In this work,several key scaling laws of the quasi-static magnetic compression of field reversed configuration(FRC)plasma(Spencer et al 1983 Phys.Fluids 261564)are amended from a series of two-dimensional FRC MHD equi...In this work,several key scaling laws of the quasi-static magnetic compression of field reversed configuration(FRC)plasma(Spencer et al 1983 Phys.Fluids 261564)are amended from a series of two-dimensional FRC MHD equilibriums numerically obtained using the Grad–Shafranov equation solver NIMEQ.Based on the new scaling for the elongation and the magnetic fields at the separatrix and the wall,the empirically stable limits for the compression ratio,the fusion gain,and the neutron yield are evaluated,which may serve as a more accurate estimate for the upper ceiling of performance from the magnetic compression of FRC plasma as a potential fusion energy as well as neutron source devices.展开更多
Results from sediment trap experiments conducted in the southern South China Sea from May 2004 to March 2006 revealed significant monsoon-induced seasonal variations in flux and shell geochemistry of planktonic forami...Results from sediment trap experiments conducted in the southern South China Sea from May 2004 to March 2006 revealed significant monsoon-induced seasonal variations in flux and shell geochemistry of planktonic foraminifera. The total and species-specific fluxes showed bimodal pattern, such as those of Globigerinoides ruber, Globigerinoides sacculifer, Neoglobo-quadrina dutertrei, Globigerinita glutinata, and Globigerina bulloides. Their high values occurred in the prevailing periods of the northeast and southwest monsoons, and the low ones appeared between the monsoons. Pulleniatina obliquiloculata had high flux rates mainly during northeast monsoon, with exceptional appearance in August 2004. These fluxes changed largely in accord with those of total particle matter and organic carbon, following chlorophyll concentration and wind force. It is inferred that the biogenic particle fluxes are controlled essentially by primary productivity under the influence of East Asian monsoon in the southern SCS. Shell stable oxygen isotope and Mg/Ca data correspond with seasonal variation of sea surface temperature. Shell δ18O values are affected primarily by sea water temperature, and the δ18O changes of different-depth dwelling species indicate upper sea water temperature gradient. Besides, the low carbon isotope values occurred in the periods of East Asian monsoon in general, whereas the high ones between the monsoons. The pattern is in contrary to chlorophyll concentration change, which indicates that the variation of the carbon isotope could probably reflect the change of sea surface productivity.展开更多
基金supported by the National Magnetic Confinement Fusion Program of China (No. 2017YFE0301805)National Natural Science Foundation of China (No. 51821005)+3 种基金the Fundamental Research Funds for the Central Universities at Huazhong University of Science and Technology (No. 2019kfy XJJS193)the U.S. Department of Energy (Nos. DE-FG02-86ER53218 and DE-SC0018001)the supports from the NIMROD teamthe support from the Chinese Government Scholarship.
文摘In this work,several key scaling laws of the quasi-static magnetic compression of field reversed configuration(FRC)plasma(Spencer et al 1983 Phys.Fluids 261564)are amended from a series of two-dimensional FRC MHD equilibriums numerically obtained using the Grad–Shafranov equation solver NIMEQ.Based on the new scaling for the elongation and the magnetic fields at the separatrix and the wall,the empirically stable limits for the compression ratio,the fusion gain,and the neutron yield are evaluated,which may serve as a more accurate estimate for the upper ceiling of performance from the magnetic compression of FRC plasma as a potential fusion energy as well as neutron source devices.
基金supported by National Key Development Program for Fundamental Research (Grant No.2007CB815901)National Natural Science Foundation of China (Grant No.40621063)
文摘Results from sediment trap experiments conducted in the southern South China Sea from May 2004 to March 2006 revealed significant monsoon-induced seasonal variations in flux and shell geochemistry of planktonic foraminifera. The total and species-specific fluxes showed bimodal pattern, such as those of Globigerinoides ruber, Globigerinoides sacculifer, Neoglobo-quadrina dutertrei, Globigerinita glutinata, and Globigerina bulloides. Their high values occurred in the prevailing periods of the northeast and southwest monsoons, and the low ones appeared between the monsoons. Pulleniatina obliquiloculata had high flux rates mainly during northeast monsoon, with exceptional appearance in August 2004. These fluxes changed largely in accord with those of total particle matter and organic carbon, following chlorophyll concentration and wind force. It is inferred that the biogenic particle fluxes are controlled essentially by primary productivity under the influence of East Asian monsoon in the southern SCS. Shell stable oxygen isotope and Mg/Ca data correspond with seasonal variation of sea surface temperature. Shell δ18O values are affected primarily by sea water temperature, and the δ18O changes of different-depth dwelling species indicate upper sea water temperature gradient. Besides, the low carbon isotope values occurred in the periods of East Asian monsoon in general, whereas the high ones between the monsoons. The pattern is in contrary to chlorophyll concentration change, which indicates that the variation of the carbon isotope could probably reflect the change of sea surface productivity.
