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Design and grindability assessment with cup shaped electroplated CBN wheel grinding turbine disc slots of powder metallurgy superalloy FGH96

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Chinese Journal of Aeronautics 2024年第9期37卷 521-534页

作者： Benkai LI Wenfeng DING YeJun ZHU Changhe LI Yanbin ZHANG Min YANG Xiao ma mingzheng LIU Xin CUI School of Mechanical Engineering Qingdao University of TechnologyQingdao 266520China National Key Laboratory of Science and Technology on Helicopter Transmission Nanjing University of Aeronautics and AstronauticsNanjing 210016China College of Engineering Nanjing Agricultural UniversityNanjing 210031China

The machining surface integrity of aero-engine turbine disc slots has a significant impact on their fatigue life and service performance,and achieving efficiency and high-precision machining is still a great *** high machining requirements of future aeroengine turbine disc slots will be difficult to satisfy using the broaching *** addition,existing methods of slot machin-ing face difficulties in ensuring surface *** study explored a cup shaped electroplated Cubic Boron Nitride(CBN)abrasive wheel for profile grinding the turbine disc slots of FGH96 powder metallurgy *** matrix structure of the cup shaped abrasive wheel was designed and verified.A profile grinding experiment was conducted for fir-tree slots on a five-axis machining *** accuracy and the surface integrity were *** show that the key dimension detection results of the slots were within the allowable tolerance ***,an average sur-face roughness Ra of 0.55μm was achieved,the residual stress was compressive,the plastic defor-mation layer thickness was less than 5μm,and the hardening layer thickness was less than 20μ*** research findings provide a new approach to machining the slots of aviation engine turbine discs and guidance for the high-quality processing of complex components.

关键词： Profile grinding Surface integrity Cup shaped CBN abrasive wheel Turbine disc slots FGH96

Force model in electrostatic atomization minimum quantity lubrication milling GH4169 and performance evaluation

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Frontiers of Mechanical Engineering 2024年第4期19卷 55-72页

作者： Min YANG Hao ma Zhonghao LI Jiachao HAO mingzheng LIU Xin CUI Yanbin ZHANG Zongming ZHOU Yunze LONG Changhe LI School of Mechanical and Automotive Engineering Qingdao University of TechnologyQingdao 266520China College of Physics QingdaoUniversityQingdao 266071China Hanergy Lubrication Technology Co. Ltd.Qingdao 266200China

The nickel-based high-temperature alloy GH4169 is the material of choice for manufacturing critical components in aeroengines,and electrostatic atomization minimum quantity lubrication(EMQL)milling represents a fundamental machining process for ***,the effects of electric field parameters,jet parameters,nozzle position,and milling parameters on milling performance remain unclear,which constrains the broad application of EMQL in aerospace *** study evaluated the milling performance of EMQL on nickel-based alloys using soybean oil as the lubrication *** revealed that compared with conventional pneumatic atomization MQL milling,EMQL reduced the milling force by 15.2%-15.9%,lowered the surface roughness by 30.9%-54.2%,decreased the average roughness spacing by 47.4%-58.3%,and decreased the coefficient of friction and the specific energy of cutting by 55%and 19.6%,*** optimization experiments using orthogonal arrays demonstrated that air pressure most significantly affected the milling force and specific energy of cutting,with a contribution rate of 22%,whereas voltage had the greatest effect on workpiece surface roughness,contributing 36.71%.Considering the workpiece surface morphology and the potential impact of droplet drift on environmental and health safety,the optimal parameter combination identified were a flow rate of 80 mL/h,an air pressure of 0.1 MPa,a voltage of 30 kV,a nozzle incidence angle of 35°,an elevation angle of 30°,and a target distance of 40 *** research aimed to provide technical insights for improving the surface integrity of aerospace materials that are difficult to machine during cutting operations.

关键词： electrostatic atomization MQL nickel-based alloys milling force surface roughness force model

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京广线黄河大桥桥墩浅基防护技术

铁道建筑 2005年第6期45卷 48-49页

作者：马明正西南交通大学成都610031

分析京广线黄河大桥桥基防护中片石笼流失的原因,并介绍四面六边透水框架群桥墩防护技术的防护机理、防护位置设计,并与片石笼防护法进行了比较,实际使用中,四面六边体防护效果良好。

关键词：大桥桥墩浅基防护四面六边透水框架

郑州黄河公铁两用桥钢梁架设方案的层次分析法研究

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铁道标准设计 2010年第9期30卷 3-6页

作者：马明正京广铁路客运专线河南有限责任公司郑州450003

从4个层次上构建了方案比选评价的AHP模型。根据在黄河上架设钢梁来修建特大桥进行施工的方案特点,确定了方案评价指标,即把投资、工期、技术和施工条件、环保等五个准则作为评价一个施工方案优劣的五个方面的指标;最后把指标层向下展开... 详细信息

从4个层次上构建了方案比选评价的AHP模型。根据在黄河上架设钢梁来修建特大桥进行施工的方案特点,确定了方案评价指标,即把投资、工期、技术和施工条件、环保等五个准则作为评价一个施工方案优劣的五个方面的指标;最后把指标层向下展开,形成准则层,建立了层次结构模型。本文阐述的方法和研究的结论为郑州黄河公铁两用桥钢梁架设施工提供了科学的决策依据,从方法论的角度上讲具有可推广性。可在一定条件下为其他客运专线工程特大型钢梁桥的架梁方案比选提供决策方法上的借鉴。

关键词：石武客运专线郑州黄河公铁两用桥钢梁架设方案层次分析法

Elasticity meets topology

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National Science Review 2024年第6期11卷 84-85页

作者： Guancong ma Department of Physics Hong Kong Baptist University

We are surrounded by environments and items that are made from solid materials in our daily life. Any physical contact with any items is a mechanical disturbance that produces mechanical *** underlines the crucial role that such vibrations play in our daily interactions,highlighting the need for a deeper understanding and improved manipulation of these fundamental phenomena.

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Uniform decomposition of velocity gradient tensor

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Journal of Hydrodynamics 2024年第1期36卷 24-34页

作者： Chenxi ma Chaoqun Liu Department of mathematics University of Texas at ArlingtonArlingtonTXUSA

In this paper,the principal decomposition of the velocity gradient tensor[∇v]is discussed in 3 cases based on the discriminant∆:∆0 with 3 distinct real eigen values,and∆=0 with 1 or 2 distinct real eigen *** velocity gradient tensor can also be classified as rotation point,which can be decomposed into three parts,i.e.,rotation[R],shear[S]and stretching/compression[SC],and non-rotation point,we defined a new resistance term[L],and the tensor can be decomposed into three parts,i.e.,resistance[L],shear[S]and stretching/compression[SC].Example matric are also displayed to demonstrate the new *** of principal decomposition between 3 different cases,and between Resistance and Liutex will also be discussed.

关键词： Velocity gradient Liutex resistance fluid kinematics

VOC emitted by biopharmaceutical industries:Source profiles,health risks,and secondary pollution

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Journal of Environmental Sciences 2024年第1期135卷 570-584页

作者： Jiawei ma Lin Li State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China National Engineering Laboratory for VOCs Pollution Control material&Technology University of Chinese Academy of SciencesBeijing 101408China

The biopharmaceutical industry contributes substantially to volatile organic compounds(VOCs)emissions,causing growing concerns and social developmental *** study conducted an on-site investigation of the process-based emission of VOCs from three biopharmaceutical *** the workshops of the three enterprises,26 VOCs were detected,which could be sorted into 4 classes:hydrocarbons,aromatic hydrocarbons,oxygen-containing compounds,and nitrogen-containing *** were the main components of waste gases,accounting for 44.13%-77.85%of the overall ***-based source profiles were compiled for each process unit,with the fermentation and extraction units of tiamulin fumarate being the main source of VOC *** heptanone,vinyl acetate,diethylamine,propylene glycol methyl ether(PGME),and benzene were screened as priority pollutants through a fuzzy comprehensive evaluation *** level concentration simulation results of the Gauss plume diffusion model demonstrated that the diffusivity of VOCs in the atmosphere was relatively high,indicating potential non-carcinogenic and carcinogenic risks 1.5-2 km ***,the process-based formation potentials of ozone and secondary organic aerosols(SOAs)were determined and indicated that N-methyl-2-pyrrolidone,dimethyl heptanone,and PGME should be preferentially controlled to reduce the ozone formation potential,whereas the control of benzene and chlorobenzene should be prioritized to reduce the generation of *** results provide a basis for understanding the characteristics of VOC emission by biopharmaceutical industries and their diffusion,potentially allowing the development of measures to reduce health risks and secondary pollution.

关键词： Biopharmaceutical Volatile organic compound Priority pollutant Exposure risk Secondary pollution

Deterministic and Robust Volt-var Control Methods of Power System Based on Convex Deep Learning

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Journal of Modern Power Systems and Clean Energy 2024年第3期12卷 719-729页

作者： Qing ma Changhong Deng the School of Electrical Engineering and Automation Wuhan UniversityWuhanChina

Volt-var control(VVC)is essentially a non-convex optimization problem due to the non-convexity of power flow(PF)constraints,resulting in the difficulty in obtaining the optimum without convexity *** existing second-order cone method for the convexity conversion often leads to a sharp increase in PF constraints and optimization variables,which in turn increases the optimization difficulty or even leads to optimization *** paper first proposes a deterministic VVC method based on convex deep learning power flow(DLPF).This method uses the input convex neural network(ICNN)to establish a single convex mapping between state parameters and node voltage to complete the convexity conversion while the optimization variables only correspond to reactive power equipment,which can ensure the global optimum with extremely fast computation *** cope with the impact brought by the uncertainty of distributed energy and omit the additional worst scenario search of traditional robust VVC,this paper proposes robust VVC method based on convex deep learning interval power flow(DLIPF),which continues to adopt ICNN to establish another convex mapping between state parameters and node voltage *** DLIPF with DLPF,this method decreases the modeling and optimization difficulty of robust VVC *** results on 30-bus,118-bus,and 200-bus systems prove the correctness and rapidity of the proposed methods.

关键词： Volt-var control convexity conversion convex deep learning power flow

Copper slag assisted coke reduction of phosphogypsum for sulphur dioxide preparation

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Chinese Journal of Chemical Engineering 2024年第1期65卷 43-53页

作者： Dong ma Qinhui Wang State Key Laboratory of Clean Energy Utilization Institute for Thermal Power EngineeringZhejiang UniversityHangzhou 310027China

The reduction of phosphogypsum(PG)to lime slag and SO_(2)using coke can effectively alleviate the environmental problems caused by ***,the PG decomposition temperature remains high and the product yield remains *** adding additives,the decomposition temperature can be further reduced and PG decomposition rate and product yield can be ***,the use of current additives such as Fe_(2)O_(3)and SiO_(2)brings the problem of increasing economic ***,it is proposed to use solid waste copper slag(CS)as a new additive to reduce PG to prepare SO2,which can reduce the cost and meet the environmental benefits at the same *** effects of proportion,temperature and thermostatic time on PG decomposition are investigated by experimental and kinetic analysis combined with FactSage thermodynamic calculations to optimize the roasting ***,the reaction mechanism is *** is found that adding CS to the coke and PG system can increase the rate of PG decomposition and SO_(2)yield while lowering the PG decomposition *** example,when the CS/PG mass ratio increases from 0 to 1,PG decomposition rate increases from 83.38%to 99.35%,SO_(2)yield increases from 78.62%to 96.81%,and PG decomposition temperature decreases from 992.4℃to 949.6℃.The optimal reaction parameters are CS/PG mass ratio of 1,Coke/PG mass ratio of 0.06 at 1100℃for 20 min with 99.35%PG decomposition rate and 96.81%SO_(2) *** process proceeds according to the following reactions:2CaSO_(4)+ 0.7C + 0.8Fe_(2)SiO_(4)→0.8Ca_(2)SiO_(4)+ 0.2Ca_(2)Fe_(2)O_(5)+ 0.4Fe_(3)O_(4)+2SO_(2)+ 0.7CO_(2)Finally,a process for decomposing PG with coke and CS is proposed.

关键词： Phosphogypsum Sulfur dioxide Copper slag Fluidized-bed Reduction Waste treatment