http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Qin Tang,Xiaoping Lin,Shengshi Zhao,Yi Niu,Heng Sun,Yun Dong 대한금속·재료학회 2020 METALS AND MATERIALS International Vol.26 No.4
Columnar-structured Mg97.27Zn2.54Y0.19alloy with the preferred growth direction of ⟨22̄45⟩ and ⟨12̄33⟩, andMg98.01Zn1.84Y0.13Zr0.03alloy with the preferred growth direction of ⟨11̄20⟩ were prepared using the directional solidificationtechnique and then tensile tested at 250–300 °C. The results showed that the Mg97.27Zn2.54Y0.19alloy with columnar dendriticstructure experienced a significant deformation strengthening period when stretched at 250 °C, and a typical dynamicrecrystallization stage at 300 °C, which were mainly accounted for its well-developed secondary dendrites, a large numberof branch-shaped second phases distributed in the longitudinal grain boundary, and less granular second phases existingin the crystal. While in the whole test temperature range (250–300 °C), the stress–strain curves of Mg98.01Zn1.84Y0.13Zr0.03alloys with cellular dendritic crystals showed a steady deformation state because of the second phases with strip distributingin the longitudinal grain boundary, which was induced by a balance between the deformation strengthening and the dynamicrecrystallization. Especially at 300 °C, this steady deformation state existed in the strain of 5.6%–36%. The good uniformplastic deformation was closely related to the small misorientations between columnar grains, the associated movement ofgrains by grain boundary slipping, and the less percentage of dynamically recrystallized grains which could do harm to theorientation continuity of the columnar crystals.
QIN HU,YING QI LIU,NING LI,CHUN CHENG,SHUIGANG XU,NING WANG,WEI QIN,BEN ZHONG TANG 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2013 NANO Vol.8 No.3
A general and reliable method has been developed to functionalize either the iron oxide or the silicon nanowires (NWs) with nickel–nitriloacetic acid (Ni–NTA) complex, which was manufactured to manipulate His-tagged proteins and enzymes. The Ni–NTA-functionalized sea-urchin-shaped α-Fe2O3 NWs exhibit the superior protein purification efficiency and excellent stability in the form of dry powder. Application of this new nanotechnology in biomedical research field has been explored. A glucose degradation bio-matrix was made via the Ni–NTA-modified silicon NW-chips, which were conjugated with an enzyme essential to glycolysis. The glucose level in a simulated blood solution was found to be reduced from 14.4 mM to 9 mM after incubating the hexokinase I-functionalized silicon NW-chips for 12 h. These results suggest a possible way to build up a medical device using enzymes functionalized NW-chips for the removal of excess blood glucose.
The Properties of Planck Galactic Cold Clumps in the L1495 Dark Cloud
Tang, Mengyao,Liu, Tie,Qin, Sheng-Li,Kim, Kee-Tae,Wu, Yuefang,Tatematsu, Ken’ichi,Yuan, Jinghua,Wang, Ke,Parsons, Harriet,Koch, Patrick M.,Sanhueza, Patricio,Ward-Thompson, D.,Tó,th, L. Viktor,S American Astronomical Society 2018 The Astrophysical journal Vol.856 No.2
Tang Xue-lin,Bian Li-yuan,Wang Fu-jun,Li Xiao-qin,Hao Man 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.6
A cavitation model with thermodynamic effects for cavitating flows in a diffuser-type centrifugal pump is developed based on the bubble two-phase flow model. The proposed cavitation model includes mass, momentum, and energy transportations according to the thermodynamic mechanism of cavitation. Numerical simulations are conducted inside the entire passage of the centrifugal pump by using the proposed cavitation model and the renormalization group-based k −ε turbulent model coupled with the energy transportation equation. By using the commercial computational fluid dynamics software FLUENT 6.3, we have shown that the predicted performance characteristics of the pump, as well as the pressure, vapor, and density distributions in the impeller, agree well with that calculated by the full cavitation model. Simulation results show that cavitation initially occurs slightly behind the inlet of the blade suction surface, i.e., the area with maximum vapor concentration and minimum pressure. The predicted temperature field shows that the reduction in temperature restrains the growth of cavitating bubbles. Therefore, the thermodynamic effect should be treated as a necessary factor in cavitation models. Comparison results validate the efficiency and accuracy of the numerical technique in simulating cavitation flows in centrifugal pumps.
Association of Urinary Cesium with Breast Cancer Risk
Qin, Ya-Chao,Tang, Lu-Ying,Su, Yi,Chen, Li-Juan,Su, Feng-Xi,Lin, Ying,Zhang, Ai-Hua,Ren, Ze-Fang Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.22
Background: The aim of this study is to examine the association of urinary cesium with breast cancer risk. Materials and Methods: We collected survey data and urine specimens from 240 women with incident invasive breast cancer before their treatment and 246 age-matched female controls between October 2009 and July 2010. Urinary concentrations of cesium were determined by inductively coupled plasma mass spectrometry. Interviews were conducted by face-to-face to obtain information on potential breast cancer risk factors. Logistic regression analysis was used to estimate the associations. Results: Creatinine-adjusted levels [median ($25^{th}$, $75^{th}$) ug/g] of cesium in cases and controls were 17.6 (13.1, 24.0) and 19.3 (15.3, 25.7), respectively. After adjustment for potential risk factors, women in the second and highest tertile of cesium showed a decreased risk of breast cancer in a dose-dependent manner as compared with those in the lowest tertile [ORs and 95% CIs: 0.75 (0.46-1.22) and 0.50 (0.30-0.82), respectively]. This decrease was more evident in women with ER positive or localized clinical stage in an exploratory stratification analysis. Conclusions: These findings suggest that cesium may have anticancer efficacy and urinary cesium has potential as a biomarker for breast cancer risk assessment.
Analysis on an improved resistance tuning type multi-frequency piezoelectric spherical transducer
Lei Qin,Jianjun Wang,Donghuan Liu,Lihua Tang,Gangbing Song 국제구조공학회 2019 Smart Structures and Systems, An International Jou Vol.24 No.4
The existing piezoelectric spherical transducers with fixed prescribed dynamic characteristics limit their application in scenarios with multi-frequency or frequency variation requirement. To address this issue, this work proposes an improved design of piezoelectric spherical transducers using the resistance tuning method. Two piezoceramic shells are the functional elements with one for actuation and the other for tuning through the variation of load resistance. The theoretical model of the proposed design is given based on our previous work. The effects of the resistance, the middle surface radius and the thickness of the epoxy adhesive layer on the dynamic characteristics of the transducer are explored by numerical analysis. The numerical results show that the multi-frequency characteristics of the transducer can be obtained by tuning the resistance, and its electromechanical coupling coefficient can be optimized by a matching resistance. The proposed design and derived theoretical solution are validated by comparing with the literature given special examples as well as an experimental study. The present study demonstrates the feasibility of using the proposed design to realize the multi-frequency characteristics, which is helpful to improve the performance of piezoelectric spherical transducers used in underwater acoustic detection, hydrophones, and the spherical smart aggregate (SSA) used in civil structural health monitoring, enhancing their operation at the multiple working frequencies to meet different application requirements.
Method of stress field and stability analysis of bedding rock slope considering excavation unloading
Hui Qin,Xiaotao Yin,Hua Tang,Xu Cheng,Hao Yuan 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.10
The stress state of a slope and its analytical solution are prerequisites for stability analysis. Currently, the limit equilibrium method cannot consider the stress state of slopes, and the solution of bedding slope stress remains in numerical simulations for a long time. In this paper, based on the theory of the elastic stress solution of the wedge top under a concentrated load, the analytical solution of the stress field was obtained using Matlab programming. Unloading stress analysis method (USAM) for determining the sliding surface of the bedding rock slope, safety factor (Fs), and reinforcement forces (Fr) were proposed. The USAM is compared with the Limit Equilibrium Method (LEM) and Finite Element Method (FEM) in terms of the Fs, Fr, sliding surface position, and sliding surface stress. The results show: 1) The analytical stress of the slope can be obtained quickly and conveniently using the USAM, while subsequent programming helps in faster completion of the stability evaluation of the bedding rock slope. Fs, Fr, sliding surface position, and sliding surface stress are all close to the results obtained by the FEM. 2) The USAM is more suitable for analyzing slopes when the angle between the slope surface and structural plane is greater than 20° (θ > 20o) and the slope angle is greater than 45o (β > 45o). 3) Through the analysis of specific engineering cases, the safety factor calculated by USAM are 0.06 and 0.02 larger than those obtained by LEM and FEM, respectively, and the required reinforcement force for the slope is closer to that obtained by FEM. The novel stress and stability analysis method allows for the rapid evaluation and optimal engineering design of bedding rock slope.