http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Self-Assembly and Tribological Properties of Carbon Nanotubes Film on Silicon Substrates
Zhiyong Sun,Xianhua Cheng 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2015 NANO Vol.10 No.7
Carbon nanotubes (CNTs) film was prepared on silicon (Si) substrate with a 3-aminopropyltriethoxysilane (APTES) film as the interlayer in a multistep self-assembly process. The formation and microstructure of the CNTs film were characterized by using scanning electron microscopy (SEM), water contact angles (WCAs) and X-ray photoelectron spectrometry (XPS). Tribological properties were evaluated with a UMT-2MT reciprocating friction tester. Results show that the CNTs were successfully assembled on Si substrates by chemical bonding between functional groups. CNTs film exhibited excellent friction reduction, high load-bearing capacity and antiwear ability. The friction coefficient was reduced drastically from 0.7 to 0.16, with markedly prolonged antiwear lifetime compared to bare Si substrates or APTES film. These superior tribological properties are attributable to the remarkable mechanical properties of CNTs and strong bond properties with the APTES film. CNTs film is thus expected to find wider application as high-performance lubricating film in micro/nanoelectromechanical systems (M/NEMS) in future.
Distributed stabilization control of rigid formations with prescribed orientation
Sun, Zhiyong,Park, Myoung-Chul,Anderson, Brian D.O.,Ahn, Hyo-Sung Elsevier 2017 Automatica Vol.78 No.-
<P><B>Abstract</B></P> <P>Most rigid formation controllers reported in the literature aim to only stabilize a rigid formation shape, while the formation orientation is not controlled. This paper studies the problem of controlling rigid formations with prescribed orientations in both 2-D and 3-D spaces. The proposed controllers involve the commonly-used gradient descent control for shape stabilization, and an additional term to control the directions of certain relative position vectors associated with certain chosen agents. In this control framework, we show the minimal number of agents which should have knowledge of a global coordinate system (2 agents for a 2-D rigid formation and 3 agents for a 3-D rigid formation), while all other agents do not require any global coordinate knowledge or any coordinate frame alignment to implement the proposed control. The exponential convergence to the desired rigid shape and formation orientation is also proved.</P>
A Novel Extreme Learning Machine based Denoising Algorithm
Zhiyong Fan,Quansen Sun,Feng Ruan,Kai Hu,Jin Wang 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.2
We introduce a fast and effective algorithm extreme learning machine (ELM) and apply it to image denoising. GA-ELM algorithm we proposed uses genetic algorithm(GA) to decide weights and bias in the ELM. It has better global optimal characteristics than traditional optimal ELM algorithm. In this paper, we used GA-ELM to do image denosing researching work. Firstly, this paper uses training samples to train GA-ELM as the noise detector. Then, we utilize the well-trained GA-ELM to recognize noise pixels in target image. And at last, an adaptive weighted average algorithm is used to recover noise pixels recognized by GA-ELM. Experiment data shows that this algorithm has better performance than other denosing algorithm.
Zhiyong Chen,Jianjun Lu,Xuping Li,Xuting Jin,Lijuan Shi,Miaoqing Liu,Zhilin Sun 한국고분자학회 2015 Macromolecular Research Vol.23 No.9
A novel 1,10-phenanthroline-functionalized polyimide (CMPI-Phen) was prepared as polymer matrix by the nucleophilic substitution reaction between chloromethylated polyimide (CMPI) and 5-amino-1,10-phenanthroline (NH2-Phen). Then, two kinds of luminescent materials of 1,10-phenanthroline-functionalized polyimide containing Eu(III) complexes, were obtained by two different methods. Their structures and properties were characterized by Fourier transform infrared (FTIR) spectroscopy, 1H nuclear magnetic resonance (NMR) spectroscopy, elemental analysis, inductively coupled plasma (ICP), gel permeation chromatography (GPC), thermogravimetric analysis (TGA), X-ray diffraction (XRD), luminescence spectrometry, and luminescence decay analysis. Investigations revealed that both the CMPI-Phen-Eu(III) and CMPI-Phen-Eu(TTA)3 display highly efficient red emissions, suggesting their potential application as luminescent materials. However, compared with CMPI-Phen-Eu(III), CMPI-Phen-Eu(TTA)3, where TTA stands for thenoyltrifluoroacetone, exhibits more excellent and stable fluorescence intensity and longer luminescence lifetime (134.30 μs). The weight-average molecular weights of CMPI-Phen-Eu(III) and CMPI-Phen- Eu(TTA)3 are 2.40×104 and 3.11×104, respectively. The Eu contents of CMPI-Phen-Eu(TTA)3 and CMPI-Phen-Eu(III) were measured by ICP to be 7.00% and 5.92%, respectively. TGA demonstrated that both CMPI-Phen-Eu(III) and CMPI-Phen-Eu(TTA)3 have high thermal stability and their 5% loss weight temperatures were 356 and 280 oC, respectively. Moreover, both CMPI-Phen-Eu(III) and CMPI-Phen-Eu(TTA)3 were soluble in polar solvents such as dimethylformamide (DMF), dimethylacetamide (DMAc), 1-methyl-2-pyrrolidone (NMP), and dimethylsulfoxide (DMSO) under heating conditions, and could be easily cast into tough thin films.
Xiaoyu Sun,Xiuting Wei,Zhiyong Li,Deda Lou,Yongqi Wang,Hanqing Liu 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.22 No.7
High precision laser cutting with minimal post-treatment is needed in the manufacturing of nitinol cardiovascular stents. This paper carries out a series of cutting experiments of nitinol cardiovascular stents by wet fiber laser cutting to understand the basic process characteristics and to investigate the influences of process parameters (laser power, cutting speed, pulse width, frequency) upon the surface integrity (surface topography, dross, surface roughness, HAZ, recast layer, subsurface nanohardness, surface chemical composition). The univariate analysis was used to analyze and explain the influence that rules of process parameters had upon the surface integrity. The experiment results showed that the effects of process parameters on surface integrity were regular, with the optimal single-factor parameters obtained. Moreover, the removal mechanism of the nitinol material was also revealed. This study is of great significance for the medical industry in improve the cutting quality of cardiovascular stents.
Flatbands and Emergent Ferromagnetic Ordering in Fe3Sn2 Kagome Lattices
Lin, Zhiyong,Choi, Jin-Ho,Zhang, Qiang,Qin, Wei,Yi, Seho,Wang, Pengdong,Li, Lin,Wang, Yifan,Zhang, Hui,Sun, Zhe,Wei, Laiming,Zhang, Shengbai,Guo, Tengfei,Lu, Qingyou,Cho, Jun-Hyung,Zeng, Changgan,Zhan American Physical Society 2018 Physical Review Letters Vol.121 No.9
Effect of electron irradiation on electronic structure of Ni41Co6Mn43Sn10 alloys
Sibo Sun,Jun Zhang,Zhiyong Gao,Wei Cai 대한금속·재료학회 2024 ELECTRONIC MATERIALS LETTERS Vol.20 No.1
Eff ect of electron irradiation on electronic structure of Ni 41 Co 6 Mn 43 Sn 10 alloys were investigatedby X-ray absorption fi ne structure, X-ray magnetic circular dichroism spectrometry and Mössbauerspectrometry. The local coordination environment of magnetic element signifi cant changes after electronirradiation, the change in the peak intensity of the Co L 3 edge is opposite to the Ni/Mn element,indicating that there is an electronic exchange between them. The crystal fi eld symmetry is broken, thehyperfi ne fi eld H in of the Ni 41 Co 6 Mn 43 Sn 10 alloy increases from 8.80 to 9.06 T. Meanwhile, the spinmagnetic moment of the Mn atom is signifi cantly increased after electron irradiation.