This article is a contribution to the study of the automorphism groups of designs. Let be a non-trivial design where for some positive integer , and is block-transitive. If the socle of G is iso...This article is a contribution to the study of the automorphism groups of designs. Let be a non-trivial design where for some positive integer , and is block-transitive. If the socle of G is isomorphic to the simple groups of lie type, then G is not flag-transitive.展开更多
In this paper we prove the following Theorem. Let G be a group and M a Suzuki-Ree group. Then G?M if and only if i)π_c(G) = π_c(M), where π_c(G) is the set of orders of elements in G, and ii) |G| = |M|.
Detailed REE and trace elements geochemical studies of the Zhoutan Group metasedimentary rocks in central Jiangxi Province, China, and rock-forming minerals such as garnet were conducted and the results showed that th...Detailed REE and trace elements geochemical studies of the Zhoutan Group metasedimentary rocks in central Jiangxi Province, China, and rock-forming minerals such as garnet were conducted and the results showed that the REEs are partly present in the rock-forming minerals and are dominantly contained in the lattice of accessory minerals. In the process of metamorphism the REEs between garnet porphyroblast and rock and the partitioning of REEs between garnet and the host rock is obviously controlled by the chemical composition of the system. The REEs compositions of metamorphic veins and their minerals display remarked lanthanide tetrad effects and the element pairs Zr-Hf, Y-Ho, Pb-Nd and U-Th have also experienced a certain degree of fractionation with respect to the metasedimentary rocks and they can be used as discriminating indicators to some extent for the occurrence of fluid processes in the process of metamorphism of the Zhoutan Group.展开更多
Geochemical studies on REE, trace elements and oxygen isotopes from metamorphic veins and their host metasedimentary rocks in the Zhoutan Group at two localities, Xiangshan and Yihuang, in central Jiangxi Province hav...Geochemical studies on REE, trace elements and oxygen isotopes from metamorphic veins and their host metasedimentary rocks in the Zhoutan Group at two localities, Xiangshan and Yihuang, in central Jiangxi Province have been conducted in this paper. The results show that the metamorphic quartz veins inherited the REE and oxygen isotope geochemical characteristics from their host rocks, suggesting that the vein-forming fluids were derived from the host rocks. Additionally, fractionation degrees of the trace element pairs Zr-Hf, Nb-Ta, Y-Ho and U-Th in the veins are different from those of their host rocks. It is also indicated that the veins are the products of the fluids. The metamorphic veins within the Zhoutan Group metasedimentary rocks were formed principally as a result of lateral diffusion of the metamorphic fluids.展开更多
The Late Archean Fuping Group of the Xiaojiao area in Pingshan County, HebeiProvince consists mainly of three metamorphic rock types of supracrustal affinity, i. e., K-feldspar leucoleptite, biotite leptite-gneiss and...The Late Archean Fuping Group of the Xiaojiao area in Pingshan County, HebeiProvince consists mainly of three metamorphic rock types of supracrustal affinity, i. e., K-feldspar leucoleptite, biotite leptite-gneiss and hornblendic rocks. Their anatectic derivativesformed in the initial stage of anatexis are petrochemically of K-feldspar granitic, trondhjemiticand granodioritic compositions respectively, and in general have inherited the main petrochemi-cal features from their parent rock types. Probably due to the fact that they contain less REE-rich accessory minerals as compared with their parent rocks, the anatectic derivatives are ingeneral lower in ∑REE content. But both the derivatives and their parent rocks have similarREE patterns, which serves as an additional indication of the genetic relationship betweenthem.展开更多
文摘This article is a contribution to the study of the automorphism groups of designs. Let be a non-trivial design where for some positive integer , and is block-transitive. If the socle of G is isomorphic to the simple groups of lie type, then G is not flag-transitive.
基金Project partially supported by the National Natural Science Foundation of China.
文摘In this paper we prove the following Theorem. Let G be a group and M a Suzuki-Ree group. Then G?M if and only if i)π_c(G) = π_c(M), where π_c(G) is the set of orders of elements in G, and ii) |G| = |M|.
基金supported jointly by the National Natural Science Foundation of China (40673061)the Ministry of Science and Technology of China (95-Pre-39)the Foundation of State Key Laboratory for Mineral Deposits Research, Nanjing University
文摘Detailed REE and trace elements geochemical studies of the Zhoutan Group metasedimentary rocks in central Jiangxi Province, China, and rock-forming minerals such as garnet were conducted and the results showed that the REEs are partly present in the rock-forming minerals and are dominantly contained in the lattice of accessory minerals. In the process of metamorphism the REEs between garnet porphyroblast and rock and the partitioning of REEs between garnet and the host rock is obviously controlled by the chemical composition of the system. The REEs compositions of metamorphic veins and their minerals display remarked lanthanide tetrad effects and the element pairs Zr-Hf, Y-Ho, Pb-Nd and U-Th have also experienced a certain degree of fractionation with respect to the metasedimentary rocks and they can be used as discriminating indicators to some extent for the occurrence of fluid processes in the process of metamorphism of the Zhoutan Group.
基金supported jointly by the Ministry of Science and Technology of China (95-Pre-39)the Foundation of State Key Laboratory for Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences (SKLEG7021)
文摘Geochemical studies on REE, trace elements and oxygen isotopes from metamorphic veins and their host metasedimentary rocks in the Zhoutan Group at two localities, Xiangshan and Yihuang, in central Jiangxi Province have been conducted in this paper. The results show that the metamorphic quartz veins inherited the REE and oxygen isotope geochemical characteristics from their host rocks, suggesting that the vein-forming fluids were derived from the host rocks. Additionally, fractionation degrees of the trace element pairs Zr-Hf, Nb-Ta, Y-Ho and U-Th in the veins are different from those of their host rocks. It is also indicated that the veins are the products of the fluids. The metamorphic veins within the Zhoutan Group metasedimentary rocks were formed principally as a result of lateral diffusion of the metamorphic fluids.
文摘The Late Archean Fuping Group of the Xiaojiao area in Pingshan County, HebeiProvince consists mainly of three metamorphic rock types of supracrustal affinity, i. e., K-feldspar leucoleptite, biotite leptite-gneiss and hornblendic rocks. Their anatectic derivativesformed in the initial stage of anatexis are petrochemically of K-feldspar granitic, trondhjemiticand granodioritic compositions respectively, and in general have inherited the main petrochemi-cal features from their parent rock types. Probably due to the fact that they contain less REE-rich accessory minerals as compared with their parent rocks, the anatectic derivatives are ingeneral lower in ∑REE content. But both the derivatives and their parent rocks have similarREE patterns, which serves as an additional indication of the genetic relationship betweenthem.
