Spatial synchronization behavior of vibration system with tri-motor excitation

Pan Fang,Shuangquan Shi,Tao Chen,Min Zou,Duyu Hou,Zhiliang Zhang 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.9

The existing research of vibration synchronization among multiple rotors is mainly concentrated on plane vibration system. In this paper, the synchronization mechanism of the spatial vibration system actuated with tri-motor rotating in identical direction is studied. Firstly, the dynamic model is established, and the motion differential equations are deduced via Lagrange formulation. Then, small parameter average method is applied to explore the synchronization condition; Lyapunov equation and Routh-Hurwitz criterion are introduced to analyze the synchronization stability. Finally, the influence of the system parameter on synchronization is discussed by numerical calculation, and the electromechanical coupling simulation based on Matlab/Simulink is given to confirm the reliability of the theoretical analysis. The research result indicates that the vibration synchronization is affected by the horizontal distance between two coaxial motors, the installation height and the masses of three eccentric rotors (ERs), but the influence of the horizontal distance between coaxial motor and noncoaxial motor on synchronization is small.

INTEGRATED STEADY-STATE AND DYNAMIC SIMULATION OF MULTI-UNIT AIR CONDITIONERS BASED ON TWO-PHASE FLUID NETWORK MODEL

HONGBO XU,SHUANGQUAN SHAO,Huiming Zou,Changqing Tian 대한설비공학회 2012 International Journal Of Air-Conditioning and Refr Vol.20 No.4

An integrated simulation model is developed to investigate the steady-state and dynamic performance of multi-unit air conditioners (MUACs). It is built as two-phase fluid network which is able to describe different systems by incidence matrixes. And the submodels are embedded in the system framework, where the submodels can be either steady-state or dynamic model, distributed parameter or lumped parameter model. For this case, the numerical submodels are employed with moving-boundary models of condenser and evaporator, steady-state models of compressor and electronic expansion valve. The comparison with experimental data shows that it cannot only predict the steady-state performance, but also catch dynamic trends with high accuracy, for example, the differences of evaporating pressure < ${\pm}4%$, condensing pressure < ${\pm}3%$, compressor discharge temperature < ${\pm}4^{\circ}C$, superheating degree < ${\pm}2^{\circ}C$ and subcooling degree < ${\pm}1^{\circ}C$. Therefore, the simulation model is confirmed as an effective tool to analyze the steady and transient characteristics and optimize the design and control algorithm of MUACs.

Research in Estimation of Temperature for Power Battery Based on Back Propagation Neural Network

Haiying Wang,Shuangquan Liu,Tianjun Sun,Gechen Li 보안공학연구지원센터 2013 International Journal of Smart Home Vol.7 No.3

Improved Wavelet Threshold for Gray Scale Image Denoising

Liying Yuan,Junfeng Wu,Shuangquan Li 보안공학연구지원센터(IJSIP) 2014 International Journal of Signal Processing, Image Vol.7 No.3

Performance characteristics around the TDC of linear compressor based on whole-process simulation

Huiming Zou,Mingsheng Tang,HONGBO XU,SHUANGQUAN SHAO,Changqing Tian 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.10

A whole-process simulation platform is established for linear compressor to analyze the performance characteristics on different pistondisplacement conditions from small oscillation without pumping till to rushing out of the top dead center (TDC). The measuring methodsof the related parameters in the model are presented and the values of these parameters are obtained from an actual test. The simulatedresults agreed well with the experimental results under the same working conditions. The errors of the effective voltage, the effectivecurrent, the compression efficiency and the phase angle between the current and the displacement were within ±6.9%,±8.5%,±6.2%and±13.4%, respectively. Based on this simulation platform, the performance characteristic around the TDC of the linear compressor ondifferent working conditions is analyzed. The performance comparison on 60 Hz shows that the compression efficiency near to the TDCon 0.7 MPa is higher than that on 0.5 MPa because the phase angle α under that condition is around 90°, but the operation reliability on0.7 MPa is worse than that on 0.5 MPa because the jump phenomenon happens when the piston displacement goes near to the TDC. Thejump phenomenon results in unstable operation as the piston displacement jumps from the position before the TDC to the position afterthe TDC. According to the simulation on different power frequency, two important performance characteristics are inferred. One is thatthere is an inflection point in the curve of the phase angle α versus the displacement at the TDC. This characteristic is a good choice forthe TDC detection. The other is that the jump phenomenon is prone to happening when there exist different displacement responses onthe same voltage value, becoming inconspicuous when the power frequency is decreased and disappearing when the power frequency isincreased. Based on this characteristic, the jump phenomenon can be avoided through suitable system configuration and frequency adjustment.

Expression profiling of the mitogen-activated protein kinase gene family reveals their diverse response pattern in two different salt-tolerant Glycyrrhiza species

Cao Aiping,Gao Ling,Wang Fei,Tong Xuechen,Xie Shuangquan,Chen Xifeng,Lu Tianxin,Shen Haitao,Liu Hailiang,Jin Xiang,Li Hongbin 한국유전학회 2022 Genes & Genomics Vol.44 No.7

Background: Mitogen-activated protein kinases (MPKs) play important role in response to environmental stress as crucial signal receptors or sensors. Our previous study indicated that salt stress acts as a positive factor to stimulate the production of pharmacodynamic metabolites in the medicinal plant Glycyrrhiza uralensis. Currently, little is known about the MPK gene family and their functions in the medicinal plant G. uralensis. Objective: Identification, comprehensive bioinformatic analysis, expression profiling, and response pattern under salt stress of the G. uralensis GuMPK gene family. Methods: Genome-wide investigation and expression profiling of the MPK gene family in G. uralensis, and their phylogenetic relationships, evolutionary characteristics, gene structure, motif distribution, promoter cis-acting element, and expression pattern under salt stress in two different salt-tolerant Glycyrrhiza species were performed. Results: A total of 20 G. uralensis GuMPK genes were identified and categorized into five groups, and had conserved gene structure and motif distribution. Expression profiling of GuMPK genes suggested their potentially diverse functions in plant growth and in response to phytohormones and environmental stress, particularly GuMPK1, 2, 5, and 10 as key components for G. uralensis in response to abiotic stress. Further expression analysis under NaCl treatment in two different salt-tolerant Glycyrrhiza species displayed the MPKs' different response patterns, emphasizing the role of MPK2, 5, 7, and 16 as potentially crucial genes for Glycyrrhiza to respond to salt stress. Conclusion: Our results provide a genome-wide identification and expression profiling of MPK gene family in G. uralensis, and establish the foundation for screening key responsive genes and understanding the potential function and regulatory mechanism of GuMPKs in salt responsiveness.

Effectiveness of the Endplate Reduction Technique Combined With Bone Grafting for the Treatment of Thoracolumbar Fractures by Using Posterior Short-Segment Fixation

Jiguang Hou,Dong Ren,Yufeng Chen,Lindan Geng,Shuangquan Yao,Haotian Wu,Pengcheng Wang 대한척추신경외과학회 2023 Neurospine Vol.20 No.1

Objective: This study aimed to examine the effect of the endplate reduction (EPR) technique combined with bone grafting for treating thoracolumbar burst fractures using posterior shortsegmental fixation. Methods: Patients with thoracolumbar fractures admitted between January 2018 and October 2021 were retrospectively analyzed, and those meeting the criteria were assigned to the EPR group and the intermediate screws (IS) group. The vertebral wedge angle (VWA), Cobb angle (CA), anterior vertebral body height (AVBH), middle vertebral body height (MVBH), upper endplate line (UEPL), upper intervertebral angle (UIVA), and upper intervertebral disc height (UIDH) indices were examined and compared preoperatively, first day postoperatively, as well as at 12 months postoperatively. Results: The result indicated that the EPR group achieved better MVBH reduction (p < 0.001), UEPL reduction (p < 0.001), vertebral body fracture healing (p = 0.006), as well as implant breakage (p = 0.04) than the IS group; VWA (p < 0.001), CA (p = 0.005), AVBH (p < 0.001), MVBH (p < 0.001), UEPL (p < 0.001), and UIDH (p < 0.001) were lost after reduction less than those in the IS group. There was no significant difference in operative time (p = 0.315) and intraoperative bleeding (p = 0.274) between the 2 groups. Conclusion: The EPR group achieved better results in repositioning and maintaining MVBH and endplate morphology, with less correction loss after the reduction of the VWA, CA, AVBH, and endplate morphology. The EPR group exhibited a better healing pattern after vertebral fracture and disc degeneration was better relieved.