Research on the motion characteristics of a trans-media vehicle when entering water obliquely at low speed

Li, Yong-li,Feng, Jin-fu,Hu, Jun-hua,Yang, Jian The Society of Naval Architects of Korea 2018 International Journal of Naval Architecture and Oc Vol.10 No.2

This paper proposes a single control strategy to solve the problem of trans-media vehicle difficult control. The proposed control strategy is just to control the vehicle's air navigation, but not to control the underwater navigation. The hydrodynamic model of a vehicle when entering water obliquely at low speed has been founded to analyze the motion characteristics. Two methods have been used to simulate the vehicle entering water in the same condition: numerical simulation method and theoretical model solving method. And the results of the two methods can validate the hydrodynamic model founded in this paper. The entering water motion in the conditions of different velocity, different angle, and different attack angle has been simulated by this hydrodynamic model and the simulation has been analyzed. And the change rule of the vehicle's gestures and position when entering water has been obtained by analysis. This entering water rule will guide the follow-up of a series of research, such as the underwater navigation, the exiting water process and so on.

Citricoccus alkalitolerans sp. nov., a novel actinobacterium isolated from a desert soil in Egypt

Li, Wen-Jun,Chen, Hua-Hong,Zhang, Yu-Qin,Kim, Chang-Jin,Park, Dong-Jin,Lee, Jae-Chan,Xu, Li-Hua,Jiang, Cheng-Lin Microbiology Society 2005 International journal of systematic and evolutiona Vol.55 No.1

<P>An actinobacterium, strain YIM 70010<SUP>T</SUP>, which was isolated from a desert soil sample collected in Egypt, was subjected to a polyphasic taxonomy study. The organism was alkalitolerant and its optimum growth occurred at pH 8·0-9·0. The isolate contained chemotaxonomic markers that were characteristic of the genus <I>Citricoccus</I>, i.e. the peptidoglycan type Lys-Gly-Glu (variation A4<I>α</I>), the predominant menaquinone MK-9(H2) and a polar lipid profile consisting of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol and two unknown glycolipids. The major fatty acids were anteiso-C15 : 0 and iso-C15 : 0. The G+C content of the genomic DNA was 63·8 mol%. Strain YIM 70010<SUP>T</SUP> exhibited a 16S rRNA gene sequence similarity of 99·6 % and DNA-DNA relatedness value of 56 % with <I>Citricoccus muralis</I> DSM 14442<SUP>T</SUP>. The phenotypic characteristics and DNA-DNA relatedness data indicate that strain YIM 70010<SUP>T</SUP> can be distinguished from <I>C. muralis</I> (DSM 14442<SUP>T</SUP>). Therefore, on the basis of the polyphasic taxonomic data presented, a novel species of the genus <I>Citricoccus</I>, <I>Citricoccus alkalitolerans</I> sp. nov. (type strain, YIM 70010<SUP>T</SUP>=CCTCC AA 203008<SUP>T</SUP>=DSM 15665<SUP>T</SUP>=KCTC 19012<SUP>T</SUP>) is proposed.</P>

Dynamic stiffness matrix of an axially loaded slender double-beam element

Li Jun,Hua Hongxing,Li Xiaobin 국제구조공학회 2010 Structural Engineering and Mechanics, An Int'l Jou Vol.35 No.6

The dynamic stiffness matrix is formulated for an axially loaded slender double-beam element in which both beams are homogeneous, prismatic and of the same length by directly solving the governing differential equations of motion of the double-beam element. The Bernoulli-Euler beam theory is used to define the dynamic behaviors of the beams and the effects of the mass of springs and axial force are taken into account in the formulation. The dynamic stiffness method is used for calculation of the exact natural frequencies and mode shapes of the double-beam systems. Numerical results are given for a particular example of axially loaded double-beam system under a variety of boundary conditions, and the exact numerical solutions are shown for the natural frequencies and normal mode shapes. The effects of the axial force and boundary conditions are extensively discussed.

PREPARATION OF SiO2 HIERARCHICAL NANOSTRUCTURE VIA CATALYST-FREE THERMAL EVAPORATION METHOD

JUN MA,GONG-YI LI,Xiao-dong Li,GANG PENG,YI-HE LI,HUA-YU CHEN 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2013 NANO Vol.8 No.4

A novel hierarchical nanostructure of SiO2 nanowires standing on SiO2 microwires was synthesized through a catalyst-free thermal evaporation method in nitrogen atmosphere. The SiO2 nanowires have an average diameter of 100 nm and length of 2 μm, while the diameter of the SiO2 microwires is around 10 μm and the length is hundreds of micrometers. The photoluminescence spectrum of the SiO2 hierarchical nanostructure shows stable blue and green emission at 442 nm and 533 nm, respectively. An oxygen-assisted three-step growth mechanism was suggested to interpret the growth of the SiO2 hierarchical nanostructure.

A Study on Cutting and Tribology Performances of TiN and TiAlN Coated Tools

Li, Hua-Ying,He, Hui-Bo,Han, Wen-Qiang,Yang, Jun,Gu, Tao,Li, Yuan-ming,Lyu, Sung-Ki Korean Society for Precision Engineering 2015 International Journal of Precision Engineering and Vol.16 No.4

TiN and TiAlN coatings were deposited on the surface of AISI 5140 steel and cemented carbide YT15 by magnetron sputtering technique (MSP). The reciprocating sliding tests of TiN and TiAIN coatings on the surface of AISI 5140 steel were performed to investigate the friction coefficients of coatings affected by various normal loads with friction pair of 304 stainless steel balls. Dry machining tests on AISI 5140 hardened steel were carried out with the TiN and TiAlN coated tools on a CA6140A lathe. The effects of cutting speed on cutting forces and surface roughness of TiN and TiAlN coated tools were obtained and analyzed to assess the cutting performance of coated tools. The microcosmic micrographs of wear areas of coated tools were observed and investigated by scanning electron microscope and energy dispersive spectrum. The results show that the friction coefficients of TiN coatings are lower than that of TiAlN coatings. The cutting force of TiAlN coated tool decreases and flank wear resistance enhances in comparison with TiN coated tool. The wear form and mechanisms of TiN coated tool are mainly crater wear on the rake face and adhesive wear and abrasive wear on the flank face. The wear form and mechanisms of TiAlN coated tool are mainly adhesive wear, the breakage of cutting edge and the damage of tip, accompanied with diffusion and oxidation wear.

Molecular and Biochemical Characterization of a Novel Intracellular Low-Temperature-Active Xylanase

( Jun Pei Zhou,),( Yan Yan Dong ),( Xiang Hua Tang ),( Jun Jun Li ),( Bo Xu ),( Qian Wu ),( Ya Jie Gao ),( Lu Pan ),( Zun Xi Huang ) 한국미생물 · 생명공학회 2012 Journal of microbiology and biotechnology Vol.22 No.4

A 990 bp full-length gene (xynAHJ2) encoding a 329- residue polypeptide (XynAHJ2) with a calculated mass of 38.4 kDa was cloned from Bacillus sp. HJ2 harbored in a saline soil. XynAHJ2 showed no signal peptide, distinct amino acid stretches of glycoside hydrolase (GH) family 10 intracellular endoxylanases, and the highest amino acid sequence identity of 65.3% with the identified GH 10 intracellular mesophilic endoxylanase iM-KRICT PX1-Ps from Paenibacillus sp. HPL-001 (ACJ06666). The recombinant enzyme (rXynAHJ2) was expressed in Escherichia coli and displayed the typical characteristics of low-temperatureactive enzyme (exhibiting optimum activity at 35 o C, 62% at 20 o C, and 38% at 10 o C; thermolability at ≥45 o C). Compared with the reported GH 10 low-temperature-active endoxylanases, which are all extracellular, rXynAHJ2 showed low amino acid sequence identities (<45%), low homology (different phylogenetic cluster), and difference of structure (decreased amount of total accessible surface area and exposed nonpolar accessible surface area). Compared with the reported GH 10 intracellular endoxylanases, which are all mesophilic and thermophilic, rXynAHJ2 has decreased numbers of arginine residues and salt bridges, and showed resistance to Ni 2+ , Ca 2+ , or EDTA at 10 mM final concentration. The above mechanism of structural adaptation for low-temperature activity of intracellular endoxylanase rXynAHJ2 is different from that of GH 10 extracellular low-temperature-active endoxylanases. This is the first report of the molecular and biochemical characterizations of a novel intracellular low-temperatureactive xylanase.

Isolation, Culture and Identification of Porcine Skeletal Muscle Satellite Cells

Li, Bo-jiang,Li, Ping-hua,Huang, Rui-hua,Sun, Wen-xing,Wang, Han,Li, Qi-fa,Chen, Jie,Wu, Wang-jun,Liu, Hong-lin Asian Australasian Association of Animal Productio 2015 Animal Bioscience Vol.28 No.8

The objective of this study was to establish the optimum protocol for the isolation and culture of porcine muscle satellite cells. Mononuclear muscle satellite cells are a kind of adult stem cell, which is located between the basal lamina and sarcolemma of muscle fibers and is the primary source of myogenic precursor cells in postnatal muscle. Muscle satellite cells are a useful model to investigate the mechanisms of muscle growth and development. Although the isolation and culture protocols of muscle satellite cells in some species (e.g. mouse) have been established successfully, the culture system for porcine muscle satellite cells is very limited. In this study, we optimized the isolation procedure of porcine muscle satellite cells and elaborated the isolation and culture process in detail. Furthermore, we characterized the porcine muscle satellite cells using the immunofluorecence. Our study provides a reference for the isolation of porcine muscle satellite cells and will be useful for studying the molecular mechanisms in these cells.

A Study on Cutting and Tribology Performances of TiN and TiAlN Coated Tools

Hua-Ying Li,Hui-Bo He,Wen-Qiang Han,Jun Yang,Tao Gu,Yuan-ming Li,류성기 한국정밀공학회 2015 International Journal of Precision Engineering and Vol. No.

TiN and TiAlN coatings were deposited on the surface of AISI 5140 steel and cemented carbide YT15 by magnetron sputteringtechnique (MSP). The reciprocating sliding tests of TiN and TiAIN coatings on the surface of AISI 5140 steel were performed toinvestigate the friction coefficients of coatings affected by various normal loads with friction pair of 304 stainless steel balls. Drymachining tests on AISI 5140 hardened steel were carried out with the TiN and TiAlN coated tools on a CA6140A lathe. The effectsof cutting speed on cutting forces and surface roughness of TiN and TiAlN coated tools were obtained and analyzed to assess thecutting performance of coated tools. The microcosmic micrographs of wear areas of coated tools were observed and investigated byscanning electron microscope and energy dispersive spectrum. The results show that the friction coefficients of TiN coatings are lowerthan that of TiAlN coatings. The cutting force of TiAlN coated tool decreases and flank wear resistance enhances in comparison withTiN coated tool. The wear form and mechanisms of TiN coated tool are mainly crater wear on the rake face and adhesive wear andabrasive wear on the flank face. The wear form and mechanisms of TiAlN coated tool are mainly adhesive wear, the breakage ofcutting edge and the damage of tip, accompanied with diffusion and oxidation wear.

Dynamic stiffness matrix of an axially loaded slenderdouble-beam element

Jun, Li,Hongxing, Hua,Xiaobin, Li Techno-Press 2010 Structural Engineering and Mechanics, An Int'l Jou Vol.35 No.6

The dynamic stiffness matrix is formulated for an axially loaded slender double-beam element in which both beams are homogeneous, prismatic and of the same length by directly solving the governing differential equations of motion of the double-beam element. The Bernoulli-Euler beam theory is used to define the dynamic behaviors of the beams and the effects of the mass of springs and axial force are taken into account in the formulation. The dynamic stiffness method is used for calculation of the exact natural frequencies and mode shapes of the double-beam systems. Numerical results are given for a particular example of axially loaded double-beam system under a variety of boundary conditions, and the exact numerical solutions are shown for the natural frequencies and normal mode shapes. The effects of the axial force and boundary conditions are extensively discussed.

Mechanism of Fatty Acid Synthase in Drug Tolerance Related to Epithelial-mesenchymal Transition of Breast Cancer

Li, Jun-Qin,Xue, Hui,Zhou, Lan,Dong, Li-Hua,Wei, Da-Peng,Li, Hua Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.18

Objective: The mechanism of action of fatty acid synthase (FASN) in drug tolerance of breast cancer cells with epithelial-mesenchymal transition (EMT) features was investigated. Methods: The breast cancer cell line MCF-7-MEK5 with stably occurring EMT and tumour necrosis factor-${\alpha}$ (TNF-${\alpha}$) tolerance was used as the experimental model, whereas MCF-7 acted as the control. Tumour cells were implanted into nude mice for in vivo analysis, and cerulenin was used as a FASN inhibitor. RT-PCR, real-time quantitative PCR and Western blot were employed to detect the expression of FASN, TNFR-1, TNFR-2, Wnt-1, ${\beta}$-catenin and cytC at the RNA and protein levels. Results: Compared with MCF-7, TNFR-1 expression in MCF-7-MEK5 was slightly changed, TNFR-2 was decreased, and FASN, Wnt-1, ${\beta}$-catenin and cytC were increased. The expression of Wnt-1 and ${\beta}$-catenin in MCF-7-MEK5 decreased after cerulenin treatment, whereas cytC expression increased. Conclusions: The important function of FASN in the drug tolerance of breast cancer may be due to the following mechanisms: FASN downregulated TNFR-2 expression through lipid rafts to make the cells less sensitive to TNF-${\alpha}$, and simultaneously activated the Wnt-$1/{\beta}$-catenin signalling pathway. Thus, cytC expression increased, which provided cells with anti-apoptotic capacity and induced drug tolerance.