Based on the frequency domain training sequences, the polynomial-based carrier frequency offset (CFO) estimation in multiple-input multiple-output ( MIMO ) orthogonal frequency division multiplexing ( OFDM ) sys...Based on the frequency domain training sequences, the polynomial-based carrier frequency offset (CFO) estimation in multiple-input multiple-output ( MIMO ) orthogonal frequency division multiplexing ( OFDM ) systems is extensively investigated. By designing the training sequences to meet certain conditions and exploiting the Hermitian and real symmetric properties of the corresponding matrices, it is found that the roots of the polynomials corresponding to the cost functions are pairwise and that both meger CFO and fractional CFO can be estimated by the direct polynomial rooting approach. By analyzing the polynomials corresponding to the cost functions and their derivatives, it is shown that they have a common polynomial factor and the former can be expressed in a quadratic form of the common polynomial factor. Analytical results further reveal that the derivative polynomial rooting approach is equivalent to the direct one in estimation at the same signal-to-noise ratio(SNR) value and that the latter is superior to the former in complexity. Simulation results agree well with analytical results.展开更多
An oxygen pressure leaching-flotation joint process was proposed to treat Jinbaoshan platinum group minerals to produce a desired concentrate. The result demonstrates that leaching parameters which include particle si...An oxygen pressure leaching-flotation joint process was proposed to treat Jinbaoshan platinum group minerals to produce a desired concentrate. The result demonstrates that leaching parameters which include particle size, stirring speed, liquid-solid ratio, and the dosage of calcium lignosulfonate, simultaneously affect the leaching rates of base metals and the recovery of platinum group metals (PGMs). The complete dissolution of base metals sulfides leads to a reduction in the amount of flotation carrier for enriching PGMs, decreasing the recovery of PGMs. The optimum leaching conditions are determined as follows: liquid-solid ratio of 10 mL/g, 73% occupancy of ore particle size below 0.043 mm, stirring speed of 400 r/min, and 0.6 g dosage of calcium lignosulfonate. Under optimal conditions, the leaching rates of Cu, Ni and Fe are 87.6%, 87.6% and 90.3%, respectively. The grade of PGMs enriched in the flotation concentrate is 420 g/t through the flotation technology.展开更多
The influence of different poly(ethylene glycol) alkyl ethers(CnH2n+1O(C2H4O)mH, CnEm) on flotation of carbonaceous copper shale mixed with quartz as a gangue mineral was investigated. The results show that all...The influence of different poly(ethylene glycol) alkyl ethers(CnH2n+1O(C2H4O)mH, CnEm) on flotation of carbonaceous copper shale mixed with quartz as a gangue mineral was investigated. The results show that all of the ethers C4E1, C4E2, C4E3, C2E2, C6E2 investigated can be used for the flotation of carbonaceous copper shale. The best selectivity of separation in the flotation of the carbonaceous copper shale and quartz mixture is obtained with the C4E2 and C2E2 ethers. The obtained data can be used for developing separation of organic carbon present in carbonaceous shale at a rougher flotation stage on an industrial scale.展开更多
基金The National Natural Science Foundation of China(No.60702028)the National High Technology Research and Development Program of China(863Program)(No.2007AA01Z268)
文摘Based on the frequency domain training sequences, the polynomial-based carrier frequency offset (CFO) estimation in multiple-input multiple-output ( MIMO ) orthogonal frequency division multiplexing ( OFDM ) systems is extensively investigated. By designing the training sequences to meet certain conditions and exploiting the Hermitian and real symmetric properties of the corresponding matrices, it is found that the roots of the polynomials corresponding to the cost functions are pairwise and that both meger CFO and fractional CFO can be estimated by the direct polynomial rooting approach. By analyzing the polynomials corresponding to the cost functions and their derivatives, it is shown that they have a common polynomial factor and the former can be expressed in a quadratic form of the common polynomial factor. Analytical results further reveal that the derivative polynomial rooting approach is equivalent to the direct one in estimation at the same signal-to-noise ratio(SNR) value and that the latter is superior to the former in complexity. Simulation results agree well with analytical results.
基金Projects(51804083,51204060) supported by the National Natural Science Foundation of ChinaProject(2017B090907026) supported by Science and Technology Planning Project of Guangdong Province,ChinaProjects(2018GDASCX-0938,2018GDASCX-0939) supported by Guangdong Academy of Science Doctor Special Program,China
文摘An oxygen pressure leaching-flotation joint process was proposed to treat Jinbaoshan platinum group minerals to produce a desired concentrate. The result demonstrates that leaching parameters which include particle size, stirring speed, liquid-solid ratio, and the dosage of calcium lignosulfonate, simultaneously affect the leaching rates of base metals and the recovery of platinum group metals (PGMs). The complete dissolution of base metals sulfides leads to a reduction in the amount of flotation carrier for enriching PGMs, decreasing the recovery of PGMs. The optimum leaching conditions are determined as follows: liquid-solid ratio of 10 mL/g, 73% occupancy of ore particle size below 0.043 mm, stirring speed of 400 r/min, and 0.6 g dosage of calcium lignosulfonate. Under optimal conditions, the leaching rates of Cu, Ni and Fe are 87.6%, 87.6% and 90.3%, respectively. The grade of PGMs enriched in the flotation concentrate is 420 g/t through the flotation technology.
基金support by the National Science Centre Research Grant (2012/07/D/ST8/02622)a fellowships financed by the Foundation for Polish Science (FNP)the European Union within the European Social Fund
文摘The influence of different poly(ethylene glycol) alkyl ethers(CnH2n+1O(C2H4O)mH, CnEm) on flotation of carbonaceous copper shale mixed with quartz as a gangue mineral was investigated. The results show that all of the ethers C4E1, C4E2, C4E3, C2E2, C6E2 investigated can be used for the flotation of carbonaceous copper shale. The best selectivity of separation in the flotation of the carbonaceous copper shale and quartz mixture is obtained with the C4E2 and C2E2 ethers. The obtained data can be used for developing separation of organic carbon present in carbonaceous shale at a rougher flotation stage on an industrial scale.