http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Gradient folding metasurfaces with simultaneous phase and amplitude modulation
Zibin Lin,Weikai Xu,Wei Wang,Shasha Yuan 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.12
An elastic metasurface with a gradient index of functional units, namely gradient folding metasurface (GFMS), is proposed to simultaneously manipulate the transmission phase and amplitude of flexural waves. By varying the gradient index common ratio (CR) between each adjacent unit, the GFMS was found to cover an entire 2π span of phase shift. At the same time, the amplitude of the transmitted flexural wave can also be modulated. Based on the generalized Snell's law, two different cases of the wave focusing effect are realized, which illustrate CR dependent wave propagation mode from symmetric to asymmetric and verify the ability of the proposed metasurface to manipulate complete elastic wave through simultaneous phase and amplitude modulation. This study expands phase-amplitude modulation from acoustics to elastic waves and provides more degrees of freedom in elastic metasurface designing.
Fault diagnosis of rotating machine by isometric feature mapping
Yun Zhang,Benwei Li,Zibin Wang,Wen Wang,Lin Wang 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.11
Principal component analysis (PCA) and linear discriminate analysis (LDA) are well-known linear dimensionality reductions for fault classification. However, since they are linear methods, they perform not well for high-dimensional data that has the nonlinear geometric structure. As kernel extension of PCA, Kernel PCA is used for nonlinear fault classification. However, the performance of Kernel PCA largely depends on its kernel function which can only be empirically selected from finite candidates. Thus, a novel rotating machine fault diagnosis approach based on geometrically motivated nonlinear dimensionality reduction named isometric feature mapping (Isomap) is proposed. The approach can effectively extract the intrinsic nonlinear manifold features embedded in high-dimensional fault data sets. Experimental results with rotor and rolling bearing data show that the proposed approach overcomes the flaw of conventional fault pattern recognition approaches and obviously improves the fault classification performance.
Xiaoyu Li,Xianzhi Zhao,Wen Song,Zibin Tian,Lin Yang,Qinghui Niu,Qi Zhang,Man Xie,Bin Zhou,Yonghong Xu,Jun Wu,Cuiping Zhang 연세대학교의과대학 2018 Yonsei medical journal Vol.59 No.1
Purpose: This study was aimed to investigate the effect of pseudolaric acid B (PAB) on proliferation, invasion and epithelial-to-mesenchymal transition (EMT) in pancreatic cancer cells and to explore the possible mechanism. Materials and Methods: The pancreatic cancer cell line SW1990 was cultured and treated with PAB dose- and time-dependent manners. Cell proliferation and invasion ability were measured by MTT assay and Matrigel/Transwell test, respectively. Semi-quantitative real-time polymerase chain reaction and Western blotting were conducted to detect the expression of EMT markers and the key molecules. Finally, nude mice subcutaneous transplantation tumor model was used to confirm the therapy efficacy of PAB. Results: PAB could inhibit SW1990 cell proliferation and invasion in time- and dose-dependent manners. Vimentin, fibronectin, N-cadherin, Snail, Slug, YAP, TEAD1, and Survivin were down-regulated (p<0.01), while E-cadherin, caspase-9, MST1, and pYAP were up-regulated (p<0.05). Combined PAB and gemcitabine treatment markedly restricted the tumor growth compared with gencitabin or PAB alone groups. Conclusion: PAB could inhibit the proliferation and invasion ability of pancreatic cancer cells through activating Hippo-YAP pathway and inhibiting the process of EMT.