Commercially available lattices contain various kinds of morphological imperfections which result in great degradation in lattices＇ mechanical properties, therefore, to obtain imperfection insensitive lattice structu...Commercially available lattices contain various kinds of morphological imperfections which result in great degradation in lattices＇ mechanical properties, therefore, to obtain imperfection insensitive lattice structure is obviously a practical research subject. Hierarchical structure materials were found to be a class of promising anti-defect materials, This paper builds hierarchical lattice by adding soft adhesion to lattice＇s cell edges and numerical results show that its imperfection sensitivity to missing bars is minor compared with the classic lattice. Soft adhesion with appropriate properties reinforce cell edge＇s bending stiffness and thus reduce the bending deformation in lattice caused by missing bars defect, which is confirmed by statistical analysis of normalized node displacements of imperfect lattices under hydrostatic compression and shear loads.展开更多
The Huichizi granite complex is the largest Paleozoic 1-type intrusion located in the North Qinling orogenic belt （NQB）. In this study, we present systematic geochemical element data, zircon U-Pb ages, Ln-Hf isotopi...The Huichizi granite complex is the largest Paleozoic 1-type intrusion located in the North Qinling orogenic belt （NQB）. In this study, we present systematic geochemical element data, zircon U-Pb ages, Ln-Hf isotopic data, and Sr-Nd isotopic data for the Huichizi granites. In terms of mineral and chemical compositions, these granites are biotite monzonitic and alkali-feldspar granites, both of which are characterized by high SiO2 and total alkali contents and low MgO, TiO2, and TFeO contents. These granites are weakly peraluminous （A/CNK values are 1-1.06 for biotite mon- zonitic granites and 1.04-1.09 for alkali-feldspar granites） and possess the geochemical characteristics of adakitic rocks, e.g., high Sr contents （319 ppm-633 ppm）, Sr/Y ratios （18.5-174）, and （La/Yb）N ratios （17.6-57） and low MgO （0.04 wt.%-0.83 wt.%）, Y （3.0 ppm-17.2 ppm）, and heavy rare-earth element （HREE） contents. This indicates that these rocks were most likely derived from the partial melting of a thickened lower crust. In situ zircon U-Pb dating of these granites yields Early Caledonian ages （437 Ma for biotite monzonitic granites and 424 Ma for alkali-feldspar granites）, indicating that the Huichizi granitic complex is the product of multi-periodic magmatism. The positive but varying zircon tHe（t） values （＋0.6 to ＋8.5） suggest that this thickened lower crust was mainly juvenile, i.e., accreted from depleted mantle during the Neo-Mesoproterozoic Period, but involved the ancient recycled crust. Biotite monzonitic granites formed during crust thickening at the extrusion stage, whereas the alkali granites formed during crust thickening at the extension stage （post extrusion）. The Huichizi granite complex witnessed the process of extrusion to extension because of the collision between the NCB and the Qinling microcontinent in the Caledonian.展开更多
Committed to obtaining cost-effective NdFeB based permanent magnets,Nd_(27-x)La_(3)Y_(x)Fe_(bal)Al_(0.1)Cu_(0.1)B_(1)(x=0-3)alloys were fabricated to detect the magnetic properties and microstructure.When x=1.8,coerci...Committed to obtaining cost-effective NdFeB based permanent magnets,Nd_(27-x)La_(3)Y_(x)Fe_(bal)Al_(0.1)Cu_(0.1)B_(1)(x=0-3)alloys were fabricated to detect the magnetic properties and microstructure.When x=1.8,coercivity of 1004 kA/m and the magnetic remanence of 0.75 T are obtained,which are close to those of the original Nd_(30)Fe_(bal)A_(l0.1)Cu_(0.1)B_(1)alloy ribbons.The temperature coefficient of coercivity(β)and the temperature coefficient of remanence(α)of the LaY-substituted alloys are better than those of the original alloys.The research results manifest that La is mainly distributed in the grain boundary phases and plays the role of refining the main grains,optimizing the grain boundary phases and improving the wettability between the main phases and the grain boundary phases,while Y tends to enrich in the main phases and enhances the short-range exchange coupling.展开更多
基金supported by the 973 Program(No.2014CB049000,2011CB610304)National Natural Science Foundation of China(11372062,91216201)+2 种基金LNET Program(LJQ2013005)China Postdoctoral Science Foundation(2014M551070)111Project(B14013)
文摘Commercially available lattices contain various kinds of morphological imperfections which result in great degradation in lattices＇ mechanical properties, therefore, to obtain imperfection insensitive lattice structure is obviously a practical research subject. Hierarchical structure materials were found to be a class of promising anti-defect materials, This paper builds hierarchical lattice by adding soft adhesion to lattice＇s cell edges and numerical results show that its imperfection sensitivity to missing bars is minor compared with the classic lattice. Soft adhesion with appropriate properties reinforce cell edge＇s bending stiffness and thus reduce the bending deformation in lattice caused by missing bars defect, which is confirmed by statistical analysis of normalized node displacements of imperfect lattices under hydrostatic compression and shear loads.
基金financially supported by the National Basic Research Program of China (No. 2014CB440906)the Strateic Priority Research Program (B) of Chinese Academy of Sciences (No. XDB18030200)the National Natural Sciences Foundation of China (Nos. 41473049, 41103027)
文摘The Huichizi granite complex is the largest Paleozoic 1-type intrusion located in the North Qinling orogenic belt （NQB）. In this study, we present systematic geochemical element data, zircon U-Pb ages, Ln-Hf isotopic data, and Sr-Nd isotopic data for the Huichizi granites. In terms of mineral and chemical compositions, these granites are biotite monzonitic and alkali-feldspar granites, both of which are characterized by high SiO2 and total alkali contents and low MgO, TiO2, and TFeO contents. These granites are weakly peraluminous （A/CNK values are 1-1.06 for biotite mon- zonitic granites and 1.04-1.09 for alkali-feldspar granites） and possess the geochemical characteristics of adakitic rocks, e.g., high Sr contents （319 ppm-633 ppm）, Sr/Y ratios （18.5-174）, and （La/Yb）N ratios （17.6-57） and low MgO （0.04 wt.%-0.83 wt.%）, Y （3.0 ppm-17.2 ppm）, and heavy rare-earth element （HREE） contents. This indicates that these rocks were most likely derived from the partial melting of a thickened lower crust. In situ zircon U-Pb dating of these granites yields Early Caledonian ages （437 Ma for biotite monzonitic granites and 424 Ma for alkali-feldspar granites）, indicating that the Huichizi granitic complex is the product of multi-periodic magmatism. The positive but varying zircon tHe（t） values （＋0.6 to ＋8.5） suggest that this thickened lower crust was mainly juvenile, i.e., accreted from depleted mantle during the Neo-Mesoproterozoic Period, but involved the ancient recycled crust. Biotite monzonitic granites formed during crust thickening at the extrusion stage, whereas the alkali granites formed during crust thickening at the extension stage （post extrusion）. The Huichizi granite complex witnessed the process of extrusion to extension because of the collision between the NCB and the Qinling microcontinent in the Caledonian.
基金Project supported by the National Natural Science Foundation of China(51901089,52061015)China Postdoctoral Science Foundation(2020M682064)+3 种基金Young Elite Scientists Sponsorship Program by CAST(YESS20200250)the Key Research and Development Program of Jiangxi Province(20201BBE51010)Postdoctoral Science Foundation of Jiangxi Province(2020KY19)the Program of Qingjiang Excellent Young Talents of Jiangxi University of Science and Technology(JXUSTQJYX2020003)。
文摘Committed to obtaining cost-effective NdFeB based permanent magnets,Nd_(27-x)La_(3)Y_(x)Fe_(bal)Al_(0.1)Cu_(0.1)B_(1)(x=0-3)alloys were fabricated to detect the magnetic properties and microstructure.When x=1.8,coercivity of 1004 kA/m and the magnetic remanence of 0.75 T are obtained,which are close to those of the original Nd_(30)Fe_(bal)A_(l0.1)Cu_(0.1)B_(1)alloy ribbons.The temperature coefficient of coercivity(β)and the temperature coefficient of remanence(α)of the LaY-substituted alloys are better than those of the original alloys.The research results manifest that La is mainly distributed in the grain boundary phases and plays the role of refining the main grains,optimizing the grain boundary phases and improving the wettability between the main phases and the grain boundary phases,while Y tends to enrich in the main phases and enhances the short-range exchange coupling.
