检索结果-南通市图书馆

Theoretical Modeling and Surface Roughness Prediction of Microtextured Surfaces in Ultrasonic Vibration-Assisted Milling

引用

Chinese Journal of mechanical engineering 2024年第2期37卷 163-183页

作者： Chenbing Ni Junjie Zhu Youqiang Wang Dejian Liu Xuezhao Wang Lida Zhu school of mechanical and automotive engineering Qingdao University of TechnologyQingdao 266525China school of mechanical engineering and Automation Northeastern UniversityShenyang 110819China

Textured surfaces with certain micro/nano structures have been proven to possess some advanced functions,such as reducing friction,improving wear and increasing *** prediction of micro/nano surface textures is of great significance for the design,fabrication and application of functional textured *** this paper,based on the kinematic analysis of cutter teeth,the discretization of ultrasonic machining process,transformation method of coordinate systems and the cubic spline data interpolation,an integrated theoretical model was established to characterize the distribution and geometric features of micro textures on the surfaces machined by different types of ultrasonic vibration-assisted milling(UVAM).Based on the theoretical model,the effect of key process parameters(vibration directions,vibration dimensions,cutting parameters and vibration parameters)on tool trajectories and microtextured surface morphology in UVAM is ***,the effect of phase difference on the elliptical shape in 2D/3D ultrasonic elliptical vibration-assisted milling(UEVAM)was *** to conventional numerical models,the method of the cubic spline data interpolation is applied to the simulation of microtextured surface morphology in UVAM,which is more suitable for characterizing the morphological features of microtextured surfaces than traditional methods due to the presence of numerous micro *** prediction of surface roughness indicates that the magnitude of ultrasonic amplitude in z-direction should be strictly limited in 1D rotary UVAM,2D and 3D UEVAM due to the unfavorable effect of axial ultrasonic vibration on the surface *** study can provide theoretical guidance for the design and fabrication of microtextured surfaces in UVAM.

关键词： Theoretical modeling Microtextured surface Ultrasonic vibration-assisted milling Cubic spline interpolation Surface roughness

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Theoretical study on the effect of H_(2)O on the formation mechanism of NO_(x) precursors during indole pyrolysis

引用

Frontiers of Chemical Science and engineering 2024年第6期18卷 99-112页

作者： Ziqi Wang Jun Shen Xuesong Liu Sha Wang Shengxiang Deng Hai Zhang Yun Guo school of mechanical and automotive engineering Shanghai University of Engineering ScienceShanghai 201620China school of mechanical engineering Shanghai Jiao Tong UniversityShanghai 200240China

The incineration technology of kitchen waste is one of the effective technologies to achieve the resource utilization of municipal solid *** is an important stage of *** is a rich initial product in the pyrolysis process of kitchen waste,and the presence of H_(2)O has a significant impact on the decomposition of indole to form NO_(x) ***,this study uses density functional theory method to study the effect of H_(2)O on the thermal decomposition of indole to produce NH_(3),HNCO,and *** H_(2)O participates in the reaction,it can provide oxidative groups to generate a new product HNCO,which is different from the previous findings by indole pyrolysis without the presence of H_(2)***,this study theoretically proves that NH_(3) is easier to form than *** is consistent with the phenomenon that NH_(3) release is higher than HCN release in pyrolysis *** addition,compared with the individual pyrolysis of indole,the participation of H_(2)O reduces the energy barriers for the formation of NH_(3) and HCN during indole pyrolysis,thereby promoting the formation of NH_(3) and HCN.

关键词： indole pyrolysis H_(2)O NO_(x)precursors DFT

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

A Deep Learning-Enabled Skin-Inspired Pressure Sensor for Complicated Recognition Tasks with Ultralong Life

引用

Research 2024年第1期2023卷 443-454页

作者： Yingxi Xie Xiaohua Wu Xiangbao Huang Qinghua Liang Shiping Deng Zeji Wu Yunpeng Yao Longsheng Lu school of mechanical&automotive engineering South China University of TechnologyGuangzhouChina

Flexible full-textile pressure sensor is able to integrate with clothing directly,which has drawn extensive attention from scholars *** the realization of flexible full-textile pressure sensor with high sensitivity,wide detection range,and long working life remains *** recognition tasks necessitate intricate sensor arrays that require extensive data processing and are susceptible to *** human skin is capable of interpreting tactile signals,such as sliding,by encoding pressure changes and performing complex perceptual *** by the skin,we have developed a simple dip-and-dry approach to fabricate a full-textile pressure sensor with signal transmission layers,protective layers,and sensing *** sensor achieves high sensitivity(2.16 kPa^(−1)),ultrawide detection range(0 to 155.485 kPa),impressive mechanical stability of 1 million loading/unloading cycles without fatigue,and low material *** signal transmission layers that collect local signals enable real-world complicated task recognition through one single *** developed an artificial Internet of Things system utilizing a single sensor,which successfully achieved high accuracy in 4 tasks,including handwriting digit recognition and human activity *** results demonstrate that skin-inspired full-textile sensor paves a promising route toward the development of electronic textiles with important potential in real-world applications,including human–machine interaction and human activity detection.

关键词： Deep Skin utilizing

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

A Coordinate-Free Approach to the Design of Generalized Griffis-Duffy Platforms

引用

Chinese Journal of mechanical engineering 2024年第3期37卷 95-103页

作者： Chengwei Shen Xu Pei Lubin Hang Jingjun Yu College of Optical Mechanical and Electrical EngineeringZhejiang A&F UniversityHangzhou 311300China school of mechanical engineering and Automation Beihang UniversityBeijing 100191China school of mechanical and automotive engineering Shanghai University of Engineering ScienceShanghai 201620China

Architectural singularity belongs to the Type II singularity,in which a parallel manipulator(PM)gains one or more degrees of freedom and becomes *** remaining permanently in a singularity are beneficial for linearto-rotary motion ***-Duffy(GD)platform is a mobile structure admitting a Bricard *** this paper,we present a coordinate-free approach to the design of generalized GD platforms,which consists in determining the shape and attachment of both the moving platform and the fixed *** generalized GD platform is treated as a combination of six coaxial single-loop mechanisms under the same *** to the inversion,hidden in the geometric structure of these single-loop mechanisms,the mapping from a line to a circle establishes the geometric transformation between the fixed base and the moving platform based on the center of inversion,and describes the shape and attachment of the generalized GD ***,the center of inversion not only identifies the location of rotation axis,but also affects the shape of the platform mechanism.A graphical construction of generalized GD platforms using inversion,proposed in the paper,provides geometrically feasible solutions of the manipulator design for the requirement of the location of rotation axis.

关键词： Generalized Griffis-Duffy platforms Self-motion Inversion Coordinate-free determination Manipulator design

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Simulation Study of Diesel Spray Tilt Angle and Ammonia Energy Ratio Effect on Ammonia-Diesel Dual-Fuel Engine Performance

引用

Energy engineering 2024年第9期121卷 2603-2620页

作者： Zhifeng Zhao Xuelong Miao Xu Chen Jinbao Zheng Yage Di Zhenjie Bao Zhuo Yang mechanical and automotive engineering school Shanghai University of Engineering ScienceShanghai201620China

Ammonia-diesel dual fuel(ADDF)engines for transportation applications are an important way to reduce carbon *** order to achieve better combustion of ammonia in diesel engines.A small-bore single-cylinder engine was converted into an ADDF engine with the help of mature computational fluid dynamics(CFD)simulation software to investigate the performance of an engine with a high ammonia energy ratio(AER),and to study the effect of spray tilt angle on ADDF *** results showed that the increase in AER reduced nitric oxide(NO)and nitrogen dioxide(NO2)emissions but increased nitrous oxide(N2O)and unburned ammonia *** in the range of 50%-70%achieved lower greenhouse gases(GHG)emissions than the pure diesel *** to the pure diesel mode,when the AER was 60%,the indicated thermal efficiency(ITE)was increased by 0.2%and the GHG emissions were decreased by 22.3%,but carbon monoxide(CO)and Hydrocarbon(HC)emissions were *** the in-cylinder combustion temperature or high-temperature region range of the ADDF engine could reduce GHG *** an AER of 60%,an increase in the spray tilt angle helped the ammonia combustion in the residual gap to reduce the unburned ammonia *** to the pure diesel mode with a spray tilt angle of 75°,an AER of 60%with a spray tilt angle of 77.5°improved the ITE by 1.5%,and reduced theGHGemissions by 25.7%.Adjusting the spray tilt angle of theADDFengine also *** is an effective way to improve ADDF engine performance by adjusting the spray tilt angle.

关键词： Ammonia-diesel engine ammonia energy ratio greenhouse gases carbon-free fuel

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

In-situ additive manufacturing of high strength yet ductility titanium composites with gradient layered structure using N_(2)

引用

International Journal of Extreme Manufacturing 2024年第3期6卷 387-409页

作者： Yunmian Xiao Changhui Song Zibin Liu Linqing Liu Hanxiang Zhou Di Wang Yongqiang Yang school of mechanical and automotive engineering South China University of TechnologyGuangzhou 510641People’s Republic of China

It has always been challenging work to reconcile the contradiction between the strength and plasticity of titanium *** powder bed fusion(LPBF) is a convenient method to fabricate innovative composites including those inspired by gradient layered *** this work,we used LPBF to selectively prepare Ti N/Ti gradient layered structure(GLSTi)composites by using different N_(2)–Ar ratios during the LPBF *** systematically investigated the mechanisms of in-situ synthesis Ti N,high strength and ductility of GLSTi composites using microscopic analysis,TEM characterization,and tensile testing with digital image ***,a digital correspondence was established between the N_(2) concentration and the volume fraction of LPBF in-situ synthesized Ti *** results show that the GLSTi composites exhibit superior mechanical properties compared to pure titanium fabricated by LPBF under pure ***,the tensile strength of GLSTi was more than 1.5times higher than that of LPBF-formed pure titanium,reaching up to 1100 MPa,while maintaining a high elongation at fracture of 17%.GLSTi breaks the bottleneck of high strength but low ductility exhibited by conventional nanoceramic particle-strengthened titanium matrix composites,and the hetero-deformation induced strengthening effect formed by the Ti N/Ti layered structure explained its strength-plasticity balanced *** microhardness exhibits a jagged variation of the relatively low hardness of 245 HV0.2 for the pure titanium layer and a high hardness of 408 HV0.2 for the N_(2) in-situ synthesis *** study provides a new concept for the structure-performance digital customization of 3D-printed Ti-based composites.

关键词： laser powder bed fusion layered structure composites in-situ synthesis TiN strength-plasticity synergy

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A Study of the Effect of the Miller Cycle on the Combustion of a Supercharged Marine Diesel Engine

引用

Energy engineering 2024年第5期121卷 1363-1380页

作者： Lingjie Zhao Cong Li mechanical and automotive engineering school Shanghai University of Engineering ScienceShanghai201600China

The Miller cycle is a program that effectively reduces NOx emissions from marine diesel engines by lowering the maximum combustion temperature in the cylinder,thereby reducing NOx *** effectively investigate the impact of Miller cycle optimum combustion performance and emission capability under high load conditions,this study will perform a one-dimensional simulation of the performance of a marine diesel engine,as well as a threedimensional simulation of the combustion in the cylinder.A 6-cylinder four-stroke single-stage supercharged diesel engine is taken as the research *** chassis dynamometer and other related equipment are used to build the test system,carry out the diesel engine bench test,and collect experimental *** simulation results are compared with the test results,and the error is less than 5%.In this study,the authors will use simulation software to simulate several Miller cycle scenarios designed for early inlet valve closure and analyze the impact of the Miller cycle on combustion and emissions at 100%load *** comparing the flow field distribution of the engine at 1500 r/min condition,it was found that proper EIVC can prolong the ignition latency period and homogeneous fuel-air mixture combustion acceleration,but it can reduce pressure and temperature within the piston chamber and NOx ***,the Miller cycle reduces end-of-compression temperatures,which increases combustion duration and exhaust temperatures,making it difficult to improve fuel economy at the optimum fuel consumption point,and closing the intake valves prematurely leads to excessive fuel ***,temperature and heat release rate within the piston chamber,NOx,and SOOT generation were significantly enhanced.

关键词： Miller cycle EIVC combustion NOx emissions marine diesel

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Investigation of wake-induced vibration interference between two staggered wave-cone cylinders at subcritical Reynolds number

引用

Journal of Hydrodynamics 2024年第2期36卷 378-393页

作者： Lin Zou Di-wei Liu Jian Liu Hong-cheng Zuo Yin-huan Zheng Hao Xia school of mechanical and Electronic engineering Wuhan University of TechnologyWuhan430070China Department of Aeronautical and automotive engineering Loughborough UniversityLoughboroughUK

The wake induced vibration(WIV)of a one-and two-degree-of-freedom(1DOF,2DOF)downstream wave-cone cylinder(WCC)behind a stationary equal-size upstream wave-cone cylinder in the staggered arrangement is numerically investigated at subcritical Reynolds number of 3900 by using shear stressed transfer(SST)k-ωturbulence *** streamwise pitch ratios(P/Dm)vary from 4 to 6 with a fixed incident angleα=8°.Experimental measurements were also performed for the validation of the present numerical *** is found that the largest vibration amplitude in crossflow direction occurred at P/Dm=4,Ur=8 with small difference of streamwise vibration at P/Dm=4,*** from single wavy-cone cylinder(SWCC),the downstream flexible one of a pair staggered WCCs got larger vibration amplitude during phase switching stage instead of in-phase *** upstream wake will suppress the triple frequency of main frequency in the power spectra density(PSD)functions of Cl but stimulate the double one of *** intriguing vibration mechanism happened in all 2DOF cases where the trajectory of downstream WCC is a significant ellipse rather than a figure of *** transformation of phase switching and the variation of the main frequency of drag coefficient(Cd)can be explained by the vortex-shedding modes of downstream WCC.

关键词： Two wave-cone cylinders staggered arrangement wake induced vibration phase switching vortex shedding

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

ST-LaneNet: Lane Line Detection Method Based on Swin Transformer and LaneNet

引用

Chinese Journal of mechanical engineering 2024年第1期37卷 130-145页

作者： Yufeng Du Rongyun Zhang Peicheng Shi Linfeng Zhao Bin Zhang Yaming Liu school of mechanical engineering Anhui Polytechnic UniversityWuhu 241000China automotive New Technology Anhui engineering and Technology Research Center Anhui Polytechnic UniversityWuhu 241000China school of automotive and Transportation engineering Hefei University of TechnologyHefei 230009China

The advancement of autonomous driving heavily relies on the ability to accurate lane lines *** deep learning and computer vision technologies evolve,a variety of deep learning-based methods for lane line detection have been proposed by researchers in the ***,owing to the simple appearance of lane lines and the lack of distinctive features,it is easy for other objects with similar local appearances to interfere with the process of detecting lane *** precision of lane line detection is limited by the unpredictable quantity and diversity of lane *** address the aforementioned challenges,we propose a novel deep learning approach for lane line *** method leverages the Swin Transformer in conjunction with LaneNet(called ST-LaneNet).The experience results showed that the true positive detection rate can reach 97.53%for easy lanes and 96.83%for difficult lanes(such as scenes with severe occlusion and extreme lighting conditions),which can better accomplish the objective of detecting lane *** 1000 detection samples,the average detection accuracy can reach 97.83%,the average inference time per image can reach 17.8 ms,and the average number of frames per second can reach 64.8 *** programming scripts and associated models for this project can be accessed openly at the following GitHub repository:https://***/Duane 711/Lane-line-detec tion-ST-LaneNet.

关键词： Autonomous driving Lane line detection Deep learning Swin transformer

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

On the electric behaviour of conductive grease inside the contact zone

引用

Friction 2024年第4期12卷 683-697页

作者： Yuxin ZHOU Jinjie LIU Xinming LI He CHONG Bo HAN Qinghua BAI SKF(Shanghai)automotive Technologies Co. Ltd.Shanghai 201814China school of mechanical and automotive engineering Qingdao University of TechnologyQingdao 266250China

Conductive grease has been considered as a potential solution in addressing electric erosion issue inside motor *** the conductive grease performance,especially the electric and tribological behaviour is crucial for its *** paper combines bulk grease characterization and contact film study considering both electrical and tribological loading *** results show that the electric performance for the selected conductive grease sample is electric field dependent,including both frequency and voltage *** film impedance inside the contact area is closely related to the external electric field,running condition,and lubrication *** following film impedance calculation tells that not only bulk grease electric parameters,but the contact parameter,lubricant film contour and lubrication condition should be considered when performing the overall bearing electrical modelling.

关键词： Electric erosion lubricant conductivity grease film impedance

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：