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Characteristics of life-cycle carbon dioxide emissions of arterial highway maintenance and the influencing factors

Advances in Climate Change Research 2024年第4期15卷 751-765页

作者： Yao wang yuan-qing wang Shu-Juan JI Si-Jia SUN Shu-Hong MA Ya-Nan GAO Key Laboratory of Transport Industry of Management Control and Cycle Repair Technology for Traffic Network Facilities in Ecological Security Barrier Area Chang'an UniversityXi'an 710064China Guangzhou Aids to Navigation Office Southem Navigation Service CenterMaritime Safety AdministrationGuangzhou 51000China

With the focus of highway development transitioning from construction to maintenance,a comprehensive understanding of the characteristics and influencing factors of carbon dioxide(CO_(2))emissions from highway maintenance activities is crucial for formulating effective strategies to promote the low-carbon development of road ***,the quantitative relationships between CO_(2) emissions from highway maintenance schemes and factors such as pavement deterioration,traffic volume,and road grade remain unclear owing to a lack of compre-hensive,multi-category,and real *** real maintenance data from 340 arterial highway segments in China,this study conducts the life cycle assessment(LCA)to estimate CO_(2) emissions from maintenance activities and examines the primary emission sources among various structural layers and ***,multiple linear regression(MLR)analysis is conducted to investigate the impact of traffic volume,road grade,and pavement deterioration on CO_(2) emissions from maintenance projects,and factors influencing the early-stage degradation of pavement *** results demonstrate that average CO_(2) emissions from heavy rehabilitation projects are 6.97 times higher than those from medium rehabilitation *** from heavy rehabilitation projects exhibit a significantly negative linear relationship with the riding quality index(RQI)before maintenance(p<0.05),and emissions from medium rehabilitation projects show a significant negative linear relationship with the pavement condition index(PCI)before maintenance(p<0.05).Emissions from heavy and medium rehabilitation projects are significantly positively correlated with heavy vehicle traffic volume before maintenance(p<0.05).Moreover,the early-stage degradation of PCI after heavy rehabilitation and RQI after medium rehabilitation exhibit significantly negative linear relationships with their respective in-dicators before maintenance(p<0.05).The early-stage d

关键词： Life cycle assessment(LCA) Arterial highway Maintenance Emission factor Pavement performance Traffic volume

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Effects of metallic microstructures on fatigue fracture of Q345 steel

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Journal of Iron and Steel Research International 2020年第6期27卷 702-709页

作者： Han-qing Liu Chun-ming wang Hong Zhang Zhi-yong Huang qing-yuan wang Qiang Chen School of Aeronautics and Astronautics Sichuan UniversityChengdu 610065SichuanChina Failure Mechanics and Engineering Disaster Prevention and Mitigation Key Laboratory of Sichuan Province Sichuan UniversityChengdu 610065SichuanChina Department of Mechanical Engineering Kyushu UniversityFukuoka 819-0395Japan School of Materials Science and Engineering Jiangxi University of Science and TechnologyGanzhou 341000JiangxiChina

Effects of high-frequency cyclic loading on the banded ferrite-pearlite steel were analyzed through crack initiation and propagation. Interfaces of ferrite and pearlite colony with a small angle deviation from the loading axis were verified to be the most potential sites to fabricate the microcracks caused by the high strain gradient. The initial crack extension inside ferrite grain was driven by shear stress in model II along the direction with a 45° angle to the loading axis. Banded pearlite colony and the high-angle grain boundaries were considered as the dominant factors that promote the fatigue resistance of the material through arousing crack deflection in short crack propagation range and crack branching in long crack propagation range to reduce the crack propagation driving force in the crack tip. P-S-N curves were used to quantify the dispersion of fatigue lifetimes and evaluate the effect of elevated volume content of pearlite colony on the fatigue performance of the material.

关键词： Ferrite-pearlite steel High-cycle fatigue Crack propagation Crack branching High-angle grain boundary P-S-N curve

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Automatic Train Operation Based on Adaptive Terminal Sliding Mode Control

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International Journal of Automation and computing 2015年第2期12卷 142-148页

作者： Peng Wu qing-yuan wang Xiao-Yun Feng School of Electrical Engineering Southwest Jiaotong University

This paper presents an adaptive terminal sliding mode control(ATSMC) method for automatic train operation. The criterion for the design is keeping high-precision tracking with relatively less adjustment of the control input. The ATSMC structure is designed by considering the nonlinear characteristics of the dynamic model and the parametric uncertainties of the train operation in real time. A nonsingular terminal sliding mode control is employed to make the system quickly reach a stable state within a finite time, which makes the control input less adjust to guarantee the riding comfort. An adaptive mechanism is used to estimate controller parameters to get rid of the need of the prior knowledge about the bounds of system uncertainty. Simulations are presented to demonstrate the effectiveness of the proposed controller, which has robust performance to deal with the external disturbance and system parametric uncertainties. Thereby, the system guarantees the train operation to be accurate and comfortable.

关键词： Automatic train operation track control terminal sliding mode control(TSMC) adaptive control comfortableness.

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Mechanical properties and fracture toughness of rail steels and thermite welds at low temperature

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International Journal of Minerals,Metallurgy and Materials 2012年第5期19卷 409-420页

作者： yuan-qing wang Hui ghold Yong-jiu Shi Bao-rui Feng Key Laboratory of Civil Engineering Safety and Durability of China Education Ministry Beijing 100084 China Department of Civil Engineering Tsinghua University Beijing 100084 China

Brittle fracture occurs frequently in rails and thermite welded joints, which intimidates the security and reliability of railway ser- vice. Railways in cold regions, such as qinghai-Tibet Railway, make the problem of brittle fi＇acture in rails even worse. A series of tests such as uniaxial tensile tests, Charpy impact tests, and three-point bending tests were carried out at low temperature to investigate the mechanical properties and fracture toughness of U71Mn and U75V rail steels and their thermite welds. Fracture micromechanisms were analyzed by scanning electron microscopy （SEM） on the fracture surfaces of the tested specimens. The ductility indices （percentage elongation aider frac- ture and percentage reduction of area） and the toughness indices （Charpy impact energy Ak and plane-strain fracture toughness Kic） of the two kinds of rail steels and the corresponding thermite welds all decrease as the temperature decreases. The thermite welds are more critical to fracture than the rail steel base metals, as indicated by a higher yield-to-ultimate ratio and a much lower Charpy impact energy. U71Mn rail steel is relatively higher in toughness than U75V, as demonstrated by larger Ak and Klc values. Therefore, U71Mn rail steel and the corresponding thermite weld are recommended in railway construction and maintenance in cold regions.

关键词： rails welds mechanical properties fracture toughness low temperature properties brittle fracture

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Wide color gamut switchable autostereoscopic 3D display based on directional quantum-dot backlight

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Chinese Physics B 2019年第12期28卷 191-201页

作者： Bin Xu Xue-Ling Li yuan-qing wang School of Electronic Science and Engineering Nanjing UniversityNanjing 210023China

A switchable autostereoscopic 3-dimensional(3D) display device with wide color gamut is introduced in this paper. In conjunction with a novel directional quantum-dot(QD) backlight, the precise scanning control strategy, and the eye-tracking system, this spatial-sequential solution enables our autostereoscopic display to combine all the advantages of full resolution,wide color gamut, low crosstalk, and switchable 2D/3D. And also, we fabricated an autostereoscopic display prototype and demonstrated its performances effectively. The results indicate that our system can both break the limitation of viewing position and provide high-quality 3D images. We present two working modes in this system. In the spatial-sequential mode,the crosstalk is about 6%. In the time-multiplexed mode, the viewer should wear auxiliary and the crosstalk is about 1%,just next to that of a commercial 3D display(BENQ XL2707-B and View Sonic VX2268 WM). Additionally, our system is also completely compatible with active shutter glasses and its 3D resolution is same as its 2D resolution. Because of the excellent properties of the QD material, the color gamut can be widely extended to 77.98% according to the ITU-R recommendation BT.2020(Rec.2020).

关键词： three-dimensional(3D) display directional and scanning quantum-dot backlight color gamut full resolution

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Response enhancement of olfactory sensory neurons-based biosensors for odorant detection

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2009年第4期10卷 285-290页

作者： Chun-sheng WU Pei-hua CHEN qing yuan Ping wang Biosensor National Special Laboratory MOE Key Laboratory of Biomedical Engineering Department of Biomedical Engineering Zhejiang University Hangzhou 310027 China

This paper presents a novel strategy for the response enhancement of olfactory sensory neurons (OSNs)-based biosensors by monitoring the enhancive responses of OSNs to odorants. An OSNs-based biosensor was developed on the basis of the light addressable potentiometric sensor (LAPS), in which rat OSNs were cultured on the surface of LAPS chip and served as sensing elements. LY294002, the specific inhibitor of phosphatidylinositol 3-kinase (PI3K), was used to enhance the responses of OSNs to odorants. The responses of OSNs to odorants with and without the treatment of LY294002 were recorded by LAPS. The results show that the enhancive effect of LY294002 was recorded efficiently by LAPS and the responses of this OSNs-LAPS hybrid biosensor were enhanced by LY294002 by about 1.5-fold. We conclude that this method can enhance the responses of OSNs-LAPS hybrid biosensors, which may provide a novel strategy for the bioelectrical signal monitor of OSNs in biosensors. It is also suggested that this strategy may be applicable to other kinds of OSNs-based biosensors for cellular activity detection, such as microelectrode array (MEA) and field effect transistor (FET).

关键词： Olfactory sensory neurons (OSNs) Response enhancement Light addressable potentiometric sensor (LAPS) Olfactory-based biosensor

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Biotribological behavior of ultra high molecular weight polyethylene composites containing bovine bone hydroxyapatite

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Journal of China University of Mining and Technology 2008年第4期18卷 606-612页

作者： LIU Jin-long ZHU yuan-yuan wang qing-liang GE Shi-rong School of Materials and Engineering China University of Mining ＆ Technology Xuzhou Jiangsu 221008 China

Wear particles of ultrahigh molecular weight polyethylene （UHMWPE） are the main cause of long-term failure of total joint replacements. Therefore, increasing its wear resistance or bioactivity will be very useful in order to obtain high quality artificial joints. In our study, UHMWPE composites filled with the bovine bone hydroxyapatite （BHA） were prepared by the method of compression moulding. A ball-on-disc wear test was carried out with a Universal Micro-Tribometer to investigate the friction and wear behavior of a Si3N4 ceramic ball, cross-sliding against the UHMWPE/BHA composites with human plasma lubrication. At the same time, the profiles of the worn grooves on the UHMWPE/BHA surface were scanned. The experimental results indicate that the addition of BHA to UHMWPE had a significant effect on the biotribological behavior of UHMWPE cross-sliding against the Si3N4 ceramic ball. The addition of BHA powder enhanced the hardness and modulus of elasticity of these composites and decreased the friction coefficients and wear rates under conditions of human plasma lubrication. When the added amount of BHA powders was up to 20%-30%, UHMWPE/BHA composites demonstrated the designed performance of the mechanical properties and biotribological behavior.

关键词： UHMWPE hydroxyapatite biotribology composite material

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Study on General Governing Equations of Computational Heat Transfer and Fluid Flow

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Communications in Computational Physics 2012年第10期12卷 1482-1494页

作者： wang Li Bo Yu Yi wang Xin-Ran wang qing-yuan wang Wen-Quan Tao Beijing Key Laboratory of Urban Oil and Gas Distribution Technology China University of PetroleumBeijing102249People’s Republic of China Key Laboratory of Thermal Fluid Science and Engineering of MOE Xi’an Jiaotong UniversityXi’an710049People’s Republic of China

The governing equations for heat transfer and fluid flow are often formulated in a general formfor the simplification of discretization and programming,which has achieved great success in thermal science and *** on the analysis of the popular general form of governing equations,we found that energy conservation cannot be guaranteed when specific heat capacity is not constant,which may lead to unreliable results.A new concept of generalized density is put forward,based on which a new general form of governing equations is proposed to guarantee energy conservation.A number of calculation examples have been employed to verify validation and feasibility.

关键词： SIMPLE algorithm general form of governing equations conservation generalized variable fluid-solid coupling

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Ultrasonic Fatigue Damage Behavior of 304L Austenitic Stainless Steel Based on Micro-plasticity and Heat Dissipation

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Journal of Iron and Steel Research International 2015年第7期22卷 638-644页

作者： Chao HE Ren-hui TIAN Yong-jie LIU Jiu-kai LI qing-yuan wang Key Laboratory of Energy Engineering Safety and Disaster Mechanics of Ministry of EducationCollege of Architecture and EnvironmentSichuan University

Very high cycle fatigue behavior （107 --109 cycles） of 304L austenitic stainless steel was studied with ultra- sonic fatigue testing system （20 kHz）. The characteristics of fatigue crack initiation and propagation were discussed based on the observation of surface plastic deformation and heat dissipation. It was found that micro-plasticity （slip markings） could be observed on the specimen surface even at very low stress amplitudes. The persistent slip mark- ings increased clearly along with a remarkable process of heat dissipation just before the fatigue failure. By detailed investigation using a scanning electron microscope and an infrared camera, slip markings appeared at the large grains where the fatigue crack initiation site was located. The surface temperature around the fatigue crack tip and the slip markings close to the fracture surface increased prominently with the propagation of fatigue crack. Finally, the cou- pling relationship among the fatigue crack propagation, appearance of surface slip markings and heat dissipation was analyzed for a better understanding of ultrasonic fatigue damage behavior.

关键词： very high cycle fatigue austenitic stainless steel micro-plasticity heat dissipation fatigue damage behavior

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Experimental study on the through-thickness properties of structural steel thick plate and its heat-affected zone at low temperatures

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2015年第3期16卷 217-228页

作者： yuan-qing wang Xiao-wei LIAO yuan-yuan ZHANG Yong-jiu SHI Key laboratory of Civil Engineering Safety and Durability of China Education Ministry Department of Civil Engineering Tsinghua University Beijing 100084 China

Lamellar tearing and crack-induced brittle failures along steel plates in the through-thickness direction seriously threaten the safety and reliability of steel thick plate structures in construction and service, especially at low ambient temperatures. Three kinds of tests, including uniaxial tensile tests, Charpy V-Notch impact tests, and three-point bending （TPB） tests were performed at normal and low temperatures to investigate the through-thickness mechanical properties, impact and fraclure toughness of Q345B structural steel plates with thicknesses from 60 to 165 mm. The test specimens were mainly sampled along the through-thickness direction of the plate, but transverse specimens along the rolling direction were also involved. The ductility index （percentage reduction of area）, impact toughness index （Charpy impact energy）, and fracture toughness index （critical crack tip opening displacement （CTOD） values） all decrease as the temperature declines. All the mechanical properties and the impact and fracture toughness along the through-thickness direction are worse than those along the rolling direction. The results also offer experimental support for the determination of an evaluation indicator for structural steel thick plates with through-thickness characteristics.

关键词： Structural steel thick plate Through-thickness properties Mechanical properties Impact toughness Fracturetoughness Low temperature

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