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      • KCI등재

        Exercise-mediated macrophage polarization modulates the targeted therapeutic effect of NAFLD: a review

        Li Zhenyu,Wang Ying,Tian Zhuang,Xie Yongchao,김재철 한국운동영양학회 2023 Physical Activity and Nutrition (Phys Act Nutr) Vol.27 No.3

        [Purpose] This review aims to explore the exercise-mediated hepatic macrophage polarization mechanism and its effect on improving and regulating non-alcoholic fatty liver disease (NAFLD) by analyzing the pathogenesis of NAFLD and the cause of the influence of hepatic macrophage polarization. In addition to exploring the varied effects of different exercise types on macrophage polarization regulation in NAFLD, to provide a direction and basis for the treatment of NA- FLD. [Methods] The research methodology involved a comprehensive search of the PubMed database using specific keywords such as “NAFLD”, “macrophage polarization”, and “exercise”, to retrieve relevant literature published. [Results] (1) The main factors inducing NAFLD were high-fat diet, obesity, insulin resistance (IR), changes in gut microbiota, and genetic variation in susceptibility. (2) Drug treatment, nutrient induction, microfactor induction, physiological environment induction, and other factors can induce the polarization of hepatic macrophages and affect NAFLD. (3) Different intensities, types, and frequencies of exercise have different effects on polarization macrophages, and may also differently effects improving liver inflammation, fibrosis, and NAFLD. Curently, regular moderate-intensity aerobic exercise is the most effective therapy for treating NAFLD. [Conclusion] Approaches to ameliorate NAFLD with exercise involve strategies to alter macrophage polarization by inhibiting M1 or driving M2 activation. However, research on the different types of exercise-mediated macrophage polarization mechanisms and differences in therapeutic effects is not yet sufficient. Future research is necessary to explore the exact mechanisms and differences in the effects of different exercises on the treatment of NAFLD.

      • Theoretical formulation for vehicle-bridge interaction analysis based on perturbation method

        Yongchao Tan,Liang Cao,Jiang Li 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.82 No.2

        A three-mass vehicle model including one rigid mass and two unsprung masses is adopted to predict the vehicle-bridge interaction (VBI) and to establish the nonlinear coupled governing equations. To overcome the numerical instability and large computation problems concerning the vehicle-bridge system, the perturbation method is used to convert the nonlinear coupled governing equations into a set of linear uncoupled equations. Formulas for bridge’s natural frequencies considering both the VBI and the dynamic responses of bridge and vehicle are proposed. Compared with the numerical results obtained by the Newmark-β method, the theoretical solutions for natural frequencies and dynamic responses are validated. The effects of the important factors of unsprung mass, vehicle damping, surface irregularity on the natural frequencies and dynamic responses of bridge and vehicle are discussed, based on the theoretical solutions.

      • KCI등재

        Developing homogeneous ion exchange membranes derived from sulfonated polyethersulfone/N-phthaloyl-chitosan for improved hydrophilic and controllable porosity

        Zhixue Li,Zhun Ma,Yuting Xu,Xiaomeng Wang,Yongchao Sun,Rong Wang,Jian Wang,Xueli Gao,Jun Gao 한국화학공학회 2018 Korean Journal of Chemical Engineering Vol.35 No.8

        Ion exchange membranes (IEMs) composed of sulfonated poly (ether sulfone) (SPES) and N-phthaloyl chitosan (NPHCs) were synthesized. NPHCs was employed in membrane fabrication to improve the porosity and hydrophilicity of membranes. The effect of blend ratio of sulfonation (DS) and NPHCs content on physico-chemical characteristics of home-made membranes was investigated. The morphology of prepared membranes was investigated by Fourier transform infrared spectroscopy (FTIR), X-ray diffractometer (XRD) and scanning electron microscopy (SEM). SEM images revealed the formation of a more porous membrane structure and smoother surface. The electrochemical and physical properties of CEMs were characterized comprising water content, contact angle, ion exchange capacity (IEC) and thermal stability. Membrane water content, surface hydrophilicity and IEC were enhanced with increase of DS and NPHCs blend ratios in casting solution. Furthermore, the diffusion coefficient was also improved slightly with increase of DS and NPHCs blend ratios in prepared membranes. Membrane potential, permselectivity, transport number and areal membrane resistance all showed decreasing trends by the increase in NPHCs blend ratio in casting solution. These results indicated that the prepared membrane has good prospective and great potential for desalination in electrodialysis applications.

      • Experimental studies on vibration serviceability of composite steel-bar truss slab with steel girder under human activities

        Liang Cao,Yongchao Tan,Jiang Li 국제구조공학회 2021 Steel and Composite Structures, An International J Vol.40 No.5

        In this study, the vibration serviceability of a composite steel-bar truss slab with steel girder system considering the human-structure interaction was investigated systematically through the on-site testing. Impulse excitations (heel-drop and jumping) and steady-state motions (walking and running) were performed to capture the primary vibration parameters (natural frequency, model shape, and damping ratio) and the distribution of peak accelerations. The composite floor possesses a low frequency of approximately 7.90 Hz and the damping ratio of ≈ 2.10%. The walking and running excitations by one person (single excitations) were considered to evaluate the vibration serviceability of the composite floor. The measured accelerations show a satisfactory vibration perceptibility. For design convenience and safety, a crest factor βrp (the ratio of peak acceleration to root-mean-square acceleration induced from an excitation) is proposed. Comparisons of the modal parameters determined from the tests (walking, running, heel-drop, and jumping) reveal there is an interaction exists between the human excitation and the composite floor. This interaction effect reduces the damping ratio of the composite floor.

      • KCI등재

        Comparative study on the Lower Silurian Longmaxi marine shale in the Jiaoshiba shale gas field and the Pengshui area in the southeast Sichuan Basin, China

        Lei Chen,Yongchao Lu,Jianqing Li,Xusheng Guo,Shu Jiang,Chan Luo 한국지질과학협의회 2020 Geosciences Journal Vol.24 No.1

        The Jiaoshiba shale gas field and Pengshui area are both located in the southeast Sichuan Basin with only 100 km apart. Although these two areas obtained shale gas flow from the Lower Silurian Longmaxi marine shale, there is a huge difference of production in these two areas where the Jiaoshiba shale gas field is more productive than the Pengshui area. In order to figure out the reason that caused this difference, this study analyzed the Longmaxi marine shale in these two areas by using drilling cores, and mineralogical and geochemical data. The results show that the Jiaoshiba shale gas field has a higher quality shale reservoir (higher content of quartz, higher porosity, higher permeability and higher TOC (Total Organic Carbon)) in the Lower Silurian Longmaxi Formation than that of the Pengshui area. The Lower Silurian Longmaxi marine shale in the Jiaoshiba shale gas field contains a higher total gas content (3.65 m3/ton in average) than that of the Pengshui area (1.19 m3/ton in average). Through structure analysis, this study found that the Jiaoshiba shale gas field and the Pengshui area located in the different tectonic units. The Jiaoshiba shale gas filed is located in the East Sichuan fold belt (wide spaced anticlines area) at the west side of the Qiyue mountain fault where less fractures are developed and the pressure coefficient is more than 1.5, resulting in much more free gas preserved in the shale reservoirs in the Lower Silurian Longmaxi Formation (the ratio of free gas content and absorbed gas content is 1.6), while the Pengshui area is located in the Hunan-Hubei-Guizhou thrust belt area at the east side of the Qiyue mountain fault where much more fractures are developed and the pressure coefficient is less than 1.0, leading to less free gas preserved in the Longmaxi marine shale (the ratio of free gas content and absorbed gas content is 0.6), that is why the shale reservoir in the Pengshui area has a lower total gas content than that in the Jiaoshiba shale gas field.

      • KCI등재

        Multi-strategy Remora Optimization Algorithm for solving multi-extremum problems

        Jia Heming,LI YONGCHAO,Wu Di,Rao Honghua,Wen Changsheng,Abualigah Laith 한국CDE학회 2023 Journal of computational design and engineering Vol.10 No.4

        A metaheuristic algorithm that simulates the foraging behavior of remora has been proposed in recent years, called ROA. ROA mainly simulates host parasitism and host switching in the foraging behavior of remora. However, in the experiment, it was found that there is still room for improvement in the performance of ROA. When dealing with complex optimization problems, ROA often falls into local optimal solutions, and there is also the problem of too-slow convergence. Inspired by the natural rule of “Survival of the fittest”, this paper proposes a random restart strategy to improve the ability of ROA to jump out of the local optimal solution. Secondly, inspired by the foraging behavior of remora, this paper adds an information entropy evaluation strategy and visual perception strategy based on ROA. With the blessing of three strategies, a multi-strategy Remora Optimization Algorithm (MSROA) is proposed. Through 23 benchmark functions and IEEE CEC2017 test functions, MSROA is comprehensively tested, and the experimental results show that MSROA has strong optimization capabilities. In order to further verify the application of MSROA in practice, this paper tests MSROA through five practical engineering problems, which proves that MSROA has strong competitiveness in solving practical optimization problems.

      • KCI등재

        Thermal error analysis, modeling and compensation of five-axis machine tools

        Zhi Huang,Yongchao Liu,Li Du,Han Yang 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.10

        The role of five-axis CNC machine tools (FAMT) in the manufacturing industry is becoming more and more important, but due to the large number of heat sources of FAMT, the thermal error caused by them will be more complicated. To simplify the complicated thermal error model, this paper presents a new modelling method for compensation of the thermal errors on a cradle-type FAMT. This method uses artificial neural network (ANN) and shark smell optimization (SSO) algorithm to evaluate the performance of FAMT, and developing the thermal error compensation system, the compensation model is verified by machining experiments. Generally, the thermal sensitive point screening is performed by a method in which a large number of temperature sensors are arranged randomly, it increases the workload and may cause omission of the heat sensitive point. In this paper, the thermal imager is used to screen out the temperature sensitive points of the machine tool (MT), then the temperature sensor is placed at the position of the heat sensitive point of the FAMT, and the collected thermal characteristic data is used for thermal error modeling. The C-axis heating test, spindle heating test, and the combined movement test are applied in this work, and the results show that the shark smell optimization artificial neural network (SSO-ANN) model was compared to the other two models and verified better performance than back propagation artificial neural network (BP-ANN) model and particle swarm optimization neural network (PSO) model with the same training samples. Finally, a compensation experiment is carried out. The compensation values, which was calculated by the SSO-ANN model are sent to the real-time error compensation controller. The compensation effect of the model is then tested by machining the ‘S’-shaped test piece. Test results show that the 32 % reduction in machining error is achieved after compensation, which means this method improves the accuracy and robustness of the thermal error compensation system.

      • KCI등재

        Temperature characteristics of indentation rolling resistance of belt conveyor

        Lidong Zhou,Zengfa Wu,Yongchao Li,Huiqiang Yao,Yuan Liu,Yuan Yuan,Wenjun Meng,Liangliang Han,Xueqin Cao 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.8

        In order to study the influence of temperature on the indentation rolling resistance of belt conveyor, theoretical analysis, numerical simulation analysis and experimental study of conveyor belt indentation rolling resistance with temperature characteristics were carried out in this paper, and the influence rules of different factors on the indentation rolling resistance of belt conveyor were obtained. First, the three-component Maxwell model is chosen as the viscoelastic model for the conveyor belt rubber material, and the viscoelastic modulus function based on temperature effects is constructed from the DMA experimental data fitting. Second, we introduce the one-dimensional Winkler foundation model to derive a mathematical expression for the indentation rolling resistance based on temperature properties. Then, a mathematical model of the indentation rolling resistance of a conveyor belt with temperature characteristics is developed in MATLAB and numerical simulations are performed. Finally, using the existing experimental equipment to conduct experiments, the experimental results are compared with the numerical simulation result. The results show that the theoretical numerical simulation results of the indentation rolling resistance with temperature effect presented in this paper have a consistent change trend with the experimental results; at constant temperature and constant load, the indentation rolling resistance increases with increasing band velocity; at constant temperature and constant velocity, the indentation rolling resistance increases with increasing load; at constant load and speed, when the temperature is lower than 0 °C or higher than 25 °C, the rolling resistance increases with the increase of temperature, when the temperature is between 0 °C and 25 °C, the rolling resistance decreases gradually with the increase of temperature.

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