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.

京未話劇是認識北京的一面鏡子

馮燕慶 한국중국문화학회 2001 中國學論叢 Vol.12 No.-

在國際文化交流日益頻繁的新世紀, 中國散已經開了對外開放的大門. 在文學藝術領域, 各式各樣的著名文學作品源源不斷地被譯介到國家外, 使世人遷漸認識和了解了有着懲久歷史的古老文明的國度他的昨天, 前天和今天的文化.然而, 作爲話劇,這一西洋泊來的文化藝衛品種, 在中國的歷史狼不太長, 特別是京味話劇的誕生和發展, 還未更多的被世人關注, 和了解. 筆者旨在介紹京味話劇初次走出國門從來曾創造過的輝煌, 竝分析. 探討京味話劇在新的歷史時期發展的前景和走向, 鐵世界深入了解中國, 認識北京, 提供一介審美的感性的舞臺,進一步促進中國和世界的文化交流活動.

Impact of sorption functional media (SFM) from zeolite tailings on the removal of ammonia nitrogen in a biological aerated filter

Yan Feng,Yanzhen Yu,Liping Qiu,Yawen Yang,Zhigang Li,Miaowan Li,Lisha Fan,Yuzhong Guo 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.21 No.1

Haydite and sorption functional media (SFM),made of clinoptilolite tailings, were used as filter media forbiological aerated filter (BAF) to treat synthetic wastewater in parallel. The aim of this work was toevaluate impact of SFM on the removal of ammonia nitrogen in a biological aerated filter reactor underammonium nitrogen shock loads. It could be demonstrated that: (1) the BAF with SFMpresented higherammonia nitrogen removal efficiency than that with haydite; (2) during the phase of higher influentconcentrations SFMs were collecting ammonia nitrogen and can buffer ammonia nitrogen loads anddampen the effluent concentration of ammonia nitrogen; (3) when the influent concentration decreasesammonia nitrogen will desorb from the SFM and can be utilized by the nitrifying bacteria growing on theSFM. Therefore, with the SFM application existing BAF unites can be upgraded and the stability of theoperation process of BAF can be improved significantly.

Study on the Social Adaptation of Chinese Children with Down Syndrome

Yan-xia Wang,Shan-shan Mao,Chun-hong Xie,Yu-feng Qin,Zhi-wei Zhu,Jian-ying Zhan,Jie Shao,Rong Li,Zheng-yan Zhao 연세대학교의과대학 2007 Yonsei medical journal Vol.48 No.3

Functional Analysis of the Inhibitor of Apoptosis Genes in Antheraea pernyi Nucleopolyhedrovirus

Feng Yan,Xiaobei Deng,Junpeng Yan,Jiancheng Wang,Lunguang Yao,Songya lv,Yipeng Qi,Hua Xu 한국미생물학회 2010 The journal of microbiology Vol.48 No.2

The inhibitor of apoptosis proteins (IAP) plays an important role in cell apoptosis. We cloned two novel IAP family members, Ap-iap1 and Ap-iap2, from Antheraea pernyi nucleopolyhedrovirus (ApNPV) genome. Ap-IAP1 contains two baculoviral IAP repeat (BIR) domains followed by a RING domain, but Ap-IAP2 has only one BIR domain and RING. The result of transient expression in Spodoptera frugiperda (Sf21) showed that Ap-iap1 blocked cell apoptosis induced by actinomycin D treatment and also rescued the p35 deficient Autographa californica nucleopolyhedrovirus (AcNPV) to replicate in Sf9 cells, while Ap-iap2 does not have this function. Several Ap-IAP1 truncations were constructed to test the activity of BIRs or RING motif to inhibit cell apoptosis. The results indicated that BIRs or RING of Ap-IAP1 had equally function to inhibit cell apoptosis. Therefore deletion of above both of the above domains could not block apoptosis induced by actinomycin D or rescue the replication of AcMNPV△p35. We also screened two phage-display peptides that might interact with Ap-IAP1.

Fusion Expression and Immunogenicity of EHEC EspA-Stx2A1 Protein: Implications for the Vaccine Development

Yan Cheng,Youjun Feng,Ping Luo,Jiang Gu,Shu Yu,Wei-jun Zhang,Yan-qing Liu,Qing-xu Wang,Quan-ming Zou,Xu-hu Mao 한국미생물학회 2009 The journal of microbiology Vol.47 No.4

Shiga toxin 2 (Stx2) is a major virulence factor for enterohemorrhagic Escherichia coli (EHEC), which is encoded by λ lysogenic phage integrated into EHEC chromosome. Stx2A1, A1 subunit of Stx2 toxin has gathered extensive concerns due to its potential of being developed into a vaccine candidate. However, the substantial progress is hampered in part for the lack of a suitable in vitro expression system. Here we report use of the prokaryotic system pET-28a::espA-Stx2A1/BL21 to carry out the fusion expression of Stx2A1 which is linked to E. coli secreted protein A (EspA) at its N-terminus. Under the IPTG induction, EspA- Stx2A1 fusion protein in the form of inclusion body was obtained successfully, whose expression level can reach about 40% of total bacterial protein at 25°C, much higher than that at 37°C. Western blot test suggested the refolded fusion protein is of excellent immuno-reactivity with both monoclonal antibodies, which are specific to EspA and Stx2A1, respectively. Anti-sera from Balb/c mice immunized with the EspA-Stx2A1 fusion protein were found to exhibit strong neutralization activity and protection capability in vitro and in vivo. These data have provided a novel feasible method to produce Stx2A1 in large scale in vitro, which is implicated for the development of multivalent subunit vaccines candidate against EHEC O157:H7 infections.

In-depth analysis of copycatting products based on economical and managerial viewpoints

FENG YAN,Mingyu ZHANG 인하대학교 정석물류통상연구원 2009 인하대학교 정석물류통상연구원 학술대회 Vol.2009 No.10

Nowadays, the copycatting products (or “Shan Zhai” products in Chinese) especially in mobile phone field are becoming popular in some countries like China due to the low cost and simple imitation in shape and functions. In fact, the copycatting products are facing more and more challenges from intellectual property protection and the risk of price war domestically due to the shortage of innovation. Still, we cannot deny that the copycatting products have certain rationality in some ways like attractive low price, comprehensive functions etc. They rush into the traditional IT industry within more fierce competition. In this paper, the author would analyze the status of the copycatting products in China, the relationship between copycatting and enterprise, the trend of copycatting by using mathematic model respectively.

A Fractional Fourier Transform-Based Approach for Gas-Insulated Switchgear Partial Discharge Recognition

Feng-Chang Gu,Feng-Chang Gu,Bo-Yan Chen 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.5

Partial discharge (PD) is very likely to deteriorate the insulating materials in power facilities. For this sake, PD detection and pattern recognition are treated as an effective approach to diagnosing the high-voltage insulation of power systems. A novel PD feature extraction approach for defect pattern recognition of a gas-insulated switchgear (GIS) is developed and then presented in this paper, using fractional Fourier transform (FrFT). A PD detector is utilized to measure the PD signal of the GIS using an ultra high frequency sensor, which is first transformed to its FrFT as the order ranges from 0 to 1. A 3D characteristic spectrum is then constructed, according to which the fractal parameters are extracted as the constituents of the cluster domains of defect types. Extension matter-element models of the PD defect types are then established according to the experimentally derived PD features. Subsequently, the PD defect type can be directly identified using the correlation degree between a tested pattern and the matter-element models. The pattern recognition performance is investigated on 80 sets of PD patterns, and the performance of the proposed approach is demonstrated accordingly. High accuracy, accompanied with high tolerance, was reached in the presence of noise interference using FrFT.

Cubic s-regular graphs of order 2p³

Feng, Yan-Quan,Kwak, Jin Ho,Xu, Ming-Yao Wiley Subscription Services, Inc., A Wiley Company 2006 Journal of graph theory Vol.52 No.4

<P>A graph is s-regular if its automorphism group acts regularly on the set of its s-arcs. Malnič et al. (Discrete Math 274 (2004), 187–198) classified the connected cubic edge-transitive, but not vertex-transitive graphs of order 2p<SUP>3</SUP> for each prime p. In this article, we determine the s-regularity of all connected cubic symmetric graphs of order 2p<SUP>3</SUP> for each prime p and each s. © 2006 Wiley Periodicals, Inc. J Graph Theory</P>

Applicability Analysis of Microseismic Technology in Tunnel Water Inrush Monitoring

Yan-hao Chen,Shuai Cheng,Li-Ping Li,Jun-yan Yang,Hong-liang Liu,Wen-feng Tu 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.7

Water inrush disaster is one of the most serious geological disasters in tunnel construction. There are still some problems in the existing researches, such as the activity information of surrounding rock is difficult to obtain, the mechanism of water inrush disaster is unclear, the correlation between water inrush disaster and microseismic (MS) information is missing, which have caused the water inrush disaster to be passively controlled. Combining with the practical experience of tunnel engineering, the application problems of MS technology in tunnel engineering is summarized, which provides ideas for monitoring of surrounding rock activity. The formation mechanism of water inrush disaster caused by rock mass fracturing and filling medium instability has been revealed. The MS characteristics of the water inrush channel in different water inrush disasters have also been revealed. The MS response characteristics of water inrush and rockburst disasters are compared, which provides guidance for the improvement of MS monitoring technology and the analysis of effective MS information. The compression failure test of limestone under saturated and natural conditions is carried out. The results show that the presence of water weakens the ability of rock to store energy. The acoustic emission (AE) phenomenon is weaker in the process of saturated limestone failure, which increases the difficulty of AE monitoring. The number of AE events of natural limestone and saturated limestone shows a slow increase to a sudden increase in the process stress loading, which can be regarded as an important precursor of rock failure.