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Bearing Fault Diagnosis Based on Deep Discriminative Adversarial Domain Adaptation Neural Networks

Computer Modeling in Engineering & Sciences 2024年第3期138卷 2619-2640页

作者： Jinxi Guo Kai Chen jiehui liu Yuhao Ma Jie Wu Yaochun Wu Xiaofeng Xue Jianshen Li School of Mechanical and Equipment Engineering Hebei University of EngineeringHandan056000China College of Mechanical Engineering Anyang Institute of TechnologyAnyang455000China Department of Mechanical and Electrical Engineering Yuncheng UniversityYuncheng044000China

Intelligent diagnosis driven by big data for mechanical fault is an important means to ensure the safe operation ofequipment. In these methods, deep learning-based machinery fault diagnosis approaches have received increasingattention and achieved some results. It might lead to insufficient performance for using transfer learning alone andcause misclassification of target samples for domain bias when building deep models to learn domain-invariantfeatures. To address the above problems, a deep discriminative adversarial domain adaptation neural networkfor the bearing fault diagnosis model is proposed (DDADAN). In this method, the raw vibration data are firstlyconverted into frequency domain data by Fast Fourier Transform, and an improved deep convolutional neuralnetwork with wide first-layer kernels is used as a feature extractor to extract deep fault features. Then, domaininvariant features are learned from the fault data with correlation alignment-based domain adversarial ***, to enhance the discriminative property of features, discriminative feature learning is embeddedinto this network to make the features compact, as well as separable between classes within the class. Finally, theperformance and anti-noise capability of the proposedmethod are evaluated using two sets of bearing fault *** results demonstrate that the proposed method is capable of handling domain offset caused by differentworkingconditions and maintaining more than 97.53% accuracy on various transfer tasks. Furthermore, the proposedmethod can achieve high diagnostic accuracy under varying noise levels.

关键词： Fault diagnosis transfer learning domain adaptation discriminative feature learning correlation alignment

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Scheme of negative acoustic radiation force based on a multiple-layered spherical structure

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Chinese Physics B 2024年第1期33卷 477-487页

作者：宫门阳徐鑫乔玉配刘杰惠何爱军刘晓宙 Key Laboratory of Modern Acoustics Institute of Acoustics and School of PhysicsCollaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093China School of Physics and Electronic Science Guizhou Normal UniversityGuiyang 550001China School of Electronic Science and Engineering Nanjing UniversityNanjing 210023China State Key Laboratory of Acoustics Institute of AcousticsChinese Academy of SciencesBeijing 100190China

Acoustic radiation force(ARF), as an important particle manipulation method, has been extensively studied in recent years. With the introduction of the concept of “acoustic tweezers”, negative acoustic radiation has become a research hotspot. In this paper, a scheme of realizing negative ARF based on the multiple-layered spherical structure design is proposed. The specific structure and design idea are presented. Detailed theoretical calculation analysis is carried *** simulations have been performed to verify the correctness of this prediction. The conjecture that the suppression of backscattering can achieve negative ARF is verified concretely, which greatly expands the application prospect and design ideas of the ARF. This work has laid a theoretical foundation for realizing precise control of the structure.

关键词： acoustic tweezers negative acoustic radiation force particle manipulation

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Axial acoustic radiation force on a fluid sphere between two impedance boundaries for Gaussian beam

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Chinese Physics B 2019年第3期28卷 230-237页

作者： Yuchen Zang Yupei Qiao jiehui liu Xiaozhou liu Key Laboratory of Modern Acoustics Institute of Acoustics and School of PhysicsCollaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093China Key Laboratory of Acoustics Institute of AcousticsChinese Academy of SciencesBeijing 100190China

The acoustic radiation force on a fluid sphere immersed in water between two boundaries given by a Gaussian beam is theoretically and numerically investigated in this work. Based on the finite series method, the Gaussian beam is expressed in terms of Bessel function and a weighting parameter. The effects of the two boundaries concerned in our study is worked out by the image theory. This work also provides a reference when considering the effects of certain factors such as the radius of the sphere and the distance between the sphere and two boundaries. The contrast with the acoustic radiation force on a fluid sphere near only one boundary is also made in this paper. Our study can offer a theoretical basis for acoustics manipulation, acoustic sensors in the field of biomedical ultrasound and material science.

关键词： acoustic radiation force Gaussian beam fluid sphere impedance boundary

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Ultrasonic Scattered Field Distribution of One and Two Cylindrical Solids with Phased Array Technique

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Chinese Journal of Mechanical Engineering 2019年第6期32卷 101-112页

作者： Xiaozhou liu Jian Ma Haibin Wang Sha Gao Yifeng Li jiehui liu Key Laboratory of Modern Acoustics Institute of Acoustics and School of PhysicsNanjing UniversityNanjing 210093China College of Computer Science and Technology Nanjing University of TechnologyNanjing 211800China

The scattered fields of plane waves in a solid from a cylinder or sphere are critical in determining its acoustic characteristics as well as in engineering applications. This paper investigates the scattered field distributions of different incident waves created by elastic cylinders embedded in an elastic isotropic medium. Scattered waves, including longitudinal and transverse waves both inside and outside the cylinder, are described with specific modalities under an incident plane wave. A model with a scatterer embedded in a structural steel matrix and filled with aluminum is developed for comparison with the theoretical solution. The frequency of the plane wave ranged from 235 kHz to 2348 kHz, which corresponds to scaling factors from 0.5 to 5. Scattered field distributions in matrix materials blocked by an elastic cylindrical solid have been obtained by simulation or calculated using existing parameters. The simulation results are in good agreement with the theoretical solution, which supports the correctness of the simulation analysis. Furthermore, ultrasonic phased arrays are used to study scattered fields by changing the characteristics of the incident wave. On this foundation, a partial preliminary study of the scattered field distribution of double cylinders in a solid has been carried out, and the scattered field distribution at a given distance has been found to exhibit particular behaviors at different moments. Further studies on directivities and scattered fields are expected to improve the quantification of scattered images in isotropic solid materials by the phased array technique.

关键词： Ultrasonic phased array Scattered field distribution Directivity Quantification of scattered image

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Location of micro-cracks in plates using time reversed nonlinear Lamb waves

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Chinese Physics B 2020年第5期29卷 311-317页

作者： Yaoxin liu Aijun He jiehui liu Yiwei Mao Xiaozhou liu Key Laboratory of Modern Acoustics Institute of Acoustics and School of PhysicsNanjing UniversityNanjing 210093China Key Laboratory of Acoustics Institute of AcousticsChinese Academy of SciencesBeijing 100190China School of Electronic Science and Engineering Nanjing UniversityNanjing 210023China

A promising tool to detect micro-cracks in plate-like structures is used for generating higher harmonic Lamb *** this paper,a method combining nonlinear S0 mode Lamb waves with time reversal to locate micro-cracks is presented and verified by numerical *** different models,the contact acoustic nonlinearity(CAN)model and the Preisach-Mayergoyz(PM)model,are used to simulate a localized damage in a thin *** inversion method is employed to extract the second and fourth harmonics from the received *** reversal is performed to compensate the dispersion of S0 mode Lamb ***,the higher harmonics generated from the damaged area can be refocused on their *** investigating the spatial distribution of harmonic wave packets,the location of micro-cracks will be *** numerical simulations indicate that this method gives accurate locations of the damaged area in a ***,the PM model is proved to be a suitable model to simulate the micro-cracks in plates for generation of higher harmonics.

关键词： Lamb waves higher harmonics time reversal damage location

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Acoustic radiation force on a multilayered sphere in a Gaussian standing field

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Chinese Physics B 2018年第3期27卷 299-305页

作者： Haibin Wang Xiaozhou liu Sha Gao Jun Cui jiehui liu Aijun He Gutian Zhang Key Laboratory of Modern Acoustics Institute of AcousticsNanjing UniversityNanjing 210093China State Key Laboratory of Acoustics Institute of AcousticsChinese Academy of SciencesBeijing 100190China School of Electronic Science and Engineering Nanjing UniversityNanjing 210023China Nanjing Drum Tower Hospital The Affiliated Hospital of Nanjing University Medical SchoolNanjing 210093China

We develop a model for calculating the radiation force on spherically symmetric multilayered particles based on the acoustic scattering *** expression is derived for the radiation force on a multilayered sphere centered on the axis of a Gaussian standing wave propagating in an ideal fluid,The effects of the sound absorption of the materials and sound wave on acoustic radiation force of a multilayered sphere immersed in water are analyzed,with particular emphasis on the shell thickness of every layer,and the width of the Gaussian *** results reveal that the existence of particle trapping behavior depends on the choice of the non-dimensional frequency ka,as well as the shell thickness of each *** study provides a theoretical basis for the development of acoustical tweezers in a Gaussian standing wave,which may benefit the improvement and development of acoustic control technology,such as trapping,sorting,and assembling a cell,and drug delivery applications.

关键词： acoustic radiation force Gaussian standing field multilayered sphere model sound scattering

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贝莱斯芽胞杆菌LQ-3防治小麦纹枯病的效果及根际定殖能力

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麦类作物学报 2024年第7期44卷 947-954页

作者：李蓉洪赫姜文筱王艳斌张红娟赵芳刘杰辉张泽梁艳王春静谢咸升山西农业大学小麦研究所山西临汾041000 中国农业大学植物保护学院北京100193

小麦纹枯病(wheat sharp eyespot)主要是由禾谷丝核菌(Rhizoctonia cerealis)侵染引起的一种土传真菌病害,严重威胁小麦生产安全。目前,利用生防细菌防治小麦纹枯病已成为研究热点,其中,研究最多的一类生防细菌为芽胞杆菌。为明确贝莱... 详细信息

小麦纹枯病(wheat sharp eyespot)主要是由禾谷丝核菌(Rhizoctonia cerealis)侵染引起的一种土传真菌病害,严重威胁小麦生产安全。目前,利用生防细菌防治小麦纹枯病已成为研究热点,其中,研究最多的一类生防细菌为芽胞杆菌。为明确贝莱斯芽胞杆菌(Bacillus velezensis)LQ-3防治小麦纹枯病的效果及其在小麦根部定殖能力,本研究利用LQ-3发酵液灌根处理小麦苗,调查统计LQ-3对小麦纹枯病的防效。同时利用绿色荧光蛋白标记菌株LQ-3(pGFP78)灌根处理小麦根部,并结合抗生素平板回收检测、激光共聚焦显微镜观察方法,探明LQ-3在小麦根部的定殖动态。结果表明,LQ-3防治小麦纹枯病的效果为57.49%,与化学药剂27%苯醚·咯·噻虫悬浮种衣剂(酷拉斯)的防效(59.95%)相当。LQ-3(pGFP78)的生长趋势与野生型LQ-3相比并没有显著性差异,且仍具有游动性和生物膜形成能力。LQ-3(pGFP78)发酵液初始浓度为2.3×10^(8) cfu·mL^(-1),灌根处理5 d后,其在小麦根部的定殖量已达到9.63×10^(6)cfu·g^(-1),25 d后,定殖量仍有1.33×10^(6)cfu·g^(-1),表明LQ-3在小麦根部具有较好的定殖能力。

关键词：贝莱斯芽胞杆菌LQ-3 小麦纹枯病定殖防效

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河北省农业生态旅游空间格局分析

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中国农业资源与区划 2019年第7期40卷 227-232页

作者：刘洁卉河北能源职业技术学院

[目的]发展农业生态旅游是促进农民增收,建设社会主义新农村,加快城乡一体化进程的重要举措。研究农业生态旅游资源的空间分布,对今后合理优化农业生态旅游布点提供理论参考。[方法]采用平均最邻近比率、地理集中指数和平均分布密度3个... 详细信息

[目的]发展农业生态旅游是促进农民增收,建设社会主义新农村,加快城乡一体化进程的重要举措。研究农业生态旅游资源的空间分布,对今后合理优化农业生态旅游布点提供理论参考。[方法]采用平均最邻近比率、地理集中指数和平均分布密度3个指标来分析河北省农业生态旅游空间格局分布特征,并对影响因素进行了探究。[结果](1)河北省农业生态旅游资源总体呈集聚分布,主要分布于河北省中南部和东北部地区。(2)从各地级市农业生态旅游资源的分布数目看,邢台市农业生态旅游资源的个数最多,为38个,占总数的19.68%。其次是保定市,为28个,占总数的14.51%。沧州市农业生态旅游资源的数目最少,仅为6个,占总数的3.11%。(3)各地级市中,邢台市和秦皇岛市的农业生态旅游资源平均分布密度远高于其他地区,分别为30.43个/万km~2和24.32个/万km~2。沧州、承德和张家口的分布密度较低,分别为4.47个/万km~2、3.04个/万km~2和4.17个/万km~2。(4)经济发展水平、交通条件和资源禀赋是影响河北省农业生态旅游资源分布的主要因素。[结论]该省农业生态旅游资源市域分布不均匀,各地市间发展极不平衡。今后,一方面加大交通设施建设,增加发展农业生态旅游的可能性。另一方面,发挥当地农业资源和旅游资源优势,逐步缩短地区差异。

关键词：农业生态旅游新农村建设空间格局缩短差距河北省

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抚养权争议中实现未成年人利益最大化之探讨

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法律适用 2021年第11期 101-110页

作者：刘杰晖广东省深圳市中级人民法院民事审判庭

民法典确立了解决抚养争议的最有利于未成年子女原则,《最高人民法院关于加强新时代未成年人审判工作的意见》指出要全面加强未成年人权益司法保护,坚持未成年人利益最大化原则。应以司法的灵活性和对社会生活的回应性,提炼出类案适用规... 详细信息

民法典确立了解决抚养争议的最有利于未成年子女原则,《最高人民法院关于加强新时代未成年人审判工作的意见》指出要全面加强未成年人权益司法保护,坚持未成年人利益最大化原则。应以司法的灵活性和对社会生活的回应性,提炼出类案适用规则,明确解决思路与方法,有效弥补具体裁判规则的不足。应着重解决探望问题;重视8周岁以上未成年人的意愿,同时应考察意愿形成的原因与背景;对改变子女生活环境的,应当考察对子女利益的影响;不应过多追究过去的争执与冲突;一方的职业、接受的教育背景、经济条件等因素不是确定直接抚养权的唯一依据。隔代辅助抚养是否作为优先考虑因素的关键是隔代亲子关系是否有利子女身心健康。在争议解决过程中做出临时解决的程序安排,丰富社会调查报告内容,是实现未成年人利益最大化的有效路径。

关键词：抚养权探望未成年人利益最大化

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论测谎结果的证据效力及其规范

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政治与法律 2006年第6期 125-129页

作者：刘洁辉河南周口师范学院政法系河南周口466000

测谎仪即多参量心理测试仪所获得测试结果具有客观性和与案件的关联性的特征,也具备证据的合法性要求,是符合我国刑事诉讼法对证据的基本要求的。在证据效力上,测谎结果不能作为独立的证据,测谎结果须经过审慎的检查并与其他证据一起,... 详细信息

测谎仪即多参量心理测试仪所获得测试结果具有客观性和与案件的关联性的特征,也具备证据的合法性要求,是符合我国刑事诉讼法对证据的基本要求的。在证据效力上,测谎结果不能作为独立的证据,测谎结果须经过审慎的检查并与其他证据一起,揭示、反映案件的事实。测谎结果的公正性和合法性完全可以通过对测谎程序的完善和规范来加以保障,具体要明确测试人员的资格与诉讼地位;确立决定测谎检查的一般原则和具体条件;制定科学的操作程序与规则。

关键词：测谎证据能力刑事诉讼测谎仪滥用

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