Behavior and Mechanism of Void Welding Under Thermal Mechanical Coupling

Fei Chen,Xitao Wang,Huiqin Chen,Shue Dang 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.7

Shrinkage cavity, microporosity, blowhole and the likes are the typical void defects in ingot. Only through reasonable hightemperature deformation and heat preservation process can the void defects be closed and welded to ensure the high qualityof forgings. However, there are few researches on the welding behavior of voids, and the understanding of the void weldingmechanism is still insufficient. In order to further study the welding behavior of void and explore the welding mechanism,the welding process of void and microstructure evolution around void under thermal mechanical coupling were studied byphysical simulation. The results show that heating temperature, holding time, plastic deformation play an important role invoid welding. The void welding degree increases with the increase of heating temperature, holding time and plastic deformation. Besides, there are three main welding mechanisms for void defects, including the volume of microvoids decreasesdue to vacancy diffusion, the void welding mechanism caused by the austenite-ferrite transformation at lower temperaturesand the void welding mechanism caused by recrystallization and grain growth of austenite grains at higher temperatures.

Interview with Professor Fei-Ling Wang, author of The China Order: Centralia, World Empire, and the Nature of Chinese Power (2017)

Jaewoo Choo(토론자),Fei-Ling Wang(토론자) 동북아역사재단 2017 Journal of Northeast Asian History Vol.14 No.2

Controlling Ejection State of a Pneumatic Micro-droplet Generator Through Machine Vision Methods

Fei Wang,Yiwei Wang,Weijie Bao,Hui Zhang,Jiangeng Li,Zhihai Wang 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.21 No.4

Pneumatic micro-droplet ejection is a printing technique that has potential applications in many fi elds, especially in thefi eld of bio-printing. The ejection is via a solenoid valve being briefl y turned on, so that high pressure gas enters the liquidreservoir, forming a gas pressure pulse, forcing the liquid out through a tiny nozzle to form a micro-droplet. For bio-printingapplications, the bio-inks are typically non-standard. The diffi culties are not only that the initial working parameters arediffi cult to set, but also the working conditions change over time in many cases. In order to maintain a stable single-dropejection state, a machine vision based ejection monitoring was designed to obtain the number, positions and sizes of thedroplets for each ejection, and a feedback control is realized by adjusting the “ON” time of the solenoid valve or the gaspressure at the front end of the solenoid valve.

Microstructure and phase constitution near the interface of Cu/3003 torch brazing using Al-Si-La-Sr filler

Fei Yan,Daorong Xu,S.C. Wu,Qinde Sun,Chunming Wang,Yajun Wang 대한기계학회 2012 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.26 No.12

It has been mainly studied in this paper on brazing of Cu to Al using Al–Si filler metal. The optimized scanning rate of 2.5 mm/s is first obtained through simulating the temperature field of Cu-Al brazing process based on ANSYS software. Then the brazing of Cu-C11000 to Al-3003 using Al–Si–La–Sr filler is carried out by torch brazing technology. It is found that the brazing seam region is mainly consisted of α-Al solid solution and CuAl2 IMC. Further experimental results also show that the rare earth element La in filler metal can not only refine the grain, but also promote the dispersion of intermetallic compounds into the brazing seam, which significantly improves the brazing seam microstructure and mechanical properties of the joints.

Geometric Optimization of a Mathematical Model of Radiofrequency Ablation in Hepatic Carcinoma

Wang, Kai-Feng,Pan, Wei,Wang, Fei,Wang, Gao-Feng,Madhava, Pai,Pan, Hong-Ming,Kong, De-Xing,Liu, Xiang-Guan Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.10

Radio frequency ablation (RFA) is an effective means of achieving local control of liver cancer. It is a particularly suitable mode of therapy for small and favorably located tumors. However, local progression rates are substantially higher for large tumors (>3.0 cm). In the current study, we report on a mathematical model based on geometric optimization to treat large liver tumors. A database of mathematical models relevant to the configuration of liver cancer was also established. The specific placement of electrodes and the frequency of ablation were also optimized. In addition, three types of liver cancer lesion were simulated by computer guidance incorporating mathematical models. This approach can be expected to provide a more effective and rationale mechanism for employing RFA in the therapy of hepatic carcinoma.

Mechanical Bending Property of Ultra-High Strength Steel Sheets IN Roll Forming Process

Fei Han,Yun Wang,Zai-Lin Wang 한국정밀공학회 2018 International Journal of Precision Engineering and Vol.19 No.12

Ultra-high strength steel (UHSS) plays an important role in the automotive lightweight industry owing to its insubstantial weight and high specific strength. Roll forming is one of the effective forming processes for UHSS in the steel industry. In this study, the minimum bending radius is determined by roll forming experiments, taking into account the 1200MPa level of the V-profiled parts of UHSS. The ductile fracture criterion (DFC), which considers both the “tensile ductile fracture” and “shear ductile fracture,” is applied to predict the fracture of sheets in the roll forming process, where bending is the main deformation mode. A set of rolls is designed to investigate the fracture behavior in the roll forming process. In addition, finite element models (FEMs) are built and four sets of experiments are conducted to calibrate the fracture of the V-profiled parts for R/T = 1, 2, 3, and 4. Furthermore, the fracture time and fracture location of the V-profiled parts for R/T = 1 and 2 are predicted and the prediction results agree with the experimental results.

Role of Nucleation-Promoting Factors in Mouse Early Embryo Development

Wang, Qiao-Chu,Liu, Jun,Wang, Fei,Duan, Xing,Dai, Xiao-Xin,Wang, Teng,Liu, Hong-Lin,Cui, Xiang-Shun,Sun, Shao-Chen,Kim, Nam-Hyung Cambridge University Press 2013 Microscopy and microanalysis Vol.19 No.3

<B>Abstract</B><P>During mitosis nucleation-promoting factors (NPFs) bind to the Arp2/3 complex and activate actin assembly. JMY and WAVE2 are two critical members of the NPFs. Previous studies have demonstrated that NPFs promote multiple processes such as cell migration and cytokinesis. However, the role of NPFs in development of mammalian embryos is still unknown. Results of the present study show that the NPFs JMY and WAVE2 are critical for cytokinesis during development of mouse embryos. Both JMY and WAVE2 are expressed in mouse embryos. After injection of JMY or WAVE2 siRNA, all embryos failed to develop to the morula or blastocyst stages. Moreover, using fluorescence intensity analysis, we found that the expression of actin decreased, and multiple nuclei were observed within a single cell indicating that NPFs-induced actin reduction caused the failure of cell division. In addition, injection of JMY and WAVE2 siRNA also caused ARP2 degradation, indicating that involvement of NPFs in development of mouse embryos is mainly through regulation of ARP2/3-induced actin assembly. Taken together, these data suggested that WAVE2 and JMY are involved in development of mouse embryos, and their regulation may be through a NPFs-Arp2/3-actin pathway.</P>

Advances in CRISPR-Cas systems for RNA targeting, tracking and editing

Wang, Fei,Wang, Lianrong,Zou, Xuan,Duan, Suling,Li, Zhiqiang,Deng, Zixin,Luo, Jie,Lee, Sang Yup,Chen, Shi Elsevier 2019 BIOTECHNOLOGY ADVANCES Vol.37 No.5

<P><B>Abstract</B></P> <P>Clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein (Cas) systems, especially type II (Cas9) systems, have been widely used in gene/genome targeting. Modifications of Cas9 enable these systems to become platforms for precise DNA manipulations. However, the utilization of CRISPR-Cas systems in RNA targeting remains preliminary. The discovery of type VI CRISPR-Cas systems (Cas13) shed light on RNA-guided RNA targeting. Cas13d, the smallest Cas13 protein, with a length of only ~930 amino acids, is a promising platform for RNA targeting compatible with viral delivery systems. Much effort has also been made to develop Cas9, Cas13a and Cas13b applications for RNA-guided RNA targeting. The discovery of new RNA-targeting CRISPR-Cas systems as well as the development of RNA-targeting platforms with Cas9 and Cas13 will promote RNA-targeting technology substantially. Here, we review new advances in RNA-targeting CRISPR-Cas systems as well as advances in applications of these systems in RNA targeting, tracking and editing. We also compare these Cas protein-based technologies with traditional technologies for RNA targeting, tracking and editing. Finally, we discuss remaining questions and prospects for the future.</P> <P><B>Highlights</B></P> <P> <UL> <LI> RNA targeting and editing are becoming increasingly important </LI> <LI> CRISPR-Cas systems are advancing for RNA targeting, tracking and editing </LI> <LI> The type VI CRISPR-Cas systems are useful for RNA-guided RNA targeting </LI> <LI> Use of Cas9 and Cas13 will advance RNA-targeting technologies </LI> </UL> </P>

ACOX1 destabilizes p73 to suppress intrinsic apoptosis pathway and regulates sensitivity to doxorubicin in lymphoma cells

( Fei-meng Zheng ),( Wang-bing Chen ),( Tao Qin ),( Li-na Lv ),( Bi Feng ),( Yan-ling Lu ),( Zuo-quan Li ),( Xiao-chao Wang ),( Li-ju Tao ),( Hong-wen Li ),( Shu-you Li ) 생화학분자생물학회(구 한국생화학분자생물학회) 2019 BMB Reports Vol.52 No.9

Lymphoma is one of the most curable types of cancer. However, drug resistance is the main challenge faced in lymphoma treatment. Peroxisomal acyl-CoA oxidase 1 (ACOX1) is the rate-limiting enzyme in fatty acid β-oxidation. Deregulation of ACOX1 has been linked to peroxisomal disorders and carcinogenesis in the liver. Currently, there is no information about the function of ACOX1 in lymphoma. In this study, we found that upregulation of ACOX1 promoted proliferation in lymphoma cells, while downregulation of ACOX1 inhibited proliferation and induced apoptosis. Additionally, overexpression of ACOX1 increased resistance to doxorubicin, while suppression of ACOX1 expression markedly potentiated doxorubicin-induced apoptosis. Interestingly, downregulation of ACOX1 promoted mitochondrial location of Bad, reduced mitochondrial membrane potential and provoked apoptosis by activating caspase-9 and caspase-3 related apoptotic pathway. Overexpression of ACOX1 alleviated doxorubicin-induced activation of caspase-9 and caspase-3 and decrease of mitochondrial membrane potential. Importantly, downregulation of ACOX1 increased p73, but not p53, expression. p73 expression was critical for apoptosis induction induced by ACOX1 downregulation. Also, overexpression of ACOX1 significantly reduced stability of p73 protein thereby reducing p73 expression. Thus, our study indicated that suppression of ACOX1 could be a novel and effective approach for treatment of lymphoma. [BMB Reports 2019; 52(9): 566-571]

Color Analysis for the Quantitative Aesthetics of Qiong Kiln Ceramics

Wang, Fei,Cha, Hang,Leng, Lu Korea Multimedia Society 2020 The journal of multimedia information system Vol.7 No.2

The subjective experience would degrade the current artificial artistic aesthetic analysis. Since Qiong kiln ceramics have a long history and occupy a very important position in ceramic arts, we employed computer-aided technologies to quickly automatically accurately and quantitatively process a large number of Qiong kiln ceramic images and generate the detailed statistical data. Because the color features are simple and significant visual characteristics, the color features of Qiong kiln ceramics are analyzed for the quantitative aesthetics. The Qiong kiln ceramic images are segmented with GrabCut algorithm. Three moments (1st-order, 2nd-order, and 3rd-order) are calculated in two typical color spaces, namely RGB and HSV. The discrimination powers of the color features are analyzed according to various dynasties (Tang Dynasty, Five Dynasties, Song Dynasty) and various utensils (Pot, kettle, bowl), which are helpful to the selection of the discriminant color features among various dynasties and utensils. This paper is helpful to promoting the quantitative aesthetic research of Qiong kiln ceramics and is also conducive to the research on the aesthetics of other ceramics.