AIP Advances最新文献_第10页

Effect of driving current profile on acceleration efficiency of electromagnetic railgun 驱动电流曲线对电磁轨道炮加速效率的影响

IF 1.6 4区物理与天体物理

AIP Advances Pub Date : 2024-08-08 DOI: 10.1063/5.0214320

Dipjyoti Balo Majumder, Rishi Verma, J. M. V. V. S. Aravind, J. N. Rao, Manraj Meena, Lakshman Rao Rongali, Bijayalaxmi Sethi, Archana Sharma

{"title":"Effect of driving current profile on acceleration efficiency of electromagnetic railgun","authors":"Dipjyoti Balo Majumder, Rishi Verma, J. M. V. V. S. Aravind, J. N. Rao, Manraj Meena, Lakshman Rao Rongali, Bijayalaxmi Sethi, Archana Sharma","doi":"10.1063/5.0214320","DOIUrl":"https://doi.org/10.1063/5.0214320","url":null,"abstract":"In this paper, the effect of driving current profile on efficient utilization and conversion of stored electrical energy into kinetic energy of the projectile has been investigated for electromagnetic railgun systems. It has been experimentally evidenced and also corroborated by simulation results that the acceleration efficiency of railgun launcher is much higher for the case when the driving current feed has an over-damped unidirectional profile vs the case when an under-damped sinusoidal current of same amplitude is fed. To analyze this effect, a mathematical model has been developed incorporating dynamic resistance scaling and velocity dependent frictional effects. For the typical case of projectile weighing ∼8 g and input driving current amplitude of ∼220 kA, the estimated average force from the mathematical model simulation acting on the armature projectile increases from 1.4 to 3.83 kN, consequently resulting in an increase in velocity from 489 to 931 m/s and overall efficiency from 0.55% to 2% for the sinusoidal and unidirectional current profiles, respectively. Experimentally, a maximum velocity of ∼1024 m/s was obtained when a unidirectional over-damped current of similar amplitude was fed using a pulse shaping inductor in conjunction with a crowbar switch. The obtained experimental results of trials with different masses of armatures complement the results of the conceived mathematical model used in simulations. The marginal underestimation of the simulated velocity is due to the inevitable lacking in precise estimation of the frictional force and mass loss that dynamically occur in the projectile during acceleration.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141943495","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Optimal energy scheduling for microgrid based on GAIL with Wasserstein distance 基于 GAIL 和 Wasserstein 距离的微电网优化能源调度

IF 1.6 4区物理与天体物理

AIP Advances Pub Date : 2024-08-08 DOI: 10.1063/5.0207444

Kuo Wang, Zhanqiang Zhang, Keqilao Meng, Pengbing Lei, Rui Wang, Wenlu Yang, Zhihua Lin

{"title":"Optimal energy scheduling for microgrid based on GAIL with Wasserstein distance","authors":"Kuo Wang, Zhanqiang Zhang, Keqilao Meng, Pengbing Lei, Rui Wang, Wenlu Yang, Zhihua Lin","doi":"10.1063/5.0207444","DOIUrl":"https://doi.org/10.1063/5.0207444","url":null,"abstract":"Owing to the volatility and intermittency of renewable energy generation units in microgrids, effective energy scheduling methods are essential for efficient renewable energy utilization and stable microgrid operation. In recent years, microgrid energy optimization scheduling based on deep reinforcement learning (DRL) has made significant progress. With the development of the microgrid, the drawbacks of the traditional DRL agent, such as long training time and poor convergence effect, are gradually revealed. This paper proposes a generative adversarial imitation learning method with Wasserstein distance for optimal energy scheduling in the microgrid. This method combines a proximal policy optimization algorithm to optimize energy scheduling and reduce microgrid operating costs. First, the agent adaptively learns the action exploration process by imitating expert trajectories. Second, based on the generative adversarial theory, a discriminator network is added, and the Wasserstein distance is introduced into the discriminator network to distinguish between the generative and expert strategies. This feedback assists in updating the neural network parameters. Finally, the effectiveness of the proposed method is verified through an arithmetic example analysis.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141943493","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Contributions to the isothermal compressibility coefficient of water near the temperature of 42 °C 水在温度 42 °C 附近的等温压缩系数的贡献

IF 1.6 4区物理与天体物理

AIP Advances Pub Date : 2024-08-08 DOI: 10.1063/5.0205612

Leonid A. Bulavin, Yevgenii G. Rudnikov, Alexander V. Chalyi

{"title":"Contributions to the isothermal compressibility coefficient of water near the temperature of 42 °C","authors":"Leonid A. Bulavin, Yevgenii G. Rudnikov, Alexander V. Chalyi","doi":"10.1063/5.0205612","DOIUrl":"https://doi.org/10.1063/5.0205612","url":null,"abstract":"Using modern databases, the behavior of the isothermal compressibility coefficient −(∂V/∂P)T = VβT of water in the liquid state near its specific temperature of θ = 42.2 ± 0.2 °C was analyzed. The applicability of the principle of corresponding states in a wide range of thermodynamic parameters of water has been confirmed, excluding the area of water anomalies. The following anomalies of the physical–chemical properties of water were observed: (a) the temperature of θ = 42.2 ± 0.2 °C was found at which the entropy contribution to the isothermal compressibility coefficient of water changed its sign and became positive below this temperature; (b) the temperature of θ = 28.8 ± 0.2 °C was found at which the energy contribution to the isothermal compressibility coefficient of water changed its sign and became negative below this temperature; and (c) the temperature of θ = 17.6 ± 0.2 °C was found at which the energy and entropy contributions to the isothermal compressibility coefficient of water were equal. The entropy contribution to the isothermal compressibility coefficient, according to the two-structure model of water, can be associated with the existence of an “expanded” low-density water structure of hydrogen bonds, the role of which increases with decreasing temperature. We associate the energy contribution to the isothermal compressibility coefficient with the “collapsed” high-density water structure of hydrogen bonds, the role of which in the field of thermodynamic anomalies of water decreases as the temperature decreases.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141943494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Simulation study on the influence of initial density distribution of laser ionized plasma on the ion extraction characteristics 激光电离等离子体初始密度分布对离子萃取特性影响的模拟研究

IF 1.6 4区物理与天体物理

AIP Advances Pub Date : 2024-08-08 DOI: 10.1063/5.0206433

Xing Chen, Xiao-Yong Lu, Lu Cai

{"title":"Simulation study on the influence of initial density distribution of laser ionized plasma on the ion extraction characteristics","authors":"Xing Chen, Xiao-Yong Lu, Lu Cai","doi":"10.1063/5.0206433","DOIUrl":"https://doi.org/10.1063/5.0206433","url":null,"abstract":"In isotope concentration technology, ion extraction current and ion extraction efficiency are the key factors to measure the efficiency of the isotope concentration. In order to increase the ion extraction current, researchers usually hope to produce a plasma source with large initial peak density and width; however, in reality, it is limited by the laser power, and the total number of ions in a plasma produced by laser ionization is almost certain. In this case, how to improve the ion extraction efficiency by choosing the appropriate initial density distribution of plasma has become a difficult problem. In this paper, the effects of the initial density distribution of plasma on the ion extraction characteristics are studied by using the electron equilibrium fluid model. The numerical results suggest that the ion extraction efficiency is independent of the initial density distribution of plasma while the total number of ions in the plasma, the distance between the electrodes, and the electric field intensity are kept constant. When the total number of ions and the electric field intensity are kept constant, the distance between the electrodes is shortened by one time, and the time of ion extraction is also shortened by nearly one time; thus, the plasma source with high initial peak density and small width can be chosen, and the aim of ion extraction can be achieved by shortening the distance between the electrodes. This research results provide an important reference for guiding the experimental parameters such as laser power distribution and the design of ion extraction device.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141943284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A new bilevel algorithm for UUV global path planning 用于 UUV 全局路径规划的新型双级算法

IF 1.6 4区物理与天体物理

AIP Advances Pub Date : 2024-08-08 DOI: 10.1063/5.0207107

Xin Pan, Guoli Feng, Lin Huang, Haiyan Zeng

{"title":"A new bilevel algorithm for UUV global path planning","authors":"Xin Pan, Guoli Feng, Lin Huang, Haiyan Zeng","doi":"10.1063/5.0207107","DOIUrl":"https://doi.org/10.1063/5.0207107","url":null,"abstract":"Global path planning is one of the key technologies in unmanned underwater vehicle (UUV) intelligent control. At present, research on UUV global path planning technology tends to choose long-distance and large-scale 3D space as the research environment, which leads to a sharp increase in the amount of data and search range for 3D spatial path planning. Therefore, an efficient and relatively small data volume 3D spatial path planning method is an urgent problem that needs to be solved for UUV engineering applications. To solve this problem, a new bilevel path planning algorithm for UUV is proposed. In the upper level of the algorithm, a Max Min Ant System-Elite Genetic (MMAS-EGA) algorithm is put forward, which is a hybrid ant colony optimization/genetic algorithm, in order to improve the convergence speed of the algorithm. In the lower level of the bilevel algorithm, a function optimization algorithm and the MMAS algorithm are used to minimize the number of variables to be optimized. To verify the effectiveness of the algorithm, we conducted simulation experiments in a three dimensional environment. The simulation results in the three-dimensional environment show that, compared with the existing bilevel algorithm, the time to search the global optimal solution is reduced by 9%, and the number of iterations is reduced by 4.4%. Furthermore, the new algorithm we proposed is more efficient and suitable for global path planning for different tasks.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141943288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Analysis of the impact of electromagnetic fields on UAV flight control systems in EHV–UHV DC overhead transmission lines 超高压-超高压直流架空输电线路中电磁场对无人机飞行控制系统的影响分析

IF 1.6 4区物理与天体物理

AIP Advances Pub Date : 2024-08-08 DOI: 10.1063/5.0225258

Jie Li, Lingkai Kong, Minghao Chu

{"title":"Analysis of the impact of electromagnetic fields on UAV flight control systems in EHV–UHV DC overhead transmission lines","authors":"Jie Li, Lingkai Kong, Minghao Chu","doi":"10.1063/5.0225258","DOIUrl":"https://doi.org/10.1063/5.0225258","url":null,"abstract":"The impact of operating voltage on Unmanned Aerial Vehicle (UAV) inspection and control is mainly manifested as electromagnetic interference, where the electric field mainly affects the distribution of space charges and ions, exhibiting adsorption effects on UAVs, and the magnetic field interferes with airborne magnetometers, disrupting the navigation system of UAVs. Under power frequency conditions, the electromagnetic field of alternating current exhibits alternating characteristics, and it only polarizes near the wire to form space charges or ion currents, with little effect at further distances. However, the variation in the magnetic field in one cycle is zero (positively correlated with alternating current), so its impact on UAVs is not particularly significant. Under direct current conditions, a constant current is introduced into the wire, and the electric field polarized around the wire generates a constant property of charge or ion current, resulting in a relatively larger electric field strength and a wider range of influence. At the same time, the constant current generates a constant magnetic field, which is applied to the airborne magnetometer, equivalent to adding a constant interference source, thus having a significant impact on the inspection and control of UAVs. This article uses ANSYS software to conduct electromagnetic field simulation analysis on DC transmission lines of different voltage levels.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141943303","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Research on rolling bearing fault diagnosis technology based on singular value decomposition 基于奇异值分解的滚动轴承故障诊断技术研究

IF 1.6 4区物理与天体物理

AIP Advances Pub Date : 2024-08-07 DOI: 10.1063/5.0225222

Jingfang Ji, Jingmin Ge

{"title":"Research on rolling bearing fault diagnosis technology based on singular value decomposition","authors":"Jingfang Ji, Jingmin Ge","doi":"10.1063/5.0225222","DOIUrl":"https://doi.org/10.1063/5.0225222","url":null,"abstract":"To solve the difficulty of selecting the number of effective singular values in Singular Value Decomposition denoising, a new method to determine the number of effective singular values is proposed. The proposed method to determine the number of effective singular values is based on the non-zero singular value distribution law of the Hankel matrix constructed by the signal. Specifically, the number of effective singular values in the Hankel matrix is twice the number of frequencies contained in the signal, and the difference between the effective singular values of the noisy signal and the non-zero singular values of the pure signal is very small. The proposed method for determining the number of effective singular values is to perform differential processing on the singular values of the signal and normalize the difference obtained. An empirical parameter T is provided, and the number of effective singular values is determined by comparing them with the normalized results. The proposed method is applied to the simulated and measured rolling bearing signals, and the results are compared with the wavelet threshold denoising method. The results show that the proposed method for determining the number of singular values can effectively filter out the noise frequency contained in the signal while maintaining the characteristic frequency of the signal and achieving the purpose of mechanical equipment fault diagnosis.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141943289","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

NeuroRoots, a bio-inspired, seamless brain machine interface for long-term recording in delicate brain regions. 神经根（NeuroRoots）是一种受生物启发的无缝脑机接口，用于在精细脑区进行长期记录。

IF 1.4 4区物理与天体物理

AIP Advances Pub Date : 2024-08-07 eCollection Date: 2024-08-01 DOI: 10.1063/5.0216979

Marc D Ferro, Christopher M Proctor, Alexander Gonzalez, Sriram Jayabal, Eric Zhao, Maxwell Gagnon, Andrea Slézia, Jolien Pas, Gerwin Dijk, Mary J Donahue, Adam Williamson, Jennifer Raymond, George G Malliaras, Lisa Giocomo, Nicholas A Melosh

{"title":"NeuroRoots, a bio-inspired, seamless brain machine interface for long-term recording in delicate brain regions.","authors":"Marc D Ferro, Christopher M Proctor, Alexander Gonzalez, Sriram Jayabal, Eric Zhao, Maxwell Gagnon, Andrea Slézia, Jolien Pas, Gerwin Dijk, Mary J Donahue, Adam Williamson, Jennifer Raymond, George G Malliaras, Lisa Giocomo, Nicholas A Melosh","doi":"10.1063/5.0216979","DOIUrl":"10.1063/5.0216979","url":null,"abstract":"Scalable electronic brain implants with long-term stability and low biological perturbation are crucial technologies for high-quality brain-machine interfaces that can seamlessly access delicate and hard-to-reach regions of the brain. Here, we created \"NeuroRoots,\" a biomimetic multi-channel implant with similar dimensions (7 μm wide and 1.5 μm thick), mechanical compliance, and spatial distribution as axons in the brain. Unlike planar shank implants, these devices consist of a number of individual electrode \"roots,\" each tendril independent from the other. A simple microscale delivery approach based on commercially available apparatus minimally perturbs existing neural architectures during surgery. NeuroRoots enables high density single unit recording from the cerebellum in vitro and in vivo. NeuroRoots also reliably recorded action potentials in various brain regions for at least 7 weeks during behavioral experiments in freely-moving rats, without adjustment of electrode position. This minimally invasive axon-like implant design is an important step toward improving the integration and stability of brain-machine interfacing.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11309783/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141915849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Inhibiting the imprint effect of the TiN/HZO/TiN ferroelectric capacitor by introducing a protective HfO2 layer 通过引入 HfO2 保护层抑制 TiN/HZO/TiN 铁电电容器的压印效应

IF 1.6 4区物理与天体物理

AIP Advances Pub Date : 2024-08-07 DOI: 10.1063/5.0222725

Shihao Yu, Yefan Zhang, Peng Yang, Xiaopeng Luo, Zhenyuan Sun, Haijun Liu, Sen Liu

引用次数: 0

Fitting COVID-19 datasets to a new statistical model 用新的统计模型拟合 COVID-19 数据集

IF 1.6 4区物理与天体物理

AIP Advances Pub Date : 2024-08-07 DOI: 10.1063/5.0214473

Ahmed M. Gemeay, Yusra A. Tashkandy, M. E. Bakr, Anoop Kumar, Md. Moyazzem Hossain, Ehab M. Almetwally

{"title":"Fitting COVID-19 datasets to a new statistical model","authors":"Ahmed M. Gemeay, Yusra A. Tashkandy, M. E. Bakr, Anoop Kumar, Md. Moyazzem Hossain, Ehab M. Almetwally","doi":"10.1063/5.0214473","DOIUrl":"https://doi.org/10.1063/5.0214473","url":null,"abstract":"This paper discussed gull alpha power Weibull distribution with a three-parameter. Different statistical inference methods of Gull Alpha Power Weibull distribution parameters have been obtained, estimated, and evaluated. Then, the results are compared to find a suitable model. The unknown parameters of the published Gull Alpha Power Weibull distribution are analyzed. Seven estimation methods are maximum likelihood, Anderson–Darling, right-tail Anderson–Darling, Cramér–von Mises, ordinary least-squares, weighted least-squares, and maximum product of spacing. In addition, the performance of this distribution is computed using the Monte Carlo method, and the limited sample features of parameter estimates for the proposed distribution are analyzed. In light of the importance of heavy-tailed distributions, actuarial approaches are employed. Applying actuarial criteria such as value at risk and tail value at risk to the suggested distribution shows that the model under study has a larger tail than the Weibull distribution. Two real-world COVID-19 infection datasets are used to evaluate the distribution. We analyze the existence and uniqueness of the log-probability roots to establish that they represent the global maximum. We conclude by summarizing the outcomes reported in this study.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141943287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0