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.

Intrinsic origin of amyloid aggregation: Behavior of histidine (εεε) and (δδδ) tautomer homodimers of Aβ (1–40)

Salimi, Abbas,Li, Hao,Shi, Hu,Lee, Jin Yong Elsevier 2019 Biochimica et biophysica acta, General subjects Vol.1863 No.5

<P><B>Abstract</B></P> <P>Amyloid-beta protein (Aβ) accumulation in the brain, which is influenced by several factors, is a hallmark of Alzheimer's disease (AD). Despite the important role of histidine in stabilizing the fibrillar structure of the Aβ peptide at neutral pH, the effect of histidine tautomerism on Aβ peptide aggregation is still largely unknown. Histidine is in equilibrium between δ and ε tautomers and there are three histidine residues (H6, H13, and H14) in the Aβ(1–40) peptide. We performed molecular dynamics simulation on (δδδ) and (εεε) histidine tautomers with different initial homodimeric configurations to elucidate structural and aggregation features. Results indicate that (εεε) homodimers have very low propensity or almost no tendency to form β-sheets, whereas (δδδ) dimers predominantly form β-sheets due to interactions between central hydrophobic core (CHC) residues and C-terminal residues. β-sheet formation occurred in the same regions of each dimer chain at the CHC and C-/N- terminals for different configurations of (δδδ). These results suggest that (δδδ) has an important role in AD progression. Our study provides deeper insight into the effect of tautomerism of histidine residues in Aβ(1–40) on amyloid aggregation.</P> <P><B>Highlights</B></P> <P> <UL> <LI> (εεε) tautomers show low propensity to form β-sheets during homodimerization. </LI> <LI> (δδδ) tautomers show high β-sheets amount during homodimerization. </LI> <LI> (δδδ) tautomers may play more important role than (εεε) in Alzheimer. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Insect-specific microRNA involved in the development of the silkworm Bombyx mori

Yong Zhang,Xue Zhou,Xie Ge,Jiang-Hao Jiang,Mu-Wang Li,Shi-Hai Jia,Xiao-Nan Yang,Yun-Chao Kan,Xue-Xia Miao,Guo-Ping Zhao,Fei Li,Yong-Ping Huang 한국응용곤충학회 2009 한국응용곤충학회 학술대회논문집 Vol.2009 No.10

MicroRNAs (miRNAs) are endogenous non-coding genes that participate in post-transcription regulation by either degrading mRNA or blocking its translation. It is considered to be very important in regulating insect development and metamorphosis. Insects are the largest group of animals and are extremely valuable in biological and agriculture research. Insects are also important pests to human health and agriculture, and efforts are necessary protect both humans and plants from disease and damage. Despite their importance, insects lag behind mammals, nematodes, and plants in miRNA research. At present, only 279 insect miRNAs have been identified from Drosophila melanogaster, Anopheles gambiae, Apis mellifera, Bombyx mori, and D. pseudoobscura in miRBase, and most of these miRNAs were computationally predicted without experimental validation. Functional analysis of insect miRNAs has only been conducted in D. melanogaster.

An Antiviral Mechanism Investigated with Ribavirin as anRNA Virus Mutagen for Foot-and-mouth Disease Virus

Li-li Shi,Cong-yi Zheng,Chao-jiang Gu,Qian Zhang,Yong Li,San-fu Qu 한국생화학분자생물학회 2006 BMB Reports Vol.39 No.1

Theoretical and Exprerimental Sutdy on Interactive Local Buckling of Arch-shaped Corrugated Steel Roof

Li-Li Wu,Xuan-Neng Gao,Yong-Jiu Shi,Yuan-Qing Wang 한국강구조학회 2006 International Journal of Steel Structures Vol.6 No.3

The arch-shaped corugated steel roof is a new type of cold formed thin-waled structure. Since the width-to-thickness ratiosof the plate asemblies of corrugated sections exceed the limits specified in the current design codes, the load-bearingbehavior, especialy loading modes, initial imperfections and boundary conditions, therefore its ultimate load-carying capacityis determined not only by its global stability, but also by its interactive local buckling. In this paper the finite element methodwas aplied to analyze the local buckling behavior of stel arch panels with corrugated trapezium sections. Some tests on theloads to further investigate the loading mechanism of corrugated steel arch panels and the factors refered above. A comparisonbetween the experimental and theoretical results was made, and good agrement was achieved herein. It is shown that therealso exists interactive local buckling among corugated plate assemblies. The experimental results are lower than theoreticalones for axial loading capacity, vice-versa, the former ones are higher for eccentricaly loaded specimens. It is noted that thealso indicate that the trapezium sections have high local buckling capacities, yet they hardly have post-buckling capacities,which are distinctive from that of the plain ones. All these also give some explanations to some corugated steel arch rofscolapsed suddenly in some areas of China.

Research on the Fluctuation of Pork Prices in China under Major Sudden Public Safety Events

Shi-Yong Piao(박세영),Yuan-Ze Shi(사원택),Li-Ling Jin(김려령),Jong-In Lee(이종인) 한국산학기술학회 2024 한국산학기술학회논문지 Vol.25 No.5

2020년 초부터 2022년 말까지의 주요 급발적 공중보건 사건(COVID-19 등)이 중국의 농산물 시장, 특히 돼지고기 가격에 큰 변동성을 가져왔다. 돼지고기 가격의 파동은 국가의 규제와 국민의 식생활에 큰 영향을 주었다. 본 연구는 2020~2022년 중국 돼지고기 가격, 코로나 확진자 등의 데이터를 바탕으로 VECM 오차 보정 모델을 사용하여 주요급발적 공중보건 사건시기 돼지고기 가격에 영향을 주는 요인을 분석하였다. 결과적으로, 주요 급발적 공중보건 사건 초기에는 COVID-19 확진자와 돼지고기 가격이 강한 정의 상관관계를 보였으나, 시간이 흐름에 따라 약화되었다. 연구결과 바탕으로, 돼지고기 가격의 안정화를 위한 조치와 이에 대한 제안을 제시하였다. From early 2020 to the end of 2022, major sudden public health events, such as COVID-19, significantly influenced the agricultural market in China, with pork prices experiencing substantial volatility. This turbulence in pork prices had profound implications for national regulations and the dietary habits of the populace. Based on data concerning pork prices and COVID-19 infection rates in China from 2020 to 2022, this study employed the VECM error correction model to analyze factors impacting pork prices during these major public health events. Results revealed that in the initial stages of the significant public health events, there was a strong positive correlation between COVID-19 confirmed cases and pork prices, which weakened over time. Drawing on these findings, measures and recommendations were put forth to stabilize pork prices.

Malmquist모형을 이용한 중국 랴오닝성 농업생산효율성 분석

박세영(Shi-Yong Piao),김려령(Li-Ling Jin),사원택(Yuan-Ze Shi),이종인(Jong-In Lee) 한국산학기술학회 2024 한국산학기술학회논문지 Vol.25 No.5

중국 일부 지역의 농업생산은 여전히 소농경제의 영향을 받고 있으며 소농경제의 본질에서 벗어나지 못했기 때문에 농업 생산효율이 낮은 편이다. 농업생산 효율의 향상은 농업 발전에 아주 중요한 역할을 한다. 농업생산 효율의 수준은 지역 농업의 발전 수준을 직접 반영하므로 농업생산 효율의 향상은 지속 가능한 농업 발전을 실현하는 관건이다. 랴오닝성은 중국의 주요 식량 생산기지이며, 농업 발전에서 큰 잠재력을 가지고 있다. 본 연구에서는 중국 랴오닝성의 농업생산 효율성에 대하여 분석하였다. 이를 위하여 2011년부터 2020년까지의 중국통계연감의 데이터를 이용하여, Malmquist 모형을 통해 랴오닝성 14개 도시의 농업 생산성 변화를 분석하여 농업생산 효율성을 평가하였다. 연구 결과 10년 간 MPI는 전반적으로 비교적 낮은 수준에 머물러 있으며, 평균 기술 효율성 지수와 평균기술변화지수가 역 발전추세가 있고 규모 효율과 기술효율이 비교적 낮다. 그리고 농업 생산효율의 연간 증가의 주요 원인은 기술발전임을 확인하였다. 랴오닝성은 농업 기술 투입을 증대하고 정부의 지원을 강화하며 농업생산에 대한 적극성을 높여야 한다. 연구결과를 바탕으로, 랴오닝성 농업생산 효율성의 향상을 위한 조치와 이에 대한 제안을 제시하였다. Agricultural production in some parts of China is still affected by the small farmer economy, and agricultural production efficiency is low because it remains rooted in the essence of the small farmer economy. Improved agricultural production efficiency plays a central role in agricultural development. Agricultural production efficiency levels directly reflect the level of development of local agriculture, and thus, improvements in agricultural production efficiency are key to realizing sustainable agricultural development. Liaoning is a major food production base in China and has great potential for agricultural development. In this study, we analyze the efficiency of agricultural production in Liaoning Province. To this end, agricultural productivity changes in 14 cities in Liaoning Province were evaluated using the Malmquist model and data from the Chinese Statistical Yearbook from 2011 to 2020. The results showed that overall MPI has remained at a relatively low level for 10 years. Average technology efficiency and change indices revealed a reverse development trend and relatively low scale and technology efficiencies. In addition, the study confirms that technological development was the leading cause of an annual increase in agricultural production efficiency. Liaoning should increase the input of agricultural technology, strengthen government support, and increase its active involvement in agricultural production. Measures and suggestions for improving agricultural production efficiency in Liaoning Province were presented based on the results obtained.

Cavitation cloud dynamic characteristics of dual-chamber self-excited oscillatory waterjet

Dezheng Li,Yong Kang,Hanqing Shi,Yi Hu,Qi Liu,Hongchao Li,Jincheng Hu,Jiamin Li 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.12

Aiming to enhance self-excited oscillating cavitation jet performance, the effect of the dual-chamber nozzlestructure on the jet dynamical characteristics was designed and investigated. With high-speed camera technology,the cavitation phenomenon was investigated to analyze the area pattern and shedding period of the cavitation cloudunder different nozzle structures. The results showed that the dual-chamber nozzle significantly improved the jet cavitationstrength, and the cavitation cloud area increased by 76% and decreased the shedding period by 90% comparedwith the single-chamber nozzle. In the upstream chamber, the upper shrinkage ratio had a more drastic effect on thecavitation cloud area and shedding frequency than the lower shrinkage ratio with a more sensitive effect on the sheddingfrequency. In the downstream chamber, the outlet diameter ratio and chamber diameter were more sensitive tothe regulation of cavitation cloud shedding frequency and area, respectively, with the optimal regulation at the outletdiameter ratio of 1 and chamber length of 6 mm. The chamber diameter modulated the cavitation cloud most drasticallywith a comprehensive performance optimum at 12mm, which the area fluctuation reached 76.8%. The resultsprovide a basis for further research and application of dual-chamber nozzles.

Risk assessment of water inrush in karst tunnels based on a modified grey evaluation model: Sample as Shangjiawan Tunnel

Yuan, Yong-cai,Li, Shu-cai,Zhang, Qian-qing,Li, Li-ping,Shi, Shao-shuai,Zhou, Zong-qing Techno-Press 2016 Geomechanics & engineering Vol.11 No.4

A modified grey clustering method is presented to systematically evaluate the risk of water inrush in karst tunnels. Based on the center triangle whitenization weight function and upper and lower limit measure whitenization weight function, the modified grey evaluation model doesn't have the crossing properties of grey cluster and meets the standard well. By adsorbing and integrating the previous research results, seven influence factors are selected as evaluation indexes. A couple of evaluation indexes are modified and quantitatively graded according to four risk grades through expert evaluation method. The weights of evaluation indexes are rationally distributed by the comprehensive assignment method. It is integrated by the subjective factors and the objective factors. Subjective weight is given based on analytical hierarchy process, and objective weight obtained from simple dependent function. The modified grey evaluation model is validated by Jigongling Tunnel. Finally, the water inrush risk of Shangjiawan Tunnel is evaluated by using the established model, and the evaluation result obtained from the proposed method is agrees well with practical situation. This risk assessment methodology provides a powerful tool with which planners and engineers can systematically assess the risk of water inrush in karst tunnels.

Diversity of Endophytic Fungi from Different Verticillium-Wilt-Resistant Gossypium hirsutum and Evaluation of Antifungal Activity Against Verticillium dahliae In Vitro

( Zhi Fang Li ),( Ling Fei Wang ),( Zi Li Feng ),( Li Hong Zhao ),( Yong Qiang Shi ),( He Qin Zhu ) 한국미생물 · 생명공학회 2014 Journal of microbiology and biotechnology Vol.24 No.9

Cotton plants were sampled and ranked according to their resistance to Verticillium wilt. In total, 642 endophytic fungi isolates representing 27 genera were recovered from Gossypium hirsutum root, stem, and leaf tissues, but were not uniformly distributed. More endophytic fungi appeared in the leaf (391) compared with the root (140) and stem (111) sections. However, no significant difference in the abundance of isolated endophytes was found among resistant cotton varieties. Alternaria exhibited the highest colonization frequency (7.9%), followed by Acremonium (6.6%) and Penicillium (4.8%). Unlike tolerant varieties, resistant and susceptible ones had similar endophytic fungal population compositions. In three Verticillium-wilt-resistant cotton varieties, fungal endophytes from the genus Alternaria were most frequently isolated, followed by Gibberella and Penicillium. The maximum concentration of dominant endophytic fungi was observed in leaf tissues (0.1797). The evenness of stem tissue endophytic communities (0.702) was comparatively more uniform than the other two tissues. Eighty endophytic fungi selected from 27 genera were evaluated for their inhibition activity against highly virulent Verticillium dahliae isolate Vd080 in vitro. Thirty-nine isolates exhibited fungistasis against the pathogen at varying degrees. Seven species, having high growth inhibition rates (≥75%), exhibited strong antifungal activity against V. dahliae. The antifungal activity of both volatile and nonvolatile metabolites was also investigated. The nonvolatile substances produced by CEF-818 (Penicillium simplicissimum), CEF-325 (Fusarium solani), CEF-714 (Leptosphaeria sp.), and CEF-642 (Talaromyces flavus) completely inhibited V. dahliae growth. These findings deepen our understanding of cotton-endophyte interactions and provide a platform for screening G. hirsutum endophytes with biocontrol potential.