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Exfoliation corrosion of extruded Mg-Li-Ca alloy

Journal of Materials Science & Technology 2018年第9期34卷 1550-1557页

作者： Zi-You Ding Lan-Yue Cui Rong-Chang Zeng yan-bin zhao Shao-Kang Guan Dao-Kui Xu Cun-Guo Lin College of Materials Science and Engineering Shandong University of Science and Technology Qingdao 266590 China School of Materials Science and Engineering Zhengzhou University Zhengzhou 450002 China CAS Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China Science and Technology on Marine Corrosion and Protection Laboratory Qingdao 266071 China Qingdao Branch of Luoyang Ship Material Research Institute Qingdao 266101 China

Exfoliation on as-extruded Mg-1 Li-1 Ca magnesium alloy was investigated after an immersion in 3.5 wt%NaCl aqueous solution for 90, 120 and 150 days through optical microscope, digital camera, scanning electron microscope, electrochemical workstation, scanning Kalvin probe, X-ray diffraction and Fourier transform infrared spectroscope. The results demonstrated that exfoliation corrosion occurred on extruded Mg-1 Li-1 Ca alloy due to elongated microstructure parallel to surface, and delamination of lamellar structure resulted from galvanic effect and wedge effect. Skin layer with fine grains exhibited better corrosion resistance, whereas the interior with coarse grains and the intermetallic compound,Mg2 Ca particles existing in a fibrous structure, dispersed along grain boundaries and extrusion direction in a line. Furthermore, galvanic effect between Mg2 Ca particles and their neighboring a-Mg matrix facilitated dissolution of Mg2 Ca particles and a-Mg matrix; wedge effect was caused by formation of corrosion products. Exfoliation corrosion of extruded Mg-Li-Ca alloys might be a synergic effect of pitting corrosion,filiform corrosion, intergranular corrosion and stress corrosion. Finally, exfoliation corrosion mechanism was proposed.

关键词： Magnesium-lithium alloy Exfoliation corrosion Intermetallic compound Extrusion Microstructure

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Corrosion Resistance of Silane-Modified Hydroxyapatite Films on Degradable Magnesium Alloys

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Acta Metallurgica Sinica(English Letters) 2018年第2期31卷 180-188页

作者： yan-bin zhao Li-Qian Shi Lan-Yue Cui Chang-Lei Zhang Shuo-Qi Li Rong-Chang Zeng Fen Zhang Zhen-Lin Wang College of Materials Science and Engineering Shandong University of Science and Technology State Key Laboratory of Mining Disaster Prevention and Control Co-Founded by Shandong Province and the Ministry of Science and Technology Shandong University of Science and Technology College of Materials Science and Engineering Chongqing University of Technology

A polymethyltrimethoxysilane（PMTMS）/hydroxyapatite（HA） hybrid coating was successfully fabricated on a magnesium alloy by hydrothermal treatment and immersion method. The microstructure and composition of the coating were characterized by using X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron *** physical properties were investigated using scratch testing. At the same time, the corrosion resistance was evaluated via electrochemical and immersion tests. The results demonstrated that the corrosion resistance of the silane hybrid coating was significantly enhanced compared with the naked magnesium alloy. Especially, the corrosion current density of the PMTMS/HA magnesium alloy was three orders of magnitude lower than that of the bare material.

关键词： Magnesium alloys Silane Hydroxyapatite Corrosion resistance Biomaterial

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Genomes of Meniocus linifolius and Tetracme quadricornis reveal the ancestral karyotype and genomic features of core Brassicaceae

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Plant Communications 2024年第7期5卷 68-89页

作者： Jie Liu Shi-zhao Zhou Yun-Long Liu bin-yan zhao Dongmei Yu Mi-Cai Zhong Xiao-Dong Jiang Wei-Hua Cui Jiu-Xia zhao Juan Qiu Liang-Min Liu Zhen-Hua Guo Hong-Tao Li Dun-yan Tan Jin-Yong Hu De-Zhu Li CAS Key Laboratory for Plant Diversity and Biogeography of East Asia&Yunnan Key Laboratory of Crop Wild Relatives Omics Kunming Institute of BotanyChinese Academy of SciencesKunming 650201China Germplasm Bank of Wild Species&Yunnan Key Laboratory for Crop Wild Relatives Omics Kunming Institute of BotanyChinese Academy of SciencesKunming 650201China College of Life Sciences Xinjiang Agricultural UniversityÜrümqi 830052China University of Chinese Academy of Sciences Beijing 100049China These authors contributed equally to this article

Brassicaceae represents an important plant family from both a scientific and economic ***,genomic features related to the early diversification of this family have not been fully characterized,especially upon the uplift of the Tibetan Plateau,which was followed by increasing aridity in the Asian interior,intensifying monsoons in Eastern Asia,and significantly fluctuating daily ***,we reveal the genomic architecture that accompanied early Brassicaceae diversification by analyzing two high-quality chromosome-level genomes for Meniocus linifolius(Arabodae;clade D)and Tetracme quadricornis(Hesperodae;clade E),together with genomes representing all major Brassicaceae clades and the basal *** reconstructed an ancestral core Brassicaceae karyotype(CBK)containing 9 pseudochromosomes with 65 conserved syntenic genomic blocks and identified 9702 conserved genes in *** detected pervasive conflicting phylogenomic signals accompanied by widespread ancient hybridization events,which correlate well with the early divergence of core *** identified a successive Brassicaceae-specific expansion of the class I TREHALOSE-6-PHOSPHATE SYNTHASE 1(TPS1)gene family,which encodes enzymes with essential regulatory roles in flowering time and embryo *** TPS1s were mainly randomly amplified,followed by expression *** results provide fresh insights into historical genomic features coupled with Brassicaceae evolution and offer a potential model for broad-scale studies of adaptive radiation under an ever-changing environment.

关键词： Cruciferae genomic features ancient hybridization core Brassicaceae karyotype CBK TREHALOSE-6-PHOSPHATE SYNTHASE 1 genes TPS1s

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Corrosion resistance and antibacterial effects of hydroxyapatite coating induced by polyacrylic acid and gentamicin sulfate on magnesium alloy

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Frontiers of Materials Science 2019年第1期13卷 87-98页

作者： Xiao-Jing JI Qiang CHENG Jing WANG yan-bin zhao Zhuang-Zhuang HAN Fen ZHANG Shuo-Qi LI Rong-Chang ZENG Zhen-Lin WANG College of Materials Science and Engineering Shandong University of Science and TechnologyQingdao 266590China College of Materials Science and Engineering Chongqing University of TechnologyChongqing 400065China

Magnesium(Mg)alloys have attracted considerable research attention as potential biocompatible implant ***,the major barriers to the extended use of such medical devices are the possibility of high corrosion rate and implantassociated *** solve them,a novel polyacrylic acid(PAA)/gentamicin sulfate(GS)-hydroxyapatite(HAp)coating was synthesized by a one-step hydrothermal deposition *** of functional coatings were investigated by SEM,FTIR and *** properties of samples were evaluated by electrochemical and hydrogen evolution *** activities of the coatings against Staphylococcus aureus(***)were measured by the plate-counting *** showed that the as-prepared HAp coating with dense and flawless morphologies could not only enhance the corrosion resistance of Mg alloys,but also improve the adhesion strength between the HAp coating and the *** addition,the induction of the apatite coating during immersion confirmed the excellent mineralization ability of the HAp ***,the obtained HAp coati ng possessed antibacterial properties and could prolong the release of ***,the PAA/GS-HAp coated Mg alloy could serve as a better candidate for biomedical applications with good anti-corrosion and antibacterial properties.

关键词： magnesium alloy corrosion resistance antibacterial performance drug release hydroxyapatite coating

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Effect of endogenous hydrogen sulfide on oxidative stress in oleic acid-induced acute lung injury in rats

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Chinese Medical Journal 2011年第21期124卷 3476-3480页

作者： WANG Cong WANG Hai-ying LIU Zhi-wei FU yan zhao bin Department of Emergency Medicine Beijing Jishuitan Hospital Beijing 100035 China

Background Acute lung injury （ALl） is a common critical disease in emergency care. Oxidative stress plays an important role in the pathogenesis of ALl. Endogenous hydrogen sulfide （H2S） can inhibit oxidative stress in rat gastric mucosal epithelium. In this study, we examined the possible role of H2S in regulation of the oxidative stress in oleic acid-induced acute lung injury in rats. Methods The rat model of ALl was induced by intra-tail vein injection of oleic acid （CA）. NariS solution was injected intraperitoneally before CA injection as an CA＋NariS group. A semi-quantitative histological index of quantitative assessment of lung injury was calculated. The levels of superoxide dismutase （SOD）, glutathione （GSH） and malondialdehyde （MDA） in plasma and lung tissue were detected with ELISA. The levels of H2S content in lung tissue were detected with an ion meter. Results Compared with the control group, the level of H2S in lung tissue was significantly decreased, and the level of SOD and GSH were decreased but the level of MDA was increased in plasma and lung tissue in rats with ALl. NariS lessened the ALl in association with an increase in the level of H2S in lung tissue, a decrease in the level of MDA but an increase in SOD and GSH levels in plasma and lung tissues. Conclusion Endogenous H2S could inhibit the oxidative stress in lung tissue in oleic acid-induced acute lung injury in rats.

关键词： acute lung injury hydrogen sulfide oxidative stress

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Advances in layer-by-layer self-assembled coatings upon biodegradable magnesium alloys

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Science China Materials 2021年第9期64卷 2093-2106页

作者： Li-Jun He yang Shao Shuo-Qi Li Lan-Yue Cui Xiao-Jing Ji yan-bin zhao Rong-Chang Zeng Corrosion Laboratory for Light Metals College of Materials Science and EngineeringShandong University of Science and TechnologyQingdao266590China

Magnesium(Mg)and its alloys are considered as ideal biodegradable materials due to their excellent mechanical properties and *** order to improve the surface properties to allow better adaptation to the surrounding tissue of the body,surface modification has played a significant role in satisfying multiple clinical requirements such as corrosion resistance,biocompatibility,and antibacterial ***,layer-by-layer(LbL)self-assembly,which can be applied for biodegradable Mg alloys due to its extensive choice of usable units,holds great promise among all the surface *** this review,the mechanisms of the driving force(i.e.,electrostatic interaction,hydrogen bonding,charge transfer interaction and covalent bonding),cuttingedge advances in preparation methods(e.g.,dipping,spraying,and spinning)and the functional properties(corrosion resistance,antibacterial activity,and biocompatibility)that could be achieved by the LbL coatings are summarized.A reasonable trend of the potential development of LbL for bioMg alloys is also proposed at the end of this article.

关键词： layer-by-layer assembly coating magnesium alloys corrosion resistance biocompatibility antibacterial ability

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松辽盆地东北部铀矿含矿目的层泉头组物质来源及其构造背景分析——来自岩石学和地球化学的证据

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科学技术与工程 2020年第30期20卷 12324-12331页

作者：李研聂逢君严兆彬东华理工大学地球科学学院南昌330013 核工业240研究所沈阳110000

对于松辽盆地东北部地浸砂岩型铀矿找矿工作而言,赋铀砂体的物源是其关键,泉头组是重要的含矿目的层之一,明确其岩石学和地球化学特征,对于松辽盆地北部找矿具有十分重要的意义,通过对松辽盆地东北部10件砂岩样品进行岩石学研究、稀土... 详细信息

对于松辽盆地东北部地浸砂岩型铀矿找矿工作而言,赋铀砂体的物源是其关键,泉头组是重要的含矿目的层之一,明确其岩石学和地球化学特征,对于松辽盆地北部找矿具有十分重要的意义,通过对松辽盆地东北部10件砂岩样品进行岩石学研究、稀土元素、微量元素的分析测试工作,可知泉头组碎屑岩主要以长石岩屑砂岩为主,其碎屑岩成分成熟度和结构成熟度均较低,具有近物源沉积的特征,岩石稀土总量不高(ΣREE=84.85×10^-6~140.12×10^-6),轻稀土分馏系数(La/Sm)N=3.57~4.12,重稀土分馏系数(Gd/Yb)N=2.13~2.67,Eu为中等负异常(δEu=0.57~0.96),微量元素以富集LREE、Rb、Th、U、K,强烈亏损Sr、P、Ti为特征,具有壳源特征,且在源区和构造判别图解上分别落入长英质源区及活动大陆边缘区域内,显示泉头组物源主要来源于上地壳长英质岩石,其母岩的沉积环境是与活动大陆边缘相关的沉积盆地。

关键词：泉头组岩石学地球化学松辽盆地东北部

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Contrastive Research on Domestic and Foreign Ecological Agriculture Policies

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Asian Agricultural Research 2010年第10期2卷 1-4,8页

作者： CHEN Jia-wei,QI yan-bin,zhao Yu-feng College of Economics and Management,Sichuan Agricultural University,Ya’an 625014,China

In the first place,the definitions of ecological agriculture defined by scholars both at home and abroad are *** the second place,the domestic and foreign ecological agriculture policies are *** contrastive research on the domestic and foreign ecological agriculture polices,the problems in the development of ecological agriculture in China are *** mirroring the western experiences in developing ecological agriculture,the countermeasures and relevant suggestions are put forward from the perspective of *** first one is to increase the subsidies from the government to ecological *** second one is to clarify the standard of ecological agriculture *** third one is to promote the industrialization of ecological *** fourth one is to strengthen the construction of ecological demonstration region and ecological village.

关键词： Ecological agriculture Policies Agricultural subsi

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不同形貌金纳米粒子的制备及其表面增强拉曼散射效应的研究

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光谱学与光谱分析 2017年第1期37卷 7-12页

作者：苏晓越陈小燕孙成彬赵冰阮伟东吉林大学超分子结构与材料国家重点实验室吉林长春130012

不同形状的金纳米粒子在表面增强拉曼散射(surface enhanced Raman scattering,SERS)中有不同的增强效果,多面体金纳米粒子具有多角结构,显示出比金纳米板更为明显的增强效果,近年来对其合成和性质的研究备受关注。该研究探究了十二面体... 详细信息

不同形状的金纳米粒子在表面增强拉曼散射(surface enhanced Raman scattering,SERS)中有不同的增强效果,多面体金纳米粒子具有多角结构,显示出比金纳米板更为明显的增强效果,近年来对其合成和性质的研究备受关注。该研究探究了十二面体,二十面体,三角板,球形四种形状的金纳米粒子在SERS中不同的增强效果。分别采用硼氢化钠还原法和以N,N-二甲基甲酰胺(DMF)为还原剂制备金三角纳米片和二十面体金纳米粒子,又以二十面体金纳米粒子为种子制备出十二面体金纳米粒子,并分别以以上三种不同形貌的金纳米粒子及球形金溶胶为基底,4-巯基吡啶,对巯基苯甲酸为探针分子检测了其在不同激发波长下的增强效果。透射电子显微镜结果表明金三角纳米板的平均边长为130nm,二十面体和十二面体金纳米粒子的粒径分别为100和120nm。三者的紫外可见吸收峰分别在589,598和544nm处。表面增强拉曼散射结果表明金多面体比金三角纳米板表现出更好的增强效果。

关键词：金纳米粒子形貌 SERS

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伪谱算法在声波数值模拟中的数值频散分析

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地震 2017年第2期37卷 135-146页

作者：武晔赵晓燕石砚斌俞子钊何欣娟胡泊熊仲华防灾科技学院河北燕郊101601

本文推导了声波方程频散函数,分析了伪谱法的空间网格大小和采样周期对数值频散的影响,通过数值模拟实验得到了最佳空间参数选择方法。结果表明:伪谱方法稳定数值模拟的最大空间采样间距选取原则是使中波长(奈奎斯特频率的一半)的采样... 详细信息

本文推导了声波方程频散函数,分析了伪谱法的空间网格大小和采样周期对数值频散的影响,通过数值模拟实验得到了最佳空间参数选择方法。结果表明:伪谱方法稳定数值模拟的最大空间采样间距选取原则是使中波长(奈奎斯特频率的一半)的采样点数为2个;对于所有维度,稳定性随空间采样间距的增加而增加,但不易变化太大,变化太大时需要适当减小震源子波的主频,以满足空间合理采样;空间采样间距的大小设置,需要考虑满足采样定理和稳定性计算条件,并且稳定性条件对空间采样间距的要求更加严格;伪谱法数值模拟的最佳(数值频散最小)空间参数选择为中波长2个采样点,对应主波长约6~7个采样点。以上研究对于采用伪谱法进行声波方程数值模拟过程中,如何合理选择模拟参数提供一些参考。

关键词：数值频散伪谱法数值模拟声波

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