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Hai-Wei Chen,Wei-Xi Ji,Qiu-Ju Zhang,Yi Cao,Sheng-Yao Fan 대한기계학회 2012 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.26 No.2
This paper discusses a method for vibration isolation of a vertical axis automatic washing machine with a hydraulic balancer. First, a way to isolate vibration through a small amplitude of the suspension rod’s axial force is proposed, and a base circle of a cone along which the lower joint of a suspension rod moves is discussed. Based on the circle, a geometric constraint involving the slant angle of the suspension rod, the deflection angle of the washing/spinning assembly, the suspension radius of the tub and the eccentricity of the system at the steady state is derived. Considering that the trace along which the suspension rod moves is also affected by the dynamics of the system, a governing equation satisfying the equilibrium conditions of the centrifugal forces and torques is obtained. Combing the geometric constraint and governing equation together achieves a general governing equation for vibration isolation of the system. Finally, the general governing equation is proven by simulations, and the relations between the optimal installing height and several parameters are discussed.
Design and Analysis of an Active Balancing Mechanism for a Vertical Axis Washing Machine
Hai-Wei Chen,Xun-Ting Yuan,Zhen Sun,Qiu-Qi Mou,Ming Xiong,Wei-Hua Wang 한국정밀공학회 2022 International Journal of Precision Engineering and Vol.23 No.7
In recent years, active balancing of washing machines has drawn much attention from manufactures. This paper proposes a novel active balancing mechanism for vibration suppression of a vertical axis washing machine which employs water for counteracting the unbalanced laundry. At first, a novel structure with two balancing planes sharing only one set of nozzles for injecting water is designed and the balancing capability of the structure is analyzed. Then, a dynamic model of the active balancing system is constructed. Vibration characteristics of the system including changes of the vibration amplitude and phase angle under different influences are studied. After that, a strategy for identifying the imbalance is proposed and an active control method is designed. At last, a washing machine armed with the active mechanism is manufactured. Both a fixed eccentric block and a pile of randomly distributed laundry are used to test the balancing effect. The results show that lateral vibrations of the washer can be greatly reduced by the active mechanism. Due to the simplicity of the structure and the satisfactory balancing effect, the mechanism proposed has a big potential to be employed in future washing machines.
Automatic balancing of a flexible supported rotor with two disks by two ball balancers
Hai-Wei Chen,Yan-Bin Chen,Zhen Sun,Zhi Wang 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.7
This paper studies automatic balancing of a flexible supported rotor with two disks by two ball balancers. Firstly, reduced dynamic descriptions of different components in the rotor are derived using a special method according to Lagrangian equation, based on which a general vibration model of the rotor system is then constructed. Secondly, equations governing frequency responses of the rotor are derived and working principles of the balls in the rotor are illustrated based on basic dynamic phenomena. Thirdly, an autonomous model of the rotor system is built with equations governing movement of the balls derived. Three equilibrium solutions are discovered whose dynamic characteristics are then studied using numerical bifurcation analysis method. Finally, locations of the balls at the steady state are observed using a high speed camera, and the capability of the two balancers for automatic balancing under different conditions is validated.
Design of Horizontal Axis Washing Machine with Ball Balancer and MR Dampers
Hai-Wei Chen,Qiu-Ju Zhang 한국정밀공학회 2017 International Journal of Precision Engineering and Vol.18 No.12
This paper discusses design of a horizontal axis washing machine with a ball balancer and four Magnetorheological (MR) dampers. At first, the minimum motion space needed by the tub and the resistance force for preventing walking are derived for evaluating dynamic performances of the washer. Four MR dampers are designed, manufactured and tested. A multiple-ball model is built for the balancer and two acceleration phases are designed for the spin drying process. Then, simulations are carried out based on a fullfactorial experiment design and the Analysis of Variance (ANOVA) method is used to evaluate the significance of six parameters. A cubic polynomial regression model is constructed and parametric optimization is carried out using a hybrid optimization scheme to obtain optimum parameter values. Several control strategies of the MR dampers for enhancing walking resistance capability of the washer are proposed. At last, experiments are done on a prototype of the horizontal axis washer with several conclusions validated.
( Da Wei Chen ),( Zhen Quan Yang ),( Xia Chen ),( Yu Jun Huang ),( Bo Xing Yin ),( Fei Xiang Guo ),( Hai Qing Zhao ),( Jia Di Huang ),( Yun Wu ),( Rui Xia Gu ) 한국미생물 · 생명공학회 2015 Journal of microbiology and biotechnology Vol.25 No.5
Accumulating evidence indicates that lactic acid bacteria could improve host physiology and lipid metabolism. To investigate the effect of the gut microbiota on host lipid metabolism, a hyperlipidemic rat model was established by feeding rats a high-fat diet for 28 days, and the gut microbiota of the rats was analyzed using real-time PCR before and after administration of Lactobacillus rhamnosus hsryfm 1301 and its fermented milk for 28 days. The findings showed that the Lactobacillus spp., Bifidobacterium spp., Bacteroides spp., and Enterococcus spp. content in the hyperlipidemic rats gut was increased significantly (p < 0.05), while the Clostridium leptum and Enterobacter spp. content was decreased significantly after intervening with L. rhamnosus hrsyfm 1301 and its fermented milk for 28 days (p < 0.05). Furthermore, the lipid levels of the serum and the liver were decreased significantly (p < 0.05) and the fecal water content was increased significantly (p < 0.05) in the hyperlipidemic rats after the intervention, and hepatocyte fatty degeneration of liver tissues was also prevented. A positive correlation was observed between the Clostridium leptum content and the level of serum cholesterol, triglycerides, low-density lipoprotein, and high-density lipoprotein, and a negative correlation was observed between the Enterobacter spp. content and the Lactobacillus spp. and Bifidobacterium spp. content in the hyperlipidemic rats gut. These results suggest that the gut microbiota and lipid metabolism of hyperlipidemic rats could be improved by supplementation with L. rhamnosus hsryfm 1301 and its fermented milk.
Electronic Structures and Optical Properties of CuSCN with Cu Vacancies
Wei Jin,Guo-Qing Yue,Fu-Shun Ke,Song Wu,Hai-Bin Zhao,Liang-Yao Chen,Song-You Wang,Yu Jia 한국물리학회 2012 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.60 No.8
Based on density functional theory (DFT) within the generalized gradient approximation (GGA) using the CASTEP code, we calculated the formation energy of a Cu vacancy, as well as the band structure and the optical properties of β-CuSCN with Cu vacancies. Removal a Cu atom from the 32-site and the 72-site supercell results in an enlargement of the band-gap and a slight relaxation in the lattice parameter. An accepter level above the valence band maximum is observed in the 32-site supercell with a Cu vacancy, which results in the onset of a small absorption pre-peak at 0.65 eV.
Chen Xu,Zheng-Qiang Yang,Sheng Liu,Wei Yang,Hai-Bin Shi,Wei-Zhong Zhou 소화기인터벤션의학회 2021 International journal of gastrointestinal interven Vol.10 No.2
Background: Percutaneous radiologic gastrostomy (PRG) was considered as an alternative technique for long-term enteral nutrition, and the current study is aimed to evaluate the feasibility and safety of this technique in patients with amyotrophic lateral sclerosis (ALS) at a single medical center. Methods: From July 2017 to October 2020, a total of 14 patients underwent PRG with ALS were included in this retrospective study with a median age of 64.0 years, and 78.6% were male. The procedure comprised a dilation of the stomach via a nasogastric catheter, followed by puncture and gastrostomy tube placement under fluoroscopic guidance. The technical success rate and clinical outcomes were recorded over 3 months following the procedure. Results: The technical success rate was 100%. During the follow-up period, minor complications were reported in 2 of patients (14.3%) including superficial skin infection and early tube block. Neither major complications nor mortality were observed. Body mass index of the patients increased significantly from 16.4 ± 2.1 kg/m2 to 17.1 ± 2.0 kg/m2 (t = –13.77; P < 0.001), and the albumin level increased significantly from 37.5 ± 2.3 g/L to 41.8 ± 1.6 g/L (t = –8.82, P < 0.001). Conclusion: PRG is a relatively safe and effective method for ALS patients, and deserves widespread clinical acceptance.
Expression Analysis of miRNAs in Porcine Fetal Skeletal Muscle on Days 65 and 90 of Gestation
Chen, Jian-hai,Wei, Wen-Juan,Xiao, Xiao,Zhu, Meng-Jin,Fan, Bin,Zhao, Shu-Hong Asian Australasian Association of Animal Productio 2008 Animal Bioscience Vol.21 No.7
MiRNAs (microRNAs) are a class of small non-coding RNA molecules of ~21 nucleotides that down- regulate the expression of target genes at post-transcriptional level. In this study, we first accomplished a preliminary scan of miRNA expression using 65 and 90 day fetal pig skeletal muscle samples by microarray hybridization, and 34 miRNAs showed strong positive signals. Five of these miRNAs were selected for further investigation by real-time RT-PCR. The statistical analyses indicated that three miRNAs exhibited significant differential expression (p<0.05) during porcine muscle development from 65 to 90 days of gestation, e.g., miR-24 and miR-424 were down-regulated while miR-133a was up-regulated. Multi-tissue RT-PCR was performed to detect the expression patterns of the five miRNA precursors. The results showed that most of these precursor miRNAs were ubiquitously expressed in different porcine tissues.
Chemical Constituents from the Aerial Parts of Isodon coetsa and their Cytotoxicity
Wei Zhao,Jian Xin Pu,Xue Du,Yong Zhao,Fei He,Hai Bo Zhang,Yong Bo Xue,Wei Lie Xiao,Han Dong Sun,Ying Li Wu,Guo Qiang Chen 대한약학회 2011 Archives of Pharmacal Research Vol.34 No.12
Three new compounds (1-3), including a neolignan, a triterpenoid, and a diterpenoid, together with twenty known compounds (4-23), were isolated from the aerial parts of Isodon coetsa. Their structures and relative configurations were elucidated on the basis of spectroscopic data. Compounds 1, 3, 5-9, 11-13, 16-17, and 19-23 were evaluated for their cytotoxicity against HT-29, BEL-7402, and SK-OV-3 human tumor cell lines. Compound 7 showed significant inhibitory effects on all three types of cells, with IC50 values of 2.52, 3.06, 2.14 μM, respectively.