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Evaluation of internal void related defects in reinforced concrete slab using electromagnetic wave properties

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Earthquake Engineering and Engineering Vibration 2024年第3期23卷 525-535页

作者： Minju kang Jinyoung hong Taemin Lee Doyun Kim Hajin Choi School of Architecture Soongsil UniversitySeoul 06978Republic of Korea

This study aims to develop a damage-detection algorithm based on the electromagnetic wave properties inside a reinforced concrete *** proposed method involves employing two algorithms based on data measured using ground-penetrating radar—a common electromagnetic wave method in civil *** possible defect area was identified based on the energy dissipated by the damage in the frequency-wavenumber domain,with the damage localized using the calculated relative permittivity of the *** proposed method was verified through a finite difference time-domain-based numerical analysis and a testing slab with artificial *** a result of verification,the proposed method quickly identified the presence of damage inside the concrete,especially for honeycomb-like defects located at the top of the *** study has practical significance in scanning structures over a large area more quickly than other non-destructive testing methods,such as ultrasonic methods.

关键词： GPR concrete defect electromagnetic wave relative permittivity non-destructive testing(NDT)

Jasmonic Acid is Induced in a Biphasic Manner in Response of Pea Seedlings to Wounding

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Journal of Integrative Plant Biology 2009年第6期51卷 562-573页

作者： Hao-ru Yang Ke Tang hong-Tao Liu Qiu-hong Pan Wei-Dong Huang College of Food Science and Nutritional Engineering China Agricultural University Beijing 100083 China Institute of Geographic Sciences and Natural Resources Research the Chinese Academy of Sciences Beijing 100101 China

The role of jasmonic acid （JA） in plant wounding response has been demonstrated. However, the source of JA in wound signaling remains unclear. In the present study, pea seedlings were used as material to investigate the systemic induction of JA and the activation of lipoxygenase （LOX）-dependent octadecanoid pathway upon wounding. The results showed that endogenous JA could induce two peaks in the wounded leaves and the stalks, while only one peak in the systemic leaves. LOX activity and its protein amount were also induced and the stimulation mainly occurred in the late phase, while one peak of induction was present after pretreatment with JA. Applied nordihydroguaiaretic acid （NDGA）, an inhibitor of LOX activity, only inhibited the induction of JA in the late phase, and the resistance of pea was impaired. Furthermore, 13（S）- hydroperoxy-9（Z）, 11 （E）-octadecadienoic acid （13（S）-H（P）ODE） was confirmed to be the main product of LOX throughout the experimental time. in addition, immunocytochemical analysis also revealed the occurrence of JA biosynthesis and transport upon wounding. These results demonstrated that wound-induced JA in wounded leaves resulted from its biosynthesis and conversion from its conjugates, while in systemic leaves resulted from its transport and biosynthesis; and proved that the LOX pathway was vital to the wound-induced defense response involved in JA biosynthesis.

关键词： defense response jasmonic acid lipoxygenase pea (Pisum sativum L.).

A Combined Reinforcement Learning and Model Predictive Control for Car-Following Maneuver of Autonomous Vehicles

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Chinese Journal of Mechanical Engineering 2023年第3期36卷 315-325页

作者： Liwen Wang Shuo Yang kang Yuan Yanjun Huang hong Chen School of Automotive Studies Tongji UniversityShanghai 201804China Shanghai Institute of Intelligent Science and Technology Tongji UniversityShanghai 201804China College of Electronic and Information Engineering Tongji UniversityShanghai 201804China

Model predictive control is widely used in the design of autonomous driving ***,its parameters are sensitive to dynamically varying driving conditions,making it difficult to be implemented into *** a result,this study presents a self-learning algorithm based on reinforcement learning to tune a model predictive ***,the proposed algorithm is used to extract features of dynamic traffic scenes and adjust the weight coefficients of the model predictive *** this method,a risk threshold model is proposed to classify the risk level of the scenes based on the scene features,and aid in the design of the reinforcement learning reward function and ultimately improve the adaptability of the model predictive controller to real-world *** proposed algorithm is compared to a pure model predictive controller in car-following *** to the results,the proposed method enables autonomous vehicles to adjust the priority of performance indices reasonably in different scenarios according to risk variations,showing a good scenario adaptability with safety guaranteed.

关键词： Model predictive control Reinforcement learning Autonomous vehicles

Investigation of Work Hardening Behavior of Inconel X-750 Alloy

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Acta Metallurgica Sinica(English Letters) 2017年第9期30卷 869-877页

作者： Pei-Tao Hua Wei-hong Zhang Lin-Jie Huan Wen-ru Sun Superalloys Division Institute of Metal Research ChineseAcademy of Sciences 110016 Shenyang China University of Chinese Academy of Sciences 100049 BeijingChina

The constant strain rate uniaxial compression tests were conducted in this paper for studying the work hardening behavior and revealing the underlying microstructure evolution involved in the plastic response of the nickel-based Inconel X-750 alloy. The work hardening rate versus true strain plots of Inconel X-750 alloy resembled that of low-stacking-fault energy （SFE） alloys with distinct four stages. The dislocations were found in the planar arrangements at a strain of 0.1 located at the onset of stage II, and the dislocation density was increased and the planar arrangement configuration was partially destroyed at a strain of 0.36 located in stage III. It was unexpected that deformation twins were observed at a strain of 0.69 located in stage IV although the alloy has been classified into materials with a higher SFE value. The result is different with a similar study, in which the deformation twins were absent in Ni-Cr-based alloy Inconel 625 even when the strain was as high as 0.65. It was deemed that the low level of solution strengthening favored the deformation of matrix and the activation of slip system for twining in Inconel X-750 alloy. Unlike the low-SFE alloys that the twins were always formed at the end of stage Ⅰ, the higher SFE delayed the twin formation to stage IV for Inconel X-750 alloy. The well- developed planar dislocation configuration gave rise to the stage Ⅱ with a slightly decreasing rate, the collapse of planar dislocation arrangements caused the occurrence of stage Ⅲ with an accelerated decreasing rate, and the twin formation led to the stage IV with a nearly constant work hardening rate.

关键词： Inconei X-750 alloy Work hardening behavior Planar dislocation arrangement Deformationtwins

Superior mechanical properties and strengthening mechanisms of lightweight AlxCrNbVMo refractory high-entropy alloys(x=0,0.5,1.0)fabricated by the powder metallurgy process

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Journal of Materials Science & Technology 2021年第10期69卷 32-41页

作者： Byungchul kang Taeyeong Kong Ho Jin Ryu Soon Hyung hong Department of Material Science and Engineering Korea Advanced Institute of Science and Technology(KAIST)291 Daehak-roYuseong-guDaejeon 34141Republic of Korea Department of Nuclear and Quantum Engineering Korea Advanced Institute of Science and Technology(KAIST)291 Daehak-roYuseong-guDaejeon 34141Republic of Korea

Light and strong AlxCrNbVMo(x=0,0.5,and 1.0)refractory high-entropy alloys(RHEAs)were designed and fabricated via a the powder metallurgical *** microstructure of the AlxCrNbVMo alloys consisted of a single BCC crystalline structure with a sub-micron grain size of 2-3μm,and small amounts(ructure,without chemical segregation or micropores was achieved via high-energy ball milling and spark-plasma *** alloys exhibited superior mechanical properties at 25 and 1000℃compared to those of other ***,CrNbVMo alloy showed a yield strength of 2743 MPa at room ***,the yield strength of the CrNbVMo alloy at 1000℃was 1513 *** specific yield strength of the CrNbVMo alloy was increased by 27%and 87%at 25 and 1000℃,respectively,compared to the AlMo_(0.5) NbTa_(0.5)TiZr RHEA,which exhibited so far the highest specific yield strength among the cast *** addition of Al to CrNbVMo alloy was advantageous in reducing its reduce density to below 8.0 g/cm^(3),while the elastic modulus decreased due to the much lower elastic modulus of Al compared to that of the CrNbVMo *** analysis of the strengthening contributions,showed that the solid solution strengthening,arising from a large misfit effect due to the size and modulus,and the high shear modulus of matrix,was revealed to predominant strengthening mechanism,accounting for over 50%of the yield strength of the AlxCrNbVMo RHEAs.

关键词： High-entropy alloy Powder metallurgy Refractory Strengthening mechanisms Oxide dispersoids

Clinical Significance of REM Sleep Behavior Disorders and Other Non-motor Symptoms of Parkinsonism

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Neuroscience Bulletin 2017年第5期33卷 576-584页

作者： hong Jin Jin-ru Zhang Yun Shen Chun-Feng Liu Department of Neurology and Sleep Center The Second Affiliated Hospital of Soochow University Institute of Neuroscience Soochow University

Rapid eye movement sleep behavior disorder （RBD） is one of the most common non-motor symptoms of parkinsonism, and it may serve as a prodromal marker of neurodegenerative disease. The mechanism underlying RBD is unclear. Several prospective studies have reported that specific non-motor symptoms predict a conversion risk of developing a neurodegenerative disease, including olfactory dysfunction, abnormal color vision, autonomic dysfunction, excessive daytime sleepiness, depression, and cognitive impairment. Parkinson＇s disease （PD） with RBD exhibits clinical heterogeneity with respect to motor and non-motor symptoms compared with PD without RBD. In this review, we describe the main clinical and pathogenic features of RBD, focusing on its association with other non-motor symptoms of parkinsonism.

关键词： Parkinson's disease · Rapid eye movement sleep behavior disorder · Risk factors ·Parkinsonism

Spatial–temporal distribution and potential ecological risk assessment of nonylphenol and octylphenol in riverine outlets of Pearl River Delta, China

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Journal of Environmental Sciences 2014年第11期26卷 2340-2347页

作者： ru Chen Pinghe Yin Ling Zhao Qiming Yu Aihua hong Shunshan Duan Department of Chemistry College of Life Science and Technology Jinan University Center of Analysis and Test Department of Environmental Engineering Jinan University Griffith School of Engineering Griffith University Nathan Campus Brisbane Queensland 4111 Australia Center of Analysis and Test Guangzhou Research Center of Hydrobiology College of Life Science and TechnologyJinan University

The aquatic environments of the Pearl River Delta in Southern China are subjected to contamination with various industrial chemicals from local industries. In this paper, the occurrence, seasonal variation and spatial distribution of alkylphenol octylphenol （OP） and nonylphenol （NP） in fiver surface water and sediments in the runoff outlets of the Pearl River Delta were investigated. NP and OP were detected in all water and sediment samples and their mean concentrations in surface water during the dry season ranged from 810 to 3366 ng/L and 85.5 to 581 ng/L, respectively, and those in sediments ranged from 14.2 to 95.2 ng/g dw and 0.4 to 3.0 ng/g dw, respectively. In surface water, much higher concentrations were detected in the dry season than those in the wet season. In sediments, the concentrations in the dry season were also mostly higher. High concentrations of NP and OP were found in Humen outlet, likely due to high levels of domestic and industrial wastewater discharges. An ecological risk assessment with the use of hazard quotient （HQ） was also carried out and the HQvalues ranged from 3.6 × 10^-5 to 35 and 64% of samples gave a HQ 〉 1, indicating that the current levels of NP and OP pose a significant risk to the relevant aquatic organisms in the region.

关键词： Nonylphenol Octylphenol Environmental concentration Ecological risk assessment Pearl River Delta

Effect of pre-tensioned rock bolts on stress redistribution around a roadway—insight from numerical modeling

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Journal of China University of Mining and Technology 2008年第4期18卷 509-515页

作者： GAO Fu-qiang kang hong-pu Mining and Designing Branch Central Coal Research Institute Beijing 100013 China

The importance of the pre-tensioned force of rock bolts has been recognized by more and more researchers. To investi- gate the effect of pre-tensioned rock bolts on stress redistribution around roadways, a numerical analysis was carried out using FLAC3D and a special post-process methodology, using surfer, is proposed to process the numerical simulation results. The results indicate that pre-tensioned rock bolts have a significant effect on stress redistribution around a roadway. In the roof, pre-tensioned rock bolts greatly increase vertical stress; as a result, the strength of the rock mass increased significantly which results in a greater capacity of bearing a large horizontal stress. The horizontal stress decreases in the upper section of the roof, indicating that pre-tensioned rock bolts significantly reduce the coefficient and the size of the region concentration of horizontal stress. At the lat- eral side, pre-tensioned rock bolts greatly increase the horizontal stress; therefore, the rock mass strength significantly increases which results also in a greater capacity of bearing a large vertical stress. The greater the size of pre-tensioned force, the larger the region of stress redistribution around a roadway is affected and the higher the size of the stress on the roadway surface the more the rock mass strength increases.

关键词： pre-tensioned rock bolts stress redistribution numerical simulation

Application status and comparison of dioxin removal technologies for iron ore sintering process

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Journal of Iron and Steel Research International 2018年第4期25卷 357-365页

作者： hong-ming Long Qi Shi hong-liang Zhang ru-fei Wei Tie-jun Chun Jia-xin Li Key Laboratory of Metallurgical Emission Reduction & Resources Recycling Ministry of Education Anhui University of Technology Ma'anshan 243002 Anhui China School of Metallurgical Engineering Anhui University of Technology Ma'anshan 243002 Anhui China

The emission of dioxins from the iron ore sintering process is the largest emission source of dioxins, and the reduction in dioxin emission from the iron ore sintering process to the environment is increasingly important. Three approaches to control the emission of dioxins were reviewed： source control, process control, and terminal control. Among them, two terminal control technologies, activated carbon adsorption and selective reduction technology, were discussed in detail. Following a comparison of the reduction technologies, the terminal control method was indicated as the key technology to achieve good control of dioxins during the sintering process. For the technical characteristics of the sintering process and flue gas, multiple methods should be collectively considered, and the most suitable method may be addition of inhibitors ＋ ultra-clean dust collection （electrostatic precipitation/bag filter）＋ desulphurization ＋ selective catalytic reduction to sufficiently remove multiple pollutants, which provides a direction for the cooperative disposal of flue gas pollutants in future.

关键词： Iron ore sintering process Dioxins Removal technology Activated carbon adsorption Selective catalyticreduction