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Acta Metallurgica Sinica(English Letters) 2018年第12期31卷 1258-1264页

作者： Xiao-Pei Li song-zhu kure-chu Toru Ogasawara Hitoshi Yashiro Hai-Bo Wang Zi-Zhen Xu Xiao-Hui Li Guo-Lin song Guo-Yi Tang Advanced Materials Institute Graduate School at ShenzhenTsinghua University School of Materials Science and Engineering Tsinghua University Department of Chemistry and Bioengineering Iwate University

By using a novel surface modification technique named ultrasonic-electropulsing coupling rolling （UECR） process on an Al-Si casting alloy rod, the surface of material was smoothened significantly. Meanwhile, a strengthened layer with agradient change in hardness was obtained in the outer surface, corresponding to a homogeneous gradient nano-/micro-structure. The thickness of nanometer-thick laminated structures was at least 40 μm, which was much thicker thanconventional ultrasonic rolling process. During UECR, the formation of the well-defined nanocrystalline structure wasattributed to the high strain rate and simultaneous annealing process realized by ultrasonic impact and electropulsingtreatment.

关键词： Nanocrystalline materials Indentation and hardness Al-Si alloy Microstructure

Impacts of the annual cycle of background SST in the tropical Pacific on the phase and amplitude of ENSO

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Atmospheric and Oceanic Science Letters 2025年第1期18卷 12-17页

作者： song Jiang Congwen zhu Ning Jiang State Key Laboratory of Severe Weather(LASW) Chinese Academy of Meteorological SciencesBeijingChina College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijingChina

The dominant annual cycle of sea surface temperature(SST)in the tropical Pacific exhibits an antisymmetric mode,which explains 83.4%total variance,and serves as a background of El Niño-Southern Oscillation(ENSO).However,there is no consensus yet on its anomalous impacts on the phase and amplitude of *** on data during 1982-2022,results show that anomalies of the antisymmetric mode can affect the evolution of ENSO on the interannual scale via Bjerknes feedback,in which the positive(negative)phase of the antisymmetric mode can strengthen El Niño(La Niña)in boreal winter via an earlier(delayed)seasonal cycle transition and larger(smaller)annual *** magnitude of the SST anomalies in the equatorial eastern Pacific can reach more than±0.3◦C,regulated by the changes in the antisymmetric mode based on random sensitivity *** reveal the spatial pattern of the annual cycle associated with the seasonal phase-locking of ENSO evolution and provide new insight into the impact of the annual cycle of background SST on ENSO,which possibly carries important implications for forecasting ENSO.

关键词： Annual cycle SST anomaly Antisymmetric mode ENSO

基于多尺度融合金字塔焦点网络的接触网零部件检测

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工程科学学报 2025年第2期47卷 315-327页

作者：朱新宇崔浩锐宋洋中国民用航空飞行学院航空电子电气学院广汉618307 西南交通大学利兹学院成都611756

作为高铁牵引供电系统的重要组成部分,接触网系统承担着向动车组传输电能的重要功能.实际工程运营表明,受弓网交互产生的持续冲击以及外部环境的影响,接触网支撑部件可能会出现“松、脱、断、裂”等缺陷,导致接触网结构可靠性下降,严重... 详细信息

作为高铁牵引供电系统的重要组成部分,接触网系统承担着向动车组传输电能的重要功能.实际工程运营表明,受弓网交互产生的持续冲击以及外部环境的影响,接触网支撑部件可能会出现“松、脱、断、裂”等缺陷,导致接触网结构可靠性下降,严重影响接触网系统稳定运行.因此,及时精确定位接触网支撑部件(CSCs),对保障高铁安全运行和完善接触网检修维护策略具有重大意义.然而,CSCs的检测通常面临着零部件种类多、尺度差异大、部分零部件微小的问题.针对以上问题,本文提出一种基于多尺度融合金字塔焦点网络的接触网零部件检测算法,将平衡模块和特征金字塔模块相结合,提高对小目标的检测性能.首先,设计了可分离残差金字塔聚合模块(SRPAM),用于优化模型多尺度特征提取能力、扩大感受野,缓解CSCs检测的多尺度问题;其次,设计了一种基于平衡特征金字塔的路径聚合网络(PA-BFPN),用于提升跨层特征融合效率和小目标检测性能.最后,通过对比试验、可视化实验和消融实验证明了所提方法的有效性和优越性.其中,所提的MFPFCOS在CSCs数据集上的检测精度(mAP)能够在达到48.6%的同时,实现30的FLOPs(Floating point operations per second),表明所提方法能够在检测精度和检测速度之间保持良好的平衡.

关键词：深度学习目标检测接触网支撑组件(CSCs) 路径聚合特征金字塔(PA-FPN) 空洞空间卷积池化金字塔(ASPP)

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Explainable prediction of loan default based on machine learning models

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Data Science and Management 2023年第3期6卷 123-133页

作者： Xu zhu Qingyong chu Xinchang song Ping Hu Lu Peng School of Management Wuhan University of TechnologyWuhan430070China Research Institute of Digital Governance and Management Decision Innovation Wuhan University of TechnologyWuhan430070China

Owing to the convenience of online loans,an increasing number of people are borrowing money on online *** the emergence of machine learning technology,predicting loan defaults has become a popular ***,machine learning models have a black-box problem that cannot be *** make the prediction model rules more understandable and thereby increase the user’s faith in the model,an explanatory model must be *** regression,decision tree,XGBoost,and LightGBM models are employed to predict a loan *** prediction results show that LightGBM and XGBoost outperform logistic regression and decision tree models in terms of the predictive *** area under curve for LightGBM is *** accuracies of LightGBM and XGBoost exceed *** precisions of LightGBM and XGBoost exceed ***,we employed the local interpretable model-agnostic explanations approach to undertake an explainable analysis of the prediction *** results show that factors such as the loan term,loan grade,credit rating,and loan amount affect the predicted outcomes.

关键词： Explainable prediction Machine learning Loan default Local interpretable model-agnostic explanations

Optimal Fixed-Point Tracking Control for Discrete-Time Nonlinear Systems via ADP

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IEEE/CAA Journal of Automatica Sinica 2019年第3期6卷 657-666页

作者： Ruizhuo song Liao zhu IEEE the School of Automation and Electrical Engineering University of Science and Technology Beijing

Based on adaptive dynamic programming(ADP),the fixed-point tracking control problem is solved by a value iteration(VI) algorithm. First, a class of discrete-time(DT)nonlinear system with disturbance is considered. Second, the convergence of a VI algorithm is given. It is proven that the iterative cost function precisely converges to the optimal value,and the control input and disturbance input also converges to the optimal values. Third, a novel analysis pertaining to the range of the discount factor is presented, where the cost function serves as a Lyapunov function. Finally, neural networks(NNs) are employed to approximate the cost function, the control law, and the disturbance law. Simulation examples are given to illustrate the effective performance of the proposed method.

关键词： Adaptive dynamic programming (ADP) fixedpoint tracking optimal control

Forward-facing steps induced transition in a subsonic boundary layer

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Science China(Physics,Mechanics & Astronomy) 2017年第10期60卷 34-44页

作者： Hui zhu song Fu School of Aerospace Engineering Tsinghua University Beijing 100084 China

A forward-facing step (FFS) immersed in a subsonic boundary layer is studied through a high-order flux reconstruction (FR) method to highlight the flow transition induced by the step. The step height is a third of the local boundary-layer thickness. The Reynolds number based on the step height is 720. Inlet disturbances are introduced giving rise to streamwise vortices upstream of the step. It is observed that these small-scale streamwise structures interact with the step and hairpin vortices are quickly developed after the step leading to flow transition in the boundary layer.

关键词： forward-facing steps boundary layer transitional flow

Two-dimensional directional modulation with dual-mode vortex beam for security transmission

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Journal of Systems Engineering and Electronics 2022年第6期33卷 1108-1118页

作者： zhu Changju song Maozhong DANG Xiaoyu zhu Qiuming College of Electronic Information Engineering Nanjing University of Aeronautics and AstronauticsNanjing 211106China

A two-dimensional directional modulation(DM)technology with dual-mode orbital angular momentum(OAM)beam is proposed for physical-layer security of the relay unmanned aerial vehicle(UAV)tracking *** elevation and azimuth of the vortex beam are modulated into the *** can form the digital waveform with the encoding *** the signal is direction-dependent,the modulated waveform is purposely distorted in other directions to offer a security *** concentric uniform circular arrays(UCAs)with different radii are excited to generate dual vortex beams with orthogonality for the composite signal,which can increase the demodulation *** to the phase propagation characteristics of vortex beam,the constellation at the desired azimuth angle will change continuously within a wavelength.A desired single antenna receiver can use the propagation phase compensation and an opposite helical phase factor for the signal demodulation in the desired *** show that the proposed OAM-DM scheme offers a security approach with direction sensitivity transmission.

关键词： directional modulation(DM) orbital angular momentum(OAM) physical-layer security directional sensitivity

Low-temperature densification sintering and properties of CaAl_2Si_2O_8 ceramics with MeO·2B_2O_3(Me=Ca,Sr,Ba)

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International Journal of Minerals,Metallurgy and Materials 2015年第9期22卷 977-986页

作者： song Chen De-gui zhu School of Materials Science and Engineering Southwest Jiaotong University

Dense CaAl2Si2O8 ceramics were prepared via a two-step sintering process at temperatures below 1000℃. First, pre-sintered CaAl2Si2O8 powders containing small amounts of other crystal phases were obtained by sintering a mixture of calcium hydroxide and kaolin powders at 950℃ for 6 h. Subsequently, the combination of the pre-sintered ceramic powders with MeO＇2B203 （Me = Ca, Sr, Ba） flux agents enabled the low-temperature densification sintering of the CaAl2Si2O8 ceramics at 950℃. The sintering behavior and phase formation of the CaAl2Si2O8 ceramics were investigated in terms of the addition of the three MeO·2B2O3 flux agents. Furthermore, alumina and quartz were introduced into the three flux agents to investigate the sintering behaviors, phase evolvements, microstructures, and physical properties of the resulting CaA12Si208 ceramics. The results showed that, because of their low-melting characteristics, the MeO·2B2O3 （Me = Ca, Sr, Ba） flux agents facilitated the formation of the CaAl2Si2O8 ceramics with a dense microstructure via liquid-phase sintering. The addition of alumina and quartz to the flux agents also strongly affected the microstructures, phase formation, and physical properties of the CaA12Si208 ceramics.

关键词： ceramics densification sintering materials properties anorthite borates alumina quartz

Influence of sintering temperature on the phases and photoelectric characteristics of BiOCl/ZnO composite powders

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International Journal of Minerals,Metallurgy and Materials 2017年第12期24卷 1438-1447页

作者： song Chen De-gui zhu School of Materials Science and Engineering Southwest Jiaotong UniversityChengdu 610031China

Zinc oxide is a typical functional oxide that has been widely researched for various industry applications due to its peculiar physical characteristics. However, to achieve its potential in promising applications, much work has been diligently performed to improve the physical properties of ZnO. In this work, an aqueous suspension route was used to prepare BiOCl/ZnO composite powders, and sintering processes were applied to investigate the influence of sintering temperature on the phase evolutions, microstructures, and photoelectric characteristics of BiOCl/ZnO composite powders. The results indicated that the photoelectric properties mainly depend on the relevant content of BiOCl in the composite powders and the sintering temperature. The photoelectric measurements in K_2SO_4 solutions show that the photoelectric properties of the samples with the appropriate BiOCl content(0.3 mol% and 2.0 mol%) are better than those of ZnO and commercial TiO_2(P_(25)) powders, but the photoelectric measurements in NaOH solutions indicate that the photoelectric characteristics of the as-sintered samples are only better than those of P_(25).

关键词： ZnO/BiOCl composites sintering temperature microstructures photoelectric characteristics

Preparation of Ni2P/Al-SBA-15 catalyst and its performance for benzofuran hydrodeoxygenation

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Chinese Journal of Chemical Engineering 2017年第12期25卷 1784-1790页

作者： Tianhan zhu Hua song Xueya Dai Hualin song Provincial Key Laboratory of Oil & Gas Chemical Technology College of Chemistry & Chemical Engineering Northeast Petroleum University Daqing 163318 China Key Laboratory of Cancer Prevention and Treatment of Heilongjiang Province Mudanjiang Medical University Mudanjiang 157011 China

The Al-doped Ni2P/AI-SBA-15 catalyst with high hydrodeoxygenation （HDO） activity was synthesized by tem- perature programmed reduction at a relatively low reduction temperature of 400 ℃. The as-prepared catalyst was characterized by X-ray diffraction （XRD）, H2 temperature-programmed reduction （H2-TPR）, X-ray photoelectron spectroscopy （XPS）, transmission electron microscope （TEM）, NH3 temperature programmed desorption （NH3-TPD）, N2 adsorption-desorption and CO uptake. The effect of AI on benzofuran （BF） HDO performance was investigated. The result indicates that the incorporation of AI into the SBA-15 support can promote the formation of much uniform, smaller, highly dispersed N2P particles on the catalyst. The AI also contrib- utes to suppress the enrichment of P and promote more exposed Ni sites on the surface. In addition, the incorporation of AI can enhance the acid strength. The total deoxygenated product yield over Ni2P/AI-SBA-15 reached 90.3%, which is an increase of 19.4%, when compared with that found for Ni2P/SBA-15 （70.9%）.

关键词： Ni2P SBA-15 Hydrodeoxygenation Benzofuran AI