Analysis of the PU-2UPS antenna parallel mechanism

Guoxing Zhang,Jinwei Guo,Yulei Hou,Daxing Zeng 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.2

In order to meet the requirements of the antenna pedestal for supporting and driving antenna to complete specific trajectory movement, the PU-2UPS parallel mechanism is proposed for antenna pedestal, where P, U and S represent the prismatic joint, universal joint and spherical joint, respectively. The screw theory is applied to analyze the mobility of the PU-2UPS antenna parallel mechanism (APM). Meanwhile, kinematic analysis of the mechanism is carried out based on the theory of twist and spatial acceleration. Based on the wrench and force balance relationship, the dynamic model of the PU-2UPS APM is established. Therefore, the actuation forces of each actuation joint are obtained. Afterward, the work-space of the PU-2UPS APM is constructed based on the boundary search method. Finally, the mathematical model of the PU-2UPS APM is established by MATLAB software, and the theoretical analysis of the PU-2UPS APM is verified by ADAMS software. The studies have been performed that the PU-2UPS APM is suitable for antenna pedestal in respect of mobility, kinematics and dynamics properties. This research results serve as a fundamental theoretical basis for design and analysis of the APM.

Development of a micro-scale Y – Zr – O oxide-dispersion-strengthened steel fabricated via vacuum induction melting and electro-slag remelting

Guoxing Qiu,Dongping Zhan,Changsheng Liu,Min Qi,Zhouhua Jiang,Huishu Zhang 한국원자력학회 2019 Nuclear Engineering and Technology Vol.51 No.6

In this paper, the CLAM steel strengthened by micro-scale YeZreO was prepared by vacuum inductionmelting followed by electroslag remelting (VIM-ESR). Yttrium (Y) and zirconium (Zr) were easy to aggregatesinto massive yttrium-zirconium-rich inclusions in the steel melted by vacuum inductionmelting (VIM), which would interrupt the continuity of the matrix and reduce the mechanical propertiesof steel. Micron-sized YeZreO inclusions would be produced with the removal of original blocky YeZrrichinclusions and the submicron-sized inclusions smaller than 0.2 mm could be retained in the steel. The small grain size and the better refinement and distribution uniformity of YeZreO inclusions afterremelting would be responsible for the better yield strength and toughness. For VIM-ESR alloy, the ultimatetensile strength is 749 MPa and the yield strength is 642 MPa at room temperature, meanwhilethey are 391 MPa and 367 MPa at 600 C, respectively. Meanwhile, the ductile-brittle transition temperature(DBTT) reduced from 43 C (VIM) to-76 C (VIM-ESR).

Static and Seismic Experimental Study of Novel Prefabricated Beam-Column Joints with Elongated-Hole Brackets

Zhang Zhiwei,Li Dong,Wang Huajie,Li Songling,Qian Hongliang,Bi Yanhua,Wang Guoxing,Jin Xiaofei,Fan Feng 한국강구조학회 2024 International Journal of Steel Structures Vol.24 No.1

To enhance the structural connectivity of prefabricated steel frame systems and augment their construction effi ciency, this study introduces an innovative prefabricated joint design tailored for square steel columns and H-beams characterized by varying beam heights. This study includes both static loading tests and seismic tests performed on full-scale joints featuring two diff erent beam heights. This investigation involved a comprehensive analysis of the static and seismic performance of the joints, employing various performance metrics such as ultimate load capacities, ultimate rotation angles, hysteresis curves, skeleton curves, stiff ness degradation curves, and ductility coeffi cients, in alignment with established structural codes and standards. The results indicate that the plasticity of the H-beam is fully developed, exhibiting a relative slip phenomenon. Additionally, the joints demonstrate commendable rotational capacity, with hysteresis curves consistently manifesting an inverse S-shape and exhibiting noteworthy stiff ness degradation. Furthermore, the comparison with the unimproved joint shows that the novel joint, in addition to being easy to construct, has better ductility and energy dissipation capacity. The results of the study will provide a technical reference for further optimization and application of prefabricated beam-column joints.

Effects of Y and Ti addition on microstructure stability and tensile properties of reduced activation ferritic/martensitic steel

Guoxing Qiu,Dongping Zhan,Changsheng Liu,Min Qi,Zhouhua Jiang,Huishu Zhang 한국원자력학회 2019 Nuclear Engineering and Technology Vol.51 No.5

The effects of Y and Ti on the microstructure stability and tensile properties of the reduced activationferritic/martensitic steel have been investigated. The addition of Y and Ti affected the prior austenitegrain size due to the pinning of the inclusions. Ti addition of 0.008 wt% to the steel was intended topromote the precipitation of nano-sized carbides with a high resistance to coarsening. 8Ti14Y exhibited ahigher yield strength and a lower DBTT than the other alloys due to the fine grain size and additionalprecipitation hardening by (Ti, Ta)-rich MX. After thermal exposure at 550 C for 1500 h, yield strengthwas dropped significantly in exposed 0Ti13Y. On the contrary, a lower reduction of YS was observed in8Ti14Y. The M23C6 in 0Ti13Y and 8Ti14Y and MX in 25Ti14Y and 39Ti15Y coarsened seriously duringageing, which could be responsible for the reduction of the tensile properties of alloys.

Effects of electroslag remelting process and Y on the inclusions and mechanical properties of the CLAM steel

Qiu, Guoxing,Zhan, Dongping,Li, Changsheng,Yang, Yongkun,Jiang, Zhouhua,Zhang, Huishu Korean Nuclear Society 2020 Nuclear Engineering and Technology Vol.52 No.4

Y-containing CLAM steels were melted via vacuum induction melting and electroslag remelting. In this study, the evolution, microstructure, and mechanical properties of the alloy inclusions (ESR-1 (0 wt.% Y), ESR-2 (0.016 wt.% Y) and ESR-3 (0.042 wt.% Y)) were investigated. Further, the number of inclusions in ESRed steel was observed to obviously decrease, and the distributions were more uniform. The fine Y-Al-O inclusions (1-2 ㎛) were the main inclusions in ESR-2. The addition of Y affected the prior austenite grain size (PAGZ), increasing the tensile strength at test temperature. Low ductile-brittle transition temperature (DBTT) was obtained because of the fine PAGZ and dispersive inclusions. For the ESRed CLAM steel with 0.016 wt.% Y, the yield strengths were 621 MPa at 20 ℃ and 354 MPa at 600 ℃ in air. Further, the uniform elongation and elongation of the ESR-2 alloy were 5.5% and 20.1% at 20 ℃, respectively. Meanwhile, the DBTT tested using full-size Charpy impact specimen (55 cm × 10 cm × 10 cm) was reduced to -83 ℃.

Morroniside on anti-inflammation activities in rats following acute myocardial infarction

Yu, Bangxing,Zhang, Guoxing,An, Yi,Wang, Wen The Korean Society of Pharmacology 2018 The Korean Journal of Physiology & Pharmacology Vol.22 No.1

Our previous studies have confirmed that morroniside has neuroprotective effects. However, the effects of morroniside on cardiac myocardium remain unknown. Rats were anaesthetized with 10% chloral hydrate (0.35~0.4 mL/kg) and an acute myocardial infarction (AMI) was induced by ligating the anterior descending coronary artery (LAD). Following AMI, morroniside was administered intragastrically for 3 consecutive days at doses of 45, 90 and 180 mg/kg, respectively. Lactate dehydrogenase (LDH) and cardiac troponin T (cTnT) activities in AMI rats in the serum were detected with commercial kits. The expression of IL-6, $IL-1{\beta}$ and $TNF-{\alpha}$ in myocardium was detected by Western blotting analysis. We observed a significant decline in the Q(q) wave amplitude in morroniside-treated rats after 72 h. Additionally, treatment of morroniside decreased the levels of LDH and cTnT in AMI rats. We also observed that morroniside reduced the expression of IL-6, $IL-1{\beta}$ and $TNF-{\alpha}$ in myocardium. Taken together, our findings demonstrate that morroniside had effective anti-inflammatory properties in AMI rats.

Morroniside on anti-inflammation activities in rats following acute myocardial infarction

Bangxing Yu,Guoxing Zhang,Yi An,Wen Wang 대한약리학회 2018 The Korean Journal of Physiology & Pharmacology Vol.22 No.1

Our previous studies have confirmed that morroniside has neuroprotective effects. However, the effects of morroniside on cardiac myocardium remain unknown. Rats were anaesthetized with 10% chloral hydrate (0.35~0.4 mL/ kg) and an acute myocardial infarction (AMI) was induced by ligating the anterior descending coronary artery (LAD). Following AMI, morroniside was administered intragastrically for 3 consecutive days at doses of 45, 90 and 180 mg/kg, respectively. Lactate dehydrogenase (LDH) and cardiac troponin T (cTnT) activities in AMI rats in the serum were detected with commercial kits. The expression of IL-6, IL-1β and TNF-α in myocardium was detected by Western blotting analysis. We observed a significant decline in the Q(q) wave amplitude in morroniside-treated rats after 72 h. Additionally, treatment of morroniside decreased the levels of LDH and cTnT in AMI rats. We also observed that morroniside reduced the expression of IL-6, IL-1β and TNF-α in myocardium. Taken together, our findings demonstrate that morroniside had effective anti-inflammatory properties in AMI rats.

Morroniside on anti-inflammation activities in rats following acute myocardial infarction

Bangxing Yu,Guoxing Zhang,Yi An,Wen Wang 대한생리학회-대한약리학회 2018 The Korean Journal of Physiology & Pharmacology Vol.13 No.4

Our previous studies have confirmed that morroniside has neuroprotective effects. However, the effects of morroniside on cardiac myocardium remain unknown. Rats were anaesthetized with 10% chloral hydrate (0.35~0.4 mL/kg) and an acute myocardial infarction (AMI) was induced by ligating the anterior descending coronary artery (LAD). Following AMI, morroniside was administered intragastrically for 3 consecutive days at doses of 45, 90 and 180 mg/kg, respectively. Lactate dehydrogenase (LDH) and cardiac troponin T (cTnT) activities in AMI rats in the serum were detected with commercial kits. The expression of IL-6, IL-1β and TNF-α in myocardium was detected by Western blotting analysis. We observed a significant decline in the Q(q) wave amplitude in morroniside-treated rats after 72 h. Additionally, treatment of morroniside decreased the levels of LDH and cTnT in AMI rats. We also observed that morroniside reduced the expression of IL-6, IL-1β and TNF-α in myocardium. Taken together, our findings demonstrate that morroniside had effective anti-inflammatory properties in AMI rats.

Dielectric Meta-Holograms Enabled with Dual Magnetic Resonances in Visible Light

Li, Zile,Kim, Inki,Zhang, Lei,Mehmood, Muhammad Q.,Anwar, Muhammad S.,Saleem, Murtaza,Lee, Dasol,Nam, Ki Tae,Zhang, Shuang,Luk’yanchuk, Boris,Wang, Yu,Zheng, Guoxing,Rho, Junsuk,Qiu, Cheng-Wei American Chemical Society 2017 ACS NANO Vol.11 No.9

<P>Efficient transmission-type meta-holograms have been demonstrated using high-index dielectric nanostructures based on Huygens principle. It is crucial that the geometry size of building blocks be judiciously optimized individually for spectral overlap of electric and magnetic dipoles. In contrast, reflection-type meta-holograms using the metal/insulator/metal scheme and geometric phase can be readily achieved with high efficiency and small thickness. Here, we demonstrate a general platform for design of dual magnetic resonance based meta-holograms based on the geometric phase using silicon nanostructures that are quarter wavelength thick for visible light. Significantly, the projected holographic image can be unambiguously observed without a receiving screen even under the illumination of natural light. Within the well-developed semiconductor industry, our ultrathin magnetic resonance-based meta-holograms may have promising applications in anticounterfeiting and information security.</P>