INFLUENCE OF TETRAHEDRON-LIKE PENETRATING FRAMES ON LOCAL VELOCITIES

ZHONGMING YAN,CHUNTIAN ZHOU,LONGHUA WU,RUOHUA LI 한국수자원학회 2005 한국수자원학회 학술대회 Vol.2005 No.1

Micro-vessel Segmentation and Tiny Particle Speed Estimation

Zhongming Luo,Zhuofu Liu,Weijie Li,Dongyang Zhao 보안공학연구지원센터(IJSIP) 2013 International Journal of Signal Processing, Image Vol.6 No.4

Study on the lubrication state and pitting damage of spur gear using a 3D mixed EHL model with fractal surface roughness

Youhua Li,Lubing Shi,Zhongming Liu,Xiaopeng Wang,Xuetao Qiao,Zhihong Zhang,Shidang Yan 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.12

For high-speed, heavy-load gear units, the meshing tooth surfaces are generally under the mixed lubrication state, which is crucial for gear pitting or micro pitting damage. To clarify the effects of lubrication state on tooth pitting damage, carrying out both numerical and experimental studies on the contact severity of gears under different lubrication states is necessary. In this paper, a 3D line-contact elasto hydrodynamic lubrication model considering fractal surface roughness was developed and used to investigate the lubrication characteristics of involute gears. Both the distributions of pressure and film thickness fluctuated under the rolling contact of rough surfaces. The fluctuations became more substantial with the increase of load and roughness. Furthermore, from the calculated film thickness ratio λ, the contact of gear tooth surfaces with a fractal roughness of Ra = 0.8 μm was always under full lubrication state (λ > 1). When the roughness was increased to Ra = 3.2 μm, the contact was first transmitted into the mixed lubrication state (0.2 < λ < 1) under the load of 1000 N*m and finally deteriorated to boundary lubrication state (λ < 0.2) under the load of 2000 N*m. The boundary lubrication state that occurred under the contact of highly rough surfaces could induce the formation of gear pitting damage. The contact fatigue test showed the gear tooth surface roughness increased from 0.7 μm to around 2.7 μm after 8 million running cycles and then suffered pitting failure after another 2 million cycles, which was consistent with the simulation analysis prediction.

Evaluation of 관-Amyloid Peptides Fibrillation Induced by Nanomaterials Based on Molecular Dynamics and Surface Plasmon Resonance.

Hou, Yafei,Li, Pengfei,Zhou, Hongjian,Zhu, Xiaoli,Chen, Haifeng,Lee, Jaebeom,Koh, Kwangnak,Shen, Zhongming,Chen, Hongxia American Scientific Publishers 2015 Journal of Nanoscience and Nanotechnology Vol.15 No.2

<P>This report investigated the effect of carbon nanomaterials, single-wall carbon nanotube (SWCNT) and graphene oxide, on fibrillation of 관-amyloid 40 (A관40) based on surface plasmon resonance (SPR) and molecular dynamics (MD). MD simulations are carried out in order to reveal the molecular mechanisms of the interaction between nanomaterials and A관40. The strong interaction between A관40 and nanomaterials is related to Van der Waals forces and the Coulomb force, inducing delicate manipulation of the main bonding energy for fibrillation of A관40. The interaction energy between the A관 peptide and graphene is higher than that of SWCNT. Experimental results show both carbon nanomaterials enhance the appearance of a critical nucleus for nucleation of peptide fibrils. Graphene is more beneficial to assist the nucleation process than SWCNT. Combination of SPR and molecular dynamics could be a high-throughput method to screen protein fibrillation.</P>

Stability Analysis of Soil Slope Subjected to Perched Water Condition

Dong Tang,Zhongming Jiang,Tao Yuan,Yi Li 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.9

Perched water zone occurs in the subsurface of the slope under heavy rainfall or above an impeding layer with relatively low permeability. It causes a decrease in the shear strength of the soil and the increase in the loading on the slope. As the most used method of estimate the slope stability, the limit equilibrium method considers the influence of rainfall infiltration on the slope stability by increasing the underground water table and decreasing the shear strength parameters on the slip surface. However, the contribution of perched pore water pressure is usually ignored. To incorporate the effect of perched water pressure into the stability analysis, the Bishop’s simplified method and Janbu’s simplified method are modified to perform stability analysis in the situation of circular and composite slip surfaces, respectively. The detailed methodology and numerical implement procedure are presented. Then, three examples are adopted to verify the proposed methods and to investigate the impact of the perched water zone on slope stability. The results show that the program developed in this study has considerable accuracy compared to commercial software. The pore water pressure in the perched water zone has important impacts on slope stability, especially when the depth of the perched water zone is greater than 4 m. Ignoring the perched pore water pressure in the slope stability analysis might overestimate the safety status of the slope.

Study on the Method of Closed Loop Control for Gas Engine

Xiaocheng Ge,Zhongming Xu,Jingbo Li,Bowen Zou 보안공학연구지원센터 2015 International Journal of Smart Home Vol.9 No.4

With the increasing number of vehicles, society and environmental problems become much more seriously. Aiming at the serious problems, CNG engine, which has better emission performance, has been paid much more attention. However, the CNG engine also has its own disadvantages, such as engine power deterioration, great influence of different mixture ratios of the gas and air on the optimum ignition time of the engine, and so on. Therefore, adaptive control for the air-fuel ratio and ignition timing should be properly adjusted with the consideration of the engine power, economy and emissions. There are two methods of controlling the ignition timing: mechanical and electronic control. In this paper, we develop an adoptive control method based on electronic control. According to the verification, the method can improve the efficiency of the CNG engine. It can be shown the validity of the adoptive method.

Magnetic alignment of MnBi crystals and magnetic properties of MnBi-Bi composites

Yongsheng Liu,Jincang Zhang,Zhongming Ren,Shixun Cao,Xiaoyong Zhang,Guangqiang Jia,Kang Deng,Xi Li,Junxi Zhang 한국물리학회 2007 Current Applied Physics Vol.7 No.5

Below Curie temperatureTC, MnBi crystals are aligned alongc-axis in a Bi matrix under a fabrication eldHfof 0.5 T. AboveTC,this alignment is also accomplished by quenching under a highHfof 10 T. Such a method has a prominent feature that MnBi crystalsgrow preferentially and congregate along theHfdirection. Magnetic testing shows a pronounced anisotropy in magnetization in direc-tions normal and parallel toHf, resulting from the alignment. In the case of the alignment belowTC,Hfincreases the transition temper-ature of spin-reorientation and the change in magnetization.

Genome‑wide identification and characterization of the AMPK genes and their distinct expression patterns in response to air exposure in the Manila clam (Ruditapes philippinarum)

Jingtian Wang,Lei Fang,Qidi Wu,Dongdong Li,Zhongming Huo,Xiwu Yan 한국유전학회 2020 Genes & Genomics Vol.42 No.1

Introduction AMP-activated protein kinases (AMPK) are heterotrimeric complexes. The main upstream phosphorylase has AMP-dependent LKB1 and Ca2+-dependent CaMKK beta. AMPK also includes an auto-inhibitory domain and a region associated with beta and gamma subunits, which regulate a variety of cellular activities and energy metabolism. The increase in the ratio of AMP/ATP can stimulate the activation of AMPK. Once AMPK is activated, pathways to ATP consumption (e.g., fat, cholesterol, and protein synthesis) will be shut down. The pathway to ATP generation (e.g., oxidation of fat and glycolysis pathway) will be activated. AMPK genes have not been systematically characterized in marine invertebrates. Methods In this study, we identified and characterized three AMPK genes, AMPK-α, AMPK-β, and AMPK-γ, in the Manila clam (Ruditapes philippinarum). To gain insight into the role of AMPK genes during clam energy metabolism, quantitative real-time PCR was used to investigate the expression profiles in the different stages of clam development, in healthy adult tissues, and after air exposure at two different temperatures. Results Phylogenetic and protein structural analyses were conducted to determine the identity and evolutionary relationships of these genes. The structural features of the genes were relatively well-conserved, relative to the AMPK genes of other vertebrates. The expression of genes was significantly induced 3–48 h after air exposure. Conclusinon AMPK-α, AMPK-β and AMPK-γ are involved in clam energy metabolism. Increased expression levels of AMPK genes in the gill and intestine of Manila clam in response to air exposure implied a strong adaptability to the coastal environment.

Intravenous patient-controlled analgesia hydromorphone combined with pregabalin for the treatment of postherpetic neuralgia: a multicenter, randomized controlled study

( Ying Huang ),( Chenjie Xu ),( Tao Zeng ),( Zhongming Li ),( Yanzhi Xia ),( Gaojian Tao ),( Tong Zhu ),( Lijuan Lu ),( Jing Li ),( Taiyuan Huang ),( Hongbo Huai ),( Benxiang Ning ),( Chao Ma ),( Xinx 대한통증학회 2021 The Korean Journal of Pain Vol.34 No.2

Background: Postherpetic neuralgia (PHN) is the most common complication of acute herpes zoster. The treatment of PHN remains a challenge for clinical pain management. Despite the effectiveness of anticonvulsants, antidepressants, and lidocaine patches in reducing PHN, many patients still face intractable pain disorders. In this randomized controlled study, we evaluated whether hydromorphone through intravenous patient-controlled analgesia (IV PCA) was effective in relieving PHN. Methods: Patients with PHN were randomly divided into two groups, one group received oral pregabalin with IV normal saline, another group received oral pregabalin with additional IV PCA hydromorphone for two weeks. Efficacy was evaluated at 1, 4, and 12 weeks after the end of the treatments. Results: Two hundred and one patients were followed up for 12 weeks. After treatment, numerical rating scale (NRS) score of patients in the hydromorphone group was significantly lower than that of the control group, and the difference of NRS scores between the two groups was statistically significant at 4 and 12 weeks after treatment. The frequency of breakthrough pain in the hydromorphone group was significantly lower than that in the control group 1 and 4 weeks after treatment. After treatment, the quality of sleep in the hydromorphone group was significantly improved compared with the control group. The most common adverse reactions in the hydromorphone group were dizziness and nausea, with no significant respiratory depression. Conclusions: IV PCA hydromorphone combined with oral pregabalin provides superior pain relief in patients with PHN, which is worthy of clinical application and promotion.

Endovascular versus Medical Management of Acute Basilar Artery Occlusion: A Systematic Review and Meta-Analysis of the Randomized Controlled Trials

Mohamad Abdalkader,Stephanos Finitsis,Chuanhui Li,c Wei Hu,Xinfeng Liu,Xunming Ji,Xiaochuan Huo,Fana Alemseged,Zhongming Qiu,Daniel Strbian,Volker Puetz,James E. Siegler,Shadi Yaghi,Kaiz Asif,Piers Kl 대한뇌졸중학회 2023 Journal of stroke Vol.25 No.1

Background and Purpose The optimal management of patients with acute basilar artery occlusion (BAO) is uncertain. We aimed to evaluate the safety and efficacy of endovascular thrombectomy (EVT) compared to medical management (MM) for acute BAO through a meta-analysis of randomized controlled trials (RCTs). Methods We performed a systematic review and meta-analysis of RCTs of patients with acute BAO. We analyzed the pooled effect of EVT compared to MM on the primary outcome (modified Rankin Scale [mRS] of 0–3 at 3 months), secondary outcome (mRS 0–2 at 3 months), symptomatic intracranial hemorrhage (sICH), and 3-month mortality rates. For each study, effect sizes were computed as odds ratios (ORs) with random effects and Mantel-Haenszel weighting. Results Four RCTs met inclusion criteria including 988 patients. There were higher odds of mRS of 0-3 at 90 days in the EVT versus MM group (45.1% vs. 29.1%, OR 1.99, 95% confidence interval [CI] 1.04–3.80; P=0.04). Patients receiving EVT had a higher sICH compared to MM (5.4% vs. 0.8%, OR 7.89, 95% CI 4.10–15.19; P<0.01). Mortality was lower in the EVT group (35.5% vs. 45.1%, OR 0.64, 95% CI 0.42–0.99; P=0.05). In an analysis of two trials with BAO patients and National Institutes of Health Stroke Scale (NIHSS) <10, there was no difference in 90-day outcomes between EVT versus MM. Conclusion In this systematic review and meta-analysis, EVT was associated with favorable outcome and decreased mortality in patients with BAO up to 24 hours from stroke symptoms compared to MM. The treatment effect in BAO patients with NIHSS <10 was less certain. Further studies are of interest to evaluate the efficacy of EVT in basilar occlusion patients with milder symptoms.