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Molecular mechanisms of 1,2-dichloroethane-induced neurotoxicity
Xiang Yang,Zhang Xiaoshun,Tian Zhiling,Cheng Yibin,Liu Ningguo,Meng Xiaojing 한국독성학회 2023 Toxicological Research Vol.39 No.4
The production of industrial solvents and adhesives often utilizes 1,2-dichloroethane (1,2-DCE), a highly toxic halogenated hydrocarbon compound. Occupational 1,2-DCE poisoning occurs frequently and is a public health concern. Exposure to 1,2-DCE can damage the brain, liver, and kidneys. The main and most severe damage caused by exposure to 1,2-DCE is to the nervous system, especially the central nervous system. Current research on 1,2-DCE mainly focuses on the mechanism of brain edema. Several possible mechanisms of 1,2-DCE neurotoxicity have been proposed, including oxidative stress, calcium overload, blood–brain barrier damage, and neurotransmitter changes. This article reviews the research progress on 1,2-DCE neurotoxicity and the mechanism behind it to provide a scientific basis for the prevention and treatment of 1,2-DCE poisoning.
Xiangyang Zhang,Vahid Bayat,Mohammadreza Koopialipoor,Danial Jahed Armaghani,Weixun Yong,Jian Zhou 국제구조공학회 2020 Smart Structures and Systems, An International Jou Vol.26 No.3
Structural damage to an arch dam is often of major concern and must be evaluated for probable rehabilitation to ensure safe, regular, normal operation. This evaluation is crucial to prevent any catastrophic or failure consequences for the life time of the dam. If specific major damage such as a large crack occurs to the dam body, the assessments will be necessary to determine the current level of safety and predict the resistance of the structure to various future loading such as earthquakes, etc. This study investigates the behavior of an arch dam cracked due to water pressure. Safety factors (SFs), of shear and compressive tractions were calculated at the surfaces of the contraction joints and the cracks. The results indicated that for cracking with an extension depth of half the thickness of the dam body, for both cases of penetration and non-penetration of water load into the cracks, SFs only slightly reduces. However, in case of increasing the depth of crack extension into the entire thickness of the dam body, the friction angle of the cracked surface is crucial; however, if it reduces, the normal loading SFs of stresses and joints tractions reduce significantly.
Xiangyang Xu,Xupeng Fan,Peng Diao,Huaiju Liu 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.7
A new gear tooth modification model of planetary gear system was established by considering the characteristics of tooth longitudinal crowning modification and tooth profile modification. Using this model, the influences of modification parameters on the time-varying mesh stiffness, transmission error, contact spots and dynamic response of the planetary gear system were analyzed through numerical analysis. The results show that tooth profile modification can effectively restrain the mesh stiffness sudden variation in the single and double tooth alternation of both the internal and external mesh pairs, and significantly decrease the transmission error fluctuation. However, longitudinal crowning modification has no marked influence on mesh stiffness sudden variation or transmission error fluctuation. The tooth profile modification can significantly reduce the sudden variation of tooth surface load during gear mesh course. Longitudinal crowning modification can make the tooth surface load evenly distributed in tooth width direction. When the external meshing pairs are modified at the tooth profile individually, the magnitude values of main response resonance peaks of internal meshing pairs have a great reduction, but those values of external meshing pairs change slightly. In the case of tooth profile modification of the internal meshing pairs, the phenomenon is reversed. By contrast with tooth profile modification, longitudinal crowning modification has little influence on the resonance peaks of internal and external meshing pairs.
Time-varying Group Formation With Leader-following Control for Heterogeneous Multi-agent Systems
Xiangyang Du,Weixun Li,Jingyu Xiao,Zengqiang Chen 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.7
This paper studies time-varying group formation control for heterogeneous multi-agent systems (MAS). Two subgroups of heterogeneous MAS consisting of second-order dynamic and Euler-Lagrange (E-L) dynamic agents, three subgroups of heterogeneous MAS consisting of first-order, second-order dynamic and E-L dynamic agents are considered respectively. Firstly, through the assumption of the formation-tracking feasibility condition and the design of the formation compensation vectors in the controller, the time-varying formation control can be transformed into a consensus problem. Then, a distributed controller based on neighbor information is designed and sufficient conditions for time-varying formation control are obtained. The time-varying group formation problem of heterogeneous MAS is analyzed by Lyapunov stability theory and eigenvalue theory. Finally, two simulation results show that the proposed controller can realize the time-varying formation control of heterogeneous group MAS.
Xiangyang Zhou,Yanjun Shi,Lingling Li,Rui-fang Yu,Libo Zhao 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.6
This paper presents a high precision compound control scheme based on non-singular terminal sliding mode and extended state observer (ESO) for an aerial inertially stabilized platform (ISP) to suppress the effects of multi-source disturbances on the control performance of the ISP. Firstly, a non-singular terminal sliding mode controller is proposed to achieve high disturbance rejection ability, by which the multi-source disturbances are integrally suppressed as an aggregate disturbance. And then, to restrain the chattering effect of the sliding mode control, a disturbance compensation scheme based on the extended state observer is proposed. By the ESO, the disturbances are observed and compensated in real time and hence the chattering effect is significantly alleviated. Meanwhile, a parameter configuration method is proposed to simplify the ESO design. To verify the method, simulations and experiments are conducted. The results show that the proposed compound control scheme has excellent ability in both disturbance rejection and chattering reduction, by which the stabilization precision of the ISP is improved significantly.
THE INTEGRATION OF CAD/CAM/CAE BASED ON MULTI MODEL TECHNOLOGY IN THE DEVELOPMENT OF CYLINDER HEAD
Xiangyang Xu,Ulrich Weiss,Guoan Gao 한국자동차공학회 2002 International journal of automotive technology Vol.3 No.2
The integration of CAD/CAM/CAE in product development is the key to realize concurrent engineering.<br/> Generally, different systems are employed in product development departments. These different systems create a lot of troubles such as difficulty in communication, misunderstanding and so on. A new approach to integrate CAD/CAM/CAE in one system based on CATIA for the end-to-end process in cylinder head development is presented. Multi Model Technology (MMT) is used to create consistent and associated CAD models for the end-to-end process in cylinder head development. The concept and method to create and organize multi models are discussed. A typical four-layer structure of MMT for mechanical products is defined. The multi level structure of the cylinder head models based on MMT is provided. The CAD models of cylinder head created based on MMT can be used as the consistent model. All models in the downstream of cylinder head development such as structure analysis, CFD, sand core design, casting simulation and so on are associated with the CAD models. Practice shows the approach in this paper enables the development process to be carried concurrently and can obviously shorten time to the market, reduce product cost and improve product quality.
Rolling bearing fault convolutional neural network diagnosis method based on casing signal
Xiangyang Zhang,Guo Chen,Tengfei Hao,Zhiyuan He 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.6
Affected by the transmission path, it is very difficult to diagnose the vibration signal of the rolling bearing on the aircraft engine casing. A fault diagnosis method based on convolutional neural network is proposed for the weak vibration signal of the casing under the excitation of rolling bearing fault. Firstly, the processing method of vibration signal is studied. Through comparison and analysis, it is found that the fault characteristics of rolling bearing are more easily expressed by continuous wavelet scale spectrum, and a better recognition rate is obtained. Finally, the experiment was carried out with an aero-engine rotor tester with a casing, and the method based on wavelet scale spectrum and convolutional neural network was used for diagnosis. The results were compared with the support vector machine method. The results show that the method has a high recognition rate for the weak fault signals of different fault types collected on the aero engine case, and its fault recognition rate reaches 95.82 %, which verifies the superiority and potential of the method for rolling bearing fault diagnosis.
The nonlinear effects of flexible pins on wind turbine gearboxes
Xiangyang Xu,Shaojiang Dong,Jiayuan Luo,Tianhong Luo 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.8
The structure of flexible pin-type planetary gear systems used in wind turbine gearboxes can improve the load sharing ability of planetswhile saving space unlike straddle-type carriers. However, the nonlinear dynamic characteristic of this type of system is not fully developed. This work presents a coupled lumped-parameter dynamic model to demonstrate nonlinear effects. Gear contact loss nonlinearityand bearing clearance nonlinearity are integrated into this dynamical model, and the effects of flexible pins on the nonlinear dynamicresponses are discussed. The conclusions made are as follows: lower flexible pin stiffness can significantly reduce nonlinear effects;when pin stiffness is increased, contact loss still occurs in positions of strong vibration even if the planet gear bearings have higher ordersof magnitude of tangential load in the wind turbine gearbox; dynamic response peaks are asymmetric with a frequency sweep; only leftoblique "Soft" jumps occur, and the right oblique “Hard” jump phenomena rarely occur; planet gear supporting the bearing clearanceexists; and vibration chaos occurs in positions of strong vibration.
Xiangyang Xu,Jiang Daibo,Hateo Gou 국제구조공학회 2022 Steel and Composite Structures, An International J Vol.45 No.6
Geopolymer concrete ( ) has emerged as a feasible choice for construction materials as a result of the environmental issues associated with the production of cement. The findings of this study contribute to the development of machine learning methods for estimating the properties of eco-friendly concrete to help reduce 2 emissions in the construction industry. The compressive strength ( ) of is predicted using artificial intelligence approaches in the present study when ground granulated blast-furnace slag ( ) is substituted with natural zeolite ( ), silica fume ( ), and varying concentrations. For this purpose, two machine learning methods multi-layer perceptron ( ) and radial basis function ( ) were considered and hybridized with arithmetic optimization algorithm ( ), and grey wolf optimization algorithm ( ). According to the results, all methods performed very well in predicting the of . The proposed − might be identified as the outperformed framework, although other methodologies ( − , − , and − ) were also reliable in the of forecasting process.