Ti-rich garnet is found within calcitic ijolite from the Oka carbonatite complex in Canada, which is characterized by 58%-73% andradite component(2.12 wt.%-4.18 wt.% TiO_2) and classified as melanite. The garnet dis...Ti-rich garnet is found within calcitic ijolite from the Oka carbonatite complex in Canada, which is characterized by 58%-73% andradite component(2.12 wt.%-4.18 wt.% TiO_2) and classified as melanite. The garnet displays complex zoning and contains abundant high field strength elements(HFSEs) and rare earth elements(REEs). Three groups(Ⅰ, Ⅱ, Ⅲ) have been identified based on their petrographic nature. Compared to groups Ⅱ and Ⅲ, Group Ⅰ garnet cores contain higher TiO_2, Mg O, HFSE, and REE and lower SiO_2 abundances. The distinct chemical and petrographic signatures of the investigated garnets cannot be attributed to simple closed system crystallization, but they are consistent with the multi-pulse magma mixing. Combined with previously reported U-Pb ages for apatite from the calcitic ijolite, at least three stages of magma evolution and subsequent mixing have been involved in the generation of calcitic ijolite at Oka. The early-formed melt that generated Group I garnet core was later mixed with at least two small-volume, more evolved melts. The intermediate stage melt formed the remaining garnet along with some pyroxene, calcite, nepheline, and apatite at 127±3.6 Ma. The youngest, most evolved melt generated the majority of pyroxene, calcite, nepheline, and apatite within the calcitic ijolite at 115±3.1 Ma.展开更多
This study presents a development of an advanced cyberbased database-enabled design module for low- rise buildings (DEDM-LR) which provides estimation of the wind-induced responses for main wind force resisting fram...This study presents a development of an advanced cyberbased database-enabled design module for low- rise buildings (DEDM-LR) which provides estimation of the wind-induced responses for main wind force resisting frames by making direct use of pressure time histories measured at a large number of pressure taps over a suite of building models. These responses may be considered in lieu of code-specified load effects in which the overall accuracy may be influenced by the inherent simplifications in codes. In addition, this new automated approach is particularly attractive and advantageous as it allows a web-based online analysis/design via intuitive user-friendly interfaces for both the input and output in terms of familiar web-style forms that are nowadays very common in most of web-based services. Presently, the DEDM-LR hosts an aerodynamic database developed by the Tokyo Polytechnic University (TPU), Japan for a variety of building configurations like flat, gable, and hip roofs under suburban terrain flow condition with immediate application to other databases. The paper shows the efficacy and validity of the DEDM-LR by walking through its details and examples on selected gable-roofed buildings. The architecture of DEDM-LR platform offers the ability to pool resources by hosting other databases that may become available in the near future.展开更多
基金supported by the National Natural Science Foundation of China (No. 41402046)the Fundamental Research Funds for the Central Universities (No. 2015219102)+1 种基金the special fund from the State Key Laboratory of Geological Processes and Mineral Resourcesfinancial support during her doctoral dissertation from the University of Notre Dame
文摘Ti-rich garnet is found within calcitic ijolite from the Oka carbonatite complex in Canada, which is characterized by 58%-73% andradite component(2.12 wt.%-4.18 wt.% TiO_2) and classified as melanite. The garnet displays complex zoning and contains abundant high field strength elements(HFSEs) and rare earth elements(REEs). Three groups(Ⅰ, Ⅱ, Ⅲ) have been identified based on their petrographic nature. Compared to groups Ⅱ and Ⅲ, Group Ⅰ garnet cores contain higher TiO_2, Mg O, HFSE, and REE and lower SiO_2 abundances. The distinct chemical and petrographic signatures of the investigated garnets cannot be attributed to simple closed system crystallization, but they are consistent with the multi-pulse magma mixing. Combined with previously reported U-Pb ages for apatite from the calcitic ijolite, at least three stages of magma evolution and subsequent mixing have been involved in the generation of calcitic ijolite at Oka. The early-formed melt that generated Group I garnet core was later mixed with at least two small-volume, more evolved melts. The intermediate stage melt formed the remaining garnet along with some pyroxene, calcite, nepheline, and apatite at 127±3.6 Ma. The youngest, most evolved melt generated the majority of pyroxene, calcite, nepheline, and apatite within the calcitic ijolite at 115±3.1 Ma.
文摘This study presents a development of an advanced cyberbased database-enabled design module for low- rise buildings (DEDM-LR) which provides estimation of the wind-induced responses for main wind force resisting frames by making direct use of pressure time histories measured at a large number of pressure taps over a suite of building models. These responses may be considered in lieu of code-specified load effects in which the overall accuracy may be influenced by the inherent simplifications in codes. In addition, this new automated approach is particularly attractive and advantageous as it allows a web-based online analysis/design via intuitive user-friendly interfaces for both the input and output in terms of familiar web-style forms that are nowadays very common in most of web-based services. Presently, the DEDM-LR hosts an aerodynamic database developed by the Tokyo Polytechnic University (TPU), Japan for a variety of building configurations like flat, gable, and hip roofs under suburban terrain flow condition with immediate application to other databases. The paper shows the efficacy and validity of the DEDM-LR by walking through its details and examples on selected gable-roofed buildings. The architecture of DEDM-LR platform offers the ability to pool resources by hosting other databases that may become available in the near future.