Background:Previous studies showed that New Zealand-grown ginseng contains an abundance of ginsenosides and that rare less polar ginsenosides,such as Rg3,exhibit more pharmacological activities than polar ginsenosides...Background:Previous studies showed that New Zealand-grown ginseng contains an abundance of ginsenosides and that rare less polar ginsenosides,such as Rg3,exhibit more pharmacological activities than polar ginsenosides,which are the major components of ginseng.Methods:The ginsenoside profile of New Zealand-grown Panax ginseng was manipulated by treatment with acetic acid,sodium hydroxide,pH,and high temperature.The abundance of 23 ginsenosides extracted by different treatments was quantified using high-performance liquid chromatography.Results:Treatment with 0.5 mol/L acetic acid can stimulate the degradation of polar ginsenosides to less polar ginsenosides(5.6%Rg3 was accumulated,P<0.0001).Furthermore,when ginseng root was treated at 121℃ for 100 min in a pH 3.0 acetic acid aqueous solution,the majority of the polar ginsenosides were converted into less polar ginsenosides.Specifically,83.46±3.69%(P=0.0360)of the less polar ginsenosides and 41.01±2.39%(P=0.0412)of Rg3 were enriched.In contrast,alkali treatment did not convert the polar ginsenosides into less polar ginsenosides at mild temperature and less conversion was observed compared with acid treatment at high temperature.Conclusion:This is the first attempt to manipulate the ginsenoside profile of New Zealand-grown ginseng.The conditions(high temperature with low pH)may be modified to produce and enrich the less polar ginsenoside fraction(especially Rg3)from the total ginseng extract.展开更多
This study presents new geochronological and geochemical data for Early Cretaceous volcanic rocks in the southern margin of the North China Craton(NCC),to discuss the crust–mantle interaction.The studied rocks includ...This study presents new geochronological and geochemical data for Early Cretaceous volcanic rocks in the southern margin of the North China Craton(NCC),to discuss the crust–mantle interaction.The studied rocks include pyroxene andesites from Daying Formation,hornblende andesites and andesites from Jiudian Formation,and rhyolites from a hitherto unnamed Formation.These rocks formed in Early Cretaceous(138–120 Ma),with enrichment in light rare earth elements(REE),depletion in heavy REE and arc-like trace elements characteristics.Pyroxene andesites show low SiO_(2) contents and enriched Sr–Nd–Pb–Hf isotopic compositions,with orthopyroxene phenocryst and Paleoproterozoic(2320–1829 Ma)inherited zircons,suggesting that they originated from lithospheric mantle after metasomatism with NCC lower crustal materials.Hornblende andesites have low SiO_(2) contents and high Mg#(Mg#=100 Mg/(Mg+Fe^(2+)))values,indicating a lithospheric-mantle origin.Considering the distinct wholerock Sr isotopic compositions we divide them into two groups.Among them,the low(^(87)Sr/^(86)Sr)iandesites possess amount inherited Neoarchean to Neoproterozoic(2548–845 Ma)zircons,indicating the origin of lithospheric mantle with addition of Yangtze Craton(YC)and NCC materials.In comparison,the high(^(87)Sr/^(86)Sr)iandesites,with abundant Neoarchean–Paleozoic inherited zircons(3499–261 Ma),are formed by partial melting of lithospheric mantle with incorporation of NCC supracrustal rocks and YC materials.Rhyolites have extremely high SiO_(2)(77.63–82.52 wt.%)and low total Fe_(2)O_(3),Cr,Ni contents and Mg#values,combined with ancient inherited zircon ages(2316 and 2251 Ma),suggesting an origin of NCC lower continental crust.Considering the presence of resorption texture of quartz phenocryst,we propose a petrogenetic model of’crystal mushes’for rhyolites prior to their eruption.These constraints record the intense crust–mantle interaction in the southern margin of the NCC.Given the regional data and spatial distribution of Early Cretaceous rocks within NCC,we believe that the formation of these rocks is related to the contemporaneous far-field effect of the Paleo-Pacific Plate.展开更多
We present a novel technique for controlling oxygen fugacity,which is broadly used to in-situ measure the electrical conductivities in minerals and rocks during diamond anvil cell experiments.The electrical conductivi...We present a novel technique for controlling oxygen fugacity,which is broadly used to in-situ measure the electrical conductivities in minerals and rocks during diamond anvil cell experiments.The electrical conductivities of olivine are determined under controlled oxygen fugacity conditions(Mo–MoO2)at pressures up to 4.0 GPa and temperatures up to 873 K.The advantages of this new technique enable the measuring of the activation enthalpy,activation energy,and activation bulk volume in the Arrhenius relationship.This provides an improved understanding of the mechanism of conduction in olivine.Electrical conduction in olivine is best explained by small polaron movement,given the oxygen fugacity-dependent variations in conductivity.展开更多
We present in situ trace element and Nd isotopic data of apatites from metamorphosed and metasomatized(i.e.,altered)and unaltered granitoids in the Songnen and Jiamusi massifs in the eastern Central Asian Orogenic Bel...We present in situ trace element and Nd isotopic data of apatites from metamorphosed and metasomatized(i.e.,altered)and unaltered granitoids in the Songnen and Jiamusi massifs in the eastern Central Asian Orogenic Belt,with the aim of fingerprinting granitoid petrogenesis,including both the magmatic and post-magmatic evolution processes.Apatites from altered granitoids(AG)and unaltered granitoids(UG)are characterized by distinct textures and geochemical compositions.Apatites from AG have irregular rim overgrowths and complex internal textures,along with low contents of rare earth elements(REEs),suggesting the re-precipitation of apatite during epidote crystallization and/or leaching of REEs from apatite by metasomatic fluids.eNd(t)values of the these apatites are decoupled from zircon eHf(t)values for most samples,which can be attributed to the higher mobility of Nd as compared to Sm in certain fluids.Apatites from UG are of igneous origin based on their homogeneous or concentric zoned textures and coupled Nd-Hf isotopic compositions.Trace element variations in igneous apatite are controlled primarily by the geochemical composition of the parental melt,fractional crystallization of other REEbearing minerals,and changes in partition coefficients.Sr contents and Eu/Eu^(*) values of apatites from UG correlate with whole-rock Sr and SiO2 contents,highlighting the effects of plagioclase fractionation during magma evolution.Apatites from UG can be subdivided into four groups based on REE contents.Group 1 apatites have REE patterns similar to the host granitoids,but are slightly enriched in middle REEs,reflecting the influence of the parental melt composition and REE partitioning.Group 2 apatites exhibit strong light REE depletions,whereas Group 3 apatites are depleted in middle and heavy REEs,indicative of the crystallization of epidote-group minerals and hornblende before and/or during apatite crystallization,respectively.Group 4 apatites are depleted in heavy REEs,but enriched in Sr,which are features of adakites.Some unusual geochemical features of the apatites,including the REE patterns,Sr contents,Eu anomalies,and Nd isotopic compositions,indicate that inherited apatites are likely to retain the geochemical features of their parental magmas,and thus provide a record of small-scale crustal assimilation during magma evolution that is not evident from the whole-rock geochemistry.展开更多
Both of the single crystal(SX) castability and undercoolability of PWA1383 superalloy were investigated during the directional solidifi cation and isothermal cooling. In all the six SX parts of a casting cluster, no s...Both of the single crystal(SX) castability and undercoolability of PWA1383 superalloy were investigated during the directional solidifi cation and isothermal cooling. In all the six SX parts of a casting cluster, no stray grains were found, revealing a defect-free SX structure. This excellent SX castability of the superalloy was attributed to its good undercoolability. The melting point(T_L) and the critical nucleation temperature( T_N) of the alloy were measured to be 1327 °C and 1306 °C, respectively. The statistic average of the critical nucleation undercooling Δ T_N = T_L-T_N of the alloy was determined to be about 21 K, exhibiting a relatively great capacity to be deeply cooled to a temperature below the melting point without the onset of solidifi cation.展开更多
文摘Background:Previous studies showed that New Zealand-grown ginseng contains an abundance of ginsenosides and that rare less polar ginsenosides,such as Rg3,exhibit more pharmacological activities than polar ginsenosides,which are the major components of ginseng.Methods:The ginsenoside profile of New Zealand-grown Panax ginseng was manipulated by treatment with acetic acid,sodium hydroxide,pH,and high temperature.The abundance of 23 ginsenosides extracted by different treatments was quantified using high-performance liquid chromatography.Results:Treatment with 0.5 mol/L acetic acid can stimulate the degradation of polar ginsenosides to less polar ginsenosides(5.6%Rg3 was accumulated,P<0.0001).Furthermore,when ginseng root was treated at 121℃ for 100 min in a pH 3.0 acetic acid aqueous solution,the majority of the polar ginsenosides were converted into less polar ginsenosides.Specifically,83.46±3.69%(P=0.0360)of the less polar ginsenosides and 41.01±2.39%(P=0.0412)of Rg3 were enriched.In contrast,alkali treatment did not convert the polar ginsenosides into less polar ginsenosides at mild temperature and less conversion was observed compared with acid treatment at high temperature.Conclusion:This is the first attempt to manipulate the ginsenoside profile of New Zealand-grown ginseng.The conditions(high temperature with low pH)may be modified to produce and enrich the less polar ginsenoside fraction(especially Rg3)from the total ginseng extract.
基金financially supported by the National Natural Science Foundation of China (Grant Nos. 42072063 and 41722204)Interdisciplinary Integration and Innovation Project of Jilin University (JLUXKJC2021ZZ11)Basic Scientific Research Foundation of Central Universities of China (Jilin University)。
文摘This study presents new geochronological and geochemical data for Early Cretaceous volcanic rocks in the southern margin of the North China Craton(NCC),to discuss the crust–mantle interaction.The studied rocks include pyroxene andesites from Daying Formation,hornblende andesites and andesites from Jiudian Formation,and rhyolites from a hitherto unnamed Formation.These rocks formed in Early Cretaceous(138–120 Ma),with enrichment in light rare earth elements(REE),depletion in heavy REE and arc-like trace elements characteristics.Pyroxene andesites show low SiO_(2) contents and enriched Sr–Nd–Pb–Hf isotopic compositions,with orthopyroxene phenocryst and Paleoproterozoic(2320–1829 Ma)inherited zircons,suggesting that they originated from lithospheric mantle after metasomatism with NCC lower crustal materials.Hornblende andesites have low SiO_(2) contents and high Mg#(Mg#=100 Mg/(Mg+Fe^(2+)))values,indicating a lithospheric-mantle origin.Considering the distinct wholerock Sr isotopic compositions we divide them into two groups.Among them,the low(^(87)Sr/^(86)Sr)iandesites possess amount inherited Neoarchean to Neoproterozoic(2548–845 Ma)zircons,indicating the origin of lithospheric mantle with addition of Yangtze Craton(YC)and NCC materials.In comparison,the high(^(87)Sr/^(86)Sr)iandesites,with abundant Neoarchean–Paleozoic inherited zircons(3499–261 Ma),are formed by partial melting of lithospheric mantle with incorporation of NCC supracrustal rocks and YC materials.Rhyolites have extremely high SiO_(2)(77.63–82.52 wt.%)and low total Fe_(2)O_(3),Cr,Ni contents and Mg#values,combined with ancient inherited zircon ages(2316 and 2251 Ma),suggesting an origin of NCC lower continental crust.Considering the presence of resorption texture of quartz phenocryst,we propose a petrogenetic model of’crystal mushes’for rhyolites prior to their eruption.These constraints record the intense crust–mantle interaction in the southern margin of the NCC.Given the regional data and spatial distribution of Early Cretaceous rocks within NCC,we believe that the formation of these rocks is related to the contemporaneous far-field effect of the Paleo-Pacific Plate.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11674404,41330206,and 11374121)
文摘We present a novel technique for controlling oxygen fugacity,which is broadly used to in-situ measure the electrical conductivities in minerals and rocks during diamond anvil cell experiments.The electrical conductivities of olivine are determined under controlled oxygen fugacity conditions(Mo–MoO2)at pressures up to 4.0 GPa and temperatures up to 873 K.The advantages of this new technique enable the measuring of the activation enthalpy,activation energy,and activation bulk volume in the Arrhenius relationship.This provides an improved understanding of the mechanism of conduction in olivine.Electrical conduction in olivine is best explained by small polaron movement,given the oxygen fugacity-dependent variations in conductivity.
基金supported by the National Natural Science Foundation of China(grant numbers 42072071,41772047).
文摘We present in situ trace element and Nd isotopic data of apatites from metamorphosed and metasomatized(i.e.,altered)and unaltered granitoids in the Songnen and Jiamusi massifs in the eastern Central Asian Orogenic Belt,with the aim of fingerprinting granitoid petrogenesis,including both the magmatic and post-magmatic evolution processes.Apatites from altered granitoids(AG)and unaltered granitoids(UG)are characterized by distinct textures and geochemical compositions.Apatites from AG have irregular rim overgrowths and complex internal textures,along with low contents of rare earth elements(REEs),suggesting the re-precipitation of apatite during epidote crystallization and/or leaching of REEs from apatite by metasomatic fluids.eNd(t)values of the these apatites are decoupled from zircon eHf(t)values for most samples,which can be attributed to the higher mobility of Nd as compared to Sm in certain fluids.Apatites from UG are of igneous origin based on their homogeneous or concentric zoned textures and coupled Nd-Hf isotopic compositions.Trace element variations in igneous apatite are controlled primarily by the geochemical composition of the parental melt,fractional crystallization of other REEbearing minerals,and changes in partition coefficients.Sr contents and Eu/Eu^(*) values of apatites from UG correlate with whole-rock Sr and SiO2 contents,highlighting the effects of plagioclase fractionation during magma evolution.Apatites from UG can be subdivided into four groups based on REE contents.Group 1 apatites have REE patterns similar to the host granitoids,but are slightly enriched in middle REEs,reflecting the influence of the parental melt composition and REE partitioning.Group 2 apatites exhibit strong light REE depletions,whereas Group 3 apatites are depleted in middle and heavy REEs,indicative of the crystallization of epidote-group minerals and hornblende before and/or during apatite crystallization,respectively.Group 4 apatites are depleted in heavy REEs,but enriched in Sr,which are features of adakites.Some unusual geochemical features of the apatites,including the REE patterns,Sr contents,Eu anomalies,and Nd isotopic compositions,indicate that inherited apatites are likely to retain the geochemical features of their parental magmas,and thus provide a record of small-scale crustal assimilation during magma evolution that is not evident from the whole-rock geochemistry.
基金financially supported by the Shenzhen Peacock Plan (Grant No. 20150128085205453)the Program for Guangdong Introducing Innovative and Entrepreneurial Teams (Grant No. 607264877417)+3 种基金the National Natural Science Foundation of China (Grant No. 51505457)the National Science and Technology Major Project (Grant No. 2017-Vll-0008)the Key Research and Development Program of Shaanxi Province (Grant No. 2018ZDXMGY-059)the National Science and Technology Major Project (No. 2017ZX04014001)
文摘Both of the single crystal(SX) castability and undercoolability of PWA1383 superalloy were investigated during the directional solidifi cation and isothermal cooling. In all the six SX parts of a casting cluster, no stray grains were found, revealing a defect-free SX structure. This excellent SX castability of the superalloy was attributed to its good undercoolability. The melting point(T_L) and the critical nucleation temperature( T_N) of the alloy were measured to be 1327 °C and 1306 °C, respectively. The statistic average of the critical nucleation undercooling Δ T_N = T_L-T_N of the alloy was determined to be about 21 K, exhibiting a relatively great capacity to be deeply cooled to a temperature below the melting point without the onset of solidifi cation.
