Effect of Li Content on the Surface Film Formed on the Binary Mg–Li Alloys in NaCl Solution

Chuanqiang Li,Dahui Liang,Yejia Lin,Yong Dong,Binqing Shi,Changjian Yan,Zhengrong Zhang 대한금속·재료학회 2024 METALS AND MATERIALS International Vol.30 No.1

The surface film formed on the Mg–Li alloys with different Li content in 0.1 M NaCl solution were investigated via electrochemicaltesting, morphologies observation and chemical composition analysis in this work. The results revealed that thesurface film of Mg–14Li alloy (L14: body centred cubic (BCC)) possessed higher electrical resistivity and remained a highertolerating over-potential (0.1 V vs. open circuit potential) than those of Mg–4Li (L4: hexagonal closed-packed (HCP)) andMg–7.5Li (L7: HCP+BCC), resulting in a better corrosion performance. After 24 h immersion in NaCl solution, the wholesurface film of L14 remained undamaged and displayed weave-like and dense characteristic, while both L4 and L7 present aseverely damaged film. The cross-sectional details illustrated typical two layers of surface film formed on L14 with the outerlayer of ~ 1.5 μm and inner layer of ~ 2.5 μm in thickness, whilst only one layer of film with less than 2.5 μm in thicknesswas observed on L4 and L7. At last, combining analysis of X-ray diffraction, energy dispersive X-ray spectrometry, X-rayphotoelectron spectroscopy and transmission electron microscope confirmed the composition of outer layer of surface filmon the L14 contains much more Mg(OH)2 and Li-containing compounds, and the porous Mg(OH)2 film can be sealed by theLi-containing compounds, which is very different the single Mg(OH)2 film on the traditional magnesium and L4/L7 alloys. As a result, the best protective function of the surface film on the L14 alloy contribute to its high corrosion resistance.

White-Matter Hyperintensities and Lacunar Infarcts Are Associated with an Increased Risk of Alzheimer’s Disease in the Elderly in China

Shuai Ye,Shuyang Dong,Jun Tan,Le Chen,Hai Yang,Yang Chen,Zeyan Peng,Yingchao Huo,Juan Liu,Mingshan Tang,Yafei Li,Huadong Zhou,Yong Tao 대한신경과학회 2019 Journal of Clinical Neurology Vol.15 No.1

Background and Purpose This study investigated the contribution of white-matter hyperintensities (WMH) and lacunar infarcts (LI) to the risk of Alzheimer’s disease (AD) in an elderly cohort in China. Methods Older adults who were initially cognitively normal were examined with MRI at baseline, and followed for 5 years. WMH were classified as mild, moderate, or severe, and LI were classified into a few LI (1 to 3) or many LI (≥4). Cognitive function was assessed using the Mini Mental State Examination and the Activities of Daily Living scale. Results Among the 2,626 subjects, 357 developed AD by the end of the 5-year follow-up period. After adjusting for age and other potential confounders, having only WMH, having only LI, and having both WMH and LI were associated with an increased risk of developing AD compared with having neither WMH nor LI. Moderate and severe WMH were associated with an increased risk of developing AD compared with no WMH. Furthermore, patients with many LI had an increased risk of developing AD compared with no LI. Conclusions Having moderate or severe WMH and many LI were associated with an increased risk of developing AD, with this being particularly striking when both WMH and LI were present.

Microstructure Evolution and Mechanical Properties of AA2099 Al–Li Alloy with Tailored Li‐Containing Precipitates in Uniaxial Compression at Medium Temperature

Li Hu,Mengdi Li,Weijiu Huang,Xusheng Yang,Fei Guo,Haipeng Dong 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.5

Microstructure characteristics and mechanical behavior of AA2099 Al–Li alloy with no pre-existing Li-containing precipitates(AA2099-1 sample), pre-existing δ′ precipitates (AA2099-2 sample), pre-existing T1phase (AA2099-3 sample) andpre-existing T2phase (AA2099-4 sample) are systematically investigated via isothermal uniaxial compression at 250 °C inthe present study. Experimental results demonstrate that at the onset of plastic deformation, dynamic precipitation of smallsizedT1phase occurs rapidly within AA2099-1 sample, while it will be hindered within AA2099-2 sample. The increasingplastic strain benefits to dynamic precipitation of small-sized T1phase in AA2099-2 sample. Consequently, AA2099-1 andAA2099-2 samples possess similar and intermediate mechanical behaviors. In terms of AA2099-3 sample, the existence oflarge-sized T1phase results in the maximum yielding stress. However, some regions within these large-sized T1precipitatesare suspected to be sheared by cross-slip, leading to the destruction of crystallographic structure and the formation of Almatrix intervals. This aspect is responsible for the gradual degradation in true stress-strain curve after peak stress. As forAA2099-4 sample, dynamic precipitation rarely happens during plastic deformation and the interaction between dislocationand the pre-existing T2phase belongs to Orowan looping, resulting in the minimal mechanical response. Besides,AA2099-1 sample possesses the average minimum deviation angle (MDA) of ~ 16.5° between the loading direction and the<110> crystal direction, whereas AA2099-4 sample owns the average MDA of ~ 7.5°. The difference in MDA is mainlyattributed to δ′ phase and T1phase, which will separately accelerate and postpone the rotation of orientation towards the<110> crystal direction.

Mechanism and process for the extraction of lithium from the high magnesium brine with N,N-bis(2-ethylhexyl)-2-methoxyacetamide in kerosene and FeCl3

Lianmin Ji,Licheng Zhang,Dong Shi,Xiaowu Peng,Jinfeng Li,Yuze zhang,Taoshan Xu,Lijuan Liao 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.113 No.-

The degradation of TBP has become a stumbling block to the industrial continuous production of lithiumchloride extraction from brines with high Mg/Li ratio by solvent extraction. To develop a more stable andmore efficient extraction system, a novel amide system, containing newly synthesized extractant N,N-bis(2-ethylhexyl)-2-methoxyacetamide (NBEHMOA), FeCl3 6H2O and sulfonated kerosene, was proposed inthis work. Compared with TBP and N523, NBEHMOA extracted Li+ and H+ in the sequence of TBP ˃NBEHMOA ˃ N523 and N523 ˃ TBP ˃ NBEHMOA respectively. The solution containing 5.5 mol/L LiCland 0.5 mol/L HCl was used as the eluent in the scrubbing process. A Li+ extraction efficiency of 96.7%and 22.31 g/L Li+ in the stripping solution were achieved by the whole process with counter-currenttwelve stages. The extraction mechanism investigated via FT-IR spectroscopy illustrated that the metalions Fe3+ and Li+ were mainly coordinated by the carbonyl C = O in NBEHMOA. This novel amide systemcan successfully achieve the cascade extraction effect for lithium, Li/Mg separation and avoid the generationof phase interface objects through counter-current extraction of lithium from brine at a lower acidity. This work provided a novel extraction system to recover lithium from the higher magnesium/lithiumratio brines.

Characteristics of isolated lactic acid bacteria and their effects on the silage quality

Siran Wang,Xianjun Yuan,Zhihao Dong,Junfeng Li,Gang Guo,Yunfeng Bai,Junyu Zhang,Tao Shao 아세아·태평양축산학회 2017 Animal Bioscience Vol.30 No.6

Objective: Four lactic acid bacteria (LAB) strains isolated from common vetch, tall fescue and perennial ryegrass on the Tibetan Plateau were characterized, and their effects on the fermentation quality of Italian ryegrass (Lolium multiflorum Lam.) silage were studied. Methods: The four isolated strains and one commercial inoculant (G, Lactobacillus plantarum MTD-1) were evaluated using the acid production ability test, morphological observation, Gram staining, physiological, biochemical and acid tolerance tests. The five LAB strains were added to Italian ryegrass for ensiling at three different temperatures (10°C, 15°C, and 25°C). Results: All isolated strains (LCG3, LTG7, I5, and LI3) could grow at 5°C to 20°C, pH 3.0 to 8.0 and NaCl (3.0%, 6.5%). Strains LCG3, LTG7, I5, and LI3 were identified as Lactobacillus plantarum, Pediococcus acidilactici, Lactobacillus paraplantarum, and Lactobacillus casei by sequencing 16S rDNA, respectively. All LAB inoculants significantly (p<0.05) increased lactic acid (LA) contents and ratios of lactic acid to acetic acid, and reduced pH and ammonia nitrogen/ total nitrogen (AN/TN) compared with uninoculated silages at various temperatures (10°C, 15°C, and 25°C). Compared to the commercial inoculant G, I5, and LI3 showed similar effects on improving the silage quality of Italian ryegrass at 10°C and 15°C, indicated by similar pH, LA content and AN/TN. Conclusion: All inoculants could improve the silage fermentation quality at various temperatures (10°C, 15°C, and 25°C). At the temperature of 10°C and 15°C, strain I5 and LI3 had similar effects with the commercial inoculant G on improving the silage quality of Italian ryegrass.

Morco Polo 以前의 印度洋世界에 관한 文獻

李東潤 단국대학교 대학원 1978 學術論叢 Vol.2 No.-

몽고제국 시대의 인도양세계에 관한 저작은 무엇보다도 Marco Polo와 Ibn Batutah의 여행기가 가장 중요하다. Marco Polo의 여행기에 관한 역주서가 많이 간행되었으나, Louis Hambis가 현대불어를 역주한 Marco Polo와 그의 은사 Paul Pelliot가 영어로 역주한 「Notes on Marco Polo」가 가장 믿을 만하다. 최근에 Jaceques Gernet가 「몽고침입전야의 중국인의 일상생활 : La vie quotidienne en Chine a` la veille de l'invasion mongole」이라는 저서를 발간하였는데, 그는 남송사회경제사라고 말할 수 있는 이 저술 안에서 Marco Polo의 여행기를 재치 있게 분석하였다. Gernet교수의 학풍과 연구업적에 대해서는 단국대학교 사학회간 사학지 제11운(p.251)과, 졸저 “불란서문화론” 제13장 프랑스에 있어서의 중국학의 발달 안에서 언급한 바 있다.

중국 인터넷 광고의 현황과 전망

이동진 광운대학교 인문사회과학연구소 2001 인문사회과학논문집 Vol.30 No.-

The internet advertising was begun in March, 1997 in China. The first one was Intels banner advertising on Chinabyte.com. On the base of the great scale of population and high growth of China economic, more and more internet advertising has been used. Now it is the important mass media which different from four big media. In this study the author proposed the future direction of internet advertising development in China under analysis of present conditions and problem with. First, internet advertising in China will maintain great development with the growth of internet user. High growth of Chinese economic will support its capability also. Second, foreign advertiser will also play leading role in internet advertising market in China, as they are the main advertisers and they hold the knowhow. With the China join WTO, more and more foreign advertising company who have great funds and skill will enter internet advertising market in China. If they want make success they must to understand the Chinese netizens property, because the mouse are in the Chinese netizens hands who expose to the advertisement.

자궁근종의 양성 폐전이 치료 1례

유애리,문성택,김윤숙,전섭,최승도,선우재근,배동한 순천향의학연구소 2008 Journal of Soonchunhyang Medical Science Vol.14 No.2S

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李無影의 初期作品에 나타난 文學思想 硏究 : 無依支와 廢墟에의 鬪魂 de´fi contre sans-appui et ruines

李東熙 단국대학교 1981 論文集 Vol.15 No.-

論朝鮮時代李后白詩歌的唐鳳宋韻

李娜,金東河 서강정보대학 2002 論文集 Vol.21 No.-

Chongnyon Lee Hu-baek was an honest officer who served the Ministry of King Sonjo of the Chosun Dynasty. At the same time, he was one of the famous writers during the reign of King Myongjong. Especially, he was an eminent poet in those days. As is generally known, Lee Hu-baek was a central figure in the transitional period, from the Song poetic style to the Tang poetic style, marking a turning point in the history of Korean literature. Kim Chang-hyop, the remarkable critic of the latter half of Chosun Dynasty, esteemed him as the pioneer of the Tang poetic style. But, as he lived in the transitional period, the two characteristics of Tang poetic style and Song poetic style at once in his poems, reflecting the phases of the times. So, in this thesis, we want to explore the mixed aspects through his representative works.