A multi-factor comprehensive optimization of a supercritical carbon dioxide radial inflow turbine with low specific speed

Jinxing Li,Dongbo Shi,Guangya Zhu,Yonghui Xie 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.10

An integrated method combining one-dimensional design and automatic threedimensional optimization is proposed for SCO 2 radial inflow turbines with low specific speed. The optimization of the nozzle and impeller are performed simultaneously. Four optimization algorithms, namely, grey wolf optimizer, elephant herding optimization, genetic algorithm, and simulated annealing algorithm, are integrated with computational fluid dynamics simulation and finite element analysis to improve the turbine efficiency. Two constraints (mass flow variation and maximum stress) are imposed in the optimization process. The results indicate that the grey wolf optimizer is the optimal algorithm. The total-to-static efficiency of the optimal turbine is 89.56 %, which is increased by 3.25 %. Moreover, splitter blades are also investigated and optimized. The maximum total-to-static efficiency of 90.16 % can be obtained by reasonably arranging splitter blades. The proposed method is versatile, nimble, and easy to implement. It can improve the design efficiency and provide a geometric reference for low specific speed SCO 2 turbines.

Discrete Hopfield Neural Networks for Evaluating Service Quality of Public Transit

Jinxing Shen,Wenquan Li 보안공학연구지원센터 2014 International Journal of Multimedia and Ubiquitous Vol.9 No.2

Multi-Modal Stress Characteristics Under Coupling Effect of Strip and Work Roll

Jinxing Cui,Yan Peng,Jianliang Sun,Boyang Li 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.22 No.10

In this paper, we investigate the rolling interface instability characteristics caused by the coupled motion of strip and the roll system. Based on the experimental test, the dynamical behaviors of the rolling mill under the motion of roll system and the strip show multi-modal vibration phenomenon, which are consistent with the variation of rolling interface force and energy parameters. Then, the dynamic geometric parameters of rolling interface and the dynamic stress models are established. Through the simulation analysis, it can be concluded the multi-modal stress state of the rolling interface is caused by the coupling motion of the strip and the roll system. The results show that the multi-modal stress of the rolling interface cause the rolling process instability, leading the "pulling " on the strip and "beating" on the work roll, which change the instability state of the rolling process. This study provides a theoretical basis for the study of multi-modal vibration characteristics of rolling mill.

Tunneling Enhanced Structure for Improving the Performance of Ultraviolet Light-emitting Diodes

Jinxing Wu,Peixian Li,Xiaowei Zhou 대한전자공학회 2020 Journal of semiconductor technology and science Vol.20 No.6

The novel AlGaN-based ultraviolet light-emitting diode (UV-LED) with a tunneling enhancement structure is proposed. The tunneling enhanced structure consists of an ITO layer, an extremely thin AlN layer, and a p+-GaN layer. Under forward bias, compared to traditional devices, tunneling enhanced UV-LEDs can shorten the width of the tunneling region. In addition, the dielectric constant of the AlN layer in the tunnel area is small, which can effectively increase the transport of holes from the ITO layer to the MQWs active region. Due to the increased hole concentration and drift speed, for a 300 ㎛ × 254 ㎛ UV-LED chip, the optical output power increased by 19.6% at 120 ㎃. Therefore, the proposed tunneling enhanced structure provides a simple and effective way to increase the light output power of UV-LEDs.

Preparation, characterization, and properties of novel meglumine-based polysiloxane surfactants

Yanyun Bai,Jinxing Li,Xiumei Tai,Guoyong Wang 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.84 No.-

A series of meglumine-based polysiloxane surfactants, (PSim-n) with different numbers of megluminebranches were prepared. The formed surfactants were characterized by FT-IR and NMR techniques. Physiochemical properties, such as surface activity, aggregation behavior, and wettability, were closelyexamined and used to differentiate the various samples. Thefindings demonstrate that PSim-n surfactantspossess high surface activity and can wet-out a parafilm surface at all but extremely low concentrations. Furthermore, PSi6-4, the surfactant with the highest meglumine concentration, can form larger complexaggregates in aqueous solutions.

Evaluation of the effect of mechanical deformation on beam isocenter properties of the SC200 scanning beam delivery system

Wang, Ming,Zheng, Jinxing,Song, Yuntao,Li, Ming,Zeng, Xianhu Korean Nuclear Society 2020 Nuclear Engineering and Technology Vol.52 No.9

For proton pencil beam scanning (PBS) technology, the accuracy of the dose distribution in a patient is sensitive to the properties of the incident beam. However, mechanical deformation of the proton therapy facility may occur, and this could be an important factor affecting the proton dose distribution in patients. In this paper, we investigated the effect of deformation on an SC200 proton facility's beam isocenter properties. First, mechanical deformation of the PBS nozzle, L-shape plate, and gantry were simulated using a Finite Element code, ANSYS. Then, the impact of the mechanical deformation on the beam's isocenter properties was evaluated using empirical formulas. In addition, we considered the simplest case that could affect the properties of the incident beam (i.e. if only the bending magnet (BG3) has an error in its mounting alignment), and the effect of the beam optics offset on the isocenter characteristics was evaluated. The results showed that the deformation of the beam position in the X and Y direction was less than 0.27 mm, which meets the structural design requirements. Compared to the mechanical deformation of the L-shape plate, the deformation of the gantry had more influence on the beam's isocenter properties. When the error in the mounting alignment of the BG3 is equal to or more than 0.3 mm, the beam deformation at the isocenter exceeds the maximum accepted deformation limits. Generally speaking, for the current design of the SC200 scanning beam delivery system, the effects of mechanical deformation meet the maximum accepted beam deformation limits. In order to further study the effect of the incident beam optics on the isocenter properties, a fine-scale Monte Carlo model including factors relating to the PBS nozzle and the BG3 should be developed in future research.

Comparative transcript profiling and cytological observation of the newly bred recessive genic male sterility non‑heading Chinese cabbage (Brassica rapa ssp. chinensis) line WS24‑3A

Liping Song,Xia Li,Feng Zu,Changbin Gao,Bincai Wang,Chufa Lin,Jinxing Tu,Aihua Wang,Guolin Zhou 한국유전학회 2019 Genes & Genomics Vol.41 No.12

Background WS24-3A is a newly bred non-heading Chinese cabbage genic male-sterile line, in which sterility is controlled by a recessive gene, designated as Bra2ms. WS24-3A has been used for hybrid breeding. Objective To reveal the underlying molecular mechanisms responsible for the sterility of WS24-3A. Methods Cytological observation of the process of sterile/fertile anther development was performed to determine the tissue and stage in which sterility occurs. Phenotyping and transcriptomic analyses were performed to identify differentially expressed genes (DEGs) between sterile and fertile flower buds at different stages. Results Cytological analysis revealed no tetrads at stage 7 or at later stages of anther development, and the degradation of callose was delayed. Abnormal meiocytes were surrounded by sustaining callose that degenerated gradually in WS24-3A. Comparative transcript profiling identified 3282 DEGs during three anther developmental stages, namely, pre-meiotic anther, meiotic anther, and anthers with single-celled pollen stage. The difference in DEG percentage between up-regulated and down-regulated at meiotic anther stage was obviously larger than at the other two stages; further, most DEGs are important for male meiosis, callose synthesis and dissolution, and tapetum development. Ten DEGs were found to be involved in anther and pollen development, which were analyzed by quantitative PCR. Conclusion Bra2ms affected gene expression in meiocytes and associated with callose synthesis, degradation and tapetum development. Our results provide clues to elucidate the molecular mechanism of genic male sterility in non-heading Chinese cabbage.

Identification of a nuclear-recessive gene locus for male sterility on A2 chromosome using the Brassica 60 K SNP array in nonheading Chinese cabbage

Guolin Zhou,Xia Li,Aihua Wang,Feng Zu,Zhenhua Hu,Jiazao Lin,Jinxing Tu 한국유전학회 2016 Genes & Genomics Vol.38 No.12

WS24-3 is a newly bred recessive genic male sterility line of the non-heading Chinese cabbage (Brassica rapa ssp. chinensis). Here, an F2 population was produced from the cross between WS24-3 and a male-fertile breeding line (WS135). The Illumina Brassica 60 K single nucleotide polymorphism (SNP) array was used for SNPs detecting between sterile and fertile bulks from the F2 population, and 62 SNPs were identified. BLAST analysis of the 62 SNPs revealed that the A2 chromosome of Brassica rapa genome contained 22 SNPs, whereas the other chromosomes did not contain more than 6 SNPs each. These data indicated that the potential target gene locus, named Bra2Ms, might be located on A2. Based on 10 of the 22 SNPs, allele-specific-polymerase chain reaction (AS-PCR) primers and single sequence repeat (SSR) primers were designed, 5 AS-PCR primers and 9 SSR primers showed difference between the bulks in electrophoretic determination. Analysis of these markers in F2 population revealed that Bra2Ms was genetically delimited to a region of 1.2 cM. We also detected two co-segregated markers SSRa2-951 and SSRa2-960 in this region. The markers identified in our study might facilitate the transfer of recessive genic male sterility alleles to other favorable genetic backgrounds. Furthermore, these markers will support a map-based clone of Bra2Ms.

DHEM: a deep heat energy method for steady-state heat conduction problems

Huanhuan Gao,Wenjie Zuo,Zengming Feng,Jinxing Yang,Tingting Li,Ping Hu 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.11

Based on the deep energy method recently brought forward to handle linearelastic or hyper-elastic finite deformation problems in solid mechanics, in this paper, we propose a deep heat energy method (DHEM) which is specially tailored to deal with structural steady-state heat conduction problems with the help of deep learning techniques. In our work, the deep neural networks are utilized to construct the admissible temperature fields; secondly, the potential energy functional in the heat conduction process which works as the loss function of the deep neural networks is calculated by numerical integration techniques; finally, the parameters of the network including weights and bias, are optimized by the quasi-Newton method to yield the minimal of the potential energy functional which indicates the heat conduction has entered a steady state. Numerical examples with a diversity of materials, including the isotropic and homogeneous material, the orthotropic material, the non-homogeneous materials and temperature dependent materials, are carried out to illustrate the validity and capacity of DHEM in both linear uncoupled and thermal-material coupling heat conduction problems.

Investigating the effects of a range shifter on skin dose in proton therapy

Wang Ming,Zhang Lei,Zheng Jinxing,Li Guodong,Dai Wei,Dong Lang 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.1

Proton treatment may deliver a larger dose to a patient’s skin than traditional photon therapy, especially when a range shifter (RS) is inserted in the beam path. This study investigated the effects of an RS on skin dose while considering RS with different thicknesses, airgaps and materials. First, the physical model of the scanning nozzle with RS was established in the TOol for PArticle Simulation (TOPAS) code, and the effects of the RS on the skin dose were studied. Second, the variations in the skin dose and isocenter beam size were examined by reducing the air gap. Finally, the effects of different RS materials, such as polymethylmethacrylate (PMMA), Lexan, polyethylene and polystyrene, on the skin dose were analysed. The results demonstrated that the current RS design had a negligible effect on the skin dose, whereas the RS significantly impacted the isocenter beam size. The skin dose was increased considerably when the RS was placed close to the phantom. Moreover, the magnitude of the increase was related to the thickness of the inserted RS. Meanwhile, the results also revealed that the secondary proton primarily contributed to the increased skin dose.