bluuebunny/crossref_metadata_2025 huggingface dataset:
Layer-by-layer assembly of a [Fe-(pyrazine){Pd(CN)4}] spin crossover thin film
Authors: McElveen Kayleigh A , Hao Guanhua , Evans Prescott E , Ekanayaka Thilini K , N’Diaye Alpha T , Chin Wai Kiat , Lai Rebecca Y
Published: August 2024

[Fe-(pyrazine){Pd(CN)4}] (pyrazine = pz) thin films were fabricated using a layer-by-layer assembly approach, a method known to be tunable, versatile, and scalable, since thin films are better-suited for industrial applications. In this study, [Fe-(pz){Pd(CN)4}] powder was synthesized, and the results obtained from a vibrating sample magnetometer verified the presence of an abrupt hysteresis loop with widths of 45 K centered around 300 K, indicating good cooperativity. Super conducting quantum interference device magnetometry results indicated a slow spin transition with temperature but with evidence of hysteresis for thin film samples. X-ray absorption analysis provided further support of the spin crossover behavior but differs from the magnetometry because the spin state transition at the surface differs from the bulk of the thin film. X-ray photoelectron spectroscopy provided some insight into issues with the film deposition process and multiplex fitting was used to further support the claim that the surface of the film is different than the bulk of the film.
A method for extracting and screening main feature points based on salient geometric characteristics and NAD features
Authors: Wang Ziyang , Ren Bingyin , Dai Yong
Published: August 2024

Point cloud alignment is an important task in the field of industrial automation and computer vision recognition. Aiming at the lack of robustness of traditional alignment algorithms in the face of cylindrical objects such as motors or highly symmetric objects, which in turn is prone to poor alignment accuracy or even alignment failure, a method of extracting and screening main feature points based on salient geometric properties is proposed to provide high-precision inputs for point cloud alignment and to improve the position estimation accuracy of symmetric targets. The salient geometric planes and curved surfaces in the target are utilized as the basis of feature point selection to extract more robust main feature points; and different feature descriptors are adopted to describe the feature points based on the target characteristics, which greatly preserves the original main contour and geometric information. A local feature descriptor normalized angle descriptor is designed based on the normal vector, normal angle and Euclidean distance of the point cloud, which is able to effectively remove the incorrect correspondences due to symmetry and feature similarity. Finally, the algorithm for obtaining the global maximum consensus set (GROR) based on the node and edge reliability of the correspondence graph is used to complete the coarse registration, and the iterative closest point algorithm is utilized to complete the fine registration. Experimental results on motor point clouds taken from different viewpoints show that the proposed registration strategy is visually and numerically superior to existing state-of-the-art methods, especially when there is only a single-frame point cloud of the target.
A fast forward-looking super-resolution imaging method on a high-speed platform
Authors: Wang Lequn , Wang Wei , Shao Xuehui , Hu Ziying
Published: August 2024

Radar forward-looking imaging has raised many concerns in the civilian field. However, when employing forward-looking imaging methods on a high-speed platform, traditional Doppler compensation methods can result in significant compensation errors and exceed the Doppler compensation boundary. At the same time, the forward-looking geometric configuration results in the mutual coupling of range and Doppler information and the corresponding Doppler convolution matrix needs to be constructed per range cell. In addition, the large matrix dimensions of the convolution matrix result in enormous computational complexity. This paper proposes a fast super-resolution method based on high-speed platform Doppler compensation and a low-rank approximation batch processing (LRA-Batch) framework. First, the Doppler compensation matrix for high-speed platforms to eliminate Doppler centroid spatial variations in the range direction is constructed. Then, the Doppler convolution matrix only needs to be constructed once after compensation. The forward-looking imaging model under high-speed platforms has been improved through the above-mentioned method. Next, the sparse reconstruction optimization problem corresponding to the forward-looking super-resolution imaging model is reformulated into the matrix form, and the matrix dimension is reduced through low-rank approximation. Subsequently, the 2D echo data can be processed directly, avoiding the high computational complexity associated with line-by-line processing. The relevant simulation experiments to evaluate the performance of the proposed method have been designed. Simulation results prove that the proposed LRA-Batch method can obtain effective reconstruction results under low operational complexity.
Experimental study on plasma characteristics in the extraction region of a high-power RF negative ion source based on electrostatic probe
Authors: Peng Xufeng , Xu Yongjian , Xie Yahong , Wei Jianglong , Li Yufan , Yang Yuwen , Liu Bo , Xie Junwei , Wu Bin
Published: August 2024

The plasma characteristics of the extraction region in high-power RF negative ion source have a significant impact on the production and extraction of negative hydrogen ions. This study utilized electrostatic probe to investigate the effect of RF power, source pressure, magnetic filter field and bias voltage on the plasma parameters of the extraction region (without cesium), and also studied the variation of plasma parameters with position and time. The results indicate that as RF power increases, the plasma density in the extraction region significantly rises, but it also leads to an increase in the electron temperature (

T

e

) of the extraction region (which increases the loss of negative hydrogen ions); increasing the source pressure can effectively increase the electron density (

N

e

) in the extraction region and reduce

T

e

as expected; increasing the magnetic filter field can effectively reduce the

T

e

in the extraction region, but after the plasma grid current exceeds 1900 A, the change in

T

e

is not significant; although increasement of the bias voltage can effectively suppress the

N

e

in the extraction region, it causes

T

e

to rise; moreover, the distribution of plasma parameters in the extraction region is relatively uniform; in addition, the variation of plasma parameters with time is not obvious. These findings not only deepen the understanding of the physical mechanisms of plasma behavior in the extraction region of negative ion sources, but also provide important theoretical and experimental bases for the optimization of high-power RF negative ion sources.
Numerical investigation of vacuum ultra-violet emission in Ar/O2 inductively coupled plasmas
Authors: Osca Engelbrecht Michel , Jenderny Jonathan , Hylla Henrik , Filla Dominik , Awakowicz Peter , Korolov Ihor , Ridgers Christopher P , Gibson Andrew R
Published: August 2024

Controlling fluxes of vacuum ultraviolet (VUV) radiation is important in a number of industrial and biomedical applications of low pressure plasma sources because, depending on the process, VUV radiation may be desired, required to a certain degree, or unwanted. In this work, the emission of VUV radiation from O atoms is investigated in low-pressure Ar/O2 inductively coupled plasmas via numerical simulations. For this purpose, a self-consistent Ar/O2 plasma-chemical reaction scheme has been implemented in a zero dimensional plasma chemical kinetics model and is used to investigate VUV emission from excited O atoms (3s 5S

2
0

and 3s 3S

1
0

) at 130 and 135 nm. The model is extensively compared with experimental measurements of absolute VUV emission intensities, electron densities and Ar excited state densities. In addition, oxygen VUV emission intensities are investigated as a function of pressure, Ar/O2 mixture, and power deposition and the dominant reaction pathways leading to oxygen VUV emission are identified and described. In general terms, absolute oxygen VUV emission intensities increase with power and oxygen fraction over the ranges investigated and peak emission intensities are found for pressures between 5–50 Pa. The emission is dominated by the 130 nm resonance line from the decay of the O(3s 3S

1
0

) state to the ground state. Besides, at low pressure (0.3–1 Pa), the flux of oxygen VUV photons to surfaces is much lower than that of positive ions, whereas oxygen VUV fluxes dominate at higher pressure,

≳

5–50 Pa depending on O2 fraction. Finally, oxygen atom fluxes to surfaces are, in general, larger than those of VUV photons for the parameter space investigated.
Unveiling correlated two-dimensional topological insulators through fermionic tensor network states—classification, edge theories and variational wavefunctions
Authors: Xu Chao , Ma Yixin , Jiang Shenghan
Published: August 2024

The study of topological band insulators has revealed fascinating phases characterized by band topology indices and anomalous boundary modes protected by global symmetries. In strongly correlated systems, where the traditional notion of electronic bands becomes obsolete, it has been established that topological insulator phases persist as stable phases, separate from the trivial insulators. However, due to the inability to express the ground states of such systems as Slater determinants, the formulation of generic variational wave functions for numerical simulations is highly desirable. In this paper, we tackle this challenge for two-dimensional topological insulators by developing a comprehensive framework for fermionic tensor network states. Starting from simple assumptions, we obtain possible sets of tensor equations for any given symmetry group, capturing consistent relations governing symmetry transformation rules on tensor legs. We then examine the connection between these tensor equations and non-chiral topological insulators by constructing edge theories and extracting quantum anomaly data from each set of tensor equations. By exhaustively exploring all possible sets of equations, we achieve a systematic classification of non-chiral topological insulator phases. Imposing the solutions of a given set of equations onto local tensors, we obtain generic variational wavefunctions for the corresponding topological insulator phases. Our methodology provides an important step toward simulating topological insulators in strongly correlated systems. We discuss the limitations and potential generalizations of our results, paving the way for further advancements in this field.
Emotion recognition of EEG signals based on contrastive learning graph convolutional model
Authors: Zhang Yiling , Liao Yuan , Chen Wei , Zhang Xiruo , Huang Liya
Published: August 2024

Objective. Electroencephalogram (EEG) signals offer invaluable insights into the complexities of emotion generation within the brain. Yet, the variability in EEG signals across individuals presents a formidable obstacle for empirical implementations. Our research addresses these challenges innovatively, focusing on the commonalities within distinct subjects’ EEG data. Approach. We introduce a novel approach named Contrastive Learning Graph Convolutional Network (CLGCN). This method captures the distinctive features and crucial channel nodes related to individuals’ emotional states. Specifically, CLGCN merges the dual benefits of CL’s synchronous multisubject data learning and the GCN’s proficiency in deciphering brain connectivity matrices. Understanding multifaceted brain functions and their information interchange processes is realized as CLGCN generates a standardized brain network learning matrix during a dataset’s learning process. Main results. Our model underwent rigorous testing on the Database for Emotion Analysis using Physiological Signals (DEAP) and SEED datasets. In the five-fold cross-validation used for dependent subject experimental setting, it achieved an accuracy of 97.13% on the DEAP dataset and surpassed 99% on the SEED and SEED_IV datasets. In the incremental learning experiments with the SEED dataset, merely 5% of the data was sufficient to fine-tune the model, resulting in an accuracy of 92.8% for the new subject. These findings validate the model’s efficacy. Significance. This work combines CL with GCN, improving the accuracy of decoding emotional states from EEG signals and offering valuable insights into uncovering the underlying mechanisms of emotional processes in the brain.
Effect of parallel flow on resonant layer responses in high beta plasmas
Authors: Lee Yeongsun , Park Jong-Kyu , Na Yong-Su
Published: August 2024

Resonant layers in a tokamak respond to non-axisymmetric magnetic perturbations by amplifying the mode amplitude and balancing the plasma rotation through magnetic reconnection and force balance, respectively. This resonant response can be characterized by local layer parameters and especially by a single quantity in the linear regime, the so-called inner-layer Δ. The computation of Δ under two-fluid drift-MHD formalism has been progressed by reducing the order of the system in the phase space, where the shielding current is approximated as being only carried by electrons, a posteriori. In this study, we relax the approximation and compute Δ accounted for by the parallel flow associated with the ion shielding current. The posteriori is numerically verified in great agreement with the original SLAYER developed in a previous paper (J.-K. Park 2022 Phys. Plasmas
29 072506). Extending the resonant layer response theory to high β plasmas, our research findings answer two important questions: how the parallel flow influences the resonant layer response and why the parallel flow effect appears in high β plasmas. The complicated plasma compression in high β regime allows the parallel flow response to give rise to the ion shielding current, which not only shifts the zero-crossing condition of the ExB flow but also enhances the field penetration threshold. Technically, the Riccati matrix transformation method is adapted to handle the numerical stiffness due to the increased order of the system. The high fidelity of this numerical method makes use of further extension of the model to higher-order systems to take other physical phenomena into account. This work is envisaged to predict the resonant layer response under high β fusion reactor conditions.
Electron transport barrier and high confinement in configurations with internal islands close to the plasma edge of W7-X
Authors: Chaudhary N. , Hirsch M. , Andreeva T. , Geiger J. , Wolf R.C. , Wurden G.A. ,   the W7-X Team
Published: August 2024

The low magnetic shear in the Wendelstein 7-X (W7-X) stellarator makes it feasible to shape the separatrix by the large islands constituting an island-divertor, and this can be exploited to access various magnetic configurations, including samples of different internal island sizes and locations. To investigate the configuration effects on the plasma confinement, a configuration scan was performed by changing the coil currents to vary the rotational transform between values

5

/

4

and

5

/

6

at the plasma boundary with different power levels (2, 4, 6 MW) of electron cyclotron resonance heating (ECRH) at a maximum plasma density of

8
×

10

19

m

−
2

. neutral beam injection (NBI) heating was also applied during some configurations of the scan to create a density ramp and access high densities beyond the X2 ECRH cutoff. For the magnetic configurations, where the

5

/

5

and

5

/

6

island chains were moved closer to separatrix but remaining inside the last closed flux surface, the electron cyclotron emission shows that an electron temperature,

T

e

, pedestal develops already during ECRH heated plasma buildup phase indicating a transport barrier, and the barrier sustains irrespective of changed plasma heating conditions such as NBI in the later part of discharge. The transport barrier is broken by subsequent fast crashes, observed with multiple plasma diagnostics with characteristics such as tokamak edge localized modes, and the corresponding crash amplitude and frequency vary with plasma pressure. The impact of the transport barrier on plasma confinement can be seen through the increased core

T

e

profile, which could be responsible for the overall increase in the stored diamagnetic energy by approximately 10% for these configurations. After the plasma heating is terminated, a backwards transition to a degraded confinement state is also observed. These observations indicate a configuration triggered high confinement mode in low shear W7-X. This work focuses on the occurrence of this transport barrier for different magnetic configurations and its relation to internal magnetic islands.
Effect of the downstream blockage induced under-rib convection on oxygen feeding in a PEMFC with parallel flow field
Authors: Ding Zhonghang , Ye Qiang
Published: August 2024

In the parallel flow field of a proton exchange membrane fuel cell (PEMFC), liquid water could totally block a channel, potentially inducing under-rib convection between the blocked channel and adjacent unblocked ones. This work establishes a three-dimensional PEMFC model with three parallel-connected channels on the cathode side, specifically focusing on the middle channel, which simulates blockage caused by liquid water. Our findings indicate that the blockage-induced under-rib convection could reach velocities up to 0.1 m s−1, suggesting that it plays a key role in maintaining oxygen supply to the catalyst layer despite the blockage. However, reducing the gas diffusion layer’s permeability to a tenth of its intrinsic value significantly weakens this convection, leading to localized oxygen starvation and up to 15% performance loss. These findings highlight the critical role of under-rib convection in mitigating the adverse effects of channel blockages on PEMFC performance and underscore the need for optimized design and operational strategies to manage liquid water within the cell.
Research on variable pressure oil supply servo system based on accumulator
Authors: Wang Qiang , Zhu Pengcheng , Chen Liugang , Zhang Xingbin , Wang Shufen
Published: August 2024

In some special engineering applications, actuators are required to operate at high speed and heavy load in a short period of time, and in order to save the installed power of the pumping station, the accumulator can be used as a power source. In order to effectively overcome the influence of the accumulator oil supply pressure on the system accuracy, a variable pressure oil supply servo system based on the accumulator is designed. The results show that the designed controller has faster response speed and higher control accuracy than the PID controller, and can effectively overcome the influence of the drop of oil supply pressure of the accumulator.
Optimal scheduling of building integrated energy system considering the interaction of electric energy and heat energy
Authors: Zhang Qi , Wu Gaoxiang , Li Zhe , Yang Huaxiao , Dai Jian
Published: August 2024

This research focuses on optimizing smart building energy systems to improve energy efficiency, lower operational costs, and support environmental sustainability. We’ve developed an intelligent energy management framework by integrating advanced control strategies and technologies. This framework spans energy generation, conversion, storage, and utilization, allowing for coordinated scheduling of electricity and thermal energy from various sources. Through mathematical modeling, we accurately describe the real-time operational characteristics of system devices. Our simulation experiments confirm the effectiveness of these optimization strategies, showing significant performance enhancements across diverse operating conditions. This study offers strong theoretical support for designing and managing smart building energy systems, contributing positively to the sector’s future development and sustainability.
Research on SOC-constrained SOP estimation technique based on static operating conditions
Authors: Yang Chao , Ye Zhihao , Xiong Xin , Wang Zerun
Published: August 2024

In this study, we explore a novel method for estimating the System Operating Power (SOP) in battery management systems (BMS) by leveraging measurements of open circuit voltage (OCV), state of charge (SOC), and battery current. Through the analysis of battery performance during dynamic stress test (DST) conditions, this method calculates the continuous maximum currents for both charging and discharging scenarios. Subsequently, it estimates the peak power for these processes. By comparing these estimates with experimental data, it is evident that the proposed algorithm significantly enhances the precision of SOP estimations. This improvement not only boosts the accuracy of the SOP calculations but also contributes to the optimization of the BMS, enhancing the overall performance and longevity of the power batteries.
Study on the flexible control method of thermal storage technology participating in the power grid
Authors: Chen Guoqing
Published: August 2024

Energy storage technology is significant in the construction of new power systems. Heat storage is one of the technical energy storage routes, which can help the power grid to shift the peak and fill the valley. However, the flexible control method of heat storage technology participating in the power grid has not been deeply investigated. In this study, a flexible control model is built and the control strategy is proposed. The flexible control model introduces a load aggregator to realize flexible load control and benefit all the participants through the four-market trading mode. The flexible control strategy is different based on different scenarios, including the new energy consumption period, peak cutting period, and ordinary period. The case analysis shows that when the aggregator subsidizes the user at 0.25 yuan/kWh in the heating season, the overall benefit is the largest and the income distribution among all the participants is the most reasonable.
Study on the effect of hydrogen doping on engine emission characteristics
Authors: Zhang Qian , Wang Shangxue , Sun Tingting , Liu Zhiyu
Published: August 2024

The emission characteristics of the entire engine after hydrogen blending combustion in the intake system under different loads and external characteristic operating conditions were studied through experimental methods. The research results show that under various operating conditions of hydrogen/oxygen mixed combustion, CO and HC emissions show significant reduction rates at medium and low speeds, with maximum reduction rates of 11.5% and 46.67%, respectively. At medium and low speeds, hydrogen has a more significant impact on emissions than that at higher speeds and high loads. Experiments have shown that adding an appropriate amount of hydrogen to the engine intake can significantly enhance the combustion process of the mixture, improve cycle thermal efficiency, and as a result, reduce CO and HC emissions.
Research on the flow and heat transfer performance of variable geometry high-pressure turbine blade tip area of gas turbine
Authors: Li Yujie , Wang Wen , Liu Yalei
Published: August 2024

Carrying out the research of geometric turbine region flow and heat transfer research, and optimizing the configuration of the end zone is of great significance to improve turbine performance. In response to the complex second flow and heat transfer caused by the interval space of geometric turbine blades, this article starts from the perspective of reducing the pneumatic loss of the end zone and improving the heat transfer. The numerical method is used to study the adjustment of the turbine non-uniform import conditions, which can be adjusted. Studies have found that the configuration of the static leaf end zone weakens the cross-speed flow and leakage flow of the interval space of the rear end. At the same time, the coverage of the cooling gas on the wall surface of the end zone is also reduced. The separation of front side of the interval space is separated, and the average heat transfer coefficient of the wall surface is reduced, which has the best air thermal performance.
Investigation of electrochemical behavior of cerium in LiCl-KCl eutectic molten salt by modeling
Authors: Ding Yuncong , Zhang Xinyu , Xu Xiaorui , Yin Yuan , Zhou Wentao
Published: August 2024

Pyroprocessing is one of the promising candidates for reprocessing the spent nuclear fuel for the sustainable development of nuclear energy. A deep understanding of electrochemical phenomena is indispensable for the precise design and optimal functioning of an electrolytic cell system dedicated to pyroprocessing. In the present study, cyclic voltammetry and electrorefining processes were simulated by the finite element method, and the accuracy of the model was verified by experimental comparison. The influences of initial bulk concentration and temperature on cyclic voltammetry were investigated. The electrorefining process, including the potential distribution, as well as the changes of total current and deposition mass with time, were also explored. The results of this study will contribute significantly to understanding the molten salt electrolysis for pyroprocessing.
Study on the bearing performance of all-steel spiral anchor in silty clay
Authors: Wang Teng , Zhao Yong , Han Wei , Gao Zhiyue , Li Cuiling , Zhang Zhenyue , Zhang Bingliang , Zhu Huimin
Published: August 2024

The all-steel spiral anchor demonstrates exceptional advantages in terms of construction convenience and rapid deployment. To validate its Application in transmission engineering, an extensive field study was conducted to investigate the influence of inclination angle, buried depth, and anchor specifications on its load-bearing performance. The findings reveal that the load-bearing capacity of an individual anchor foundation is significantly influenced by these factors. Specifically, with a constant anchor rod burial length, an increase in the inclination angle leads to a relative decrease in the soil-embedded depth of the spiral anchor, thereby reducing its pull-out resistance. Furthermore, a direct correlation is evident between the pull-out resistance of spiral anchors and their embedment depth. Notably, changes in buried depth have minimal impact in the early stages of loading. However, as the load progressively increases, the force exerted on the anchor plate significantly escalates with displacement, resulting in a growing influence of embedment depth on the anchor’s load-bearing capacity. Enhancing the size and number of anchor components has been observed to have a favorable effect on the overall load-bearing capability of the anchor system. As displacement increases, upward displacement of the anchor plate compresses the surrounding soil, making the anchor plate’s contribution more pronounced and eventually surpassing that of the anchor rod.
A study on SOC prediction enhancement using STEKF in lithium batteries
Authors: Xu Guoqi
Published: August 2024

Accurate State of Charge (SOC) estimation for lithium batteries is essential for optimizing battery performance and lifespan. This research proposes a SOC prediction technique utilizing the Strong Tracking Extended Kalman Filter (STEKF) to overcome the drawbacks of the conventional Extended Kalman Filter (EKF) in highly dynamic and uncertain scenarios. By dynamically modifying the error covariance matrix, STEKF greatly improves the adaptability and precision of the prediction model. Experimental findings indicate that STEKF decreases the Root Mean Square Error (RMSE) from 4.7% to 1.9% at 25°C, surpassing the traditional EKF and providing a more accurate and reliable SOC prediction method for electric vehicle battery management systems (BMS).
Mobile energy storage configuration approach considering multiple operational scenarios
Authors: Zhang Runkai , Zhao Guopeng , Zhang Tongfei , Peng Zepu , Wang Zhiqiang
Published: August 2024

Battery energy storage systems are widely used in the optimal operation of power grids due to their flexible regulation characteristics. This paper analyses the role of modular mobile energy storage applied under normal grid operation scenarios, random component failures, and extreme disaster scenarios in enhancing the benefits of the power system, establishes an optimization planning model to maximize the total net benefits of energy storage allocation in multiple operation scenarios, as well as solves problems through an improved evolutionary algorithm. The arithmetic example uses a real urban distribution network to check the feasibility as well as the effectiveness of the proposed method.
Coordinated method for islanding division and component restoration in active distribution networks aimed at enhanced resilience
Authors: Wang Cunyou , Xu Hang , Chang Xinli , Li Cancan
Published: August 2024

Due to the uncertainties associated with distributed generation output and load power consumption, distribution networks encounter challenges in component restoration and resilience enhancement. This paper proposes a three-layer min-max-min robust optimization model designed for coordinated optimization of islanding division and component restoration in the distribution network. Firstly, constraint models for distributed energy storage, distributed generation, load power consumption, line reconfiguration, component restoration, islanding division, and line power flow are established. Secondly, to maximize the resilience of the distribution network, a robust optimization model is performed with the objective function of minimizing the total load shedding during the component restoration phase. Finally, validated on the IEEE 33-node distribution system, the proposed method demonstrates that it can significantly enhance the resilience of the distribution network, enabling more precise and effective optimization scheduling.
Short-term household power load forecasting based on ICEEMDAN decomposition and CNN-BiLSTM-SA hybrid model
Authors: Shen Ruofeng , Yang Shuanglong
Published: August 2024

In recent years, the introduction of the dual carbon strategy has made the development of new power systems more and more crucial. The accurate and efficient prediction of household load has become a hot topic in this field. This paper proposes a hybrid model based on improved complete ensemble empirical mode decomposition with adaptive noise (ICEEMDAN), integrating convolutional neural networks (CNN), bidirectional long short-term memory (BiLSTM), and self-attention (SA) techniques, and incorporating the wavelet domain denoising (WDD) algorithm to enhance data smoothness. The spatial feature extraction capability of CNN and the bidirectional time series extraction capability of BiLSTM are fully utilized, and the ability of SA to highlight the key historical time node information is combined to reduce the loss of historical information. To validate the effectiveness of this method, real household load data is used for verification. Through comprehensive experimental results comparison from multiple perspectives, it is found that both prediction accuracy and error have been significantly improved, demonstrating great potential for this model in addressing increasingly complex new power systems in electrical engineering applications.
Land-air coupled environmental perception system during the construction phase of pumped storage power stations
Authors: Xu Shuangquan , Li Xiji , Xu Xiaoyan , Dong Haiyang , Liu Qing , Yan Licai , Zhang Yue
Published: August 2024

In response to the unique construction characteristics of pumped storage hydropower projects, this study focuses on selecting suitable onshore environmental monitoring equipment. It investigates a deployment plan for onshore environmental situational awareness devices based on the IOT technology and an aerial-based environmental situational awareness system utilizing a fleet of automated unmanned aerial vehicles. The approach involves adapting data monitoring according to the specific construction features and phases of the power station. When monitoring data indicates a trend exceeding standards, the system issues early warnings and provides disposal methods, which achieves touchless, intelligent, and resource-liberating environmental management, realizing specialized, standardized, and refined supervision of environmental protection. The goal is to enhance the digitalization of power stations while improving efficiency in environmental and water conservation management for pumped storage hydropower projects. The operational and practical outcomes of this project contribute to increased regulatory efficiency, and the proposed approach can be widely applied to other pumped storage projects and extended to projects in water resources or other sectors, fostering a market-oriented application.
Health status identification method of PV plant sensors based on abnormal data analysis
Authors: Yang Fangliao , Wang Weineng , Min Qi , Tan Hongzhi , Tian Jianwei
Published: August 2024

To achieve accurate control of the PV plant, various sensors are deployed. Identifying the health status can improve the safety of PV plants and the accuracy of PV power generation prediction. To enhance the accuracy of sensor fault type identification and make the process interpretable, a method for identifying the health status of PV plant sensors based on abnormal data analysis is proposed. The analysis including general fault types and abnormal data of PV plant sensors is analyzed. A model for detecting the type of abnormal data behavior is established, and fault diagnosis is performed based on the abnormal data behavior to determine the specific faults of the sensors. Experimental verification is carried out using data from three sensors: temperature, humidity, and light intensity in a PV plant. The experimental results show that the method can accurately and comprehensively identify the health status of PV plant sensors, with an accuracy of 99.53%, and an F1-score of 0.9825.
The effect of different Pre-welding microstructure on the final microstructure of CLAM steel after EBW welding
Authors: Liu Zhixian , Zhang Wenfeng , Zhou Qinhe , Yin Jingyun , Huang Canjun , Feng Lulu , Yan Wei
Published: August 2024

In this paper, different pre-weld microstructures of clam steel were obtained by heat treatment, and the seamless connection of the test steel was achieved by EBW welding. The microstructure and fracture morphology of the samples were observed by optical microscope and scanning electron microscope, and the composition of the second phase particles was detected by EDS. The results show that the joint microstructure was mainly composed of the melting zone and HAZ zone. The δ ferrite was detected in the melting zone, and the HAZ zone with fine grains was filled with carbides in and along the grain boundaries. B and N are mainly distributed on the grain boundary, and C exists in the form of a precipitated phase on the grain boundary and in the form of a solid solution in the grain.
The failure mechanism of ammonia suction pipe bursting under fire environment
Authors: Wang Weihua , Chen Jiugong , Li Jiaxing , Hu Li , Jing Weike
Published: August 2024

Liquid ammonia is widely used in the refrigeration industry, which brings serious challenges to the safety control of ammonia refrigeration systems due to its high danger, ease of exploding, and acute poisoning accidents. Current research on ammonia refrigeration equipment mainly focuses on accident hazard analysis, while the study on the failure mechanism of equipment under fire conditions is not deep enough. In this paper, the ammonia suction pipe with burst phenomenon was sampled, and the failure mechanism of the suction pipe under a fire environment was comprehensively studied by means of macroscopic examination, chemical composition analysis, metallographic examination, surface decarburization and fracture analysis, mechanical property test, and simulated heat treatment experiment. The results show that the failure mechanism of a suction pipe under a fire environment is a toughness overload fracture caused by the reduction of material strength. Affected by the high temperature of fire source combustion, the nitriding layer appears on the inner surface, and some decarburization occurs on the outer surface of the suction pipe. The microstructure of the fire-facing surface (the starting position of the tear) undergoes the pearlitic spheroidization phenomenon with the level of 3 grade, which reduces the strength and creep resistance of the material. The liquid ammonia in the pipe is rapidly expanded and gasified under a high-temperature environment, which produces high-pressure stress inside the pipe. Eventually, the pipe burst on the fire-facing surface, where the strength is the weakest.
Effect of shot peening pressure on fretting wear properties of 42CrMoA steel
Authors: Wang Zhiyuan , Yang Xuefeng
Published: August 2024

Due to the complexity and harshness of the spline’s working environment, the wear of teeth micro movement is severe, which will most likely lead to coupling failure and reduce the stability of the aerospace transmission system. This paper carries out air pressure 0.1MPa, 0.2MPa, 0.3MPa, 0.4MPa, and 0.5MPa shot peening on the commonly used material, 42CrMoA steel, to improve the wear resistance of the spline to study the wear resistance of the steel under different air pressure. The test results show that increasing the air pressure of shot peening can make the 42CrMoA steel surface residual stress and hardness first increase and then decrease, the depth of the hardened layer increases, wear resistance is improved, the wear mechanism from adhesive wear to abrasive wear.
An analysis of gear wear and micro-pitting evolution during contact fatigue
Authors: Guan Rongxin , Wang Dongfei , Yu Wentao , Chen Chao , Yang Shufeng
Published: August 2024

This work uses contact fatigue tests to study the wear and micro-pitting evolution on gear teeth. The study reveals a competitive relationship between wear and micro-pitting corrosion in gear contact fatigue. Experimental results demonstrate that micro-pitting initially appears at the root of the carburized and quenched gear teeth and gradually spreads across the entire tooth width during the running-in process. As micro-pitting occurs, the oil film thickness is continuously reduced, leading to the emergence of wear. Micro-pitting and wear coexist and develop competitively, but as the number of cycles reaches 16 million, wear causes the tiny pits on the tooth’s surface to vanish as the wear rate exceeds the expansion rate of micro-pitting. Both micro-pitting and wear alter the tooth surface morphology and profile in distinct manners.
Investigation of a novel 2.5 MV sintered diamond target beam for intracranial linac-based stereotactic treatments
Authors: Borsavage Jennifer M , Cherpak Amanda J , Robar James L
Published: August 2024

Purpose. This work investigates the small-field dosimetric characteristics of a 2.5 MV sintered diamond target beam and its feasibility for use in linac-based intracranial stereotactic treatments. Due to the increased proportion of low energy photons in the low-Z beam, it was hypothesized that this novel beam would provide sharper dose fall-off compared to the 6 MV beam owing to the reduced energy, and therefore range, of secondary electrons. Methods. Stereotactic treatments of ocular melanoma and trigeminal neuralgia were simulated for 2.5 MV low-Z and 6 MV beams using Monte Carlo to calculate dose in a voxelized anatomical phantom. Two collimation methods were investigated, including a 5 × 3 mm2 HDMLC field and a 4 mm cone to demonstrate isolated and combined effects of geometric and radiological contributions to the penumbral width. Results. The measured 2.5 MV low-Z dosimetric profiles demonstrated reduced penumbra by 0.5 mm in both the inline and crossline directions across all depths for both collimation methods, compared to 6 MV. In both treatment cases, the 2.5 MV low-Z beam collimated with the 4 mm cone produced the sharpest dose fall off in profiles captured through isocenter. This improved fall-off resulted in a 59% decrease to the maximum brainstem dose in the trigeminal neuralgia case for the 2.5 MV low-Z MLC collimated beam compared to 6 MV. Reductions to the maximum and mean doses to ipsilateral and contralateral OARs in the ocular melanoma case were observed for the 2.5 MV low-Z beam compared to 6 MV with both collimation methods. Conclusions. While the low dose rate of this novel beam prohibits immediate clinical translation, the results of this study support the further development of this prototype beam to decrease toxicity in intracranial SRS treatments.
Investigation of the beam quality and dose rate dependence of PAKAG polymer gel dosimeter in optical readout technique
Authors: Abtahi Seyed Mohammad Mahdi , Habibi Fatemeh
Published: August 2024

This study aims to evaluate the optical response dependence of the PAKAG polymer gel dosimeter on photon energy and dose rate. The produced gel dosimeters were irradiated using a Varian CL 21EX medical linear accelerator with delivered doses of 0, 2, 4, 6, 8, and 10 Gy. To examine the response dependence on the delivered dose rate, dose rates of 50, 100, 200, and 350 cGy min−1 were investigated. Additionally, two incident beam qualities of 6 and 18 MV were examined to study the response dependence on the incident beam energy. The irradiated polymer gel dosimeters were readout using a UV–vis spectrophotometer in the 300 to 800 nm scan range. The results reveal that a wide variation in dose rate (50–350 cGy.min−1) influences the absorbance-dose response and the sensitivity of PAKAG gel. However, smaller variations did not show a significant effect on the response. Furthermore, the response changed insignificantly with beam quality for investigated energies. It was concluded that the optical reading response of the PAKAG polymer gel dosimeter is satisfactorily independent of external parameters, including dose rate and incident beam quality.
Modeling N2O emissions with remotely sensed variables using machine learning
Authors: Adler Paul R , Nguyen Hai , Rau Benjamin M , Dell Curtis J
Published: August 2024

Nitrous oxide is the largest source of greenhouse gas emissions from crop production. There is significant interest in targeting marginal lands for growing biomass crops, however little information is available on how this will affect N2O emissions from these crops. Furthermore, to characterize N2O emission at the farm level to quantify mitigation using measurements is time intensive, costly, and impractical. We selected a highly diverse watershed varying in soil texture and topography to compare two approaches for modeling soil N2O emissions using machine learning, intensive measurements of soil environment and climate variables, with the other only using remotely sensed variables. We confirmed that soil nitrogen was the most important variable followed by soil environment as influence by soil characteristic, topography, and climate. We also found that the machine learning model built on remotely sensed variables performed as well as when direct site level measurements were available. This finding supports the potential of using remotely sensed data to build machine learning models to characterize soil N2O emissions without the need for intensive soil measurements for entity level assessments.
‘You’re Walking into Situations Where You Just Really Don’t Know How It’s Going to Go Down’: The Production of Carceral Space and Risk in Parole Work
Authors: Norman Mark , Ricciardelli Rosemary , Maier Katharina
Published: August 2024

Following interviews with 150 Canadian federal parole officers employed in prisons or community spaces, we ‘spatialize’ parole work by analysing how participants perceive and navigate risk and use emotional labour in relation to their carceral workspaces. Employing Henri Lefebvre’s theorization of the social production of space, we analyse how parole officers’ feelings of vulnerability arise from the interaction of the built environment with people’s use of space (including both criminalized persons and other correctional workers). We also unpack the strategies employed by parole officers to mitigate the spatial risks experienced in their occupational routines; and examine how these spatial experiences connect to the emotional labour performed by parole officers in their supportive and disciplinary job functions.
Prevalence of abdominal aortic aneurysm in patients with hidradenitis suppurativa in the Veterans Affairs Health Care System
Authors: Wendland Zachary , Rypka Katelyn , Herzog Claire , Greenlund Lindsey , Fulk Travis , Gravely Amy , Westanmo Anders , Garg Amit , Goldfarb Noah
Published: August 2024

Our study investigated the relationship between abdominal aortic aneurysm (AAA) and hidradenitis suppurativa (HS) in patients within the Veterans Affair Health Care System. Overall, we found that patients with HS had a higher prevalence of AAA than those without HS. Further research should consider clinical outcomes such as AAA rupture and associated mortality.
Neural substrate for the engagement of the ventral visual stream in motor control in the macaque monkey
Authors: Borra Elena , Gerbella Marzio , Rozzi Stefano , Luppino Giuseppe
Published: August 2024

The present study aimed to describe the cortical connectivity of a sector located in the ventral bank of the superior temporal sulcus in the macaque (intermediate area TEa and TEm [TEa/m]), which appears to represent the major source of output of the ventral visual stream outside the temporal lobe. The retrograde tracer wheat germ agglutinin was injected in the intermediate TEa/m in four macaque monkeys. The results showed that 58–78% of labeled cells were located within ventral visual stream areas other than the TE complex. Outside the ventral visual stream, there were connections with the memory-related medial temporal area 36 and the parahippocampal cortex, orbitofrontal areas involved in encoding subjective values of stimuli for action selection, and eye- or hand-movement related parietal (LIP, AIP, and SII), prefrontal (12r, 45A, and 45B) areas, and a hand-related dysgranular insula field. Altogether these data provide a solid substrate for the engagement of the ventral visual stream in large scale cortical networks for skeletomotor or oculomotor control. Accordingly, the role of the ventral visual stream could go beyond pure perceptual processes and could be also finalized to the neural mechanisms underlying the control of voluntary motor behavior.
Women’s Leadership in Fintech: Cross-Country Evidence
Authors: Khera Purva , Ogawa Sumiko , Sahay Ratna , Vasishth Mahima
Published: August 2024

This paper provides key insights into women’s representation in the fintech industry, and descriptively examines the association between female leadership and firm performance in this industry. Using novel data from fintech firms in over 80 countries, we find that women leaders in this industry remain scarce. Our analysis reveals that firms founded by women are associated with lower firm performance as measured by their estimated revenue and funding acquired, especially for small firms. On the other hand, there is a positive association between gender diversity in executive board and firm performance, especially for mid-to-large sized firms.