The Wugong Mts. region may have experienced three stages of metamorphism in Early Paleo-zoic, which may be closely related to the generations of regional deformation. The first stage ismedium-pressure metamorphism, th...The Wugong Mts. region may have experienced three stages of metamorphism in Early Paleo-zoic, which may be closely related to the generations of regional deformation. The first stage ismedium-pressure metamorphism, the second medium- and high-pressure one with stress on high-pressure metamorphism, and the third low-pressure and high-temperature metamorphism. Theregion, as a whole, is a Caledonian medium-high pressure metamorphic belt.展开更多
Silicate glass-ceramics were prepared by adding 40 wt%granite wastes.The effects of CaO/MgO(C/M)molar ratio on microstructure and mechanical properties of glass-ceramics were investigated.With C/M ratio increasing,the...Silicate glass-ceramics were prepared by adding 40 wt%granite wastes.The effects of CaO/MgO(C/M)molar ratio on microstructure and mechanical properties of glass-ceramics were investigated.With C/M ratio increasing,the crystallization behavior changed from bulk crystallization to surface crystallization with heat treatment at 800℃.However,bulk crystallization occurred in all samples when crystallized at both 850 and 900℃.The content of forsterite and tainiolite initially increased and then decreased,while diopside and kalsilite increased when heated at 850℃.For 900℃,the increase of C/M ratio promoted the precipitation of diopside rather than forsterite and tainiolite,and interlocked plate crystals abundantly appeared with C/M ratio≥0.14.The values of Vickers hardness for samples crystallized at 850 and 900℃increased initially followed by a decrease,while the values of fracture toughness showed the opposite trend.The glass-ceramic with C/M ratio 0.065 heated at 900℃showed relatively high Vickers hardness((5.7±0.14)GPa)and excellent fracture toughness((3.55±0.14)MPa·m^(1/2)).展开更多
The middle-scale Heima zinnwaldite deposit is situated in the southeastern Tibetan Plateau,SW China.The NNW-to NS-trending orebodies are hosted in the Gaoligongshan metamorphic zone.To clarify the zinnwaldite genesis ...The middle-scale Heima zinnwaldite deposit is situated in the southeastern Tibetan Plateau,SW China.The NNW-to NS-trending orebodies are hosted in the Gaoligongshan metamorphic zone.To clarify the zinnwaldite genesis at Heima,this study presents an integrated investigation of the Heima pegmatites,combining precise geochronology,isotopic tracing,and detailed mineral chemistry to constrain its formation age,petrogenetic origin,and mineralization processes.Our robust geochronological framework,employing magmatic zircon(56.93±0.53 Ma)and cassiterite(57.0±4.2 Ma),establishes the pegmatite emplacement during the Late Paleocene to Early Eocene,representing the maximum age of lithium mineralization.Hf isotopic compositions(εHf_((t))=−14.3 to−12.4)demonstrate that the Heima pegmatite originated from remelting of ancient sediments,distinguishing it from contemporaneous Eocene Gangdese-Tengchong granites(εHf_((t))=−12.7 to+11.0)that show mantle contributions.This crustal signature aligns with the evolutionary trend of Hf isotopes in regional gneissic granites(600−420 Ma),supporting an anatectic origin from ancient continental crust rather than being derivatives of nearby Eocene granitic plutons.Detailed geochemical analysis of Li-micas reveals two distinct generations with contrasting formation mechanisms.The primary mica-Ia(53.45±0.86 Ma,Rb-Sr age)exhibits extreme incompatible element enrichment(Li,Be,Rb,Cs)and remarkably low K/Rb ratios(3.98-4.37),characteristic of crystallization from highly fractionated granitic melts.In contrast,secondary mica-Ib and mica-Ⅱ(17.9-16.0 Ma,Rb-Sr age)show significant Nb-Ta-W enrichment,reflecting precipitation from F-P-rich hydrothermal fluids during Miocene metamorphic-hydrothermal events.Principal component analysis(PCA)confirms the compositional disparity between these mica generations,with the later phases attributed to fluid-induced alteration and reworking.Regional correlation identifies two distinct lithium mineralization episodes in the Gongshan area,southeast Tibetan Plateau.The Eocene phase(~55 Ma)is zinnwaldite-dominant(e.g.,Heima,Puladi),associated with crustal melting following Neo-Tethyan closure.The Miocene phase(~17 Ma)is spodumene-dominant(e.g.,Danzhu,Peili),linked to Himalayan leucogranites formed as the rapid exhumation,denudation,and decompression partial melting of Himalayan Crystalline Complex.展开更多
The surface of MoSi2-SiB6/phenolic resin matrix composites was modified by mica,and the thermal oxidation behavior of the composites and the mechanical properties of the pyrolysis products were studied.The results sho...The surface of MoSi2-SiB6/phenolic resin matrix composites was modified by mica,and the thermal oxidation behavior of the composites and the mechanical properties of the pyrolysis products were studied.The results showed that the mica improved the thermal properties of the composites,the thermal expansion coefficient decreased,and the liquid phase formation caused the composites to shrink and increase the density.The flexural strength of mica surface modified composites not only increased to 78.64MPa after thermal treatment at 800-1200℃,but reached 83.02 MPa after high temperature treatment at1400℃.The improvement of the mechanical properties of the residual product benefits from the formation of high temperature ceramic phases such as Mo_(2)C and MoB,and the improvement of the shear strength of the composites by the mica.The shear strength of MBm5-2 at room temperature reached 33.08 MPa,indicating that the improvement of the interlayer properties of the composites further improved its mechanical properties.展开更多
目的观察乳腺肿瘤细胞膜MHCⅠ链相关分子A(MHC class I chain-related gene A,MICA)及血清中可溶性MICA表达,探讨MICA在NK细胞杀伤乳腺癌中的作用。方法流式细胞术检测膜型MICA(mMICA)及NK细胞表面NKG2D表达,观察膜型MICA、可溶性MICA(s...目的观察乳腺肿瘤细胞膜MHCⅠ链相关分子A(MHC class I chain-related gene A,MICA)及血清中可溶性MICA表达,探讨MICA在NK细胞杀伤乳腺癌中的作用。方法流式细胞术检测膜型MICA(mMICA)及NK细胞表面NKG2D表达,观察膜型MICA、可溶性MICA(sMICA)对NKG2D表达的影响;免疫组织化学检测膜型MICA及可溶性MICA的表达及分布;抗体封闭法观察膜型MICA与NKG2D相互作用。结果乳腺细胞膜型MICA在正常组织不表达,在良性肿瘤表达量为(38.5±7.5)%,恶性肿瘤表达量为(53.2±5.6)%。可溶性MICA含量在健康成年人为阴性,在乳腺良性肿瘤患者血清中含量(76.8±22.3)pg/mL,在恶性肿瘤患者中含量(205.36±71.27)pg/mL。经NKG2D或MICA抗体封闭后,NK细胞的杀瘤活性显著减弱。含可溶性MICA的血清可明显下调NKG2D的表达。结论大部分乳腺肿瘤细胞膜都有MICA的表达,可作为乳腺肿瘤相关性抗原。膜型MICA与NKG2D的相互识别在介导NK细胞抗乳腺癌中起重要作用,而可溶性MICA通过下调NKG2D表达介导肿瘤免疫逃逸。展开更多
文摘The Wugong Mts. region may have experienced three stages of metamorphism in Early Paleo-zoic, which may be closely related to the generations of regional deformation. The first stage ismedium-pressure metamorphism, the second medium- and high-pressure one with stress on high-pressure metamorphism, and the third low-pressure and high-temperature metamorphism. Theregion, as a whole, is a Caledonian medium-high pressure metamorphic belt.
基金National Natural Science Foundation of China(Nos.52172019,51804131)Shandong Provincial Youth Innovation Team Development Plan of Colleges and Universities(No.2022KJ100)。
文摘Silicate glass-ceramics were prepared by adding 40 wt%granite wastes.The effects of CaO/MgO(C/M)molar ratio on microstructure and mechanical properties of glass-ceramics were investigated.With C/M ratio increasing,the crystallization behavior changed from bulk crystallization to surface crystallization with heat treatment at 800℃.However,bulk crystallization occurred in all samples when crystallized at both 850 and 900℃.The content of forsterite and tainiolite initially increased and then decreased,while diopside and kalsilite increased when heated at 850℃.For 900℃,the increase of C/M ratio promoted the precipitation of diopside rather than forsterite and tainiolite,and interlocked plate crystals abundantly appeared with C/M ratio≥0.14.The values of Vickers hardness for samples crystallized at 850 and 900℃increased initially followed by a decrease,while the values of fracture toughness showed the opposite trend.The glass-ceramic with C/M ratio 0.065 heated at 900℃showed relatively high Vickers hardness((5.7±0.14)GPa)and excellent fracture toughness((3.55±0.14)MPa·m^(1/2)).
基金supported by the Ministry of Natural Resources-Provincial Joint Cooperation Project in 2024(No.2024ZRBSHZ126)The Second Comprehensive Scientific Research Project on the Qinghai-Tibetan Plateau“Assessment of Current Status and Future Prospects for Rare Metal Resources”(No.2019QZKK0802)+4 种基金Yunnan Foundation Project(No.202201AU070162)Career Development Fund for Early-Career Geologists at YIGS(No.YDKYR[2024]3)YDIG Expert Innovation Studio(No.YDIG[2024]24)New round of Yunnan Province prospecting Action and Project of Geological Exploration Fund(No.K202408)KUST-NSRF Talent Development Project(No.KKZ3202421133).
文摘The middle-scale Heima zinnwaldite deposit is situated in the southeastern Tibetan Plateau,SW China.The NNW-to NS-trending orebodies are hosted in the Gaoligongshan metamorphic zone.To clarify the zinnwaldite genesis at Heima,this study presents an integrated investigation of the Heima pegmatites,combining precise geochronology,isotopic tracing,and detailed mineral chemistry to constrain its formation age,petrogenetic origin,and mineralization processes.Our robust geochronological framework,employing magmatic zircon(56.93±0.53 Ma)and cassiterite(57.0±4.2 Ma),establishes the pegmatite emplacement during the Late Paleocene to Early Eocene,representing the maximum age of lithium mineralization.Hf isotopic compositions(εHf_((t))=−14.3 to−12.4)demonstrate that the Heima pegmatite originated from remelting of ancient sediments,distinguishing it from contemporaneous Eocene Gangdese-Tengchong granites(εHf_((t))=−12.7 to+11.0)that show mantle contributions.This crustal signature aligns with the evolutionary trend of Hf isotopes in regional gneissic granites(600−420 Ma),supporting an anatectic origin from ancient continental crust rather than being derivatives of nearby Eocene granitic plutons.Detailed geochemical analysis of Li-micas reveals two distinct generations with contrasting formation mechanisms.The primary mica-Ia(53.45±0.86 Ma,Rb-Sr age)exhibits extreme incompatible element enrichment(Li,Be,Rb,Cs)and remarkably low K/Rb ratios(3.98-4.37),characteristic of crystallization from highly fractionated granitic melts.In contrast,secondary mica-Ib and mica-Ⅱ(17.9-16.0 Ma,Rb-Sr age)show significant Nb-Ta-W enrichment,reflecting precipitation from F-P-rich hydrothermal fluids during Miocene metamorphic-hydrothermal events.Principal component analysis(PCA)confirms the compositional disparity between these mica generations,with the later phases attributed to fluid-induced alteration and reworking.Regional correlation identifies two distinct lithium mineralization episodes in the Gongshan area,southeast Tibetan Plateau.The Eocene phase(~55 Ma)is zinnwaldite-dominant(e.g.,Heima,Puladi),associated with crustal melting following Neo-Tethyan closure.The Miocene phase(~17 Ma)is spodumene-dominant(e.g.,Danzhu,Peili),linked to Himalayan leucogranites formed as the rapid exhumation,denudation,and decompression partial melting of Himalayan Crystalline Complex.
基金Funded by the National Natural Science Foundation of China(Nos.52171045,52162013,and 51932006)。
文摘The surface of MoSi2-SiB6/phenolic resin matrix composites was modified by mica,and the thermal oxidation behavior of the composites and the mechanical properties of the pyrolysis products were studied.The results showed that the mica improved the thermal properties of the composites,the thermal expansion coefficient decreased,and the liquid phase formation caused the composites to shrink and increase the density.The flexural strength of mica surface modified composites not only increased to 78.64MPa after thermal treatment at 800-1200℃,but reached 83.02 MPa after high temperature treatment at1400℃.The improvement of the mechanical properties of the residual product benefits from the formation of high temperature ceramic phases such as Mo_(2)C and MoB,and the improvement of the shear strength of the composites by the mica.The shear strength of MBm5-2 at room temperature reached 33.08 MPa,indicating that the improvement of the interlayer properties of the composites further improved its mechanical properties.
文摘目的观察乳腺肿瘤细胞膜MHCⅠ链相关分子A(MHC class I chain-related gene A,MICA)及血清中可溶性MICA表达,探讨MICA在NK细胞杀伤乳腺癌中的作用。方法流式细胞术检测膜型MICA(mMICA)及NK细胞表面NKG2D表达,观察膜型MICA、可溶性MICA(sMICA)对NKG2D表达的影响;免疫组织化学检测膜型MICA及可溶性MICA的表达及分布;抗体封闭法观察膜型MICA与NKG2D相互作用。结果乳腺细胞膜型MICA在正常组织不表达,在良性肿瘤表达量为(38.5±7.5)%,恶性肿瘤表达量为(53.2±5.6)%。可溶性MICA含量在健康成年人为阴性,在乳腺良性肿瘤患者血清中含量(76.8±22.3)pg/mL,在恶性肿瘤患者中含量(205.36±71.27)pg/mL。经NKG2D或MICA抗体封闭后,NK细胞的杀瘤活性显著减弱。含可溶性MICA的血清可明显下调NKG2D的表达。结论大部分乳腺肿瘤细胞膜都有MICA的表达,可作为乳腺肿瘤相关性抗原。膜型MICA与NKG2D的相互识别在介导NK细胞抗乳腺癌中起重要作用,而可溶性MICA通过下调NKG2D表达介导肿瘤免疫逃逸。
