http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Effects of rolling-cutting processing parameters on micro-grooved strips forming
Baoyu Zhang,Xianqi Fan,Guocheng Shi,Yang Zhou,Di He,Wenjun Deng 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.1
High heat flux density in the micro-electronics field urges the demand for functional surface for heat transfer. Micro-grooved surface is the classical heat transfer surface because of the larger specific area and better inducement of turbulence. A novel micro-grooved surface manufacturing process, the rolling-cutting process, is proposed to produce microgrooved strips. Experiments are conducted to analyze the influence of processing parameters on the strips forming. The optimal combination of processing parameters is given to attain the micro-grooved strips with higher fins height and thinner base thickness. Additionally, the obtained strips are of three-dimensional structures with serrated bulges at the top. The difference between the material flow of serrated bulges and strip base is discussed, and the forming of serrated bulges is mainly due to inhomogeneous sinuous material flow.
Performance of Gas-Liquid Upstream Pumping Spiral Groove Mechanical Face Seals
Baoyu Zhang,Weibing Wang,Tiebo Sun,Ping Li 한국유체기계학회 2024 International journal of fluid machinery and syste Vol.17 No.1
Upstream pumping spiral grooves provides an effective way to realize design of mechanical seals with long service life as well as low leakage rate, which largely lies on precise design of spiral grooves under gas-liquid lubricating boundary conditions. The originality of this paper is to consider the gas phase pressure boundary in order to be suitable for more complex gas-liquid seal analysis. An numerical analysis of performance of upstream pumping spiral groove mechanical face seals is carried outunder gas-liquid boundary conditions. Opening force and leakage rate are calculated taking account of gas-liquid fluid medium boundary conditions as well as cavitation effect. The results show that the opening force and leakage rate decrease obviously under gas-liquid boundary conditions, compared with the full liquid boundary conditions, exceeding 50% in degree. Besides, the groove parameters such as spiral angle, slotting ratio and groove number present obvious and complex influence on the opening force and leakage rate. This research may provide the reasonable basis for the design of upstream pumping spiral groove mechanical face seals.
Baoyu Huang,Yongxiang Zhang,Lei Zhao,Hao Chen 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.5
Aiming at the problem that the effectiveness of impulse feature enhancement (IFE) depends on the duration of high-level (or low-level) K and the number of high-level L, we regard a segmented impulse norm as the fitness function and combine it with the whale optimization algorithm to select the optimal parameters adaptively. Time-frequency joint noise reduction (TFJNR) is also proposed to suppress the noise components in the signal. Simulation and experimental results of rolling bearings indicate that the proposed algorithm can rapidly select the optimal parameters K and L to ensure the performance of IFE, while TFJNR has the ability to suppress the noise components in the signal. Fast kurtogram, empirical mode decomposition, and fast spectral correlation are also used for comparison. The results highlight the performance of the proposed algorithm.
Genmeng Yang,Juan Li,Yanxia Peng,Baoyu Shen,Yuanyuan Li,Liu Liu,Chan Wang,Yue Xu,Shucheng Lin,Shuwei Zhang,Yi Tan,Huijie Zhang,Xiaofeng Zeng,Qi Li,Gang Lu 고려인삼학회 2022 Journal of Ginseng Research Vol.46 No.3
This study investigates the effects of ginsenoside Rb1 (GsRb1) on methamphetamine (METH)-induced toxicity in SH-SY5Y neuroblastoma cells and METH-induced conditioned place preference (CPP)in adult Sprague-Dawley rats. It also examines whether GsRb1 can regulate these effects through theNR2B/ERK/CREB/BDNF signaling pathways. Methods: SH-SY5Y cells were pretreated with GsRb1 (20 mM and 40 mM) for 1 h, followed by METHtreatment (2 mM) for 24 h. Rats were treated with METH (2 mg/kg) or saline on alternating days for 10days to allow CPP to be examined. GsRb1 (5, 10, and 20 mg/kg) was injected intraperitoneally 1 h beforeMETH or saline. Western blot was used to examine the protein expression of NR2B, ERK, P-ERK, CREB, PCREB, and BDNF in the SH-SY5Y cells and the rats' hippocampus, nucleus accumbens (NAc), and prefrontal cortex (PFC). Results: METH dose-dependently reduced the viability of SH-SY5Y cells. Pretreatment of cells with 40mM of GsRb1 increased cell viability and reduced the expression of METH-induced NR2B, p-ERK, p-CREBand BDNF. GsRb1 also attenuated the expression of METH CPP in a dose-dependent manner in rats. Further, GsRb1 dose-dependently reduced the expression of METH-induced NR2B, p-ERK, p-CREB, andBDNF in the PFC, hippocampus, and NAc of rats. Conclusion: GsRb1 regulated METH-induced neurotoxicity in vitro and METH-induced CPP through theNR2B/ERK/CREB/BDNF regulatory pathway. GsRb1 could be a therapeutic target for treating METHinduced neurotoxicity or METH addiction.
Pengfei Gao,Zhimin Cheng,Meng Li,Ningfang Zhang,Baoyu Le,Wanfeng Zhang,Pengkang Song,Xiaohong Guo,Bugao Li,Guoqing Cao 아세아·태평양축산학회 2019 Animal Bioscience Vol.32 No.8
Objective: The aim of this study was to select the candidate genes affecting meat quality and preliminarily explore the related molecular mechanisms in the Mashen pig. Methods: The present study explored genetic factors affecting meat quality in the Mashen pig using RNA sequencing (RNA-Seq). We sequenced the transcriptomes of 180-day-old Mashen and Large White pigs using longissimus dorsi to select differentially expressed genes (DEGs). Results: The results indicated that a total of 425 genes were differentially expressed between Mashen and Large White pigs. A gene ontology enrichment analysis revealed that DEGs were mainly enriched for biological processes associated with metabolism and muscle development, while a Kyoto encyclopedia of genes and genomes analysis showed that DEGs mainly participated in signaling pathways associated with amino acid metabolism, fatty acid metabolism, and skeletal muscle differentiation. A MCODE analysis of the protein-protein interaction network indicated that the four identified subsets of genes were mainly associated with translational initiation, skeletal muscle differentiation, amino acid metabolism, and oxidative phosphorylation pathways. Conclusion: Based on the analysis results, we selected glutamic-oxaloacetic transaminase 1, malate dehydrogenase 1, pyruvate dehydrogenase 1, pyruvate dehydrogenase kinase 4, and activator protein-1 as candidate genes affecting meat quality in pigs. A discussion of the related molecular mechanisms is provided to offer a theoretical basis for future studies on the improvement of meat quality in pigs.
Surface Modification with Pluronic P123 Enhances Transfection Efficiency of PAMAM Dendrimer
Xiang Wang,Shen Gao,Xin Wu,Wei Fan,Baoyue Ding,Xiaoyu Wang,Wei Zhang,Xueying Ding,Jing Gao,Quangang Zhu,Jiyong Liu,Zhen Cai 한국고분자학회 2012 Macromolecular Research Vol.20 No.2
To improve gene delivery efficiency and decrease cytotoxicity of polyamidoamine (PAMAM) polymers,P123-g-PAMAM was synthesized by modifying PAMAM with pluronic P123. The structure of the synthesized polymers was analyzed using proton nuclear magnetic resonance. The polymers were able to self-assemble with DNA,forming nanometer-scale complexes. Particle size measurement confirmed that the mean diameter of the polyplexes was 100-250 nm. The cytotoxicity and transfer efficiency were measured and compared with those of PEI and PAMAM. All of the polyplexes showed significantly low cytotoxicity in the MCF-7, HepG2, and 293T cell lines. In addition, the low level of P123 grafting to PAMAM showed significantly higher transfection efficiency than unmodified PAMAM at the optimal N/P ratio. These results suggest that P123-ylated PAMAM may prove as a useful carrier for gene delivery.