Austenite Grain Growth Behavior of 30BF Steel Before Rough Rolling

Yong‑feng Chen,Jian‑bo Xie,Yan‑xin Wu,Jian‑xun Fu 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.4

To investigate the eff ect of heat treatment on the grain size of austenite in 30BF steel, the comparisons of the morphologiesand sizes of austenite grains between heating samples were made with a high-temperature electric resistance furnace, andthe austenite growth models were built with method of mathematics. The results show that most grains in original specimenwith the sizes below 70 μm uniformly distributed. At a heating rate ( v ) of 10 °C/s, the grain size ( d ) value under a certain time( t ) increased by 60–100 μm with raising temperature ( T ) from 850 to 1100 °C, whereas the d value under a certain T merelyincreased by 70–120 μm with raising time to 60 min. Under v = 0.1 °C/s, T = 850 °C, and t = 0 s, the occupied ratio of grainswith sizes of 40–50 μm was 0.165, whereas at 900 °C, the occupied ratio was 0.125. The evolutions of ln (d5.8− d5.80 ) with1/ T were in negative linear correlations, whereas the ln (d5.8− d5.80 ) with ln t were in positive linear correlations. To sum up,the grain growth behavior of steel was elucidated.

마그네슘 풍부 해양미네랄 용액이 hairless 마우스의 아토피성 피부염에 미치는 영향

김동희,이규재,최주봉,이영미,윤양숙,김정례,장병수,양용석 韓國電子顯微鏡學會 2008 Applied microscopy Vol.38 No.3

Atopic dermatitis (AD) is a chronically relapsing inflammatory skin disease that often has asthma and allergic rhinitis. Magnesium salts, the important component of minerals in Dead Sea water, are known to exhibit beneficial effects in inflammatory disease. Favorable effects of magnesium ions and sea water treated to the skin of patients with contact dermatitis have been reported. But histological and immunological investigations are insufficient. This study was performed to examine the inhibitory effect of magnesium-rich sea mineral water on the development of AD-like skin lesions in hairless mice. AD-like skin lesions are induced by the repeated application of 2,4-dinitrochlorobenzene (DNCB). Local application of magnesium-rich sea mineral water on hairless mice skin applied with DNCB inhibited the development of AD-like skin lesions as exemplified by a significant increase in skin hydration (p<0.01), and a decrease in epidermal water loss (p<0.01). Serum IgE level was also significantly decreased (p<0.01). These results suggest that magnesiumrich sea mineral water inhibits the development of DNCB-induced AD-like skin lesions in hairless mice. These observations indicate that magnesium-rich sea mineral water may be alternative and assistant substances for the management of AD. 아토피성 피부염은 주로 천식과 비염 등을 동반하는, 주위에서 흔히 볼 수 있는 만성 염증성 피부질환으로 유전학적, 환경적, 면역학적 요인이 복잡하게 연관되어 발병한다. 해수에 포함된 마그네슘염은 피부에 작용하여 피부장벽을 보호하는 것으로 알려지고 그에 대한 면역학적인 연구와 조직학적 연구는 아직 부족한 실정이다. 이번 연구에서는 피부염을 인위적으로 일으키는 hapten 형성물질인 DNCB를 hairless mice에 도포하여 아토피 피부염 동물 모델로 만든 후, 마그네슘이 다량 함유된 해양 미네랄수를 처리한 후 피부장벽에 미치는 영향을 관찰하였다. DNCB로 피부염을 유발한 hairless mice에 해양미네랄수를 국소적으로 도포하였을 때 유의한 피부수분함량이 증가와 경피수분손실의 감소를 확인하였다 (p<0.01). 피부측정에서 피부거칠기(skin roughness, p<0.05)와 스케일생성 (skin scaliness, p<0.01)은 실험군에서 유의한 개선효과를 나타내었으며 조직학적 검사에서도 피부손상지수의 유의한 감소 (p<0.01)와 비만세포와 (p<0.01) 호산구의 감소(p<0.05) 소견을 보였고 또한 혈청 IgE의 감소를 관찰할 수 있었다(p<0.01). 이상과 같이 마그네슘이 다량 함유된 해양 미네랄수 도포는 피부장벽의 손상을 줄이고 피부수분손실을 효과적으로 줄임으로 아토피성 피부염 증상 유발을 억제할수 있음을 확인하였다. 현재까지 아토피성 피부염의 관리를 위하여 세라마이드나 식물성 오일의 보습제가 주로 활용되고 있는 상황에서 부가적인 피부장벽의 보호를 위하여 탈염 해양 미네랄수의 활용이 가능할 것으로 판단되며 장기적으로 아토피 피부염치료의 대체, 혹은 보조적 물질로 활용될 수 있을 것으로 기대된다.

Research on Factors influencing Physical Education Major Students in Choosing Sport Specialties at South China Universities

( Yong Feng Xu ) 한국체육학회 2015 국제스포츠과학 학술대회 Vol.2015 No.1

Purpose: This paper is intended to understand the factors that influence the choice of different specialties by Physical Education major students in South China universities. Addition to it, the paper hopes to provide reference for adjustment in the enrollment system, training objectives, curriculum at different levels of sports training institution. Meanwhile, it could facilitate specialty development of students, co-ordinate basic and specialized courses, adjust the proportion of different level courses. In the end, it could provide reference to understand the differences that appear at the learning process of student. Method: The author has accessed a large selection of special physical education major relevant documents and information, read the relevant books and papers, which laid a theoretical foundation for this paper. A survey was conducted mainly targeting sophomores and juniors majoring in Physical Education at 6 higher institutes of south China. A total of 360 questionnaires were sent and 356 were taken back , with a recovery rate of 98.9%, among which were 354 valid questionnaires, with the effective rate of 99.4%. The author used Excel, Access and other self-built database to process the data collected from the survey. Result: Different sports have different requirement so teachers will evaluate whether students`` abilities are consistent with the that sport by specific task. Through the investigation of PE major, the author discovers that hobbies, gender, physical fitness, and influences from others will have impact on students`` choice of their sport specialties. Hobby is the primary factor, followed by personal fitness ,gender. Charisma and teaching ability of teacher also play an important role. In the end, family economic situation could affect students`` choice. Conclusion: In all, subjective reason is the factor contributing to the choice of students. 56.37% of students make their choice of specialty based on their interests. However, there are some students choosing their specialty according to the need of future job market. Most of the students can realize the importance of the choice of specialty. When they face difficulties, they can actively seek help from senior students. In the end, the school curriculum setting and the school facility can largely affect students`` choice of their specialties.

Convergence properties of partial sums for arrays of rowwise negatively orthant dependent random variables

Yong-Feng Wu,Dong-jin Zhu 한국통계학회 2010 Journal of the Korean Statistical Society Vol.39 No.2

Let {Xnk,1 ≤ k ≤ n, n ≥ 1} be an array of rowwise negatively orthant dependent random variables and let fan; n ≥ 1g be a sequence of positive real numbers with an ↑∞. The convergence properties of partial sums 1an Pn k D1 Xnk are investigated and some new results are obtained. The results extend and improve the corresponding theorems of rowwise independent random variable arrays by Hu and Taylor [Hu, T. C., Taylor R. L. (1997). On the strong law for arrays and for the bootstrap mean and variance. International Journal of Mathematics and Mathematical Sciences, 20(2), 375382].

DESIGN AND CONTROL OF A GRINDING ROBOT

Yong, Feng,Guo, Xu Dian,Yan, Wang 대한전자공학회 1992 HICEC:Harbin International Conference on Electroni Vol.1 No.1

This paper describes a grinding robot: HITDM-I, which is the fast grinding robot in our country. The grinding robot adopts teach-repeat operating mode. This paper mainly describes control system of the grinding robot, including the hardware and software.

Selective Oxidation of Alloys on the Surface of TRIP Steel During Annealing (초)

( Yong Feng Gong ),김한수,( B. C. De Cooman ) 대한금속재료학회 ( 구 대한금속학회 ) 2007 대한금속재료학회 학술대회 개요집 Vol.2007 No.1

A study on genotypic variations of Pb accumulation and distribution among organs of rice plant

Yong-Feng Yan,Doug-Hwan Choi,Jin-Ern Lee,Byun-Woo Lee 한국작물학회 2008 한국작물학회 학술발표대회 논문집 Vol.2008 No.10

In order to investigate the genotypic differences in Pb accumulation of rice, thirty-five rice cultivars were irrigated by irrigation water containing 10 ppm Pb throughout all growth season under field condition. At harvest, thirty-five rice cultivars showed significant difference in Pb concentrations in straw, grain, chaff, brown rice, rice bran, and polished rice, but not in root. Pb concentration in polished rice ranged from 0.02 to 0.22 mg/kg. The total Pb accumulation in shoot varied from 0.77 to 2.74 mg/m2. There were no significant difference of Pb concentration in all of rice parts among four rice cultivar groups. Indica and tongil cultivar groups presented the higher Pb accumulation in shoot. The large genotypic variation suggested the possibility of breeding low Pb accumulating rice cultivar.

Site-directed Mutagenesis of the Toxin from the Chinese Scorpion Buthus martensii Karsch (BmKAS): Insight into Sites Related to Analgesic Activity

Yong Cui,Yong-Bo Song,Lin Ma,Yan-Feng Liu,Guo-Dong Li,Chun-Fu Wu,Jing-Hai Zhang 대한약학회 2010 Archives of Pharmacal Research Vol.33 No.10

This study utilized the E. coli expression system to investigate the role of amino acid residues in toxin from the Chinese scorpion - Buthus martensii Karsch (BmKAS). To evaluate the extent to which residues of the toxin core contribute to its analgesic activity, ten mutants of BmKAS were obtained by PCR. Using site-directed mutagenesis, all of these residues were substituted with different amino acids. This study represents a thorough mapping and elucidation of the epitopes that form the molecular basis of the toxin’s analgesic activity. Our results showed large mutant-dependent differences that emphasize the important roles of the studied residues.

Simulation on the Supporting of Underground Storage Foundation Pit by Anchor and Soil Nail

Yong Feng 보안공학연구지원센터 2015 International Journal of Smart Home Vol.9 No.6

Transcriptome profiling of Shindongjin and Sugary mutant at grain-filling stages using RNA-Seq

Feng-Peng Li,Min-Young Yoon,Gang Li,Yong-Jin Park 한국육종학회 2013 한국육종학회 심포지엄 Vol.2013 No.07

Rice (Oryza sativa) is an excellent model monocot with a known genome sequence for studying developmental seeds. In the study, the seeds of 10th day after flowering (DAF) were conducted RNA-Seq of the variety Shindongjin and Sugary mutant using RNA-seq technique. Approximately 202 and 214 million high-quality paired-end reads (101-bp in size) were generated in Shindongjin and Sugary mutant, respectively. Comprehensive analysis on the transcript levels of genes which encode starch-synthesis enzymes is fundamental for the assessment of the function of each enzyme and the regulatory mechanism of starch biosynthesis in seeds. Quantitative real-time PCR was also used to validate the expression profiles of 28 rice genes encoding six classes of enzymes, viz., ADPglucose pyrophosphorylase (AGPase), starch synthase, starch branching enzyme, starch debranching enzyme, starch phosphorylase, and disproportionating enzyme at different developmental grain- filling stages (DAF 1-14) between Shindongjin and Sugary mutant. The results showed that the expression of most of starch synthesis genes were up-regulated except the cytosolic AGPase small subunit2b (AGPS2b), which sharply decreased at grain-filling stages in Sugary mutant. These results will expand our understanding of the complex molecular and cellular events in rice grain-filling stages and provide a fundamental understanding of future studies on developmental endosperm in rice and other cereal crops.