bluuebunny/crossref_metadata_2025 huggingface dataset:
Selection homophily and peer influence for adolescents’ smoking and vaping norms and outcomes in high and middle-income settings
Authors: Murray Jennifer M. , Sánchez-Franco Sharon C. , Sarmiento Olga L. , Kimbrough Erik O. , Tate Christopher , Montgomery Shannon C. , Kumar Rajnish , Dunne Laura , Ramalingam Abhijit , Krupka Erin L. , Montes Felipe , Zhou Huiyu , Moore Laurence , Bauld Linda , Llorente Blanca , Kee Frank , Hunter Ruth F.
Published: September 2023

The MECHANISMS study investigates how social norms for adolescent smoking and vaping are transmitted through school friendship networks, and is the first study to use behavioral economics methodology to assess smoking-related social norms. Here, we investigate the effects of selection homophily (the tendency to form friendships with similar peers) and peer influence (a social process whereby an individual’s behavior or attitudes are affected by peers acting as reference points for the individual) on experimentally measured smoking and vaping norms, and other smoking outcomes, in adolescents from high and middle-income settings. Full school year groups in six secondary schools in Northern Ireland (United Kingdom) and six secondary schools in Bogotá (Colombia) participated (n = 1344/1444, participation = 93.1%, target age 12–13 years). Over one semester, pupils received one previously tested school-based smoking prevention program (ASSIST or Dead Cool). Outcomes included experimentally measured smoking/vaping norms, self-report and objectively measured smoking behavior, and self-report smoking norms, intentions, susceptibility, attitudes, and psycho-social antecedents. We investigated selection homophily and peer influence using regressions and SIENA modeling. Regression results demonstrate lagged and contemporaneous selection homophily (odds ratios [ORs] = 0.87–1.26, p ≤ 0.01), and peer influence effects for various outcomes from average responses of friends, school classes, or school year groups (standardized coefficients [βs] = 0.07–0.55, ORs = 1.14–1.31, p ≤ 0.01). SIENA models showed that comparable proportions of smoking/vaping-based similarity between friends were due to selection homophily (32.8%) and peer influence (39.2%). A higher percentage of similarity between friends was due to selection homophily and/or peer influence for ASSIST schools compared to Dead Cool. Selection homophily was also more important in Bogotá, whilst peer influence was stronger in Northern Ireland. These findings support using social norms strategies in adolescent smoking prevention interventions. Future research should consider selection homophily and social influence jointly, and examine whether these findings translate to other high and low-middle-income settings with varying cultures and norms.
A preliminary phylogeny for the pseudoscorpion family Garypinidae (Pseudoscorpiones: Garypinoidea), with new taxa and remarks on the Australasian fauna
Authors: Harvey Mark S.
Published: September 2023

The pseudoscorpion family Garypinidae is globally distributed with 79 species in 21 genera and several species represented by Mesozoic and Eocene fossils. This was recently included with the family Larcidae in a unique superfamily, Garypinoidea but there are no phylogenetic hypotheses for the group. Sequence data were obtained for 14 species in 8 genera and numerous outgroup taxa that formed the basis for a preliminary molecular phylogeny. A new subfamily classification is proposed with Protogarypininae, subfamily nov. comprising five genera mostly found in the southern hemisphere, Amblyolpiinae subfamily nov. comprising two genera and Garypininae for the remaining genera. Several new taxa are described including the first Australian species of Aldabrinus, A. rixi sp. nov., a new genus from South-East Asia, Nobilipinus, comprising Nobilipinus nobilis (With, 1906), N. vachoni (Redikorzev, 1938) (that is removed from the synonymy of G. nobilis) and five new species, N. affinis, N. galeatus, N. karenae, N. kohi and N. tricosus, and Solinus pingrup sp. nov. from south-western Australia. Paraldabrinus Beier, 1966 is newly synonymised with Aldabrinus, and Indogarypinus Murthy and Ananthakrishan, 1977 is newly synonymised with Solinus. The holotype of Garypinus mirabilis With, 1907 from Hawaii is redescribed but found to be a tritonymph, rendering the generic identity uncertain. ZooBank: urn:lsid:zoobank.org:pub:E15E4705-0697-4208-9338-A778343996CA
Technology preparedness and translator training
Authors: Venkatesan Hari
Published: September 2023

With increasing acknowledgment of enhanced quality now achievable by Machine Translation, new possibilities have
emerged through collaboration between human and machine in the translation process, including providing varying qualities of
translation in response to quality/efficiency requirements. This paper presents surveys of post-graduate students of translation
conducted over four consecutive years to examine if their awareness and preparedness have kept pace with these possibilities. It
is found that respondents across the years generally perceive their awareness as lacking, are hesitant in employing MT, and show
marked reservations when reconsidering issues such as quality and the preeminent position of the human translator. A review of
existing research in translator training points towards a lopsided emphasis on linguistic competence and standalone courses for
introducing technology as the primary cause behind low adoption. The need of the hour is translator training that fully integrates
technology in the translation process and also provides a clear framework to adjust quality/efficiency is important to ensure
preparedness. A repeat survey of students from 2021 who were trained under this model shows an increase in willingness to use MT
and to consider quality as dependent on intended use. The focus here is on Chinese-English translation, but the discussion may
find resonance with other language pairs.
Colorimetry-based and smartphone-assisted machine-learning model for quantification of urinary albumin
Authors: Bhatt Sunita , Kumar Sunil , Gupta Mitesh Kumar , Datta Sudip Kumar , Dubey Satish Kumar
Published: September 2023

The presence of albumin in the urine is indicative of kidney damage and can occur due to several underlying conditions, such as diabetes. The concentration of albumin in urine is used for the diagnosis and staging of chronic kidney disease (CKD). In clinical samples, the detection of albumin at lower concentrations is crucial for the early diagnosis and monitoring of CKD. Current urine analyzers precisely quantify albumin but are expensive and difficult to use in point-of-care (PoC) settings. Here, we demonstrate the quantification of albumin concentration in a urine sample using colorimetry. This model presents an accessory-free urine analyzer that uses a smartphone and customized machine-learning algorithms. Here, a urine sample is introduced onto a chemically impregnated dipstick that exhibits a change in color with the amount of albumin. Images of the urine dipsticks are captured using a smartphone camera under different illumination/experimental conditions and are processed to extract changes in the color values arising due to changes in the concentration of urinary albumin. Albumin concentrations are estimated from changes in color values. We used customized machine-learning algorithms to classify albumin concentrations and mitigate the effect of ambient light conditions. The k-nearest neighbor algorithm yielded an average classification accuracy of 96% with a detection limit of 4 mg l−1. The proposed scheme can be extensively used to monitor albumin concentration in PoC settings.
A panoramic image stitching method for nuclear fuel assemblies
Authors: Yang Bin , Cheng Yu-qi , Chen Rui , Li Li , Guo Ran , Geng He-hui , Liu Tao , Li Wen-long
Published: September 2023

The fuel assembly (FA) is the core component of the nuclear reactor, and inaccurate inspection of FA bending and deformation can cause severe disasters in nuclear power plant reactors. It is an important task to restore a panoramic image of the FA from the video collected by the orthogonal visual inspection system. It can provide a more intuitive qualitative observation. Meanwhile, it is conducive to the estimation of deformation. This paper proposes a panoramic image stitching method for nuclear FA, which classifies video frames into grid images (GI) and non-grid images (NGI). It utilizes the speed of GI frames to estimate the speed of NGI frames. The horizontal offset and vertical offset between frames are estimated in two steps. The high-quality panoramic image can be obtained by image fusion. The experimental results indicate that the proposed method can achieve the panoramic image stitching of simulated samples and actual FAs with a deformation estimation accuracy of 0.3 mm. The proposed method has been verified and used in actual nuclear power plant reactor maintenance.
Global existence of solutions to the 4D attraction–repulsion chemotaxis system and applications of Brezis–Merle inequality
Authors: Hosono Tatsuya , Ogawa Takayoshi
Published: September 2023

We consider the Cauchy problem for an attraction–repulsion chemotaxis system in the four space dimension. One of main topics in the study of such a system is the presence of L
1 threshold. In fact, the critical mass phenomenon called 8π-problem is well-known in the two-dimensional setting. In this paper, we show the global existence of solutions to the Cauchy problem for the four-dimensional subcritical case, that is, the total mass of the initial data is less than the four-dimensional L
1 threshold value

(
8
π

)
2

. The key ingredients are the four-dimensional Brezis–Merle type inequality of the 4th-order elliptic equation and some inequalities derived from rearrangement arguments.
A low cost ripple tank experiment with 3D printed components and an Arduino control unit
Authors: Westhoff Peter Michael , Pusch Alexander
Published: September 2023

In this article we present a ripple tank with 3D printed components including a control unit with Arduino microcontroller that can be inexpensively replicated. With the presented setup, experiments such as Huygens’ principle, diffraction, and the double-slit experiment according to Young are possible. Due to the simple operability and the comparatively low price, the experiments can be carried out easily and quickly by the learners themselves.
An improved QFT-based quantum comparator and extended modular arithmetic using one ancilla qubit
Authors: Yuan Yewei , Wang Chao , Wang Bei , Chen Zhao-Yun , Dou Meng-Han , Wu Yu-Chun , Guo Guo-Ping
Published: September 2023

Quantum comparators and modular arithmetic are fundamental in many quantum algorithms. Current research mainly focuses on operations between two quantum states. However, various applications, such as integer factorization, optimization, and financial risk analysis, commonly require one of the inputs to be classical. It requires many ancillary qubits, especially when subsequent computations are involved. In this paper, we propose a quantum–classical comparator based on the quantum Fourier transform. Then we extend it to compare two quantum integers and modular arithmetic. Proposed operators only require up to one ancilla qubit, which is optimal for qubit resources. We analyze limitations in the current modular addition circuit and develop it to process arbitrary quantum states in the entire n-qubit space. The proposed algorithms reduce computing resources and make them valuable for noisy intermediate-scale quantum computers.
Optimal subradiant spin wave exchange in dipole-coupled atomic ring arrays
Authors: Han Yu-xiang , Chen Hao , Liu Wenxiao , Xue Jiao-jiao , Li Hong-rong
Published: September 2023

The subwavelength array of quantum emitters provides an ideal platform for exploring rich many-body dynamics, such as super- and subradiance. In this paper, we explore the dynamics of spin wave exchange between two dipole-coupled atomic ring arrays. Subradiant spin waves lead to low-loss and high efficiency of ring-to-ring transfer. The optimal subradiant spin wave exchange occurs at appropriate separations between coplanar rings, despite the fact that the energy transfer efficiency is monotonically enhanced (in the regime

⩽

λ
0

/

2

) as the rings’ separation decreases. However, the spin wave will scatter due to the dephasing mechanism of close-by atom pairs, as the separation of two rings is too small. With the increase in the number of atoms on the ring, the subradiant shielding effect also strengthens, leading to a shorter distance for the transfer of spin waves. We investigate the rotation of one of the rings and find that the optimal spin wave exchange corresponds to the scenario where the line connecting the two nearest atoms of the two rings aligns with the center of the circle. Moreover, we study the influence of transition dipole moment orientations on the effective interaction between two atomic rings. We observe that there is a critical point where the effective interaction strength changes dramatically owing to the cooperative effect of the subwavelength atomic array. We believe that our results could be important for quantum information processing based on atomic arrays.
Determining Hubbard U of VO2 by the quasi-harmonic approximation
Authors: Kong 孔 Longjuan 龙娟 , Lu 陆 Yuhang 雨航 , Zhuang 庄 Xinying 新莹 , Zhou 周 Zhiyong 志勇 , Hu 胡 Zhenpeng 振芃
Published: September 2023

Vanadium dioxide VO2 is a strongly correlated material that undergoes a metal-to-insulator transition around 340 K. In order to describe the electron correlation effects in VO2, the DFT +U method is commonly employed in calculations. However, the choice of the Hubbard U parameter has been a subject of debate and its value has been reported over a wide range. In this paper, taking focus on the phase transition behavior of VO2, the Hubbard U parameter for vanadium oxide is determined by using the quasi-harmonic approximation (QHA). First-principles calculations demonstrate that the phase transition temperature can be modulated by varying the U values. The phase transition temperature can be well reproduced by the calculations using the Perdew–Burke–Ernzerhof functional combined with the U parameter of 1.5 eV. Additionally, the calculated band structure, insulating or metallic properties, and phonon dispersion with this U value are in line with experimental observations. By employing the QHA to determine the Hubbard U parameter, this study provides valuable insights into the phase transition behavior of VO2. The findings highlight the importance of electron correlation effects in accurately describing the properties of this material. The agreement between the calculated results and experimental observations further validates the chosen U value and supports the use of the DFT + U method in studying VO2.
Majorana noise model and its influence on the power spectrum
Authors: Chen 陈 Shumeng 书梦 , Ding 丁 Sifan 思凡 , Zhang 张 Zhen-Tao 振涛 , Liu 刘 Dong E. 东
Published: September 2023

Majorana quantum computation offers a potential approach to securely manipulating and storing quantum data in a topological manner that may effectively resist the decoherence induced by local noise. However, actual Majorana qubit setups are susceptible to noise. In this study, from a quantum dynamics perspective, we develop a noise model for Majorana qubits that accounts for quasi-particle poisoning and Majorana overlapping with fluctuation. Furthermore, we focus on Majorana parity readout methodologies, specifically those leveraging an ancillary quantum dot, and carry out an in-depth exploration of continuous measurement techniques founded on the quantum jump model of a quantum point contact. Utilizing these methodologies, we proceed to analyze the influence of noise on the afore-mentioned noise model, employing numerical computation to evaluate the power spectrum and frequency curve. In the culmination of our study, we put forward a strategy to benchmark the presence and detailed properties of noise in Majorana qubits.
Towards Blur Mixed Instance Search Combined with Image-wise and Object-wise Feature
Authors: Wang Yang , Zhang Yixing , Ge Hao
Published: September 2023

With development of intelligent robots and autonomous driving, images/videos with motion blurs occur frequently. However, these images/videos with blurs might be retrieved. Instance search has been studied for many years in the computer vision field. However, few works are focused on instance search on blurred images. In this paper, we propose a framework of instance search on blurred image datasets which is built on three components including query blur mixing, image-wise feature based ranking, and instance-wise feature based re-ranking. Due to lack of the benchmark, we also collect and build a blurred image dataset on which we conduct performance experiments. Experimental results show that our solution is significantly promising in instance search task.
DOA Estimation Based on Eigen Space and Toeplitz Processing
Authors: Qin Yi , Chen Xiangyang
Published: September 2023

In order to efficiently and accurately estimate the direction of arrival of coherent signals, a Toeplitz estimation method based on eigen space multiple signal classification (MUSIC) algorithm is proposed. Firstly, the coherent signal is processed by Toeplitz, and then the MUSIC algorithm of the eigen space is used to estimate the DOA accurately. The computer simulation results show that the method can realize the accurate estimation of the angle under the condition of signal coherence, and the accuracy is improved compared with some other algorithms.
Bi-objective Optimization for Multi-depot Green Vehicle Routing problem with Time Windows Considering Carbon Emission
Authors: Shi Yuhe , Lin Yun
Published: September 2023

The issue of carbon emission reduction has attracted extensive attention in academic circles, but there are few studies on the Pareto frontier analysis of the multi-depot green vehicle routing problem with multi-objective. In order to effectively balance economic and environmental effects, this paper constructs a bi-objective optimization model for the open multi-depot green vehicle routing problems with time windows, which takes operating cost and carbon emission as the objective functions. NSGA-III is used to obtain the Pareto solution set of the bi-objective model. The experimental results indicate that the proposed bi-objective optimization model is effective in controlling costs and reducing carbon emissions.
An Approach for Suppressing Fluid Instabilities in Liquid Metal Battery with an Internal Structure
Authors: Li Benwen , Zhu Enqi , Liu Ke , Guo Jingru , Li Chenhao , Feng Encheng
Published: September 2023

The instabilities of fluid in the liquid metal battery (LMB) can easily cause a short circuit and lead to safety accidents, which have become a bottleneck in LMB industrial applications. In this case, a structure named grid-structure (GS) based on the inner cavity of the LMB has been used to suppress the fluid instabilities. Based on OpenFOAM-4 x numerical simulation, we analyzed the critical electric potential in basic structures, which is introduced as the threshold of magnetohydrodynamic (MHD) instabilities. We constructed the GS with a different number of baffles. The simulation results show that the GS can effectively change the spatial distribution of the magnetic field and the flow field. And it can improve the charging/discharging efficiency and enhance the stability of LMB. Simulation results also show that the number of baffles has a positive relationship with the effect of suppressing the instabilities of MHD. This study helps determine the influencing factors of MHD instabilities and proves the universality of the GS.
Performance research of the PVT-coupled water loop heat pump system
Authors: Liu Weitao , Zhang Xunda , Guo Cuishuang , Ai Dengxin , Yin Baoquan
Published: September 2023

Based on one public office building retrofit project in Tianjin, this paper describes the construction of a PVT coupled with a water-to-water heat pump system to test its performance in cold regions. The system’s performance was evaluated under winter conditions, including the temperature changes of the photovoltaic panel and water tank with respect to the irradiation time, the instantaneous power generation of PVT and PV systems, the daily power generation efficiency, the heat collection efficiency of PVT system, and the COP of the system. The results show that under one day’s solar radiation, the mean temperature of the PVT and PV systems can reach 16.1°C, and the PVT power efficiency is 2.2% higher than the PV. The PVT system has a daily average power generation efficiency of about 10.4%, a heat collection efficiency of 42.2%, and a daily power generation of 194.4 kWh. The maximum temperature of the storage water tank reached 46.4°C, and the mean COP for the whole day was 6.86, meeting the actual heating requirements.
Heat Release Simulation Research Based on Solid Heat Storage and Release Materials
Authors: Li Wentao , Jing Yanjun , Li Yuan , Xing Zuoxia , Chen Lei
Published: September 2023

To promote the actual investment of solid electric heat storage heating devices, three different heat storage and heat release materials are used to simulate and analyze the heat release. The results show that “magnesia brick has the best heat storage and release capacity in 10 hours”. In terms of average temperature performance, silica brick is the best, and the standard deviation of temperature reaches the maximum value at 8 h, which is 75.13 k. It is less than the maximum value of 99.70 k for magnesia brick and 114.93 k for solid waste ceramic brick. However, the manufacturing cost of silica brick is the highest, and the cost of solid waste ceramic brick is the lowest. Solid waste ceramic bricks can be preferentially selected under the condition of meeting the requirements of heat storage and release.
Research on Park Energy System Based on Grid Connection of Renewable Energy Power Generation
Authors: Xing Zuoxia , Gai Min , Chen Lei
Published: September 2023

With the maximum consumption of renewable energy, the minimum emission of pollutants and the minimum comprehensive investment cost as the optimization objectives, the operation model of the park’s energy system considering the thermal power balance constraint, natural gas balance constraint and power grid power constraint was proposed, and the scenic power generation and electricity equipment of the park were studied. By comparing different operation scenarios, the influence of adding different equipment on the operation optimization of the whole park under the thermoelectric coupling is comprehensively analyzed. The balance curve of equipment output and related energy use is analyzed on a yearly cycle, indicating that the power supply grid of the park based on the thermoelectric coupling has great reliability and effectiveness in the consumption of renewable energy, and its economy is also significantly improved.
Cloud-edge Collaboration Based Methods in Improving the Safety Inspection Efficiency on Electric Operation Scenes
Authors: Fei Zhengming , Zhou Hui , Wang Kai , Yin Fan
Published: September 2023

The safety in electric operation scenes directly influences social economic development and stability. Safety supervision and inspection is one of the most important links in the electricity generation process. The previous mode of executing supervision and inspection in advance and analyzing and reporting afterwards cannot satisfy the requirements of the modern management system, which requests beforehand prevention, in-process control, post review, and analysis. The supervision and inspection efficiency is low. Therefore, this paper proposed three innovative methods to increase the supervision and inspection efficiency of the electric operation. First, we proposed an operation demonstration method on electric equipment that integrates with Augmented Reality (AR). It can greatly increase the operating accuracy and decrease the probability of accidents. Then, a smart, mobile, and cloud-edge collaborated method is proposed, aiming at increasing the availability and effectiveness of safety supervision and inspection. Last, we adopted technical means of integrative recognition to increase the efficiency of obtaining evidence on inspection.
Operational optimisation of integrated campus energy systems considering integrated demand response
Authors: Li Lijiao , Li Mengda , Li Zhiquan , Li Shuyi
Published: September 2023

Against the backdrop of the rapid development of the energy internet in the park, the multi energy coupling and complementary characteristics of integrated energy systems provide more space for optimizing the participation of demand parties in their coordinated planning. Establishing a effective demand side model with multiple energy flows and response types has become an effective means to improve system performance. For this reason, this paper takes the comprehensive energy system of the park with multiple electricity, gas, heat and cold complements as the research object, establishes a complete model of multi load and multi type demand response based on the improvement, incentive and substitution of real-time pricing mechanism, and uses multi-attribute decision-making method to obtain the optimal configuration of the system by establishing an optimization framework for iteration of the main problem and sub problem. The simulation results show that compared with traditional energy supply system configurations, the complete model established in this paper for various controllable resources on the demand side achieves the coordinated and complementary operation of the system’s multi energy and low-carbon economy, fully utilizing the regulatory potential of the demand side, effectively reducing load fluctuations and energy supply costs.
The Optimal Energy Flow Strategy of Integrated Energy System Considering Demand Response
Authors: Bai Hong , Cai Yinong , Guan Yan , Liu Shuo
Published: September 2023

Building an integrated energy system with source-load coordination and flexible interaction in the context of dual carbon is an effective path to building a new type of power system. The efficient operation of the integrated energy system can be promoted by establishing incentives such as energy subsidies to reasonably regulate the demand response on the customer side. In this paper, we consider the multi-source demand response on the customer side and study the optimal energy strategy from the perspective of the Integrated Energy Service Company (IESC), specifically involving the construction of the system electricity demand response and heat demand response models. And we propose an IESC optimal energy flow considering the customer’s demand and supply balance game to optimize the IESC. The optimal energy flow strategy of IESC considering the demand response of users is proposed. Finally, the correctness and rationality of the model are verified by simulation analysis.
Research on power management circuit of magnetic field energy harvesting for wireless sensor
Authors: Liu Peng , Chen Zhongbin , Li Wei
Published: September 2023

In order to solve the power supply problem of wireless sensors in the power cable environment, the changing magnetic field around the cable is used, and the open energy harvesting coil and power management circuit are used to supply power to the sensor. However, improving circuit applicability and output efficiency is the key. For this reason, through the circuit principle and simulation analysis, the basic model of the power management circuit is established, and the overvoltage protection and energy storage unit are designed for the special environment of the cable to solve the problem of circuit protection and energy supply dead zone. Then reduce the circuit loss according to the circuit topology design. Finally, an experimental platform is built to verify the output effect of the power management circuit. The voltage induced by the magnetic induction power acquisition module can obtain a stable and reliable output voltage through the power management circuit, which can realize the self-sufficiency of the power supply of the wireless sensor.
Research on Step-down Resonance Suppression and Filtering Device
Authors: Liu Shaojie , Zhao Yingying , Lu Jian , Ye Jifang
Published: September 2023

In recent years, offshore wind farms have developed rapidly, and their installed capacity is getting bigger and bigger, and the offshore distance is getting farther and farther. In order to meet the needs of large-capacity and long-distance offshore wind power transmission, the AC submarine cable has the characteristics of long distance, high voltage and large cross-section. Along with the significantly improved transmission capacity, its equivalent capacitance is also increasing, which further reduces the resonance frequency of the offshore wind power AC transmission system. If the parallel resonance frequency of the offshore wind power transmission system is close to the main harmonic current frequency band of wind turbines, it will cause harmful system resonance and harmonic amplification, significantly increasing the harmonic current of grid-connected lines and the voltage distortion rate of nodes in nearby power grids, and seriously affect the safety of equipment and the safe and stable operation of offshore wind power transmission system. A step-down resonance suppression filtering device applied to the offshore wind power transmission system is proposed. The AC cable is connected to the low-voltage 35 kV side of the compensation winding of the centralized control center to eliminate the resonance risk of the 220 kV system and filter out the harmonic current. Compared with the existing technical scheme, the device has the advantages of simple control, reliable operation, stable resonance suppression effect, low operation loss and the like, and has great engineering popularization value.
Experimental Study on High-Temperature Cycling Aging of Large-Capacity Lithium Iron Phosphate Batteries
Authors: Zhang Zhihang , Lu Languang , Li Yalun , Wang Hewu , Ouyang Minggao
Published: September 2023

Large-capacity lithium iron phosphate (LFP) batteries are widely used in energy storage systems and electric vehicles due to their low cost, long lifespan, and high safety. However, the lifespan of batteries gradually decreases during their usage, especially due to internal heat generation and exposure to high temperatures, which leads to rapid capacity degradation. In-depth research is needed on the degradation characteristics of large-capacity LFP batteries under high temperatures. To study the degradation characteristics of large-capacity LFP batteries at high temperatures, a commercial 135Ah LFP battery is selected for 45°C high-temperature dynamic cycling aging experiments and 25°C reference performance experiments. A detailed analysis of the degradation process is conducted by examining the patterns of changes in charge-discharge voltage curves, capacity, internal resistance, open circuit voltage (OCV), and incremental capacity curve. The study uncovers that the OCV displays diverse degradation patterns at different states of charge (SOC). Furthermore, it identifies the loss of lithium inventory and active material as the fundamental factors contributing to the degradation observed during high-temperature cycling. This study provides references for developing battery life prediction algorithms and designing long-cycle-life battery cells.
Research on Photovoltaic Carport System Performance
Authors: Guo Cuishuang , Liu Ziqing , Pei Xuliang , Sun Chao , Zhang Yi
Published: September 2023

The demand and quantity of photovoltaic carports are increasing rapidly in recent years, and in this study the factors affecting the performance of photovoltaic carport components based on the electricity generation data from a factory in Tianjin, China are analyzed. The research validates that HJT and TOPCon modules outperform PERC double-glass modules and PERC modules in terms of electricity generation efficiency. Practical tests were conducted under various weather conditions such as sunny, cloudy, snowy, and enclosed environments, and the study results demonstrate that under the same low-light conditions, N-type modules exhibit better performance. The comparison of low-light performance among the four module types is as follows: HJT modules > TOPCon modules ≈ PERC double-glass modules > PERC modules. Due to the higher distance between photovoltaic carport modules and the ground, the performance of the bifacial module is significantly affected. In snowy conditions, the cost-effectiveness of PERC double-glass modules in photovoltaic carports is higher than that of TOPCon modules. In sunny and cloudy conditions, HJT modules show a higher increase in electricity generation. This study also examines the impact of enclosing the bottom space of photovoltaic carports on the electricity generation performance of TOPCon modules and PERC double-glass modules, revealing that TOPCon modules experience more power loss. The analysis of the practical operation of the four module types under various conditions are summaried in this paper, which providing valuable insights for the development of future solar cell technologies and the selection strategy of photovoltaic modules in different scenarios.
An Automatic Drying System Combining Photovoltaic, Photothermal, and Energy Storage
Authors: Wen Zhimei , Yuan Jiapu , Guo Xiaohong , Yang Yong , Tian Cheng
Published: September 2023

A solar air collector is composed of double-tube vacuum tubes, and the air collector is designed as an automatic drying system. Compared with the fossil fuel drying system, this system has better economic and social benefits. After theoretical calculation and experimental research analysis, the total energy saving of the drying system is 127564 MJ/year, with a cost saving of 21685.88 yuan/year and a static recovery period of 2.3 years; The experiment of drying 100 catties of sweet potatoes showed that the system can meet the needs of users for drying agricultural products. This system uses solar energy as its energy source, with zero pollution and zero emissions, and has certain promotion and application value.
Design of permanent magnet synchronous motor control system for electric vehicle air conditioning compressor
Authors: Wei Qi
Published: September 2023

The permanent magnet synchronous motor (PMSM) is extensively utilized in electric vehicle air conditioning compressor control systems due to its numerous advantages, including high efficiency, lightweight design, compact size, excellent reliability, and low maintenance costs. In order to achieve PMSM without position sensor full speed range operation, this paper designs an optimized control strategy for full speed range operation. At low and zero speed, the I/F control mode is employed to achieve quick motor startup with minimized repetition rate, avoiding the overcurrent problem that is easy to occur by traditional V/F control, and the control is switched to the Phase-locked Loop (PLL) adaptive sliding mode observer (SMO) for position estimation at medium and high speed, avoiding the problems of high-frequency jitter and low position accuracy of traditional SMO. The feasibility of this strategy is confirmed by the simulation results of Simulink.
Autonomous charging docking control method for unmanned vehicles based on vision and infrared
Authors: Zhou Yunya , He Yang , Yan Yu , Li Fang , Li Neng , Zhang Chaofeng , Lu Zijian , Yang Zhiyong
Published: September 2023

Unmanned vehicle charging is part of the autonomous workflow of unmanned vehicles. Most existing unmanned vehicles mostly rely on manual battery change or manual charging, which cannot realize autonomous charging. In order to achieve simpler and safer autonomous charging for unmanned vehicles, this paper proposes a new intelligent unmanned vehicle autonomous charging docking method based on infrared guidance and vision assistance. Firstly, the autonomous charging device and intelligent charging stand for unmanned vehicles are designed, and for the unmanned vehicle, charging is not easy to align and easy to detach when charging. The camber-type electric core and charging adsorption device are designed, respectively, and the autonomous charging docking device is designed. Secondly, in order to ensure the accuracy of the docking between the unmanned vehicle and the intelligent charging stand, the unmanned vehicle autonomous charging method is proposed. The combination method of infrared and vision adjusts the posture of the unmanned vehicle. Finally, a protection method of autonomous charging docking based on ultrasonic ranging of unmanned vehicles is proposed. The communication and ranging modules on the unmanned vehicle and intelligent charging stand are designed to prevent mistouching and obstacle avoidance to ensure the safety of the system. The experiment results show that the docking method of this unmanned vehicle autonomous charging system is accurate, efficient, and safe, which can satisfy the demand for unmanned vehicle autonomous charging.
Investigation of Permanent Magnet Vernier Machines with different PM Arrays
Authors: Fan Xun , Ding LingWei , Xiong Ling , Hu Xin , Zhang Meng , Ren QiuYe , Xie YinPeng , Cai Cheng
Published: September 2023

Two new five-phase out-rotor inner-stator permanent magnet (PM) vernier machines (PMVM) with different PM arrays are proposed to investigate the performance compared with an existing PMVM. The Halbach arrays and consequent arrays are adopted to enhance torque density. Also, the operation principle of PMVM is discussed by an analytical method. Moreover, some parameters are optimized to achieve better performance. Finally, performance such as back electromotive force, torque, loss, and efficiency are discussed by the finite element method.
The Doubly-fed Wind Power Generator Virtual Synchronous Control
Authors: Yin Meiling
Published: September 2023

Given the high proportion of wind power frequency/voltage stability problems, the power system based on synchronized coordinates (DFIG) mathematical model of doubly-fed motor, studies a current source containing inertial link type wind turbine virtual synchronous control strategy, and the virtual synchronous control loop and the current control design of the inner ring. Established in the Matlab/Simulink simulation model of doubly-fed wind power generator, the virtual synchronous generator realized virtual synchronous generator inertia. Simulation results confirm the validity of the theoretical analysis and the effectiveness of the proposed control strategy.
Design of a Q-band waveguide to CPW transition
Authors: Zou Huiyao , Sun Shufeng , Zhang Xiaoyang
Published: September 2023

A design scheme of waveguide to co-planar waveguide probe transition structure is proposed in this paper, and the structure is modeled and optimized by Ansoft’s electromagnetic simulation software HFSS. The simulation results indicate that the structure’s reflection coefficient is below -20dB and its insertion loss is below -0.3dB at 38∼47GHz. The structure is applicable to tile-type T/R modules.
Sliding mode control strategy for grid-connected inverters based on boundary layer
Authors: Liu Chuang , Wang Yanping
Published: September 2023

A sliding mode controller is designed to effectively track the reference current for the characteristics of conventional grid-connected controllers that cannot perform static-free tracking. and aiming at the jitter phenomenon of sliding mode controller, a boundary layer-based sliding mode controller is designed, which adopts traditional linear control inside the boundary layer and sliding mode control outside the boundary layer. the error is limited to a certain range and a compensation term is used to improve the problem of slow control speed. The proposed strategy is validated by simulation using matlab simulation software, and the simulation results prove that the proposed strategy can achieve grid current and grid voltage in the same frequency and phase, which proves the effectiveness of the proposed strategy.
Simulation Research of the Energy Storage System based on Unitized Regenerative Fuel Cell
Authors: Jia Xiaoqiang , He Guixiong , Liu Kaicheng
Published: September 2023

The Unitized Regenerative Fuel Cell (URFC) is an advanced energy storage system that integrates a fuel cell and an electrolysis cell. In this paper, MATLAB/Simulink is used to construct mathematical models of URFC. Through the steady-state simulation, it is found that with the increase in temperature, the output voltage of fuel cell mode increases, and the electrolysis mode voltage decreases. The highest efficiency reaches 41.8% at 80°C. As the pressure increases, the performance of URFC improves but requires good packaging and gas sealing. 1 MPa is the optimal pressure value considering URFC operating efficiency.
Research on the control strategy of interlinking converters for photovoltaic storage hybrid microgrid
Authors: Guo Xu , Chen Qigong , Li Ao , Wei Junqiu
Published: September 2023

This article mainly solves the problem of accurate power distribution and stable running in the photovoltaic storage hybrid microgrid and studies different control strategies of the interlinking converter connected to the AC-DC subnet under on-grid and off-grid conditions. The relationship between DC-side voltage, active power and active current is analyzed in the on-grid, and the DC voltage stability is supported by using a closed-loop voltage and current; in the off-grid mode, an improved bidirectional sag control method based on unitization processing is adopted, in which the power to be transmitted by the converter is differed from the actual value as the reference input of the current loop on the traditional double sag control, which can coordinate the power transmission between subgrids more precisely; And the action threshold is designed for the problem of repeated switching of converter operating modes. The results of simulation show that the converter able effectively to judge the magnitude and power direction in both parallel and off-grid operation modes, which ensures the normal operation of the important loads inside the subnets on both sides, thus verifying the feasibility of the control method.
Discharge Characteristics of Needle Plate Electrode in Transformer Oil Under Low-frequency AC Voltage
Authors: Liang Jiabi , Wu Peng , Li Jiansheng , Lu Yuncai
Published: September 2023

Low-frequency transformer is the key equipment of flexible low-frequency AC transmission systems for offshore wind power. As the low-frequency voltage is applied, the transformer has significantly different insulation characteristics from those of the conventional transformer, it is necessary to study the typical characteristics of partial discharge of oil-paper insulation under such voltage. In this dissertation, the characteristics of discharge of needle plate electrodes in transformer oil under power frequency to low-frequency voltage are experimentally researched by adopting the pulse current method, and the discharge statistics, discharge atlas as well as feature parameters are analysed. With the decreasing of voltage frequency, the inception voltage (IV) value of partial discharge slightly increases, the extinction voltage (EV) phases of positive half-cycle (PHC) voltage waveform, as well as negative half-cycle (NHC) voltage waveform appear earlier, and the maximum discharge (MD), average discharge (AD), and pulse repetition rate (PRR) all show a downward trend.
Research on Accurate Fault Location of Small Current Grounding System
Authors: Liu Denghui , Hao Cheng
Published: September 2023

Based on the principles of single-end fault ranging and signal injection method, a method of identifying fault distance parameters based on disturbance signal injection is proposed. The simulation calculation results verify that the method can effectively exclude the influence of line distribution capacitance on fault location accuracy while bearing a large range of transition resistance, and the impact of the arc extinguishing coil can be avoided by adjusting the signal injection module opening and closing time, which has high practical value in engineering.
Multi-objective optimization study of CCHP-GSHP-PV-ST system under different climatic zone conditions
Authors: Zeng Rong , Long Xiang
Published: September 2023

In this research, a system with multiple energy sources of combined cooling, heating, and power (CCHP)/ground source heat pump (GSHP)/photovoltaic (PV)/solar thermal collector (ST) (CCHP-GSHP-PV-ST system) is constructed. And this system is combined with the operation strategy of following total electric demand, that is, giving priority to meeting the electrical load of the building, the additional power of the coupling system, and the power of driving the GSHP. Therefore, a model for multi-objective optimization of the CCHP-GSHP-PV-ST system based on energy, environment, and economic indicators is established, and the optimization model is resolved using the genetic algorithm. The load simulation of office buildings in representative cities of five climate zones in China (Harbin (severe cold climate), Beijing (cold climate), Kunming (mild climate), Guangzhou (hot summer and warm winter climate), Changsha (hot summer and cold winter climate)) was selected as the basis for coupling system optimization, and the multi-objective optimization study of CCHP-GSHP-PV-ST system under different climate zone conditions was carried out. The findings indicate: (1) Under various climatic zone conditions, the coupling system’s optimized composition varies a little; (2) The multi-energy coupled system of office buildings in Beijing (cold climate) has primary energy saving rates, carbon dioxide emission reduction rates, annual total cost saving rates, and comprehensive performance that are respectively 46.06%, 60.43%, 44.05%, and 50.18% better than the split-production system when compared to other climate zones.
A Parameter Tuning Method of Adaptive Dynamic PID Controller for Time Delay Integral System
Authors: Wang Ruihao , Chen Yan , Shao Mingzhi , Zhao Zhenyu , Sun Haitao
Published: September 2023

PID controllers are widely used in the control of integral systems. In the practical application of integral systems, the control effect is usually affected by the delay time, and at the same time, the large variation of the controlled integral parameters will also affect the control effect of the controller. This paper proposes an adaptive dynamic PID controller parameter tuning method suitable for time delay integral systems, considering the influence of parameters such as the voltage of the integral system, the variation range of the controlled object, and delay time, making the relationship between the parameters of the PID controller and the control object of the integral system more explicit. At the same time, this paper considers the tuning of the differential filter parameters in practical applications. A non-linear system with a 10-fold variation of the controlled integral parameters is simulated in Simulink, and the dynamic control of the non-linear system is realized using the method proposed in this paper, achieving a better control effect compared to the traditional control with constant PID parameters.