检索结果-南通市图书馆

Zircon U-Pb ages and geochemistry of the Huai'an TTG gneisses terrane:Petrogenesis and implications for ～2.5 Ga crustal growth in the North China Craton

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Zircon U-Pb ages and geochemistry of the Huai'an TTG gneisse...

中国科学院地质与地球物理研究所2012年度（第12届）学术年会

作者： Fu Liu jing-hui guo Peng Peng Qing Qian State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of Sciences

The Huai’an gneiss terrane is a typical Archean terrane within the Trans-North China Orogen of the North. China Craton(NCC) and is composed of Tonalite-Trondhjemite-Granodiorite(TTG) suite and dioritic granulite fades *** SHRIMPII and Cameca 1MS1280 zircon U-Pb ages demonstrate that the Huai’an gneisses formed around 2.55-2.50 Ga and underwent granulite fades metamorphism at 1,85-1.80 *** TTG gneisses are compositionally equivalent to high-SiO adakites,with high SiO and AlO concentrations,strongly fractionated rare earth element(REE) patterns((La/Yb)N = 10-54) with positive or negligible Eu anomalies(Eu/Eu* = 0.9-3.4),low heavy REE(HREE) and Y concentrations, high Sr(435-938 ppm) concentrations,and high Sr/Y ratios(48-261).High Mg numbers(33-60) and high compatible element concentrations(e.g.,Cr = 11-183ppm and Ni=11-82ppm) indicate that the magmas that formed these gneisses were derived from interaction between adakitic melts and mantle *** dioritic gneisses have compositions similar to high-Mg diorites or sanukitoids,with high AlO(14.46-17.61 wt%),MgO(3.0-6.4 wt%),Cr(100-304 ppm),and Ni(57-109ppm) concentrations, and fractionated REE patterns with weak negative or no Eu anomalies(Eu/Eu = 0.8-1.0).All the TTG and dioritic gneiss samples analysed during this study have negative Nb,Ta,and Ti anomalies,compared to neighbouring elements in spider-diagrams,with the majority having high positiveε(t) andε(t) values, close to values of the depleted *** geochemical characteristics strongly suggest that protoliths of the Huai’an TTG and dioritic gneisses originated in a juvenile crust-forming event at 2.55-2.50Ga through partial melting of subducted oceanic crustal material;these magmas also assimilated mantle peridotite material during their *** indicates that .5Ga mantle-derived magmatism led to significant crustal growth in the North China Craton,and was probably associated with subduction.

关键词： TTG gneisses Dioritic gneiss 2.5 Ga crnstal growth Huai’an gneiss terrane Late Archean North China Craton

Unraveling brain aging through the lens of oral microbiota

在线全文

cnki会议

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第7期20卷 1930-1943页

作者： Qinchao Hu Si Wang Weiqi Zhang jing Qu Guang-hui Liu State Key Laboratory of Membrane Biology Institute of ZoologyChinese Academy of SciencesBeijingChina Hospital of Stomatology Guanghua School of StomatologyGuangdong Provincial Key Laboratory of StomatologySun Yat-sen UniversityGuangzhouGuangdong ProvinceChina Advanced Innovation Center for Human Brain Protection and National Clinical Research Center for Geriatric Disorders Xuanwu HospitalCapital Medical UniversityBeijingChina Aging Translational Medicine Center International Center for Aging and CancerBeijing Municipal Geriatric Medical Research CenterXuanwu HospitalCapital Medical UniversityBeijingChina CAS Key Laboratory of Genomic and Precision Medicine Beijing Institute of GenomicsChinese Academy of Sciences and China National Center for BioinformationBeijingChina University of Chinese Academy of Sciences BeijingChina Institute for Stem Cell and Regeneration Chinese Academy of SciencesBeijingChina Aging Biomarker Consortium BeijingChina State Key Laboratory of Stem Cell and Reproductive Biology Institute of ZoologyChinese Academy of SciencesBeijingChina Beijing Institute for Stem Cell and Regenerative Medicine BeijingChina

The oral cavity is a complex physiological community encompassing a wide range of *** of oral microbiota can lead to various oral infectious diseases,such as periodontitis and tooth decay,and even affect systemic health,including brain aging and neurodegenerative *** studies have highlighted how oral microbes might be involved in brain aging and neurodegeneration,indicating potential avenues for intervention *** this review,we summarize clinical evidence demonstrating a link between oral microbes/oral infectious diseases and brain aging/neurodegenerative diseases,and dissect potential mechanisms by which oral microbes contribute to brain aging and *** also highlight advances in therapeutic development grounded in the realm of oral microbes,with the goal of advancing brain health and promoting healthy aging.

关键词： Alzheimer's disease brain aging multiple sclerosis neurodegeneration neurodegenerative diseases oral microbiota Parkinson's disease periodontitis bacteria Porphyromonas gingivalis

Short-lived high-temperature prograde and retrograde metamorphism in Shaerqin sapphirine-bearing metapelites from the Daqingshan terrane,North China Craton

在线全文

学校读者我要写书评

暂无评论

Short-lived high-temperature prograde and retrograde metamor...

中国科学院地质与地球物理研究所2015年度（第15届）学术年会

作者： Shu-Juan Jiao jing-hui guo Luo-Juan Wang Peng Peng State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of Sciences

The tectonic mechanism responsible for the formation of high-temperature(HT)and ultrahightemperature(UHT)granulites(>850?C)at moderate pressure(7–13 kbar)is diverse and contentious,ranging from hot back-arc inversion and thickening,to lithospheric extension and underplating/intrusion of mafic magma,long-lived orogenic self-heating,and ridge *** fundamental reason for this is partly related to the fact that the prograde mineral assemblage and growth zoning are difficult to perserve due to HT diffusion,strong deformation and fluid/melt ***,the prograde heating reaction footprint is most likely preserved during a rapid tectonothermal *** the current paper,we discovered large-scale Spr-bearing metapelites that were originally Sil-Bt metapelite(M1)and preserved secondly Spr+Mag(M2)assemblage at the Shaerqin locality in the Daqingshan terrane of the North China *** is later replaced by spinel and cordierite corona(M3),all of which were further back-reacted and overprinted by fibrous sillimanite and retrograde biotite(M4).The well-preserved multistage prograde and retrograde mineral assemblages suggest a rapid tectonothermal process.A clockwise P-T path is confined with peak conditions of 860–890?C and 7.5–8.5 kbar,by phase equilibria modeling in the NCKFMASHTO *** involves a prograde heating evolution(possibly with slight decompression),a post-peak limited isothermal decompression,and a final isobaric cooling *** zircon and monazite U-Th-Pb dating constrained the near-peak metamorphic age of ca.1.86 *** rapid process recorded in the Spr-bearing metapelite at ca.1.86 Ga is likely caused by heating of the mantle-derived magma and controlled by an extension mechanism at the termination of the Paleoproterozoic continental–continental(or arc)collision during the amalgamation of the NCC.

关键词： Geochronology High-temperature North China Craton Pseudosection Sapphirine Short-lived

Catalytic Performance of Carbon Smoke over Ag-LSCF Composite Catalysts

在线全文

cnki会议

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2025年第1期40卷 30-34页

作者： guo Guanlun HAN Ming LU Shaomin YU jing JU Hongling 无 Hubei Key Laboratory of Advanced Technology for Automotive Components&Hubei Collaborative Innovation Center for Automotive Components Technology Wuhan University of TechnologyWuhan 430070China College of Mechanical and Transportation Southwest Forestry UniversityKunming 650000China

To improve the catalytic performance of La_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3)(LSCF)towards carbon soot,we utilized the impregnation method to incorporate Ag into the prepared LSCF *** conducted a series of characterization tests and evaluated the soot catalytic activity of the composite catalyst by comparing it with the LaCoO_(3) group,LaFeO_(3) group,and catalyst-free *** results indicate that the Ag-LSCF composite catalyst exhibits the highest soot catalytic activity,with the characteristic temperature values of 376.3,431.1,and 473.9℃at 10%,50%,and 90%carbon soot conversion,*** values are 24.8,20.2,and 23.1℃lower than those of the LSCF *** also shows that LSCF can improve the catalytic activity of soot after compounding with Ag,and reflects the necessity of using catalysts in soot combustion *** characterization and BET test show that Ag-LSCF has more abundant surface-adsorbed oxygen species,larger specific surface area and pore volume than LSCF,which also proves that Ag-LSCF has higher soot catalytic activity.

关键词： metallic composites carbon smoke oxidation perovskite catalyst soot

Effects of the extrusion parameters on microstructure,texture and room temperature mechanical properties of extruded Mg-2.49Nd-1.82Gd-0.2Zn-0.2Zr alloy

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 136-146页

作者： Chenjin Zhang Guangyu Yang Lei Xiao Zhiyong Kan jing guo Qiang Li Wanqi Jie State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China College of Materials Science and Engineering Fuzhou UniversityFuzhou 350108China College of Chemistry and Environmental Science Qujing Normal UniversityQujing 655011China

Microstructure,texture,and mechanical properties of the extruded Mg-2.49Nd-1.82Gd-0.2Zn-0.2Zr alloy were investigated at different extrusion temperatures(260 and 320℃),extrusion ratios(10:1,15:1,and 30:1),and extrusion speeds(3 and 6 mm/s).The experimental results exhibited that the grain sizes after extrusion were much finer than that of the homogenized alloy,and the second phase showed streamline distribution along the extrusion direction(ED).With extrusion temperature increased from 260 to 320℃,the microstructure,texture,and mechanical properties of alloys changed *** dynamic recrystallization(DRX)degree and grain sizes enhanced as the extrusion ratio increased from 10:1 to 30:1,and the strength gradually decreased but elongation(EL)*** the extrusion speed increased from 3 to 6 mm/s,the grain sizes and DRX degree increased significantly,and the samples presented the typical-rare-earth(RE)*** alloy extruded at 260℃ with extrusion ratio of 10:1 and extrusion speed of 3 mm/s showed the tensile yield strength(TYS)of 213 MPa and EL of 30.6%.After quantitatively analyzing the contribution of strengthening mechanisms,it was found that the grain boundary strengthening and dislocation strengthening played major roles among strengthening *** results provide some guidelines for enlarging the industrial application of extruded Mg-RE alloy.

关键词： Mg-rare earth alloys extrusion temperature extrusion ratio extrusion speed strengthening mechanisms

Unraveling the significance of cobalt on transformation kinetics,crystallography and impact toughness in high-strength steels

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 380-390页

作者： Yishuang Yu jingxiao Zhao Xuelin Wang hui guo Zhenjia Xie Chengjia Shang Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing 100083China School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijing 100083China

This work reveals the significant effects of cobalt(Co)on the microstructure and impact toughness of as-quenched highstrength steels by experimental characterizations and thermo-kinetic *** results show that the Co-bearing steel exhibits finer blocks and a lower ductile-brittle transition temperature than the steel without ***,the Co-bearing steel reveals higher transformation rates at the intermediate stage with bainite volume fraction ranging from around 0.1 to *** improved impact toughness of the Co-bearing steel results from the higher dense block boundaries dominated by the V1/V2 variant ***,the addition of Co induces a larger transformation driving force and a lower bainite start temperature(BS),thereby contributing to the refinement of blocks and the increase of the V1/V2 variant *** findings would be instructive for the composition,microstructure design,and property optimization of high-strength steels.

关键词： high-strength steel cobalt transformation kinetics crystallography impact toughness

Ce-Nd separation by solid-phase micro-extraction and its application to high-precision 142Nd/144Nd measurements using TIMS in geological materials

在线全文

学校读者我要写书评

暂无评论

Ce-Nd separation by solid-phase micro-extraction and its app...

中国科学院地质与地球物理研究所2015年度（第15届）学术年会

作者： Chao-Feng Li Xuan-Ce Wang You-Lian Li Zhu-Yin Chu jing-hui guo Xiang-hui Li State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of Sciences The Institute for Geoscience Research(TIGer) Curtin University Isotope Research Institute of Henan Academy of Sciences Co.Ltd

In view of the low initial abundance ofSm,Nd anomalies are expected to be extremely small(less than40 ppm),and their detection requires ultra-preciseNd/Nd measurements.A rapid solid-phase microextraction(SPME)technique,using HEHEHP resin as sorbent,is established to completely separate Ce from rare earth element(REE)*** technique is applied to ultra-high-precisionNd/Nd measurements in geological materials,In contrast to the traditional liquid-liquid micro-extraction(LLME)technique,the benefits of the SPME tandem column are high Nd recovery,low residual Ce(Ce/Nd3.0,Thus,Ce interferences onNd never exceed 1.3 ***-high-precision thermal ionization mass spectrometry analyses of silicate standards show that the internal precision of all runs are better than 4 ppm(2 RSE)forNd/Nd ***/Nd values for JNdi-1,JR-3,and BCR-2 have external precisions of±4.8,±4.4,and±3.9 ppm(2 RSD),*** external reproducibility is sufficient to distinguish and resolve 5 ppm anomalies inNd/Nd values.

关键词：

A rapid single column separation scheme for highprecision Sr-Nd-Pb isotopic analysis in geological samples using thermal ionization mass spectrometry

在线全文

cnki会议

学校读者我要写书评

暂无评论

A rapid single column separation scheme for highprecision Sr...

中国科学院地质与地球物理研究所2015年度（第15届）学术年会

作者： Chao-Feng Li Zhu-Yin Chu jing-hui guo You-Lian Li Yue-Heng Yang Xiang-hui Li State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of Sciences Isotope Research Institute of Henan Academy of Sciences Co.Ltd

Thermal ionization mass spectrometry(TIMS) is considered the most accurate technique for determining Sr-Nd-Pb isotopic ratios in geological ***,time-consuming and complex sample separation procedures greatly hinder the instrumental measurement *** this study,a singlecolumn separation chemistry procedure for Sr-Nd-Pb from single rock dissolution was *** chemistry procedure was designed to minimize the number of evaporation steps and considerably shorten the separation time,enabling high throughput for *** contrast to conventional threecolumn separation procedures( days),this technique was characterized by high efficiency superiority in terms of separation time( hours),a 3-fold enhancement in the separation *** stability of our procedure was demonstrated by replicated TIMS measurements of Sr/Sr,Nd/Nd,pb/pb,pb/pb and Pb/pb ratios for six international silicate rock reference materials,spanning a wide range of bulk *** analytical results obtained for these standards agreed well with published *** external reproducibility(2 RSD,n = 10) of a BCR-2 standard sample was±0.0020% for Sr/Sr,±0.0023%for Nd/Nd,and ±0.021-0.033% for Pb/Pb,Pb/Pb and Pb/Pb ratios.

关键词：

Rapid and precise determination of Sr and Nd isotopic ratios in geological samples from the same filament loading by thermal ionization mass spectrometry employing a single-step separation scheme

在线全文

cnki会议

学校读者我要写书评

暂无评论

Rapid and precise determination of Sr and Nd isotopic ratios...

中国科学院地质与地球物理研究所2012年度（第12届）学术年会

作者： Chao-Feng Li Xian-Hua Li Qiu-Li Li jing-hui guo Xiang-hui Li Yue-Heng Yang State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of Sciences School of Earth Sciences Graduate University of Chinese Academy of Sciences

Thermal ionization mass spectrometry(TIMS) offers the excellent precision and accuracy of the Sr and Nd isotopic ratio analysis for geological samples,but this method is labour intensive,expensive and *** this study,a new analytical protocol by TIMS is presented that aims at improving analytical efficiency and cutting down experimental *** the single-step cation exchange resin technique,mixed Srand rare earth elements(REEs) fractions were separated from matrix and evaporated to ***,mixed Sr + REEs fractions were dissolved and loaded onto the same Re filament using 1μl of 2 M ***,Sr and Nd were sequentially measured without venting using *** contrast to conventional TIMS methods,the merits of this analytical protocol are its cost- and timesaving *** applicability of ourmethod is evaluated by replicated measurements of Sr/Sr and Nd/Nd for nine international silicate rock reference materials,spanning a wide range of bulk *** typical internal precision in this study is ca.0.001%(RSE)for Sr/Sr and Nd/Nd;the analytical results obtained for these standard rocks show a good agreement with reported values, indicating the effectiveness of the proposed method.

关键词： Geological sample Sr-Nd isotopes Extraction chromatography Thermal ionization mass spectrometry