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Monomineral universal clinopyroxene and garnet barometers for peridotitic,eclogitic and basaltic systems

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Geoscience Frontiers 2017年第4期8卷 775-795页

作者： I.v.Ashchepkov T.ntaflos A.M.Logvinova Z.v.Spetsius H.Downes n.v.vladykin v.S.Sobolev Institute of Geology and Mineralogy SB RAS vienna University Alrosa Stock Company Department of Earth and Planetary Sciences Birkbeck University of London Institute of Geochemistry SD RAS

new versions of the universal Jd-Di exchange clinopyroxene barometer for peridotites,pyroxenites and eclogites,and also garnet barometer for eclogites and peridotites were *** were checked using large experimental data sets for eciogitic（~530） and peridotitic systems（〉650）.The precision of the universal Cpx barometer for peridotites based on Jd-Di exchange is close to Cr-Tschermal

关键词： Clinopyroxene Barometer Peridotite Eclogite Kimberlite Garnet

Comparison of mantle lithosphere beneath early Triassic kimberlite fields in Siberian craton reconstructed from deep-seated xenocrysts

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Geoscience Frontiers 2016年第4期7卷 639-662页

作者： I.v.Ashchepkov S.S.Kuligin n.v.vladykin H.Downes M.A.vavilov E.n.nigmatulina S.A.Babushkina n.S.Tychkov O.S.Khmelnikova lnstitute of Geology and Mineralogy SD RAS Koptyug ave 3NovosibirskRussia Institute of Geochemistry SD RAS Favorskky str laIrkutskRussia Department of Earth and Planetary Sciences Birkbeck University of LondonLondonUK Institute of Geology of Diamonds and noble metals SD RAS Lenina ave 39YakutskRussia

Mantle xenocrysts from early Triassic kimberlite pipes from Kharamai, Ary-Mastakh and Kuranakh fields in the Anabar shield of Siberia revealing similar compositional trends were studied to estimate the superplume influence on the subcratonic lithosphere mantle （SCLM）. Pressure-temperature （PT） reconstructions using monomineral thermobarometry for 5 phases show division of the SCLM beneath the Kharamai field into 6 units： pyroxenitic Fe-rich （1-2 GPa） and Mg-rich （2-3 GPa） layers; middle with two levels of Gar-Sp pyroxenites at - 3 and 4-5 GPa; Gar-dunite-harzburgites - 4.5-6.5 GPa subjected to llm-Px vein metasomatism; and a Mg-rich dunite lower part. In the Anabar shield （Ary-Mastakh, Dyuken and Kuranakh fields） mantle lithosphere is composed of three large units divided into two parts： upper part with amphiboles and phlogopite; two levels of pyroxenites and eclogites at 3 and 4 GPa, and a lower part composed of refertilized dunites. Diagrams showing P-Fe#Gar clusters for garnets and omphacites illustrate the differences between SCLM of these localities. Differences of Triassic SCLM from Devonian SCLM are in simple layering; abundance of na-Cr-amphiboles and metasomatism in the upper SCLM part, thick pyroxenite-eclogite layer and lower part depletion, heated from SCLM base to 5.0 GPa. Kharamai mantle clinopyroxenes represent three geochemical types：（1） harzburgitic with inclined linear REE, HFSE troughs and elevated Th, U; （2） lherzolitic or pyroxenitic with round TRE patterns and decreasing incompatible elements; （3） eclogitic with Eu troughs, Pb peak and high LILE content. Calculated parental melts for garnets with humped REE patterns suggest dissolution of former Cpx and depression means Cpx and garnets extraction. Clinopyroxenes from Ary-Mastakh fields show less in- dined REE patterns with HMREE troughs and an increase of incompatible elements. Clinopyroxenes from Kuranakh field show flatter spoon-like REE patterns and peaks in Ba, U, Pb and St, similar to th

关键词： Mantle lithosphere Monomineral thermobarometry Mineral geochemistry Triassic kimberlite Layering

Alakit and Daldyn kimberlite fields,Siberia,Russia:Two types of mantle sub-terranes beneath central Yakutia?

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Geoscience Frontiers 2017年第4期8卷 671-692页

作者： I.v.Ashchepkov A.M.Logvinova T.ntaflos n.v.vladykin S.I.Kostrovitsky Z.Spetsius S.I.Mityukhin S.A.Prokopyev n.S.Medvedev H.Downes Institute of Geology and Mineralogy SD RAS Institute of Geochemistry SD RAS Dept.of Lithospheric Research University of Vienna Alrosa Stock Company nikolaev Institute of Inorganic Chemistry 3 Department of Earth and Planetary Sciences Birkbeck University of London

Mineral data from Yakutian kimberlites allow reconstruction of the history of lithospheric *** occur in compositions of mantle pyropes and clinopyroxenes from large kimberlite pipes in the Alakit and Daldyn *** the Alakit ***-diopsides are alkaline,and Stykanskaya and some other pipes contain more sub-calcic pyropes and dunitic-type diamond inclusions,while in the Daldyn field harzburgitic pyropes are *** eclogitic diamond inclusions in the Alakit field are sharply divided in types and conditions,while in the Daldyn field they show varying compositions and often continuous Pressure-Temperature（P-T） ranges with increasing Fe~# with decreasing *** Alakit,Crpargasites to richterites were found in all pipes,while in Daldyn,pargasites are rare Dalnyaya and Zarnitsa ***-diopsides from the Alakit region show higher levels of light Rare Earth Elements（LREE）and stronger REE-slopes,and enrichment in light Rare Earth Elements（LREE）,sometimes Th-U,and small troughs in *** the Daldyn field,the High Field Strength Elements HFSE troughs are more common in clinopyroxenes with low REE abundances,while those from sheared and refertilized peridotites have smooth *** from Alakit show HREE minima,but those from Daldyn often have a trough at Yand high U and ***/O2 diagrams from both regions show similarities,suggesting similar layering and *** degree of metasomatism is often higher for pipes which show dispersion in P-Fe~# trends for *** the mantle beneath Udachnaya and Aykhal,pipes show 6-7 linear arrays of P-Fe~# in the lower part of the mantle section at 7.5-3.0 GPa,probably reflecting primary subduction *** the Sytykanskaya pipe,there are several horizons with opposite inclinations which reflect metasomatic *** high dispersion of the P—Fe~# trend indicating widespread metasomatism is associated with decreased diamond *** explanation of the differences in miner

关键词： Thermobarometry Geochemistry Daldyn Alakit Craton Lithosphere

The Sytykanskaya kimberlite pipe:Evidence from deep-seated xenoliths and xenocrysts for the evolution of the mantle beneath Alakit,Yakutia,Russia

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Geoscience Frontiers 2015年第5期6卷 687-714页

作者： I.v.Ashchepkov A.M.Logvinova L.F.Reimers T.ntaflos Z.v.Spetsius n.v.vladykin H.Downes D.S.Yudin A.v.Travin L.v.Makovchuk v.S.Palesskiy O.S.Khmel'nikova Institute of Geology and Mineralogy SB RAS vienna University Alrosa Stock Company Institute of Geochemistry SB RAS Birkbeck College University of LondonUKMalet Street

Mantle xenoliths（>150） and concentrates from late autolithic breccia and porphyritic kimberlite from the Sytykanskaya pipe of the Alakit field（Yakutia） were analyzed by EPMA and LAM ICP *** P-TX-f（O2） diagrams minerals from xenoliths show widest variations,the trends P-Fe#-CaO,f（O2）for minerals from porphyric kimberlites are more stepped than for xenocrysts from *** PTX points mark moving for protokimberlites from the lithosphere base（7.5 GPa） to pyroxenite lens（5-3.5 GPa） accompanied by Cr increase by AFC and creation of two trends P-Fe#OI10-12%and13-15%.The Opx-Gar-based mantle geotherm in Alakit field is close to 35 mW/m2 at 65 GPa and 600 C near Moho was *** oxidation state for the megacrystalline ilmenites is lower for the metasomatic associations due to reduction of protokimberlites on peridotites than for uncontaminated varieties at the lithosphere *** inclined linear REE patterns with deep HFSE troughs for the parental melts of clinopyroxene and garnet xenocrysts from breccia were influenced by differentiated *** for metasomatic xenoliths reveal less inclined slopes without deep troughs in spider *** reveal S-shaped REE *** clinopyroxenes from graphite bearing Cr-websterites show inclined and inflected in Gd spectrums with LREE variations due to AFC *** for garnets display less inclined patterns and Ba-Sr troughs but enrichment in ***40Ar/39Ar ages for micas from the Alakit mantle xenoliths for disseminated phlogopites reveal Proterozoic（1154 Ma） age of metasomatism in early Rodinia *** glimmerites with richterite- like amphiboles mark1015 Ma plume event in Rodinia ***600-550 Ma stage manifests final Rodinia *** last 385 Ma metasomatism is protokimberlite-related.

关键词： Kimberlites Mantle lithosphere Mantle xenoliths Th

Unveiling urbanization effects on trees outside forests along the urban-rural gradient in megacity Bengaluru

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FOREST ECOSYSTEMS 2025年第1期12卷 56-65页

作者： Jiang, Tao Freudenberg, Maximilian Kleinn, Christoph Tewari, v. P. Diwakara, B. n. noelke, nils Univ Gottingen Fac Forest Sci & Forest Ecol Forest Inventory & Remote Sensing Dept Gottingen Germany ICFRE Himalayan Forest Res Inst Shimla India IWST Inst Wood Sci & Technol Bengaluru India

Rapid urbanization has caused significant changes along the urban-rural gradient, leading to a variety of landscapes that are mainly shaped by human activities. This dynamic interplay also influences the distribution and characteristics of trees outside forests (TOF). Understanding the pattern of these trees will support informed decision-making in urban planning, in conservation strategies, and altogether in sustainable land management practices in the urban context. In this study, we employed a deep learning-based object detection model and high resolution satellite imagery to identify 1.3 million trees with bounding boxes within a 250 km2 research transect spanning the urban-rural gradient of Bengaluru, a megacity in Southern India. Additionally, we developed an allometric equation to estimate diameter at breast height (DBH) from the tree crown diameter (CD) derived from the detected bounding boxes. Our study focused on analyzing variations in tree density and tree size along this gradient. The findings revealed distinct patterns: the urban domain displayed larger tree crown diameters (mean: 8.87 m) and DBH (mean: 43.78 cm) but having relatively low tree density (32 trees per hectare). Furthermore, with increasing distance from the city center, tree density increased, while the mean tree crown diameter and mean tree basal area decreased, showing clear differences of tree density and size between the urban and rural domains in Bengaluru. This study offers an efficient methodology that helps generating instructive insights into the dynamics of TOF along the urban-rural gradient. This may inform urban planning and management strategies for enhancing green infrastructure and biodiversity conservation in rapidly urbanizing cities like Bengaluru.

关键词： Individual tree detection Urbanization Tree density Tree crown diameter

Unveiling urbanization effects on trees outside forests along the urban-rural gradient in megacity Bengaluru

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Forest Ecosystems 2025年第01期 56-65页

作者： Tao Jiang Maximilian Freudenberg Christoph Kleinn v.P.Tewari B.n.Diwakara nils n?lke Forest Inventory and Remote Sensing Department Faculty of Forest Sciences and Forest Ecology University of G?ttingen Himalayan Forest Research Institute ICFRE Institute of Wood Science and Technology IWST

Rapid urbanization has caused significant changes along the urban-rural gradient, leading to a variety of landscapes that are mainly shaped by human activities. This dynamic interplay also influences the distribution and characteristics of trees outside forests(TOF). Understanding the pattern of these trees will support informed decision-making in urban planning, in conservation strategies, and altogether in sustainable land management practices in the urban context. In this study, we employed a deep learning-based object detection model and high resolution satellite imagery to identify 1.3 million trees with bounding boxes within a 250 km2research transect spanning the urban-rural gradient of Bengaluru, a megacity in Southern India. Additionally, we developed an allometric equation to estimate diameter at breast height(DBH) from the tree crown diameter(CD) derived from the detected bounding boxes. Our study focused on analyzing variations in tree density and tree size along this gradient. The findings revealed distinct patterns: the urban domain displayed larger tree crown diameters(mean:8.87 m) and DBH(mean: 43.78 cm) but having relatively low tree density(32 trees per hectare). Furthermore,with increasing distance from the city center, tree density increased, while the mean tree crown diameter and mean tree basal area decreased, showing clear differences of tree density and size between the urban and rural domains in Bengaluru. This study offers an efficient methodology that helps generating instructive insights into the dynamics of TOF along the urban-rural gradient. This may inform urban planning and management strategies for enhancing green infrastructure and biodiversity conservation in rapidly urbanizing cities like Bengaluru.

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Dendritic spine degeneration:a primary mechanism in the aging process

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neural Regeneration Research 2025年第6期20卷 1696-1698页

作者： Gonzalo Flores Leonardo Aguilar-Hernández Fernado García-Dolores Humberto nicolini Andrea Judith vázquez-Hernández Hiram Tendilla-Beltrán Instituto de Fisiología Benemérita Universidad Autónoma de Puebla(BUAP)PueblaMexico Instituto de Ciencias Forenses(InCIFO) Tribunal Superior de Justicia de la Ciudad de México(TSJCDMX).Mexico CityMexico Instituto nacional de Medicina Genómica(InMEGEn) Mexico CityMexico

Recent reports suggest that aging is not solely a physiological process in living beings;instead, it should be considered a pathological process or disease(Amorim et al., 2022). Consequently, this process involves a wide range of factors, spanning from genetic to environmental factors, and even includes the gut microbiome(GM)(Mayer et al., 2022). All these processes coincide at some point in the inflammatory process, oxidative stress, and apoptosis, at different degrees in various organs and systems that constitute a living organism(Mayer et al., 2022;AguilarHernández et al., 2023).

关键词： aging process stress

La3+ substitution-adjusted magnetic and optical properties with enhanced photocatalytic activity and stability of copper zinc nickel ferrites for wastewater treatment applications

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Journal of Rare Earths 2025年第2期43卷 319-328页

作者： n.S.Al-Bassami General Studies Department Jubail Industrial College

Copper-zinc-nickel（Cu-Zn-ni） ferrite nanoparticles are used for wastewater treatment ***,low degradation efficiency and stability are two main issues that make them unsuitable for actual production *** this paper,the citrate-nitrate auto-combustion method was applied for the formation of Cu0.5Zn0.25ni0.25LaxFe2-xO4;（0≤x≤0.1;step 0.02）(CZnL) *** the substitution process entails the replacement of a small ion with a larger one,the lattice constant and crystallite size does not exhibit a consistent incremental *** behavior is justified and *** size of all the CZnL ferrite nanoparticles is in the range of 8-12 nm,and the lattice constant is in the range of 8.6230 to 8.4865 *** morphological analysis conducted using field emission-scanning electron microscopy（FE-SEM） reveals that the CZnL exhibits agglomerated spherical *** energy dispersive X-ray spectrameter（EDAX） analysis was employed to confirm the elemental composition of CZnL *** the process entails the substitution of Fe3+magnetic ions with nonmagnetic ions La3+,the magnetic parameters of CZnL nanoferrites show a general decreasing trend as *** 20 K,saturation magnetization Ms shows an overall drop in its values from 59.302 emu/g at x=0.0-41.295 emu/g at x=0.1,the smallest value of 37.87 emu/g is recorded at x=*** highest coercivity（Hc=125.9 Oe） and remanence（Mr=13.32 emu/g） are recorded for x=0.08 and x=0.04 nanoferrite,*** band gap of all the CZnL nanoferrites was determined using the Kubelka-Munk function and Tauc plot for direct permitted *** doping modifies the band gap（within 1.86-1.75 ev）,increases light absorption,induces efficient e/h separation and charge migration to *** nanoferrite Cu0.5Zn0.25ni0.25La0.06Fe1.94O4achieves a degradation efficiency of 97.3% for methylene blue（MB） dye removal after just 60 *** five recycling processes,the nanoc

关键词： Copper-zinc-nickel Ferrite Photocatalytic properties Rare earths Wastewater treatment

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块系岩体准共振诱发弱夹层拉压损伤断裂研究

岩石力学与工程学报 2025年第1期44卷 114-127页

作者：王凯兴徐伟刚潘一山薛佳琪 OPARIn v n KIRYAEvA T A 辽宁工程技术大学力学与工程学院辽宁阜新123000 俄罗斯科学院西伯利亚分院矿业研究所俄罗斯新西伯利亚630091

当外界扰动频率接近块系岩体的固有频率时,会出现准共振现象。这一现象导致岩块间的弱夹层应变急剧变化,从而加快弱夹层的动态损伤断裂。为了研究块系岩体准共振导致岩块间弱夹层的动态拉压损伤断裂规律,基于块系岩体模型,分析准共振状... 详细信息

当外界扰动频率接近块系岩体的固有频率时,会出现准共振现象。这一现象导致岩块间的弱夹层应变急剧变化,从而加快弱夹层的动态损伤断裂。为了研究块系岩体准共振导致岩块间弱夹层的动态拉压损伤断裂规律,基于块系岩体模型,分析准共振状态下弱夹层的变形特征。结合岩石动态损伤断裂准则,对准共振状态下弱夹层的动态损伤断裂进行理论计算分析,进而研究动态破坏规律。通过数值模拟揭示了准共振状态下块系岩体中弱夹层的损伤演化特征。结果表明:当块系岩体发生准共振现象时,岩块间的相对位移急剧增加,使得弱夹层的应变和损伤程度明显增大;弱夹层的损伤程度在准共振频率下最高,同时受外部扰动力和弱夹层的刚度、黏性、厚度及岩块质量等系统参数的影响;块系岩体发生准共振时断裂应力增大,但从断裂到完全破坏的时间明显缩短,即残余承载能力大幅下降。该研究对认识块系岩体的动态断裂具有一定的参考价值。

关键词：岩石力学块系岩体准共振弱夹层变形动态损伤断裂