The complex distribution of gas hydrate in sediments makes understanding the mechanical properties of hydrate-bearing sediments a challenging task.The mechanical behaviors of hydrate-bearing interlayered sediments are...The complex distribution of gas hydrate in sediments makes understanding the mechanical properties of hydrate-bearing sediments a challenging task.The mechanical behaviors of hydrate-bearing interlayered sediments are still poorly known.A series of triaxial shearing tests were conducted to investigate the strength parameters and deformation properties of methane hydrate-bearing interlayered sediments at the effective pressure of 1 MPa.The results indicate that the stress-strain curves of hydrate-bearing interlayered sediments are significantly different from that of hydrate-bearing sediments.The peak strength,Young's modulus,initial yielding modulus,and failure mode are deeply affected by the methane hydrate distribution.The failure behaviors and mechanism of strain softening and hardening patterns of the interlayered specimens are more complicated than those of the integrated specimens.This study compares the different mechanical behaviors between integrated and interlayered specimens containing gas hydrate,which can serve as a reference for the prediction and analysis of the deformation behaviors of natural gas hydrate reservoirs.展开更多
The Turfan-Hami basin is the key area for the exploration of sandstone uranium deposits of the leachable interlayered oxidation zone type. The aim of this study is to shed light on the development characteristics of t...The Turfan-Hami basin is the key area for the exploration of sandstone uranium deposits of the leachable interlayered oxidation zone type. The aim of this study is to shed light on the development characteristics of this type of uranium deposits and provide new clues to further exploration. Detailed study led to the following conclusions: (1) uranium orebodies are hosted mainly in the lower Middle Jurassic Xishanyao Formation and the lower Lower Jurassic Badaowan Formation; (2) the formation of uranium orebodies is closely related to organic matter; (3) the front of the interlayered oxidation zone is snake-shaped in plane and imbricated in the section; the more the interlayered oxidation zone and zonation are developed, the better the uranium mineralization will be; according to lithological and geochemical characteristics, the oxidation zone, the oxidation-reduction transitional zone and the reduction zone can be distin-guished; (4) the development of interlayered oxidation zone is controlled by geological structure, underground water, sandstone permeability and other factors; (5) sandstone uranium orebodies hosted in the interlayered oxidation zone are very complicated in spatial distribution, of which some are rolled and plated in shape and some are highly variable in shape.展开更多
Al-pillared interlayered montmorillonite (Al-PILM) was prepared using the artificial Na-montmorillonite from the Qingfengshan bentonite mine as a starting material mixed with Al-pillaring solutions.The microstructure ...Al-pillared interlayered montmorillonite (Al-PILM) was prepared using the artificial Na-montmorillonite from the Qingfengshan bentonite mine as a starting material mixed with Al-pillaring solutions.The microstructure of the materials was studied by an X-ray powder diffractometer and a Fourier transform infrared (FTIR) spectrometer.The results indicated that the basal spacing [d(001) value] of the materials was increased significantly to 1.9194 nm relative to Na-montmorillonite (1.2182 nm).After calcined for 2 h at 300℃,the basal spacing was stabilized at 1.8394 nm and the layered structure of the materials was not destroyed.Thermal analysis was conducted by a thermal gravimetry and differential thermal analysis (TG-DTA) instrument,it showed that Al-PILM lost physically adsorbed water below 230.6℃ and water formed by dehydroxylation of the pillars at around 497.1℃, with a peak of the phase transformation at 903.0℃.展开更多
The particle-size distribution and mineralogical composition of the clay （〈 2 μm） and fine-sand （0.25-0.10 mm） fractions in soils of two inland valleys in Abakaliki and Bende, Southeast Nigeria, were investigate...The particle-size distribution and mineralogical composition of the clay （〈 2 μm） and fine-sand （0.25-0.10 mm） fractions in soils of two inland valleys in Abakaliki and Bende, Southeast Nigeria, were investigated to provide basic information on soil-forming processes and agricultural potentials. These soils were silty or clayey, deriving from Cretaceous or Tertiary shale materials. The particle-size distribution and its computation on a clay-free basis revealed relatively remarkable lithologic breaks in a couple of pedons. The effect of lithologic discontinuities on soil mineralogical composition was not, however, conspicuous. Petrographic investigation revealed that quartz predominantly comprised the fine-sand fraction in the soils at both study sites. Nevertheless, the clay mineralogical composition of the soils was a mixture of kaolinite, irregularly interstratified smectite-illite intergrades （S/I）, hydroxyl-A1 interlayered 2：1 type clays （HICs）, vermiculite, smectite, halloysite and illite along with fine-sized quartz in Abakaliki. The soils of Bende predominantly contained smectite, which was partially interlayered with hydroxyl-A1 and kaolinite. It is suggested that seasonal floodwater has slowed the disintegration of weatherable clay minerals inherited from the shale, while quartz originating from the sandstone is predominant in the fine-sand fraction. Additionally, a possible soil-forming process observed at the both study sites was ferrolysis, which was indicated by a clear decreasing pattern of HICs downward in the soil profiles, The entry of S/I and vertical distribution patterns for a couple of clay minerals in the pedon suggested that the soils in Abakaliki have developed under the significant influence of aeolian dust delivered by the Harmattan. The findings might describe a site-specific deposition pattern of Harmattan dusts as well as hydromorphic soil-forming processes in the wetlands of the inland valleys.展开更多
Aluminosilicate clay mineral(ACM)is a kind of typical raw materials that used widely in manufacturing industry owing to the abundant reserve and low-cost exploring.In past two decades,in-depth understanding on unique ...Aluminosilicate clay mineral(ACM)is a kind of typical raw materials that used widely in manufacturing industry owing to the abundant reserve and low-cost exploring.In past two decades,in-depth understanding on unique layered structure and abundant surface proper-ties endows ACM in the emerging research and application fields.In field of solar-chemical energy conversion,ACM has been widely used to support various semiconductor photocata-lysts,forming the composites and achieving efficient conversion of reactants under sunlight irradiation.To date,classic ACM such as kaolinite and montmorillonite,loaded with semi-conductor photocatalysts has been widely applied in photocatalysis.This review summaries the recent works on ACM-based composites in photocatalysis.Focusing on the properties of surface and layered structure,we elucidate the different features in the composition with various functional photocatalysts on two typical kinds of ACM,i.e.,type 1∶1 and type 2∶1.Not only large surface area and active surface hydroxyl group assist the substrate adsorption,but also the layered structure provides more space to enlarge the application of ACM-based photocatalysts.Besides,we overview the modifications on ACM from both external surface and the inter-layer space that make the formation of composites more efficiently and boost the photo-chemical process.This review could inspire more upcoming design and synthesis for ACM-based photocatalysts,leading this kind of economic and eco-friendly materials for more practical application in the future.展开更多
Limited information is available concerning the mineralogy of paddy soils in the southeastern China.Using chemical methods in conjunction with X-ray diffractometry, we studied the mineral composition of three paddy so...Limited information is available concerning the mineralogy of paddy soils in the southeastern China.Using chemical methods in conjunction with X-ray diffractometry, we studied the mineral composition of three paddy soils: Jinghua (paddy soil on Quaternary red clay), Fuyang (Hapl-percogenic loamy paddy soil), and Shaoxing (gleyic clayey paddy soil). All the soils contained quartz, mica, vermiculite, chlorite and kaolinite, and the distribution of these minerals varied with soil particle size fractions. The clay fraction of the F’uyang and Shaoxing soils also contained smectite. Although X-ray data did not show the presence of smectite in the Jinghua soil, this mineral was identified by the chemical method, suggesting a transitional property of the mineral in the soil. Hydroxy-Al interlayered minerals were also present in the clay fraction.The amount of smectite in the soils was 31.6 (Shaoxing), 16.5 (Fuyang), and 21.4 (Jinghua) g kg-1; for vermiculite it was 33.3 (Shaoxing), 16.5 (Fuyang), and 8.5 (Jinghua) g kg-1. Smectite was only found in the clay fraction. In contrast, amounts of vermiculite in soil particle size fractions were 3.0～11.4 (sand),2.1～6.0 (coarse silt), 4.6～18.9 (medium silt), 0.9～40.0 (fine silt), and 17.0～108 (clay) g kg-1. The amount of noncrystalline aluminosilicates in the soils in g kg-1 decreased in the order: Shaoxing (2.4) > Jinghua (1.9) > Fuyang (1.7). This study has provided useful mineralogical information that is fundamental in future developmellt of management strategies of the soils.展开更多
基金supported by the National Natural Science Foundation of China (No. 41976074)National Key Research and Development Plan (No. 2017YFC030 7600)+2 种基金the Taishan Scholar Special Experts Project (No. ts201712079)Qingdao National Laboratory for Marine Science and Technology (No. QNLM2016ORP0207)the Graduate School Innovation Program of China University of Petroleum (East China) (No. YCX2019020)
文摘The complex distribution of gas hydrate in sediments makes understanding the mechanical properties of hydrate-bearing sediments a challenging task.The mechanical behaviors of hydrate-bearing interlayered sediments are still poorly known.A series of triaxial shearing tests were conducted to investigate the strength parameters and deformation properties of methane hydrate-bearing interlayered sediments at the effective pressure of 1 MPa.The results indicate that the stress-strain curves of hydrate-bearing interlayered sediments are significantly different from that of hydrate-bearing sediments.The peak strength,Young's modulus,initial yielding modulus,and failure mode are deeply affected by the methane hydrate distribution.The failure behaviors and mechanism of strain softening and hardening patterns of the interlayered specimens are more complicated than those of the integrated specimens.This study compares the different mechanical behaviors between integrated and interlayered specimens containing gas hydrate,which can serve as a reference for the prediction and analysis of the deformation behaviors of natural gas hydrate reservoirs.
文摘The Turfan-Hami basin is the key area for the exploration of sandstone uranium deposits of the leachable interlayered oxidation zone type. The aim of this study is to shed light on the development characteristics of this type of uranium deposits and provide new clues to further exploration. Detailed study led to the following conclusions: (1) uranium orebodies are hosted mainly in the lower Middle Jurassic Xishanyao Formation and the lower Lower Jurassic Badaowan Formation; (2) the formation of uranium orebodies is closely related to organic matter; (3) the front of the interlayered oxidation zone is snake-shaped in plane and imbricated in the section; the more the interlayered oxidation zone and zonation are developed, the better the uranium mineralization will be; according to lithological and geochemical characteristics, the oxidation zone, the oxidation-reduction transitional zone and the reduction zone can be distin-guished; (4) the development of interlayered oxidation zone is controlled by geological structure, underground water, sandstone permeability and other factors; (5) sandstone uranium orebodies hosted in the interlayered oxidation zone are very complicated in spatial distribution, of which some are rolled and plated in shape and some are highly variable in shape.
文摘Al-pillared interlayered montmorillonite (Al-PILM) was prepared using the artificial Na-montmorillonite from the Qingfengshan bentonite mine as a starting material mixed with Al-pillaring solutions.The microstructure of the materials was studied by an X-ray powder diffractometer and a Fourier transform infrared (FTIR) spectrometer.The results indicated that the basal spacing [d(001) value] of the materials was increased significantly to 1.9194 nm relative to Na-montmorillonite (1.2182 nm).After calcined for 2 h at 300℃,the basal spacing was stabilized at 1.8394 nm and the layered structure of the materials was not destroyed.Thermal analysis was conducted by a thermal gravimetry and differential thermal analysis (TG-DTA) instrument,it showed that Al-PILM lost physically adsorbed water below 230.6℃ and water formed by dehydroxylation of the pillars at around 497.1℃, with a peak of the phase transformation at 903.0℃.
基金Project supported by the Grant-in-Aid of Japan Society for the Promotion of Science, Ministry of Education, Culture,Sports, Science and Technology (Nos. 15101002 and 19002001)
文摘The particle-size distribution and mineralogical composition of the clay （〈 2 μm） and fine-sand （0.25-0.10 mm） fractions in soils of two inland valleys in Abakaliki and Bende, Southeast Nigeria, were investigated to provide basic information on soil-forming processes and agricultural potentials. These soils were silty or clayey, deriving from Cretaceous or Tertiary shale materials. The particle-size distribution and its computation on a clay-free basis revealed relatively remarkable lithologic breaks in a couple of pedons. The effect of lithologic discontinuities on soil mineralogical composition was not, however, conspicuous. Petrographic investigation revealed that quartz predominantly comprised the fine-sand fraction in the soils at both study sites. Nevertheless, the clay mineralogical composition of the soils was a mixture of kaolinite, irregularly interstratified smectite-illite intergrades （S/I）, hydroxyl-A1 interlayered 2：1 type clays （HICs）, vermiculite, smectite, halloysite and illite along with fine-sized quartz in Abakaliki. The soils of Bende predominantly contained smectite, which was partially interlayered with hydroxyl-A1 and kaolinite. It is suggested that seasonal floodwater has slowed the disintegration of weatherable clay minerals inherited from the shale, while quartz originating from the sandstone is predominant in the fine-sand fraction. Additionally, a possible soil-forming process observed at the both study sites was ferrolysis, which was indicated by a clear decreasing pattern of HICs downward in the soil profiles, The entry of S/I and vertical distribution patterns for a couple of clay minerals in the pedon suggested that the soils in Abakaliki have developed under the significant influence of aeolian dust delivered by the Harmattan. The findings might describe a site-specific deposition pattern of Harmattan dusts as well as hydromorphic soil-forming processes in the wetlands of the inland valleys.
基金This work was supported by the National Natural Science Foundation of China(21976054)the National Key Research and Development Program of China(2017YFA0207002)Beijing Outstanding Young Scientist Program.
文摘Aluminosilicate clay mineral(ACM)is a kind of typical raw materials that used widely in manufacturing industry owing to the abundant reserve and low-cost exploring.In past two decades,in-depth understanding on unique layered structure and abundant surface proper-ties endows ACM in the emerging research and application fields.In field of solar-chemical energy conversion,ACM has been widely used to support various semiconductor photocata-lysts,forming the composites and achieving efficient conversion of reactants under sunlight irradiation.To date,classic ACM such as kaolinite and montmorillonite,loaded with semi-conductor photocatalysts has been widely applied in photocatalysis.This review summaries the recent works on ACM-based composites in photocatalysis.Focusing on the properties of surface and layered structure,we elucidate the different features in the composition with various functional photocatalysts on two typical kinds of ACM,i.e.,type 1∶1 and type 2∶1.Not only large surface area and active surface hydroxyl group assist the substrate adsorption,but also the layered structure provides more space to enlarge the application of ACM-based photocatalysts.Besides,we overview the modifications on ACM from both external surface and the inter-layer space that make the formation of composites more efficiently and boost the photo-chemical process.This review could inspire more upcoming design and synthesis for ACM-based photocatalysts,leading this kind of economic and eco-friendly materials for more practical application in the future.
文摘Limited information is available concerning the mineralogy of paddy soils in the southeastern China.Using chemical methods in conjunction with X-ray diffractometry, we studied the mineral composition of three paddy soils: Jinghua (paddy soil on Quaternary red clay), Fuyang (Hapl-percogenic loamy paddy soil), and Shaoxing (gleyic clayey paddy soil). All the soils contained quartz, mica, vermiculite, chlorite and kaolinite, and the distribution of these minerals varied with soil particle size fractions. The clay fraction of the F’uyang and Shaoxing soils also contained smectite. Although X-ray data did not show the presence of smectite in the Jinghua soil, this mineral was identified by the chemical method, suggesting a transitional property of the mineral in the soil. Hydroxy-Al interlayered minerals were also present in the clay fraction.The amount of smectite in the soils was 31.6 (Shaoxing), 16.5 (Fuyang), and 21.4 (Jinghua) g kg-1; for vermiculite it was 33.3 (Shaoxing), 16.5 (Fuyang), and 8.5 (Jinghua) g kg-1. Smectite was only found in the clay fraction. In contrast, amounts of vermiculite in soil particle size fractions were 3.0～11.4 (sand),2.1～6.0 (coarse silt), 4.6～18.9 (medium silt), 0.9～40.0 (fine silt), and 17.0～108 (clay) g kg-1. The amount of noncrystalline aluminosilicates in the soils in g kg-1 decreased in the order: Shaoxing (2.4) > Jinghua (1.9) > Fuyang (1.7). This study has provided useful mineralogical information that is fundamental in future developmellt of management strategies of the soils.
基金supported by the National Natural Science Foundation of China(50976050,51150110155,51176077)Key Special Technologies R&D Program of Tianjin(09ZCKFSH01900)~~
