bluuebunny/crossref_metadata_2025 huggingface dataset:
The Relative Orientation between Local Magnetic Field and Galactic Plane in Low Latitude Dark Clouds
Authors: Choudhury Gulafsha B. , Das Himadri S. , Medhi B. J. , Pandey J. C. , Wolf S. , Dhar T. K. , Mazarbhuiya A. M.
Published: May 2022

In this work, we study the magnetic field morphology of selected star-forming clouds spread over the galactic latitude (b) range −10° to 10°. The polarimetric observations of clouds CB24, CB27 and CB188 are conducted to study the magnetic field geometry of those clouds using the 104 cm Sampurnanand Telescope (ST) located at ARIES, Manora Peak, Nainital, India. These observations are combined with those of 14 further low latitude clouds available in the literature. Most of these clouds are located within a distance range 140–500 pc except for CB3 (∼2500 pc), CB34 (∼1500 pc), CB39 (∼1500 pc) and CB60 (∼1500 pc). Analyzing the polarimetric data of 17 clouds, we find that the alignment between the envelope magnetic field (

θ

B

env

) and galactic plane (GP) (θ
GP) of the low-latitude clouds varies with their galactic longitudes (l). We observe a strong correlation between the longitude (l) and the offset (

θ

off

=
∣

θ

B

env

−

θ

GP

∣

) which shows that

θ

B

env

is parallel to the GP when the clouds are situated in the region 115° < l < 250°. However,

θ

B

env

has its own local deflection irrespective of the orientation of θ
GP when the clouds are at l < 100° and l > 250°. To check the consistency of our results, the stellar polarization data available in the Heiles catalog are overlaid on the DSS image of the clouds having mean polarization vector of field stars. The results are almost consistent with the Heiles data. A systematic discussion is presented in the paper. The effect of turbulence in the cloud is also studied which may play an important role in causing the misalignment phenomenon observed between

θ

B

env

and θ
GP. We have used Herschel (Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.) SPIRE 500 μm and SCUBA 850 μm dust continuum emission maps in our work to understand the density structure of the clouds.
Kano-FBS model: a data-driven innovative design approach for smart product-service system development
Authors: Ying Yuhan , Xiang Zhongxia , Cong Jingchen , Zhu Liming
Published: May 2022

Smart product-service system (Smart PSS), as an emerging digital paradigm, should meet user expectations and optimize their experience with a higher degree of sustainability. As a complex solution bundle with digital technology, its innovative design method differs from the existing method for traditional products. For a reason that massive user-generated data can be collected in the usage stage, which can be utilized to obtain new user requirements and calculate the user satisfaction degree. According to the real-time user preference information, some modules can be upgraded or adjusted in order to extend the lifecycle of the sustainable Smart PSS. Nevertheless, few studies focus on conducting innovative design by concerning massive information collected in the usage stage in a sustainable Smart PSS environment, let alone a novel approach to support the information re-use in product development of other fields. Aiming to fill this gap, a new innovative design methodology is proposed by combining Function-Behavior-Structure (FBS) and Kano model to guide Smart PSS development. User requirements and behaviors are predicted and analysed by forecasting and collecting information from the perspective of information. As an illustrative case study, a self-service medicine vending system is described to explain the proposed approach. This research provides guidance for Smart PSS in the medical field.
Human-Simulation Logical Control Research on Lifting Electromagnet System
Authors: Yongbiao Chen , Yan Ding , Wei Lin
Published: May 2022

The variability and randomness of the load bring certain difficulties to the control accuracy of the electromagnet. A novel human-simulation logical control research on liftingelectromagnet is studied in this paper. Based on the pan-Boolean theory, the logical control model for electromagnetic force control system is based on control practice and is consisted by a series of control rules. The dynamic control model of electromagnetic force control system is established in Matlab/Simu1ink, the simulation experimental results show that if adding the human-simulation logical controller, the overshoot of the system is smaller, the response speed is faster, and the steady-state accuracy is higher. The controller can better meet the working requirements of the lifting electromagnet.
Two-dimensional planar sound source localization based on microphone array
Authors: Zhang Yuqiao , Chen Danfeng , You Wenyang , Li Junlong , Du Maochun
Published: May 2022

In recent years, people’s awareness of wildlife protection has been increasing, and the demand for wildlife observation and recording has increased. However, the existing sound source localization system needs to continuously collect sound signals and convert the time-domain signals of the sound into frequency-domain signals. These shortcomings will increase the power consumption of the device, adversely affect the battery life, and the sound source localization result is easily interfered by the echo of environmental noise and target sound waves. In this study, the algorithm and hardware are improved on the basis of the existing sound source positioning system, which can improve the positioning accuracy and reduce the power consumption and cost of the whole machine. The adaptive circuit is used to filter and adjust the sound signal in real time to eliminate the influence of the difference between the individual microphones in the microphone array, which makes the sound source localization system more robust to the environmental noise and the echo of the target sound wave, and more suitable for the forest scene of wildlife protection. Through the research of this sound source localization system, we hope to provide some new ideas for producing economical and practical sound source localization equipment and lay a foundation for the intelligent development of wildlife protection in the future.
Discussion on tuning method of quantization factor of fuzzy PID controller
Authors: Di Yanjia , Chen Zili
Published: May 2022

Quantization factor is one of the main external parameters of a fuzzy PID controller, which has an obvious impact on the performance of the controller. The traditional setting methods do not reveal its inherent laws. In this paper, we take a specific fuzzy PID control system as the research object. Secondly, we study the influence of quantization factor on the performance of the controller in detail. We propose a new method of calculating quantization factor with probability coverage. Experiments are conducted to prove its rationality and effectiveness
Motor fault diagnosis based on teaching and learning gray wolf algorithm optimized support vector machine
Authors: Yu Maochang , Xiao Chun , Liu MengJie , Chen Jing , Yuan Ruiteng
Published: May 2022

To quickly and accurately identify motor faults, this paper proposes the gray wolf algorithm based on teaching and learning improvement to adaptively optimize the parameters of the multi-class support vector machine. Finally, based on the improved algorithm, the seven types of fault data such as the air gap eccentricity of the motor, the broken bar of the rotor, the bearing seat damage, and the bearing wear were carried out fault diagnosis experiments, and a comprehensive comparison and analysis were carried out with the widely used algorithm. The results show that the motor fault diagnosis accuracy rate of this method is 97.88%, which is better than other methods in classification accuracy.
Development of a low-cost EMG-data acquisition armband to control an above-elbow prosthesis
Authors: Schlüter Christoph , Caraguay Washington , Ramos Doris Cáliz
Published: May 2022

This work presents the development and implementation of an armband for EMG-data acquisition of the upper arm. The developed prototype serves for investigations on EMG-signal processing with the final objective of reliably controlling a prosthesis for a transhumeral amputee. To make the product available for a greatest possible number of people one of the main characteristics will be a design of very low cost. A focus is put on the electric circuit design. In order to manufacture the prototype without difficulties, it is exclusively designed with components, which are available on the Ecuadorian market. The development is based on previous investigations and approaches of other researchers. With help of electric circuit simulations, the design was adapted and optimized step by step and a reliable low-noise circuit was established. All components are arranged on printed circuit boards in a way to keep the device as small as possible. To optimally avoid noise the length of the connection from the electrodes to the amplifier is minimized. Compact 3D-printed housings cover all the electric components. All housings consist of only two parts and are intuitive to assemble. Holes in the bottom offer space to fix electrodes via a snap-fastener connection. 3D-printed elastic straps are designed to connect the subsystems and hold the device in place. The armband including two sensors weighs 92 g and is capable of measuring two muscles with a bipolar EMG-setting each, sharing one reference electrode, which is aligned on the side of the upper arm between the biceps and triceps muscles. The amplification of the sensors is adjustable individually by potentiometers, facilitating a gain factor range of 211 to 2016 V/V. The data is recorded by a microcontroller board and send to a computer for processing via wire or Bluetooth. For wireless operation, rechargeable batteries are integrated. Test measurements on an able-bodied human prove the functionality of the device.
Research on the rolling channel control of micro tailless air-to-ground missile
Authors: Liu Lin , Chen Yun , Zhao Tao , Lu Juanzhi , Ma Fei
Published: May 2022

Due to the limitation of volume and weight, the missile body parameters of the micro tailless air-to-ground missile have a large range during flight, and the characteristics of the rolling channel are greatly different from those of conventional missiles, the stability control of the roll channel is greatly affected by the error of the actuator. Under the classic PID control, the HWIL simulation results show that the jitter of roll angle is obvious, and the anti-disturbance ability of the system is poor. Based on the classic PID, fuzzy control is introduced to optimize the design of rolling channel by using fuzzy online self-correcting PID control. The results of the hardware-in-the-loop simulation show that the jitter of roll angle is suppressed, which improves the characteristics of the roll channel and the control efficiency.
Studying wearing resistance of graphene-based materials for the project of the first in the world probe microscope – Earth satellite by solar wind plasma emulation
Authors: Levine K.L. , Bespalova E.A. , Vankaev A.S. , Klyukina E.V. , Lopatin A.V. , Metalnikov N.M. , Saprykin M. E. , Loginov A.B. , Orazov I.V. , Khanin S.D. , Loginov B.A.
Published: May 2022

In situ monitoring the surface and structure stability of the constructional material in the conditions of outer space solar wind is an interesting scientific and engineering problem. For this purpose, as a part of the project of the first in the world probe microscope – space satellite, multilayered graphenes were plasma treated in conditions imitating solar wind and studied by scanning probe microscope in laboratory conditions. Accelerating factor of laboratory plasma treatment was estimated in order to compare the result with further solar wind exposure in outer space. Multilayered graphenes were selected for the study because if their promising properties as light shields – for equipment protection, as well as for material for solar sailing. It was found that plasma treatment affects surface morphology, and these changes correlate with the duration of the treatment. Thus, the applied method can be applied to simulate the erosional effect of the solar wind on structural materials in open space.
2D Local identification of the elasticity parameters of heterogeneous materials by the finite element model updating method
Authors: Ayeleh E , Atchonouglo K , Koumekpo Y , Germaneau A , Caillé L , Dupré J-C
Published: May 2022

This work is subjected to an identification of elasticity properties which are the Young’s modulus E and the Poisson’s ratio v of a heterogeneous material. We have created the experimental displacements by solving the direct problem. A re-calibration of the experimental and the simulated displacements is done based on the principle of the finite element model updating (FEMU). The minimization of the cost function obtained by the FEMU method in the inverse problem is done by Newton type algorithms. A complete study has been done by studying the sensitivity of the identified values with respect to the refinement of the mesh and with respect to the level of disturbance.
Study on hydraulic characteristics and internal flow mechanism of composite blade disc pump
Authors: Lian Xiaolong , Zhou Bo , Wang Chuan , Li Bin , Pei Yingju , Dong Qiyu
Published: May 2022

Disc pump is widely used in difficult-pump-medium transportation such as petroleum and chemical industry. Discontinuous blade impellers play an important role in the passability and energy efficiency of disk pump. The research of design and internal flow mechanism are particularly important. Based on the structural characteristics and the internal flow mechanism of the original model, the improved design of the blade structure is carried out. Through the experimental verification and the numerical analysis of multiple working conditions, the influence law of the new composite blade on the hydraulic characteristics and internal flow mechanism of the disc pump is obtained. The results show that the error of energy efficiency characteristics of simulation and experiment under different flow conditions is within 5%, and the accuracy of simulation results meets the requirements; The hydraulic characteristics of the improved model are about 5.8% higher than that of the original model. The driving force of the new composite blade is more sufficient and the flow field is improved more obviously; The low pressure is located in the center of the impeller and gradually increases to the outlet of the impeller. There is obvious energy and mass conversion between the bladed region and bladeless region. The research results can provide a reference for the structural design of disc pump composite blade and the analysis of internal flow mechanism.
Effect of filler on adhesion characteristics of precursor ceramic coating against high-temperature molten ash
Authors: Zhang Bing , Zhang Yinning , Li Jin , Wang Jinqing , Zheng Zhongrui , Shen Zhibin , Lin Xiguang , Li Min
Published: May 2022

In view of the widespread high-temperature molten ash adhesion problem of heat exchanger surface in the chemical, power, metallurgy and other industries, precursor ceramic coating is proposed to reduce ash adhesion strength. Three ceramic coatings were obtained by adding hexagonal boron nitride (h-BN), zirconia (ZrO2) and aluminium oxide (Al2O3) inert fillers on TP347 steel sheets through the Czochralski method and high-temperature sintering. Results of the static contact angle test show that at 860°C, the contact angles of the molten ash on the coating surfaces of h-BN, ZrO2 and Al2O3 are 58°, 54° and 53°, respectively, which are greater than that (39°) of the steel sheet sample. The spreading radiuses of the three coatings are significantly less than that of the bare sample, indicating a strong anti-adhesion performance, in which the h-BN coating is the best. Spreading dynamic analysis of the bare and h-BN coating samples reveals that the spreading dynamics of both sample surfaces is driven by a combination of reaction, dissolution and diffusion. The inert filler in the coating makes the reaction and dissolution of molten ash on the coating surface weaker than those of the steel sheet. The micromorphology of the melt ash-sample sheet cross-section shows that the melt ash binds closely to the steel sheet sample oxide layer, whereas the boundary with the coating is clear and obvious. This result indicates that the coating can effectively weaken the wetting and permeability of the molten ash. The research results provide new ideas for precursor ceramic coating to solve the high-temperature melting ash adhesion problem of the heat exchanger surface.
Inhibition effect of cow bone soot on low carbon steel corrosion in artificial concrete pore environment
Authors: Loto Roland T. , Busari Adebola Ayobami
Published: May 2022

The corrosion inhibition of cow bone soot (BAS) at 5%, 10%, 15% and 20% weight on low carbon steel (LCS) in artificial concrete pore solution was evaluated with potentiodynamic polarization and current-time displacement. BAS visibly decreased the corrosion rate of LCS from 7.31 x 102 mm/y at 0% BAS to 1.45 x 102 mm/y at 20% BAS concentration. Maximum inhibition performance of 80.18% was obtained at 20% BAS concentration. The inhibition mechanism of BAS was determined to be anodic type. Cathodic reduction of the polarization plot was significant due to decrease in O2 adsorption. Plot of current versus time shows BAS reduces the thermodynamic tendency of LCS to corrode.
Applicability of wind products retrieved from wind lidar in the winter games
Authors: Chen Yajun , Li Linwei
Published: May 2022

Based on the 10-min average wind speed and wind direction data observed by automatic stations at the starting point and midway of the snow track in the “14th National Winter Games”, the wind product accuracy of wind lidar from December 1, 2019 to January 31, 2020 was analyzed. The results show that the mean relative deviation (MRD), standard deviation of relative deviation (STDRD
) and correlation coefficient (R) of wind direction data are better than wind speed data. The MRD is largest when the average wind speed of the ground observation is about 3 m/s, reaching 55%. The wind speed retrieved by the lidar is higher than that observed by automatic station when the average wind speed is lower than 10 m/s. When the average wind speed is higher than 10 m/s, the wind speed retrieved by the lidar is lower than ground observations. The detection accuracy of the lidar wind direction at the automatic station No.4 is better than that at the automatic station No.3. For the detection of wind speed, the mean absolute error (MAE) is larger, the R was slightly lower, but the mean error (ME), the MRD and the STDRD
are better at the automatic station No.4. As the SNR increases, ME of the average wind speed decreases, and the relative deviations (RD) of wind speed and wind direction gradually concentrate on zero.
Reducing labyrinth seal leakage with application of axially arranged baffles with increasing height
Authors: Zhang Mingjie , Yang Jiangang , Zhang Wanfu , Gu Qianlei
Published: May 2022

For turbomachines, reducing seal leakage is beneficial for increasing the efficiency and reducing the energy consumption. This study proposes the design of the axially arranged baffles with increasing height to reduce the leakage of the labyrinth seal. Due to the existence of the axially arranged baffles with increasing height, the leakage fluid is guided to flow into the seal cavities. In each seal cavity, one large vortex is induced, and additional small vortexes are induced in the regions between adjacent baffles. The leakage flow resistance and kinetic energy dissipation of the leakage fluid are enhanced. To demonstrate the effectiveness of the new design, numerical comparisons are conducted between the labyrinth seals with and without axially arranged baffles with increasing height. Results show that the new seal can reduce the leakage flow rate by 37.7-38.8% compared with the labyrinth seal.
Application of BMC counter shaft drilling rig in the return wind vertical shaft in Hengsheng coal mine
Authors: Feng Xuewen , Meng Guoying , Xu Yiyang
Published: May 2022

In order to make full use of the less humanized and intelligent features of the BMC counterbore drilling rig, and effectively improve the construction efficiency of the return wind river and the transmission rate of the steady straight guideway in coal mines, taking the Heng Sheng coal mine with different regional characteristics as an example, the field application of the BMC back hole drilling rig return wind riser was carried out at the designated location in the mine area, realizing the construction of the preset trajectory of the less personified return wind river and laying the foundation for the subsequent tunnel ventilation. At the same time, in response to the many problems in the drilling process, the solution of drilling a stable and straight pilot hole in the pre-process of the BMC counter shaft drilling rig was proposed, which effectively improved the construction efficiency of the return wind vertical shaft, reduced the construction danger of the construction personnel, and ensured the safe and orderly production of the mine.
Performance prediction through experiments of recuperator to be installed in turboshaft engine for unmanned aerial vehicle
Authors: Lee Sangrae , Kim Jae-hoon
Published: May 2022

It is developing an engine for an unmanned aerial vehicle that performs missions without a person in the turboshaft method. This engine is equipped with a recuperator to drive the engine with higher efficiency, which can extend the distance for performing a given aircraft’s mission. This study evaluates the various performances (heat exchange efficiency and pressure loss) of a recuperator developed for the purpose of installing it on the 100-horsepower engine and conducts the tests in various engine driving environments. These results can more accurately predict the performance of the engine to be developed and can serve as an opportunity to further increase engine efficiency.
Evaluation of IR micro-grid livestock wellbeing monitoring stand
Authors: Rizanov Stefan , Yakimov Peter , Stoynova Anna
Published: May 2022

Infrared thermography (IRT) and its application for livestock state-of-health monitoring has been a focal point of many research works over the past 10 years. IRT is a powerful tool for detection and evaluation of localized inflammation sites. With most works centered around utilization of complex and expensive IR imaging devices - we investigated the prospect of developing a cost-effective automated monitoring stand with the application of simple IR micro-grid scanning end-devices.
Research on Four Different Designs of Comparator
Authors: Zhu Haomin
Published: May 2022

Comparators contribute a significant role to analogue to digital converters (ADC). This paper describes and evaluates four excellent comparator optimisation schemes in recent years and analyses their advantages and disadvantages, providing ideas for the following comparator research direction. In addition, this paper introduces the design steps of each comparator optimisation scheme. It shows how the designer completes the final optimisation scheme step by step from the practical problems, which provides a specific reference for the comparator designers in the future. A double-tail latch-type comparator with dynamic bias adds a tail capacitor to the pre-amplifier to achieve low noise and high gain. Furthermore, a triple-tail dynamic comparator addresses a cascoded integrator. The new stage defines and attenuates the noise to achieve high speed and low noise. Compared to the triple-tail comparator, another design of a three-stage comparator is through adding a feedforward path between the first amplifier/latch and third latch to construct a triple-latch feedforward dynamic comparator. It is aimed to reduce delay and get low consumption in the region of the high voltage signal. Moreover, Edge-Pursuit Comparator (EPC) uses NAND gates and inverter delay cells to generate the comparison result between two input signals. Its circuit structure allows input noise tunability, automatic energy scaling, and low voltage tolerance.
Research on UAV’s Automatic Hang Method For Auxiliary High-voltage Transmission Line Device
Authors: Liu Lanlan , Jiang Zhipeng , Wang Feng , Zou Dehua , Wang Zhenyu , Yang Jiani
Published: May 2022

With the rapid development of high-voltage transmission networks, the coverage of overhead transmission lines has become wider and wider. The overhaul of live work is also becoming more frequent. In order to improve the efficiency of live maintenance, this paper proposes a mechanism that uses a large-load unmanned aerial vehicle (UAV) to carry a wire-hanging mechanism by using the combination of U AV and machine vision. The new method based on the Local Binary Pattern (LBP)vision system to identify the wire realizes one-key hookup, and achieves the purpose of assisting the inspection robot and the online operation of live workers. This method can effectively solve the bottleneck problems of robot practicality such as the cumbersome online and offline process of robots and intelligent control of the operation process. It has important engineering application value for improving the modern live operation level of power transmission lines and the energy efficiency and intelligence of power grid operation.
Research on ultrasonic location method of partial discharge in switchgear based on TOA algorithm
Authors: Jing Xin , Cao Zhen , Yu Lei
Published: May 2022

In view of the problem that the partial discharge location of switchgear still needs to detect the amplitude of multiple cabinets, and then can be roughly located only through the calculation and review of workers, an ultrasonic receiver is placed in the switchgear to calculate and locate the ultrasonic location of partial discharge. In the experiment, the model simulation is used to verify that the ultrasonic receiver terminal maintains excellent positioning effect under different installation positions.
Research on ordered charge and discharge of Electric Vehicles and their effects
Authors: Gu Jinhui , Guo Chunlin
Published: May 2022

Based on the control strategy of ordered charge and discharge of electric vehicles, the control strategy of ordered charge and discharge is proposed. The control strategy of the minimum variance minimum differential peak and valley load as the goal, and will be the charge and discharge time of electric vehicles and the charge and discharge requirements as constraint conditions, the optimal solution given by the method of charging control flow diagram and orderly, according to the actual place residential distribution network structure, based on MATLAB/simulink to establish the simulation model of the distribution network. The simulation results show that the proposed orderly charge-discharge strategy can effectively complete the “peak-valley filling”, reduce the daily maximum load increment and reduce the peak-valley difference.
Analysis and control of the single-stage AC/DC LLC resonant converter
Authors: Yue Yuge , Wang Guangzhu
Published: May 2022

LLC resonant converter can meet the requirement of many load applications such as electric vehicle charging station because of the high efficiency and low cost. However, less research has been done in AC/DC LLC resonant converter. This paper presents a single stage AC/DC LLC resonant converter. It can maintain the output voltage with an AC input. Besides, in the single-stage converter, PFC can be achieved without other auxiliary PFC circuit. The simulation results indicate that the presented topology and control method can achieve a stable output voltage of 200V at rated power of 1kW. Besides, PFC function can be realized. It provides a theoretical basis for the AC/DC power conversion applications.
A variable parameter control method for charging pile load aggregator to participate in the fast frequency market
Authors: Chen Jihuan , Zhang Yang , Liu Haifeng , Xing Jianxu , Lu Feng , Zheng Songsong , Zhao Rui
Published: May 2022

With the access of large-scale new energy sources, fast frequency regulation resources of the power system are scarce. A variable parameter control method for charging pile load aggregator to participate in the fast frequency market is proposed in this paper. It is that charging pile load aggregator actively adjusts the active power according to the frequency of the local power system, and the response speed is within 0-2 seconds. In addition, the variable parameter control method proposed in this paper specifically controls the power of charging pile according to the speed and amplitude of frequency drop, which has strong pertinence and simple control scheme, and further improves the frequency stability of the power grid.
Research on the capacity configuration of the “flywheel + lithium battery” hybrid energy storage system that assists the wind farm to perform a frequency modulation
Authors: Yuan Man , Tian LiJun , Jiang Tao , Hu RongBin , Cui Xiaojie
Published: May 2022

In order to reduce the adverse impact of wind power fluctuations on the primary frequency modulation of the grid, based on the operation data and frequency modulation performance of the wind farm power generation equipment, the analysis is carried out, and combined with the characteristics of the “flywheel + lithium battery” hybrid energy storage system, a random time delay hybrid system is constructed. Using wavelet packet to decompose wind power grid-connected power, decoupling lithium battery energy storage and flywheel energy storage components. In order to achieve the goal of maximizing the net present value (NPV), the minimum average annual energy storage cost is taken as the objective function, and the pattern search method based on the Hooke-Jeeves method in the direct search method is used to solve the problem. The simulation results show that the research can ensure the frequency modulation performance of the wind farm-energy storage hybrid system, and at the same time determine the wind farm supporting energy storage capacity based on economic optimization, and the configuration of flywheel energy storage and lithium batteries in the hybrid energy storage system to improve the overall economic benefits of the system.
A method of power-electronized supply accommodation capacity analysis for receiving-end grid based on multi-objective optimization
Authors: He Hailei , Lu Runzhao , Gao Xin , Zhang Jian , Jian Qingzhi , Li Wensheng
Published: May 2022

With the development of renewable energy and high voltage direct current (HVDC) system, the proportion of power-electronized supply in power system is increasing. It creates challenges to the safe and stable operation of the receiving power grid. Reasonable evaluation of the scale of power-electronized supply that can be carried by the receiving-end grid is of great significance to guide power grid construction and maintain its operational safety. Firstly, this paper explains the theory that the unified effective short circuit ratio (UESCR) can reflect the static voltage stability of buses. Then, a multi-objective optimization model, which considers the external dc feed-in, local renewable energy, unit output, and operation constraints, is established to obtain the power-electronized supply accommodation capacity. And it is solved repeatedly by means of cyclic increasing dc feed-in scale and renewable energy penetration. Finally, the effectiveness and practicability of the proposed method are verified in a modified IEEE 39 bus system.
Identification method of abnormal data of electric energy measurement based on BP neural network algorithm
Authors: Liu Shengnan , Ye Zhanqing , Yi Ling , Li Min
Published: May 2022

The problem of unclear power load type exists in the conventional abnormal data identification method of electric energy metering, which leads to a high error percentage. A method of abnormal data identification of electric energy metering based on BP neural network algorithm is designed. In this paper, the data of electric energy measurement are obtained and used to calculate the active power loss. It adjusts the connection weights and thresholds between neurons according to the error function of sample size. In this paper, BP neural network algorithm is used to identify the type of power load, and the time balance data set is constructed. According to the data set discriminant analysis of key behavior pattern characteristics, the abnormal data recognition of power measurement is completed. The experimental results show that the average error percentage of the abnormal data identification method of electric energy measurement in this paper is 0.0233, 0.0530, 0.0539 and 0.0524, respectively, compared with the other three abnormal data identification methods of electric energy measurement. The abnormal data identification method of electric energy measurement in a plain text has higher reliability.
Insulation failure evaluation of SF6 circuit breaker relay coil based on high-frequency equivalent model
Authors: Qin Jian , Peng Yanjun , Wang Lu , Pan Ningbo , Chen Jianxi , Huang Yongqiang , Jiang Wei
Published: May 2022

In order to evaluate the insulation failure of SF6 circuit breaker relay coil, the finite element model of the relay coil was established, and the capacitance inductance matrix was calculated by simulation calculation, and the high-frequency equivalent circuit model of the coil was established. Inject low-voltage square wave pulse signal at the input end of the circuit, and the response curve is detected at the end of the circuit, and the characteristic curve is obtained by combining the response curve under the condition of inter-turn short circuit fault and no fault. The wavelet packet - energy spectrum analysis shows that the energy proportion of each frequency band of the characteristic curve changes when the short-circuit position between turns is different. Taking energy spectrum as input and combining with extreme learning machine to locate inter-turn short circuit fault, the simulation sample analysis shows that the correct rate of fault location is 93.3%.
Research on the influence of distributed generation and its grid connection on power system
Authors: Wu Zhongchao
Published: May 2022

China’s per capita resources are scarce and consumed very quickly. New energy power generation has the characteristics of green, environmental protection and renewable, and it is the main development direction of the current and future power industry. With the continuous expansion of new energy power generation and grid-connected scale, various adverse effects brought to the power grid in the process of grid-connected are gradually emerging and becoming more and more serious.This paper briefly introduces the distributed power generation, and then studies and analyzes various problems brought by the grid connection of new energy to the power system from the four aspects of grid voltage, grid harmonics, grid frequency, and grid protection, and gives some solutions. For example, if the power generation equipment meets the grid-connection standard, a real-time monitoring device for power quality and a dynamic reactive power compensation device can be installed; for harmonic pollution problems, multi-pulse converters and power filter devices can be used; for power quality problems in the distribution network, the structure of the power grid can be optimized., Reasonable selection of the impedance ratio of the circuit, etc.
Research on identification of cable sheath defects based on current analysis of cable sheath
Authors: Hongtao Ren , Ying Zhang
Published: May 2022

This paper presents a method to detect the different types of defects in cross connected cable sheath in a flat 500kV three leaf high voltage cable system with sheath current as input data. Three different defects are analyzed: the loss of electrical continuity of grounding, the short circuit between metal sheath of cable joint segment and the immersion of junction box. The model of cable system is simulated by theoretical analysis and ATP software. The results obtained by these two methods have achieved good consistency.
Aircraft Detection in Remote Sensing Imagery Based on Improved YOLOv4
Authors: Liu Dawei , Gao Shujing
Published: May 2022

A method is provided to resolve the issues of false recognition and lower recall of the you only look once version 4 (YOLOv4) algorithm in the aircraft targets prediction of remote sensing imagery. The method is based on the YOLOv4. According to the characteristics of small size and intensive arrangement of aircraft targets in remote sensing images, the backbone is mended to boost the prediction capacity of smaller targets. To strengthen the transmission and reuse of network features, the connection mode of the residual module in YOLOv4 is changed to the dense connection mode, and the five residual blocks in the backbone network are modified to the corresponding dense connection blocks to reduce the network layers and model redundancy. The experiment results reveal that compared with the YOLOv4, our method can enlarge targets features in smaller image regions, thereby availably increasing the prediction precision of aircraft targets.
Implementation and optimization of the PTOLEMY transverse drift electromagnetic filter
Authors: Apponi A. , Betti M.G. , Borghesi M. , Canci N. , Cavoto G. , Chang C. , Chung W. , Cocco A.G. , Colijn A.P. , D'Ambrosio N. , de Groot N. , Faverzani M. , Ferella A. , Ferri E. , Ficcadenti L. , Gariazzo S. , Gatti F. , Gentile C. , Giachero A. , Hochberg Y. , Kahn Y. , Kievsky A. , Lisanti M. , Mangano G. , Marcucci L.E. , Mariani C. , Messina M. , Monticone E. , Nucciotti A. , Orlandi D. , Pandolfi F. , Parlati S. , Pérez de los Heros C. , Pisanti O. , Polosa A.D. , Puiu A. , Rago I. , Raitses Y. , Rajteri M. , Rossi N. , Rozwadowska K. , Ruocco A. , Strid C.F. , Tan A. , Tully C.G. , Viviani M. , Zeitler U. , Zhao F.
Published: May 2022

The PTOLEMY transverse drift filter is a new concept to
enable precision analysis of the energy spectrum of electrons near
the tritium β-decay endpoint. This paper details the
implementation and optimization methods for successful operation of
the filter for electrons with a known pitch angle. We present the
first demonstrator that produces the required magnetic field
properties with an iron return-flux magnet. Two methods for the
setting of filter electrode voltages are detailed. The challenges of
low-energy electron transport in cases of low field are discussed,
such as the growth of the cyclotron radius with decreasing magnetic
field, which puts a ceiling on filter performance relative to fixed
filter dimensions. Additionally, low pitch angle trajectories are
dominated by motion parallel to the magnetic field lines and
introduce non-adiabatic conditions and curvature drift. To minimize
these effects and maximize electron acceptance into the filter, we
present a three-potential-well design to simultaneously drain the
parallel and transverse kinetic energies throughout the length of
the filter. These optimizations are shown, in simulation, to achieve
low-energy electron transport from a 1 T iron core (or 3 T
superconducting) starting field with initial kinetic energy of
18.6 keV drained to < 10 eV (< 1 eV) in about 80 cm. This
result for low field operation paves the way for the first
demonstrator of the PTOLEMY spectrometer for measurement of
electrons near the tritium endpoint to be constructed at the Gran
Sasso National Laboratory (LNGS) in Italy.
Composite design bioinspired by the mesocarp of Brazil nut (Bertholletia excelsa)
Authors: Sonego M , Sciuti V F , Vargas R , Canto R B , Pessan L A
Published: May 2022

The mesocarp of Bertholletia excelsa is a rich source of inspiration for strong, stiff and damage-tolerant composites. The bioinspired composites developed here are composed of an epoxy matrix with a 3D printed polylactic acid reinforced with 30% of carbon fiber (PLA-30CF) inspired in fibers, and syntactic foam inspired by sclereids. Monotonic and cyclic four-point bending tests and compact tension fracture toughness tests were carried out assisted by digital image correlation (DIC) to evaluate flexural properties, damage tolerance, and the R-curve of the composite. Its microstructure and fracture surface were analyzed by scanning electron microscopy. The mechanical performance of the bioinspired composite is promising: density of 1.0 g cm−3, flexural apparent elastic modulus of 1.6 GPa, and flexural strength six times higher than the neat epoxy, i.e. 17 MPa. Although the PLA-30CF printed structure led to a rising R-curve, the syntactic foam needs optimization to have a synergistic effect.
Folding-assisted plasmonically induced transparency in coupled graphene nanodisks
Authors: Wang Weihua , Zhang Rui
Published: May 2022

Plasmonically induced transparency (PIT), a classical analog of electromagnetically induced transparency in quantum systems, could offer an efficient way to engineer light–matter interaction and thus achieve particular manipulation of light. To realize PIT, the crucial point is the design of two strongly coupled modes, with one bright and the other dark. Common practice often takes dipole resonance as the bright mode, and higher-order resonance as the dark one. Here we present an alternative scheme to realize PIT in coupled graphene nanodisks through mechanical folding, where only fundamental dipole resonances are involved, and the dark mode is derived from two nondegenerate dipole resonances in a folded nanodisk. Two parameters (the folding angle

θ

and rotating angle

φ

) arising from folding can be utilized to tune the PIT. They determine two different PIT windows separately. By varying either one of them, single-window PIT can be switched to double-window PIT, and vice versa. In addition to mechanical operations, the proposed PIT can also be actively tuned by electrostatic gating. To properly understand the mechanism, a theoretical model of two coupled harmonic oscillators is presented, from which the predictions show good agreement with simulations.
Preimplantation triclosan exposure alters uterine receptivity through affecting tight junction protein
Authors: Dong Guangzhu , Sun Rundong , Zhang Rui , Qin Yufeng , Lu Chuncheng , Wang Xinru , Xia Yankai , Du Guizhen
Published: May 2022

Triclosan is a broad-spectrum antibacterial agent and widely exists in environmental media and organisms. Triclosan exposure has been reported to have adverse effects on reproduction including embryo implantation disorder. During the embryo implantation window, it is vital that the endometrium develops into a receptive state under the influence of ovarian hormones. However, the effect of triclosan on embryo implantation and endometrial receptivity remains unclear. In the current study, we found a decreased embryo implantation rate, serum estrogen, and progesterone levels in mice exposed to triclosan from gestation days 0.5 to 5.5. Through RNA sequencing (RNA-seq), we identified nearly 800 differentially expressed genes, which were enriched in various pathways, including uterus development, inflammatory response, and immune system processes. Among those enriched pathways, the tight junction pathway is essential for the establishment of the receptive state of the endometrium. Then, genes involved in the tight junction pathway, including Cldn7, Cldn10, and Crb3, were validated by quantitative real-time polymerase chain reaction and the results were consistent with those from RNA-seq. Through immunofluorescence staining and western blotting, we confirmed that the tight junction protein levels of CLDN7 and CRB3 were increased. All these findings suggest that preimplantation triclosan exposure reduces the rate of embryo implantation through upregulating the expression of the tight junction genes and affecting the receptivity of the endometrium. Our data could be used to determine the sensitive time frame for triclosan exposure and offer a new strategy to prevent implantation failure.
Genetic characterization of a missense mutation in the X-linked TAF7L gene identified in an oligozoospermic man
Authors: Ling Li , Li Fangfang , Yang Pinglan , Oates Robert D , Silber Sherman , Kurischko Cornelia , Luca Francis C , Leu N Adrian , Zhang Jinwen , Yue Qiuling , Skaletsky Helen , Brown Laura G , Rozen Steve G , Page David C , Wang P Jeremy , Zheng Ke
Published: May 2022

Although hundreds of knockout mice show infertility as a major phenotype, the causative genic mutations of male infertility in humans remain rather limited. Here, we report the identification of a missense mutation (D136G) in the X-linked TAF7L gene as a potential cause of oligozoospermia in men. The human aspartate (D136) is evolutionally conserved across species, and its change to glycine (G) is predicted to be detrimental. Genetic complementation experiments in budding yeast demonstrate that the conserved aspartate or its analogous asparagine (N) residue in yeast TAF7 is essential for cell viability and thus its mutation to G is lethal. Although the corresponding D144G substitution in the mouse Taf7l gene does not affect male fertility, RNA-seq analyses reveal alterations in transcriptomic profiles in the Taf7l (D144G) mutant testes. These results support TAF7L mutation as a risk factor for oligozoospermia in humans.
Elongating porcine conceptuses can utilize glutaminolysis as an anaplerotic pathway to maintain the TCA cycle
Authors: Seo Heewon , Kramer Avery C , McLendon Bryan A , Cain Joe W , Burghardt Robert C , Wu Guoyao , Bazer Fuller W , Johnson Greg A
Published: May 2022

During the peri-implantation period of pregnancy, the trophectoderm of pig conceptuses utilize glucose via multiple biosynthetic pathways to support elongation and implantation, resulting in limited availability of pyruvate for metabolism via the TCA cycle. Therefore, we hypothesized that porcine trophectoderm cells replenish tricarboxylic acid (TCA) cycle intermediates via a process known as anaplerosis and that trophectoderm cells convert glutamine to α-ketoglutarate, a TCA cycle intermediate, through glutaminolysis. Results demonstrate: (1) that expression of glutaminase (GLS) increases in trophectoderm and glutamine synthetase (GLUL) increases in extra-embryonic endoderm of conceptuses, suggesting that extra-embryonic endoderm synthesizes glutamine, and trophectoderm converts glutamine into glutamate; and (2) that expression of glutamate dehydrogenase 1 (GLUD1) decreases and expression of aminotransferases including PSAT1 increase in trophectoderm, suggesting that glutaminolysis occurs in the trophectoderm through the GLS-aminotransferase pathway during the peri-implantation period. We then incubated porcine conceptuses with 13C-glutamine in the presence or absence of glucose in the culture media and then monitored the movement of glutamine-derived carbons through metabolic intermediates within glutaminolysis and the TCA cycle. The 13C-labeled carbons were accumulated in glutamate, α-ketoglutarate, succinate, malate, citrate, and aspartate in both the presence and absence of glucose in the media, and the accumulation of 13C-labeled carbons significantly increased in the absence of glucose in the media. Collectively, our results indicate that during the peri-implantation period of pregnancy, the proliferating and migrating trophectoderm cells of elongating porcine conceptuses utilize glutamine via glutaminolysis as an alternate carbon source to maintain TCA cycle flux.