Sensitive parameters’ optimization of the permanent magnet supporting mechanism

Yongguang Liu,Xiaohui Gao,Yixuan Wang,Xiaowei Yang 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.7

The fast development of the ultra-high speed vertical rotor promotes the study and exploration for the supporting mechanism. It hasbecome the focus of research that how to improve the speed and overcome the vibration when the rotors pass through the low-order criticalfrequencies. This paper introduces a kind of permanent magnet (PM) supporting mechanism and describes an optimization method ofits sensitive parameters, which can make the vertical rotor system reach 80000 r/min smoothly. Firstly we find the sensitive parametersthrough analyzing the rotor’s features in the process of achieving high-speed, then, study these sensitive parameters and summarize theregularities with the method of combining the experiment and the finite element method (FEM), at last, achieve the optimization methodof these parameters. That will not only get a stable effect of raising speed and shorten the debugging time greatly, but also promote theextensive application of the PM supporting mechanism in the ultra-high speed vertical rotors.

Antagonism of tomato spotted wilt virus against tomato yellow leaf curl virus in Nicotiana benthamiana detected by transcriptome analysis

Qiao Ning,Liu Yongguang,Liu Jie,Zhang Dezhen,Chi Wenjuan,Li Jintang,Zhu Xiaoping,Liu Hongmei,Li Fajun 한국유전학회 2023 Genes & Genomics Vol.45 No.1

Background Tomato spot wilt virus (TSWV) and tomato yellow leaf curl virus (TYLCV) are highly harmful viruses in agricultural production, which can cause serious economic losses to crops and even devastating consequences for vegetable yield in some countries and regions. Although the two viruses belong to different families and have different transmission vectors, they share most hosts. Objective This study aimed to examine the transcriptomic expression of single and mixed inoculations of TSWV and TYLCV, leading to antagonism using high-throughput RNA sequencing. Methods We confirmed the single and mixed infections of these viruses in Nicotiana benthamiana (N. benthamiana) by artificial inoculation. And the expression changes of related genes and their biological functions and pathways during the mixed infection of TSWV and TYLCV were analyzed by comparative transcriptome. Results Basically, similar symptoms were observed in the plants singly infected with TSWV and co-infected with TYLCV; the symptoms of TYLCV in the co-infected plants were not obvious compared with single TYLCV infections. When inoculated with TYLCV, the accumulation of the virus significantly reduced in single and mixed infections with TSWV; the TSWV accumulated slightly less in co-infection with TYLCV, whereas this reduction was much smaller than that of TYLCV. The results suggested that TSWV had an antagonistic effect on the accumulation of TYLCV in N. benthamiana. It mainly focused on the changes in unique differentially expressed genes (DEGs) caused by the co-infection of TSWV and TYLCV. The eight pathways enriched by upregulated DEGs mainly included amino acid biosynthesis, citrate cycle (or tricarboxylic acid cycle, TCA cycle), and so on. However, only pentose phosphate pathway (PPP) and peptidoglycan biosynthesis could be downregulated in the Kyoto Encyclopedia of Genes and Genomes pathway in which peptidoglycan biosynthesis was involved in upregulated and downregulated pathways. Conclusions The antagonistic effect of TSWV on TYLCV in N.benthamiana and the change trends and specific pathways of DEGs in this process were found. Our study provided new insights into the host regulation and competition between viruses in response to TSWV and TYLCV mixed infection.

Biosynthetic Pathway for Poly(3-Hydroxypropionate) in Recombinant Escherichia coli

Qi Wang,Changshui Liu,Mo Xian,Yongguang Zhang,Guang Zhao 한국미생물학회 2012 The journal of microbiology Vol.50 No.4

Poly(3-hydroxypropionate) (P3HP) is a biodegradable and biocompatible thermoplastic. In this study, we engineered a P3HP biosynthetic pathway in recombinant Escherichia coli. The genes for malonyl-CoA reductase (mcr, from Chloroflexus aurantiacus), propionyl-CoA synthetase (prpE, from E. coli), and polyhydroxyalkanoate synthase (phaC1, from Ralstonia eutropha) were cloned and expressed in E. coli. The E. coli genes accABCD encoding acetyl-CoA carboxylase were used to channel the carbon into the P3HP pathway. Using glucose as a sole carbon source, the cell yield and P3HP content were 1.32 g/L and 0.98% (wt/wt [cell dry weight]), respectively. Although the yield is relatively low,our study shows the feasibility of engineering a P3HP biosynthetic pathway using a structurally unrelated carbon source in bacteria.

A modified adaptive filtering algorithm with online secondary path identification used for suppressing gearbox vibration

Weijin Gao,Liang Wang,Yongguang Liu 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.11

We determined the actuator location based on the dynamic modal of gear shaft, and analyzed the feasibility of a modified filtered-x least mean square algorithm with online secondary path identification. The proposed adaptive controller is designed to drive the actuators for preventing the vibration caused by gear backlash from a gear pair passing to the external gear housing structure. For the vital identification system, a changed identification input with error energy is presented to reduce the impact of additive random noise on the whole system. To ensure a realistic assessment of the proposed control strategy, numerical studies were implemented for a gearbox used by NASA-GRC. The simulation results validate the efficiency of the proposed approach through promising vibration control results that will guide future experimental work.

Facile Synthesis of CdTe Nanorods from the Growth of Te Nanorods

Xu, Weiwei,Niu, Jinzhong,Zheng, Shuang,Tian, Guimin,Wu, Xinghui,Cheng, Yongguang,Hu, Xiaoyang,Liu, Shuaishuai,Hao, Haoshan Korean Chemical Society 2017 대한화학회지 Vol.61 No.4

One-dimensional CdTe nanorods (NRs) are obtained by the reaction of various Cd precursors with single crystalline Te nanorod templates, which are pre-synthesized from Te precursors by a simple and reproducible solvothermal method. Throughout the process, the diffraction intensity of different crystal facets of single crystalline Te NRs varied with reaction times. Finally, by alloying Cd ions along the axial direction of Te NRs, polycrystalline cubic phase CdTe NRs with diameters of 80-150 nm and length up to $1.2-2.4{\mu}m$ are obtained. The nucleation and growth processes of Te and CdTe NRs are discussed in details, and their properties are characterized by XRD, SEM, TEM, Raman scattering, and UV-vis absorption spectra. It was found that the key elements of synthesizing CdTe NRs such as reaction temperatures and Cd sources will strongly influence the final shape of CdTe NRs.

Active vibration control based on modal controller considering structure-actuator interaction

Jinjun Jiang,Weijin Gao,Liang Wang,Zhaohua Teng,Yongguang Liu 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.8

Active vibration control to suppress structural vibration of the flexible structure is investigated based on a new control strategy considering structure-actuator interaction. The experimental system consists of a clamped-free rectangular plate, a controller based on modal control switching, and a magnetostrictive actuator utilized for suppressing the vibrations induced by external excitation. For the flexible structure, its deformation caused by the external actuator will affect the active control effect. Thus interaction between structure and actuator is considered, and the interaction model based on magnetomechanical coupling is incorporated into the control system. Vibration reduction strategy has been performed resorting to the actuator in optimal position to suppress the specified modes using LQR (linear quadratic regulator) based on modal control switching. The experimental results demonstrate the effectiveness of the proposed methodology. Considering structure-actuator interaction (SAI) is a key procedure in controller design especially for flexible structures.