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Deformation temperature and postdeformation annealing effects on severely deformed TiNi alloy by equal channel angular extrusion

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Journal of University of Science and Technology Beijing 2007年第6期14卷 533-537页

作者： Zhenhua li xianhua Cheng School of Mechanical and Power Engineering Shanghai Jiaotong University Shanghai 200030 China

Micron TiNi alloy blocks were fabricated at high temperature by equal channel angular extrusion （ECAE） using hotforged Ti-50.3at%Ni alloy as the raw material and the effects of deformation temperature and postdeformation annealing on the severely deformed TiNi alloy by ECAE were investigated. The results show that the TiNi alloy processed by ECAE undergoes severe plastic deformation, and lowering the deformation temperature and increasing the number of extrusions contribute to grain refinement. When the annealing temperature is below 873 K, static recovery is the main restoration process; when the temperature rises to 973 K, static recrystallization occurs. It is found that fine particles are precipitated when the TiNi alloy processed by ECAE is annealed at 773 K.

关键词： TiNi shape memory alloy equal channel angular extrusion (ECAE) static recrystallization ultrafine-grained (UFG) structure

On Weakly s-Semipermutable Subgroups of Finite Groups

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Algebra Colloquium 2014年第4期21卷 541-550页

作者： Na Tang xianhua li School of Mathematics Science Soochow University Suzhou Jiangsu 215006 China

We prove that a finite group G is p-supersolvable or p-nilpotent if some sub- groups of G are weakly s-semipermutable in G. Several earlier results are generalized.

关键词： weakly s-semipermutable subgroup p-nilpotent group p-supersolvable group

Effect of Al(OH)_(3) prepared from fly ash on the structural and catalytic properties of g-C_(3)N_(4)-based materials

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Chinese Journal of Chemical Engineering 2024年第10期74卷 44-51页

作者： Qingbo Yu xianhua li Qingping Wang The First Affiliated Hospital of Anhui University of Science and Technology(Huainan First People's Hospital) Anhui University of Science and TechnologyHuainan 232001China Anhui Industrial Generic Technology Research Center for New Materials from Coal-based Solid Wastes Huainan 232001China School of Materials Science and Engineering Anhui University of Science and TechnologyHuainan 232001China

In order to find the optimal combination method of secondary utilization of fly ash and graphite-phase carbon nitride(g-C_(3)N_(4))modification,an efficient composite photocatalyst of γ-Al_(2)O_(3)/g-C_(3)N_(4)was obtained by calcining the composite precursors of Al(OH)3/dicyandiamide(DCDA).The introduction of Al(OH)_(3)prepared by combining fly ash into the precursors causes hydrogen-bonding interactions between Al(OH)_(3)and DCDA,which facilitate the removal of N atoms from the edges of the CN framework of g-C_(3)N_(4)during condensation,and the composites prepared possess more cyano *** addition,γ-Al_(2)O_(3)and g-C_(3)N_(4)form a chemical bond at the interface,and this chemical bonding causes the density of the electron cloud in the vicinity of the N atoms to *** them,the strongest chemical bonding between Al_(2)O_(3)and g-C_(3)N_(4)was observed in ACN-1,whereas the most cyanine defects were formed in ACN-1,which made ACN-1 exhibit the best photocatalytic degradation of methylene blue,which is 2.48 times higher than that of the pristine g-C_(3)N_(4).

关键词： Precursors g-C_(3)N_(4) Waste treatment Catalyst Synthesis

SHRIMP U-Pb zircon age,geochemistry and Nd-Hf isotope of Neoproterozoic mafic dyke swarms in western Sichuan:Petrogenesis and tectonic significance

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Science China Earth Sciences 2007年第1期50卷 1-16页

作者： liN GuangChun li xianhua li WuXian Key Laboratory of Isotope Geochronology and Geochemistry Guangzhou Institute of GeochemistryChinese Academy of SciencesGuangzhou 510640China Graduate University of the Chinese Academy of Sciences Beijing 100039China

Neoproterozoic magmatic rocks are widespread in the western margin of the Yangtze block, and their origin and genesis have significant implications for understanding the evolution of the Rodinia super- continent. However, there are currently two opposing interpretations for their petrogenesis and tectonic setting: mantle plume-related and island arc origin. To further verify these two competing models, SHRIMP U-Pb zircon age determinations and geochemical and Nd-Hf isotopic analyses are conducted on the mafic dykes in the Kangdian Rift, western Sichuan. U-Pb dating suggests that these mafic dykes were emplaced at 780―760 Ma, spatially and temporally coeval with the Kangding granitoid complex. The parental magmas of these dykes were derived from a depleted asthenosphere mantle source likely triggered by an anomalously-hot mantle plume. Despite some arc-geochemical features caused by variable degrees of contamination of young island arc crust during magma ascending and emplace- ment, they show general geochemical and Nd-Hf isotopic features similar to those of the intraplate basalts. Our results support the reconstruction model of Rodinia in which the South China block was located between Australia and Laurentia.

关键词： Neoproterozoic mafic dykes Kangdian Rift South China Rodinia

Minimal inner-Σ-Ω-groups and their applications

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Science China Mathematics 2011年第9期54卷 1927-1936页

作者： li xianhua XU Yong School of Mathematical Science Soochow University Suzhou 215006 China

We introduce and study the minimal inner-Σ-Ω-groups and the minimal outer-Σ-■-*** we give some applications and obtain some interesting results,including characterizations of nilpotent,supersolvable,solvable,and p... 详细信息

关键词： nilpotent subgroup supersolvable subgroup a pair of conjugate subgroups minimal inner-∑-Ω- group

On the genetic classification and tectonic implications of the Early Yanshanian granitoids in the Nanling Range, South China

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Chinese Science Bulletin 2007年第14期52卷 1873-1885页

作者： li xianhua li WuXian li Zheng-Xiang Key Laboratory of Isotope Geochronology and Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 China State Key Laboratory of lithospheric Evolution Institute of Geology and Geophysics Chinese Acadamy of Sciences Beijing 100029 China Institute of Geoscience Research Department of Applied Geology Curtin University of Technology GPO Box U 1987 Perth WA 6845 Australia

Early Yanshanian (Jurassic) granitoids are widespread in the Nanling Range of South China, and are associated with numerous non-ferrous and rare metal mineral deposits. These granitoids consist mainly of slightly peraluminous biotite monzogranites and K-feldspar granites that are closely associated in time and space with subordinate amphibole-bearing granites and muscoviteand garnet-bearing granites. In most previous studies, the biotite-bearing granites were classified as crustal transformation-type (corresponding to the S-type) granites which were interpreted to be derived from the regional Paleoproterozoic meta-sedimentary rocks. In this paper, we re-analyze the geochemical characteristics of a number of representative Early Yanshanian Nanling granitoids. There exists a clear negative correlation between SiO2 and P2O5 for the studied granitoids. The Early Yanshanian Nanling granitoid suites (including amphibole-bearing granodiorites→biotite monzogranites→K-feldspar granites→two-mica (muscovite) granites) are metaluminous to slightly peraluminous I-type or fractionated I-type granites. They were derived predominantly from Proterozoic igneous protoliths. The juvenile crust and/or newly mantle-derived materials might also have been involved in some of these granites. In addition, the Iand fractionated I-type granites are closely associated in time and space with minor amount of A-type felsic and mafic volcanic and intrusive rocks as well as alkaline rocks. All these rocks constitute a typical assemblage of anorogenic, intraplate magmatism, suggesting a dominant lithospheric extensional regime for the Nanling Range and neighboring region during the Early Yanshanian period.

关键词：遗传分类燕山期地质学人造花岗岩面中国

Long-Term Reproducibility of SIMS Zircon U-Pb Geochronology

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Journal of Earth Science 2022年第1期33卷 17-24页

作者： Wenhao Zhao Qiuli li Yu liu Guoqiang Tang Xiaoxiao ling Jiao li xianhua li State Key Laboratory of lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China Innovation Academy for Earth Science Chinese Academy of SciencesBeijing 100029China

Secondary ion mass spectrometry(SIMS) zircon U-Pb dating has been widely used to confine the absolute ages of the magmatic or metamorphic events and to distinguish multiple ***,a data set consisting of the zircon standards dating data(~15 000 Ple?ovice and ~8 000 Qinghu items) accumulated for more than 8 years using the CAMECA IMS 1280 HR of the Institute of Geology and Geophysics,Chinese Academy of Sciences(IGGCAS) is compiled to evaluate the long-term external *** Ple?ovice zircon as the calibration standard and Qinghu zircon as an unknown sample,the analytical uncertainties for single-spot(n = 7 723) and session analyses(n = 691,with more than 7 single spot analyses in one session) are 2.6% and 0.9%(2 RSD,relative standard deviation),*** means that single-spot U-Pb dating for a standard-level zircon sample could vary 5.2% at 95% confidence level,while the average value(n > 7) for each session may vary 1.8%.Thus,these values should be considered as the minimum uncertainty when comparing single spot and individual session analysis results for multiple dating works on a certain geological event.

关键词： zircon U-Pb dating SIMS uncertainty reproducibility

Multi-Branch High-Dimensional Guided Transformer-Based 3D Human Posture Estimation

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Computers, Materials & Continua 2024年第3期78卷 3551-3564页

作者： xianhua li Haohao Yu Shuoyu Tian Fengtao lin Usama Masood School of Mechanical Engineering Anhui University of TechnologyHuainan232001China School of Artificial Intelligence Anhui University of TechnologyHuainan232001China Key Laboratory of Conveyance Equipment(East China Jiaotong University) Ministry of EducationNanchang330013China

The human pose paradigm is estimated using a transformer-based multi-branch multidimensional directed the three-dimensional(3D)method that takes into account self-occlusion,badly posedness,and a lack of depth data in the per-frame 3D posture estimation from two-dimensional(2D)mapping to 3D ***,by examining the relationship between the movements of different bones in the human body,four virtual skeletons are proposed to enhance the cyclic constraints of limb ***,multiple parameters describing the skeleton are fused and projected into a high-dimensional *** a multi-branch network,motion features between bones and overall motion features are extracted to mitigate the drift error in the estimation ***,the estimated relative depth is projected into 3D space,and the error is calculated against real 3D data,forming a loss function along with the relative depth *** article adopts the average joint pixel error as the primary performance *** to the benchmark approach,the estimation findings indicate an increase in average precision of 1.8 mm within the Human3.6M sample.

关键词： Key point detection 3D human posture estimation computer vision deep learning

Insights into the origin of purely sediment-derived Himalayan leucogranites:Si-O isotopic constraints

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Science Bulletin 2018年第19期63卷 1243-1245页

作者： Xiaochi liu xianhua li Yu liu Lei Yang Qiuli li Fuyuan Wu Huimin Yu Fang Huang State Key Laboratory of lithospheric Evolution Institute of Geology and Geophysics Chinese Academy of Sciences College of Earth and Planetary Sciences University of Chinese Academy of Sciences CAS Key Laboratory of Crust-Mantle Materials and Environments School of Earth and Space Sciences University of Science and Technology of China

Granite is the dominant rock type in Earth’s continental *** origin of granite can be directly or indirectly related to the fractional crystallization of mantle-derived basaltic melt or the reworking of pre-existing continental or oceanic crust, which contribute to the growth of continental crust. Among the various types of granites, the peraluminous leucogranites in the Himalayan orogen, which are high in SiO_2(>73%) and low in mafic minerals (<5%),

关键词：起源同位素沉积岩石类型花岗石外壳大陆玄武岩