Study on transmission error and torsional stiffness of RV reducer under wear

Ronghua Zhang,Jianxing Zhou,Zheng Wei 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.8

In order to discuss the influence of wear dynamic evolution on the degradation of core transmission performance, transmission error and meshing torsional stiffness of RV reducer, taking BX-40E reducer as the research object, based on Langkali-Nikraves contact force model and Archard wear theory, the wear coefficients with different position conditions were obtained through equivalent wear experiments. The RV transmission dynamic model considering wear, meshing stiffness, meshing force, meshing tooth pairs and transmission error linkage was established by using centralized parameter method and dynamic subsystem method. Compared with the traditional tooth profile wear simulation, which distribution and size of the wear depth curves were more and more different with wear dynamic evolution, theoretically concluded that the dynamic update of wear coefficient is necessary and correct for the accurate simulation of tooth surface wear. The transmission error shows a "double hump" distribution mapped to the wear depth of the tooth profile, and deteriorates with the wear accumulation. The equivalent torsional stiffness of cycloid pin teeth decreases piecewise approximately linearly due to wear. In the previous stage, the reduction rate is small because the tooth detachment first occurs at the tooth top and root, and the single tooth torsional stiffness near the tooth top and root is smaller. The research results provide a new idea and theoretical basis for improving the transmission accuracy, stability holding ability, wear reduction and life extension of RV reducer.

Water film covering characteristic on horizontal fuel rod under impinging cooling condition

Zhang Penghui,Wang Bowei,Chen Ronghua,Su G.H.,Tian Wenxi,Qiu Suizheng 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.11

Jet impinging device is designed for decay heat removal on horizontal fuel rods in a low temperature heating reactor. An experimental system with a fuel rod simulator is established and experiments are performed to evaluate water film covering capacity, within 0.0287e0.0444 kg/ms mass flow rate, 0 e164.1 kW/m2 heating flux and 13.8e91.4C feeding water temperature. An effective method to obtain the film coverage rate by infrared equipment is proposed. Water film flowing patterns are recoded and the film coverage rates at different circumference angles are measured. It is found the film coverage rate decreases with heating flux during single-phase convection, while increases after onset of nucleate boiling. Besides, film coverage rate is found affected by Marangoni effect and film accelerating effect, and surface wetting is significantly facilitated by bubble behavior. Based on the observed phenomenon and physical mechanism, dry-out depth and initial dry-out rate are proposed to evaluate film covering potential on a heating surface. A model to predict film coverage rate is proposed based on the data. The findings would have reliable guide and important implications for further evaluation and design of decay heat removal system of new reactors, and could be helpful for passive containment cooling research.

A Visualization System for Multiple Heterogeneous Network Security Data and Fusion Analysis

( Sheng Zhang ),( Ronghua Shi ),( Jue Zhao ) 한국인터넷정보학회 2016 KSII Transactions on Internet and Information Syst Vol.10 No.6

Owing to their low scalability, weak support on big data, insufficient data collaborative analysis and inadequate situational awareness, the traditional methods fail to meet the needs of the security data analysis. This paper proposes visualization methods to fuse the multi-source security data and grasp the network situation. Firstly, data sources are classified at their collection positions, with the objects of security data taken from three different layers. Secondly, the Heatmap is adopted to show host status; the Treemap is used to visualize Netflow logs; and the radial Node-link diagram is employed to express IPS logs. Finally, the Labeled Treemap is invented to make a fusion at data-level and the Time-series features are extracted to fuse data at feature-level. The comparative analyses with the prize-winning works prove this method enjoying substantial advantages for network analysts to facilitate data feature fusion, better understand network security situation with a unified, convenient and accurate mode.

Drug-Loaded Chondroitin Sulfate Microspheres Generated from Microfluidic Electrospray for Wound Healing

Hongzhen Zhang,Ronghua Xu,Zuowen Yin,Jun Yu,Ning Liang,Geng Qian 한국고분자학회 2022 Macromolecular Research Vol.30 No.1

Wound treatment is an important issue and poses a critical challenge for healthcare systems. It is of great significance to develop materials for wound repair and regeneration. Herein, we presented a kind of novel drug-loaded methacryloyl chondroitin sulfate (CSMA) microspheres for promoting the wound healing process. The CSMA droplets were generated from microfluidic electrospray and polymerized with ultraviolet light. With further freeze-drying and drug uploading, the drugloaded CSMA microspheres were achieved. The prepared microspheres exhibited excellent biocompatibility, and the following animal experiments indicated they could promote wound healing significantly. This study opens the door to drug-loaded CSMA microspheres for wound healing applications.

Segment Training Based Individual Channel Estimation for Multi-pair Two-Way Relay Network with Power Allocation

( Xiandeng He ),( Ronghua Zhou ),( Nan Chen ),( Shun Zhang ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.2

In this paper, we design a segment training based individual channel estimation (STICE) scheme for the classical two-way relay network (TWRN) with multi-pair sources (MPS) and amplify-and-forward (AF). We adopt the linear minimum mean square error (LMMSE) channel estimator to minimize the mean square error (MSE) without channel estimation error, where the optimal power allocation strategy from the relay for different sources is obtained. Then the MSE gains are given with different source pairs among the proposed power allocation scheme and the existing power allocation schemes. Numerical results show that the proposed method outperforms the existing ones.

Cloning of porcine chemerin, ChemR23 and GPR1 and their involvement in regulation of Lipogenesis

( Jianfeng Huang ),( Jian Zhang ),( Ting Lei ),( Xiaodong Chen ),( Yan Zhang ),( Lulu Zhou ),( An Yu ),( Zhilong Chen ),( Ronghua Zhou ),( Zaiqing Yang ) 생화학분자생물학회 (구 한국생화학분자생물학회) 2010 BMB Reports Vol.43 No.7

Chemerin is a novel adipokine which is abundant in adipose tissue to promote adipocyte differentiation and with significant relativity to BMI and insulin sensitivity. We report here the molecular characterization of porcine chemerin and its receptors ChemR23 and GPR1, as well as their transcriptional regulation during lipogenesis. Chemerin was mainly expressed in liver, intestine, kidney and adipose tissue, consistent with the expression pattern of GPR1, but not ChemR23, which was predominantly present in spleen and temperately in adipose tissue. We further investigated the lipogenesis-related transcriptional activation of PPARγ and KLF15 on chemerin and its receptors. The data showed that KLF15, but not PPARγ, can up-regulate the mRNA level of chemerin, ChemR23 and GPR1, which was consistent with the results of luciferase assay that confirmed the effect of KLF15 on ChemR23 promoter. Taken together, our data provide basic molecular information for the further investigation on the function of chemerin in lipogenesis. [BMB reports 2010; 43(7): 491-498]

Enhance photoelectric efficiency of PV by optical-thermal management of nanofilm reflector

Liang, Huaxu,Wang, Baisheng,Su, Ronghua,Zhang, Ao,Wang, Fuqiang,Shuai, Yong Techno-Press 2022 Advances in nano research Vol.13 No.5

Crystalline silicon photovoltaic cells have advantages of zero pollution, large scale and high reliability. A major challenge is that sunlight wavelength with photon energy lower than semiconductor band gap is converted into heat and increase its temperature and reduce its conversion efficiency. Traditional cooling PV method is using water flowing below the modules to cool down PV temperature. In this paper, the idea is proposed to reduce the temperature of the module and improve the energy conversion efficiency of the module through the modulation of the solar spectrum. A spectrally selective nanofilm reflector located directly on the surface of PV is designed, which can reflect sunlight wavelength with low photon energy, and even enhance absorption of sunlight wavelength with high photon energy. The results indicate that nanofilm reflector can reduce spectral reflectivity integral from 9.0% to 6.93% in 400~1100 nm wavelength range, and improve spectral reflectivity integral from 23.1% to 78.34% in long wavelength range. The nanofilm reflector can reduce temperature of PV by 4.51℃ and relatively improved energy conversion efficiency of PV by 1.25% when solar irradiance is 1000 W/m². Furthermore, the nanofilm reflector is insensitive in sunlight's angle and polarization state, and be suitable for high irradiance environment.

Antidepressant-like effect of ginsenoside Rb1 on potentiating synaptic plasticity via the miR-134emediated BDNF signaling pathway in a mouse model of chronic stress-induced depression

Guoli Wang,Tianyue An,Cong Lei,Xiaofeng Zhu,Li Yang,Lianxue Zhang,Ronghua Zhang 고려인삼학회 2022 Journal of Ginseng Research Vol.46 No.3

Brain-derived neurotrophic factor (BDNF)etropomyosin-related kinase B (TrkB) plays acritical role in the pathogenesis of depression by modulating synaptic structural remodeling and functional transmission. Previously, we have demonstrated that the ginsenoside Rb1 (Rb1) presents a novelantidepressant-like effect via BDNFeTrkB signaling in the hippocampus of chronic unpredictable mildstress (CUMS)-exposed mice. However, the underlying mechanism through which Rb1 counteractsstress-induced aberrant hippocampal synaptic plasticity via BDNFeTrkB signaling remains elusive. Methods: We focused on hippocampal microRNAs (miRNAs) that could directly bind to BDNF and areregulated by Rb1 to explore the possible synaptic plasticity-dependent mechanism of Rb1, which affordsprotection against CUMS-induced depression-like effects. Results: Herein, we observed that brain-specific miRNA-134 (miR-134) could directly bind to BDNF 30UTRand was markedly downregulated by Rb1 in the hippocampus of CUMS-exposed mice. Furthermore, thehippocampusetargeted miR-134 overexpression substantially blocked the antidepressant-like effects ofRb1 during behavioral tests, attenuating the effects on neuronal nuclei-immunoreactive neurons, thedensity of dendritic spines, synaptic ultrastructure, long-term potentiation, and expression of synapseassociated proteins and BDNFeTrkB signaling proteins in the hippocampus of CUMS-exposed mice. Conclusion: These data provide strong evidence that Rb1 rescued CUMS-induced depression-like effectsby modulating hippocampal synaptic plasticity via the miR-134-mediated BDNF signaling pathway.