bluuebunny/crossref_metadata_2025 huggingface dataset:
Data‐driven cooperative adaptive cruise control for unknown nonlinear vehicle platoons
Authors: Lan Jianglin
Published: August 2024

This article studies cooperative adaptive cruise control (CACC) for vehicle platoons with consideration of the unknown nonlinear vehicle dynamics that are normally ignored in the literature. A unified data‐driven CACC design is proposed for platoons of pure automated vehicles (AVs) or of mixed AVs and human‐driven vehicles (HVs). The CACC leverages online‐collected sufficient data samples of vehicle accelerations, spacing, and relative velocities. The data‐driven control design is formulated as a semidefinite program that can be solved efficiently using off‐the‐shelf solvers. Efficacy of the proposed CACC are demonstrated on a platoon of pure AVs and mixed platoons with different penetration rates of HVs using a representative aggressive driving profile. Advantage of the proposed design is also shown through a comparison with the classic adaptive cruise control (ACC) method.
Energy optimization dispatch based on two‐stage and multi‐objective comparative analysis for PV and BESS integrated fast charging stations with V2G
Authors: Zhan Shuhe , Zhou Yun , Feng Donghan , Wang Haojing , Fang Chen
Published: August 2024

As an effective way to promote the usage of electric vehicles (EVs) and facilitate the consumption of distributed energy, the optimal energy dispatch of photovoltaic (PV) and battery energy storage systems (BESS) integrated fast charging stations with vehicle‐to‐grid is of considerable value to the efficient use of renewable energy. Based on an examination of the electrical structure and operation modes of PV and BESS integrated fast charging stations, considering the randomness of EVs’ arrival and departure, a rolling optimization strategy is adopted. Combining the energy architecture characteristics of the charging stations, the economic dispatch model is established by scheduling the orderly charging and discharging of EVs and the BESS to minimize the expense of daily operations. In view of the shortcomings of the first‐stage economic dispatch, two further optimization strategies are proposed to level out the power fluctuation of the grid connection point (POC) of the charging station, and the effect of the two‐stage optimization model and the multi‐objective optimization model are studied in comparison. Finally, an intraday real‐time optimization algorithm is designed, and the similarities and differences of the economic index and power fluctuation index are comprehensively analysed by using an actual charging station as a case study.
Analysis of single-crystal 3C-SiC subsurface damage mechanisms based on molecular dynamics indentation speed
Authors: Le Jianbo , Liu Juan , Liu Jian , Jiang Hong , Li Jiao , Yu Dongling
Published: August 2024

In order to explore the subsurface damage of single crystal 3C-SiC at different indentation speeds, molecular dynamics model of nanoindentation under a diamond indenter is constructed. The impact of varying indentation speeds on the formation of subsurface damage is thoroughly analyzed. Combining the diamond structure identification method and dislocation analysis, three indentation speeds of 50, 250, and 450 m/s are selected. From several perspectives, such as load–displacement curves, volumetric strain, atomic bond breaking, and dislocation evolution processes, the effect of different indentation speeds on the subsurface damage of single-crystal 3C-SiC is deeply investigated. When the indentation speed is 50 m/s, as the depth of the indentation increases, workpieces are more susceptible to elastic–plastic deformation under the action of external forces, and volumetric strain is significantly increased. At the indentation speed of 50 m/s, with a higher dislocation density, the atoms rearrange around the dislocation and more dislocation loops are formed. The atoms are also more closely arranged, and the local structure is more distorted. This leads to a high peak of C–Si in the radial distribution function, which reflects the irregularity of local atomic arrangement and the concentration of distribution. At the 50 m/s indentation speed, the elastic–plastic deformation of the workpiece leads to grain boundary stress concentration and damage. Grain evolution occurs with fractures and dislocations. The squeezing between atoms is strong, atomic bonds are broken and connected frequently, and subsurface damage is significant.
Modeling of the handshake channel and characteristic analysis
Authors: Liao Wei , Meng Ziyi , Zhou Lingli
Published: August 2024

Human body communication technology with human biological tissue as a communication medium provides a new way for wireless communication. However, the current research on human body communication technology is limited to single body communication. This paper expands the application of human body communication technology through the study of two-person handshake communication. First, the impedance and size of the transmitter and receiver were discussed to reduce the influence of the transmitter and receiver on path loss. Then, the effects of palm contact areas on path loss was analyzed in the ultra-wide band (UWB) high and human body communication (HBC) low bands. Finally, the safety of human communication technology was evaluated based on whether the local maximum specific absorption rate (SAR) reached the international limit. In this paper, the path loss was calculated at different communication distances with the optimal parameters of the transmitter and receiver. Under the same communication distance, with the decrease in the contact area of two people’s palms, the path loss of UWB and HBC bands gradually decreases. By comparing SAR values in different frequency bands, it was found that communication through the human body is safe, and the SAR in HBC is smaller than that in UWB. Furthermore, it is less affected by changes in the palm contact area.
The Velocity Aberration Effect of the CSST Main Survey Camera*
Authors: Feng Hui-Mei , Cao Zi-Huang , Lam Man I. , Li Ran , Tian Hao , Zhang Xin , Wei Peng , Li Xin-Feng , Wang Wei , Jones Hugh R. A. , Liu Mao-Yuan , Liu Chao
Published: August 2024

In this study, we conducted simulations to find the geometric aberrations expected for images taken by the Main Survey Camera of the Chinese Space Station Telescope (CSST) due to its motion. As anticipated by previous work, our findings indicate that the geometric distortion of light impacts the focal plane's apparent scale, with a more pronounced influence as the size of the focal plane increases. Our models suggest that the effect consistently influences the pixel scale in both the vertical and parallel directions. The apparent scale variation follows a sinusoidal distribution throughout one orbital period. Simulations reveal that the effect is particularly pronounced in the center of the Galaxy and gradually diminishes along the direction of ecliptic latitude. At low ecliptic latitudes, the total aberration leads to about a 0.94 pixel offset (a 20 minute exposure) and a 0.26 pixel offset (a 300 s exposure) at the edge of the field of view. Appropriate processings for the geometric effect during the CSST pre- and post-observation phases are presented.
Research on security protection strategies for household distributed photovoltaic clusters
Authors: Meng Xu , Baofeng Li , Yu Qin , Bin Xu
Published: August 2024

As of the end of March 2023, the cumulative grid-connected capacity of distributed photovoltaics in China was 176.32 GW. In the first quarter of 2023, the new added capacity of it amounted to 18.13 GW. Among them, the addition of grid-connected household-scale photovoltaic capacity was 8.92 GW. The installed capacity and grid-connected capacity continue to maintain a rapid growth trend, with characteristics such as small capacity, large quantity, large load fluctuation, multiple grid-connected points, and difficulty in adjustment. Access to distributed devices on the massive user side cannot be achieved through traditional authentication methods due to their limited resources. Besides, when conducting group dispatching and control for distributed photovoltaic clusters, it is necessary to encrypt and protect the parameters and control command data of group equipment. In response to the above issues, this article studies and proposes a security protection strategy for household distributed photovoltaic clusters. On resource-limited photovoltaic end devices, lightweight authentication of photovoltaic end devices is achieved through a security communication connector embedded with a security module in a software-hardware integrated mode. Then, a photovoltaic cluster data encryption strategy was designed to achieve encrypted transmission of group data, such as parameters and control instructions between intelligent fusion terminals and photovoltaic end devices.
Thermodynamic performance analysis of a coupled system of solar energy and AA-CAES
Authors: Zheng Zhimei , Chen Guang , Xie Ningning , Cui Sen , Zhong Shengyuan , Mei Shengwei , Zhong Geyu
Published: August 2024

Advanced Adiabatic Compressed Air Energy Storage (AA-CAES) is a new large-scale physical energy storage technology that can not only further solve the problem of peak shaving and pressure regulation but also has the advantages of high efficiency, clean zero emissions, integration with renewable energy, and great development space. The article first establishes a thermodynamic model for the compression, heat exchange, expansion, heat storage, and throttle valve of the AA-CAES system, and uses air, nitrogen, and oxygen as storage media to study the impact of non-ideal gas properties on system efficiency, further improving system accuracy. The simulation results show that the system has good performance, with a designed charging and discharging efficiency of 67.7%. In order to further improve efficiency, this paper designs a solar thermal storage and Advanced Adiabatic Compressed Air Energy Storage coupling system (AA-CAES+CSP) and simulates its thermodynamic performance and variable operating conditions. The final system’s electrical-to-electrical conversion efficiency reaches 78.22%.
Solar tracking cycle charger system based on IPSO-DE
Authors: Chen Sirui
Published: August 2024

Aiming to address the problem of resource waste in the photovoltaic industry chain, a solar tracking cycle charger based on IPSO-DE has been designed. The device converts solar energy into electricity through solar photovoltaic panels and stores it in a storage battery. The light-sensitive sensor controls the orientation of the solar panel through a stepper motor according to the position of the Sun, and the single-chip microcomputer is used to control the cyclic charging and discharging of multiple storage batteries. In addition, the charging-discharging voltages at both ends of the battery and the internal temperature of the device are collected and uploaded to the computer terminal. In order to monitor the working status and working environment of the battery in real-time. Meanwhile, the situation of a single battery working for a long time and over-charging or over-discharging will not happen. This prolongs the life of the battery to a certain extent. The maximum power point tracking system based on the IPSO-DE algorithm, short circuit protection circuit, DC-DC circuit, and other modules are also added to improve the solar energy conversion efficiency and refine the load capacity and the solar energy utilization rate.
Capacity optimization of shared energy storage for renewable energy stations considering frequency regulation constraints
Authors: Yang Chang , Li Xiaozhu , Ma Lei , Di Yanqiang , Chen Laijun
Published: August 2024

A sizing method for minimized cost is proposed to optimize the capacity configuration of centralized shared energy storage in new energy-gathering areas. The energy storage system can respond to the Secondary Frequency Regulation (SFR) of the power grid while assuming Primary Frequency Regulation (PFR) obligations. The study generated output and frequency from historical data and established a mixed integer linear optimization configuration model that conforms to PFR and SFR. The results of simulation analysis show that the proposed method meets the Frequency Regulation (FR) requirements of 95.7%. Compared to the self-allocated energy storage, the cost is reduced by 1.4%. The configuration size meets the energy storage grid connection standard, and it can reduce costs and achieve better economic benefits.
Combustion performance optimization of marine diesel-natural gas dual-fuel engines under low operation loads
Authors: Ding Yu , Farrugia Mario , Peng Yang , Xiang La , Scerri Kenneth
Published: August 2024

With the increasingly stringent IMO emission regulations, the diesel-natural gas dual-fuel engine is gradually applied to ship’s power systems. However, the misfire and unconventional emissions of dual-fuel engines under low operation loads limit its application. In this study, a marine diesel/natural gas dual-fuel engine was used as a prototype to develop a 3D CFD simulation model using CONVERGE, which was then validated by using the experimental data under different operation loads. The validated model was used to study the effect of injection timing, intake temperature, and EGR rate on the combustion and emission characteristics under low operation loads soon afterward. The effects of different operating parameters on engine performance and emissions were determined by observing the formation of combustion intermediates and in-cylinder temperature variation. Results show that under small load conditions, advancing diesel injection timing and increasing intake temperature can reduce the emissions of HC and CO while improving the misfire phenomenon partly, but NOx increases. A larger EGR rate can effectively reduce NOx emissions but cause an increase in unconventional emissions. After optimization, the effective power increased by 5.9%, while the HC and CO emissions decreased by 33.1% and 35.2%, respectively. The misfire phenomenon under low operation loads has been significantly improved, thus providing theoretical support for the de sign and operation of dual-fuel engines.
Effect of refueling parameters on state of charge and temperature rise of hydrogen cylinders undergoing fast-filling
Authors: Li Cang , zhang Juyin , Wang Xueping , Zhang Yixiao , Jin Shufeng
Published: August 2024

High-pressure gaseous hydrogen cylinders have been the mainstream onboard storage technology for hydrogen energy vehicles because they offer the benefits of high energy storage density while maintaining low cost. However, the temperature inside the carbon fiber composite cylinders will rise sharply during the hydrogen charging process because of the throttling effect, which affects the mechanical properties of the composites and leads to an insufficient state of charge (SOC) and other problems. This work presents the establishment of a numerical model that describes the rapid filling progress of 35 MPa hydrogen storage cylinders. Important evaluation criteria of the cylinder, namely the state of charge (SOC) and temperature rise, have been analyzed in relation to the filling rate and other parameters using the computational fluid dynamics (CFD) method and thermodynamic analysis methods. The theoretical analysis results, which are consistent with the outcomes of the CFD simulation and experimental analysis, offer the theoretical foundation for the controlling strategy of the filling rate of the gas source from refueling stations and hydrogen temperature. This consequently lowers the energy demand for hydrogen refueling stations to invest in hydrogen pre-cooling.
Research on the optimal allocation of regionally integrated energy systems including multiple energy storage
Authors: Yang Zhenrui , Dou Zhenlan , Sun Chen , Zhang Chunyan , Jiang Kuan , Cai Bin , Zhou Xin , Zhang Baihan
Published: August 2024

The current rapid development of renewable energies, represented by wind energy, poses an enormous challenge for the planning and configuration of integrated energy systems. In this article, a method for optimal allocation of integrated district energy system considering multiple energy storage is proposed, an optimization model of the configuration of the integrated energy system is established to minimize the cost of the integrated system, and the model is solved by using the HJ-PSO optimization algorithm to obtain the optimal energy configuration of the system. The results show that integrated energy systems with multiple energy storage equipment can effectively meet energy demand and the total economic cost of the system can be reduced by 10.4% compared with integrated power systems without energy storage devices, thus achieving better economic and environmental benefits.
Matching maximum power point of gaas solar cells for a photo-rechargeable system with >26% overall efficiency
Authors: Li Shuning , Gao Kun , Qu Ao , Zhu Wei , Zhang Zhipan
Published: August 2024

The rapid development of the Internet of Things and portable/wearable electronic devices has posed increasing demands for handy and efficient off-grid powers. Solar self-powered systems are one of the emerging options, yet their performance is generally not satisfactory. Herein, a rationally designed photo-rechargeable system is constructed by combining highly efficient GaAs solar cells with an array of aqueous Zn-I2 microbatteries (MBs). Through judiciously matching the charging platform of MBs with the maximum power point (MPP) of GaAs solar cells via circuit designs, an unprecedented overall conversion efficiency (η
overall) of 26.32% has been achieved. As a proof of concept, the photo-rechargeable system discharges for 1389 seconds in darkness after 1-minute charging under AM 1.5 G, underscoring its potential for the energy supply of future smart devices.
Research on multi-time scale cooperative optimal scheduling of source, load, and storage in microgrid with flexible resources
Authors: Zhu Cong , Wen Maolin , Lei Yuliang , Xu Gang , Yu Minqi , Lu Xinyao
Published: August 2024

The large-scale integration of wind power and photovoltaics (PV) has increased the uncertainty in power system operation, posing challenges to energy balance. To enhance the flexibility and renewable energy integration capability of the new power system, a multi-timescale coordinated optimization method for microgrid generation-load-storage considering flexibility resource regulation potential is proposed. Based on the regulation potential of demand-side flexibility resources, their multi-timescale characteristics are utilized for operation and regulation. Simulation results confirm that the model can enhance the integration capability of renewable energy, smooth the load curve, and reduce system operating costs.
Collaborative optimization and scheduling of source, load and storage of distribution networks considering distributed energy and load uncertainty
Authors: Zhang Shuo , Chen Shuhao , Lin Fei , Zhao Xin , Li Ganlin
Published: August 2024

Because distributed energy is affected by natural environmental influences, its power output has certain uncertainties, and it is challenging to achieve effective scheduling after it is incorporated into the distribution network. Based on this, a collaborative optimization scheduling strategy for the distribution network source storage load and distribution network is proposed. The scheduling strategy fully considers the randomness of the output of the distributed power supply and the uncertainty of the load demand, builds a target model to minimize the operating cost of the distribution network, uses the slime mold optimization algorithm to solve it, and finally verifies it based on actual cases. The results show that the predicted values of distributed power supplies and energy storage devices can be obtained, proving the accuracy of the proposed model and the proposed algorithm, and providing reference value for the collaborative optimization of actual source-load storage.
Optimization of multi-element energy storage layout and zoning in oilfield power grid under high ratio distributed power source access
Authors: Sun Yun , Li Hualong , Jiang Yafeng , Tan Bin
Published: August 2024

Distributed power generation is a small-scale power generation system, which is distributed in an oil field power grid. In order to improve the poor effect of weak voltage nodes, a new partition optimization method of multi-energy storage layout in the oilfield power grid is proposed by introducing a high proportion of distributed power supply access. The investment and construction cost, the cumulative life cycle discharge loss cost, the operating income and the market income of electric energy are mined, and the model is constructed based on the mining results. The output results are input into the economic benefit maximization function to obtain the constraint conditions of the basic optimization objective function. Based on the constraints, the objective function of multi-energy storage system optimization is constructed, and the function is solved by a differential evolution algorithm to realize the partition optimization of multi-energy storage layout in an oil field power grid. Through experiments, it can be seen that the operation performance of the oil field power grid has been significantly improved through partition optimization of multi-energy storage layout under the condition of a high proportion of distributed power supply access. The experimental results show that the voltage fluctuation of the distributed power supply is small and that the self-absorption rate of photovoltaic power is high.
A self-powered, portable disinfection system based on a triboelectric nanogenerator
Authors: Li Ming , Jiang Tianyi , Liu Shuofu , Sun Haoxiu , Zhang Shanguo , Wu Hao , Wu Wenlong , Li Yu , Jiang Hongyuan
Published: August 2024

Infectious diseases caused by bacteria in air and drinking water have resulted in a huge threat to human health. Here, a self-powered, portable disinfection system based on a triboelectric nanogenerator (TENG) is proposed for air and drinking water. In the system, a UV lamp can be directly powered by TENG due to the high voltage of up to 2500 V and then emits UV rays to break the DNA nucleic acid chains. The output of TENG and the effects of designed parameters on the irradiance are studied systematically. Finally, the disinfection performance for air and drinking water is studied through the system prototype experiments and the results demonstrate that the time needed for complete disinfection (> 6-log) of air and drinking water is 7 min and 11 min. Overall, the proposed system independent of the power grid reveals an excellent disinfection performance and is a potential technology for alleviating air and drinking water safety issues.
Study on lightning overvoltage of mixed collection line in wind farm
Authors: Huang Yu
Published: August 2024

Lightning strikes are a major problem wind power plants face during thunderstorm season. The frequent lightning trips of the collector line, much equipment damage, and high power loss bring great hidden dangers to the safe operation of the wind farm. Combined with the current situation of a wind farm in the Duolei area, western Sichuan, this paper carried out lightning strike overvoltage simulation analysis on the hybrid collector line based on ATP-EMTP, respectively discussed the characteristics of lightning strike overvoltage of the collector line and the collector line under the lightning strike tower and carried out in-depth analysis on the weak lightning protection of the hybrid collector line. The corresponding protection suggestions for different types of lightning strikes have been put forward.
A new AC/DC converter with three-bus output and controllable DC link short-circuit current
Authors: Jiang Runhui , Wu Weimin
Published: August 2024

In the AC/DC hybrid microgrid, single-phase AC/DC converters play a vital role in maintaining the energy balance of the AC grid and DC grid. The industry usually uses large electrolytic capacitors to absorb the secondary ripple power. However, it produces a larger short-circuit current. This paper proposes a three-bus output AC/DC converter that can limit the short-circuit current. The feasibility of steady-state operation and the ability of transient processes to limit short-circuit current was verified.
Study on preparation and performance of cable trench fire separation material for converter station (transforming station)
Authors: Wang Yin , Wang Yu , Yang Dedong , Fu Guanggang , Zheng Chong , Kong Fanfang , Nie Jingkai , Han Yu , Ji Jun
Published: August 2024

Cable trenches and oil-filled equipment areas are prone to electric fires, damaging the power equipment. Fire separation is an effective method to prevent the spread of cable fire and reduce the damage to the power grid. In this paper, the high-temperature resistance and fire safety of new low-carbon inorganic building materials used in transforming stations is tested and evaluated. It is found that the fire separation of floating bead composite geopolymer can meet the requirement that the duration of fire resistance is not less than 3 hours with an electric fire heating curve used in the substation fire protection improvement project. The pore structure characterization and thermogravimetric analysis indicate that the fire-resistive mechanism of the material is that the decomposition of a large amount of dehydrated ettringite at high temperature is the main reason for reducing the unexposed surface temperature rise of the material.
Simulation calculation of the cooling process of phase change cold storage devices in rail vehicles under natural convection conditions
Authors: Liu Chao , Li Mengmeng , Wang Hongyu , Tan Xinhuan , Zhang Lichun
Published: August 2024

Through simulation calculations, the cooling process of the phase change cold storage device in the carriage of rail vehicles under natural convection conditions was analyzed. The total cooling capacity and cooling time of the round tubes were obtained. Based on the calculation results, it was concluded that round tubes are suitable for use as phase change cold storage devices in emergencies inside the carriage under natural convection conditions. A preliminary structural design for the device was proposed, and the feasibility of the device was analyzed through a comparison of different surface convective heat transfer coefficients.
Design and research of energy recovery devices for new energy vehicles
Authors: Long Shihuag , Wu Bo , Cui Longhui , Zhang Wei , Li Yuan , Hu Weijun
Published: August 2024

China is a large automobile consumer. With the continuous progress of science and technology, a variety of new energy vehicles have emerged, and the endurance problem of new energy vehicles has become more and more prominent. In this paper, a new energy vehicle energy recovery device is designed and studied, which makes full use of the inertia of the power battery when the car is running, recovers its energy, converts the kinetic energy of the power battery into electric energy, and transmits the energy to the power battery. In the process of energy recovery, an energy storage device is designed to fully improve the efficiency of energy recovery. It can increase the endurance capacity of new energy vehicles to 25%. The design can be widely used, such as household new energy cars, SUVs, large and medium-sized buses, etc. The design and promotion will certainly pave the way for the popularization and development of electric vehicles.
Development and application of distribution network multi-state management and control system
Authors: Zhang Xiaoyan , Fu Ming , Liang Jiaben , Zhao Jingtao
Published: August 2024

Aiming at the complex and changeable operating state of the new distribution network, flexible aggregation of distributed resources and intricate topology structure, this paper studies the new distribution network management and control methods of three states, including operating state, alert state and fault state, proposes a collaborative control strategy of energy complementarity optimization, and develops a multi-state control system of distribution network. The intelligent management and control mode under “operating status-alert state-fault state” of the distribution network is proposed, which can improve multi-regional energy utilization and power supply reliability in different operating states.
FVM-CFD coupled method for 3d hydraulic simulation on a long-corridor air cushion surge chamber in hydropower plant
Authors: Tian Hua , Liu Daohua , Chen Qianxun , Xia Yong , Liu Yue , Fang Haoyu , Lu Jianwei , Liu Deyou , Zhou Ling
Published: August 2024

A 1D-3D coupled model combining Finite Volume Method (FVM) and 3D Computational Fluid Dynamics (CFD) is firstly developed to investigate 3D dynamic flow regime of air chamber and the influence of different corridor lengths and widths on the 3D transverse unsteady flow in the chamber, which are rarely explored, in particular under the high driving pressure conditions of hydropower plants. The FVM and CFD are separately used for the pipeline section and the air cushion surge chamber, while real-time computation data is exchanged at the FVM-CFD coupled interface. Moreover, the effect of unsteady friction was considered in the water hammer simulations. Experimental results demonstrate that the FVM-CFD coupled method can accurately reproduce the experimental data. Based on the local 3D simulations for different size air chambers, a common feature is observed that spouting geyser arises near the inlet of air chamber during the load rejection initial stage. Results show that when the chamber corridor is longer and narrower under stable conditions and constant gas volume, the peak pressure would be higher and the water level fluctuation becomes more significant, while the wave shape is more regular and the surging period along the chamber long direction is longer. Meanwhile, the water level change exhibits a certain hysteresis in the “spouting geyser area” where the water level fluctuation is minimal and the surging phenomenon occurs less frequently. The reversed results can be observed when the chamber is shorter and wider, the water level fluctuation is more chaotic and the wave shape is more irregular, while the period of surging along the chamber direction is shorter. The water level change in the “spouting geyser area” is more violent, while the water level fluctuation at the chamber inlet is greater and the frequency of surging phenomenon is higher, and the water level fluctuation curves are more regular and smoother. The fluctuation law of the average temperature and the lowest temperature of the chamber water surface are consistent with the pressure fluctuation law. Importantly, the low temperatures (below zero) are possible if the air chamber corridor is too narrow or too short.
Research on heat dissipation performance of electric vehicle brake disc based on multi-field coupling
Authors: Sun Xiao , Ling He , Han Jinliang , Zou Lin
Published: August 2024

The thermodynamic research method of brake discs based on fluid-thermosolid multi-field coupling has a certain relationship with ventilation conditions. To study the influence of semi-closed wheels of electric vehicles on the heat dissipation performance of automobile ventilation discs, the fluid-heat-solid coupling method was adopted, and the coupling platform of ANSYS system was used to realize the complete coupling operation of transient fluid-heat-solid, and the heat dissipation process of ventilation disc of electric vehicles with semi-closed wheels was analyzed under emergency braking conditions. The temperature distribution, flow field characteristics, and stress distribution of brake discs under two different ventilation modes were compared, and the changing rules and distribution characteristics of temperature, flow field, and stress were summarized. Compared with normal ventilation conditions, the calculated values of transient temperature and stress at the corresponding part of the ventilated brake disc increased significantly under weak ventilation conditions.
Multi-objective optimization design for the carcass of marine flexible pipes based on BP neural network and genetic algorithm
Authors: Liao Shuting , Sun Li , Wang Hongfu , Zhang Mingyu
Published: August 2024

The collapse of the carcass is a prominent failure mode in marine flexible pipes. This paper explores the multi-objective optimization design of the carcass layer, focusing on pivotal design variables such as the thickness of the steel strip and the height-thickness ratio of the profile. The objective functions encompass the unit length weight and critical collapse value. The optimization process integrates the BP neural network with the Non-dominated Sorting Genetic Algorithm-II (NSGA-II). Furthermore, the improved minimum distance selection method is applied to extract optimal results from the Pareto front. The insights obtained from this paper hold significant potential to contribute to engineering applications, particularly in advancing the design methodologies for carcass collapse resistance.
Design of grating encoder displacement measurement system
Authors: Lin Yanqing , Ji Chong , Zhang Haiyang , Yang Jiaxu
Published: August 2024

In this paper, by combining TMS320F28335DSP and the grating encoder, the 4× frequency count of the grating encoder displacement measurement is realized, which improves the accuracy of the displacement measurement. Moreover, the human-computer interaction with the developed host computer is carried out through RS232 serial communication to display the displacement. At the same time, the system realizes the positive and negative rotation of displacement measurement by judging the increase and decrease of the pulse signal. Specifically, firstly, two pulse signals output by the grating encoder are preprocessed, and the analog signal is converted to the digital signal. The DSP microprocessor is used for pulse counting, direction recognition, and displacement correlation calculation, and the human-computer interaction is carried out through serial communication. The experimental results show that the method has stable data transmission, accurate measurement value, and improved accuracy of encoder displacement measurement.
Affordance-based performance scale-up associated with structural parameters for product design
Authors: Gao Xiangyu , Zhang Shuyou , Qiu Lemiao , Cheng Changlong , Wang Yang , Zhang Peng
Published: August 2024

Product scale-up design is critical in developing many of today’s products. The traditional scale-up design methods (TSDM) use an analytical approach or empirical similarity method, which may not meet the requirement of dimensionless parameters when designing complex products. We develop an affordance-based scale-up method for the complex product design. Requirements-performance and performance-structure affordance constraints are constructed to connect the requirements and the structure parts. Then, the main parts are extracted based on the affordance matrix, and the coupling matrix is constructed. Analyzing the structural characteristic model, the parameters are extracted for the three matrices used for the parameters design. Take an injection molding machine as an example, and the example demonstrates the feasibility and potential industrial impact on product development.
Optimized design of high-resolution zero encoding for digital micrometers
Authors: Ye Guoyong , Zhang Yong , Sun Qianxiao , Xiao Zhenyu
Published: August 2024

Precision digital micrometers are promising sensors for micro-displacement measurements in precision manufacturing and metrology instruments. In this paper, the structure of the digital micrometer and the grating zero generation are optimized and designed. Firstly, the zero grating is modeled by introducing the basic principles of the digital micrometer. Then the constraints of the optimization process are defined. Finally, MATLAB simulations are performed. The results show that the designed high-resolution reference signal precision digital micrometer meets the theoretical requirements and is very suitable for application in precision measurement.
Design and optimization of planetary wheel systems for formula racing cars
Authors: Sun Yirui , Bing Xinyu
Published: August 2024

Based on the transmission system of the electric formula racing car, this article introduces the design of a new NW planetary gear train and the simulation ideas of the entire system. This study greatly ensures the accuracy of the analysis results by outputting the transmission power of the entire system and then using software to accurately select multiple parameters of each pair of gears. Further research was conducted on tooth direction modification to find the most accurate modification scheme suitable for the planetary gear train. This method has been applied to the Chinese Student Electric Formula E02 racing car, achieving the fastest speed and best stability in many competitions.
Zinc coating and its application in radar
Authors: Liang Yuanjun
Published: August 2024

This paper introduces the common types of zinc coating, corrosion mechanism, application precautions, and key points of zinc coatings in radar anti-corrosion according to the characteristics of radar structure components, including hot-dip galvanizing, thermal spraying zinc, electroplated zinc, powder zinc infiltration, zinc-chromium coating, and zinc coating.
Influence of new wire structure on AC loss of high-temperature superconducting cables
Authors: Ma Minghao , Ma Yonghu
Published: August 2024

The different structures of wire in high-temperature superconductors (HTS) can affect the magnetic field distribution of the tapes, thereby influencing the AC losses of the tapes. In this paper, a cylindrical HTS cable model of different HTS tapes was established using the finite element analysis software COMSOL Multiphysics, and the AC losses of different superconducting cables were calculated based on the H equation. Through data collection and result analysis, the effectiveness, accuracy, and rationality of the simulation calculations were verified.
Multiferroic properties of NiFe2O4-Ba0.7Ca0.3TiO3 nanocomposites
Authors: Giang Tran Thi Ha , Thi Viet Chinh Nguyen , Lam Dao Son , Linh Dinh Chi , Nam Pham Hong , Bach Ta Ngoc , Long Nguyen The , Manh Do Hung , Dung Dang Duc , Toan Huynh Ngoc , Poddubnaya N N , Thanh Tran Dang
Published: August 2024

In this report, we present results on the multiferroic properties of four nanocomposite samples of NiFe2O4-Ba0.7Ca0.3TiO3 (NFO/BCTO), which were fabricated through combinations of high-energy ball milling, heat treatment, and spark plasma sintering techniques. Structural analyses revealed that these samples simultaneously contain two phases of nano-sized NiFe2O4 (NFO) and Ba0.7Ca0.3TiO3 (BCTO) crystals. The addition of NFO into the BCTO-host did not alter the crystal structure but significantly improved the multiferroic characteristics compared to pure BCTO. Furthermore, variations in saturation magnetization (M
s) and coercivity (H
c) were investigated as a function of temperature. The results showed that Ms increased gradually with the concentration of NFO. In terms of temperature dependence, M
s(T) data deviated from the Bloch’s law with an exponent coefficient α changing in the range of 1.8–1.9, decreasing gradually as the NFO concentration increased. Meanwhile, H
c decreased gradually as the NFO concentration increased and followed the Kneller’s law in terms of temperature dependence.
Development of a text mining algorithm for identifying adverse drug reactions in electronic health records
Authors: van de Burgt Britt W M , Wasylewicz Arthur T M , Dullemond Bjorn , Jessurun Naomi T , Grouls Rene J E , Bouwman R Arthur , Korsten Erik H M , Egberts Toine C G
Published: August 2024

Objective

Adverse drug reactions (ADRs) are a significant healthcare concern. They are often documented as free text in electronic health records (EHRs), making them challenging to use in clinical decision support systems (CDSS). The study aimed to develop a text mining algorithm to identify ADRs in free text of Dutch EHRs.

Materials and Methods

In Phase I, our previously developed CDSS algorithm was recoded and improved upon with the same relatively large dataset of 35 000 notes (Step A), using R to identify possible ADRs with Medical Dictionary for Regulatory Activities (MedDRA) terms and the related Systematized Nomenclature of Medicine Clinical Terms (SNOMED-CT) (Step B). In Phase II, 6 existing text-mining R-scripts were used to detect and present unique ADRs, and positive predictive value (PPV) and sensitivity were observed.

Results

In Phase IA, the recoded algorithm performed better than the previously developed CDSS algorithm, resulting in a PPV of 13% and a sensitivity of 93%. For The sensitivity for serious ADRs was 95%. The algorithm identified 58 additional possible ADRs. In Phase IB, the algorithm achieved a PPV of 10%, a sensitivity of 86%, and an F-measure of 0.18. In Phase II, four R-scripts enhanced the sensitivity and PPV of the algorithm, resulting in a PPV of 70%, a sensitivity of 73%, an F-measure of 0.71, and a 63% sensitivity for serious ADRs.

Discussion and Conclusion

The recoded Dutch algorithm effectively identifies ADRs from free-text Dutch EHRs using R-scripts and MedDRA/SNOMED-CT. The study details its limitations, highlighting the algorithm's potential and significant improvements.
Long non-coding RNAs involved in Drosophila development and regeneration
Authors: Camilleri-Robles Carlos , Amador Raziel , Tiebe Marcel , Teleman Aurelio A , Serras Florenci , Guigó Roderic , Corominas Montserrat
Published: August 2024

The discovery of functional long non-coding RNAs (lncRNAs) changed their initial concept as transcriptional noise. LncRNAs have been identified as regulators of multiple biological processes, including chromatin structure, gene expression, splicing, mRNA degradation, and translation. However, functional studies of lncRNAs are hindered by the usual lack of phenotypes upon deletion or inhibition. Here, we used Drosophila imaginal discs as a model system to identify lncRNAs involved in development and regeneration. We examined a subset of lncRNAs expressed in the wing, leg, and eye disc development. Additionally, we analyzed transcriptomic data from regenerating wing discs to profile the expression pattern of lncRNAs during tissue repair. We focused on the lncRNA CR40469, which is upregulated during regeneration. We generated CR40469 mutant flies that developed normally but showed impaired wing regeneration upon cell death induction. The ability of these mutants to regenerate was restored by the ectopic expression of CR40469. Furthermore, we found that the lncRNA CR34335 has a high degree of sequence similarity with CR40469 and can partially compensate for its function during regeneration in the absence of CR40469. Our findings point to a potential role of the lncRNA CR40469 in trans during the response to damage in the wing imaginal disc.
Associations between per- and polyfluoroalkyl substance exposures and metabolic dysfunction associated steatotic liver disease (MASLD) in adult National Health and Nutrition Examination Survey 2017 to 2018
Authors: Samala Niharika , Kulkarni Manjiri , Lele Rachana S , Gripshover Tyler C , Lynn Wise Jaime , Rai Shesh N , Cave Matthew C
Published: August 2024

Per- and polyfluoroalkyl substances (PFAS) are persistent organic pollutants previously associated with elevated liver enzymes in human cohorts and steatotic liver disease in animal models. We aimed to evaluate the associations between PFAS exposures, and liver enzymes and vibration controlled transient elastography (VCTE) biomarkers of metabolic dysfunction associated steatotic liver disease (MASLD) in adult National Health and Nutrition Examination Survey (NHANES) 2017 to 2018. VCTE was determined by FibroScan. Serum PFAS (n = 14), measured by mass spectrometry, were analyzed individually and by principal component (PC). Univariate and multivariable associations were determined between PFAS exposures and liver disease outcome variables: alanine aminotransferase (ALT), controlled attenuation parameter (CAP), liver stiffness measurement (LSM), FibroScan-based Score (FAST), using R. About 1,400 participants including 50% women with a mean age of 48 ± 19 years and a mean BMI of 29 ± 7 kg/m2 were analyzed. Four PFAS clustered to PC1, whereas 3 PFAS clustered to PC2. PC1 was significantly associated with ALT (β = 0.028), CAP (β = 0.041), LSM (β = 0.025), and FAST (β = 0.198) in univariate analysis. Individual PFAS exposures were oftentimes inversely associated with these measurements in multivariate analysis. In adult NHANES 2017–2018, PFAS may not be a significant burden for MASLD, because of the inconsistent associations between the environmental PFAS exposures and biomarkers of liver steatosis, inflammation, and fibrosis. More data are required to better understand the relationships between PFAS exposures and liver disease.
A Brief Intervention on Alcohol Use Disorder Is Associated With Treatment Access for Inpatients With Alcohol-associated Liver Disease
Authors: Twohig Patrick A. , Balasanova Alena , Cooper Lauren , Le Michelle , Khoury Nathalie , Manatsathit Wuittporn , Olivera Marco , Peeraphatdit Thoetchai Bee
Published: August 2024

Background

Alcohol-associated liver disease (ALD) is the most common indication for liver transplantation in the United States. Alcohol use disorder (AUD) treatment is recommended in all patients with ALD and AUD, but it remains underutilized.

Aims

To identify predictors of AUD treatment and to assess 30-day readmission, return to drinking, and 1-year transplant-free survival.

Methods

Retrospective single-center cohort study of consecutive patients hospitalized with ALD and AUD between 2018 and 2020. Patients who died or were lost to follow-up at 90 days after hospitalization were excluded. AUD treatment was defined as receiving medication or participating in residential, outpatient, or support groups within 90 days of discharge.

Results

One hundred nine patients were included. Mean age was 51.7 years, and 63% were male. Fifty-six (51%) patients received AUD treatment, and 23 (21%) patients received more than one treatment. Predictors of AUD treatment were younger age (OR, 1.07 [95% CI, 1.04–1.12]; P < 0.001), gastroenterology/hepatology consult (AOR, 8.54 [95% CI, 2.55–39.50]; P = 0.0002), addiction psychiatry consult (AOR, 2.77 [95% CI, 1.16–6.84]; P = 0.02), and a brief AUD intervention (AOR, 18.19 [95% CI, 3.36–339.07]; P = 0.0001). Cirrhosis decompensation, MELD-Na score, and insurance status were not associated with treatment. Thirty-one patients (28.4%) were readmitted, and 29 (26.6%) remained abstinent 30 days from discharge. Patients who received treatment had improved transplant-free survival (HR, 0.44, P = 0.04).

Conclusion

A brief intervention on AUD had the strongest association with receiving AUD treatment in our cohort. Further efforts to incorporate brief interventions when offering AUD treatment to patients with ALD may be beneficial.