波形 有孔岸壁의 性能評價 - 水理模型實驗

이두성,홍군희,전인식 건국대학교 산업기술연구원 2001 건국기술연구논문지 Vol.26 No.-

Since ports, harbors, and coastal structures are affected by waves in any way, waves have a great effect on determining the stability of coastal structures. Especially, regardless of ship's size, the efficiency of shipping and discharging depends on harbor tranquility. Therefore in this study, the wave action is a considered to be a major factor to design coastal structure. So experiments were performed with various models of quay wall by examining their hydraulic characteristics for reflection rates and wave run-up. The final purpose of this study is to design various domestic unique models of quay wall which have the function of wave dissipation to improve cargo handling efficiency. The reflection rates and ship motions of three degrees of freedom-3DOF(sway, heave, roll) are also calculated by boundary element method (BEM). Calculated reflection rates from the BEM are compared with the results from the hydraulic model experiment. Although the values of numerical analysis generally exceed the values of hydraulic experiment, they showed the similar trend.

Tunable magnetic properties of double perovskite La₂Fe_2-xCo_xO₆

Wang, Weihua,Feng, Wuwei,Yuan, Jiangyan,Pang, Ning,Zhao, Xiaoxue,Li, Meiyun,Bao, Zhidi,Zhu, Kun,Odkhuu, Dorj Elsevier 2018 PHYSICA B-CONDENSED MATTER - Vol.540 No.-

<P><B>Abstract</B></P> <P>Double perovskite La<SUB>2</SUB>Fe<SUB>2-x</SUB>Co<SUB>x</SUB>O<SUB>6</SUB> was prepared and studied. Orthorhombic and trigonal structures were obtained depend on the molar ratio of Fe to Co. Fe-rich sample demonstrate ferrimagnetic properties; with increasing content of Co, trigonal structure is favored and the net magnetic moment of sample decrease gradually to zero. Our experimental results were further supported by first-principle theoretical calculations and demonstrate that La<SUB>2</SUB>Fe<SUB>2-x</SUB>Co<SUB>x</SUB>O<SUB>6</SUB> is a new high <I>T</I> <SUB> <I>c</I> </SUB> ferromagnetic semiconductor with tunable magnetic properties and is thus a promising material for spintronics devices.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Phase-pure double perovskite La2Fe2-xCoxO6 was prepared. </LI> <LI> Orthorhombic and trigonal structures were obtained depending on the ratio of Fe to Co. </LI> <LI> La2Fe2-xCoxO6 is a new high Tc ferromagnetic semiconductor with tunable magnetic properties. </LI> <LI> Theoretical ab initio calculations further support our experimental results. </LI> </UL> </P>

Multi-functional transparent electrode for reliable flexible perovskite solar cells

Han, Gill Sang,Lee, Seongha,Duff, Matthew Lawrence,Qin, Fen,Jiang, Minlin,Li, Guangyong,Lee, Jung-Kun Elsevier 2019 Journal of Power Sources Vol.435 No.-

<P><B>Abstract</B></P> <P>Multilayer MoO<SUB>x</SUB>/Ag/MoO<SUB>x</SUB> (DMD) films are found to be transparent conducting electrodes for use in extremely stable and highly bendable flexible perovskite solar cells (PSCs). The optical transparency and electric properties of DMD and its role as a top electrode of PSCs were studied by changing the thickness of the MoO<SUB>x</SUB> layer. Although the MoO<SUB>x</SUB> thickness was shown to have a negligible effect on the sheet resistance of DMD, the transmittance of visible light, selective carrier transport capability, and long-term stability of a device considerably depend on this factor. The sandwich structure of a 20-nm-thick MoO<SUB>x</SUB>, 7-nm-thick Ag, and 20-nm-thick MoO<SUB>x</SUB> exhibits a high transmittance and large photon–electron conversion rate of PSCs. In addition, PSCs using the DMD top electrode maintain 92% of their initial current density after 24 h of continuous operation owing to a UV light cut-off of the top illumination. Moreover, the overall structure of DMD blocks the diffusion of water and oxygen molecules from real environmental conditions. At the same time, the underlying/upper MoO<SUB>x</SUB> layer retards the degradation through a chemical reaction between Ag and the halide ions inside the cells, as well as foreign ions from outside the polluted atmosphere. When DMD is applied to flexible PSCs on Ti foil, the PCE reaches 14.5%, and mechanical integrity of the PSCs is maintained at a bending radius of 4 mm.</P> <P><B>Highlights</B></P> <P> <UL> <LI> MoO<SUB>x</SUB>/Ag/MoO<SUB>x</SUB> multilayer is used as a top electrode of perovskite solar cells. </LI> <LI> The multilayer electrode has multiple functions in real operation environment. </LI> <LI> 92% of the initial current density is maintained after 24 h continuous operation. </LI> <LI> The efficiency of flexible solar cells using MoO<SUB>x</SUB>/Ag/MoO<SUB>x</SUB> reaches 14.5%. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Anti-allergic Effects and Related Active Constituents of Mung Bean (Vignaradiatus Linn) Sprouts

Li Li,Min-hui Li,Han-kun Ren,Yujing Shi,Yin-mao Dong 한국식품과학회 2016 Food Science and Biotechnology Vol.25 No.2

The mung bean (Vigna radiata) is an important food crop with preventative effects against human diseases. The anti-allergic activities of mung bean sprouts of different lengths were evaluated by assaying in vivo antipruritic activity and in vitro hyaluronidase inhibitory effects. After 48 h of growth, sprouts were determined to have the best activity and extracted with petroleum (PeF), ethyl acetate (EaF), and n-butanol (nBF). The active EaF extracts were further assayed for in vivo effects on compound 48/80-induced mast cell degranulation and histamine release, as well as the antidinitrophenyl (DNP) IgE-induced passive cutaneous anaphylaxis (PCA) reaction. The main chemical constituents were further analyzed by UV spectrophotometry and high-performance liquid chromatography with tandem mass spectrometric detection (LC/MS/MS). EaF significantly protected against compound 48/80-induced mast cell degranulation and histamine release, and PCA. Flavonoids were determined to be the main contributors to the anti-allergic activity of the EaF extracts.

Five novel species of the genus Nocardiopsis isolated from hypersaline soils and emended description of Nocardiopsis salina Li et al. 2004

Li, Wen-Jun,Kroppenstedt, Reiner M.,Wang, Dong,Tang, Shu-Kun,Lee, Jae-Chan,Park, Dong-Jin,Kim, Chang-Jin,Xu, Li-Hua,Jiang, Cheng-Lin Microbiology Society 2006 International journal of systematic and evolutiona Vol.56 No.5

<P>Five novel Nocardiopsis strains isolated from hypersaline soils in China were subjected to a polyphasic analysis to determine their taxonomic position. All of the novel isolates could grow on agar plates at NaCl concentrations of up to 18 % (w/v), with optimum growth at 5-8 %. The DNA G+C contents of the novel strains ranged from 67.9 to 73.2 mol%. The morphological and chemotaxonomic characteristics of the isolates matched those described for members of the genus Nocardiopsis. Based on their 16S rRNA gene sequence analysis, DNA-DNA hybridization values and phenotypic characteristics, including the composition of cell-wall amino acids and sugars, menaquinones, polar lipids and cellular fatty acids, the isolates are proposed as representing five novel species of the genus Nocardiopsis. The novel species are proposed as Nocardiopsis gilva sp. nov. [type strain YIM 90087T (=KCTC 19006T=CCTCC AA 2040012T=DSM 44841T)], Nocardiopsis rosea sp. nov. [type strain YIM 90094T (=KCTC 19007T=CCTCC AA 2040013T=DSM 44842T), Nocardiopsis rhodophaea sp. nov. [type strain YIM 90096T (=KCTC 19049T=CCTCC AA 2040014T=DSM 44843T), Nocardiopsis chromatogenes sp. nov. [type strain YIM 90109T (=KCTC 19008T=CCTCC AA 2040015T=DSM 44844T) and Nocardiopsis baichengensis sp. nov. [type strain YIM 90130T (=KCTC 19009T=CCTCC AA 2040016T=DSM 44845T). On the basis of the chemotaxonomic data, the description of the recently described species Nocardiopsis salina Li et al. 2004 is emended.</P>

Research on Configuration Process of Nuclear Power Valve Design System based on Axiomatic Design

Li Yuan,Dai Ye,Li Kun 보안공학연구지원센터 2014 International Journal of Control and Automation Vol.7 No.10

In order to construct the design system of nuclear power valve, the axiomatic design theory is introduced in configuration process of the valve structure design. According to the functional requirement and the complex mechanical structure of the nuclear power valves, the relationship model between design parameters and functional requirements is created by using the“zigzagging”mapping. Then the design matrix can be established and the design order can be planned. After that, the complete mapping table in design process is established through decoupling to quasi-coupling design, and the valve design process according to axiomatic method is constructed. On this basis, a rapid design system is constructed by combining the structural features with the multi-characteristic optimization requirement, in which the configuration process model established by axiomatic method provides valve design in integrated system with reasonable navigation and improves the rationality and the objectivity in design development process.

Overexpression of Cyclin L2 Inhibits Growth and Enhances Chemosensitivity in Human Gastric Cancer Cells

Li, Hong-Li,Huang, Ding-Zhi,Deng, Ting,Zhou, Li-Kun,Wang, Xia,Bai, Ming,Ba, Yi Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.4

Cyclin L2 is a novel member of the cyclin family, recently implicated in the regulation of cell cycle progression and/or transcriptional regulation. The present study was undertaken to investigate the effects of overexpression on tumor cell growth and chemosensitivity in human gastric cells in vitro. Cyclin L2 was transfected into human gastric cancer cell line BCG823 and expressed with a mammalian expression vector pcDNA3.1. The effects and mechanisms of cyclin L2 on cell growth, cell cycling and apoptosis were studied. Compared to control vectors, overexpression of cyclin L2 inhibited the growth of BCG823 cells and enhance their chemosensitivity to fluorouracil, docetaxel and cisplatin. The anti-proliferative effects of cyclin L2 could be due to G0/G1 arrest and apoptosis. Cyclin L2 induced G0/G1 arrest and apoptosis involved upregulation of caspase-3 and down regulation Bcl-2 and survivin. The results indicated that overexpression of cyclin L2 protein may promote efficient growth inhibition and enhance chemosensitivity to chemotherapeutic agents in human gastric cancer cells by inducing G0/G1 cell cycle arrest and apoptosis.

Separation of valuable metals from mixed cathode materials of spent lithium-ion batteries by single-stage extraction

Yongjie Li,Qiang Fu,Hongyun Qin,Kun Yang,Junnan Lv,Qicheng Zhang,Zhang Hui,Feng Liu,Xia Chen,Ming Wang 한국화학공학회 2021 Korean Journal of Chemical Engineering Vol.38 No.10

With the intensity of resource scarcities and environmental problems, the disposal and recovery of spent lithium-ion batteries, especially recovery of valuable metals, becomes vital. In this work, a method of co-extracting nickel, cobalt, manganese and being separated from lithium by single-stage solvent extraction is proposed. The extraction and separation process of D2EHPA was studied. The effects of extractant concentration, saponification percentage, extraction time and O:A on the extraction efficiency of D2EHPA were systematically studied. Nearly 100% manganese, 94% cobalt and about 90% nickel were co-extracted and separated from lithium using D2EHPA in kerosene by single-stage extraction. The maximum value of separation factors (Ni/Li, Co/Li and Mn/Li) was 13.03, 23.42 and 1904.24. The mathematical model of extraction of four ions was developed by combination of Levenberg-Marquardt method and Universal Global Optimization method. The proposed extraction model accurately fits the experimental data and helps to predict the extraction efficiency of each metal under the corresponding conditions.

Improving the Capture-range Problem in Phase-diversity Phase Retrieval for Laser-wavefront Measurement Using Geometrical-optics Initial Estimates

Li Jie Li,Wen Bo Jing,Wen Shen,Yue Weng,Bing Kun Huang,Xuan Feng 한국광학회 2022 Current Optics and Photonics Vol.6 No.5

To overcome the capture-range problem in phase-diversity phase retrieval (PDPR), a geometricaloptics initial-estimate method is proposed to avoid a local minimum and to improve the accuracy of laser-wavefront measurement. We calculate the low-order aberrations through the geometrical-optics model, which is based on the two spot images in the propagation path of the laser, and provide it as a starting guess for the PDPR algorithm. Simulations show that this improves the accuracy of wavefront recovery by 62.17% compared to other initial values, and the iteration time with our method is reduced by 28.96%. That is, this approach can solve the capture-range problem.

Seismic analysis of bridges based on stress-dependent damping

Li Su,Yuanfeng Wang,Pengfei Li,Shengqi Mei,Kun Guo 국제구조공학회 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.62 No.3

Damping value has considerable influence on the dynamic and seismic behaviors of bridges. However, currently the constant damping ratios that are prescribed by most bridge seismic design codes can’t truly represent the complicated damping character of actual structures. In this paper, a cyclic loading experiment was conducted to study the effect of stress amplitude on material damping of concrete to present an analyzing model of the material damping of concrete. Furthermore, based on the fundamental damping of structure measured under ambient vibration, combined with the presented stress-dependent material damping concrete, the seismic response of a bridge pier was calculated. Comparison between the calculated and experiment results verified the validity of the presented damping model. Finally, a modified design and analysis method for bridge was proposed based on stress-dependent damping theory, and a continuous rigid frame bridge was selected as the example to calculate the actual damping values and the dynamic response of the bridge under different earthquake intensities. The calculation results indicated that using the constant damping given by the Chinese seismic design code of bridges would overestimate the energy dissipation capacity of the bridge.