Fabrication of Scale Gratings for Surface Encoders by Using Laser Interference Lithography with 405 nm Laser Diodes

Xinghui Li,Yuki Shimizu,So Ito,Wei Gao 한국정밀공학회 2013 International Journal of Precision Engineering and Vol. No.

This paper presents a cost-effective fabrication method of grating structures with a period of sub-μm for surface encoders. By employing an inexpensive and compact blue laser diode, which has a wavelength of 405 nm and is used in Blu-ray disc drives, a Lloyd’s mirror interferometer has been developed to carry out laser interference lithography for the fabrication of grating structures. Experimental results showed that the developed fabrication system is capable of fabricating grating structures with a pitch of 570 nm. The relative pitch deviation is confirmed to be approximately 1%, which meets the requirement for the scale grating used in a surface encoder. The influence of the limited coherence length of the laser diode on the fabrication area of the grating structures has also been investigated. To expand the fabrication area of the grating structure, a laser source, which has a wavelength of 405 nm and a longer coherence length with a mode selection cavity, is employed in the fabrication system. It has been verified by experiments that the fabrication area of the sub-μm periodic grating structures can be expanded to 300 mm2 with the laser source.

General Vacuum Electronics

Jinjun Feng,Xinghui Li,Jiannan Hu,Jun Cai 한국전자파학회JEES 2020 Journal of Electromagnetic Engineering and Science Vol.20 No.1

The electron devices in which electrons do not collide with other particles or in which the collision probability is very small in the transport process can be theoretically regarded as general vacuum electron devices. General vacuum electron devices include microfabricated vacuum nano-electronic devices, which can work in atmosphere, and some solid-state electron devices with nanoscale channel for electrons whose material characteristics are close to those of vacuum channels. Vacuum nano-electron devices (e.g., nanotriodes) are expected to be the fundamental elements for high-speed, radiation-resistant large-scale vacuum integrated circuits. The solid-state electron devices with spin semiconductor materials, multiferroics or topological crystal insulators are quite different from traditional semiconductor devices and are expected to operate under novel principles. Understanding vacuum electron devices from a microcosmic perspective and understanding solid-state electron devices from a vacuum perspective will promote a union of vacuum electronics and microelectronics, as well as the formation and development of general vacuum electronics.

Signal Processing and Artificial Intelligence for Dual-Detection Confocal Probes

Ryo Sato,Xinghui Li,Andreas Fischer,Liang-Chia Chen,Chong Cheng,Rintaro Shimomura,Wei Gao 한국정밀공학회 2024 International Journal of Precision Engineering and Vol.25 No.1

The confocal probe is one of the most well-used optical sensors for displacement/position measurement as well as for mapping of three-dimensional microstructured surfaces and internal structures. A dual-detection configuration employing two detectors is often used in the state-of-the-art confocal probes to achieve wider measurement ranges, higher resolutions, better accuracies and faster measurement speeds. In this paper, the motivation and benefits for development and employment of the dual-detection confocal probes, as well as the investigation of the detector positions, are first presented. The signal processing methods associated with the dual-detection confocal probes are then categorized into the difference-type and the ratio-type, followed by descriptions on the features of each method. Finally, signal processing based on artificial intelligence and machine learning for the confocal probes are presented.

A novel hybrid compound fault pattern identification method for gearbox based on NIC, MFDFA and WOASVM

Xin Zhang,Jianmin Zhao,Xinghui Zhang,Xianglong Ni,Haiping Li,Fucheng Sun 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.3

Gearbox compound fault pattern recognition is challenging because of its complexity and non-stationarity of the vibration signal. In this study is proposed a novel hybrid method based on narrow band interference canceller (NIC), multifractal detrended fluctuation analysis (MFDFA) and support vector machine optimized by whale optimization algorithm (WOASVM) for compound fault pattern recognition of gearbox. Specifically, the raw signal is processed by NIC to filter the deterministic signal which interferes with the fault signal, and then the multifractal features are extracted from the residual signal via MFDFA. Finally, the compound fault pattern is identified via WOASVM. Compound fault experiments of a gearbox under fixed condition and variable condition were done to evaluate the performance of the proposed method. The results show that the proposed method can effectively identify the compound faults and it outperforms other methods mentioned in this paper.

3D-monoclinic M–BTC MOF (M = Mn, Co, Ni) as highly efficient catalysts for chemical fixation of CO2 into cyclic carbonates

Yuanfeng Wu,Xianghai Song,Shuai Li,Jiahui Zhang,Xinghui Yang,Pengxin Shen,Lijing Gao,Ruiping Wei,Jin Zhang,Guomin Xiao 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.58 No.-

[(CH3)2NH2][M3(BTC)(HCOO)4(H2O)].H2O (M–BTC, M = Mn, Ni, Co) were prepared under hydrothermal conditions and used as highly efficient catalysts for cycloaddition of CO2 with epichlorohydrin (ECH). The microstructure and physicochemical properties of the compounds were determined by PXRD, FT-IR, XPS, N2-adsorption, TG–DSC, NH3–TPD and CO2–TPD. 98.01% conversion of ECH and 96.05% selectivity to chloropropene carbonate was obtained over the Mn–BTC under the optimized reaction conditions (105 °C, 3.0 MPa, 9 h, 1.5 wt.% of ECH). Besides, the recyclability result exhibited the Mn–BTC compound can be utilized as least three times with a slight reduction in its catalytic ability. In addition, cycloaddition of CO2 with other epoxides and DFT calculation were also performed. The result exhibited the yield followed the order: ECH > 1, 2-epoxybutane > propene oxide > Allyl glycidyl ether, which was mainly determined by the energy of reaction.

Overexpression of a Camellia sinensis DREB transcription factor gene (CsDREB) increases salt and drought tolerance in transgenic Arabidopsis thaliana

Mingle Wang,Jing Zhuang,Zhongwei Zou,Qinghui Li,Huahong Xin,Xinghui Li 한국식물학회 2017 Journal of Plant Biology Vol.60 No.5

Dehydration-responsive element-binding protein(DREB) transcription factors play key roles in plant stresssignal transduction pathways. We herein describe the functionsof a Camellia sinensis DREB transcription factor (CsDREB)in response to abiotic stress. Subcellular localization analysesindicated that the CsDREB localizes to the nucleus. CsDREBexpression in C. sinensis leaves was induced by heat, cold,drought, high salinity, H2O2, and exogenous abscisic acid(ABA). Additionally, CsDREB showed no transcriptionalactivation in Saccharomyces cerevisiae. Transgenic Arabidopsisthaliana plants overexpressing CsDREB exhibited enhancedtolerance to salt and drought stresses. The overexpression ofCsDREB in A. thaliana plants resulted in the up-regulatedexpression of ABA-dependent stress-induced genes (i.e.,AtRD29B, AtRAB18, AtABI1, and AtABI2) and ABAindependentstress-induced genes (i.e., AtCOR15a andAtRD29A). Furthermore, an analysis of the CsDREB promotersequence revealed the presence of several abiotic and bioticstress-related motifs, along with the developmental stageandtissue-specific elements. An examination of thetransient expression of the CsDREB promoter in Nicotianabenthamiana leaves revealed that the promoter is highlyresponsive to ABA and methyl jasmonate. Collectively, theseresults suggest that CsDREB may increase plant tolerance tosalt and drought stresses via both ABA-dependent and ABAindependentpathways.

Clinical Characteristics and Impact of Diabetes Mellitus on Outcomes in Patients with Nonvalvular Atrial Fibrillation

Bi Huang,양안민,Jun Zhu,Yan Liang,Han Zhang,Li Tian,Xinghui Shao,Juan Wang 연세대학교의과대학 2015 Yonsei medical journal Vol.56 No.1

Purpose: Studies have shown that diabetes mellitus (DM) is a risk factor for cardiovasculardisease, including atrial fibrillation (AF); however, the clinical characteristicsand prognostic impact of DM in patients with nonvalvular AF have not been well understood in China. Materials and Methods: Included were 1644 consecutive patients with nonvalvular AF. Endpoints included all-cause mortality, cardiovascular mortality, stroke, major bleeding, and combined endpoint events (CEE) during a 1-year follow-up. Results: The prevalence of DM was 16.8% in nonvalvular AF patients. Compared with non-diabetic AF patients, diabetic AF patientswere older and tended to coexist with other cardiovascular diseases. Most patients with DM (93.5%) were eligible for anticoagulation, as determined by CHADS2 scores. However, only 11.2% of patients received anticoagulation. Duringa 1-year follow-up, the all-cause mortality and CEE rate in the DM group were significantly higher than those of the non-DM group, while the incidence of stroke was comparable. After multivariate adjustments, DM was still an independent risk factor for 1-year all-cause mortality [hazard ratio (HR)=1.558; 95% confidence interval(CI) 1.126‒2.156; p=0.007], cardiovascular mortality (HR=1.615; 95% CI 1.052‒2.479; p=0.028), and CEE (HR=1.523; 95% CI 1.098‒2.112; p=0.012), yet not for stroke (HR=1.119; 95% CI 0.724‒1.728; p=0.614). Conclusion: DM is a common morbidity coexisting with nonvalvular AF and is associated with an increasedrisk of 1-year all-cause mortality, cardiovascular mortality, and CEE. However, no increased risk of stroke was found during a 1-year follow-up in patientswith AF and DM.