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      • KCI등재

        Simultaneous optimization of ultrasound-assisted extraction for total flavonoid content and antioxidant activity of the tender stem of Triarrhena lutarioriparia using response surface methodology

        Qingming Cao,Jianye Yan,Zhicheng Sun,Limin Gong,Hongnian Wu,Shihan Tan,Yating Lei,Bo Jiang,Yuanqing Wang 한국식품과학회 2021 Food Science and Biotechnology Vol.30 No.1

        The asparagus of Triarrhena lutarioriparia (TL)is a popular vegetable with abundant chemical compoundsin China. This study aims to optimize the ultrasound-assistedextraction (UAE) method for its content of totalflavonoid and antioxidant activities by response surfacemethodology (RSM). Box-Behnken design was adopted toevaluate the influences of ethanol concentration, extractiontime and solvent-to-sample ratio on the extraction yield oftotal flavonoid and the antioxidant activity. Considering themaximum content of extracted total flavonoids andantioxidant activity, the optimal extraction conditions wereacquired with 70% (v/v) ethanol by UAE for 60 min at asolvent-to-sample ratio of 40 mL/g. The proportion of theextraction of total flavonoid was 15.88 mg/g and antioxidantactivity reached 79.53%. The RSM would be recommendedas an appropriate model for simultaneousoptimization of the UAE conditions for the content of totalflavonoid and the antioxidant activity of asparagus of TL.

      • Analysis of leaking ratio of sealing device for the intake port of EMC closed integral structure turbine disk through soft computing

        Cao, Yan,Zandi, Yousef,Rahimi, Abouzar,Fan, Qingming,Bai, Yu,Guo, Junde,Fu, Leijie,Khadimallah, Mohamed Amine,Jameel, Mohammed,Assilzadeh, Hamid Techno-Press 2021 Advances in nano research Vol.11 No.3

        The rotor disk produces an azimuthal velocity component in the space between the rotor and stator of a turbine disk, also known as the rim seal cavity. As part of an empirically study, the rim seal cavity is subjected to a test aimed to count the number of unstable structures and evaluate their rotational speed. An Electronic Control Unit (ECU) has a leak test aperture that is sealed by a sealing device that is selectively disposed in the leak test aperture. Designing pump and compressor machines and units requires the development of dependable seal assemblies that maintain tightness over a long period of time and in a wide variety of pressures and temperature. In the field of electrochemical machining (ECM), heat-resistant and high-strength materials may be machined into complicated forms using this well-known technology. ECM presents some issues as the electrochemical copying of grooves, insulating groove features, slots and mini-holes can cause water leakage due to the poor sealing device of the closed integral structure turbine disk. Sealing devices of rotor turbine disks are heavy components with low-cycle fatigue analysis to their life curves. However, there is rare analysis to detect their defects in various rotor regions (temperature, considering stress, mission profile). This study by use of hydro-thermal loading has attempted to focus on the mechanical seals rings and basic productive and operating requirements. Taking the damage and wear, the clearance has been altered that cause a raising in leakage. Generally, the leakage grows more rapidly than linearly with the after-damage clearance. Also, damage and wear were related to the labyrinth seal itself, resulting that the bending curvature and the percentage of bent tooth length were also relevant in defining the leakage in the case of bending damage.

      • KCI등재

        Mechanical analysis of functionally graded spherical panel resting on elastic foundation under external pressure

        Yan Cao,Xueming Qian,Qingming Fan,Farbod Ebrahimi 국제구조공학회 2020 Structural Engineering and Mechanics, An Int'l Jou Vol.74 No.2

        The main purpose of this study is to analyze the effects of external pressure on the vibration and buckling of functionally graded (FG) spherical panels resting of elastic medium. The material characteristics of the FG sphere continuously vary through the thickness direction based on the power-law rule. In accordance with first-order shear deformation shell theory and by the use of Ritz formulation the governing equations are presented. In this regard, the beam functions are applied in two-dimensions for different sets of boundary supports. The Winkler and Pasternak models of elastic foundations are also taken into account. In order to show the validity and applicability of the presented formulation, various comparison studies are given. Furthermore, a diverse range of numerical results is reported to check the impacts of geometrical and material parameters along with external pressure on the vibration and buckling analysis of FG spherical panels.

      • SCIESCOPUSKCI등재

        The JFNK method for the PWR's transient simulation considering neutronics, thermal hydraulics and mechanics

        He, Qingming,Zhang, Yijun,Liu, Zhouyu,Cao, Liangzhi,Wu, Hongchun Korean Nuclear Society 2020 Nuclear Engineering and Technology Vol.52 No.2

        A new task of using the Jacobian-Free-Newton-Krylov (JFNK) method for the PWR core transient simulations involving neutronics, thermal hydraulics and mechanics is conducted. For the transient scenario of PWR, normally the Picard iteration of the coupled coarse-mesh nodal equations and parallel channel TH equations is performed to get the transient solution. In order to solve the coupled equations faster and more stable, the Newton Krylov (NK) method based on the explicit matrix was studied. However, the NK method is hard to be extended to the cases with more physics phenomenon coupled, thus the JFNK based iteration scheme is developed for the nodal method and parallel-channel TH method. The local gap conductance is sensitive to the gap width and will influence the temperature distribution in the fuel rod significantly. To further consider the local gap conductance during the transient scenario, a 1D mechanics model is coupled into the JFNK scheme to account for the fuel thermal expansion effect. To improve the efficiency, the physics-based precondition and scaling technique are developed for the JFNK iteration. Numerical tests show good convergence behavior of the iterations and demonstrate the influence of the fuel thermal expansion effect during the rod ejection problems.

      • SCIESCOPUSKCI등재

        Resonance Elastic Scattering and Interference Effects Treatments in Subgroup Method

        Li, Yunzhao,He, Qingming,Cao, Liangzhi,Wu, Hongchun,Zu, Tiejun Korean Nuclear Society 2016 Nuclear Engineering and Technology Vol.48 No.2

        Based on the resonance integral (RI) tables produced by the NJOY program, the conventional subgroup method usually ignores both the resonance elastic scattering and the resonance interference effects. In this paper, on one hand, to correct the resonance elastic scattering effect, RI tables are regenerated by using the Monte Carlo code, OpenMC, which employs the Doppler broadening rejection correction method for the resonance elastic scattering. On the other hand, a fast resonance interference factor method is proposed to efficiently handle the resonance interference effect. Encouraging conclusions have been indicated by the numerical results. (1) For a hot full power pressurized water reactor fuel pin-cell, an error of about +200 percent mille could be introduced by neglecting the resonance elastic scattering effect. By contrast, the approach employed in this paper can eliminate the error. (2) The fast resonance interference factor method possesses higher precision and higher efficiency than the conventional Bondarenko iteration method. Correspondingly, if the fast resonance interference factor method proposed in this paper is employed, the $k_{inf}$ can be improved by ~100 percent mille with a speedup of about 4.56.

      • KCI등재

        Homogenized cross-section generation for pebble-bed type high-temperature gas-cooled reactor using NECP-MCX

        Qin Shuai,Li Yunzhao,He Qingming,Cao Liangzhi,Wang Yongping,Wu Yuxuan,Wu Hongchun 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.9

        In the two-step analysis of Pebble-Bed type High-Temperature Gas-Cooled Reactor (PB-HTGR), the lattice physics calculation for the generation of homogenized cross-sections is based on the fuel pebble. However, the randomly-dispersed fuel particles in the fuel pebble introduce double heterogeneity and randomness. Compared to the deterministic method, the Monte Carlo method which is flexible in geometry modeling provides a high-fidelity treatment. Therefore, the Monte Carlo code NECP-MCX is extended in this study to perform the lattice physics calculation of the PB-HTGR. Firstly, the capability for the simulation of randomly-dispersed media, using the explicit modeling approach, is developed in NECP-MCX. Secondly, the capability for the generation of the homogenized cross-section is also developed in NECP-MCX. Finally, simplified PB-HTGR problems are calculated by a two-step neutronics analysis tool based on Monte Carlo homogenization. For the pebble beds mixed by fuel pebble and graphite pebble, the bias is less than 100 pcm when compared to the high-fidelity model, and the bias is increased to 269 pcm for pebble bed mixed by depleted fuel pebble. Numerical results show that the Monte Carlo lattice physics calculation for the two-step analysis of PB-HTGR is feasible.

      • KCI등재

        Calculation of thermal neutron scattering data of MgF2 and its effect on beam shaping assembly for BNCT

        Hu Jiaqi,Qiao Zhaopeng,Fan Lunhe,Tang Yongqiang,Cao Liangzhi,Zu Tiejun,He Qingming,Li Zhifeng,Wang Sheng 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.4

        MgF2 as a moderator material has been extensively used in the beam shaping assembly (BSA) that plays an important role in the boron neutron capture therapy (BNCT). Regarded as important for applications, the thermal neutron scattering data of MgF2 were calculated, based on the phonon expansion model. The structural properties of MgF2 were researched by the VASP code based on the ab-initio methods. The PHONOPY code was employed to calculate the phonon density of states. Furthermore, the NJOY code was used to calculate the thermal neutron scattering data of MgF2. The calculated inelastic cross sections plus absorption cross sections are in agreement with the available experimental data. The neutron transport in the BSA has been simulated by using a hybrid Monte-Carlo-Deterministic code NECP-MCX. The results indicated that compared with the calculation of the free gas model, the thermal neutron flux and epithermal neutron flux at the BSA exit port calculated by using the thermal neutron scattering data of MgF2 were reduced by 27.7% and 8.2%, respectively.

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