Analysis and research on teeth thermodynamic coupling contact of gear transmission system

Wang, Xigui,Wang, Yongmei,Zhao, Xuezeng,Li, Xinglin Techno-Press 2015 Coupled systems mechanics Vol.4 No.3

In the gear meshing process, gear temperature field concerns the meshing surface friction, the friction heat depends on the contact pressure, the contact pressure is affected by the elastic deformation of gears and the temperature field caused by the thermal deformation, so the temperature field, stress field and displacement field should be mutual coupling. It is necessary to consider in meshing gear pair in the operation process of thermodynamic coupling contact stress (TCCS) and thermodynamic coupling deformation (TCD), and based on thermodynamic coupling analysis (TCA) of gear teeth deformation.

TEM fitting considering TEPs of contact interface of meshing gear

Xigui Wang,Siyuan An,Yongmei Wang,Jiafu Ruan,ShuE Ji 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.10

This topic aims to clarify the method of optimizing tooth surface modification (TSM) fitting under thermoelastic lubrication (TEL) conditions to reveal the most popular and concerning mechanism issues in mechanical engineering. A traditional TSM numerical method has played an increasingly important role in our basic understanding of thermoelastic properties (TEPs) under TEL conditions, which is undoubtedly affirmative and effective. This subject involves the TSM fitting of the theoretical tooth surface superimposed structure, and performs 3D and diagonal modification optimization design, obtains the modified surface position and normal vectors, a variety of optimized modification models are established and complex curved surfaces are analyzed to fit the actual Interface thermoelastic contact numerical simulation, which has been further demonstrated and expressed in actual key working conditions and multiple influencing parameters, thereby reducing transmission error and vibration noise in order to improve gear meshing thermoelastic anti-scuffing load-bearing performance (TEASLBP).

Multi-objective optimization modification of a tooth surface with minimum of flash temperature and vibration acceleration RMS

Xigui Wang,Yongmei Wang,Yixiang Liu,Xinbo Zhang,Dayu Zheng 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.7

The minimum of tooth surface flash temperature and vibration acceleration RMS design is proposed and analyzed. The tooth contact analysis (TCA) and the load tooth contact analysis (LTCA) method and multi-objective optimization are also detailed. Satisfying design variables in multiple physical quantities leads to the minimum of multi-objective optimization. Considering the tooth surface loading conditions are uniform or not, the optimal modification of the tooth surface for improving gear comprehensive characteristics under various load bearing conditions is improved. The tooth surface flash temperature and vibration acceleration root mean square (RMS) values in different transmission modes of marine ship power rear gears drive system are derived. This research considers the multi-objective optimization modifications of tooth surface, and its main purpose is to propose an approach to help design tooth corrections to simultaneously optimize several objective physical quantities.

Study on super-harmonic resonance for gear transmission based on teeth surface friction

Xigui Wang,Yongmei Wang,Xuezeng Zhao,Xinglin Li 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.11

Gear backlash and time-varying nonlinear meshing stiffness are the key design attributes of modern warship planetary gear transmission. The transmission prominent concern is teeth surface friction dynamics affect behavior and way. Therefore, the change of directionin meshing process, teeth surface friction will generate a larger oscillation, excitation response and energy consumption ways to affectdynamic characteristics of planetary gear transmission, which makes response range, dynamic behaviors more complex. Gear model andmulti scale equations for transmission are established, analyzing incentive role teeth surface friction when considering dynamic and staticload on influence law of gear resonance frequency response.

Atomic Force Microscopy of Asymmetric Membranes from Turtle Erythrocytes

Yongmei Tian,Mingjun Cai,Haijiao Xu,Bohua Ding,Xian Hao,Junguang Jiang,Yingchun Sun,Hongda Wang 한국분자세포생물학회 2014 Molecules and cells Vol.37 No.8

The cell membrane provides critical cellular functions that rely on its elaborate structure and organization. The structure of turtle membranes is an important part of an ongoing study of erythrocyte membranes. Using a combination of atomic force microscopy and single-molecule force spectroscopy, we characterized the turtle erythrocyte membrane structure with molecular resolution in a quasi-native state. High-resolution images both leaflets of turtle erythrocyte membranes revealed a smooth outer membrane leaflet and a protein covered inner membrane leaflet. This asymmetry was verified by single-molecule force spectroscopy, which detects numerous exposed amino groups of membrane proteins in the inner membrane leaflet but much fewer in the outer leaflet. The asymmetric membrane structure of turtle erythrocytes is consistent with the semi-mosaic model of human, chicken and fish erythrocyte membrane structure, making the semi-mosaic model more widely applicable. From the perspective of biological evolution, this result may support the universality of the semi-mosaic model.

Malnutrition worsens fluorosis-induced damage in hypothalamic-pituitary-ovarian axis of rats

Yongmei Liu,Ling Li,Jingfeng Xu,Siwen Yu,Shijun Wang,Maojuan Yu,Wenbing Zou,Mingliang Cheng,Shuhua Xia 대한독성 유전단백체 학회 2019 Molecular & cellular toxicology Vol.15 No.2

Backgrounds: This study aimed to evaluate the effects of malnutrition on the hypothalamic-pituitary-ovarian axis (HPOA) sex hormones in female rats with coal burning-type fluorosis. Methods: Female rats were divided into four groups: control, malnutrition, fluorosis, and fluorosis with malnutrition. Rats in the control and malnutrition groups were fed pollution-free corn with either regular or low protein content. Rats in the fluorosis and fluorosis with malnutrition groups were fed corn roasted with coals from the fluorosis endemic areas of Zhijin, China,with either regular or low protein content. Results: Results revealed that the body weight of rats with protein malnutrition was significantly reduced compared with that of the control and fluorosis rats. Urinary fluoride was significantly decreased and bone fluoride was significantly increased in the fluorosis with malnutrition group compared to the fluorosis group. Moreover, protein malnutrition significantly enhanced the effect of fluoride on gonadotropin-releasing hormone, follicle-stimulating hormone, luteinizing hormone, and testosterone. Histological and ultrastructural analyses revealed that protein malnutrition intensified fluoride-induced ovary damage. Conclusion: Malnourishment could promote the abnormal secretion of HPOA sex hormones in females with fluorosis.

Atomic Force Microscopy of Asymmetric Membranes from Turtle Erythrocytes

Tian, Yongmei,Cai, Mingjun,Xu, Haijiao,Ding, Bohua,Hao, Xian,Jiang, Junguang,Sun, Yingchun,Wang, Hongda Korean Society for Molecular and Cellular Biology 2014 Molecules and cells Vol.37 No.8

The cell membrane provides critical cellular functions that rely on its elaborate structure and organization. The structure of turtle membranes is an important part of an ongoing study of erythrocyte membranes. Using a combination of atomic force microscopy and single-molecule force spectroscopy, we characterized the turtle erythrocyte membrane structure with molecular resolution in a quasi-native state. High-resolution images both leaflets of turtle erythrocyte membranes revealed a smooth outer membrane leaflet and a protein covered inner membrane leaflet. This asymmetry was verified by single-molecule force spectroscopy, which detects numerous exposed amino groups of membrane proteins in the inner membrane leaflet but much fewer in the outer leaflet. The asymmetric membrane structure of turtle erythrocytes is consistent with the semi-mosaic model of human, chicken and fish erythrocyte membrane structure, making the semi-mosaic model more widely applicable. From the perspective of biological evolution, this result may support the universality of the semi-mosaic model.

Prognostic value of Nrf2/HO-1 expression and its correlation with occurrence in esophageal squamous cell carcinoma

Gao Yongmei,Li Mengyan,Wang Bo,Ma Yuqing 한국유전학회 2023 Genes & Genomics Vol.45 No.6

Background Esophageal squamous cell carcinoma (ESCC) is thought to be started and developed by genes associated with inflammation. A cancer's ability to spread and grow can be aided by nuclear factor erythroid-2 related factor 2 (Nrf2) hyperactivation, which can also make a tumor more resistant to chemotherapy and radiation treatment. However, it is still unknown how Nrf2 gene expression affects ESCC prognosis and controls function throughout ESCC advancement. Objective The expression of Nrf2 and HO-1 in ESCC and precancerous esophageal precancerous lesions was analyzed, and their relationship with esophageal squamous cell carcinoma was analyzed. Methods Immunohistochemistry (IHC) was used to confirm the expression of Nrf2 and heme oxygenase-1 (HO-1) proteins in tissue microarrays from Chinese populations with ESCC. We looked at the connections between Nrf2/HO-1 expression and invading immune cells using the TIMER database. Results Ethnicity and N stage are associated with Nrf2 overexpression. Differentiation, N stage, vascular invasion, distant metastasis, and American Joint Committee on Cancer (AJCC) staging are all associated with HO-1 overexpression. The expression of Nrf2 and HO-1 had a favorable correlation. Patients with elevated Nrf2 and HO-1 expression had lower progression-free survival (PFS) and overall survival (OS). In high-grade intraepithelial neoplasia, Nrf2 and HO-1 expression generally occurred, partially in low-grade intraepithelial neoplasia specimens, and rarely in normal mucosa. We further show that Nrf2 suppression is linked to higher immunological marker expression and lower immune cell infiltration. Conclusion The prognosis of ESCC may be improved by inhibiting the expression of Nrf2 and HO-1. A lack of immune cells was seen in ESCC with Nrf2 impairment.

A QoS-aware Adaptive Coloring Scheduling Algorithm for Co-located WBANs

( Jingxian Wang ),( Yongmei Sun ),( Shuyun Luo ),( Yuefeng Ji ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.12

Interference may occur when several co-located wireless body area networks (WBANs) share the same channel simultaneously, which is compressed by resource scheduling generally. In this paper, a QoS-aware Adaptive Coloring (QAC) scheduling algorithm is proposed, which contains two components: interference sets determination and time slots assignment. The highlight of QAC is to determine the interference graph based on the relay scheme and adapted to the network QoS by multi-coloring approach. However, the frequent resource assignment brings in extra energy consumption and packet loss. Thus we come up with a launch condition for the QAC scheduling algorithm, that is if the interference duration is longer than a threshold predetermined, time slots rescheduling is activated. Furthermore, based on the relative distance and moving speed between WBANs, a prediction model for interference duration is proposed. The simulation results show that compared with the state-of-the-art approaches, the QAC scheduling algorithm has better performance in terms of network capacity, average delay and resource utility.

Development of Hospice Care Service for the Elderly in China

Du Peng,Wang Yongmei 서울대학교 사회발전연구소 2016 Journal of Asian Sociology Vol.45 No.2

Against the backdrop of the aging society, we need to make great efforts to develop the hospice care service for the elderly if we want to comprehensively improve “the Quality of Death” and enable more old people to enjoy benefits of dying peacefully. This essay firstly reviews the policies and practices of the development of hospice care for the elderly in China, and we discover that main obstacles that hinder its development are institutional barriers, difficulties in financing, a lack of personnel, and low acceptance rate of the general public. Considering the current construction of socialized pension service system in China, we make institutional exploration in the development of the hospice care of the elderly in China. And we hold that these are key ways to develop this career to “get through” the lifeblood of the medical and health services and the hospice care service, “extend” the socialized system of elderly care service to this service, enhance the “input” in this service, and fully develop the long-acting “safeguard” mechanism for the development of this service.