Preparation and Microwave Absorption Properties of M-type Ferrite Nanoparticles Composites

Guozhu Shen,Zheng Xu 한국자기학회 2008 한국자기학회 학술연구발표회 논문개요집 Vol.- No.-

Nonlinear Model Predictive Path Tracking Control for Autonomous Vehicles Based on Orthogonal Collocation Method

Guozhu Zhu,Hao Jie,Weirong Hong 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.1

Autonomous vehicles have gained popularity over the past few years. In this paper, we present a nonlinear model predictive control approach for autonomous vehicles to follow the desired path in various driving environments. Instead of utilizing Euler discretization method which is common in the literature related to MPC-based path tracking, our formulated nonlinear optimal control problem is discretized by orthogonal collocation method for higher tracking accuracy. The presented methodology considers the maximization of longitudinal progression along the reference path, target accurate tracking and comfortable ride. The single-track dynamic model combined with a simplified but effective enough tire model is used. Then the proposed controller is tested and compared with the controller based on Euler discretization in two simulation scenarios to validate its effectiveness. The simulation results demonstrate the integration of longitudinal and lateral motion control of our proposed controller and the better performance in tracking accuracy. Real-time performance of the proposed controller is also discussed.

Effect of Ru crystal phase on the catalytic activity of hydrolytic dehydrogenation of ammonia borane

Chen, Guozhu,Wang, Ruyue,Zhao, Wei,Kang, Baotao,Gao, Daowei,Li, Cuncheng,Lee, Jin Yong Elsevier 2018 Journal of Power Sources Vol.396 No.-

<P><B>Abstract</B></P> <P>Ruthenium (Ru) is one of the most attractive catalysts in the hydrolytic dehygrogenation of ammonia borane. So far, the employed Ru-based catalysts are mainly focusing on hexagonal close packed structured Ru. In this work, we study the crystal phase effect of Ru on the hydrolytic dehygrogenation of ammonia borane, using face-centered cubic structured and hexagonal close packed structured Ru nanoparticles supported on γ-Al<SUB>2</SUB>O<SUB>3</SUB>. The results show that the catalytic activity is different even these two kinds of Ru nanoparticles hold similar size. Impressively, with the Ru particle size change, the variation trend of activity is opposite for face-centered cubic and hexagonal close packed structured Ru/γ-Al<SUB>2</SUB>O<SUB>3</SUB>. Finally, some possible reasons for their difference are proposed based on density functional theory calculations.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The crystal phase effect of Ru on the hydrolysis of ammonia borane was studied. </LI> <LI> The <I>hcp</I> Ru/γ-Al<SUB>2</SUB>O<SUB>3</SUB> exhibits higher activity than that of <I>fcc</I> Ru with similar Ru size. </LI> <LI> The variation trend of activity is opposite with the <I>fcc</I> and <I>hcp</I> Ru size change. </LI> <LI> DFT was used to understand the activity difference between <I>fcc</I> and <I>hcp</I> Ru. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Characterization of the Arabidopsis At5-MMP Matrix Metalloproteinase

Tang Guozhu,Wu Shuchi,Zhao Bingyu,Flinn Barry S. 한국식물학회 2022 Journal of Plant Biology Vol.65 No.6

The plant extracellular matrix (ECM) represents the continuum between the plasma membrane and the apoplast, and undergoes significant modifications during plant growth, development and stress responses. While matrix metalloproteinases (MMPs) are significant proteolytic modulators of the vertebrate ECM, they remain poorly understood in plant biology. Of the five Arabidopsis thaliana MMPs, At5-MMP is the most constitutively expressed and was chosen for further characterization. Autoactivation of recombinant At5-MMP generated a functional metalloproteinase which exhibited maximum proteolytic activity at pH 7.5, and a broad level of activity into the basic range. Furthermore, an E to A mutation within the HEIGH portion of the At5-MMP catalytic domain abolished proteolytic activity. Using GFP-tagged At5-MMP variants expressed in Nicotiana benthamiana, the predicted signal peptide was required for targeting to the cell periphery, and deletion of this peptide resulted in intracellular, localized At5-MMP accumulation. Using a generic MMP cleavage PXG(L/I) peptide sequence, the predicted Arabidopsis extracellular proteome was screened for potential candidate MMP substrates. The extracellular domain of one candidate, WAK1, was expressed as a recombinant protein and shown to be cleaved internally at specific sites by At5-MMP in vitro. These same cleavage sites were identified using mammalian MMP cleavage prediction software.

Status and Prospects of Farm Mechanization in China

Hua Guozhu 한국농업기계학회 1993 ICAMPE 요약집 Vol.1 No.-

Effects of SBA-15 physicochemical properties on performance of Pd/SBA-15 catalysts in 2-ethyl-anthraquinone hydrogenation

Enxian Yuan,Chan Wu,Guozhu Liu,Guozhu Liu,Li Wang 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.66 No.-

A series of SBA-15 mesoporous silicas with pore sizes ranging between 7 and 26 nm were synthesized and modified by incorporating Al or Mg and functionalization with n-dodecyltrimethoxysilane. Pd/SBA-15 catalysts were prepared and the effects of the pore structure, Al/Mg modifiers and Pd particles distribution on 2-ethyl-anthraquinone hydrogenation have been studied. The catalytic performance improves with enlarging SBA-15 pore size and reaches a plateau at 22.3 nm. The incorporation of Mg into SBA-15 increases the catalytic performance of catalysts. But, the incorporation of Al brings about opposite results. The functionalization of SBA-15 with n-dodecyltrimethoxysilane further enhances the catalytic performance.

Design and Implementation of the Independent Case-Based Teaching System Based on Network Platform

Hengshan Zong,Guozhu Jia,Feng Jin 보안공학연구지원센터 2016 International Journal of Database Theory and Appli Vol.9 No.3

In order to solve the existing problems of case-based teaching, the construction of the independent case-based teaching system is proposed, and the connotation and advantage of independent teaching system are analyzed. With the construction of network teaching platform, case-based teaching process is optimized and function is reorganized through the system layering design and system function module design. The network platform provides support for the construction of the independent case-based teaching system. The independent case-based teaching can promote students’ active learnin

Design and Research on High-Reliability HPEBB Used in Cascaded DSTATCOM

Kun Yang,Yue Wang,Guozhu Chen 전력전자학회 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.3

The H-bridge inverter is the fundamental power cell of the cascaded distribution static synchronous compensator (DSTATCOM). Thus, cell reliability is important to the compensation performance and stability of the overall system. The concept of the power electronics building block (PEBB) is an ideal solution for the power cell design. In this paper, an H-bridge inverter-based “plug and play” HPEBB is introduced into the main circuit and the controller to improve the compensation performance and reliability of the device. The section that discusses the main circuit primarily emphasizes the design of electrical parameters, physical structure, and thermal dissipation. The section that presents the controller part focuses on the principle of complex programmable logic device -based universal controller This section also analyzes typical reliability and anti-interference issues. The function and reliability of HPEBB are verified by experiments that are conducted on an HPEBB test-bed and on a 10 kV/± 10 Mvar DSTATCOM industrial prototype.

A Novel Modulation Scheme and a DC-Link Voltage Balancing Control Strategy for T-Type H-Bridge Cascaded Multilevel Converters

Yue Wang,Yaowei Hu,Guozhu Chen 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.6

The cascaded multilevel converter is widely adopted to medium/high voltage and high power electronic applications due to the small harmonic components of the output voltage and the facilitation of modularity. In this paper, the operation principle of a T-type H-bridge topology is investigated in detail, and a carrier phase shifted pulse width modulation (CPS-PWM) based control method is proposed for this topology. Taking a virtual five-level waveform achieved by a unipolar double frequency CPS-PWM as the output object, PWM signals of the T-type H-bridge can be obtained by reverse derivation according to its switching modes. In addition, a control method for the T-type H-bridge based cascaded multilevel converter is introduced. Then a single-phase T-type H-bridge cascaded multilevel static var generator (SVG) prototype is built, and a repetitive controller based compound current control strategy is designed with the DC-link voltage balancing control scheme analyzed. Finally, simulation and experimental results validate the correctness and feasibility of the proposed modulation method and control strategy for T-type H-bridge based cascaded multilevel converters.

Improvement of oxidation resistance property of C/SiCO nanoporous ceramic composites with TaSi2-MoSi2-ZrB2-borosilicate glass coating

Xiafei Li,Junzong Feng,Guozhu Zhao,Xingyu Wu 한양대학교 청정에너지연구소 2023 Journal of Ceramic Processing Research Vol.24 No.5

To improve the oxidation resistance property of C/SiCO nanoporous ceramic composites, TaSi2-MoSi2-borosilicate glasscoatings and TaSi2-MoSi2-ZrB2-Borosilicate glass coatings were prepared on the surface of C/SiCO nanoporous ceramiccomposites through slurry brushing combined with graphite powder embedding sintering process. The coatings are smooth,flat, without cracks, and tightly bonded to the substrate material. A study was conducted on the thermal stability of coatedsamples in an air atmosphere at 1600 ℃ and the high-temperature oxidation mechanism was analyzed. The results show thatthe coating effectively improves the thermal stability of SiCO nanoporous ceramic composites, and the addition of ZrB2 furtherimproves the oxidation resistance and ablation resistance of the coated samples. At high temperatures, the borosilicate glassin the coating displays a viscous flow state, and the SiO2 glass layer formed on the coatings surface serves as an oxygen barrier. At the same time, the coating has a particle reinforced glass structure inside, which avoid the growth and propagation of cracksand reduce oxygen diffusion channels effectively.