Hydroisomerization catalysts Pt/ZSM-22, Pt/ZSM-23, and Pt/ZSM-22/ZSM-23 were prepared by supporting Pt on ZSM-22, ZSM-23, and intergrowth zeolite ZSM-22/ZSM-23, respectively. The typical physicochemical properties of ...Hydroisomerization catalysts Pt/ZSM-22, Pt/ZSM-23, and Pt/ZSM-22/ZSM-23 were prepared by supporting Pt on ZSM-22, ZSM-23, and intergrowth zeolite ZSM-22/ZSM-23, respectively. The typical physicochemical properties of these catalysts were characterized by X-Ray Diffraction （XRD）, N2 absorption-desorption, Pyridine-Fourier Transform Infrared （Py-FTIR）, Transmission Electron Microscopy （TEM）, X-Ray Fluorescence （XRF）, Scanning Electron Microscopy （SEM） and NH3- Temperature Programmed Desorption （NH3-TPD）, and the performance of these catalysts in n-dodecane hydroisomerization was evaluated in a continuous down-flow fixed bed with a stainless steel tubular reactor. The characterization results indicated that the intergrowth zeolite ZSM-22/ZSM-23 possessed the dual structure of ZSM-22 and ZSM-23, and the catalyst Pt/ZSM-22/ZSM-23 had similar pores and weak acidity to Pt/ZSM-22 and Pt/ZSM-23 catalysts. Moreover, Pt/ZSM-22/ZSM-23 catalyst showed a high selectivity in hydroisomerization of long chain n-alkanes to mono-branched isomers. The evaluation results for n-dodecane hydroisomerization indicated that the activity of Pt/ZSM-22/ZSM-23 was the lowest, while the hydroisomerization selectivity was the highest among the three catalysts. The maximum yield of i-dodecane product was 68.3% over Pt/ZSM-22/ZSM-23 at 320 ℃.展开更多
Jiangjia Ravine is a world-famous debris flow valley in Dongchuan,Yunnan Province,China.Every year large numbers of landslides and collapses happened and caused enormous damages to people's properties and lives.Wi...Jiangjia Ravine is a world-famous debris flow valley in Dongchuan,Yunnan Province,China.Every year large numbers of landslides and collapses happened and caused enormous damages to people's properties and lives.With longtime observation and testing in Jiangjia Ravine we had found out one kind of special landslide which had the characteristics of landslide and collapse.Landslide and collapse supplied sufficient materials for debris flow.When a debris flow broke out,some kind of intergrowth existed among rainfall,landslide and debris flow.In order to study the intergrowth and some key parameters,we carried out artificial rainfall landslide tests and model experiments to observe the phenomena such as collapse,surface slide and surface flow.By observing the experimental phenomena and monitoring water contents,the transformation process among landslide deposits and debris flow under the condition of rainfall had been analyzed.Research results revealed the relationship of this kind of intergrowth among rainfall,landslide and debris flow in Jiangjia Ravine.Meanwhile,it was found that this kind of intergrowth relationship existed only when the moisture content was in a certain range.That is,the critical state seemed to be existed in the transformation process.展开更多
TS-2 microspheres,consisting of intergrown primary nanocrystals,was prepared by controlling the synthetic parameters.The effects of the amount of quaternary ammonium cations as structure-directing agent,H2O/Si ratio,t...TS-2 microspheres,consisting of intergrown primary nanocrystals,was prepared by controlling the synthetic parameters.The effects of the amount of quaternary ammonium cations as structure-directing agent,H2O/Si ratio,the presence of alcohol and the temperature were carefully investigated on the crystallization process.The high alkalinity was proved to be highly important for the preservation of the microsphere morphology initially formed,due to the unique intergrown stacking style.An alkali treatment with the aqueous solution of structure-directing agent,organic amine and ammonium salt and subsequent Na+ion-exchange were performed to enhance the catalytic activity of TS-2 microsphere in the cyclohexanone ammoximation reactions,with both the conversion and selectivity higher than 99%.In the continuous reaction,the TS-2 microspheres exhibited to be durable catalyst with potential application in industrial ammoximation processes.展开更多
By calculation of thermodynamics,analysis of crystal structure and study of TEM and eletron probe,it is first discovered that SiO2 can be acted as one of the heterogeneous nu- clei for lamellar intergorowth eutectic(a...By calculation of thermodynamics,analysis of crystal structure and study of TEM and eletron probe,it is first discovered that SiO2 can be acted as one of the heterogeneous nu- clei for lamellar intergorowth eutectic(austenite and cementite)crystallizing in modified as-cast medium manganese steel.展开更多
ZSM-5 plates with a perpendicular intergrowth structure was synthesized by using a simple amine as the structure directing agent under hydrothermal conditions,in which the mother plate and the perpendicularly standing...ZSM-5 plates with a perpendicular intergrowth structure was synthesized by using a simple amine as the structure directing agent under hydrothermal conditions,in which the mother plate and the perpendicularly standing plates oriented along the(010)and(100)planes of MFI crystals,respectively.During the crystallization process,the mother plate was initially formed on the surface of the amorphous solid gel,while a set of parallel plates perpendicularly grew on its surface,via a homogeneous nucleation mechanism.The mother plate and the perpendicular plates had a similar thickness of 100-200 nm and were characterized by considerably shortened straight and zigzag 10 member ring pores,respectively.This unique intergrowth structure greatly facilitated the diffusion of the reactive molecules in HZSM-5 crystals during methanol conversion to hydrocarbons.展开更多
The microstructural characteristics of syntactic polycrystal in the calcium rare earth fluorocarbonate minerals from Southwest China have been studied by means of selected area electron diffraction and high resolutio...The microstructural characteristics of syntactic polycrystal in the calcium rare earth fluorocarbonate minerals from Southwest China have been studied by means of selected area electron diffraction and high resolution electron microscopy(HREM). The complication of the heterogeneous fabric of the minerals have been revealed by HREM. The results show that the crystal structure of the minerals was formed by a disorder stacking of the unit layers of bast naesite and synchisite in the calcium rare earth fluorocarbonate minerals along c direction. The stacking fault and other crystal defects in the syntactic polycrystal have been discussed.展开更多
The integrated planting and breeding of paddy fields is a kind of eco-planting and breeding mode which makes rice and aquatic animals benefit from each other,greatly reducing the harm of rice pests and diseases,using ...The integrated planting and breeding of paddy fields is a kind of eco-planting and breeding mode which makes rice and aquatic animals benefit from each other,greatly reducing the harm of rice pests and diseases,using less or even no fertilizers or pesticides,greatly reducing the agricultural non-point source pollution,thus achieving the " multiple use of water,multiple harvests in one field,grain and fishing winwin,ecological and high efficient use. " In this paper,the high yield and efficient cultivation techniques of rice under the rice-fish intergrowth model in Chengdu was introduced from the aspects of selecting good paddy fields for fishing,using appropriate rice varieties,soaking disinfection,timely sowing and nurturing strong seedlings,reasonable close planting,reasonable fertilization,scientific water management,scientific pest control and rice harvests.展开更多
Ore textures and electron microprobe analyses show that in addition to highly scattered blebs in sphalerite grains, intergrown chalcopyrite also occurs as reds, myrrmekites andlamellae aligned along cleavages and twin...Ore textures and electron microprobe analyses show that in addition to highly scattered blebs in sphalerite grains, intergrown chalcopyrite also occurs as reds, myrrmekites andlamellae aligned along cleavages and twin boundaries of the host sphalerite. The majority of theintergrowths could have been formed by replacement of sphalerite by chalcopyrite, albeit part ofthem may have resulted from exsolution. Not only copper, but also iron were introduced intothe sphalerite by replacive fluids.While the front of the replacing fluid was moving forward through a sulphide orebody, Znand Pb were dissolved and Cu was precipitated, resulting in zonal refining of the sulphide ores.The remobilized zinc and lead were precipitated at favourable sites with changed physiccrchemical conditions. This is a Possible mechanism for the formation of copper-poor zinc and lead oresabove or lateral to the copper orebodies in some of the massive sulphide deceits reworked andoverprinted by late-stage granites and their hydrothermal fluids.展开更多
Copper possesses very strong chacophile properties,but under the conditions found in meteorites,its behavior is like that of siderophile elements.The Suizhou meteorite is a highly shocked L6 chondrite.Troilite and tae...Copper possesses very strong chacophile properties,but under the conditions found in meteorites,its behavior is like that of siderophile elements.The Suizhou meteorite is a highly shocked L6 chondrite.Troilite and taenite are considered the main primary carrier of copper in this meteorite,and the post-shock thermal episode is considered the main reason that elemental Cu migrates from its original host phase and forms metallic grains.The Suizhou meteorite contains a few very thin shock melt veins.The occurrence and behavior of metallic copper in this meteorite were studied by optical microscopic examination,electron microprobe analyses,and high-resolution X-ray elemental intensity mapping.Our results show that metallic copper is abundant in the Suizhou chondritic rock.Metallic copper grains adjacent to small troilite grains inside FeNi metal are the most common occurrence,and those at the FeNi metal–troilite interface are the second most common case.The metallic copper grains occurring at the interface of FeNi metal/troililte and silicate are rather rare.Metallic copper grains are not observed within the Suizhou shock veins,Instead,Cu in elemental form is transferred through shock metamorphism into FeNi metal+troilite intergrowths.Four diff erent occurrence types of Cu in the FeNi metal+troilite intergrowths have been identifi ed:the concentrations of Cu in the FeNi+FeS intergrowths for four occurrence types are rather close,we estimate it might be lower than 1 wt%.展开更多
The interplay and intergrowth characteristic of faceted intermetallic compounds(IMCs)during solidification was originally investigated through the rod-like Al3 Ni crystals in the liquid Al/solid Ni interconnection by ...The interplay and intergrowth characteristic of faceted intermetallic compounds(IMCs)during solidification was originally investigated through the rod-like Al3 Ni crystals in the liquid Al/solid Ni interconnection by using synchrotron radiography,and the diversified 3-D morphologies were reconstructed by synchrotron tomography.A spatial geometric model was established to effectively predict the diversified growth patterns of two spatial crystals.For the two overlapping Al3 Ni crystals,the impeded crystal growth was divided into three different stages,decided by the hindrance form the other crystal.Further,the groove formed on the crystal surface is directly related to the solute redistribution under the critical condition of boundary layer thickness larger than two crystals distance.The closer distance and smaller crystal size indicate the deeper and larger groove,and the morphology changes from hemispheroid to hemi-ellipsoid with the increased opposite and interacted faces.展开更多
Lattice match and charge transfer between distinct block layers(BLs)play an important role in the formation of an intergrowth structure.Herein we propose a simple BL model addressing the different roles of the lattice...Lattice match and charge transfer between distinct block layers(BLs)play an important role in the formation of an intergrowth structure.Herein we propose a simple BL model addressing the different roles of the lattice match and the charge transfer.Inter-BL charge transfer lowers the internal energy,while lattice match minimizes the elastic energy,both of which together make the intergrowth structure stabilized.The model is able to reproduce the lattice parameters precisely for complex iron-based superconductors with intergrowth structures.The elastic energy and the charge-transfer energy are evaluated with assistance of the first-principles calculations.This work rationalizes the basic principles of BL design for intergrowth structures,which can be utilized not only for finding new superconducting materials but also for investigating other layered materials with various functionalities.展开更多
以铁皮石斛(Dendrobium officinale Kimura et Migo)为实验材料,探索不同树种附生栽培对铁皮石斛的影响。结果表明:附生沉香处理能显著提高铁皮石斛的各项生长指标;附生花梨有助于提高铁皮石斛中总黄酮和粗纤维含量,附生橡胶和荔枝能显...以铁皮石斛(Dendrobium officinale Kimura et Migo)为实验材料,探索不同树种附生栽培对铁皮石斛的影响。结果表明:附生沉香处理能显著提高铁皮石斛的各项生长指标;附生花梨有助于提高铁皮石斛中总黄酮和粗纤维含量,附生橡胶和荔枝能显著提高铁皮石斛的醇浸出物;通过隶属函数法综合评价发现,附生于沉香树上对铁皮石斛生长与品质综合促进效果最佳,综合得分0.70。展开更多
Ⅰ. OCCURRENCE AND GENERAL FEATURES OF LONGQUAN MAGNESIOAMPHIBOLEThe magnesioamphibole studied in this note was sampled from peridotite block in Longquan tectonic melange zone of Zhejiang Province, China. It appears i...Ⅰ. OCCURRENCE AND GENERAL FEATURES OF LONGQUAN MAGNESIOAMPHIBOLEThe magnesioamphibole studied in this note was sampled from peridotite block in Longquan tectonic melange zone of Zhejiang Province, China. It appears in bunchy or fibrous aggregates around the block. The length of the crystal ranges from several mm to about 1 cm. It presents inchned extinction with cANg= 10°—13°under crossed polars. According to the observation of thin sections, it is known that olivine, tale and serpentine展开更多
Solid solution alloying is a promising strategy to establish high performance thermoelectrics.By alloying different elements,phase structures and phase compositions may vary accompanied by appearance of variety of int...Solid solution alloying is a promising strategy to establish high performance thermoelectrics.By alloying different elements,phase structures and phase compositions may vary accompanied by appearance of variety of interesting microstructures including mass fluctuation,lattice strain,nano-scale defects and spinodal decomposition,all of which may greatly influence the electrical and specifically the thermal transport of the material.In the present study,atomic structures of Cu_(2)S_(0.5)Se_(0.5) solid solution have been examined by using atom-resolved electron microscopy in order to investigate the structure-correlated physical insights for the abnormal thermal transport in this solid solution.Then the exceptional intergrowth nanostructures were observed.The solid solution consists of two high symmetrical phases,i.e.the hexagonal and cubic phase,which alternately intergrow to form highly oriented ultra-thin lamellae of nano or even,unit cell scales.The compositional oscillation in Se/S atomic ratio during alloying is responsible for the phase stability and intergrowth nanostructures.The unique binary phase intergrowth nanostructures make great contribution to the ultra-low lattice thermal conductivity comparable to glass and extremely short phonon mean free path of only 1.04Å,peculiar continuous hexagonal-to-cubic structural transformation without a critical transition temperature and its corresponding abnormal changes of thermal characters with temperatures.The present study further evokes the unlimited possibilities and potentials for tailoring nanostructures by alloying for improved thermoelectric performance.展开更多
基金the financial supports form Petrochina(050508-04-02)the National Natural Science Foundation of China(No.21073235,and 20833011)
文摘Hydroisomerization catalysts Pt/ZSM-22, Pt/ZSM-23, and Pt/ZSM-22/ZSM-23 were prepared by supporting Pt on ZSM-22, ZSM-23, and intergrowth zeolite ZSM-22/ZSM-23, respectively. The typical physicochemical properties of these catalysts were characterized by X-Ray Diffraction （XRD）, N2 absorption-desorption, Pyridine-Fourier Transform Infrared （Py-FTIR）, Transmission Electron Microscopy （TEM）, X-Ray Fluorescence （XRF）, Scanning Electron Microscopy （SEM） and NH3- Temperature Programmed Desorption （NH3-TPD）, and the performance of these catalysts in n-dodecane hydroisomerization was evaluated in a continuous down-flow fixed bed with a stainless steel tubular reactor. The characterization results indicated that the intergrowth zeolite ZSM-22/ZSM-23 possessed the dual structure of ZSM-22 and ZSM-23, and the catalyst Pt/ZSM-22/ZSM-23 had similar pores and weak acidity to Pt/ZSM-22 and Pt/ZSM-23 catalysts. Moreover, Pt/ZSM-22/ZSM-23 catalyst showed a high selectivity in hydroisomerization of long chain n-alkanes to mono-branched isomers. The evaluation results for n-dodecane hydroisomerization indicated that the activity of Pt/ZSM-22/ZSM-23 was the lowest, while the hydroisomerization selectivity was the highest among the three catalysts. The maximum yield of i-dodecane product was 68.3% over Pt/ZSM-22/ZSM-23 at 320 ℃.
基金financially supported by the National Natural Science Foundation of China(Grant No.50709035,40672193)the Youth Science and Technology Dawn Plan of Wuhan,China(Grant No.20065004116-42)
文摘Jiangjia Ravine is a world-famous debris flow valley in Dongchuan,Yunnan Province,China.Every year large numbers of landslides and collapses happened and caused enormous damages to people's properties and lives.With longtime observation and testing in Jiangjia Ravine we had found out one kind of special landslide which had the characteristics of landslide and collapse.Landslide and collapse supplied sufficient materials for debris flow.When a debris flow broke out,some kind of intergrowth existed among rainfall,landslide and debris flow.In order to study the intergrowth and some key parameters,we carried out artificial rainfall landslide tests and model experiments to observe the phenomena such as collapse,surface slide and surface flow.By observing the experimental phenomena and monitoring water contents,the transformation process among landslide deposits and debris flow under the condition of rainfall had been analyzed.Research results revealed the relationship of this kind of intergrowth among rainfall,landslide and debris flow in Jiangjia Ravine.Meanwhile,it was found that this kind of intergrowth relationship existed only when the moisture content was in a certain range.That is,the critical state seemed to be existed in the transformation process.
文摘TS-2 microspheres,consisting of intergrown primary nanocrystals,was prepared by controlling the synthetic parameters.The effects of the amount of quaternary ammonium cations as structure-directing agent,H2O/Si ratio,the presence of alcohol and the temperature were carefully investigated on the crystallization process.The high alkalinity was proved to be highly important for the preservation of the microsphere morphology initially formed,due to the unique intergrown stacking style.An alkali treatment with the aqueous solution of structure-directing agent,organic amine and ammonium salt and subsequent Na+ion-exchange were performed to enhance the catalytic activity of TS-2 microsphere in the cyclohexanone ammoximation reactions,with both the conversion and selectivity higher than 99%.In the continuous reaction,the TS-2 microspheres exhibited to be durable catalyst with potential application in industrial ammoximation processes.
基金The projected was supported by National Natural Science Foundation of China
文摘By calculation of thermodynamics,analysis of crystal structure and study of TEM and eletron probe,it is first discovered that SiO2 can be acted as one of the heterogeneous nu- clei for lamellar intergorowth eutectic(austenite and cementite)crystallizing in modified as-cast medium manganese steel.
文摘ZSM-5 plates with a perpendicular intergrowth structure was synthesized by using a simple amine as the structure directing agent under hydrothermal conditions,in which the mother plate and the perpendicularly standing plates oriented along the(010)and(100)planes of MFI crystals,respectively.During the crystallization process,the mother plate was initially formed on the surface of the amorphous solid gel,while a set of parallel plates perpendicularly grew on its surface,via a homogeneous nucleation mechanism.The mother plate and the perpendicular plates had a similar thickness of 100-200 nm and were characterized by considerably shortened straight and zigzag 10 member ring pores,respectively.This unique intergrowth structure greatly facilitated the diffusion of the reactive molecules in HZSM-5 crystals during methanol conversion to hydrocarbons.
文摘The microstructural characteristics of syntactic polycrystal in the calcium rare earth fluorocarbonate minerals from Southwest China have been studied by means of selected area electron diffraction and high resolution electron microscopy(HREM). The complication of the heterogeneous fabric of the minerals have been revealed by HREM. The results show that the crystal structure of the minerals was formed by a disorder stacking of the unit layers of bast naesite and synchisite in the calcium rare earth fluorocarbonate minerals along c direction. The stacking fault and other crystal defects in the syntactic polycrystal have been discussed.
文摘The integrated planting and breeding of paddy fields is a kind of eco-planting and breeding mode which makes rice and aquatic animals benefit from each other,greatly reducing the harm of rice pests and diseases,using less or even no fertilizers or pesticides,greatly reducing the agricultural non-point source pollution,thus achieving the " multiple use of water,multiple harvests in one field,grain and fishing winwin,ecological and high efficient use. " In this paper,the high yield and efficient cultivation techniques of rice under the rice-fish intergrowth model in Chengdu was introduced from the aspects of selecting good paddy fields for fishing,using appropriate rice varieties,soaking disinfection,timely sowing and nurturing strong seedlings,reasonable close planting,reasonable fertilization,scientific water management,scientific pest control and rice harvests.
文摘Ore textures and electron microprobe analyses show that in addition to highly scattered blebs in sphalerite grains, intergrown chalcopyrite also occurs as reds, myrrmekites andlamellae aligned along cleavages and twin boundaries of the host sphalerite. The majority of theintergrowths could have been formed by replacement of sphalerite by chalcopyrite, albeit part ofthem may have resulted from exsolution. Not only copper, but also iron were introduced intothe sphalerite by replacive fluids.While the front of the replacing fluid was moving forward through a sulphide orebody, Znand Pb were dissolved and Cu was precipitated, resulting in zonal refining of the sulphide ores.The remobilized zinc and lead were precipitated at favourable sites with changed physiccrchemical conditions. This is a Possible mechanism for the formation of copper-poor zinc and lead oresabove or lateral to the copper orebodies in some of the massive sulphide deceits reworked andoverprinted by late-stage granites and their hydrothermal fluids.
基金supported by Science and Technology Planning Project of Guangdong Province,2023B1212060048.
文摘Copper possesses very strong chacophile properties,but under the conditions found in meteorites,its behavior is like that of siderophile elements.The Suizhou meteorite is a highly shocked L6 chondrite.Troilite and taenite are considered the main primary carrier of copper in this meteorite,and the post-shock thermal episode is considered the main reason that elemental Cu migrates from its original host phase and forms metallic grains.The Suizhou meteorite contains a few very thin shock melt veins.The occurrence and behavior of metallic copper in this meteorite were studied by optical microscopic examination,electron microprobe analyses,and high-resolution X-ray elemental intensity mapping.Our results show that metallic copper is abundant in the Suizhou chondritic rock.Metallic copper grains adjacent to small troilite grains inside FeNi metal are the most common occurrence,and those at the FeNi metal–troilite interface are the second most common case.The metallic copper grains occurring at the interface of FeNi metal/troililte and silicate are rather rare.Metallic copper grains are not observed within the Suizhou shock veins,Instead,Cu in elemental form is transferred through shock metamorphism into FeNi metal+troilite intergrowths.Four diff erent occurrence types of Cu in the FeNi metal+troilite intergrowths have been identifi ed:the concentrations of Cu in the FeNi+FeS intergrowths for four occurrence types are rather close,we estimate it might be lower than 1 wt%.
基金the National Natural Science Foundation of China-Excellent Young Scholars(No.51922068)the National Natural Science Foundation of China(Nos.51727802,51821001,51904186 and 51904187)+2 种基金the Project funded by China Postdoctoral Science Foundation(No.2019M661500)Open Project of State Key Laboratory of Advanced Special Steel,Shanghai Key Laboratory of Advanced Ferrometallurgy,Shanghai University(SKLASS 2019-21)the Science and Technology Commission of Shanghai Municipality(No.19DZ2270200)。
文摘The interplay and intergrowth characteristic of faceted intermetallic compounds(IMCs)during solidification was originally investigated through the rod-like Al3 Ni crystals in the liquid Al/solid Ni interconnection by using synchrotron radiography,and the diversified 3-D morphologies were reconstructed by synchrotron tomography.A spatial geometric model was established to effectively predict the diversified growth patterns of two spatial crystals.For the two overlapping Al3 Ni crystals,the impeded crystal growth was divided into three different stages,decided by the hindrance form the other crystal.Further,the groove formed on the crystal surface is directly related to the solute redistribution under the critical condition of boundary layer thickness larger than two crystals distance.The closer distance and smaller crystal size indicate the deeper and larger groove,and the morphology changes from hemispheroid to hemi-ellipsoid with the increased opposite and interacted faces.
基金This work is supported by the National Key Research and Development Program of China(No.2017YFA0303002)the National Natural Science Foundation of China(No.12050003)the Fundamental Research Funds for the Central Universities of China.
文摘Lattice match and charge transfer between distinct block layers(BLs)play an important role in the formation of an intergrowth structure.Herein we propose a simple BL model addressing the different roles of the lattice match and the charge transfer.Inter-BL charge transfer lowers the internal energy,while lattice match minimizes the elastic energy,both of which together make the intergrowth structure stabilized.The model is able to reproduce the lattice parameters precisely for complex iron-based superconductors with intergrowth structures.The elastic energy and the charge-transfer energy are evaluated with assistance of the first-principles calculations.This work rationalizes the basic principles of BL design for intergrowth structures,which can be utilized not only for finding new superconducting materials but also for investigating other layered materials with various functionalities.
文摘以铁皮石斛(Dendrobium officinale Kimura et Migo)为实验材料,探索不同树种附生栽培对铁皮石斛的影响。结果表明:附生沉香处理能显著提高铁皮石斛的各项生长指标;附生花梨有助于提高铁皮石斛中总黄酮和粗纤维含量,附生橡胶和荔枝能显著提高铁皮石斛的醇浸出物;通过隶属函数法综合评价发现,附生于沉香树上对铁皮石斛生长与品质综合促进效果最佳,综合得分0.70。
文摘Ⅰ. OCCURRENCE AND GENERAL FEATURES OF LONGQUAN MAGNESIOAMPHIBOLEThe magnesioamphibole studied in this note was sampled from peridotite block in Longquan tectonic melange zone of Zhejiang Province, China. It appears in bunchy or fibrous aggregates around the block. The length of the crystal ranges from several mm to about 1 cm. It presents inchned extinction with cANg= 10°—13°under crossed polars. According to the observation of thin sections, it is known that olivine, tale and serpentine
基金This work was financially supported by the National Natural Science Foundation of China(Nos.51672296,51625205 and51902199)the Science and Technology Commission of ShanghaiMunicipality(No.16DZ2260603)the Shanghai Technical Platform for Testing and Characterization on Inorganic Materials(No.19DZ2290700)。
文摘Solid solution alloying is a promising strategy to establish high performance thermoelectrics.By alloying different elements,phase structures and phase compositions may vary accompanied by appearance of variety of interesting microstructures including mass fluctuation,lattice strain,nano-scale defects and spinodal decomposition,all of which may greatly influence the electrical and specifically the thermal transport of the material.In the present study,atomic structures of Cu_(2)S_(0.5)Se_(0.5) solid solution have been examined by using atom-resolved electron microscopy in order to investigate the structure-correlated physical insights for the abnormal thermal transport in this solid solution.Then the exceptional intergrowth nanostructures were observed.The solid solution consists of two high symmetrical phases,i.e.the hexagonal and cubic phase,which alternately intergrow to form highly oriented ultra-thin lamellae of nano or even,unit cell scales.The compositional oscillation in Se/S atomic ratio during alloying is responsible for the phase stability and intergrowth nanostructures.The unique binary phase intergrowth nanostructures make great contribution to the ultra-low lattice thermal conductivity comparable to glass and extremely short phonon mean free path of only 1.04Å,peculiar continuous hexagonal-to-cubic structural transformation without a critical transition temperature and its corresponding abnormal changes of thermal characters with temperatures.The present study further evokes the unlimited possibilities and potentials for tailoring nanostructures by alloying for improved thermoelectric performance.
