Numerical optimization of transmission bremsstrahlung target for intense pulsed electron beam

Xiao Yu,Jie Shen,Shijian Zhang,Jie Zhang,Nan Zhang,Ivan Sergeevich Egorov,Sha Yan,Chang Tan,Gennady Efimovich Remnev,Xiaoyun Le 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.2

The optimization of a transmission type bremsstrahlung conversion target was carried out with MonteCarlo code FLUKA for intense pulsed electron beams with electron energy of several hundred keV formaximum photon fluence. The photon emission intensity from electrons with energy ranging from300 keV to 1 MeV on tungsten, tantalum and molybdenum targets was calculated with varied targetthicknesses. The research revealed that higher target material element number and electron energy leadsto increased photon fluence. For a certain target material, the target thickness with maximum photonemission fluence exhibits a linear relationship with the electron energy. With certain electron energy andtarget material, the thickness of the target plays a dominant role in increasing the transmission photonintensity, with small target thickness the photon flux is largely restricted by low energy loss of electronsfor photon generation while thick targets may impose extra absorption for the generated photons. Thespatial distribution of bremsstrahlung photon density was analyzed and the optimal target thicknessesfor maximum bremsstrahlung photon fluence were derived versus electron energy on three targetmaterials for a quick determination of optimal target design

Analysis on the Present Situation of Golf Vocational Training in China

Xiaoyu Zhang(Xiaoyu Zhang),Junhee Hong(Junhee Hong) 동아시아무역학회 2022 Journal of East Asian Trade(JEAT) Vol.4 No.1

Purpose – Golf started on September 30th, 1982, when Zhang Junlin registered and established Shenzhen Golf Club Co., Ltd. in Shenzhen Municipal Market Supervision Administration. In September of the same year, it was approved by Shenzhen Municipal People’s Government. The establishment of the first established golf club in China also marks the official entry of modern golf into the Chinese market. In 1997, Shenzhen University established the first golf major in China, and now there are nearly 600 golf courses in China. China’s golf industry is still developing at a high speed despite policy restrictions. However, there are still some deficiencies in golf vocational training in China. Through the analysis of the shortcomings, the reasonable development direction is put forward. Design/Methodology/Approach – With the development of golf industry, supporting education has also been carried out in China. Since Shenzhen University, many colleges and universities have also carried out related majors. Golf industry is not limited to golf, but also includes lawn planting, garden art, fashion design, sporting goods manufacturing, hotel management, real estate development, golf education and training, etc., which makes the golf industry bring a variety of jobs and personnel needs. It also makes golf clubs pay more attention to talent cultivation. In this paper, the problems existing in the training of golf talents in clubs and universities are listed and analyzed by means of investigation, to find out the appropriate direction. Findings – Children are an important member of golf club staff. How to carry out good caddy training and improve caddy’s professional level and comprehensive quality has become the task focus of golf club managers. At present, the common problems of golf caddies in China are: 1. There is no uniform training standard, which makes the quality of caddies uneven. 2. The income of caddies is unstable. 3. Most of the temporary employment relationships between caddies and clubs. 4. Caddy talent reserve can’t meet the needs of club staff. 5. Caddy occupation requires physical condition, and it is difficult to transform after unemployment. Research Implications – A good teaching foundation is an important way to cultivate talents, and only the mutual communication between clubs and colleges can help improve the ability of golf vocational training in China.

A novel synthesis of hexagonal cylinder-like ZnO with an excellent performance by a surfactant-free microemulsion-hydrothermal method

Xiaoyu Zhang,Ying Han,Wenjiao Liu,Ning Pan,Dejie Li,Jinling Chai 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.97 No.-

A W/O surfactant-free microemulsion (SFME) template-hydrothermal method for the preparation of ZnOproducts was proposed. Using the SFME system containing hexane, propan-2-ol and water, hexagonalcylinder-like (twinning) ZnO microcrystals were synthesized. The XRD, SEM and TEM characterizationsshowed that the synthesized ZnO microcrystals have a hexagonal wurtzite structure. At hydrothermaltemperatures of 120–140 C, hexagonal cylinder-like ZnO microcrystals were synthesized, whereas thehexagonal cylinder twinning ZnO microcrystals were obtained at 160 C. The growth mechanism of theZnO microcrystals was also investigated. The EPR and XPS spectra of the synthesized ZnO products showed that there are oxygen vacancies onthe ZnO surface. The photodegradation behavior of methylene blue (MB, 10 ppm) with a UV-Hg lamp(250 W) as the light source in ZnO aqueous suspension (0.3 g L 1) was investigated. The ZnO productsynthesized at 140 ℃ can significantly photocatalyze the degradation of lower concentration MBsolutions. After 35 min of irradiation, the photocatalytic decomposition rate reached 98.3%. It is hopedthat this work could serve as an important stepping stone for establishing a novel hydrothermal methodbased on SFME system, therefore paving the way for other potential ideas on the application of SFMEsystems.

Feedback control for a turbidostat model with ratio-dependent growth rate

Xiaoyu Hu,Zuxiong Li,Xingguo Xiang 한국전산응용수학회 2013 Journal of applied mathematics & informatics Vol.31 No.3

In this paper, a turbidostat model with ratio-dependent growth rate and impulsive state feedback control is considered. We obtain sufficient conditions of the globally asymptotically stable of the system without impulsive state feedback control. We also obtain that the system with impulsive state feedback control has periodic solution of order one. Sufficient conditions for existence and stability of periodic solution of order one are given. In some cases, it is possible that the system exists periodic solution of order two. Our results show that the control measure is effective and reliable.

EFFECT OF THIOPHENE IN BITHIAZOLE-BRIDGED SENSITIZERS ON THE PERFORMANCE OF DYE-SENSITIZED SOLAR CELLS

XIAOYU ZHANG,JIANLI HUA,JINXIANG HE,WENJUN WU,HANS AGREN,XIN LI,FULING GUO 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2014 NANO Vol.9 No.5

In this paper, we have designed and synthesized four bithiazole-bridged sensitizers (BT-T2,TBT-T2, BT-T3 and TBT-T3) with triphenylamine and indoline as the donor segment andapplied them to dye-sensitized solar cells (DSSCs). For triphenylamine-based sensitizers as BT-T2 and TBT-T2, adding one thiophene unit between triphenylamine donor and bithiazolemoiety not only led to bathochromic shift of the maximum absorption and increase of molarextinction coe±cient, but also enhanced the photovoltaic conversion e±ciency from 7.12% ofBT-T2 to 7.51% of TBT-T2. But for indoline-based sensitizers as BT-T3 and TBT-T3,adding one thiophene unit between indoline donor and bithiazole moiety resulted in hypochro-matic shift instead of bathochromic shift. We employed the density functional theory (DFT)calculations to further investigate the in°uence of the thiophene unit on their optical and elec-tronic properties and photovoltaic performance of corresponding DSSC devices. Given theresults, a reasonable explanation is the introduction of thiophene unit suppressed the intramo-lecular charge transfer and charge separation in the conjugation system of indoline-based sen-sitizer, which led to the hypochromatic shift of the maximum absorption wavelength and ¯nallythe low Jsc . Since the Jsc dropped sharply from 15.26 mAcm? 2 to 4.52 mAcm? 2 , the photovoltaicconversion e±ciency decreased dramatically from 7.86% to 1.93%.

Detecting Active Brain Regions by a Constrained Alternating Least Squares Nonnegative Matrix Factorization Algorithm from Single Subject’s fMRI Data

Xiaoyu Ding,Jong-Hwan Lee(이종환),Seong-Whan Lee(이성환) 한국정보과학회 2011 한국정보과학회 학술발표논문집 Vol.38 No.1C

In this paper, we propose a constrained alternating least squares nonnegative matrix factorization algorithm (cALSNMF) to detect active brain regions from single subject's task-related fMRI data. In cALSNMF, we define a new cost function which considers the uncorrelation and noisy problems of fMRI data by adding decorrelation and smoothing constraints in original Euclidean distance cost function. We also generate a novel training procedure by modifying the update rules and combining with optimal brain surgeon (OBS) algorithm. The experimental results on visuomotor task fMRI data show that our cALSNMF fits fMRI data better than original ALSNMF in detecting task-related brain activation from single subject’s fMRI data.

Implementation of a Particle Swarm Optimization-based Classification Algorithm for Analyzing DNA Chip Data

Xiaoyue Han,이민수 한국유전체학회 2011 Genomics & informatics Vol.9 No.3

DNA chips are used for experiments on genes and provide useful information that could be further analyzed. Using the data extracted from the DNA chips to find useful patterns or information has become a very important issue. In this paper, we explain the application developed for classifying DNA chip data using a classification method based on the Particle Swarm Optimization (PSO) algorithm. Considering that DNA chip data is extremely large and has a fuzzy characteristic, an algorithm that imitates the ecosystem such as the PSO algorithm is suitable to be used for analyzing such data. The application enables researchers to customize the PSO algorithm parameters and see detail results of the classification rules.

A Clustering Tool Using Particle Swarm Optimization for DNA Chip Data

Xiaoyue Han,이민수 한국유전체학회 2011 Genomics & informatics Vol.9 No.2

DNA chips are becoming increasingly popular as a convenient way to perform vast amounts of experiments related to genes on a single chip. And the importance of analyzing the data that is provided by such DNA chips is becoming significant. A very important analysis on DNA chip data would be clustering genes to identify gene groups which have similar properties such as cancer. Clustering data for DNA chips usually deal with a large search space and has a very fuzzy characteristic. The Particle Swarm Optimization algorithm which was recently proposed is a very good candidate to solve such problems. In this paper, we propose a clustering mechanism that is based on the Particle Swarm Optimization algorithm. Our experiments show that the PSO-based clustering algorithm developed is efficient in terms of execution time for clustering DNA chip data, and thus be used to extract valuable information such as cancer related genes from DNA chip data with high cluster accuracy and in a timely manner.

MECHANOCHEMICAL SYNTHESIS OF NiO NANOPARTICLES: INSIGHT INTO THE NATURE OF PREFERRED GROWTH ORIENTATION

XIAOYU LI,HUAMING YANG,LIANGJIE FU,TIANCHENG LIU 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2014 NANO Vol.9 No.4

Nickel oxide (NiO) nanoparticles were synthesized by calcination at 400?C to 700?C for 8 h of theprecursor obtained via mechanochemical reaction of Ni(NO 3 ) 2 ? 6 H 2 O with citric acid as a dis-persant. The nanoparticles were characterized by thermogravimetric-diferential scanningcalorimetry (TG-DSC), X-ray difraction (XRD) and transmission electron microscopy (TEM). The kinetics of diferent surfaces of the nanocrystals under nonisothermal conditions wasinvestigated. The activation energies for diferent lattice planes of NiO nanoparticles weredetermined using the Arrhenius equation, revealing their preferred orientation. The growth ofNiO obeyed the general theory that nanoparticles with the largest surface energy tend to form. XRD data reveal that the NiO nanoparticles possess preferred (111) or (200) orientations thatre°ect their complex activity. The nature of preferred growth orientation was found to benegative difusion activity among diferent lattice surfaces, which indicates that oxygen atomsdi®use from low oxygen concentration on the lattice surface to high concentration on the latticesurface.

Continuous Sliding Mode Tracking Control with Robust Observer for Nonlinear Systems with Control Gain Uncertainty

Xiaoyu Zhang 보안공학연구지원센터 2014 International Journal of Control and Automation Vol.7 No.5