This study presents an integrated study of the North China Craton (NCC) based on recent high resolution seismic images combined with observations on surface geology regional tectonics and mantle dynamics Seismic images reveal markedly concordant and rapid variations in crustal and lithospheric structure and thickness upper mantle anisotropy and discontinuity structures and thickness of the mantle transition zone near the boundary between the eastern and central parts of the NCC These rapid variations roughly coincide with the sudden change in both surface topography and gravity field as marked by the North-South Gravity Lineament (NSGL) Such a shallow-deep structural concordance may reflect different lithospheric tectonics and mantle processes in the two domains during the Phanerozoic reactivation of the craton Sharp structural variations are particularly present to the west of the NSGL especially between the Archean Ordos Plateau which retains the characteristics of a typical craton and the surrounding Cenozoic rift systems which are underlain by a significantly modified and thinned lithosphere These observations provide deep structural evidence that the Phanerozoic reactivation was not confined to the eastern NCC as previously thought but also affected areas in the central and western NCC though to a much lesser degree On both sides of the NSGL, lithospheric modification and thinning appear to be more pronounced along Paleoproterozoic belts suturing Archean blocks demonstrating the importance of pre-existing lithosphere scale structures in controlling the tectonic evolution of the NCC It further indicates that craton reactivation probably is common given the fact that structural heterogeneities are always present in cratonic regions The seismic structural images together with geological petrological geochemical and mineral physics data suggest that the fundamental destruction of the eastern NCC lithosphere may have been triggered largely by the deep subduction of the Pacific plate especially during the Late Mesozoic The complexity of deep structures and lithospheric properties in regions west of the NSGL may represent the relatively weak imprints of the Cenozoic India-Eurasia collision superposed upon that of the earlier tectonic events (C) 2009 Elsevier B V All rights reserved
I imaged the lithospheric structure beneath the Bohai Bay Basin (BBB) in the eastern North China Craton (NCC) and the Taihang Mountains JM) and areas further to the west in the central NCC by applying the wave equation migration technique to both the S- and P-receiver functions (RFs) collected in this region. The data images and synthetic modeling results indicate that S-RF imaging is more appropriate than P-RF imaging for mapping lithospheric discontinuities, especially the lithosphere-asthenosphere boundary (LAB) in various types of regions, even directly applicable to basin areas that are covered by thick sediments. The constructed S-RF images show that the lithospheric thickness of the study region is highly variable. The imaged LAB is on average similar to 80 km beneath the BBB, and displays obvious undulations from similar to 120 km under the TM to 40 km) under the mountain areas in the central NCC, consistent with previous P-RF imaging results. The observed structural differences between the eastern and central NCC are likely associated with different lithospheric tectonics in these two regions. While widespread lithosphere reactivation and extension in the eastern NCC during the late Mesozoic time was plausibly responsible for both the thinned crust and lithosphere in the BBB, lithospheric thinning in the central NCC may be equally heterogeneous but less significant, and probably occurred mainly in Cenozoic. Such a process may have given rise to the highly variable present-day lithospheric thickness in this region. However, it probably did not noticeably affect the overlying crust that was reported to have thickened in response to the early magmatic underplating in the Mesozoic time. The different tectonic processes in the eastern and central NCC may have induced the formation of the NSGL, which likely serves as a major tectonic boundary separating the two regions of contrasting lithospheric structures at present. (C) 2008 Elsevier B.V. All rights reserved.
We study intertwining operator algebras introduced and constructed by Huang. In the case that the intertwining operator algebras involve intertwining operators among irreducible modules for their vertex operator subalgebras, a number of results on intertwining operator algebras were given in [Y.-Z. Huang, Generalized rationality and a “Jacobi identity” for intertwining operator algebras, Selecta Math. (N.S.) 6 (2000) 225–267] but some of the proofs were postponed to an unpublished monograph. In this paper, we give the proofs of these results in [Y.-Z. Huang, Generalized rationality and a “Jacobi identity” for intertwining operator algebras, Selecta Math. (N.S.) 6 (2000) 225–267] and we formulate and prove results for general intertwining operator algebras without assuming that the modules involved are irreducible. In particular, we construct fusing and braiding isomorphisms for general intertwining operator algebras and prove that they satisfy the genus-zero Moore–Seiberg equations. We show that the Jacobi identity for intertwining operator algebras is equivalent to generalized rationality, commutativity and associativity properties of intertwining operator algebras. We introduce the locality for intertwining operator algebras and show that the Jacobi identity is equivalent to the locality, assuming that other axioms hold. Moreover, we establish that any two of the three properties, associativity, commutativity and skew-symmetry, imply the other (except that when deriving skew-symmetry from associativity and commutativity, more conditions are needed). Finally, we show that three definitions of intertwining operator algebras are equivalent.
Circular RNAs (circRNAs) are produced from precursor mRNA (pre-mRNA) back-splicing of thousands of genes in eukaryotes. Although circRNAs are generally expressed at low levels, recent findings have shed new light on their cell type-specific and tissue-specific expression and on the regulation of their biogenesis. Furthermore, the data indicate that circRNAs shape gene expression by titrating microRNAs, regulating transcription and interfering with splicing, thus effectively expanding the diversity and complexity of eukaryotic transcriptomes.
The asymmetric unit of the title compound, [Zn(C₁₁H₈O₅)(C₁₂H₈N₂)](n), is composed of a Zn(II) ion and 3-[3-(carboxyl-atometh-oxy)phen-yl]acrylate and 1,10-phenanthroline ligands. The Zn(II) ion adopts a distorted square-pyramidal ZnN₂O₃ coordination. The bridging mode of the dianion leads to the formation of zigzag chains parallel to . Intermolecular π-π stacking inter-actions [centroid-centroid distance of 3.5716 (12) Å] lead to the formation of a two-dimensional network parallel to (001).
The asymmetric unit of the title compound, [Zn(C11H8O5)(C12H8N2)]n, is composed of a ZnII ion and 3-[3-(carboxylatomethoxy)phenyl]acrylate and 1,10-phenanthroline ligands. The ZnII ion adopts a distorted square-pyramidal ZnN2O3 coordination. The bridging mode of the dianion leads to the formation of zigzag chains parallel to . Intermolecular π–π stacking interactions [centroid–centroid distance of 3.5716 (12) Å] lead to the formation of a two-dimensional network parallel to (001).