Thermodynamic simulation and structural optimization of the collimator in the drift duct of EAST-NBI

Tang Ning,Hu Chun-dong,Xie Yuan-lai,Wei Jiang-long,Cui Zhi-Wei,Xie Jun-Wei,Pan Zhuo,Jiang Yao 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.11

The collimator is one of the high-heat-flux components used to avoid a series of vacuum and thermal problems. In this paper, the heat load distribution throughout the collimator is first calculated through experimental data, and a transient thermodynamic simulation analysis of the original model is carried out. The error of the pipe outlet temperature between the simulated and experimental values is 1.632%, indicating that the simulation result is reliable. Second, the model is optimized to improve the heat transfer performance of the collimator, including the contact mode between the pipe and the flange, the pipe material and the addition of a twisted tape in the pipe. It is concluded that the convective heat transfer coefficient of the optimized model is increased by 15.381% and the maximum wall temperature is reduced by 16.415%; thus, the heat transfer capacity of the optimized model is effectively improved. Third, to adapt the long-pulse steady-state operation of the experimental advanced superconducting Tokamak (EAST) in the future, steady-state simulations of the original and optimized collimators are carried out. The results show that the maximum temperature of the optimized model is reduced by 37.864% compared with that of the original model. The optimized model was changed as little as possible to obtain a better heat exchange structure on the premise of ensuring the consumption of the same mass flow rate of water so that the collimator can adapt to operational environments with higher heat fluxes and long pulses in the future. These research methods also provide a reference for the future design of components under high-energy and long-pulse operational conditions

Association between Glutathione S-Transferase T1, M1, and P1 Genotypes and the Risk of Colorectal Cancer

Ning Cong,Lisheng Liu,Ying Xie,Wenbo Shao,Jinlong Song 대한의학회 2014 Journal of Korean medical science Vol.29 No.11

Glutathione S-transferases (GSTs) are enzymes which play an important role in theneutralization of toxic compounds and eradication of electrophilic carcinogens. Geneticpolymorphisms within the genes encoding for GSTs may therefore cause variations in theirenzyme activity, which may in turn influence the interindividual susceptibility to cancers. In this study, we aimed to investigate the association between genetic polymorphisms ofGSTT1, GSTM1, and GSTP1 and the risk of colorectal cancer (CRC) in 264 cases and 317controls in a Chinese population. Genotyping was performed by using multiplex PCR (forGSTT1 and GSTM1) and PCR-RFLP (for GSTP1) methods. The association between thepolymorphic genotypes and CRC risk was evaluated by deriving odds ratios (ORs) and 95%confidence intervals (CIs) using unconditional logistic regression analysis. Our resultsshowed that individuals with GSTT1 and GSTM1 null genotypes exhibited a higher risk ofCRC (GSTT1, OR,1.66; 95% CI, 1.20-2.31, P = 0.003; GSTM1, OR,1.57; 95% CI,1.13-2.18, P = 0.007), while no association was observed for GSTP1 (Pheterozygous = 0.790 or Pvariant= 0.261). Furthermore, individuals who simultaneously carried the null genotypes forboth GSTT1 and GSTM1 showed a stronger risk association (OR, 1.95; 95% CI, 1.33-2.85;P < 0.001). In conclusion, the GSTT1 and GSTM1 polymorphisms, but not GSTP1, maymodulate the CRC risk among Chinese.

Fractional-Order Adaptive Sliding Mode Control for Fractional-Order Buck-Boost Converters

Xie Lingling,Liu Zhipei,Ning Kangzhi,Qin Rui 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.3

In previous studies, the combination of fractional calculus (FC) and sliding-mode control (SMC) has been gaining more and more interest due to fusion characteristics of SMC and FC. But most study integer-order buck converters, and few study control strategies of fractional-order converters. In this paper, the sliding mode controller and fractional adaptive sliding mode controller for fractional-order buck-boost converters are proposed. An affi ne nonlinear system model of the fractionalorder buck-boost converter is built. Based on the diff erential geometry theory, the exact feedback linearization is performed on the affi ne nonlinear model of the fractional-order buck-boost converter. On this basis, a fractional adaptive sliding mode controller is designed by selecting a linear sliding surface and adaptive control law. The stability of the fractional controller is proved by the Mittag–Leffl er stability theorem. The simulation results show that the fractional adaptive sliding mode control has good dynamic response performance and small steady-stage error regulating characteristics. Compared with traditional sliding mode control and PI λ control, the control method demonstrates stronger robustness under various disturbances.

Effects of Freeze and Cyclic Load on Impact Resistance of Filling Layer Self-Compacting Concrete (FLSCC)

Ning Li,Guangcheng Long,Qiang Fu,Cong Ma,Kunlin Ma,Youjun Xie 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.7

Filling layer self-compacting concrete (FLSCC) is a key material in newly-built China Rail Track System (CRTS), which is commonly subjected to cyclic dynamic load from high-speed train and various ambient temperature during service. In this paper, a series of indoor simulating experiments was conducted to investigate the impact resistance of FLSCC suffering from cyclic flexural load and different temperature conditions with a Φ75 mm split Hopkinson pressure bar (SHPB). The dynamic increase factors were introduced to evaluate the strain rate effect on various mechanical properties of FLSCC and the corresponding mechanisms were explained. Results show that the dynamic increase factor of compressive strength (DIFc) and peak strain (DIFε) of FLSCC increase linearly with logarithm of strain rate, while specific energy absorption increases exponentially with strain rate. The impact resistance of FLSCC is greatly influenced by cyclic flexural load and low temperature. The strain rate sensitivity of compressive strength of FLSCC at minus temperature (-20°C) is weaker than that at normal temperature (20°C) and after freeze-cyclic load coupling action the sensitivity decreases further. Similar tendencies were also observed in peak strain and specific energy absorption.

Performance differences of Rhode Island Red, Bashang Long-tail Chicken, and their reciprocal crossbreds under natural cold stress

Xie, Shanshan,Yang, Xukai,Gao, Yahui,Jiao, Wenjie,Li, Xinghua,Li, Yajie,Ning, Zhonghua Asian Australasian Association of Animal Productio 2017 Animal Bioscience Vol.30 No.10

Objective: The Bashang Long-tail chicken (BS), an indigenous Chinese breed, is considered cold tolerant. We selected BS, the Rhode Island Red (RIR), and their reciprocal crossbreds for the present study. The objectives were: i) to validate whether BS is cold tolerant and whether egg production and cold tolerance of crossbreds could be improved; and ii) to determine the physiological characteristics that underlie cold tolerance and favorable egg production performance in cold environments. Methods: A total of 916 chickens were reared in warm and natural cold environments (daily mean ambient temperature varied from $7.4^{\circ}C$ to $26.5^{\circ}C$ in the warm environment and from $-17.5^{\circ}C$ to $27.0^{\circ}C$ in the cold environment). To investigate their adaptability to the cold environment, the egg production performance and body weight were monitored and compared between breeds and environments. The cloacal temperature and serum biochemical parameters were monitored to reveal the physiological characteristics underlie cold tolerance and favorable egg production performance in the cold environment. Results: The warm environment experiment showed that RIR had the highest egg production performance, and that the reciprocal crossbreds had a higher egg production performance than BS. While in the cold environment RIR had the lowest egg production performance, and the reciprocal crossbreds had a higher egg production performance than BS. In the cold environment BS and reciprocal crossbreds had higher triiodothyronine, tetraiodothyronine levels than RIR. At 35 and 39 wk of age, when the ambient temperature was extremely low (varied from $-20^{\circ}C$ to $0^{\circ}C$), serum glucose, follicle-stimulating hormone, luteinizing hormone, estradiol of BS and crossbreds were higher than RIR. Conclusion: Bashang Long-tail chicken has a favorable cold tolerance ability. Crossbreeding with RIR and BS is an effective way to develop cold tolerant chickens with improved egg production performance.

The Detection of Osthole and Application of Cell Imaging Based on Nitrogen-Doped Carbon Dots

Ning Wang,Xuefang Yang,Haojiang Wang,Liping Xie,Weihua Jia,Wei Bian,Martin M. F. Choi 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2020 NANO Vol.15 No.03

A fluorescence probe has been synthesized for the detection of osthole using the nitrogen-doped carbon dots (NCDs) as shown in Fig. 1. The NCDs were fully characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR). Under the optimal experimental conditions, the NCDs fluorescence probe was highly selective and sensitive to osthole. The linear response range for osthole was 5.0–7 5μM with a detection limit of 38 nM. The mechanism of the interaction of osthole and NCDs was discussed. The fluorescence probe has been applied to the analysis of biological samples. The as-synthesized NCDs with high fluorescence intensity, low toxicity and good biocompatibility were applied to cell imaging.

High - Temperature Materials : THE STABILIZATION OF METASTABLE INTERMETALLIC PHASES IN INCONEL 718

Ning Wang,Xishan Xie,Andre Pineau,Soo Woo Nam 대한금속재료학회 ( 구 대한금속학회 ) 1995 Advanced Material and Processing Vol.3 No.-

Community detection based on BernNet graph convolutional neural network

Xie Hui,Ning Yixin 한국물리학회 2023 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.83 No.5

As an important part of network analysis, community detection has attracted extensive attention of researchers in various felds. Using Graph Neural Network (GNN) model to solve the problem of community detection is a new direction of community detection research. BernNet is a graph convolutional neural network based on Bernstein polynomial approximation of order K, which can be used to design arbitrary flters, but it is slow because of its quadratic dependence on K. In this paper, a novel algorithm using frst-order Bernstein polynomial is proposed: (i) approximate the defnition of flters, takes the original labels of data as the basis for community division; (ii) defnes the loss function between the labels predicted by the algorithm and the original data labels, (iii) acquires the probability model of node labels predicted by the node characteristic matrix with the smallest loss function through backpropagation. The results of community segmentation are evaluated using Normalized Mutual Information (NMI). Compared with the state-of-the-art methods, the experimental results show that: the algorithm can achieve better community detection results on real data sets and reduce the complexity of the algorithm while obtaining better results.

Nucleation Mechanism of Discontinuous Dynamic Recrystallization with Restrained Grain Boundary Sliding

Bingchao Xie,Baoyun Zhang,Hao Yu,Yongquan Ning 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.12

The discontinuous dynamic recrystallization (DDRX) nucleation process was investigated during the TMP of a nickel-basedsuperalloy with a coarse columnar-grain structure. Special attention was focused on the formation mechanism of the ‘newbornboundary’ which separates the free-strain volume from deformed grain. The special grain morphology and large grain sizerestrained the grain boundary sliding of the studied alloy, and hence made it difficult to form a subboundary through straininduction or twining to separate the free-strain volumes from the deformed grains. This is very different with the classicalDDRX theory, where the grain boundary sliding has less restraint and hence leads to grain boundary shearing and the followingstrain induced boundary or twin boundary. However, the experiment results showed that DDRX took place and developedwell during the studied deformation process with restrained grain boundary sliding. It was found that the ‘newborn boundary’,which separates the free-strain volume from deformed grain to close this area, was formed through dislocation piling-upand rearrangement instead of strain induction or twinning caused grain boundary shearing. Hence, a potential nucleationtheory was then proposed and discussed, which is expected to enrich the discontinuous dynamic recrystallization theory.

Low-Temperature Synthesis and Characterization of Ti2AlC/TiAl in situ Composites via a Reaction Hot-Pressing Process in the Ti3AlC2-Ti-Al System

Taotao Ai,Ning Yu,Xiaoming Feng,Niansuo Xie,Wenhu Li,Pengju Xia 대한금속·재료학회 2015 METALS AND MATERIALS International Vol.21 No.1

Ti2AlC/TiAl in situ composites were fabricated via a reaction Hot-Pressing Process using Ti3AlC2, Ti, and Alpowders as initial materials. The effect of Ti2AlC content on the phases and microstructure of the as-sinteredcomposites was investigated by XRD and SEM. The mechanical properties such as Vickers hardness, flexuralstrength and fracture toughness of the as-sintered composites were also tested. The products consisted ofTi2AlC, γ-TiAl and α2-Ti3Al as the major phases. Ti2AlC reinforcements were mainly distributed in the grainboundaries, resulting in obvious γ+α2 grain refinement. With increasing Ti3AlC2 content (up to 5 wt%), theVickers hardness, flexural strength and fracture toughness of the as-sintered composite reached the maximumvalues of 3.7 GPa, 651.5 MPa, and 10.89 MPa·m1/2, respectively. Analysis of fracture surface and crackpropagation paths indicated that crack deflection and crack bridging of the in situ precipitated Ti2AlC phasesobtained by decomposing Ti3AlC2 were the main reasons for the observed composite toughening.