two-phase switched reluctance motor with variable air-gap rotor structure, the structure scheme of the variable airgap rotor is determined by the finite element method. Two-dimensional model of two-phase switched reluctance motor with vertical air gap structure. To minimize the electromagnetic torque ripple, the structure parameters of the motor such as air gap, stator-rotor pole arc and winding turns are optimized. To solve the finite element optimization simulation time process, a numerical batch interpolation method is developed to optimize the non-uniform pole arc of the rotor to improve the finite element simulation speed. Finally, the fixed-rotor pole arc and winding turns of the motor are optimized. The motor parameters are further optimized to make the static performance of the motor more stable.
Sliding Mode Control of Permanent Magnet Synchronous Motor Based on Disturbance Observer
Authors: Song Zehang , Sha Linlin , Yao Xiaodong
Published: March 2022

A sliding mode control method of surface mount permannent magnet synchronous motor (SPMSM) based on disturbance observer was proposed to solve the problem of internal parameter disturbance caused by temperature change during PMSM operation. Firstly, a disturbance observer based on parametric disturbance is established. Secondly, a new double power approach law is used to design the speed ring controller, and the stability of the controller and observer is proved by Lyapunov stability theory. The results turns out that the new method can clearly improve the performance of the motor, weaken chattering, enhance the robustness and anti-interference ability.
Selecting Sensitive Features Using CDET for Bearing Fault Diagnosis
Authors: Se Haifeng , Zhou Lei , Xu Shiming , Kai Song
Published: March 2022

The rolling bearing fault detection technology solution can be used to maintain the machinery in advance and avoid downtime and safety accidents. However, the current studies primarily focus on utilizing complex algorithms to improve the accuracy of fault diagnosis, while neglecting the influence of extracted features on diagnosis results, resulting in redundancy and conflict among features. To address such an issue, a feature selection method based on compensation distance evaluation technique (CDET) is proposed to optimize the feature set extracted from acoustic emission (AE) signals. Firstly, multiple failure data of the bearing are modeled by the fault simulation experiment platform. Then, the proposed feature selection method is used to evaluate the sensitive features. Finally, hidden markov modelsupport vector machine (HMM-SVM) series model is used to predict works. The experimental results show that the proposed method selects 7 sensitive features from the feature set composed of 13 features and achieve a high accuracy (99.3%).
Vibration Analysis on the Rack of Electric Mini-tiller
Authors: Huang Guojun , Wang Hongrong , Liang Xincheng
Published: March 2022

The conventional internal combustion mini-tiller is a vitally agricultural tool with multiple functions, meanwhile the strong vibration may impose damaging effect on the user’s health. Hence, it is inevitable to replace the internal combustion by the electric motor. Although the performance of the electric mini-tiller has been enhanced greatly, the remaining vibration is still distinct and some diseases can be occurred incontrovertibly. The rack is one of the most significant components to connect the different parts for the electric mini-tiller, and the index may be improved through redesigning the structure of rack. In this study the rack has been analysed under different structure by Ansys workbench software, and simulations show that the vibration acceleration from the rack to the human body decreases greatly after the structure had been redesigned, which signifies the handling stability and riding comfort of mini-tiller can be promoted without the extra cost. Although the total vibration acceleration is reduced a lot, the vibration of cutting roller is more distinct than that of before. Therefore, the cutting configuration is needed to be optimized, and vibration transmitting path of cutting roller should be intervened as well in the future, enhancing the handling comfort and energy conservation of electric mini-tiller.
Rolling Bearing Fault Diagnosis Based on PCA-ResNet
Authors: Peng Xinjie , Wang Zhigang , Li Binbin , Qian Long , Jiao Bin
Published: March 2022

Aiming at the situation that there are many interference factors in the collected signals of rolling bearings working in harsh and complex environment. Propose A method of noise reduction based on principal component analysis (PCA) and fault diagnosis and classification based on residual neural network (ResNet). Experimental results show that this method can effectively complete the task of fault identification and classification, and is superior to LeNet-5, SVM, DNN and other common deep learning methods.
Research and Application of Display System of Component-Based Virtual Instrument for Land and Air Platforms
Authors: Cai Hao , Mao Zheng
Published: March 2022

With the diversified combat missions in the new era and the development of industrialization, the demand for military and civilian equipment continues to increase, and the development and upgrade standards of land-air dual-use platforms must also move toward standardization. As the core of information visualization and control standardization, the component-based virtual instrument display platform is an important part of the integrated information display system of the land-air platform. The component display platform takes the optimization of the research and development, design and maintenance of the land and air mobile platform as the starting point, and at the same time meets the needs of wartime and meets the development trend of future informatization. It adopts engineering design ideas, hierarchical software layout and componentized ideas of man-machines. The concepts of interaction design are based on componentization techniques, serial communication, data dictionaries, pattern transformations, etc. A comprehensive information display platform aims to increase software productivity, reduce development costs and degree of coupling, and meet human-computer interaction as well as user-friendliness requirements.
Study on the Division Method of Pipeline Robot Module
Authors: Zhu Haizhen , Yuan Yan , Lei Yongjun , Li Xiaoru
Published: March 2022

The working environment in the pipeline is getting worse, and there are more and more functional needs for the pipeline robots. The traditional pipeline robot structure is fixed and single, and the rapid design and assembly cannot be realized. There are still problems of repeated design between different types of robots.In view of these problems, a top-down modular design method—combining of axiom design and IDEF(ICAM DEFinition method) functional modeling is proposed to divide the pipeline robot system architecture.This method uses the mapping relationship between function and structure, and extracts the general modules and special modules in different types of pipeline robot systems, which realizes the modular design of the non-modular pipeline robot, so that the module structure at its component level can be universally exchanged to form resource sharing.
Modeling, simulation and experimental study of squeeze engine system
Authors: Dong Libao , Nie Wansheng , Li Geng
Published: March 2022

Taking the squeeze engine system as the research object, its dynamic characteristics are simulated and experimentally studied. Based on the idea of modular modeling, the dynamic model of engine components is established, and the system simulation model is constructed combined with the engine test system. The whole working condition dynamic simulation of extrusion engine is studied, and the actual ignition test is carried out to verify the whole working condition dynamic simulation of engine. The simulation and test results show that the dynamic simulation results of the engine under all working conditions are in good agreement with the test data, which verifies the accuracy of the simulation model.
Finite Time Convergent Cooperative Guidance Law for Multiple Flight Vehicles Considering Detection Efficiency
Authors: Deng Junzhi , Zhang Xi , Li Wei , Xia Qunli , Zhou Hang
Published: March 2022

Aiming at the problem of cooperative interception of maneuvering target, a cooperative guidance of multiple flight vehicles considering detection efficiency was designed based on the multi-agent finite time consensus theory. Considering the first-order dynamic of the flight vehicle, the guidance law was designed according to the relative motion equations and the model of cooperative detection, which can improve the estimation accuracy of the relative distance using the terminal LOS (Line-of-sight) angle and guarantee simultaneously strike the target in a finite time. Numerical simulation results show that in the case of different maneuvers of an evader, each flight vehicle can hit the target at the same time with a designed terminal LOS angle, and the detection accuracy of the relative distance was continuously improved during the terminal guidance.
PSO algorithm tuning PI_ PID controller parameters of quad-rotor UAV
Authors: Jing XueDong , Wang XuFei
Published: March 2022

Aiming at the difficulty in tuning the parameters of the quad-rotor UAV PID controller, the paper uses the PSO (Particle swarm optimization) algorithm to intelligently optimize the PID controller parameters of the quad-rotor UAV. The paper proposes to set the fitness function of the PID controller’s PSO algorithm with the controller’s adjustment time and overshoot. The PSO algorithm is a kind of bionic algorithm that birds are not. It can iterate through a huge number of particles and after a specified number of iterations, and finally find the method of the global optimal solution. In this paper, the attitude control of the pitch direction of the quad-rotor UAV is tested. In order to meet the control accuracy of the quad-rotor, the PI_PID controller is used as the attitude control of the pitch in the experimental part. The PSO algorithm can be used to quickly tune the parameters of the quad-rotor UAV PID controller. The PID controller tuned by the PSO algorithm has a shorter adjustment time and lower overshoot. It can make the attitude of the quad-rotor, have better control effect.
Research on prediction method of hydro-resistance of a seaplane based on BP network
Authors: Gao Xianjiao , Liu Tao , Zuo Zibin , Wu Bin
Published: March 2022

As one of the important hydrodynamic indexes of seaplane, resistance performance is related to the practicality and economy of a seaplane. Due to the strong nonlinearity between resistance and test variables, it is difficult to predict the response relationship between them by conventional data fitting method. This paper proposes to use BP neural network to construct the response relationship between model parameters and hydro-resistance, and so it can be used to the prediction of aircraft resistance under different conditions. The result shows that prediction error of this method is controlled within 4.4%, which meets the needs of engineering accuracy. This method can reduce the model test cost to some extent, and provide a new way for the prediction of hydro-resistance of seaplane.
Discussion on research status and key technologies of morphing aircraft
Authors: Guo Jiabao , Zhao Changjian , Song Zhiguo
Published: March 2022

Morphing aircraft is not only a hot point of the aeronautics and aerospace research, but also one of the most potential development directions in the future. However, the key scientific problems unsolved and bottlenecks are still limiting the development of morphing aircraft. This paper will start with the development and research status of morphing aircraft and focus on the key technologies to be solved in related fields. Finally, the future development of morphing aircraft technology is prospected.
Preparation of CuI films by continuous ion layer adsorption reaction (SILAR)
Authors: Zhao Jin , Chen Shuai , Liang Jiawen , Li Wei , Yan Zhanlin , Zhang Bin , Chen Naichao
Published: March 2022

Transparent conductive CuI films were prepared on ITO glass substrates using a low-temperature liquid-phase film preparation process, the continuous ion layer adsorption reaction (SILAR) method. The influence of process parameters on the film quality and film surface morphology was investigated, and the relationship between the growth rate of the films and the concentration of the reaction solution as well as the number of cycles was studied and analyzed. The experimental conditions for the preparation of CuI films with the highest transmittance were as follows: the concentration of the anion driving solution was 0.075 mol/L. The film thickness of the CuI films increased with the number of cycles, and films with a thickness of 1.73μm could be produced in 40 cycles. The films were tested by XRD and SEM and showed high purity, flat and dense surface.
Study on radar scattering characteristics of double S-shaped nozzles with different aspect ratio
Authors: Gao Xiang , Shi Yongqiang , Li Yiwen
Published: March 2022

To study the radar scattering characteristics of dual S-bend nozzles with different exit aspect ratios, the iterative physical optic method (IPO) method and equivalent edge currents method (EEC) method were combined to build a code that can be used to solve the electromagnetic scattering field of the nozzle. The reliability of the method has been verified by comparing the reference data. Then, the forward and back-forward IPO and ray tracing methods are used to reduce the calculation time. CFD method is used to calculate and analyse the influence of aspect ratio double S-shaped nozzle on aerodynamic performance. The thrust coefficient and the total pressure recovery coefficient of the double S-shaped nozzle will gradually decrease with the increase of the aspect ratio. the influence of the aspect ratio on the radar scattering characteristics of the dual S-shaped nozzle under the C-band was simulated by the IPO and the results were discussed.it is obtained that the RCS average value in the range of −40°~40° gradually decreases with the increase of the aspect ratio. Under the vertical polarization mode of the pitch detection plane, the average RCS of the AR6 model is 52.8% lower than that of the AR3 model, while it is reduced by 11.0% in the horizontal polarization mode, which has better stealth performance.
Satellite Orbit Design and Analysis Based on STK
Authors: Zhang Shilin
Published: March 2022

The design and analysis of satellite orbits has always been a hot topic in the aerospace field. Through the selection and optimization of orbital parameters, the satellite can meet the corresponding performance indicators and work requirements. However, there are often various constraints in actual scenes, so the orbital parameters cannot be set arbitrarily. Therefore, how to design the orbit under the constraints to make the satellite in optimum condition is very important. Based on STK, this paper proposes a satellite orbit design method, and realizes the optimization of the orbit through the simulated annealing algorithm. The simulation results show that this method can achieve satisfactory results and has certain practical value.
Analysis of Turbulent Boundary Layer Jet Flow Pattern of TPS Standard Nozzle
Authors: Mu Guozhen , Lyu Qiongying
Published: March 2022

The design of the standard nozzle affects the air mass flow calibration accuracy of TPS. The relationship between the outlet diameter and the jet flow pattern is studied by performing jet simulation simulation on the three outlet size standard nozzles under the same boundary conditions. Through the simulation results, it can be seen that the outlet diameter under a single variable determines the value and range of the jet Mach number, which will cause a huge change in the mixing zone of the turbulent boundary layer, which directly affects the turbulent kinetic energy and has a linear relationship with the mass flow rate.
Study on Variable Geometry Scheme of High Mach Axisymmetric Inlet
Authors: Li Jian , An Yang , Zhang Kunyuan
Published: March 2022

For scramjet, the inlet plays the role of capturing airflow, pressurizing and decelerating the airflow, and providing supersonic airflow to meet the combustion requirements for the downstream combustion chamber. In this paper, a prototype inlet is designed by using the method of spiral characteristic lines, and then the influence of moving center cone on the inlet performance is studied by numerical simulation. It can be found that the method of moving the center cone can obviously improve the performance of non-design point and self-starting performance of the inlet.
Research on switching method of low inertia microgrid parallel transformer
Authors: Ding Wenhui , Huang Qiyue
Published: March 2022

The vigorous development of clean energy technology has gradually led to the formation of a new power system. The new power system takes clean energy as the main supply, and has the advantages of clean, low-carbon, flexible and efficient. However, it has low inertia and is easily affected by energy fluctuation, resulting in protection misoperation. Microgrid has small volume and poor anti-interference ability. The magnetizing inrush current generated by parallel transformer during switching is very easy to lead to misoperation of transformer protection, which threatens the stability and safety of the whole power grid. Therefore, are switching method of parallel transformer is proposed. First, close all secondary circuit breakers, and then select the primary circuit breaker of one transformer for initial closing. After the closing is completed, conduct the closing operation again after the delay and phase angle determination. The two switching operations are completed, and the no-load closing operation is completed. Finally, the PSCAD simulation model is established to simulate the AC microgrid to verify the feasibility of this method.
Analysis of UAV patrol inspection technology suitable for distribution lines
Authors: Wan Dai , Zhao Miao , Zhou Hengyi , Qi Fei , Chen Xin , Liang Guanxuan
Published: March 2022

With the continuous improvement of UAV manufacturing level, it is more and more widely used in various fields. In recent years, unmanned aerial vehicle (UAV) inspection technology has been widely used in transmission lines above 110kV voltage level, and achieved good application results. However, because the operation of 10kV distribution line is much more complex than that of high-voltage transmission line, and the standardization of distribution equipment is low, the application effect of UAV inspection technology on distribution line is always unsatisfactory. Although some power enterprises have made continuous attempts, they have never formed an efficient and applicable UAV inspection technology system for distribution lines. In this paper, the operation characteristics of distribution lines and the existing working mode of manual inspection are deeply analyzed. At the same time, combined with the technologies of UAV carrying, attitude sensing and front-end identification, a practical implementation strategy of UAV patrol inspection of distribution line is proposed. It has guiding significance for expanding the application field of UAV and improving the efficiency of distribution line inspection.
Analysis of abnormal heating of 66kV dry-type air-core reactor grounding device
Authors: Yue Yun kai , Wu Tian bo
Published: March 2022

When dry-type air-core reactors are in operation, the surrounding grounding devices, fences and other closed structural parts are abnormally hot. Because there is no effective analysis and detection methods for concealed projects such as grounding devices, it brings great difficulties to on-site analysis of problems; this article is based on the site conditions Theoretical analysis and the use of ground penetrating radar detection technology to study a 66kV dry-type reactor grounding device abnormal heating problem, through the analysis of the detection results, it is found that the reason for the heating of the dry anti-grounding device is that the grounding device has a circulating current in the alternating field; The design and construction of grounding devices of dry-type air-core reactors in new projects will provide certain reference significance.
Modelling and design of parameters for fast simulation of electromagnetic transient in AC / DC hybrid microgrid
Authors: Zhao Guopeng , Zhang Youbo
Published: March 2022

AC/DC microgrids contain a large number of power electronic devices, and their frequent switching process will bring a huge amount of calculation to the electromagnetic transient simulation, thus reducing the simulation efficiency. The research on the external characteristics of the microgrid does not need to pay attention to the dynamic process inside the converter. Therefore, the equivalent simplification of mathematical model is used in this paper to reduce the amount of simulation calculation data of the electromagnetic transient model to achieve the purpose of improving simulation efficiency. This method is concise and efficient, which does not relay on the performance of computer or change the program algorithm of software. By simplifying the current loop with fast dynamic response in the control system, he time response capability of the model is improved, and the converter is replaced by a controlled voltage source, which reduces the dynamic process of frequent changes in the converter. Based on the mathematical equivalent simplified model of microgrid, an electromagnetic transient simulation model was established. Through simulation verification, the simulation efficiency can be significantly improved while the accuracy of the simulation results is guaranteed.
Fault Location Analysis in Active Distribution Network Based on Multi-population Genetic Algorithm
Authors: Ou Shifeng , Feng Bin , Qin Liwen , Yu Xiaoyong , Luo Yuteng
Published: March 2022

Because the fault location of active distribution network is a complex optimization model, the traditional genetic algorithm has the problems of premature and slow convergence when solving complex optimization problems. The switch function that can adapt to the switching of multiple distributed power sources in real time is proposed. Here, we proposed a novel method to locate the fault of distributed power distribution network based on a multi-group genetic algorithm. When locating the fault zone, The algorithm stipulates that the direction of the generator flowing to the electrical equipment is the forward direction of the transmission line. In this paper, multiple populations are used to search the solution range at the same time to ensure that the final solution is the global optimal solution, and the optimal individual retention algebra is used as the convergence condition to fully improve the solution speed, which is suitable for complex distribution networks with distributed power generation. The fault location model proposed in this paper is simulated by a numerical example, and the results show that the model can accurately find the fault point, and has validity and accuracy.
Research on intelligent pumped storage power station based on digital twins technology
Authors: Yan Jun , Zhou Jianzhong , Li Yuxin , Cao Xu , Sun Yong , Liu Baonan
Published: March 2022

In order to build a new power system and achieve the goal of carbon peak and carbon neutralization, intelligent power grid and large-scale intermittent new energy has developed rapidly, as a consequence, the situation of power grid is increasingly complicated. Pumped storage power station, as a key technology of energy storage, which can effectively coordinate the peak-valley contradiction of power grid, is gradually transforming to the direction of intelligence and digitalization. In this context, the development characteristics and difficulties of intelligent pumped storage power stations are explored. Based on BIM and GIS fusion technology, the hierarchical framework of digital twins of pumped storage power station is proposed, the construction of the digital twins of pumped storage power station is elaborated simultaneously. Two application cases of digital twins in pumped storage power stations are introduced combined with operation and maintenance, which provides technical support for intelligent construction of pumped storage power stations with high engineering practical significance.
Relative straggle of sputtering parameters as a potential measure of power conversion efficiency of Perovskite materials
Authors: Oyewande O.E. , Hikon O.E. , Aisida S.O. , Aizebeokhai A.P.
Published: March 2022

The growing demand for electricity necessitates the development of time-efficient computational methods in search of better solar energy-harvesting materials. One challenge has been ways to improve the power conversion efficiencies (PCEs) of potential harvesters.In this paper, an ion sputtering approach was used to study the problem of estimation of the power conversion efficiencies (PCEs) of perovskite solar device materials through their surface sputtering signatures. This rests on a hypothesis that the similarity between the phenomenon of photon excitation from light-sensitive absorbers, leading to electricity generation, and ejection of energetic particles from sputtered surfaces, could be exploited to estimate PCE. Hence, a Monte Carlo (MC) simulation of the sputtering of surfaces of perovskite materials with energetic ions was performed; and a number of quantities that could be used for the estimation of PCE were calculated. The results indicated that the relative straggle of surface sputtering parameters of the materials could be an effective measure of the theoretical maximum power conversion efficiencies of these materials. In particular, the relative straggle of the projected range of the ions in the respective materials was found to be close to reported experimental results of PCEs in the literature.
Molecular docking studies of Amidoxime-containing heterocyclic compounds from Zinc database against homology modelled PfADSL
Authors: Oduselu Gbolahan O. , Ajani Olayinka O. , Adebiyi Ezekiel F.
Published: March 2022

Malaria remains one of the most infectious life-threatening diseases in the world. The lingering effect of drug resistance by malarial parasites, especially Plasmodium falciparum, has made it essential for the continuous search for novel antimalarial drugs that can act on new protein targets and through new modes of action. Amidoxime functional groups have, in recent years, shown to be good incorporations in heterocyclic backbones due to their vast biological activities. Hence, the antimalarial activities of some amidoxime-containing heterocyclic compounds have been predicted using molecular docking studies to determine the binding affinities and the inhibition constants of the compounds. The amidoxime-containing compounds were downloaded from the ZINC database and docked, using Auto Dock vina, against the active sites of homology modelled Plasmodium falciparumadenylosuccinate lyase (PfADSL) as obtained from the SWISS-MoDeL. The grid box was constructed using 80, 80, and 80, pointing in x, y, and z directions, respectively, with a grid point spacing of 0.375 A. The post-docking analysis, which entails determining the hydrogen bond formed and the bond length between the compounds and the protein target, was carried out using AutoDockTools, LigPlot and PyMOLmolecular viewer. The docking studies showed that the compounds possess binding affinities ranging from -8.6 to- 5.7 kcal/mol, with ZINC2268942 having the lowest binding affinity. The presence of the amidoxime-functional group on the best hit contributed significantly to the hydrogen bonds formed between the compound and the binding sites of PfADSL,which were observed atThr 124D, Ser 125D, Thr 172C, His 173C, Gln 250D, and Ser 299A. The results obtained from the molecular docking studies will be helpful in the development of a potential antimalarial drug that can target PfADSL after careful experimental validation of the target, then in vitro and in vivo screening.
Controllable multiple beam splitting in Hermitian and non-Hermitian symmetric coupled waveguide systems
Authors: Dou Fu-Quan , Wei Ya-Ting , Han Min-Peng , Sun Jian-An
Published: March 2022

We investigate high-fidelity multiple beam splitting in Hermitian and non-Hermitian (NH) symmetric coupled waveguides (WGs) with one input and 2 N output WG channels. In Hermitian systems, we realize adiabatically light splitting in resonant case based on the stimulated Raman adiabatic passage and arbitrary proportion from the middle WG to outer WGs in propagation coefficients mismatch case using shortcuts to adiabaticity (STA) technique. In NH systems with even WGs being dissipative, the compact and robust beam splitting can be achieved by eliminating the non-adiabatic coupling via the NH STA method. We further verify the feasibility of our theoretical predictions by means of the beam propagation method. The suggested multiple beam splitters open new opportunities for the realization of on-chip high-bandwidth photonics with high fidelity in short distances.
ARTS: autonomous research topic selection system using word embeddings and network analysis
Authors: Teruya Eri , Takeuchi Tadashi , Morita Hidekazu , Hayashi Takayuki , Ono Kanta
Published: March 2022

The materials science research process has become increasingly autonomous due to the remarkable progress in artificial intelligence. However, autonomous research topic selection (ARTS) has not yet been fully explored due to the difficulty of estimating its promise and the lack of previous research. This paper introduces an ARTS system that autonomously selects potential research topics that are likely to reveal new scientific facts yet have not been the subject of much previous research by analyzing vast numbers of articles. Potential research topics are selected by analyzing the difference between two research concept networks constructed from research information in articles: one that represents the promise of research topics and is constructed from word embeddings, and one that represents known facts and past research activities and is constructed from statistical information on the appearance patterns of research concepts. The ARTS system is also equipped with functions to search and visualize information about selected research topics to assist in the final determination of a research topic by a scientist. We developed the ARTS system using approximately 100 00 articles published in the Computational Materials Science journal. The results of our evaluation demonstrated that research topics studied after 2016 could be generated autonomously from an analysis of the articles published before 2015. This suggests that potential research topics can be effectively selected by using the ARTS system.
Piped water revenue and investment strategies in rural Africa
Authors: Armstrong Andrew , Hope Rob , Koehler Johanna
Published: March 2022

Viable pathways to universal safely managed drinking water access in rural Africa involve a blend of infrastructure types, service delivery arrangements, and sources of finance. Priorities are shaped by institutional and economic barriers and are often based on assumptions regarding user demand and revenue sustainability. Improved understanding of how alternative approaches affect revenue generated from user payments can enhance long-term viability and repayment capacity of rural piped water services. We analyse more than 3,900 monthly records from operators in Ghana, Rwanda, and Uganda and model revenue patterns for novel service area archetypes. Results indicate on and off premises connections exhibit complementary revenue patterns, with volumetric revenue determined by tariff level rather than connection type and waterpoints with the greatest dispensing capacity generating the most aggregate revenue. The prepaid credit payment approach, which is increasingly promoted to enhance revenue collection efficiency, is not associated with revenue advantages compared to pay-as-you-fetch and monthly billing approaches when tariff level is controlled. These patterns are recurrent at multi- and single country scales and across service areas where public and enterprise-led investment approaches to infrastructure development are taken, suggesting the findings may be applicable beyond the study domain. Infrastructure investment strategies can promote revenue and equity goals through off-site piped water, but more evidence is needed to understand the trade-offs of prepaid credit systems.
Infant Growth Trajectories and Lipid Levels in Adolescence: Evidence From a Chilean Infancy Cohort
Authors: Von Holle Ann , North Kari E , Gahagan Sheila , Blanco Estela , Burrows Raquel , Lozoff Betsy , Howard Annie Green , Justice Anne E , Graff Mariaelisa , Voruganti Saroja
Published: March 2022

Growth in early infancy is hypothesized to affect chronic disease risk factors later in life. To date, most reports draw on European-ancestry cohorts with few repeated observations in early infancy. We investigated the association between infant growth before 6 months and lipid levels in adolescents in a Hispanic/Latino cohort. We characterized infant growth from birth to 5 months in male (n = 311) and female (n = 285) infants from the Santiago Longitudinal Study (1991–1996) using 3 metrics: weight (kg), length (cm), and weight-for-length (g/cm). Superimposition by translation and rotation (SITAR) and latent growth mixture models (LGMMs) were used to estimate the association between infant growth characteristics and lipid levels at age 17 years. We found a positive relationship between the SITAR length velocity parameter before 6 months of age and high-density lipoprotein cholesterol levels in adolescence (11.5, 95% confidence interval; 3.4, 19.5), indicating higher high-density lipoprotein cholesterol levels occurring with faster length growth. The strongest associations from the LGMMs were between higher low-density lipoprotein cholesterol and slower weight-for-length growth, following a pattern of associations between slower growth and adverse lipid profiles. Further research in this window of time can confirm the association between early infant growth as an exposure and adolescent cardiovascular disease risk factors.
Development of a method for preparing cyclic nigerosylnigerose syrup and investigation of its value as a dietary fiber
Authors: Yasuda Akiko , Mizote Akiko , Miyata Manabu , Kurose Mayumi , Ogawa Toru , Sadakiyo Tsuyoshi , Uchida Satoko , Yamamoto Takuo , Mitsuzumi Hitoshi , Aga Hajime , Yamamoto Koryu
Published: March 2022

Cyclic nigerosylnigerose (CNN) syrup, containing 76% water-soluble dietary fiber, was prepared from starch on an industrial scale, using isoamylase, 6-α-glucosyltransferase, 3-α-isomaltosyltransferase, and cyclodextrin glucanotransferase. CNN syrup has a unique linkage pattern, consisting mainly of α-1,3 and α-1,6 glucoside linkages, and is characterized by its low weight average molecular weight (807) and moderate sweetness (relative sweetness = 25), unlike in well-known dietary fiber materials. The glass transition temperature of CNN is higher than that of the straight chain structures, maltotetraose and maltosyltrehalose. Even when 40% of normally added sucrose was replaced with CNN syrup, sponge cake puffed up sufficiently. The no observed adverse effect level for a single dose of CNN syrup was 0.88 and 0.89 g dry solid/kg body weight for men and women, respectively. The increase in blood glucose and insulin concentrations during consumption of CNN syrup was lower than that of glucose.