Structural configurations and dynamic performances of flexible riser with distributed buoyancy modules based on FEM simulations

Chen Weimin,Guo Shuangxi,Li Yilun,Gai Yuxin,Shen Yijun 대한조선학회 2021 International Journal of Naval Architecture and Oc Vol.13 No.1

Flexible risers are usually used as conveying systems to bring ocean resources from sea bed up to onshore. Under ocean environments, risers need to bear complex loads and it is crucial to comprehensively examine riser's configurations and to analyze structural dynamic performances under excitation of bottom vehicle motions, to guarantee structural safe operation and required service lives. In this study, considering a saddle-shaped riser, the influences of some important design parameters, including installation position of buoyancy modules, buoyancy ratio and motion of mining vehicle, on riser's configuration and response are carefully examined. Through our FEM simulations, the spatial distributions of structural tensions and curvatures along of riser length, under different configurations, are compared. Then, the impacts of mining vehicle motion on riser dynamic response are discussed, and structural tolerance performance is assessed. The results show that modules installation position and buoyancy ratio have significant impacts on riser configurations. And, an appropriate riser configuration is obtained through comprehensive analysis on the modules positions and buoyancy ratios. Under this proposed configuration, the structural tension and curvature could moderately change with buoyancy modules and bottom-end conditions, in other words, the proposed saddle-shaped riser has a good tolerance performance to various load excitations.

Tri-metal-based hollow nanorods-on-microrod arrays as efficient water splitting electrocatalysts

Jianzhi Wang,Hongliang Yu,Xianming Wang,Chen Chen,Shuaijie Li,Ning Cai,Weimin Chen,Yanan Xue,Hui Li,Faquan Yu 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.105 No.-

Constructing ordered hierarchical porous electrocatalysts while maintaining their high efficiency and stabilityfor oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is highly desirable butstill remains challenging. Herein, hierarchical tri-metal-based hollow nano/micro rod-on-rod array structures,including hydroxides and phosphates, are vertically grown on Cu foam by the cation-exchangingand anion exchanging approaches. Such ordered porous architecture, providing multi metal center, regularinterconnection of macropore channel, large electrochemical surface area, small charge-transferresistance, efficient mass transport and electron transfer for overall water splitting in alkaline media. These obtained hydroxide OER catalysts (CoMn LDH@Cu(OH)2/CF) and phosphide HER catalysts(CoMnP@Cu3P/CF) exhibited low onset potential, low Tafel slope, and prominent durability. Such excellentperformance, ordered porous structure and simple preparation methods indicate that this study providesa new strategy for assembling promising catalysts for water splitting and other applications.

Genetic diversity and genetic differentiation of Megalobrama populations inferred by mitochondrial markers

Chen Jing,Wang Weimin 한국유전학회 2021 Genes & Genomics Vol.43 No.10

Background Megalobrama is economically one of the most important freshwater fsh genera in China. However, phylogenetic relationships among M. amblycephala, M. skolkovii, M. hofmanni and M. pellegrini remain unresolved. Objective To explore the genetic diversity and phylogenetic relationship of Megalobrama populations belonging to all four species. Methods The concatenated sequences of mitochondrial cytochrome b (Cytb) and control region (CR) were used to analyze the genetic variation, genetic diferentiation and population expansion of 15 Megalobrama populations. Results The study showed that haplotype diversity and nucleotide diversity of M. hofmanni and M. skolkovii were high, and that M. hofmanni was the most genetically divergent of the four species. Haplotype network analysis revealed that M. hofmanni and M. amblycephala formed a monophyletic group each, while M. skolkovii and M. pellegrini clustered together. There was a high genetic diferentiation among the four Megalobrama species, and genetic distance among populations was not afected by geographical distance. Additionally, the results indicated that there was gene fow between the Liangzi Lake (LZL) population and Jinsha River Reservoir (JS) population. Also, Zhaoqing (ZQ) population of M. hofmanni might have experienced a population expansion. Conclusion Our study verifes genetic diversity and diferentiation of Megalobrama populations, and these fndings will represent a signifcant contribution to the conservation and utilization of germplasm resources of Megalobrama.

Exploring the Impact of Surface Roughness on Tribological Properties at Micro and Macro Scales

Chen Wang,Wenli Wang,Kai Le,Shusheng Xu,Weimin Liu 한국표면공학회 2023 한국표면공학회 학술발표회 초록집 Vol.2023 No.11-1

LncRNA CRNDE Promotes the Progression of B-cell Precursor Acute Lymphoblastic Leukemia by Targeting the miR-345-5p/CREB Axis

Weimin Wang,Feifei Wu,Ping Ma,Silin Gan,Xue Li,Li Chen,Ling Sun,Hui Sun,Zhongxing Jiang,Feng Guo 한국분자세포생물학회 2020 Molecules and cells Vol.43 No.8

The imbalance between the proliferation and apoptosis of B-cell precursors is an important contributor to the pathogenesis of B-cell precursor acute lymphoblastic leukemia (BCP-ALL), while its specific regulatory mechanism remains perplexing. This study aimed to expound the underlying mechanism of the proliferation and apoptosis of BCP-ALL cells from the perspective of non-coding RNA. In this study, long non-coding RNA colorectal neoplasia differentially expressed (LncRNA CRNDE) was upregulated in the bone marrow of BCP-ALL patients and BCP-ALL cell lines (NALM-6 and RS4;11). Functionally, LncRNA CRNDE knockdown restrained cell proliferation and boosted cell apoptosis in NALM-6 and RS4;11 cells. The subsequent investigation confirmed that LncRNA CRNDE bound to miR-345-5p and negatively regulated miR-345-5p expression. The overexpression of miR-345-5p suppressed cell proliferation and boosted cell apoptosis in NALM-6 and RS4;11 cells. Further experiments revealed that miR-345-5p downregulated cyclic AMP response element-binding protein (CREB) expression by targeting its mRNA directly. CREB overexpression reversed the effect of miR-345-5p mimic on cell proliferation and apoptosis in NALM-6 and RS4;11 cells. Finally, in vivo experiments showed that LncRNA CRNDE knockdown prolonged the survival of mice xenotransplanted with NALM-6 cells. In conclusion, LncRNA CRNDE upregulated CREB expression by suppressing miR-345-5p, thus promoting cell proliferation and reducing cell apoptosis in BCP-ALL.

The stacked over-expression of FPS, CYP71AV1 and CPR genes leads to the increase of artemisinin level in Artemisia annua L.

Yunfei Chen,Qian Shen,Yueyue Wang,Tao Wang,Shaoyan Wu,Ling Zhang,Xu Lu,Fangyuan Zhang,Weimin Jiang,Bo Qiu,Erdi Gao,Xiaofen Sun,Kexuan Tang 한국식물생명공학회 2013 Plant biotechnology reports Vol.7 No.3

Artemisinin is an endoperoxide sesquiterpenelactone isolated from the aerial parts of Artemisia annua L.,and is presently the most potent anti-malarial drug. Owingto the low yield of artemisinin from A. annua as well as thewidespread application of artemisinin-based combinationtherapy recommended by the World Health Organization,the global demand for artemisinin is substantially increasingand is therefore rendering artemisinin in short supply. An economical way to increase artemisinin production is toincrease the content of artemisinin in A. annua. In thisstudy, three key genes in the artemisinin biosynthesispathway, encoding farnesyl diphosphate synthase, amorpha-4, 11-diene C-12 oxidase and its redox partner cytochromeP450 reductase, were over-expressed in A. annuathrough Agrobacterium-mediated transformation. Thetransgenic lines were confirmed by Southern blotting andthe over-expressions of the genes were demonstrated byreal-time PCR assays. The HPLC analysis showed that theartemisinin contents in transgenic lines were increasedsignificantly, with the highest one found to be 3.6-foldhigher (2.9 mg/g FW) than that of the control. Theseresults demonstrate that multigene engineering is aneffective way to enhance artemisinin content in A. annua.

Master-Slave Control of an Intention-Actuated Exoskeletal Robot for Locomotion and Lower Extremity Rehabilitation

Gao Huang,Weimin Zhang,Fei Meng,Zhangguo Yu,Xuechao Chen,Marco Ceccarelli,Qiang Huang 한국정밀공학회 2018 International Journal of Precision Engineering and Vol.19 No.7

In this paper, a master-slave control system is proposed and applied in an intention-actuated exoskeletal robot to assist user locomotion and lower extremity rehabilitation simultaneously. In particular, to increase users’ sense of participation, the motion of the exoskeleton and the wheelchair, which is denoted as slave motion in this study, is actuated by the user’s intention, which is denoted as master motion and thus makes patients feel that they are moving the wheelchair. This master-slave motion control system can help to eliminate patients’ fear of medical apparatus and instruments. The bicycling motion actuated by one motor is implemented to realize the rehabilitation motion exercise. Experimental results validate a position-force control strategy for the exoskeleton motors, and show that the proposed method can help users to move around and to exercise their legs simultaneously and effectively.

THE RADIO PROPERTIES OF RADIO-LOUD NARROW-LINE SEYFERT 1 GALAXIES ON PARSEC SCALES

Gu, Minfeng,Chen, Yongjun,Komossa, S.,Yuan, Weimin,Shen, Zhiqiang,Wajima, Kiyoaki,Zhou, Hongyan,Zensus, J. A. IOP Publishing 2015 The Astrophysical journal Supplement series Vol.221 No.1

<P>We present the detection of the compact radio structures of 14 radio-loud narrow-line Seyfert 1 (NLS1) galaxies from Very Long Baseline Array (VLBA) observations at 5 GHz performed in 2013. While 50% of the sources of our sample show a compact core only, the remaining 50% exhibit a core-jet structure. The measured brightness temperatures of the cores range from 10(8.4) to 10(11.4) K with a median value of 10(10.1) K, indicating that the radio emission is from non-thermal jets, and that, likely, most sources are not strongly beamed, thus implying a low jet speed in these radio-loud NLS1 galaxies. In combination with archival data taken at multiple frequencies, we find that seven sources show flat or even inverted radio spectra, while steep spectra are revealed in the remaining seven objects. Although all of these sources are very radio-loud with R > 100, their jet properties are diverse in terms of their milliarcsecond (mas) scale (parsec scale) morphology and their overall radio spectral shape. The evidence for slow jet speeds (i.e., less relativistic jets), in combination with the low kinetic/radio power, may offer an explanation for the compact VLBA radio structure in most sources. The mildly relativistic jets in these high accretion rate systems are consistent with a scenario where jets are accelerated from the hot corona above the disk by the magnetic field and the radiation force of the accretion disk. Alternatively, a low jet bulk velocity can be explained by low spin in the Blandford-Znajek mechanism.</P>

An improvement on the concrete exothermic models considering self-temperature duration

Zhenyang Zhu,Weimin Chen,Sheng Qiang,Guoxin Zhang,Youzhi Liu 사단법인 한국계산역학회 2017 Computers and Concrete, An International Journal Vol.19 No.6

Based on the Arrhenius equations, several hydration exothermic models that precisely calculate the influence of concrete’s self-temperature duration on its hydration exothermic rate have been presented. However, the models’ convergence is difficult to achieve when applied to engineering projects, especially when the activation energy of the Arrhenius equation is precisely considered. Thus, the models’ convergence performance should be improved. To solve this problem and apply the model to engineering projects, the relationship between fast iteration and proper expression forms of the adiabatic temperature rise, the coupling relationship between the pipe-cooling and hydration exothermic models, and the influence of concrete’s self-temperature duration on its mechanical properties were studied. Based on these results, the rapid convergence of the hydration exothermic model and its coupling with pipe-cooling models were achieved. The calculation results for a particular engineering project show that the improved concrete hydration exothermic model and the corresponding mechanical model can be suitably applied to engineering projects.

Gene expression and promoter methylation of porcine uncoupling protein 3 gene

Ruiyi Lin,Weimin Lin,Qiaohui Chen,Jianchao Huo,Yuping Hu,Junxiao Ye,Jingya Xu,Tianfang Xiao 아세아·태평양축산학회 2019 Animal Bioscience Vol.32 No.2

Objective: Uncoupling protein 3 gene (UCP3) is a candidate gene associated with the meat quality of pigs. The aim of this study was to explore the regulation mechanism of UCP3 expression and provide a theoretical basis for the research of the function of porcine UCP3 gene in meat quality. Methods: Bisulfite sequencing polymerase chain reaction (PCR) and quantitative real-time PCR (Q-PCR) were used to analyze the methylation of UCP3 5′-flanking region and UCP3 mRNA expression in the adipose tissue or skeletal muscle of three pig breeds at different ages (1, 90, 210-day-old Putian Black pig; 90-day-old Duroc; and 90-day-old Dupu). Results: Results showed that two cytosine-guanine dinucleotide (CpG) islands are present in the promoter region of porcine UCP3 gene. The second CpG island located in the core promoter region contained 9 CpG sites. The methylation level of CpG island 2 was lower in the adipose tissue and skeletal muscle of 90-day-old Putian Black pigs compared with 1-day-old and 210-day-old Putian Black pigs, and the difference also existed in the skeletal muscle among the three 90-day-old pig breeds. Furthermore, the obvious changing difference of UCP3 mRNA expression was observed in the skeletal muscle of different groups. However, the difference of methylation status and expression level of UCP3 gene was not significant in the adipose tissue. Conclusion: Our data indicate that UCP3 mRNA expression level was associated with the methylation status of UCP3 promoter in the skeletal muscle of pigs.