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Lesser Himalayan sequences in Eastern Himalaya and their deformation:Implications for Paleoproterozoic tectonic activity along the northern margin of India 被引量:5
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作者 Dilip Saha 《Geoscience Frontiers》 SCIE CAS CSCD 2013年第3期289-304,共16页
Substantial part of the northern margin of Indian plate is subducted beneath the Eurasian plate during the Caenozoic Himalayan orogeny, obscuring older tectonic events in the Lesser Himalaya known to host Proterozoic ... Substantial part of the northern margin of Indian plate is subducted beneath the Eurasian plate during the Caenozoic Himalayan orogeny, obscuring older tectonic events in the Lesser Himalaya known to host Proterozoic sedimentary successions and granitic bodies. Tectonostratigraphic units of the Proterozoic Lesser Himalayan sequence (LHS) of Eastern Himalaya, namely the Daling Group in Sikkim and the Bomdila Group in Arunachal Pradesh, provide clues to the nature and extent of Proterozoic passive margin sedimentation, their involvement in pre-Himalayan orogeny and implications for supercontinent reconstruction. The Daling Group, consisting of flaggy quartzite, meta-greywacke and metapelite with minor mafic dyke and sill, and the overlying Buxa Formation with stromatolitic carbonate-quartzite- slate, represent shallow marine, passive margin platformal association. Similar lithostratigraphy and broad depositional framework, and available geochronological data from intrusive granites in Eastern Himalaya indicate strikewise continuity of a shallow marine Paleoproterozoic platformal sequence up to Arunachal Pradesh through Bhutan. Multiple fold sets and tectonic foliations in LHS formed during partial or complete closure of the sea/ocean along the northern margin of Paleoproterozoic India. Such deformation fabrics are absent in the upper Palaeozoic-Mesozoic Gondwana formations in the Lesser Himalaya of Darjeeling-Sikkim indicating influence of older orogeny. Kinematic analysis based on microstructure, and garnet composition suggest Paleoproterozoic deformation and metamorphism of LHS to be distinct from those associated with the foreland propagating thrust systems of the Caenozoic Himalayan collisional belt. Two possibilities are argued here: (1) the low greenschist facies domain in the LHS enveloped the amphibolite to granulite facies domains, which were later tectonically severed; (2) the older deformation and metamorphism relate to a Pacific type accretionary orogen which affected the northern margin of greater India. Better understanding of geodynamic evolution of the northern margin of India in the Paleoproterozoic has additional bearing on more refined model of reconstruction of Colllrnhia. 展开更多
关键词 Garnet composition Kinematics Lesser Himalayan sequence Microstructure Paleoproterozoic Supercontinent
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Design Optimization of CFRP Stacking Sequence Using a Multi-Island Genetic Algorithms Under Low-velocity Impact Loads 被引量:3
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作者 王宏晓 段玉岗 +1 位作者 ABULIZI Dilimulati ZHANG Xiaohui 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2017年第3期720-725,共6页
A method to improve the low-velocity impact performance of composite laminate is proposed, and a multi-island genetic algorithm is used for the optimization of composite laminate stacking sequence under low-velocity i... A method to improve the low-velocity impact performance of composite laminate is proposed, and a multi-island genetic algorithm is used for the optimization of composite laminate stacking sequence under low-velocity impact loads based on a 2D dynamic impact finite element analysis. Low-velocity impact tests and compression-after impact(CAI) tests have been conducted to verify the effectiveness of optimization method. Experimental results show that the impact damage areas of the optimized laminate have been reduced by 42.1% compared to the baseline specimen, and the residual compression strength has been increased by 10.79%, from baseline specimen 156.97 MPa to optimized 173.91 MPa. The tests result shows that optimization method can effectively enhance the impact performances of the laminate. 展开更多
关键词 multi-island genetic algorithm low-velocity impact composite laminate stacking sequence
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STACKING SEQUENCE OPTIMIZA-TION OF LAMINATED COMPOSITE CYLINDER SHELL FOR MAXIMAL BUCKLING LOAD 被引量:4
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作者 TANG Qian LIAO Xiaoyun GAO Zhan 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2008年第4期31-34,共4页
A new optimization method for the optimization of stacking of composite glass fiber laminates is developed. The fiber orientation and angle of the layers of the cylindrical shells are sought considering the buckling l... A new optimization method for the optimization of stacking of composite glass fiber laminates is developed. The fiber orientation and angle of the layers of the cylindrical shells are sought considering the buckling load. The proposed optimization algorithm applies both finite element analysis and the mode-pursuing sampling (MPS)method. The algorithms suggest the optimal stacking sequence for achieving the maximal buckling load. The procedure is implemented by integrating ANSYS and MATLAB. The stacking sequence designing for the symmetric angle-ply three-layered and five-layered composite cylinder shells is presented to illustrate the optimization process, respectively. Compared with the genetic algorithms, the proposed optimization method is much faster and efficient for composite staking sequence plan. 展开更多
关键词 Composite Laminated cylindrical shell Stacking sequence optimization Buckling load Sampling algorithms
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THE EFFECT OF MONOMERS FEEDING METHODS ON EMULSION COPOLYMERIZATION OF VINYLIDENE CHLORIDE AND ACRYLATES
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作者 余鼎声 唐少华 焦书科 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1994年第1期66-72,共7页
The emulsion copolymerization of vinylidene chloride (VDC) with methyl-methacrylate(MMA) and acrylonitrile (AN) was carried out by batch, seeded batch and semicontinuous pro-cesses,respectively. Significant difference... The emulsion copolymerization of vinylidene chloride (VDC) with methyl-methacrylate(MMA) and acrylonitrile (AN) was carried out by batch, seeded batch and semicontinuous pro-cesses,respectively. Significant differences were found in the physical and mechanical propertiesof the latexes and films, depending on the methods of monomer feeding. The results both intheory and experiments demonstrated that the copolymer composition and the length of the VDC sequences in the copolymer could be controlled by the modes of monomer feeding process. 展开更多
关键词 Vinylidene chloride Methyl methacrylate ACRYLONITRILE Emulsion polymerization Feeding modes sequence distribution of copolymers composition
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Exploring Sequence Space to Design Controllable G-Quadruplex Topology Switches 被引量:1
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作者 Jielin Chen Mingpan Cheng +4 位作者 Petr Stadlbauer JiříŠponer Jean-Louis Mergny Huangxian Ju Jun Zhou 《CCS Chemistry》 CAS 2022年第9期3036-3050,共15页
As nonclassical nucleic acid structures,G-quadruplexes(G4s)not only play important roles in gene regulation and stability maintenance,but are also widely used in nanotechnology.Structural diversity is one of the main ... As nonclassical nucleic acid structures,G-quadruplexes(G4s)not only play important roles in gene regulation and stability maintenance,but are also widely used in nanotechnology.Structural diversity is one of the main factors explaining the popularity of G4s,but a comprehensive and integrated study of different factors determining G4 structural versatility is currently lacking. 展开更多
关键词 G-QUADRUPLEX G-quadruplex topology Gswitch sequence composition structural versatility
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