In the present study,the mechanical properties of polyvinyl alcohol(PVA)-basalt hybrid fiber reinforced engineered cementitious composites(ECC)after exposure to elevated temperatures were experimentally investigated.F...In the present study,the mechanical properties of polyvinyl alcohol(PVA)-basalt hybrid fiber reinforced engineered cementitious composites(ECC)after exposure to elevated temperatures were experimentally investigated.Five temperatures of 20,50,100,200 and 400℃ were set to evaluate the residual compressive,tensile and flexural behaviors of hybrid and mono fiber ECC.It was shown that partial replacement of PVA fibers with basalt fibers endowed ECC with improved residual compressive toughness,compared to brittle failure of mono fiber ECC heated to 400℃.The tension tests indicated that the presence of basalt fibers benefited the tensile strength up to 200℃,and delayed the sharp reduction of strength to 400℃.Under flexural load,the peak deflections corresponding to flexural strengths of hybrid fiber ECC were found to be less vulnerable ranging from 20 to 100℃.Further,the scanning electron microscopy(SEM)results uncovered that the rupture of basalt fiber at moderate temperature and its pullout mechanism at high temperature was responsible for the mechanical evolution of hybrid fiber ECC.This work develops a better understanding of elevated temperature and basalt fiber impact on the residual mechanical properties and further provides guideline for tailoring ECC for improved fire resistance.展开更多
Diyarbaklr basalt aquifer is volcanic-rock aquifers which contain high quality water. It was main resources for Diyarbaklr city center drinking supply up to 2005. Somewhere, basalt aquifer groundwater is still used fo...Diyarbaklr basalt aquifer is volcanic-rock aquifers which contain high quality water. It was main resources for Diyarbaklr city center drinking supply up to 2005. Somewhere, basalt aquifer groundwater is still used for irrigation in rural areas of Diyarbaklr city. In the study, Diyarbaklr city center＇s （which is located on the Tigris river basin） basalt aquifer groundwater potentials and hydrogeological features are examined and modeled by using GIS programmer. Firstly, general geological data, meteorological data and general information about natural water sources are collected together, afterwards, logs of well drilled by public institutions and private individuals within the Diyarbaklr city center are analyzed. Static water level, dynamic water level and well pumps yields are classified in these logs. Then, thematic maps produced with the help of Arc Info Professional GIS programmer with geostatistical analyst tool. Groundwater source potential of Diyarbaktr is examined by means of these thematic maps. In hydrogeological research, productivity by aquifer features, water retention capacity and groundwater level data evaluated with geological structure of area are taken into consideration.展开更多
The macro- and microscopic results were that this body of basalt tectonically heavily loaded, strongly altered by clay minerals and characterized by hydro-metasomatic alteration. The geochemical analyzes revealed that...The macro- and microscopic results were that this body of basalt tectonically heavily loaded, strongly altered by clay minerals and characterized by hydro-metasomatic alteration. The geochemical analyzes revealed that the original magma could be a mantle origin of high iron and magnesium containing basalt （tholeiites, 10%-15%）. As regards to the palaeogeographic environment, it can be said that due to the periodic sea flooding, it pushed into a lower area, covered with sediment where the surrounding areas were highlighted （biikkszentkereszt and bukkszentlaszl6 tufts）.展开更多
Ji Kang＇s ＂An Essay on Nourishing Life＂ has, for much of its history, been overshadowed by his more famous work ＂Sound is without Grief or Joy.＂ Be that as it may, ＂An Essay on Nourishing Life＂ is also an impor...Ji Kang＇s ＂An Essay on Nourishing Life＂ has, for much of its history, been overshadowed by his more famous work ＂Sound is without Grief or Joy.＂ Be that as it may, ＂An Essay on Nourishing Life＂ is also an important text in that it delves into the interdependence of the heart-mind, spirit, and vital breath, and into how harmony between them is the key to ensuring physical longevity. In addition to investigating this aspect of his thought, this paper will also discuss Ji Kang＇s attention to the vicissitudes of knowledge and desire and to the need to temper them with tranquility and stillness. ＂An Essay on Nourishing Life＂ can thus be read as an extension of classical Daoist theories of self-cultivation while at the same time elaborating upon them by bringing together their disparate components into a coherently unified doctrine.展开更多
Forty-two Cenozoic （mostly Miocene） basalt samples from Jining, Chifeng, Fansi, Xiyang, and Zuoquan areas of the North China Craton （the NCC basalts hereafter） were analyzed for platinum-group elements （PGE, incl...Forty-two Cenozoic （mostly Miocene） basalt samples from Jining, Chifeng, Fansi, Xiyang, and Zuoquan areas of the North China Craton （the NCC basalts hereafter） were analyzed for platinum-group elements （PGE, including Os, It, Ru, Rh, Pt, and Pd）. Most of them are alkaline basalts and tholeiites and all of them display little crustal contamination. The total PGE contents of the NCC basalts vary from 0.1 to 0.9 ppb, much lower than those of the primitive mantle values of 23.5 ppb. Primitive man- tie-normalized PGE patterns of these basalts define positive slopes and Pd/Ir ratios vary from 1.2 to 25. In terms of both PGE contents and Pd/Ir ratios, they are quite similar to the mid-ocean ridge basalts. There are no obvious negative correlations be- tween PGE vs. MgO, Ni, and Cu in the NCC basalts, indicating that fractional crystallization of olivine, pyroxene, and/or sul- fides during magmatic process cannot be the controlling factor for the observed PGE variation. The observed Pd/Ir variations of the NCC basalts require involvement of non-chondritic heterogeneous mantle sources. Based on Sr-Nd-Pb-Hf isotopic sys- tematics and incompatible-element signatures, a mixing of partial melts from both asthenospheric peridotites and enclosed mantle eclogites at the top of asthenosphere was proposed for the origin of these NCC basalts. The lenses of eclogites are de- rived from upwelling of recycled continental crust during the westward subduction of the Pacific plate from the -600 km dis- continuity zone. The PGE geochemistry of these basalts provides independent evidence to support this conclusion and the ob- served Pd/Ir variations may reflect variations in proportions of tapped peridotitic and eclogitic melts.展开更多
The geochemical study of the Earth's mantle provides important constraints on our understanding of the formation and evolution of Earth, its internal structure, and the mantle dynamics. The bulk Earth composition ...The geochemical study of the Earth's mantle provides important constraints on our understanding of the formation and evolution of Earth, its internal structure, and the mantle dynamics. The bulk Earth composition is inferred by comparing terrestrial mantle rocks with chondrites, which leads to the chondritic Earth model. That is, Earth has the same relative proportions of refractory elements as that in chondrites, but it is depleted in volatiles. Ocean island basalts(OIB) may be produced by mantle plumes with possible deep origins; consequently, they provide unique opportunity to study the deep Earth. Isotopic variations within OIB can be described using a limited number of mantle endmembers, such as EM1, EM2 and HIMU, and they have been used to decipher important mantle processes. Introduction of crustal material into the deep mantle via subduction and delamination is important in generating mantle heterogeneity; however, there is active debate on how they were sampled by mantle melting, i.e.,the role of olivine-poor lithologies in the OIB petrogenesis. The origin and location of high 3He/4He mantle remain controversial,ranging from unprocessed(or less processed) primitive material in the lower mantle to highly processed materials with shallow origins, including ancient melting residues, mafic cumulates under arcs, and recycled hydrous minerals. Possible core-mantle interaction was hypothesized to introduce distinctive geochemical signatures such as radiogenic 186 Os and Fe and Ni enrichment in the OIB. Small but important variations in some short-lived nuclides, including 142 Nd, 182 W and several Xe isotopes, have been reported in ancient and modern terrestrial rocks, implying that the Earth's mantle must have been differentiated within the first 100 Myr of its formation, and the mantle is not efficiently homogenized by mantle convection.展开更多
基金Project(51808545)supported by the National Natural Science Foundation of ChinaProject(8184083)supported by the Beijing Natural Science Foundation,ChinaProject(2021YQLJ05)supported by the Fundamental Research Funds for the Central Universities,China。
文摘In the present study,the mechanical properties of polyvinyl alcohol(PVA)-basalt hybrid fiber reinforced engineered cementitious composites(ECC)after exposure to elevated temperatures were experimentally investigated.Five temperatures of 20,50,100,200 and 400℃ were set to evaluate the residual compressive,tensile and flexural behaviors of hybrid and mono fiber ECC.It was shown that partial replacement of PVA fibers with basalt fibers endowed ECC with improved residual compressive toughness,compared to brittle failure of mono fiber ECC heated to 400℃.The tension tests indicated that the presence of basalt fibers benefited the tensile strength up to 200℃,and delayed the sharp reduction of strength to 400℃.Under flexural load,the peak deflections corresponding to flexural strengths of hybrid fiber ECC were found to be less vulnerable ranging from 20 to 100℃.Further,the scanning electron microscopy(SEM)results uncovered that the rupture of basalt fiber at moderate temperature and its pullout mechanism at high temperature was responsible for the mechanical evolution of hybrid fiber ECC.This work develops a better understanding of elevated temperature and basalt fiber impact on the residual mechanical properties and further provides guideline for tailoring ECC for improved fire resistance.
文摘Diyarbaklr basalt aquifer is volcanic-rock aquifers which contain high quality water. It was main resources for Diyarbaklr city center drinking supply up to 2005. Somewhere, basalt aquifer groundwater is still used for irrigation in rural areas of Diyarbaklr city. In the study, Diyarbaklr city center＇s （which is located on the Tigris river basin） basalt aquifer groundwater potentials and hydrogeological features are examined and modeled by using GIS programmer. Firstly, general geological data, meteorological data and general information about natural water sources are collected together, afterwards, logs of well drilled by public institutions and private individuals within the Diyarbaklr city center are analyzed. Static water level, dynamic water level and well pumps yields are classified in these logs. Then, thematic maps produced with the help of Arc Info Professional GIS programmer with geostatistical analyst tool. Groundwater source potential of Diyarbaktr is examined by means of these thematic maps. In hydrogeological research, productivity by aquifer features, water retention capacity and groundwater level data evaluated with geological structure of area are taken into consideration.
文摘The macro- and microscopic results were that this body of basalt tectonically heavily loaded, strongly altered by clay minerals and characterized by hydro-metasomatic alteration. The geochemical analyzes revealed that the original magma could be a mantle origin of high iron and magnesium containing basalt （tholeiites, 10%-15%）. As regards to the palaeogeographic environment, it can be said that due to the periodic sea flooding, it pushed into a lower area, covered with sediment where the surrounding areas were highlighted （biikkszentkereszt and bukkszentlaszl6 tufts）.
文摘Ji Kang＇s ＂An Essay on Nourishing Life＂ has, for much of its history, been overshadowed by his more famous work ＂Sound is without Grief or Joy.＂ Be that as it may, ＂An Essay on Nourishing Life＂ is also an important text in that it delves into the interdependence of the heart-mind, spirit, and vital breath, and into how harmony between them is the key to ensuring physical longevity. In addition to investigating this aspect of his thought, this paper will also discuss Ji Kang＇s attention to the vicissitudes of knowledge and desire and to the need to temper them with tranquility and stillness. ＂An Essay on Nourishing Life＂ can thus be read as an extension of classical Daoist theories of self-cultivation while at the same time elaborating upon them by bringing together their disparate components into a coherently unified doctrine.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.41173036,40534022)the Chinese Academy of Sciences(Grant No.KZCX2-YW-103)
文摘Forty-two Cenozoic （mostly Miocene） basalt samples from Jining, Chifeng, Fansi, Xiyang, and Zuoquan areas of the North China Craton （the NCC basalts hereafter） were analyzed for platinum-group elements （PGE, including Os, It, Ru, Rh, Pt, and Pd）. Most of them are alkaline basalts and tholeiites and all of them display little crustal contamination. The total PGE contents of the NCC basalts vary from 0.1 to 0.9 ppb, much lower than those of the primitive mantle values of 23.5 ppb. Primitive man- tie-normalized PGE patterns of these basalts define positive slopes and Pd/Ir ratios vary from 1.2 to 25. In terms of both PGE contents and Pd/Ir ratios, they are quite similar to the mid-ocean ridge basalts. There are no obvious negative correlations be- tween PGE vs. MgO, Ni, and Cu in the NCC basalts, indicating that fractional crystallization of olivine, pyroxene, and/or sul- fides during magmatic process cannot be the controlling factor for the observed PGE variation. The observed Pd/Ir variations of the NCC basalts require involvement of non-chondritic heterogeneous mantle sources. Based on Sr-Nd-Pb-Hf isotopic sys- tematics and incompatible-element signatures, a mixing of partial melts from both asthenospheric peridotites and enclosed mantle eclogites at the top of asthenosphere was proposed for the origin of these NCC basalts. The lenses of eclogites are de- rived from upwelling of recycled continental crust during the westward subduction of the Pacific plate from the -600 km dis- continuity zone. The PGE geochemistry of these basalts provides independent evidence to support this conclusion and the ob- served Pd/Ir variations may reflect variations in proportions of tapped peridotitic and eclogitic melts.
基金supported by the National Science Foundation (Grant No. NSF EAR-1524387)National Natural Science Foundation of China (Grant No. 41590620)
文摘The geochemical study of the Earth's mantle provides important constraints on our understanding of the formation and evolution of Earth, its internal structure, and the mantle dynamics. The bulk Earth composition is inferred by comparing terrestrial mantle rocks with chondrites, which leads to the chondritic Earth model. That is, Earth has the same relative proportions of refractory elements as that in chondrites, but it is depleted in volatiles. Ocean island basalts(OIB) may be produced by mantle plumes with possible deep origins; consequently, they provide unique opportunity to study the deep Earth. Isotopic variations within OIB can be described using a limited number of mantle endmembers, such as EM1, EM2 and HIMU, and they have been used to decipher important mantle processes. Introduction of crustal material into the deep mantle via subduction and delamination is important in generating mantle heterogeneity; however, there is active debate on how they were sampled by mantle melting, i.e.,the role of olivine-poor lithologies in the OIB petrogenesis. The origin and location of high 3He/4He mantle remain controversial,ranging from unprocessed(or less processed) primitive material in the lower mantle to highly processed materials with shallow origins, including ancient melting residues, mafic cumulates under arcs, and recycled hydrous minerals. Possible core-mantle interaction was hypothesized to introduce distinctive geochemical signatures such as radiogenic 186 Os and Fe and Ni enrichment in the OIB. Small but important variations in some short-lived nuclides, including 142 Nd, 182 W and several Xe isotopes, have been reported in ancient and modern terrestrial rocks, implying that the Earth's mantle must have been differentiated within the first 100 Myr of its formation, and the mantle is not efficiently homogenized by mantle convection.
