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.

Relationship Between Dry Ports and Regional Economy: Evidence from Yangtze River Economic Belt*

Yan Feng LIU,Chong Bae LEE,Guan Qiu QI,Kum Fai YUEN,Miao SU 한국유통과학회 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.5

With the evolution of containerization and globalization of supply chains, aspects of port functions have made the transition from the sea to the inland region that forms the dry port. To explore the relationship between dry ports and regional economic development, this study uses a gravity model and forecast model to analyze 1,040 observations in 104 cities (22 dry port cities) along the Yangtze River Economic Belt (YREB) from 2008 to 2017. The model includes economic variables, logistics variables, foreign relations variables, and human capital variables. It was found that the dry port is positively correlated with trade volume. Compared with a city without a dry port, the trade volume of a city with a dry port will increase 0.099 times. It can be concluded that a dry port is crucial for the economic development of the YREB. It was also found that per capita GDP as an economic variable, road area and rail number as logistics variables, and foreign relation variables are positively correlated with trade volume, while the human capital variable has no significant effect on trade volume. In addition, governmental policy implications are addressed from the aspects of dry port and industry cluster caused by foreign investment.

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.

A Monascus pilosus MS-1 strain with high-yield monacolin K but no citrinin

Yanli Feng,Wanping Chen,Fusheng Chen 한국식품과학회 2016 Food Science and Biotechnology Vol.25 No.4

Monacolin K (MK) produced by Monascus spp. is mostly used to regulate cholesterol level,while it can be contaminated by citrinin, a mycotoxin yielded by some Monascus strains. To developproduction of citrinin-free MK, an M. sp. MS-1 strain, identified as M. pilosus by morphologies andinternal transcribed spacer sequences analysis, was isolated from red fermented rice. After 14 days offermentation, yields of citrinin-free MK could be up to 0.58 mg/mL and 16.45 mg/g in liquid- and solidstatefermentation products under optimal conditions, respectively. Further determination revealedthat no citrinin biosynthesis related genes such as ctnA, pksCT, ctnE, and ctnR were detected. Thus,HPLC combined with citrinin-related gene analyses can be used for rapid screening of non-citrininproduction Monascus strains.

Salivary Pepsin as an Intrinsic Marker for Diagnosis of Sub-types of Gastroesophageal Reflux Disease and Gastroesophageal Reflux Disease-related Disorders

( Yan-jun Wang ),( Xiu-qiong Lang ),( Dan Wu ),( Yu-qin He ),( Chun-hui Lan ),( Xiao-xiao ),( Bin Wang ),( Duo-wu Zou ),( Ji-min Wu ),( Yong-bin Zhao ),( Peter W Dettmar ),( Dong-feng Chen ),( Min Yan 대한소화기 기능성질환·운동학회 2020 Journal of Neurogastroenterology and Motility (JNM Vol.26 No.1

Background/Aims To determine the value of salivary pepsin in discriminating sub-types of gastroesophageal reflux disease (GERD) and GERD-related disorders. Methods Overall, 322 patients with different sub-types of GERD and 45 healthy controls (HC) were studied. All patients took Gastroesophageal Reflux Disease Questionnaire (GerdQ) and underwent endoscopy and 24-hour esophageal pH monitoring and manometry. Salivary pepsin concentration (SPC) was detected by using colloidal gold double-antibody immunological sandwich assay. Oral esomeprazole treatment was administrated in the patients with non-erosive reflux disease (NERD) and extra-esophageal symptoms (EES). Results Compared to HC, patients with erosive esophagitis, NERD, EES, EES plus typical GERD symptoms, or Barrett’s esophagus had a higher prevalence of saliva and SPC (all P < 0.001). There was no significant difference in the positive rate for pepsin in patients with functional heartburn or GERD with anxiety and depression, compared to HC. After esomeprazole treatment, the positive rate and SPC were significantly reduced in NERD (both P < 0.001) and in EES (P = 0.001 and P = 0.002, respectively). Of the 64 NERD patients, 71.9% (n = 46) were positive for salivary pepsin, which was significantly higher than the rate (43.8%, n = 28) of pathological acid reflux as detected by 24-hour esophageal pH monitoring (P = 0.002). Conclusions Salivary pepsin has an important significance for the diagnosis of GERD and GERD-related disorders. Salivary pepsin and 24-hour esophageal pH monitoring may complement with each other to improve the diagnostic efficiency.

Enhanced Hierarchical Model of Object Recognition Based on Saliency Map and Keypoint

Yan-Feng Lu,Tae-Koo Kang,Hua-Zhen Zhang,Dong-Sung Pae,Myo-Taeg Lim 제어로봇시스템학회 2015 제어로봇시스템학회 국내학술대회 논문집 Vol.2015 No.5

Implementation of online model updating with ANN method in substructure pseudo-dynamic hybrid simulation

Yan Hua Wang,Jing Lv,Yan Feng,Bo Wen Dai,Cheng Wang,Jing Wu,Zi Yan Chen 국제구조공학회 2021 Smart Structures and Systems, An International Jou Vol.28 No.2

Substructure pseudo-dynamic hybrid simulation (SPDHS) is an advanced structural seismic testing method which combines physical experiment and numerical simulation. Generally, the key components which display nonlinearity first are taken as experimental substructures for actual test, and the remaining parts are modeled in simulation. Model updating techniques can be effectively applied to enhance the model precision of nonlinear numerical elements. Specifically, the constitutive model of the experimental substructure is identified online by the instantaneously-measured data, and the corresponding numerical elements with similar hysteretic behaviors are updated synchronously. Artificial neural network (ANN) can recognize the system which cannot be represented by definite numerical model, and thus avoids the structural response distortion caused by the inherent numerical model defects. In this study, a framework for online model updating in SPDHS with ANN method is expanded to implement actual test validation. Moreover, the effectiveness of ANN method is demonstrated by practical tests of a two-story frame model with bending dampers. Additionally, the unscented Kalman filter technique and offline ANN identification approach are both examined in the test validation. The experimental results show that, under the identical loading history, the online ANN method can significantly reduce the model errors and improve the accuracy of SPDHS.

Efficacy and Safety of the Safe Triangular Working Zone Approach in Percutaneous Vertebroplasty for Spinal Metastasis

Yan Bi Cong,Fan Yan Feng,Tian Qing Hua,Wang Tao,Huang Zhi Long,Song Hong Mei,Li Ying,Jiao Lei,Wu Chun Gen 대한영상의학회 2022 Korean Journal of Radiology Vol.23 No.9

Objective: This study aimed to assess the technical feasibility, efficacy, and safety of the safe triangular working zone (STWZ) approach applied in percutaneous vertebroplasty (PV) for spinal metastases involving the posterior part of the vertebral body. Materials and Methods: We prospectively enrolled 87 patients who underwent PV for spinal metastasis involving the posterior part of the vertebral body, with or without the STWZ approach, from January 2019 to April 2022. Forty-nine patients (27 females and 22 males; mean age ± standard deviation [SD], 57.2 ± 11.6 years; age range, 31–76 years) were included in group A (with STWZ approach), accounting for 54 vertebrae. Thirty-eight patients (18 females and 20 males; 59.1 ± 10.9 years; 29–81 years) were included in group B (without STWZ approach), accounting for 57 vertebrae. Patient demographics, procedure-related variables, and pain relief as assessed using the visual analog scale (VAS) were collected at different time points. Tumor recurrence in the vertebrae after PV was analyzed using Kaplan–Meier curves. Results: The STWZ approach was successful from T1 to L5 without severe complications. Cement filling was satisfactory in 47/54 (87.0%) and 25/57 (43.9%) vertebrae in groups A and B, respectively (p < 0.001). Cement leakage was not significantly different between groups A and B (p = 1.000). Mean VAS score ± SD before and 1 week and 1, 3, 6, 9, and 12 months after PV were 7.6 ± 1.8, 4.2 ± 2.0, 2.7 ± 1.9, 1.9 ± 1.5, 1.7 ± 1.4, 1.7 ± 1.1, and 1.6 ± 1.3, respectively, in group A and 7.2 ± 1.7, 4.0 ± 1.3, 3.4 ± 1.6, 2.4 ± 1.2, 1.8 ± 1.0, 1.4 ± 0.5, and 1.7 ± 0.9, respectively, in group B. Kaplan–Meier analysis showed a lower tumor recurrence rate in group A than in group B (p = 0.001). Conclusion: The STWZ approach may represent a new, safe, alternative/auxiliary approach to target the posterior part of the vertebral body in the PV for spinal metastases.

Absorption, Translocation, and Remobilization of Cadmium Supplied at Different Growth Stages of Rice

Yan, Yong-Feng,Choi, Doug-Hwan,Kim, Do-Soon,Lee, Byun-Woo 한국작물학회 2010 Journal of crop science and biotechnology Vol.13 No.2

Cadmium (Cd) is absorbed by rice root and transferred into the other rice organs including grain. A solution-culture experiment was conducted to investigate the absorption and distribution of Cd supplied at different growth stages of rice. Two rice cultivars, a japonica 'Chucheong' and a tongil-type 'Milyang23' that exhibit high and low ability of Cd absorption by root and accumulation in grain were grown in culture solution and subjected to 2 ppm $CdCl^2$ treatment for 2 weeks at four different growth stages: before panicle initiation stage (BPI), after panicle initiation stage (API), early ripening stage (ER), and mid-ripening stage (MR). Cd concentration and accumulation in rice organs were measured at harvest. The two rice cultivars accumulated two to three times greater amounts of Cd in grain in the two Cd treatments before heading (BPI and API treatments) than in the Cd treatment after heading (ER and MR treatment). The higher grain Cd accumulation in BPI and API treatments was not attributed to the higher Cd uptake but to the higher translocation from root to shoot and the higher redistribution from shoot to grain than ER and MR treatments These results imply that the remobilization of Cd through phloem during leaf senescence is the major process for Cd accumulation in rice grain rather than direct transport of absorbed Cd through the xylem-phloem transfer to grain. 'Milyang23' absorbed significantly smaller amount of Cd than 'Chucheong'. However, ‘Milyang23' accumulated more than a three times larger amount of Cd in grain compared to 'Chucheong' as the former exhibited the higher root-shoot translocation and shoot-grain remobilization as well. It indicates that the greater Cd translocation from root to shoot and subsequent higher Cd remobilization from shoot to grain, not the higher absorption ability, have led to the higher Cd accumulation and concentration in grain of 'Milyang23'.