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.

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.

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.

Nationalism in China

Yang, Feng Tai 서강대학교 동아연구소 1990 東亞 硏究 Vol.- No.20

An efficient and thermally stable interconnecting layer for tandem organic solar cells

Yang, Feng,Kang, Dong-Won,Kim, Yong-Sang Elsevier 2017 SOLAR ENERGY -PHOENIX ARIZONA THEN NEW YORK- Vol.155 No.-

<P><B>Abstract</B></P> <P>We report a novel interconnecting layer (ICL) consisting of MoO<SUB>3</SUB>/Au/Al/ZnO for efficient operation of inverted homo-tandem organic solar cells employing poly(3-hexylthiophene) (P3HT) and (6,6)-phenyl C61-butyric acid methyl ester (PCBM). It was found that the ultrathin metal bilayer of Au/Al, a few nanometers, can align the energy levels and play a significant role in the charge extraction and recombination within the ICL. And the ICL showed an electrically ohmic-contact, high transmittance and very planar morphology for tandem application. The performance of air-fabricated homo-tandem organic solar cells with this new ICL delivered an average power conversion efficiency (PCE) of 3.0%, which is very close to the PCE of 3.3% from the state-of-the-art P3HT:PCBM based homo-tandem organic solar cells. Meanwhile, thermal stability tests at an elevated temperature of 150°C for 12h showed stable ICL with successful operation.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We suggest a novel interconnecting layer (ICL) of MoO<SUB>3</SUB>/Au/Al/ZnO for tandem cell. </LI> <LI> The ICL with Au/Al works efficiently for charge recombination and ohmic-contact. </LI> <LI> The ICL is highly transparent and morphologically planar, suitable for tandem cell. </LI> <LI> The ICL is thermally-stable in organic tandem cell under air-annealing at 150°C. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Two case studies on structural analysis of transmission towers under downburst

Yang, FengLi,Zhang, HongJie Techno-Press 2016 Wind and Structures, An International Journal (WAS Vol.22 No.6

Downbursts are of great harm to transmission lines and many towers can even be destroyed. The downburst wind field model by Chen and Letchford was applied, and the wind loads of two typical transmission towers in inland areas and littoral areas were calculated separately. Spatial finite element models of the transmission towers were established by elastic beam and link elements. The wind loads as well as the dead loads of conductors and insulators were simplified and applied on the suspension points by concentrated form. Structural analysis on two typical transmission towers under normal wind and downburst was completed. The bearing characteristics and the failure modes of the transmission towers under downburst were determined. The failure state of tower members can be judged by the calculated stress ratios. It shows that stress states of the tower members were mainly controlled by 45 degree wind load. For the inland areas with low deign wind velocity, though the structural height is not in the highest wind velocity zone of downburst, the wind load under downburst is much higher than that under normal wind. The main members above the transverse separator of the legs will be firstly destroyed. For the littoral areas with high deign wind velocity, the wind load under downburst is lower than under normal wind. Transmission towers are not controlled by the wind loads from downbursts in design process.

Long non-coding RNA RP11-6O2.4 indicates poor prognosis and suppresses cell cycle progression through the p38-MAPK signaling pathway in gastric cancer

Yang Feng,Zhiming Fu,Yajun Luo,Wang Tan,Zilin Liu,Pengcheng Ye,Fei Lu,Wanping Xiang,Linghan Tang,Lin Yao,Mengyun Song,Qingmei Huang,Yilun Liu,Jiangwei Xiao 대한독성 유전단백체 학회 2019 Molecular & cellular toxicology Vol.15 No.3

Backgrounds: The role of long non-coding RNAs (lncRNA) in gastric cancer (GC) has been highlighted in studies conducted over the past decade. However, the potential clinical value and the mechanisms of action of RP11-6O2.4 in GC have not been thoroughly elucidated to date. The specific aim of the present study was to assess RP11-6O2.4 and to explore its role in human GC. Methods: Quantitative real-time polymerase chain reaction (qPCR) was performed to analyze the expression levels of RP11-6O2.4 in GC tissues, paired adjacent noncancerous tissues (ANTs) and GC cell lines. In addition, the correlation between RP11-6O2.4 expression and the clinical characteristics and prognosis of patients with GC was statistically analyzed. The effects of RP11- 6O2.4 on the GC cell cycle transformation through the p38-MAPK signaling pathway were explored by flow cytometry, qPCR and Western blot analysis after treatment with SB203580, a p38MAPK specific inhibitor, in vitro. Results: The expression levels of RP11-6O2.4 in GC tissues were significantly lower than the paired ANTs (P<0.05). In addition, RP11-6O2.4 expression was significantly lower in cases with older age, longer maximum tumor diameter, higher ASA grade and deeper invasive depth (P<0.05). RP11-6O2.4 expression was significantly higher in cases with well/middle differentiation than poor/no differentiation; higher in cases without lymph node metastasis than in lymph node metastasis; and higher in cases in stage Ⅰ/Ⅱ than in stage Ⅲ/Ⅳ. An in vitro assay showed that RP11-6O2.4 induced G0/ G1 phase cell cycle arrest, likely by regulating the p38- MAPK signaling pathway. Conclusion: The above mentioned data suggested that RP11-6O2.4 was a tumor-suppressor gene in GC. RP11- 6O2.4 might play an important role in the cell cycle transformation by regulating the p38-MAPK signaling pathway, thereby representing a specific biomarker and a potential molecular target for the treatment of GC.

Multiscale Spatial Position Coding under Locality Constraint for Action Recognition

Yang, Jiang-feng,Ma, Zheng,Xie, Mei The Korean Institute of Electrical Engineers 2015 Journal of Electrical Engineering & Technology Vol.10 No.4

– In the paper, to handle the problem of traditional bag-of-features model ignoring the spatial relationship of local features in human action recognition, we proposed a Multiscale Spatial Position Coding under Locality Constraint method. Specifically, to describe this spatial relationship, we proposed a mixed feature combining motion feature and multi-spatial-scale configuration. To utilize temporal information between features, sub spatial-temporal-volumes are built. Next, the pooled features of sub-STVs are obtained via max-pooling method. In classification stage, the Locality-Constrained Group Sparse Representation is adopted to utilize the intrinsic group information of the sub-STV features. The experimental results on the KTH, Weizmann, and UCF sports datasets show that our action recognition system outperforms the classical local ST feature-based recognition systems published recently.

INTERFACIAL ENGINEERING FOR SOLUTION-PROCESSED METAL OXIDE BASED PEROVSKITE SOLAR CELLS

Feng Yang,Naying Jin,Yong-Sang Kim,Dong-Won Kang 한국신재생에너지학회 2017 AFORE Vol.2017 No.11

ELECTRIC-HYDRAULIC COMPOUND CONTROL ANTI-LOCK BRAKING SYSTEM

Feng Yang,Xin Chen,Dong Guo,Mingmao Hu,Ziwen Liao,Zhongcheng Fu,Qingshan Gong 한국자동차공학회 2022 International journal of automotive technology Vol.23 No.6

An anti-lock control strategy for electric-hydraulic compound braking is proposed to improve the emergency braking safety of a hub motor electric vehicle. Based on the half-vehicle braking longitudinal dynamics model, the optimal control is solved to obtain the total braking torque corresponding to each wheel. A fuzzy algorithm is used to determine the proportion coefficient of the motor based on the battery state of charge coefficient (SOC) and the motor speed constraints on the motor braking, and the total braking torque is distributed. The hydraulic and motor braking torques obtained from the allocation are input as reference values to the electric-hydraulic compound braking system, and the output braking torque is fed back into the CarSim vehicle model. The proposed electric-hydraulic compound ABS control strategy is also validated in the co-simulation of CarSim and MATLAB/Simulink on high, medium and low adhesion road surfaces.