http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Chuan Liu,Jia-bin Shen,Chang-hua Lin,Jian-fei Wang,Jian-xin Wang 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.5
Ultrasonic impact treatment (UIT) was carried out on three specimens with different strengths and, to measure the subsurface stress distribution of the specimens, the layer-by-layer removal x-ray diffraction method was applied. The stress redistribution due to material removal was corrected by finite element analysis. The effect of material strength on the after-UIT subsurface stress was investigated. The results show that the UIT can cause a compressive stress layer with a depth of over 2.5 mm for specimens with different strengths, while the material strength has no significant effect on the depth of UIT-induced stress. The UIT-induced peak compressive stresses in the three specimens exceed the material yield strength, appearing at the depth of 0.2 mm beneath the surface and increasing with the increase of material yield strength. The ratio of UIT-induced peak compressive stress magnitude to material yield strength decreases with the increase of material yield strength.
Rock-breaking analysis model of new drill bit with tornado-like bottomhole model
Jia-lin Tian,Chang-fu Yuan,Lin Yang,Chuan-hong Fu,Gang Liu,Zhi Yang,Chun-ming Wu 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.4
For improving the rock-breaking efficiency of oil and gas drill bits, a new drill bit is presented with tornado-like bottomhole model(named swirling cutting bit). The new drill bit cutter breaks rock with shocking and cutting effect during the drilling process, and theelements on largest ring cross the borehole center with high speed. It can effectively improve the center rock-breaking efficiency. Meanwhile,for all cutters on different rings breaking rock at the same time, it can optimize the rock-breaking volume of each element andimprove the bit service life. To analyze the interaction features between cutters and rock, the position equations are established by thecylindrical coordinates and complex movement principles, and then the velocity and acceleration equations can be obtained. Based on thenumerical example results, this paper analyzes the bottomhole model, the contact section, and the distribution features of velocities andaccelerations on different rings. By analyzing the acceleration results, we can study the failure mechanism of cutters. At the same time,lab experiments test the bottomhole model and rock-breaking features, and it verifies the accuracy of calculation method and equations. Moreover, the analysis method and models are also applicable to other types of bits or composite bits, and the inputting parameters needcorresponding adjustment for different type of bits.
Optical Characters Measurement and Simulation of 2D Cross Grating Microstructures of Butterfly Wings
Wang Zhang,Di Zhang,Wei-Xin Chen,Jia-Jun Gu,Qin-Lei Liu,Shen-Ming Zhu,Hui-Lan Su,Chuan-Liang Feng,문원진 한국정밀공학회 2012 International Journal of Precision Engineering and Vol. No.
In this paper, the reflectance of the butterfly wings are measured by using the microspectrophotometer as the optical character with the reflectance on several scales on the wings. Reflectance spectra from different wing scale zones with the same color are dramatically different. And it suggests that the tiny structural difference has the great influence on the reflectance property. In addition, the microstructures of the butterfly wings can be simplified to a 2D crossing grating. By simulating a two-dimensional model using rigorous coupled-wave analysis technique, the optical properties of the butterfly wings were investigated. The simulation results depend strongly on the structural parameters and refractive index. The research will reveal the mechanisms of the structural color of 2D crossing grating butterfly wings.
3’’-Hydroxyamentoflavone and Its 7-O-Methyl Ether, Two New Biflavonoids fromAristolochia contorta
Ye-Gao Chen,Li-Li Yu,Rong Huang,Jia-Chuan Liu,Yu-Ping Lv,Yong Zhao 대한약학회 2005 Archives of Pharmacal Research Vol.28 No.11
Two new biflavonoids, 3’’-hydroxyamentoflavone-7-O-methyl ether (1) and 3’’-hydroxyamentoflavone (2), were isolated from the fruits of Aristolochia contorta Bge. Their structures were elucidated by HR-ESI-MS, 1D-, and 2D-NMR spectroscopy.
Optical Characters Measurement and Simulation of 2D Cross Grating Microstructures of Butterfly Wings
Zhang, Wang,Zhang, Di,Chen, Wei-Xin,Gu, Jia-Jun,Liu, Qin-Lei,Zhu, Shen-Ming,Su, Hui-Lan,Feng, Chuan-Liang,Moon, Won-Jin 한국정밀공학회 2012 International Journal of Precision Engineering and Vol.13 No.9
In this paper, the reflectance of the butterfly wings are measured by using the microspectrophotometer as the optical character with the reflectance on several scales on the wings. Reflectance spectra from different wing scale zones with the same color are dramatically different. And it suggests that the tiny structural difference has the great influence on the reflectance property. In addition, the microstructures of the butterfly wings can be simplified to a 2D crossing grating. By simulating a two-dimensional model using rigorous coupled-wave analysis technique, the optical properties of the butterfly wings were investigated. The simulation results depend strongly on the structural parameters and refractive index. The research will reveal the mechanisms of the structural color of 2D crossing grating butterfly wings.
3'-Hydroxyamentoflavone and Its 7-O-Methyl Ether, Two New Biflavonoids from Aristolochia contorta
Chen Ye-Gao,Yu Li-Li,Huang Rang,Liu Jia-Chuan,Lv Yu-Ping,Zhao Yang The Pharmaceutical Society of Korea 2005 Archives of Pharmacal Research Vol.28 No.11
Two new biflavonoids, 3'-hydroxyamentoflavone-7-O-methyl ether (1) and 3'-hydroxyamentoflavone (2), were isolated from the fruits of Aristolochia contorta Bge. Their structures were elucidated by HR-ESI-MS, 1D-, and 2D-NMR spectroscopy.
Yu Jun Wong,Chen Zhaojin,Guilia Tosetti,Elisabetta Degasperi,Sanchit Sharma,Samagra Agarwal,Liu Chuan,Chan Yiong Huak,Li Jia,Qi Xiaolong,Anoop Saraya,Massimo Primignani 대한간학회 2023 Clinical and Molecular Hepatology(대한간학회지) Vol.29 No.1
Background/Aims: The utility of Baveno-VII criteria of clinically significant portal hypertension (CSPH) to predict decompensation in compensated advanced chronic liver disease (cACLD) patient needs validation. We aim to validate the performance of CSPH criteria to predict the risk of decompensation in an international real-world cohort of cACLD patients. Methods: cACLD patients were stratified into three categories (CSPH excluded, grey zone, and CSPH). The risks of decompensation across different CSPH categories were estimated using competing risk regression for clustered data, with death and hepatocellular carcinoma as competing events. The performance of “treating definite CSPH” strategy to prevent decompensation using non-selective beta-blocker (NSBB) was compared against other strategies in decision curve analysis. Results: One thousand one hundred fifty-nine cACLD patients (36.8% had CSPH) were included; 7.2% experienced decompensation over a median follow-up of 40 months. Non-invasive assessment of CSPH predicts a 5-fold higher risk of liver decompensation in cACLD patients (subdistribution hazard ratio, 5.5; 95% confidence interval, 4.0–7.4). “Probable CSPH” is suboptimal to predict decompensation risk in cACLD patients. CSPH exclusion criteria reliably exclude cACLD patients at risk of decompensation, regardless of etiology. Among the grey zone, the decompensation risk was negligible among viral-related cACLD, but was substantially higher among the non-viral cACLD group. Decision curve analysis showed that “treating definite CSPH” strategy is superior to “treating all varices” or “treating probable CSPH” strategy to prevent decompensation using NSBB. Conclusions: Non-invasive assessment of CSPH may stratify decompensation risk and the need for NSBB in cACLD patients.
A Novel Distributed Equivalent Circuit Model for Single-Core Cables
Li Rui-Fang,Hu Hao,Cao Xiao-Bin,Li Zhong-Mei,Li Jun-Hao,Zhu Chuan-Lin,Liu Le-Jia 대한전기학회 2024 Journal of Electrical Engineering & Technology Vol.19 No.1
The number of cables used for urban power supply increases rapidly. The sheath current in these cables, which is generated via induction, produces a current loss. When the situation is serious, the ground lead and the middle connector of the cable will be burned. In this paper, the existing single-core cable equivalent circuit model is used to calculate the sheath current of a 3-phase cable under the condition of non-transposition and cross connection. By comparing the calculated results with the simulation and the experimental results, it is found that the current distribution law for the sheath, which was obtained using the existing model, difers substantially from both the simulation and actual measurements. The error reason of the existing model is revealed, and it is found that the magnitude and phase of the current in the metal sheath of the cable varies with the position under the combined efect of distributed capacitances in the cable and the core-current fux, especially for a 3-phase cross connection, each section of the cable does not meet Kirchhof’s laws, but the sheath electric current in the existing models are considered equal everywhere. Therefore, a novel cable equivalent model is proposed in this paper, which is based on a distributed circuit, and an equation to calculate the sheath current is derived. The model presented in this paper corrects the problems of the existing model, which can be applied to power system, subway, high-speed rail, and any application of single-core cables.