Low-Temperature Synthesis and Characterization of Ti2AlC/TiAl in situ Composites via a Reaction Hot-Pressing Process in the Ti3AlC2-Ti-Al System

Taotao Ai,Ning Yu,Xiaoming Feng,Niansuo Xie,Wenhu Li,Pengju Xia 대한금속·재료학회 2015 METALS AND MATERIALS International Vol.21 No.1

Ti2AlC/TiAl in situ composites were fabricated via a reaction Hot-Pressing Process using Ti3AlC2, Ti, and Alpowders as initial materials. The effect of Ti2AlC content on the phases and microstructure of the as-sinteredcomposites was investigated by XRD and SEM. The mechanical properties such as Vickers hardness, flexuralstrength and fracture toughness of the as-sintered composites were also tested. The products consisted ofTi2AlC, γ-TiAl and α2-Ti3Al as the major phases. Ti2AlC reinforcements were mainly distributed in the grainboundaries, resulting in obvious γ+α2 grain refinement. With increasing Ti3AlC2 content (up to 5 wt%), theVickers hardness, flexural strength and fracture toughness of the as-sintered composite reached the maximumvalues of 3.7 GPa, 651.5 MPa, and 10.89 MPa·m1/2, respectively. Analysis of fracture surface and crackpropagation paths indicated that crack deflection and crack bridging of the in situ precipitated Ti2AlC phasesobtained by decomposing Ti3AlC2 were the main reasons for the observed composite toughening.

High Temperature of Food and Beverage Intake Increases the Risk of Oesophageal Cancer in Xinjiang, China

Tang, Li,Xu, Fenglian,Zhang, Taotao,Lei, Jun,Binns, Colin William,Lee, Andy Ho-Won Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.9

Background: The north-western region of China has a high incidence of oesophageal cancer. This study aimed to investigate whether the intake of food and beverage at high temperature is associated with the risk of oesophageal cancer among adults residing in this remote part of China. Materials and Methods: A case-control study was undertaken in Urumqi and Shihezi, Xinjiang Uyghur Autonomous Region of China, between 2008 and 2009. Participants were 359 incident oesophageal cancer patients and 380 hospital-based controls. Information on temperature of food and beverage intake was obtained by face-to-face interview. Logistic regression analyses were performed to ascertain the association between intake temperature and the risk of oesophageal cancer. Results: The oesophageal cancer patients consumed foods and beverages at higher temperatures than controls, p<0.001. High temperature of tea, water and food intake appeared to increase the risk of oesophageal cancer by more than two-fold, with adjusted odds ratio (95% confidence intervals) of 2.86 (1.73-4.72), 2.82 (1.78-4.47) and 2.26 (1.49-3.45), respectively. Conclusions: Intake of food and beverage at high temperature was positively associated with the incidence of oesophageal cancer in north-western China.

Breakup dynamics of ferrofluid droplet in a microfluidic T-junction

Rui Ma,Taotao Fu,Qindan Zhang,Chunying Zhu,Youguang Ma,Huai Z. Li 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.54 No.-

This paper investigated the breakup dynamics of ferrofluid droplet in a microfluidic T-junction with the magnetic field. Droplet breakup types with permanent obstruction, part obstruction and without obstruction were observed. The droplet breakup processes with permanent and part obstruction could be divided into squeezing, transition and pinch-off stages. The minimum width of droplet neck could be scaled as power-law relationships with time for squeezing stage and with remaining time for the last two stages. The droplet breakup process without obstruction has only last two stages. The results show that the magnetic field could affect the dynamics of droplet breakup.

Effect of Plastic Deformation and Texture on Corrosion of Cold-Rolled AA6061 in NaCl Neutral Solution

Diaoyu Zhou,Taotao Li,Jing Fan 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.6

Effects of plastic deformation on the corrosion behaviors of AA6061 aluminum alloy have been investigated in this work. AA6061 was severely deformed by cold rolling processes and the corrosion behaviors were measured using electrochemicaltests in 3.5 wt% NaCl neutral solution. The microstructures were characterized by SEM combined with EDS. The resultsshowed that plastic deformation induced the decrease of average pitting potential and increase of corrosion rate of AA6061due to the number increase and size decrease of second-phase particles, which formed "small cathode-large anode" microbatterycorrosion mechanism with the aluminum alloy matrix. The influence of crystallographic texture on corrosion propertyis analyzed and a simple relation between average pitting corrosion coefficient and texture coefficient is built and supportedby experiments to elucidate the effects of plastic deformation on corrosion.

Fabrication and Characteristics of TiO2 Nanotubes on Hemispherical Diamond Films Using ZnO Nanorods as Template

Qiliang Wang,Qi Yu,Junsong Liu,Taotao Ai,Hongdong Li 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2015 NANO Vol.10 No.6

Zinc oxide (ZnO) nanorods (NRs) have been synthesized as a template to fabricate TiO2 nanotubes (TiNTs) on hemispherical diamond film by liquid-phase deposition (LPD) method. The process concerning the formation of TiNTs was analyzed. Based on the results of XRD and Raman spectroscopy, it is demonstrated that TiNTs was successfully obtained after removing ZnO NRs by chemical etching at room temperature. The TiNTs on hemispherical diamond film show higher performance photocatalysis, examined by the degradation of the reactive yellow 15(RY15) solution. The corresponding mechanism is discussed.

Effects of the resultant force due to two-phase density difference on droplet formation in a step-emulsification microfluidic device

Zhiwei Zhang,Mengyu Fan,Qianqiao Wang,Huaiyu Li,Chunying Zhu,Youguang Ma,Taotao Fu 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.110 No.-

This study focuses on the influence of the resultant force caused by the density difference of the twophases on the droplet generation process in a step-emulsification microfluidic device. Threedimensionalvisualization is used to observe the characteristics of droplet generation. According to thedifference in droplet generation form, it can be divided into drip generation mode and suspended generationmode. In the suspended generation mode, the droplets are more inclined to the formation process ofthe expansion of the ellipsoid, whose size in the horizontal direction is larger than the vertical direction;while in the drip generation mode, the shape of the droplet is opposite. The control stage of the dropletgeneration under various operating conditions is determined. As the viscosity of the dispersed phaseincreases, the control stage of the suspended generation mode is the necking stage, and the control stageof the drip generation mode changes from the first stage of three-dimensional expansion to the neckingstage. The model of the droplet generation is proposed by combining mechanical analysis and experimentaltesting data, and the droplet size prediction formula is thereby obtained.

Performance of Tunnel Feet-Lock Pipe (TFP) in Sharing Vertical Foundation Load

Lijun Chen,Jianxun Chen,Yao Li,Yanbin Luo,Yongjun Mu,Taotao Hu,Chuanwu Wang 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.3

During the tunnel construction in soft ground, the insufficient bearing capacity of tunnel foundation usually causes a series of settlement problems. Tunnel feet-lock pipe (TFP) has been widely used to take the vertical load acting at the foundation of a tunnel foot. However, the detailed bearing performance of TFP is still not clear, and there is a lack of quantitative research. In this paper, a simple analytical approach is adopted to evaluate the performance of the TFP, and the main parameters affecting the supporting performance of the TFP are analyzed. The results show that the ϕ42 − ϕ140 TFP with the angle of 10° can take 3.8% −40.4% of vertical load. TFP has an effective length of 1.7 m − 2.8 m, which is related to the relative stiffness between the TFP and the stratum. With the increase of the installation angle, the TFP shares more vertical load. This trend is more obvious when the angle of the TFP is greater than 20°. If the proportion coefficient of the subgrade reaction coefficient is doubled, the vertical load shared by the TFP can be increased by 34% − 38%. For every 10 cm increase in overbreak behind the steel rib, the vertical load shared by TFP is reduced by 16%.