Intragranular and Intergranular Crack Propagation in Nanocrystalline Ni Under Single-Cycle Mode I Loading

Yan Feng,Jie Li,Xinhua Yang 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.7

As the first step to study the fatigue crack propagation, the molecular simulations were performed to investigate theopening, propagation and closure behaviors of intragranular and intergranular cracks in nanocrystalline Ni under single-cyclemode I loading. The atomic crack angle was proposed to characterize the crack-tip blunting and sharpening quantitatively. There are obvious different mechanisms between intragranular and intergranular crack propagation. Intragranular crack propagationcould be induced by stacking faults and can change its direction very easily, but the intergranular crack perpendicularto the loading direction would propagate along the grain boundary and encounter strong resistance at the triple junction. New cracks could form in the grain boundaries ahead of the original crack. Different from the traditional understanding forintragranular and intergranular cracks, however, the dislocation density increases even in the unloading process and the cracktip is possibly sharpened temporarily during loading.

Effect of Al on the Microstructure and Mechanical Properties of Mg–Sn–Ca–Mn Wrought Alloy

Yun Feng,Yuanyuan Yang,Zongqi Xiao,Xianglong Meng,Guorong Zhou,Jinfeng Leng,Xinying Teng 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.6

Mg–Sn–Ca–Mn–xAl (x = 0,1.5 wt%) alloys with ultra-fine recrystallized grains were prepared by conventional extrusion(400 °C, 0.5 mm/s). Effects of aluminum (Al) on mechanical properties and microstructure of the Mg–1Sn–1Ca–0.5Mn(wt%) alloy were systematically investigated. By the addition of 1.5 wt% Al, the yield strength of the as-extruded alloysignificantly increased from 183 to 237 MPa. The as-cast alloys show a dendritic structure consists of α-Mg, (Mg, Al)2Ca,and CaMgSn phases. The as-extruded Mg–1Sn–1Ca–0.5Mn–1.5Al alloys exhibit a bimodal grain structure composed ofdynamic recrystallized (DRXed) fine grains and coarse unDRXed grains. Compared with Al free alloy, a lot of nano-scaleplanar Al2Caand rectangle shape Al8Mn5precipitated in the as-extruded alloy with 1.5 wt% Al. Meanwhile, the addition ofAl significantly strengthened alloys’ fiber texture with < 10–10 >//ED.

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.

孔子的“中庸”智慧

???(Yang Feng-Gang) 동아인문학회 2008 동아인문학 Vol.14 No.-

"The doctrine of the mean"as the basic ideas and concepts of the Confucianism, has had a long-time and the profound influence to the Chinese cultural development, meanwhile, it also has played an important role to shape the culture of psychological structure and way of life of the Chinese people. It can be said that "the doctrine of the mean"has become a unique characteristics of the Chinese culture. However, the wisdom have suffered all sorts "the hypocrite"and the vulgarized misregistration and misinterpret for a long time. Especially in the present time, to many people, "the doctrine of the mean" have been understood and criticized as the attitude towards the smooth sophistication and ambiguity, the rules of life skills. In this context, "the doctrine of the mean"has completely lost its original connotation of the spirit. This article attempts to interpret and study its real meaning of "the doctrine of the mean" in Confucius’s context and in the Chinese thought's intrinsic sight races. Through studying and explanation to the related documents, this article think that "the doctrine of the mean"idea is a kind of political ideals in ancient civilization period, it is expressed, established and formed in the political realm and through political expression in the most early time. Confucius summarized and has inherited this ideological tradition and its thinking resources, and has developed its connotation greatly in the value standard position, has opened a brand-new ideological vision. In Confucius's thought , "the doctrine of the mean"wisdom can be understood as a kind of way of thinking, a kind of political ideal, a kind of life attitude, a kind of ideal personality, a perfect aesthetic ideal and so on. "the doctrine of the mean" wisdom left its deep impression and marks in Chinese traditional political philosophy, philosophy of life, aesthetics and artistic philosophy in its own way. And also, it has established the basic and profound characteristics and direction of Chinese traditional culture. Along with Confucianism's as its own development and evolution, "doctrine of the mean"thought also has been expanding and enriching, and entrusts with all sorts ofdifferent interpretations and explanations, is becoming the essencial spirit and the core value nerve of Confucianism and soaks deeply in the blood of Chinese culture. Therefore, understanding of Confucius "doctrine of the mean" wisdom equitably is very important for understanding "the doctrine of the mean"inner logic of thinking, for understanding the trajectories of development of Confucianism itself, for understanding the energetic quality of Confucianism, as well as for understanding our own culture cultural root and background, has the very vital significance.

The Differences of Subcellular Ca²⁺ Distribution in Cucumber Seedling Leaves under NO₃⁻ Stress

Feng Juan Yang,Xiu Feng Wang,Min Wei 한국원예학회 2006 한국원예학회 기타간행물 Vol.- No.-

Conceptual Cluster-based Large-scale Ontology Compression Approach

Yang Feng,Qin Ziting 보안공학연구지원센터 2016 International Journal of Database Theory and Appli Vol.9 No.7

With the development of semantic web and ontology application, there is a large number of ontology whose scale is large and the structure is complex in different fields. The existing mapping method and mapping system perform well when dealing with the mapping between a lightweight small ontology. However, when comes to the large-scale ontology, it is full of challenges to the methods and systems。To this end, this paper proposes a method of ontology compression based on conceptual cluster to compress. Firstly, it calculates the semantic similarity and semantic correlation of ontology concepts with the DICE coefficient method and the information entropy technology to get semantic relation. Secondly according to the semantic relations, it carries on the conceptual cluster in the concept space so that the concept of semantic relations closely together in groups. The concept of cluster in space is reduced, and the "noise concept" which is independent of the mapping is removed, and the purpose of the large-scale ontology compression is realized. Experimental results show that the method is so effective that it can compress the volume of large-scale ontology in the mapping problems.

Study on the Buckling Behaviour of Cold-Formed Angles in Transmission Towers

Fengli Yang,Junke Han,Jingbo Yang,Zhenbao Li 한국강구조학회 2011 International Journal of Steel Structures Vol.11 No.4

Considering the structural characteristics of transmission towers, four sections of cold-formed angles with different slenderness ratios and constrained types were selected for the experimental and numerical study. Experiments and finite element analysis for the ultimate loads of the compression cold-formed angles were carried out. The finite element model well predicts the buckling behaviour of the cold-formed members. For the axial compression members, the load-strain curves as well as the ultimate loads were analyzed, and the experimental ultimate loads were compared with those of calculated by the applicable standards. It shows that the applicable standards aren’t adaptive to the strength design of the compression cold-formed members in transmission towers. Through the analysis of the experimental and FEA results, the fitting curve of the stability coefficients for the cold-formed members in transmission towers was determined. The ultimate loads calculated by the fitting curve are well agreed with the experimental values, especially for the members with relatively low slenderness ratios. Some modification suggestions were proposed for the calculation of the ultimate load for the axial compression cold-formed angle. Experimental analysis on the cold-formed members of the other five constrained types was completed, and the modification formulas of the slenderness ratios for members of different constrained types were obtained.

A Comparison of Developmental Trajectories of Prepulse Inhibition between Male and Female Rats

Yang Yang,Yun'ai Su,Chunmei Guo,Yu Feng,Jitao Li,Tianmei Si 대한정신약물학회 2010 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.8 No.3

Objective: Various studies have demonstrated that childhood and adolescence are critical periods of brain development characterized by both dramatic changes and sexual dimorphism in anatomy, physiology and cognition. Prepulse inhibition (PPI) is an operational model of sensorimotor gating process, but data concerning the interactions of sex and normal ontogeny of PPI is of a particular paucity. Methods: We led a longitudinal study to compare the PPI between male and female Sprague-Dawley rats during postnatal day 23 to 43. Results: We found that the PPI of both male and female rats increased during this period. We also found that the PPI of male and female rats had different developmental trajectories when the prepulse intensity was 20 dB [A] above background, a result similar with a previous study done in humans. Conclusion: The finding confirms the face validity of PPI as a model of information processing across species and supports its utilization for investigation of potential aetiological factors implicated in mental disorders.

MAS-based Model for Evaluating Train Timetables to Minimise the Waiting Time

Feng Chen,Huimin Yang,Yang Yang 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.3

In recent years, continuous developments in urban rail transit have led to automatic fare collection systems being installed in various cities. This not only improves passenger travel efficiency but also allows information on the behaviour of passengers in the system to be collected and used to optimise the train timetable. This paper presents an optimisation model for determining the optimal headway for a train timetable. In addition, a Multi-Agent System (MAS)-based model is presented for simulating the interactions between passengers and trains to estimate the locations of passengers in a rail network at a given time. The MAS-based model was applied to simulating the actual operation and predicted long-term demand of a newly built metro line to validate its applicability to urban rail transit networks, and the results were used to determine the optimal headway for solving the mismatch between the transport capacity according to the timetable and demand according to the passenger flow volume. The simulation results can be used as a data basis for the design and adjustment of train operating plans.

Effects of maternal undernutrition during late pregnancy on the regulatory factors involved in growth and development in ovine fetal perirenal brown adipose tissue

Yang Huan,Ma Chi,Zi Yang,Zhang Min,Liu Yingchun,Wu Kaifeng,Gao Feng 아세아·태평양축산학회 2022 Animal Bioscience Vol.35 No.7

Objective: The experiment was conducted to evaluate the effects of maternal undernutrition during late pregnancy on the expressions of genes involved in growth and development in ovine fetal perirenal brown adipose tissue (BAT). Methods: Eighteen ewes with singleton fetuses were allocated to three groups at day 90 of pregnancy: restricted group 1 (RG1, 0.33 MJ metabolisable energy [ME]/kg body weight [BW]0.75/d, n = 6), restricted group 2 (RG2, 0.18 MJ ME/kg BW0.75/d, n = 6), and a control group (CG, ad libitum, 0.67 MJ ME/kg BW0.75/d, n = 6). The fetuses were removed at day 140 of pregnancy. All data were analyzed by using the analysis of variance procedure. Results: The perirenal fat weight (p = 0.0077) and perirenal fat growth rate (p = 0.0074) were reduced in RG2 compared to CG. In fetal perirenal BAT, the protein level of uncoupling protein 1 (UCP1) (p = 0.0001) was lower in RG1 and RG2 compared with CG and UCP1 mRNA expression (p = 0.0265) was decreased in RG2. The protein level of myogenic factor 5 (Myf5) was also decreased in RG2 (p = 0.0001). In addition, mRNA expressions of CyclinA (p = 0.0109), CyclinB (p = 0.0019), CyclinD (p = 0.0015), cyclin-dependent kinase 1 (CDK1) (p = 0.0001), E2F transcription factor 1 (E2F1) (p = 0.0323), E2F4 (p = 0.0101), and E2F5 (p = 0.0018) were lower in RG1 and RG2. There were decreased protein expression of peroxisome proliferator-activated receptor-γ (PPARγ) (p = 0.0043) and mRNA expression of CCAAT/ enhancer-binding protein-α (C/EBPα) (p = 0.0307) in RG2 and decreased PPARγ mRNA expression (p = 0.0008) and C/EBPα protein expression (p = 0.0015) in both RG2 and RG1. Furthermore, mRNA expression of bone morphogenetic protein 4 (BMP4) (p = 0.0083) and BMP7 (p = 0.0330) decreased in RG2 and peroxisome proliferator-activated receptor co-activator-1α (PGC-1α) reduced in RG2 and RG1. Conclusion: Our observations support that repression of regulatory factors promoting differentiation and development results in the inhibition of BAT maturation in fetal perirenal fat during late pregnancy with maternal undernutrition. Objective: The experiment was conducted to evaluate the effects of maternal undernutrition during late pregnancy on the expressions of genes involved in growth and development in ovine fetal perirenal brown adipose tissue (BAT).Methods: Eighteen ewes with singleton fetuses were allocated to three groups at day 90 of pregnancy: restricted group 1 (RG1, 0.33 MJ metabolisable energy [ME]/kg body weight [BW]^0.75/d, n = 6), restricted group 2 (RG2, 0.18 MJ ME/kg BW^0.75/d, n = 6), and a control group (CG, <i>ad libitum</i>, 0.67 MJ ME/kg BW^0.75/d, n = 6). The fetuses were removed at day 140 of pregnancy. All data were analyzed by using the analysis of variance procedure.Results: The perirenal fat weight (p = 0.0077) and perirenal fat growth rate (p = 0.0074) were reduced in RG2 compared to CG. In fetal perirenal BAT, the protein level of uncoupling protein 1 (UCP1) (p = 0.0001) was lower in RG1 and RG2 compared with CG and UCP1 mRNA expression (p = 0.0265) was decreased in RG2. The protein level of myogenic factor 5 (Myf5) was also decreased in RG2 (p = 0.0001). In addition, mRNA expressions of <i>CyclinA</i> (p = 0.0109), <i>CyclinB</i> (p = 0.0019), <i>CyclinD</i> (p = 0.0015), cyclin-dependent kinase 1 (<i>CDK1</i>) (p = 0.0001), E2F transcription factor 1 (<i>E2F1</i>) (p = 0.0323), <i>E2F4</i> (p = 0.0101), and <i>E2F5</i> (p = 0.0018) were lower in RG1 and RG2. There were decreased protein expression of peroxisome proliferator-activated receptor-γ (PPARγ) (p = 0.0043) and mRNA expression of CCAAT/ enhancer-binding protein-α (<i>C/EBPα</i>) (p = 0.0307) in RG2 and decreased <i>PPARγ</i> mRNA expression (p = 0.0008) and C/EBPα protein expression (p = 0.0015) in both RG2 and RG1. Furthermore, mRNA expression of bone morphogenetic protein 4 (<i>BMP4</i>) (p = 0.0083) and <i>BMP7</i> (p = 0.0330) decreased in RG2 and peroxisome proliferator-activated receptor co-activator-1α (<i>PGC-1α</i>) reduced in RG2 and RG1.Conclusion: Our observations support that repression of regulatory factors promoting differentiation and development results in the inhibition of BAT maturation in fetal perirenal fat during late pregnancy with maternal undernutrition.