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Properties and strengthening mechanism of brush plated nanoparticle reinforced composite coatings

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中国有色金属学会会刊：英文版 2004年第z1期14卷 182-185页

作者： dong shi-yun XU Bin-shi MA shi-ning TU Wei-yi National Key Laboratory for Remanufacturing Academy of Armored Force Engineering Beijing 100072 China National Key Laboratory for RemanufacturingAcademy of Armored Force Engineering Beijing 100072 China National Key Laboratory for RemanufacturingAcademy of Armored Force Engineering Beijing 100072 China National Key Laboratory for RemanufacturingAcademy of Armored Force Engineering Beijing 100072 China

Nanoparticle reinforced nickel matrix composite coatings, such as n-Al2O3/Ni, n-SiO2/Ni, n-SiC/Ni and n-TiO2/Ni, were fabricated by brush plating technique. Hardness, wear resistance and contact-fatigue resistance of the composite coatings were determined, and strengthening mechanism of the composite coatings was discussed. Results show that the composite coatings have superior properties to the Ni metal coating. Compared with properties of brush plated Ni metal coating, the composite coatings have hardness over 1.5 times and wear resistance capability of about 2.5 times. The strengthening mechanism of the composite coatings mainly includes fine-crystal grain effect, nanoparticle dispersion effect and dislocation effect.

关键词： nanoparticles brush plated coatings strengthening mechanism

Micro mechanical properties of n-Al2O3/Ni composite coating by nanoindentation

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中国有色金属学会会刊：英文版 2004年第z1期14卷 115-119页

作者： WANG Hong-mei XU Bin-shi MA shi-ning dong shi-yun LI Xiao-ying National Key Laboratory for Remanufacturing Academy of Armored Force Engineering Beijing 100072 China National Key Laboratory for RemanufacturingAcademy of Armored Force Engineering Beijing 100072 China National Key Laboratory for RemanufacturingAcademy of Armored Force Engineering Beijing 100072 China National Key Laboratory for RemanufacturingAcademy of Armored Force Engineering Beijing 100072 China School of Metallurgy and Materials The University of Birmingham Birmingham B152TT UK

A new type of nano test system was introduced, the test principle and the indentation data analysis method were described. It was used to test the micro mechanical properties, such as hardness, elastic modulus and indentation creep property of n-Al2O3/Ni composite coating on steel prepared by brush plating, and the variety of mechanical properties with coating thickness was researched. The results show that the mechanical properties are basically identical within the whole coating, the hardness and modulus decrease in the defect fields, especially within the dendritic crystals, whereas the mechanical properties are not influenced greatly at the interspaces among dendritic crystals. The average hardness and elastic modulus of n-Al2O3/Ni coating are 6.34 GPa and 154 GPa respectively, and the hardness is 2.4 times higher than that of steel and the indentation creep curve of n-Al2O3/Ni coating is similar to that of the uniaxial compression creep, and the creep rate of steady-state is about 0. 104 nm/s. These results will supply useful data for process improvement, new type material development and application expansion.

关键词： nanoindentation hardness elastic modulus creep property nano composite coating

Influence of heat treatment on microstructures and micro-hardness of n-SiO2/Ni composite coating

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中国有色金属学会会刊:英文版 2004年第z1期14卷 111-114页

作者： XU Bin-shi WANG Hai-dou dong shi-yun JIANG Bin TU Wei-yi National Key Laboratory for remanufacturing Academy of Armored Force Engineering Beijing 100072 China

The n-SiO2/Ni composite electro-brush plating coating was prepared on the 1045 steel substrate. SEM and TEM were utilized to analyze the surface and cross-section morphologies or the microstructures of the composite coating before and after heat treatment, as well as a micro-hardness tester was used to measure the micro-hardness before and after heat treatment. The results show that the entrance of nano SiO2 particles into composite coating makes the micro-hardness higher. After heat treatment, due to the obstruction to growth of Ni crystals from nano particles, the composite coating still possesses a higher micro-hardness than that of common Ni-base coating.

关键词： nano SiO2 particles electro-brush plating composite coating heat treatment microstructures microhardness

Wear behavior of high velocity arc sprayed 3Cr13 steel coating in oil containing sand

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中国有色金属学会会刊：英文版 2004年第z1期14卷 370-373页

作者： DU Ling-zhong XU Bin-shi dong shi-yun YANG Hua WU Yi-xiong College of Materials Science and Engineering Shanghai Jiaotong UniversityShanghai 200030 China National Key Laboratory for Remanufacturing Academy of Armored Force Engineering Beijing 100072 China National Key Laboratory for Remanufacturing Academy of Armored Force Engineering Beijing 100072 China National Key Laboratory for Remanufacturing Academy of Armored Force Engineering Beijing 100072 China National Key Laboratory for Remanufacturing Academy of Armored Force Engineering Beijing 100072 China College of Materials Science and Engineering Shanghai Jiaotong UniversityShanghai 200030 China

To improve the wear resistance of the machine components serving in desert areas, the 3Cr13 stainless steel coating was produced by the high velocity arc spraying technique. The microstructure and phase constitute of the coating were analyzed by SEM and XRD. The effects of sand content on the friction and wear behaviors of the coating under the lubrication of oil containing sand were investigated on a ball-on-disk tester. SEM was used to reveal the wear mechanisms of the coating. The results show that the wear volume increases with increasing the sand content in the oil, and the sprayed coating exhibits better triobological properties compared with the 1045 steel. The predominant wear mechanisms of the sprayed coating are micro-cutting, brittle fracture and delamination.

关键词： high velocity arc spraying coating friction and wear behavior oil sand

Fatigue damage evaluation by metal magnetic memory testing

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Journal of Central South University 2014年第1期21卷 65-70页

作者：王慧鹏董丽虹董世运徐滨士 National Key Laboratory for Remanufacturing Academy of Armored Forces Engineering

Tension-compression fatigue test was performed on 0.45% C steel *** and tangential components of magnetic memory testing signals,Hp(y) and Hp(x) signals,with their characteristics,K of Hp(y) and Hp(x)M of Hp(x),throughout the fatigue process were presented and *** peaks of Hp(y) and peak of Hp(x) reversed after loading; Hp(y) curves rotated clockwise and Hp(x) curves elevated significantly with the increase of fatigue cycle number at the first a few fatigue cycles,both Hp(y) and Hp(x) curves were stable after that,the amplitude of abnormal peaks of Hp(y) and peak value of Hp(x) increased more quickly after fatigue crack *** peaks of Hp(y) and peak of Hp(x) at the notch reversed again after *** characteristics were found to exhibit consistent tendency in the whole fatigue life and behave differently in different stages of *** initial and crack developing stages,the characteristics increased significantly due to dislocations increase and crack propagation,*** stable stage,the characteristics remained constant as a result of dislocation blocking,K value ranged from 20 to 30 A/(m·mm)-1,and Hp(x)M ranged from 270 to 300 A/m under the test parameters in this *** failure,both abnormal peaks of Hp(y) and peak of Hp(x) reversed,K value was 133 A/(m·mm)-1 and Hp(x)M was-640 A/*** results indicate that the characteristics of Hp(y) and Hp(x) signals were related to the accumulation of fatigue,so it is feasible and applicable to monitor fatigue damage of ferromagnetic components using metal magnetic memory testing(MMMT).

关键词： metal magnetic memory testing MMMT signal tension-compression fatigue test feature extraction

Identification of reservoir types in deep carbonates based on mixedkernel machine learning using geophysical logging data

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Petroleum Science 2024年第3期21卷 1632-1648页

作者： Jin-Xiong shi Xiang-Yuan Zhao Lian-Bo Zeng yun-Zhao Zhang Zheng-Ping Zhu Shao-Qun dong Key Laboratory of Exploration Technologies for Oil and Gas Resources of the Ministry of Education Yangtze UniversityWuhan4310HubeiChina School of Geosciences Yangtze UniversityWuhan430100HubeiChina College of Geosciences China University of Petroleum(Beijing)Beijing102249China Petroleum Exploration and Production Research Institute of SINOPEC Beijing100083China School of Earth Sciences and Engineering Xi'an Shiyou UniversityXi'an 710065ShaanxiChina

Identification of reservoir types in deep carbonates has always been a great challenge due to complex logging responses caused by the heterogeneous scale and distribution of storage *** cross-plot analysis and empirical formula methods for identifying reservoir types using geophysical logging data have high uncertainty and low efficiency,which cannot accurately reflect the nonlinear relationship between reservoir types and logging ***,the kernel Fisher discriminant analysis(KFD),a kernel-based machine learning technique,attracts attention in many fields because of its strong nonlinear processing ***,the overall performance of KFD model may be limited as a single kernel function cannot simultaneously extrapolate and interpolate well,especially for highly complex data *** address this issue,in this study,a mixed kernel Fisher discriminant analysis(MKFD)model was established and applied to identify reservoir types of the deep Sinian carbonates in central Sichuan Basin,*** MKFD model was trained and tested with 453 datasets from 7 coring wells,utilizing GR,CAL,DEN,AC,CNL and RT logs as input *** particle swarm optimization(PSO)was adopted for hyper-parameter optimization of MKFD *** evaluate the model performance,prediction results of MKFD were compared with those of basic-kernel based KFD,RF and SVM ***,the built MKFD model was applied in a blind well test,and a variable importance analysis was *** comparison and blind test results demonstrated that MKFD outperformed traditional KFD,RF and SVM in the identification of reservoir types,which provided higher accuracy and stronger *** MKFD can therefore be a reliable method for identifying reservoir types of deep carbonates.

关键词： Reservoir type identification Geophysical logging data Kernel Fisher discriminantanalysis Mixedkernel function Deep carbonates

Projections of summer light rain frequency in typical terrain over eastern China under wind speed constraint

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Science China Earth Sciences 2024年第6期67卷 1885-1894页

作者： Xuechen dong Daoyi GONG Cuicui shi Institute of Disaster Risk Science Faculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China Key Laboratory of Environmental Change and Natural Disaster MOEFaculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China School of National Safety and Emergency Management Beijing Normal UniversityBeijing 100875China School of Systems Science Beijing Normal UniversityBeijing 100875China

The variation in near-surface wind speed is a key dynamic parameter in the orographic effect of precipitation over eastern *** this study,we used the latest high-resolution outputs from six GCMs in CMIP6-HighResMIP to evaluate the performance of high-resolution models in simulating the orographic precipitation characteristics of typical mountainous areas in summer over eastern *** orographic precipitation under warming scenarios was projected and constrained according to observational *** results indicated that during the contemporary climate reference period(1979-2009),although the relationship between model-simulated near-surface wind speed and orographic light rain frequency was consistently stable,the sensitivity of the orographic light rain frequency to surface wind variability was generally underestimated,with a deviation approximately 24.1% lower than the observational *** estimated orographic light rain frequency corrected based on the observed near-surface wind speed under a 1.5℃ warming scenario,was 36.1% lower than that of the contemporary period;this reduction was 8.6 times that without the wind speed constraint(4.2%).The MRI-AGCM3-2-S model,with a longer dataset,demonstrated relatively stable reductions in orographic light rain frequency under different warming scenarios(1.5℃,2℃,3℃,and 4℃)after the application of wind speed *** all cases,the reductions exceeded those for the predictions made without the wind speed constraint.

关键词： Frequency of orographic light rain HighResMIP High-resolution projection Observational constraint Eastern China

Loss of bifurcation patency after cross-over stenting of ostial lesions in superficial femoral artery： possible causes, prevention and reintervention

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Chinese Medical Journal 2014年第18期127卷 3291-3295页

作者： Jiang Junhao Chen Bin dong Zhihui shi yun Li Weimiao Yue Jianing Department of Vascular Surgery Zhongshan Hospital FudanUniversity Shanghai 200032 China

Background Crossover stenting across the origin of the profunda femoral artery （PFA） and occasionally into the common femoral artery （CFA） is commonly used after suboptimal balloon angioplasty of ostial occlusive lesions of the superficial femoral artery （SFA） involving the bifurcation. Late stent occlusion at the bifurcation is not rare and results in severe lower extremity ischemia. Therefore, we tried to assess its possible causes, prevention and reintervention. Methods Using a prospectively maintained single-center database, 12-month femoral bifurcation patency was retrospectively compared and lesion and procedural predictors of stent occlusion were determined among 63 patients （64 lesions） who between July 2011 and February 2013 underwent crossover （36 non-jailed and 15 jailed SFA, and 12 distal and 1 complete CFA） stenting of de novo ostial SFA lesions. Results Twelve-month overall patency rate at the femoral bifurcation was 88%, with no significant difference between jailed-ostial SFA （80%） and distal CFA （67%） stenting （P=0.731）, and significant differences between either and non-jailed ostial stenting （100%,P=0.035 and 0.002）. When PFA ostium was jailed by the stent, patients with preexisting CFA or PFA lesions had a 12-month bifurcation patency rate of 20%, significantly lower than those with simple ostial SFA lesions （83%, P=0.015）. Stent induced intimal hyperplasia caused bifurcation occlusion in 6 surgical reintervention cases. Conclusions In crossover stenting of ostial lesions in SFA, bifurcation patency loss was significantly higher in distal CFA and jailed ostial SFA stenting than non-jailed ostial SFA stenting. Preexisting CFA or PFA lesion is a significant risk factor for bifurcation patency loss when PFA ostium is jailed by crossover stenting.

关键词： peripheral arterial disease endovascular therapy femoral bifurcation perioperative outcomes

Dual metal ions/BNQDs boost PMS activation over copper tungstate photocatalyst for antibiotic removal:Intermediate,toxicity assessment and mechanism

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Journal of Materials Science & Technology 2024年第3期170卷 11-24页

作者： Ruyao Chen Haiyue Zhang Yuming dong Haifeng shi School of Science Jiangnan UniversityWuxi214122China The Key Laboratory of Synthetic and Biological Colloids Ministry of EducationJiangnan UniversityWuxi214122China National Laboratory of Solid State Microstructures Nanjing UniversityNanjing210093China

In the metal-based peroxymonosulfate(PMS)activation process,the sluggish surface redox cycle of metal ions generally hampered the efficiency of PMS activation for pollutant ***,Codoped CuWO 4/BN quantum dots(CW/Co/BNQDs)photocatalysts were developed to realize Cu^(2+)/Cu+and Co^(2+)/Co^(3+)dual ions redox cycles for PMS activation,which would facilitate the tetracycline(TC)***/4Co/2BNQDs could degrade 94.8%TC within 30 min in PMS/Vis system,and the apparent rate constant of CW/4Co/2BNQDs was 2.7 times and 1.2 times higher than those of CW and CW/4Co,*** improved TC degradation performance could be attributed to the synergetic effect between BNQDs and dual redox cycles.X-ray photoelectron spectroscopy(XPS)spectra of samples before and after the reaction demonstrated that BNQDs were beneficial for accelerating the Cu^(2+)/Cu+and Co^(2+)/Co^(3+)redox cycles in CW/4Co/2BNQDs,further boosting the activation of PMS in TC *** of different radical scavengers revealed that the SO_(4)^(·−)/·OH/h+/^(1)O_(2)reactive species participated in the PMS activation for the TC degradation *** possible TC degradation pathway and intermediate toxicity were detailed *** addition,CW/4Co/2BNQDs exhibited outstanding photocatalytic activity over five consecutive cycles,which illustrated that it was supposed to be a reliable PMS activator over antibiotic elimination for practical *** this work shed new light on constructing dual redox cycles for efficient PMS activation.

关键词： Dual redox cycles Photocatalysis Peroxymonosulfate BN quantum dots Toxicity assessment