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Late neoproterozoic to early Cambrian high-grade metamorphism from Mikir Hills(Assam-Meghalaya gneissic Complex,northeast India):Implications for eastern Gondwana assembly

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Geoscience Frontiers 2024年第5期15卷 256-282页

作者： Rahul nag H.Hrushikesh nathan Cogné n.Prabhakar Department of Earth Sciences Indian Institute of Technology BombayPowaiMumbaiMaharastra 400076India Geological Survey of India Northeastern RegionGuwahatiAssam 781005India Géosciences Rennes UMR6118CNRS Universitéde RennesFrance

Mikir Hills region,which represents the eastern segment of the Assam-Meghalaya Gneissic Complex(AMGC)in northeast India,constitutes part of the Eastern *** Mikir Hills preserves multiple metamorphic and magmatic events ranging from Early Mesoproterozoic to Early *** of these events,documenting the late neoproterozoic to early Cambrian tectonothermal events is helpful in correlating the continental blocks of Eastern *** present an integrated study involving field relations,petrology,P-T history and zircon-monazite geochronology of hitherto poorly studied pelitic and quartzo-feldspathic gneisses from the Mikir Hills *** gneisses have experienced at least three deformation events(D_(1),D_(2) and D_(3.)with dominant foliation indicated by EnE-WSW striking and shallow-moderately dipping(neissic *** peak metamorphism in pelitic and quartzo-feldspathic gneisses is characterized by garnet(core)-K-feldspar-sillimanite-plagioclase-bio tite-rutile-quartz-ilmenite-melt and garnet-plagioclase-K-feldspar-biotite-quartz-ilmenite-melt assemblages,*** application of thermobarometric methods constrains the peak P-T conditions of 7.5-8.4 kbar at 674-778℃and 6.7-7.4 kbar at 601-618℃for pelitic and quartzofeldspathic gneisses,*** results are consistent with the values estimated using phase equilibria modelling and melt reintegration *** results of pseudosection modelling suggests a clockwise P-T path for pelitic gneisses involving migmatisation during peak metamorphism followed by near isothermal decompression from 8.0 to 8.6 kbar at 768-780℃to 4.0-5.0 kbar at 720-765℃.In contrast,quartzo-feldspathic gneisses preserved slightly lower peak P-T conditions at 3.8-4.6 kbar and 590-650℃.The U-Pb zircon dating of migmatised pelitic and quartzo-feldspathic gneisses yielded concordant ages of 1647±11 Ma and 1590±7 Ma,*** dates represent the inherited igneous protolith components,possibly

关键词： Gondwana Assam-Meghalaya Gneissic Complex Migmatisation neoproterozoic Geochronology P-T-t history

Measurement of yields and angular distributions ofγ-quanta from the interaction of 14.1 MeV neutrons with oxygen,phosphorus,and sulfur

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Chinese Physics C 2024年第3期48卷 79-92页

作者： D.n.Grozdanov n.A.Fedorov S.B.Dabylova Yu.n.Kopatch I.n.Ruskov V.R.Skoy T.Yu.Tretyakova C.Hramco P.I.Kharlamov G.V.Pampushik P.G.Filonchik A.V.Andreev Joint Institute for nuclear Research(JInR) DubnaRussia Institute for nuclear Research and nuclear Energy Bulgarian Academy of SciencesSofiaBulgaria Faculty of Physics Lomonosov Moscow State UniversityMoscowRussia L.n.Gumilyov Eurasian national University AstanaKazakhstan Skobeltsyn Institute of nuclear Physics Moscow State UniversityMoscowRussia Institute of Chemistry of Moldova ChisinauRepublic of Moldova Moscow Institute of Physics and Technology MoscowRussia

A study of the inelastic scattering of neutrons with an energy of 14.1 MeV on the nuclei of oxygen,phosphorus,and sulfur was performed at the TAnGRA facility at JInR(Dubna).The experiment aimed to refine existing data and obtain new data on the yields and angular distributions ofγ-quanta emitted by the studied nuclei due to neutron-induced nuclear reactions using the tagged neutron *** types of detector systems were used to registerγ-***γ-ray yields were measured using a high-purity germanium(HPGe)*** angular distributions ofγ-rays were obtained using a system of 18 scintillation detectors based on bismuth germanite Bi_(4)Ge_(3.O_(12)(BGO)located around the *** performed experiments measured the yields of two transitions for the reaction of tagged neutrons with 16O,nine transitions for the reaction with ^(3.)P,and nine transitions for the reaction with ^(3.)S for the first *** angular anisotropy of theγ-radiation accompanying the inelastic scattering of neutrons with an energy of 14.1 MeV on ^(3.)P nuclei was also measured for the first time.

关键词： tagged neutron method yields of gamma-quanta high-resolution gamma-spectrometry neutron-nuclear reactions neutron scattering

Preparation and Characterization of nanocomposite MgFe_2O_4/SiO_2

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Journal of Wuhan University of Technology(Materials Science) 2009年第3期24卷 354-358页

作者：徐莉 College of Science Nanjing Forestry University

nanocomposites MgFe2O4/SiO2 were successfully synthesized by the sol-gel method in the presence of n, n-dimethylformamide （DMF）. The formation of pure MgFe2O4 was confirmed by powder X-ray diffraction （XRD） and electron diffraction. The structural evolution of MgFe2O4 nanocrystals was followed by powder X-ray diffraction and IR absorption spectroscopy. The formation of spinel structure of MgFe2O4 started at 800 ℃, and completed at 900 ℃, The transmission electron microscopy （TEM） measurements suggest that the particle sizes increase with the increasing annealing temperature, and the mean particle sizes of the spherical samples annealed at 800 ℃, 900 ℃ and 1 050 ℃ are ca. 3.nm, 8 nm and 11 nm, respectively. Magnetization measurements at room temperature and 78 K indicate supemaramagnetic nature of these MgFe2O4 nanocrvstals.

关键词： nanocomposite sol-gel magnesium ferrite magnetic property

Hard life for sons in the nest?Sex-dependent offspring mortality in Great Tits in urban and forest areas

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Avian Research 2024年第1期15卷 91-97页

作者： nora Agh Henriett Anna Dalvári Krisztián Szabó Ivett Pipoly András Liker HUn-REn-PE Evolutionary Ecology Research Group University of PannoniaH-8200VeszpremPf.1158.Hungary Behavioral Ecology Research Group Center for Natural SciencesUniversity of PannoniaH-8200Pf.1158.VeszpremHungary Molecular Ecology Research Group Department of EcologyUniversity of Veterinary Medicine BudapestH-1400Pf.2.BudapestHungary Synlab Hungary Ltd. H-1211Weiss Manfr´ed Str.5-7BudapestHungary

Sex-biased mortality can occur in birds during development,for example due to sexual differences in energy requirement and/or environmental sensitivity,or the effects of sex hormones or sex differences in the expression of mutations linked to sex *** extent of sex-bias in mortality may also be related to environmental conditions that influence offspring development and *** areas often provide poorer conditions for nestling development resulting in higher offspring mortality compared to natural areas,which may accelerate sex differences in offspring mortality in *** test this hypothesis,we examined the sex ratio of dead offspring in Great Tits(Parus major),using 427 samples of unhatched eggs and dead nestlings collected in two urban and two forest sites between 2013.and *** ratio of males in the whole sample of dead offspring(56.9%)was significantly higher than expected by an 1:1 ratio,and the strongest sex biases were detected in urban areas(57.6%males)and in young nestlings(ng did not differ significantly among study sites and between offspring developmental stages.29.3.of unhatched eggs contained a visible embryo,and the proportion of embryo-containing unhatched eggs did not differ significantly between urban and forest study *** results suggest male-biased offspring mortality in Great Tits,and highlight the need of large datasets to detect subtle differences between habitats and developmental stages.

关键词： Great Tit Urbanization nestling mortality Sex related differences

Effectiveness of external prestressing in enhancing the non-ductile hanger failure mechanism in reinforced concrete inverted T-beams

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Frontiers of Structural and Civil Engineering 2024年第7期18卷 1050-1065页

作者： Ahmed M.ATTA Reda n.BEHIRY Mohammed I.HARAZ Structural Engineering Department Faculty of EngineeringTanta UniversityTanta 33511Egypt nile Higher Institute for Engineering and Technology Mansoura 11001Egypt

Recently,inverted T-beams have been used in reinforced concrete(RC)bridges to support transverse precast *** T-beams,contrary to practice with conventional beams,are loaded on the flanges upper *** loading configuration causes hanger failure due to the generation of vertical tensile stresses near the bottom of the *** key purpose of this study is to investigate the efficiency of vertical external prestressing stainless-steel bars in mitigating non-ductile hanger failure in reinforced concrete inverted *** experimental study on six inverted-T beams,including two un-strengthened specimens,was carried *** study showed that the value of the prestressing level had a considerable impact on the performance of hanger mechanism in relation to crack pattern,ultimate loads,cracking behavior,load-deflection,strains,and *** experimental results indicated that the suggested method for strengthening inverted T-beams had efficacy in reducing the seriousness of the non-ductile hanger failure and resulted in a strength increase of up to 53. when compared to that of the un-strengthened ***,two analytical models for estimating the hanger capacity and the average crack width of the strengthened RC inverted T-beams were *** models that were proposed exhibited a high degree of agreement with the experimental results.

关键词： RC bridges inverted T-beams strengthening hanger failure external prestressing

ILLUMInATIOn AnD EXPOSITIOn OF A COnVEX n-DIMEnSIOnAL BODY DEPEnDInG On ITS SHARPnESS

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Acta Mathematica Scientia 2002年第2期22卷 189-198页

作者： Boris V. Dekster Mathematics, Mount Allison University, Sackville, n.B. EOA 3.0, Canada Mt Allison Univ Sackville NB E0A 3C0 Canada

A convex n-body C is said to be exposable to a set D of a few directions if there is a linear transformation L : En → En such that L(C) arid each body isometric to L(C) is illuminated by D. Denote by En the minimum integer such that each C is exposable to a (fixed) set D of cardinality En. An upper bound for En is established here.

关键词： Covering illumination Hadwiger conjecture

In-situ study of the microstructure evolution during tension of a Mg-Y-Zn-Al alloy processed by rapidly solidified ribbon consolidation technique

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Journal of Magnesium and Alloys 2024年第5期12卷 2024-2040页

作者： Jeno Gubicza Kristián Máthis Péter nagy Péter Jenei Zoltán Hegedus Andrea Farkas Jozef Vesely Shin-ichi Inoue Daria Drozdenko Yoshihito Kawamura Department of Materials Physics Faculty of ScienceEotvos Loránd UniversityPázmány P.sétány 1/ABudapest H-1117Hungary Department of Physics of Materials Faculty of Mathematics and PhysicsCharles UniversityKe Karlovu 512116 Praha 2Czech Republic Deutsches Elektronen-Synchrotron DESY Notkestr.85Hamburg 22603Germany Magnesium Research Center Kumamoto University2-39-1 KurokamiChuo-kuKumamoto 860-8555Japan

Mg-Y-Zn-Al alloys processed by rapidly solidified ribbon consolidation(RSRC)technique exhibit an exceptional mechanical performance indicating promising application *** material has a bimodal microstructure consisting of fine recrystallized and coarse non-recrystallized grains with solute-rich stacking faults forming cluster arranged layers(CALs)and nanoplates(CAnaPs),or complete long period stacking ordered(LPSO)*** order to reveal the deformation mechanisms,in-situ synchrotron X-ray diffraction line profile analysis was employed for a detailed study of the dislocation arrangement created during tension in Mg-0.9%Zn-2.05%Y-0.15%Al(at%)*** uncovering the effect of the initial microstructure on the mechanical performance,additional samples were obtained by annealing of the as-consolidated specimen at 3.0 and 400℃ for 2 *** heat treatment at 3.0℃ had no significant effect on the initial microstructure,its evolution during tension and,thus,the overall deformation behavior under tensile *** the other hand,annealing at 400℃ resulted in a significant increase of the recrystallized grains fraction and a decrease of the dislocation density,leading to only minor degradation of the mechanical *** maximum dislocation density at the failure of the samples corresponding to the plastic strain of 10-25% was estimated to be about 16-20×10^(14)m^(-2).The diffraction profile analysis indicated that most dislocations formed during tension were of non-basal and pyramidal types,what was also in agreement with the Schmid factor values revealed independently from orientation *** was also shown that the dislocation-induced Taylor hardening was much lower below the plastic strain of 3. than above this value,which was explained by a model of the interaction between prismatic dislocations and CAnaPs/LPSO plates.

关键词： Mg-Zn-Y-Al alloy Long period stacking ordered(LPSO)phase Cluster arranged nanoplates(CAnaPs) Annealing Tension Dislocation density Hardening

Tanshinone prevents cancellous bone loss induced by ovariectomy in rats

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Acta Pharmacologica Sinica 2004年第05期25卷 136-142页

作者： Liao CUI2,3. Tie WU3. Yu-yu LIU3. Yi-feng DEnG4, Chun-mei AI4, Huai-qing CHEn22Institue of Biomedical Engineering, West China Medical Center, Sichuan University, Chengdu 610041, China 3.epartment of Pharmacology, 4Guangdong Key Laboratory for Research and Development of natural Drugs,Guangdong Medical College, Zhanjiang 524023.China Institue of Biomedical Engineering West China Medical Center Sichuan University Department of Pharmacology Guangdong Key Laboratory for Research and Development of Natural Drugs Guangdong Medical College

AIM: To investigate the skeletal effects of total tanshinone in ovariectomized rats by analyzing cancellous bonehistomorphometry of fourth lumbar vertebrae (LV4) and proximal tibial metaphyses (PTM). METHODS: Four-month-old Sprague-Dawley female rats were sham-operated and treated with vehicle or ovariectomized and treatedwith either vehicle, total tanshinone (200 mgkg-1d-1, equivalent to 3. gkg-1d-1 of tanshinone II A and 16 mgkg -1d-1 ofcryptotanshinone), or 17a-ethynylestradiol (3. gkg-1d-1 as positive treatment group) starting one day post-sur-gery for 10 weeks. Double in vivo fluorochrome labeling was administered to all rats. The undecalcified longitu-dinal LV4 and PTM sections were cut and stained with Goldners Trichrome (4-m thickness) or unstained (8-mthickness) for the bone histomorphometric analysis. RESULTS: A significant decrease in trabecular bone volume(BV/TV) and trabecular number (Tb.n) and a significant increase in osteoclast surface (OCS/BS) and mineralizingsurface (MS/BS) were found in both LV and PTM of vehicle-treated OVX rats compared with sham *** completely prevented the decreases in BV/TV and Tb.n and the increase in OCS/BS in the LV4, andpartially prevented the decreases in BV/TV and Tb.n in the PTM of OVX rats. In addition, tanshinone increasedtrabecular thickness (***) whereas it did not alter MS/BS. Moreover, tanshinone had no effect on uterine weightand body weight of OVX rats. Estrogen treatment increased BV/TV and Tb.n and decreased OCS/BS, but, alsomarkedly decreased MS/BS and increased uterine weight in OVX rats. COnCLUSIOn: The current study demon-strated that the adequate supply of tanshinone prevented OVX-induced cancellous bone loss in rats through inhibi-tion of elevated bone resorption.

关键词： tanshinone cryptotanshinone 2-fluoro-17alpha-ethynylestradiol ovariectomy bone and bones osteoclasts osteoporosis histocytochemistry morphology

Distinguishing malignant from normal stomach tissues and its in vivo, in situ measurement in operating process using FTIR Fiber-Optic techniques

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Science China Chemistry 2005年第2期48卷 167-175页

作者： XU Yizhuang1, YAnG Limin1, XU Zhi3. ZHAO Ying2, LInG Xiaofeng3. LI Qingbo1, WAnG Jiansheng4, ZHAnG nengwei3. ZHAnG Yuanfu1 & WU Jinguang1 1. The State Key Laboratory of Rare Earth Materials and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China 2. Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, China 3. Department of Surgery, Third Hospital, Peking University, Beijing 100083. China 4. Department of Oncology Surgery, the First Hospital of Xi’an Jiaotong University, Xi’an 710061, China Correspondence should be addressed to Wu Jinguang (email: wujg@***) 1. The State Key Laboratory of Rare Earth Materials and Applications College of Chemistry and Molecular Engineering Peking University 100871 Beijing China 2. Department of Surgery Third Hospital Peking University 100083 Beijing China 3. Institute of Chemistry Chinese Academy of Sciences 100080 Beijing China 4. Department of Oncology Surgery the First Hospital of Xi’an Jiaotong University 710061 Xi’an China

Gastric tissue samples were studied using mid-IR fiber-optic attenuated total reflectance (ATR) spectroscopy. FTIR spectra of 90 tissue samples from 48 patients, including 3. normal and 58 malignant tissue samples, were chosen as examples. Malignancy was usually characterized by the absence of CH and C=O bands, a weak amide II band near 1545 cm-1, a shift of the amide I band to lower wave number, a decrease in the ～1450 cm-1 peak to less than the～1400 cm-1 peak. Subtraction spectra indicate that the amide I and amide II bands of normal and malignant tissues have larger differences in peak positions and relative intensities. The statistical analysis results confirm this conclusion. The results indicate that FTIR fiber optic techniques provide important information about cancerous tissue of the stomach, which can be used to differentiate the malignant tissue from the normal tissue. Based on the above results we successfully realize the detection of the tumor tissues of digestive tract in vivo and in situ. And the results of detection cancer near operating room and in vivo and in situ in the operating room are consistent with the conclusions for the samples stored in liquid n2, which is the basis for the clinical application.

关键词： FTIR, Fiber-Optics, stomach tissues, cancer, diagnosis.