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多元合金铁基堆焊层的回火稳定性

物理测试 2006年第4期24卷 12-14页

作者：王洪海马焕明秦皇岛市戴卡轮毂制造有限公司河北秦皇岛066003

对多元合金铁基堆焊层的焊态试样进行不同条件下的回火后处理,研究了该堆焊层的回火稳定性。结果表明,多元合金铁基堆焊层经560℃保温4 h回火后,堆焊层硬度达HRC 57;经700℃17℃急冷急热重复循环150次后,堆焊层硬度达HRC 43,具有较高的... 详细信息

对多元合金铁基堆焊层的焊态试样进行不同条件下的回火后处理,研究了该堆焊层的回火稳定性。结果表明,多元合金铁基堆焊层经560℃保温4 h回火后,堆焊层硬度达HRC 57;经700℃17℃急冷急热重复循环150次后,堆焊层硬度达HRC 43,具有较高的回火稳定性及“二次硬化”现象。

关键词：铁基堆焊层回火稳定性多元合金

A general end-to-end diagnosis framework for manufacturing systems

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National Science Review 2020年第2期7卷 418-429页

作者： Ye Yuan Guijun ma Cheng Cheng Beitong Zhou huan Zhao hai-Tao Zhang Han Ding School of Artificial Intelligence and Automation MOE Key Lab of Intelligent Control and Image Processing Huazhong University of Science and Technology State Key Laboratory of Digital manufacturing Equipment and Technology Huazhong University of Science and Technology School of Mechanical Science and Engineering Huazhong University of Science and Technology

The manufacturing sector is envisioned to be heavily influenced by artificial-intelligence-based technologies with the extraordinary increases in computational power and data volumes. A central challenge in the manufacturing sector lies in the requirement of a general framework to ensure satisfied diagnosis and monitoring performances in different manufacturing applications. Here, we propose a general data-driven,end-to-end framework for the monitoring of manufacturing systems. This framework, derived from deep-learning techniques, evaluates fused sensory measurements to detect and even predict faults and wearing conditions. This work exploits the predictive power of deep learning to automatically extract hidden degradation features from noisy, time-course data. We have experimented the proposed framework on 10 representative data sets drawn from a wide variety of manufacturing applications. Results reveal that the framework performs well in examined benchmark applications and can be applied in diverse contexts,indicating its potential use as a critical cornerstone in smart manufacturing.

关键词： manufacturing systems deep learning diagnosis and monitoring

Limit behaviors for dependent Bernoulli variables

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Applied mathematics(A Journal of Chinese Universities) 2020年第4期35卷 399-409页

作者： MIAO Yu ma huan-huan College of mathematics and Information Science Henan Normal UniversityXinxiang 453007China

In this paper,we consider a class of dependent Bernoulli variables,which has the following form:for k≥m,P(Xk+1=1jFk)=Σm i=1θiXk+1􀀀i+θ0p,where m is a positive integer,Σmi=0θi=1,Fn=σ{X1,……,Xn},0 详细信息

关键词： strong law of large numbers moderate deviation Bernoulli variables martingale

Rh2O3/hexagonal CePO4 nanocatalysts for N2O decomposition

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Frontiers of Chemical Science and Engineering 2017年第4期11卷 586-593页

作者： huan Liu Zhen ma Shanghai Key Laboratory of Atmospheric Particle Pollution & Prevention (LAP3) Department of Environmental Science & Engineering Fudan University Shanghai 200433 China

Hexagonal CePO4 nanorods were prepared by a precipitation method and hexagonal CePO4 nanowires were prepared by hydrothermal synthesis at 150 ℃. Rh （NO3）3 was then used as a precursor for the impregnation of Rh203 onto these CePO4 materials. The Rh203 supported on the CePO4 nanowires was much more active for the catalytic decomposition of N20 than the RhzO3 supported on CePO4 nanorods. The stability of both catalysts as a function of time on stream was studied and the influence of the co-feed （CO2, O2, H20 or O2/H20） on the N20 decomposition was also investigated. The samples were characterized by N2 adsorption-desorption, induc- tively coupled plasma optical emission spectroscopy, X- ray diffraction, transmission electron microscopy, X-ray photoelectron microscopy, hydrogen temperature-pro- grammed reduction, oxygen temperature-programmed desorption, and CO2 temperature-programmed desorption in order to correlate the physicochemical and catalytic properties.

关键词： Rh2O3 CePO4 N2O decomposition

Rh_2O_3/monoclinic CePO_4 composite catalysts for N_2O decomposition and CO oxidation

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Chinese Journal of Chemical Engineering 2018年第1期26卷 109-115页

作者： huan Liu Zhen ma Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention Department of Environmental Science and EngineeringFudan University

CePO4 （in particular, monoclinic CePO4） has been rarely used to make supported catalysts. Herein, monoclinic CeP04 nanoparticles were prepared by calcining hexagonal CePO4 nanomds （prepared by precipitation） in air at 900 ℃. Monoclinic CePO4 nanowires were prepared by calcining hexagonal CePO4 nanowires （prepared by hydrothermal synthesis at 150 ℃） in air at 900 ℃. Both monoclinic CePO4 materials were used to support Rh2O3 by impregnation using Rh（NO3）3 as a precursor （followed by calcination）. The catalytic performance of Rh2O3/monoclinic CePO4 composite materials in N2O decomposition and CO oxidation was investigated. It was found that Rh2O3 supported on monoclinic CePO4 nanowims was much more active than Rh2O3 supported on monoclinic CePO4 nanoparticles. The stability of catalysts as a function of reaction time on stream was studied in both reactions. The influence of co-fed CO2, O2, and H2O on the catalytic activity in N20 decomposition was also studied. These catalysts were characterized by employing N2 adsorption-desorption, ICP-OES, XRD, TEM, XPS, H2-TPR, O2-TPD, and CO2-TPD. The correlation between physicochemical properties and catalytic properties was discussed.

关键词： Rh2O3 CePO4 N2O decomposition CO oxidation Catalyst

Cerium phosphate-supported Au catalysts for CO oxidation

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Chinese Journal of Chemical Engineering 2018年第10期26卷 2055-2063页

作者： Yulin Wang huan Liu Zhen ma Shanghai Key Lahoratory of Atmospheric Particle Pollution & Prevention ( IAP^3 ) Department of Environmental Sdence & Engineering Fudan University Shanghai 200433 China

LaPO_4 and hydroxyapatite(Ca_(10)(PO_4)_6(OH)_2)are typical metal phosphates recently found to be useful for making supported metal or metal oxide catalysts,but CePO_4(also belonging to the metal phosphate family)has been rarely used to make supported *** would be interesting to develop CePO_4-supported catalysts and explore their catalytic ***,hexagonal CePO_4 nanorods(denoted as CePO_4-H),hexagonal CePO_4 nanowires(CePO_4-HNW),monoclinic CePO_4 nanoparticles(CePO_4-M),and monoclinic CePO_4 nanowires(CePO_4-MNW)prepared by different methods were used to support gold via deposition-precipitation with urea(DPU).The gold contents of these catalysts were all around 1 wt%.The catalytic activities of these Au/CePO_4 catalysts in CO oxidation were found to follow the sequence of Au/CePO_4-MNW>Au/CePO_4-HNW> Au/CePO_4-M>Au/CePO_*** catalysts were characterized by inductively coupled plasma-optical emission spectroscopy(ICP-OES),N_2 adsorption–desorption,X-ray diffraction(XRD),transmission electron microscopy(TEM),X-ray photoelectron spectroscopy(XPS),oxygen temperature-programmed desorption(O_2-TPD),and CO_2 temperature-programmed desorption(CO_2-TPD)to find possible correlations between the physicochemical properties and catalytic activities of these catalysts.

关键词： Gold Catalysis Catalyst support CePO4 Carbon monoxide Oxidation

A Taint Analysis Framework Applied to Android Applications in the Packed State

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China Communications 2023年第3期20卷 336-346页

作者： Shouying Bai Lu ma huan ma Wei Liu National Computer Network Emergency Response Technical Team/Coordination Center of China Beijing 100029China

In recent years,Android applications have caused personal privacy leaks *** order to analyze the malicious behavior,taint analysis technology can be used to track the API call chain,build a control-flow graph of function,and determine whether there is a security ***,with the continuous escalation of offensive and defensive confrontation of source code,more and more applications use reinforcement technology to prevent security practitioners from performing reverse analysis,therefore it is impossible to analyze function-behavior from the source ***,we design a framework of taint analysis that applied to the Android applications,which automatically unpacks the Android APKs,restores the real source code of the App,performs taint analysis,and generates a control-flow graph of *** tests showed that the system can cope with the current mainstream reinforcement technology and restore the real Dex file ***,compared with the number of nodes before packing,the generated control-flow graph had an explosive increase,which effectively assisted manual analysis of App with the privacy leakage behaviors.

关键词： privacy disclosure unpacked technology taint analysis

Study of a background reconstruction method for the measurement of D-meson azimuthal angular correlations

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Nuclear Science and Techniques 2021年第6期32卷 63-69页

作者： Long ma Xin Dong huan-Zhong huang Yu-Gang ma Key Laboratory of Nuclear Physics and Ion-beam Application(MOE) Institute of Modern PhysicsFudan University200433 ShanghaiChina Nuclear Science Division Lawrence Berkeley National LaboratoryBerkeleyCA 94720USA University of California Los AngelesCalifornia 90095USA

We studied experimental background reconstruction methods for the measurement of the D-D correlation using PYTHIA *** like-sign(LS)and side-band(SB)background methods,which are widely used in the experimental measurements of single D-meson production yields,were deployed for correlation *** was found that the LS method,which describes the combinatorial background of single D^(0) meson yields,fails to reproduce the correlated background in the D^(0)-D^(0) correlation measurement,while the SB background method yields a good description of the background for both single D^(0) yields and the correlated background of the D^(0)-D^(0) correlation *** further examined the validity of the correlation methods under different signal-to-background ratios,providing direct references for experimental measurements.

关键词： Heavy flavor Azimuthal correlation PYTHIA

Soil water response to precipitation in different microtopographies on the semi-arid Loess Plateau,China

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Journal of Forestry Research 2020年第1期31卷 245-256页

作者： huan ma Qingke Zhu Weijun Zhao Forestry Ecological Engineering Research Center School of Soil and Water ConservationBeijing Forestry UniversityBeijing 100083People’s Republic of China Key Laboratory of Tourism and Resources Environment in Colleges and Universities of Shandong Province Taishan UniversityTaianShandong 271000People’s Republic of China

Soil water is an important factor restricting afforestation on the semi-arid Loess *** microtopography of the loess slope has changed the distribution pattern of soil water on the *** improve water utilization efficiency and optimize afforestation configuration patterns,the relationship between soil water and precipitation at micro-topographic scale must be *** used time series analysis to study the temporal variation of soil water and its response to precipitation in four kinds of micro-topographies and undisturbed slope on loess ***-topographies significantly influenced soil water distribution and dynamics on the *** water stored in the platform,sinkhole,and ephemeral gully influenced subsequent soil water for 4 weeks,whereas soil water stored in the scarp and undisturbed slope could influence soil water for 2 *** took 12 weeks,10 weeks,18 weeks,6 weeks,and 12 weeks for precipitation to reach the deeper soil layer in the platform,sinkhole,scarp,ephemeral gully,and undisturbed slope,*** soil water characteristics in different micro-topographies are vital factors that should be taken into consideration when undertaking afforestation on the Loess Plateau.

关键词： Semi-arid Loess Plateau Micro-topography Afforestation Time series analysis Soil water