The sense of mammalian hearing exhibits nonlinear phenomena which are most significant to hearing function, such as nonlinear dynamic compression, nonlinear tuning and combination tones. These nonlinear phenomena are ...The sense of mammalian hearing exhibits nonlinear phenomena which are most significant to hearing function, such as nonlinear dynamic compression, nonlinear tuning and combination tones. These nonlinear phenomena are suggested to originate from the Hopf amplification within the cochlea, while the mechanism underlying the Hopf amplification remains elusive. According to the experimental results of force-gating channel operation in hair cells, through a theoretic model, this work reveals a velocity-dependent open probability of force-gating channels in auditory hair cells, and a velocity-dependent active force produced by the force-gating channel operating, which makes sensors hear typical Hopf vibrators with nonlinear hearing phenomena.展开更多
Nanyang shadow puppetry has a long history.It originated in the Han Dynasty and grew from folk rap art,combining various art forms like painting,sculpture(雕塑),and opera.In the past,rural cultural life in Nanyang was...Nanyang shadow puppetry has a long history.It originated in the Han Dynasty and grew from folk rap art,combining various art forms like painting,sculpture(雕塑),and opera.In the past,rural cultural life in Nanyang was rare;shadow puppetry was a key form of entertainment(娱乐).During festivals,temple fairs,or slack farming seasons,troupes would visit villages to give wonderful shows.展开更多
The different reservoirs in deep Songliao Basin have non-homogeneous lithologies and include multiple layers with a high content of hydrogen gas.The gas composition and stable isotope characteristics vary significantl...The different reservoirs in deep Songliao Basin have non-homogeneous lithologies and include multiple layers with a high content of hydrogen gas.The gas composition and stable isotope characteristics vary significantly,but the origin analysis of different gas types has previously been weak.Based on the geochemical parameters of gas samples from different depths and the analysis of geological settings,this research covers the diverse origins of natural gas in different strata.The gas components are mainly methane with a small amount of C_(2+),and non-hydrocarbon gases,including nitrogen(N_(2)),hydrogen(H_(2)),carbon dioxide(CO_(2)),and helium(He).At greater depth,the carbon isotope of methane becomes heavier,and the hydrogen isotope points to a lacustrine sedimentary environment.With increasing depth,the origins of N_(2)and CO_(2)change gradually from a mixture of organic and inorganic to inorganic.The origins of hydrogen gas are complex and include organic sources,water radiolysis,water-rock(Fe^(2+)-containing minerals)reactions,and mantle-derived.The shales of Denglouku and Shahezi Formations,as source rocks,provide the premise for generation and occurrence of organic gas.Furthermore,the deep faults and fluid activities in Basement Formation control the generation and migration of mantle-derived gas.The discovery of a high content of H_(2)in study area not only reveals the organic and inorganic association of natural-gas generation,but also provides a scientific basis for the exploration of deep hydrogen-rich gas.展开更多
Aging in oak barrels is widely used in enology which could bring flavor changes and aromatic complexity to wines.In the present study,the aroma compounds were analyzed from the‘Merlot’dry red wines,which were fermen...Aging in oak barrels is widely used in enology which could bring flavor changes and aromatic complexity to wines.In the present study,the aroma compounds were analyzed from the‘Merlot’dry red wines,which were fermented in two types of fermenters(stainless steel tank and rotated oak barrel)and aged in six types of oak barrels(three geographic origins×two toasting degrees)for different time(0,3,6 and 9 months,respectively).Results showed that 30 volatiles were associated with barrels and increased during oak aging.The fermenters could influence the intensities of the toast,leathery,smoky,fruity,floral and caramel aromas.The concentration of whisky lactone,eugenol,cis-isoeugenol,and the intensities of the toast and spicy aromas were highest in the wines aged in American oak and were lowest in the wines aged in French oak barrels.The concentrations of guaiacol,syringol,trans-isoeugenol,furfural alcohol,vanilla,cis-whisky lactone enabled the medium toasting barrels to be distinguished from the light toasting ones.The compounds originating from the barrels could be used to distinguish the types of different barrels,but the other general grape-derived and fermentation-derived volatiles could not.The fermenters,oak species and toasting degrees of the barrels all had significant effects on the aroma profiles of the aged‘Merlot’dry red wines,but the influence of the geographic origin was not obvious.展开更多
A total of 45 alkylbenzenes were detected and identified in crude oils with different depositional environments and thermal maturities from the Tarim Basin,Beibuwan Basin,and Songliao Basin using comprehensive two-dim...A total of 45 alkylbenzenes were detected and identified in crude oils with different depositional environments and thermal maturities from the Tarim Basin,Beibuwan Basin,and Songliao Basin using comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry(GC×GCTOFMS).By analyzing the distribution characteristics of C0-C5alkylbenzenes,it is found that the content of some alkylbenzenes varies greatly in crude oils.Based on the distribution characteristics of 1,2,4,5-tetramethylbenzene(Te MB)and 1,2,3,4-Te MB,the ratio of 1,2,4,5-Te MB to 1,2,3,4-Te MB is proposed to indicate the organic matter origin and depositional environment of ancient sediments.Oil samples originated mainly from lower hydrobiont,algae,bacteria and source rocks deposited under reducing/anoxic conditions have low 1,2,4,5-/1,2,3,4-Te MB values(less than 0.6),while oil samples originated mainly from terrestrial higher plants and source rocks deposited under oxic/sub-oxic conditions have higher 1,2,4,5-/1,2,3,4-Te MB values(greater than 1.0).The significant difference of 1,2,4,5-/1,2,3,4-Te MB values is controlled by 1,2,4,5-Te MB content.1,2,4,5-Te MB content in oils derived from source rocks deposited in oxidized sedimentary environment(greater than 1.0 mg/g whole oil)is higher than that in oils from source rocks deposited in reduced sedimentary environment(less than 1.0 mg/g whole oil).1,2,4,5-/1,2,3,4-Te MB ratio might not or slightly be affected by evaporative fractionation,biodegradation and thermal maturity.1,2,4,5-/1,2,3,4-Te MB ratio and 1,2,4,5-Te MB content can be used as supplementary parameter for the identification of sedimentary environment and organic matter input.It should be noted that compared to the identification of organic matter sources,the 1,2,4,5-/1,2,3,4-Te MB parameter is more effective in identifying sedimentary environments.展开更多
Based on the analysis of light hydrocarbon compositions of natural gas and regional comparison in combination with the chemical components and carbon isotopic compositions of methane,the indication of geochemical char...Based on the analysis of light hydrocarbon compositions of natural gas and regional comparison in combination with the chemical components and carbon isotopic compositions of methane,the indication of geochemical characteristics of light hydrocarbons on the migration features,dissolution and escape of natural gas from the Dongsheng gas field in the Ordos Basin is revealed,and the effect of migration on specific light hydrocarbon indexes is further discussed.The study indicates that,natural gas from the Lower Shihezi Formation(Pix)in the Dongsheng gas field displays higher iso-C5-7contents than n-C5-7contents,and the C6-7light hydrocarbons are composed of paraffins with extremely low aromatic contents(<0.4%),whereas the C7light hydrocarbons are dominated by methylcyclohexane,suggesting the characteristics of coal-derived gas with the influence by secondary alterations such as dissolution.The natural gas from the Dongsheng gas field has experienced free-phase migration from south to north and different degrees of dissolution after charging,and the gas in the Shiguhao area to the north of the Borjianghaizi fault has experienced apparent diffusion loss after accumulation.Long-distance migration in free phase results in the decrease of the relative contents of the methylcyclohexane in C7 light hydrocarbons and the toluene/n-heptane ratio,as well as the increase of the n-heptane/methylcyclohexane ratio and heptane values.The dissolution causes the increase of isoheptane values of the light hydrocarbons,whereas the diffusion loss of natural gas in the Shiguhao area results in the increase of n-C5-7contents compared to the iso-C5-7contents.展开更多
Turquoise, a hydrous phosphate of copper and aluminum, is highly valued for its unique colour and historical significance. The similarity in colour, quality, and pattern between turquoises from different localities ma...Turquoise, a hydrous phosphate of copper and aluminum, is highly valued for its unique colour and historical significance. The similarity in colour, quality, and pattern between turquoises from different localities may lead to confusion in determining their origins. This is particularly evident in the case of turquoises from Meiduk in Iran and Tongling in China(Fig.1).In Iran, turquoise deposits are typically associated with magmatic zones, specifically in the Meiduk mine, located 85 kilometers northwest of the Sar Cheshmeh porphyry copper deposit in Kerman Province. The deposit is hosted by Eocene volcanic rocks of andesitic-basaltic composition with porphyry-type mineralization associated with two Miocene calc-alkaline intrusive phases. Five distinct zones of the hypogene alteration include potassic, potassic-phyllic, phyllic, and propylitic zones, which are rich in magnetite. Mineralization processes include stockwork, dissemination, veinlets, and veins rich in garnet, chalcopyrite, magnetite, and anhydrite. Turquoise is found in transitional, leached, and supergene zones, primarily as fracture and seam fillers. In contrast, Chinese turquoises are more often found in sedimentary rocks, with significant exceptions in places like the Tongling mine in Anhui Province, which are hosted within magmatic rocks. The turquoise from Tongling is found in the Tongling area within the Middle-lower Yangtze Metallogenic Belt, an area characterized by complex tectonics and intense magmatic and metallogenic activities. The turquoise deposits are associated with iron-copper polymetallic mineralization within Early Cretaceous volcanic rocks.The turquoise from Meiduk exhibited a specific gravity range of 2.22 g/cm^(3)to 2.71 g/cm^(3), SWUV fluorescence from none to medium, and LWUV fluorescence from faint to strong, indicating diverse mineralogical compositions. SEM examination of turquoise from Meiduk reveals a variety of mineral morphologies. The turquoise displays closely packed arrays of elongated needle-like crystals, measuring 2 μm to 9 μm in length and 0.1 μm to 0.4 μm in thickness, indicating a dynamic growth environment. The density and alignment of these crystals suggest the space-constrained setting, likely influenced by rapid deposition from mineral-laden fluids, with crystals interlocked due to simultaneous nucleation events. Some crystals appear similarly elongated but are more dispersed, with greater separation between individual crystals. In other areas, the elongated turquoise crystals are tightly intergrown, creating a dense textural appearance, pointing to a stage where growth space became limited, resulting in an interlocking matrix. Additionally, some crystals radiate outward from a central point, forming a spherical pattern reaching about 18 μm. The turquoise from Tongling show a specific gravity range of 2.26 g/cm^(3)to 2.60 g/cm^(3), with consistent medium SWUV fluorescence and strong LWUV fluorescence. SEM examination reveals needle structures, plate-like structures, and spheroidal aggregates composed of needle and plate-like microcrystals. These spherical aggregates, some with diameters around 26 μm, exhibit the concentric growth structure covered by turquoise microcrystals, with crystal lengths of 8 μm. The surface needle-like microcrystals vary in size, approximately 3 μm in length, 2 μm in width, and 0.2 to 0.6 μm in thickness.Optical microscopy, Raman and FTIR spectroscopy reported the presence of quartz, gypsum, iron oxides such as jarosite and goethite, biotite, sericite, pyrite, galena, bornite, graphene oxide, malachite, and azurite as major associated minerals of Meiduk's. In contrast, the Tongling mine features minerals such as quartz, anatase, barite, sodium feldspar, illite, and malachite.Through EPMA and LA-ICP-MS results, the turquoises of Tongling exhibit similar average iron content(1.28% and 1.26% respectively), but significant differences in copper content. The turquoises of Meiduk have the average copper content of 6.97%, whereas Tongling samples show the higher content of 11.38%. Na, K, and Ca concentrations are also higher in Meiduk samples, suggesting interaction with alkali-rich fluids and potassic alteration. Trace elements such as Ti, Cr, Zn, Se, and Mo serve as tracing agents for Meiduk samples, while Be and W are associated with Tongling samples. Regarding rare earth elements(REEs), Meiduk samples show diverse δCe(0.14-4.62) and δEu(0.65-15.78) values, indicating a wide range of oxidation states and europium anomalies. The significant variability in LREE/HREE ratios(0.39-31.74) and ΣREE concentrations(0.25-240.72 ppm) suggests heterogeneous REE fractionation patterns. In contrast, Tongling samples display δCe(0.070-2.51) and δEu(0.238-4.87) ranges, with more consistent LREE/HREE ratios(0.128-10.2) and ΣREE values(0.069-4.08 ppm), indicating stable REE fractionation dynamics.This comparative study of turquoises from the Meiduk mine in Iran and the Tongling mine in China reveals significant similarities and differences in their geochemical and mineralogical characteristics. Both deposits are hosted within magmatic rocks and produce turquoise as a byproduct in open-pit copper mining operations, exhibiting comparable colors, patterns, and morphologies. However, distinct differences are noted in their mineral compositions and trace elements, with turquoise from Meiduk associated with a complex hydrothermal system rich in various sulfide and oxide minerals and higher copper, Na, K, and Ca concentrations, indicating alkali-rich fluid interactions. In contrast, the turquoise from Tongling, influenced by both volcanic and sedimentary processes, shows a higher copper content, presence of barite, and different trace elements such as Be and W. The REE patterns also highlight the contrasting geological histories and environmental conditions at each site, with Meiduk samples showing a broader range of oxidation states and europium anomalies compared to the more stable REE fractionation dynamics in Tongling samples. These differences underscore the importance of detailed geochemical and mineralogical analyses for accurate provenance determination in gemmological and archaeological contexts.展开更多
The Minnan dialect,is characterized by its gentle tone and fluid rhythm.This dialect,with its rich history,has undergone significant evolution over the centuries.The earliest origins of the Minnan dialect can be trace...The Minnan dialect,is characterized by its gentle tone and fluid rhythm.This dialect,with its rich history,has undergone significant evolution over the centuries.The earliest origins of the Minnan dialect can be traced back to the Shang Dynasty,with its development linked to the Yellow River and the Luo River basin during the Western Jin Dynasty.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 11374118the Science Foundation of Hubei Province under Grant No 2013CFB289
文摘The sense of mammalian hearing exhibits nonlinear phenomena which are most significant to hearing function, such as nonlinear dynamic compression, nonlinear tuning and combination tones. These nonlinear phenomena are suggested to originate from the Hopf amplification within the cochlea, while the mechanism underlying the Hopf amplification remains elusive. According to the experimental results of force-gating channel operation in hair cells, through a theoretic model, this work reveals a velocity-dependent open probability of force-gating channels in auditory hair cells, and a velocity-dependent active force produced by the force-gating channel operating, which makes sensors hear typical Hopf vibrators with nonlinear hearing phenomena.
文摘Nanyang shadow puppetry has a long history.It originated in the Han Dynasty and grew from folk rap art,combining various art forms like painting,sculpture(雕塑),and opera.In the past,rural cultural life in Nanyang was rare;shadow puppetry was a key form of entertainment(娱乐).During festivals,temple fairs,or slack farming seasons,troupes would visit villages to give wonderful shows.
基金supported by the National Natural Science Foundation of China(Grant No.42072168)the National Key R&D Program of China(Grant No.2019YFC0605405)the Fundamental Research Funds for the Central Universities(Grant No.2023ZKPYDC07)。
文摘The different reservoirs in deep Songliao Basin have non-homogeneous lithologies and include multiple layers with a high content of hydrogen gas.The gas composition and stable isotope characteristics vary significantly,but the origin analysis of different gas types has previously been weak.Based on the geochemical parameters of gas samples from different depths and the analysis of geological settings,this research covers the diverse origins of natural gas in different strata.The gas components are mainly methane with a small amount of C_(2+),and non-hydrocarbon gases,including nitrogen(N_(2)),hydrogen(H_(2)),carbon dioxide(CO_(2)),and helium(He).At greater depth,the carbon isotope of methane becomes heavier,and the hydrogen isotope points to a lacustrine sedimentary environment.With increasing depth,the origins of N_(2)and CO_(2)change gradually from a mixture of organic and inorganic to inorganic.The origins of hydrogen gas are complex and include organic sources,water radiolysis,water-rock(Fe^(2+)-containing minerals)reactions,and mantle-derived.The shales of Denglouku and Shahezi Formations,as source rocks,provide the premise for generation and occurrence of organic gas.Furthermore,the deep faults and fluid activities in Basement Formation control the generation and migration of mantle-derived gas.The discovery of a high content of H_(2)in study area not only reveals the organic and inorganic association of natural-gas generation,but also provides a scientific basis for the exploration of deep hydrogen-rich gas.
基金the financial support received from The Key Project of R&D Program of Ningxia Hui Autonomous Region,China(2022BBF01003)China Agriculture Research System of MOF and MARA(CARS-29).
文摘Aging in oak barrels is widely used in enology which could bring flavor changes and aromatic complexity to wines.In the present study,the aroma compounds were analyzed from the‘Merlot’dry red wines,which were fermented in two types of fermenters(stainless steel tank and rotated oak barrel)and aged in six types of oak barrels(three geographic origins×two toasting degrees)for different time(0,3,6 and 9 months,respectively).Results showed that 30 volatiles were associated with barrels and increased during oak aging.The fermenters could influence the intensities of the toast,leathery,smoky,fruity,floral and caramel aromas.The concentration of whisky lactone,eugenol,cis-isoeugenol,and the intensities of the toast and spicy aromas were highest in the wines aged in American oak and were lowest in the wines aged in French oak barrels.The concentrations of guaiacol,syringol,trans-isoeugenol,furfural alcohol,vanilla,cis-whisky lactone enabled the medium toasting barrels to be distinguished from the light toasting ones.The compounds originating from the barrels could be used to distinguish the types of different barrels,but the other general grape-derived and fermentation-derived volatiles could not.The fermenters,oak species and toasting degrees of the barrels all had significant effects on the aroma profiles of the aged‘Merlot’dry red wines,but the influence of the geographic origin was not obvious.
基金supported by Doctor’s Scientific Research Initiation Project of Yan’an University(YAU202213093)National Natural Science Foundation of China(Grant No.41503029)。
文摘A total of 45 alkylbenzenes were detected and identified in crude oils with different depositional environments and thermal maturities from the Tarim Basin,Beibuwan Basin,and Songliao Basin using comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry(GC×GCTOFMS).By analyzing the distribution characteristics of C0-C5alkylbenzenes,it is found that the content of some alkylbenzenes varies greatly in crude oils.Based on the distribution characteristics of 1,2,4,5-tetramethylbenzene(Te MB)and 1,2,3,4-Te MB,the ratio of 1,2,4,5-Te MB to 1,2,3,4-Te MB is proposed to indicate the organic matter origin and depositional environment of ancient sediments.Oil samples originated mainly from lower hydrobiont,algae,bacteria and source rocks deposited under reducing/anoxic conditions have low 1,2,4,5-/1,2,3,4-Te MB values(less than 0.6),while oil samples originated mainly from terrestrial higher plants and source rocks deposited under oxic/sub-oxic conditions have higher 1,2,4,5-/1,2,3,4-Te MB values(greater than 1.0).The significant difference of 1,2,4,5-/1,2,3,4-Te MB values is controlled by 1,2,4,5-Te MB content.1,2,4,5-Te MB content in oils derived from source rocks deposited in oxidized sedimentary environment(greater than 1.0 mg/g whole oil)is higher than that in oils from source rocks deposited in reduced sedimentary environment(less than 1.0 mg/g whole oil).1,2,4,5-/1,2,3,4-Te MB ratio might not or slightly be affected by evaporative fractionation,biodegradation and thermal maturity.1,2,4,5-/1,2,3,4-Te MB ratio and 1,2,4,5-Te MB content can be used as supplementary parameter for the identification of sedimentary environment and organic matter input.It should be noted that compared to the identification of organic matter sources,the 1,2,4,5-/1,2,3,4-Te MB parameter is more effective in identifying sedimentary environments.
基金Supported by the National Natural Science Foundation of China(42172149,U2244209)Sinopec Science and Technology Research Project(P23230,P22132)。
文摘Based on the analysis of light hydrocarbon compositions of natural gas and regional comparison in combination with the chemical components and carbon isotopic compositions of methane,the indication of geochemical characteristics of light hydrocarbons on the migration features,dissolution and escape of natural gas from the Dongsheng gas field in the Ordos Basin is revealed,and the effect of migration on specific light hydrocarbon indexes is further discussed.The study indicates that,natural gas from the Lower Shihezi Formation(Pix)in the Dongsheng gas field displays higher iso-C5-7contents than n-C5-7contents,and the C6-7light hydrocarbons are composed of paraffins with extremely low aromatic contents(<0.4%),whereas the C7light hydrocarbons are dominated by methylcyclohexane,suggesting the characteristics of coal-derived gas with the influence by secondary alterations such as dissolution.The natural gas from the Dongsheng gas field has experienced free-phase migration from south to north and different degrees of dissolution after charging,and the gas in the Shiguhao area to the north of the Borjianghaizi fault has experienced apparent diffusion loss after accumulation.Long-distance migration in free phase results in the decrease of the relative contents of the methylcyclohexane in C7 light hydrocarbons and the toluene/n-heptane ratio,as well as the increase of the n-heptane/methylcyclohexane ratio and heptane values.The dissolution causes the increase of isoheptane values of the light hydrocarbons,whereas the diffusion loss of natural gas in the Shiguhao area results in the increase of n-C5-7contents compared to the iso-C5-7contents.
文摘Turquoise, a hydrous phosphate of copper and aluminum, is highly valued for its unique colour and historical significance. The similarity in colour, quality, and pattern between turquoises from different localities may lead to confusion in determining their origins. This is particularly evident in the case of turquoises from Meiduk in Iran and Tongling in China(Fig.1).In Iran, turquoise deposits are typically associated with magmatic zones, specifically in the Meiduk mine, located 85 kilometers northwest of the Sar Cheshmeh porphyry copper deposit in Kerman Province. The deposit is hosted by Eocene volcanic rocks of andesitic-basaltic composition with porphyry-type mineralization associated with two Miocene calc-alkaline intrusive phases. Five distinct zones of the hypogene alteration include potassic, potassic-phyllic, phyllic, and propylitic zones, which are rich in magnetite. Mineralization processes include stockwork, dissemination, veinlets, and veins rich in garnet, chalcopyrite, magnetite, and anhydrite. Turquoise is found in transitional, leached, and supergene zones, primarily as fracture and seam fillers. In contrast, Chinese turquoises are more often found in sedimentary rocks, with significant exceptions in places like the Tongling mine in Anhui Province, which are hosted within magmatic rocks. The turquoise from Tongling is found in the Tongling area within the Middle-lower Yangtze Metallogenic Belt, an area characterized by complex tectonics and intense magmatic and metallogenic activities. The turquoise deposits are associated with iron-copper polymetallic mineralization within Early Cretaceous volcanic rocks.The turquoise from Meiduk exhibited a specific gravity range of 2.22 g/cm^(3)to 2.71 g/cm^(3), SWUV fluorescence from none to medium, and LWUV fluorescence from faint to strong, indicating diverse mineralogical compositions. SEM examination of turquoise from Meiduk reveals a variety of mineral morphologies. The turquoise displays closely packed arrays of elongated needle-like crystals, measuring 2 μm to 9 μm in length and 0.1 μm to 0.4 μm in thickness, indicating a dynamic growth environment. The density and alignment of these crystals suggest the space-constrained setting, likely influenced by rapid deposition from mineral-laden fluids, with crystals interlocked due to simultaneous nucleation events. Some crystals appear similarly elongated but are more dispersed, with greater separation between individual crystals. In other areas, the elongated turquoise crystals are tightly intergrown, creating a dense textural appearance, pointing to a stage where growth space became limited, resulting in an interlocking matrix. Additionally, some crystals radiate outward from a central point, forming a spherical pattern reaching about 18 μm. The turquoise from Tongling show a specific gravity range of 2.26 g/cm^(3)to 2.60 g/cm^(3), with consistent medium SWUV fluorescence and strong LWUV fluorescence. SEM examination reveals needle structures, plate-like structures, and spheroidal aggregates composed of needle and plate-like microcrystals. These spherical aggregates, some with diameters around 26 μm, exhibit the concentric growth structure covered by turquoise microcrystals, with crystal lengths of 8 μm. The surface needle-like microcrystals vary in size, approximately 3 μm in length, 2 μm in width, and 0.2 to 0.6 μm in thickness.Optical microscopy, Raman and FTIR spectroscopy reported the presence of quartz, gypsum, iron oxides such as jarosite and goethite, biotite, sericite, pyrite, galena, bornite, graphene oxide, malachite, and azurite as major associated minerals of Meiduk's. In contrast, the Tongling mine features minerals such as quartz, anatase, barite, sodium feldspar, illite, and malachite.Through EPMA and LA-ICP-MS results, the turquoises of Tongling exhibit similar average iron content(1.28% and 1.26% respectively), but significant differences in copper content. The turquoises of Meiduk have the average copper content of 6.97%, whereas Tongling samples show the higher content of 11.38%. Na, K, and Ca concentrations are also higher in Meiduk samples, suggesting interaction with alkali-rich fluids and potassic alteration. Trace elements such as Ti, Cr, Zn, Se, and Mo serve as tracing agents for Meiduk samples, while Be and W are associated with Tongling samples. Regarding rare earth elements(REEs), Meiduk samples show diverse δCe(0.14-4.62) and δEu(0.65-15.78) values, indicating a wide range of oxidation states and europium anomalies. The significant variability in LREE/HREE ratios(0.39-31.74) and ΣREE concentrations(0.25-240.72 ppm) suggests heterogeneous REE fractionation patterns. In contrast, Tongling samples display δCe(0.070-2.51) and δEu(0.238-4.87) ranges, with more consistent LREE/HREE ratios(0.128-10.2) and ΣREE values(0.069-4.08 ppm), indicating stable REE fractionation dynamics.This comparative study of turquoises from the Meiduk mine in Iran and the Tongling mine in China reveals significant similarities and differences in their geochemical and mineralogical characteristics. Both deposits are hosted within magmatic rocks and produce turquoise as a byproduct in open-pit copper mining operations, exhibiting comparable colors, patterns, and morphologies. However, distinct differences are noted in their mineral compositions and trace elements, with turquoise from Meiduk associated with a complex hydrothermal system rich in various sulfide and oxide minerals and higher copper, Na, K, and Ca concentrations, indicating alkali-rich fluid interactions. In contrast, the turquoise from Tongling, influenced by both volcanic and sedimentary processes, shows a higher copper content, presence of barite, and different trace elements such as Be and W. The REE patterns also highlight the contrasting geological histories and environmental conditions at each site, with Meiduk samples showing a broader range of oxidation states and europium anomalies compared to the more stable REE fractionation dynamics in Tongling samples. These differences underscore the importance of detailed geochemical and mineralogical analyses for accurate provenance determination in gemmological and archaeological contexts.
文摘The Minnan dialect,is characterized by its gentle tone and fluid rhythm.This dialect,with its rich history,has undergone significant evolution over the centuries.The earliest origins of the Minnan dialect can be traced back to the Shang Dynasty,with its development linked to the Yellow River and the Luo River basin during the Western Jin Dynasty.
