In-plane Vibration Analysis of Rotating Cantilever Curved Beams

Guang Hui Zhang,Zhan Sheng Liu,Hong Hee Yoo 대한기계학회 2007 대한기계학회 춘추학술대회 Vol.2007 No.5

Equations of motion of rotating cantilever curved beams are derived based on a dynamic modeling method developed in this paper. The Kane’s method is employed to derive the equations of motion. Different from the classical linear modeling method which employs two cylindrical deformation variables, the present modeling method employs a non-cylindrical variable along with a cylindrical variable to describe the elastic deformation. The derived equations (governing the stretching and the bending motions) are coupled but linear. So they can be directly used for the vibration analysis. The coupling effect between the stretching and the bending motions which could not be considered in the conventional modeling method is considered in this modeling method. The natural frequencies of the rotating curved beams versus the rotating speed are calculated for various radii of curvature and hub radius ratios.

In-plane vibration analysis of cantilevered circular arc beams undergoing rotational motion

Guang Hui Zhang,Zhan Sheng Liu,Hong Hee Yoo 대한기계학회 2008 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.22 No.1

Equations of motion of cantilevered circular arc beams undergoing rotational motion are derived based on a dynamic modeling method developed in this paper. Kane’s method is employed to derive the equations of motion. Different from the classical linear modeling method which employs two cylindrical deformation variables, the present modeling method employs a non-cylindrical variable along with a cylindrical variable to describe the elastic deformation. The derived equations (governing the stretching and the bending motions) are coupled but linear, so they can be directly used for vibration analysis. The coupling effect between the stretching and the bending motions, which could not be considered in the conventional modeling method, is considered in this modeling method. The effects of rotational speed, arc angle, and hub radius ratio on the natural frequencies of the rotating circular arc beam are investigated through numerical analysis.

Excessive Startle with Novel GLRA1 Mutations in 4 Chinese Patients and a Literature Review of GLRA1-Related Hyperekplexia

Feixia Zhan,Chao Zhang,Shige Wang,Zeyu Zhu,Guang-Chen Jiao,Mingliang Zhao,Li Cao 대한신경과학회 2020 Journal of Clinical Neurology Vol.16 No.2

Background and Purpose Hyperekplexia (HPX), a rare neurogenetic disorder, is classically characterized by neonatal hypertonia, exaggerated startle response provoked by the sudden external stimuli and followed by a shortly general stiffness. Glycine receptor alpha 1 (GLRA1) is the major pathogenic gene of the disease. We described the clinical manifestations of genetically confirmed HPX patients and made a literature review of GLRA1-related HPX to improve the early recognition and prompt the management of the disorder. Methods Extensive clinical evaluations were analyzed in 4 Chinese HPX patients from two unrelated families. Next generation sequencing was conducted in the probands. Sanger sequence and segregation analysis were applied to confirm the findings. Results All four patients including 3 males and 1 female presented with excessive startle reflex, a cautious gait and recurrent falls. Moreover, startle episodes were dramatically improved with the treatment of clonazepam in all cases. Exome sequencing revealed 2 homozygous GLRA1 mutations in the patients. The mutation c.1286T>A p.I429N has been previously reported, while c.754delC p.L252* is novel. Conclusions HPX is a treatable disease, and clonazepam is the drug of choice. By studying and reviewing the disorder, we summarized the phenotype, expanded the genotype spectrum, and discussed the possible pathogenic mechanisms to enhance the understanding and recognition of the disease. Early awareness of the disease is crucial to the prompt and proper administration, as well as the genetic counseling.

Bone Morphogenetic Protein 9 Overexpression Reduces Osteosarcoma Cell Migration and Invasion

Zilan Lv,Ya-guang Weng,Dandan Yang,Jie Li,Min Hu,Min Luo,Xiaoqin Zhan,Peipei Song,Chen Liu,Huili Bai,Baolin Li,Yang Yang,Yingying Chen,Qiong Shi 한국분자세포생물학회 2013 Molecules and cells Vol.36 No.2

Transforming growth factor- (TGF-) is known to pro-mote tumor migration and invasion. Bone morphogenetic proteins (BMPs) are members of the TGF- family expressed in a variety of human carcinoma cell lines. The role of bone morphogenetic protein 9 (BMP9), the most powerful osteogenic factor, in osteosarcoma (OS) progression has not been fully clarified. The expression of BMP9 and its receptors in OS cell lines was analyzed by RT-PCR. We found that BMP9 and its receptors were expressed in OS cell lines. We further investigated the influence of BMP9 on the biological behaviors of OS cells. BMP9 overexpression in the OS cell lines 143B and MG63 inhibited in vitro cell migration and invasion. We further investigated the ex-pression of a panel of cancer-related genes and found that BMP9 overexpression increased the phosphorylation of Smad1/5/8 proteins, increased the expression of ID1, and reduced the expression and activity of matrix metalloproteinase 9 (MMP9) in OS cells. BMP9 silencing induced the opposite effects. We also found that BMP9 may not affect the chemokine (C-X-C motif) ligand 12 (CXCL12)/C-X-C chemokine receptor type 4 (CXCR4) axis to regulate the invasiveness and metastatic capacity of OS cells. Interestingly, CXCR4 was expressed in both 143B and MG63 cells, while CXCL12 was only detected in MG63 cells. Taken together, we hypothesize that BMP9 inhibits the migration and invasiveness of OS cells through a Smad-dependent pathway by downregulating the expression and activity of MMP9.

Three New 11,20-Epoxy-ent-kauranoids from Isodon rubescens

Xu Liu,Ji Zhou Wu,Rui Zhan,Wei Guang Wang,Xue Du,Yan Li,Peng Zhang,Jian Xin Pu,Han Dong Sun 대한약학회 2012 Archives of Pharmacal Research Vol.35 No.12

Three rare and new 11,20-epoxy-ent-kaurane diterpenoids, named jianshirubesins D-F (1-3), along with one known analogue (4), were isolated from the aerial parts of Isodon rubescens. Their structures were established by analysis of spectroscopic data. Found in the MTT assay to evaluate the cytotoxicity of compounds 1, 2, and 4, only 1 could selectively inhibit certain cell lines from proliferating. In addition, a simple structure-activity relationship discussion might suggest a new bioactive moiety, different from the α,β-unsaturated ketone group.

Generation Method of Autonomous Evasive Maneuver Strategy in Air Combat

Lin Li,Zhen Yang,Zhixiao Sun,Guang Zhan,Haiyin Piao,Deyun Zhou 제어로봇시스템학회 2022 제어로봇시스템학회 국제학술대회 논문집 Vol.2022 No.11

Air combat is usually a continuous process involving multiple rounds of missile attacks, UCAV(Unmanned Combat Aerial Vehicle) should consider the impact of maneuver on the entire air combat countermeasure mission rather than solely focusing on safety factors when evading incoming air to air missiles. In this paper, a method of generating autonomous evasive maneuver strategy in UCAV air combat is proposed under the condition of miss distance and energy dissipation. Firstly, the UCAV-missile three-dimensional space pursuit model and the UCAV autonomous evading state space, action space and reward function model are established. Dueling DDQN (Double Deep Q Network) algorithm is used to solve the model, which integrates Double DQN and Dueling DQN Network model. Simulation experiments and analysis show that the method proposed in this paper has significant effectiveness in solving the problem of autonomous evasive maneuvers in air combat under the conditions of miss distance and energy dissipation tactical requirements. The evasive maneuvers strategy obtained can reflect the two tactical requirements of air combat while ensuring the safety of UCAV itself.

A Maneuver Control Method for Stealthy Engagement in Beyond-visual-range Air Combat Based on Sliding Mode Control

Yue Liu,Zhen Yang,Jichuan Huang,Guang Zhan,Xiaoyang Li,Deyun Zhou 제어로봇시스템학회 2022 제어로봇시스템학회 국제학술대회 논문집 Vol.2022 No.11

A S-type engagement of beyond-visual-range (BVR) air combat tactical method based on sliding mode control is proposed, which is aiming at the problem of Doppler pulse (PD) radar blind zone. By introducing the Electronic Support Measures (ESM), the whole tactical process is divided into two sub-processes: quick engagement and stealthy engagement. This paper designs a stealthy engagement process controller based on the double power sliding mode control, and a quick engagement process controller based on the back-stepping second order sliding mode. The simulation experiment shows that our aircraft can use EMS to judge the enemy radar detection information and switch the strategy. And it can successfully enter the enemy radar blind zone through S-type maneuver, occupy the dominant area, which can effectively complete the stealthy engagement.

Melatonin Attenuates Noise Stress-induced Gastrointestinal Motility Disorder and Gastric Stress Ulcer: Role of Gastrointestinal Hormones and Oxidative Stress in Rats

( Lei Zhang ),( Ji T Gong ),( Hu Q Zhang ),( Quan H Song ),( Guang H Xu ),( Lei Cai ),( Xiao D Tang ),( Hai F Zhang ),( Fang E Liu ),( Zhan S Jia ),( Hong W Zhang ) 대한소화기기능성질환·운동학회 2015 Journal of Neurogastroenterology and Motility (JNM Vol.21 No.2

Background/Aims There are increasing evidences for gastrointestinal motility disorder (GIMD) and gastric stress ulcer induced by noise stress. The present study was to investigate the reversed effect of melatonin on GIMD and gastric stress ulcer induced by noise stress and potential mechanism. Methods Noise stress was induced on rats, and melatonin (15 mg/kg) was administered to rats by intraperitoneal injection. Differences were assessed in gastric residual rate (GRR), small intestine propulsion rate (SPR), Guth injury score, cortisol, gastrointestinal hormones (calcitonin-gene-related peptide and motilin) and oxidative stress markers (superoxide dismutase and malondialde hyde) in blood plasma as well as gastric mucosa homogenate with or without melatonin. The pathological examination of gastric mucosa was also performed. Results The GRR and SPR were improved by noise stress compared with control (P < 0.05). The pathological examination and Guth injury score revealed gastric stress ulcer. Moreover, the levels of cortisol, motilin and malondialdehyde in blood plasma and malondialdehyde in gastric mucosa homogenate were increased by noise stress (P < 0.05). CGRP and superoxide dismutase activity in both of blood plasma and gastric mucosa homogenate were significantly decreased (P< 0.05). Furthermore, melatonin reversed changes in GRR, SPR, pathological examination, Guth injury score, cortisol, motilin, CGRP, superoxide dismutase activity and malondialdehyde (P < 0.05). Conclusions Melatonin is effective in reversing the GIMD and gastric stress ulcer induced by noise stress. The underlying mechanism may be involved in oxidative stress and gastrointestinal hormones. (J Neurogastroenterol Motil 2015;21:189-199)

Effect of irradiation temperature on the nanoindentation behavior of P92 steel with thermomechanical treatment

Huang Xi,Shen Yinzhong,Li Qingshan,Li Xiaoyan,Zhan Zixiong,Li Guang,Li Zhenhe 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.7

The nanoindentation behavior of P92 steel with thermomechanical treatment under 3.5 MeV Fe13þ ion irradiation at room temperature, 400 and 700 C was investigated. Pop-in behavior is observed for all the samples with and without irradiation at room temperature, while the temperature dependence of pop-in behavior is only observed in irradiated samples. The average load and penetration depth at the onset of pop-in increase as the irradiation temperature increases, in line with the results of the maximum shear stress. Irradiation induced hardening is exhibited for all irradiated samples, but there is a significant reduction in the hardness of sample irradiated at 700 C in comparison to the samples irradiated at room temperature and 400 C. The ratio of hardness to elastic modulus for all samples decreases with increasing penetration depth except for samples at 700 C. With the increasing of irradiation temperature, the ratio of the irreversible work to the total work gradually decreases. In contrast, it increases for samples without irradiation