排序方式: 共有57条查询结果,搜索用时 15 毫秒
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本文讨论带梯度障碍的抛物型变分不等式解的存在性、唯一性和正则性问题.通过证明一类带梯度障碍的问题的求解等价于解某个双边障碍的问题,并利用双边障碍问题解的存在性、唯一性和正则性,得到了带梯度障碍的问题的相应结果.这一方法将有助于对具有梯度约束的非线性以及完全非线性抛物型方程解的正则性的研究. 相似文献
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Electrical spin polarization through spin-momentum locking in topological-insulator nanostructures 下载免费PDF全文
Recently, spin-momentum-locked topological surface states(SSs) have attracted significant attention in spintronics.Owing to spin-momentum locking, the direction of the spin is locked at right angles with respect to the carrier momentum.In this paper, we briefly review the exotic transport properties induced by topological SSs in topological-insulator(TI)nanostructures, which have larger surface-to-volume ratios than those of bulk TI materials. We discuss the electrical spin generation in TIs and its effect on the transport properties. A current flow can generate a pure in-plane spin polarization on the surface, leading to a current-direction-dependent magnetoresistance in spin valve devices based on TI nanostructures.A relative momentum shift of two coupled topological SSs also generates net spin polarization and induces an in-plane anisotropic negative magnetoresistance. Therefore, the spin-momentum locking can enable the broad tuning of the spin transport properties of topological devices for spintronic applications. 相似文献
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本文研究多组变量相关分析SSQCOR.准则的数值方法.从KKT条件出发引入了Gauss-Seidel型方法,从SSQCOR出发引入了交替变量法.证明了前者是后者的非精确形式,都具有单调上升性.为了提高得到全局解的可能性,引入了初始点策略.用实际数据和模拟数据进行了数值试验以说明算法的有效性. 相似文献
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Room-temperature ferromagnetism observed in Nd-doped In_2O_3 dilute magnetic semiconducting nanowires 下载免费PDF全文
Nd-doped In_2O_3 nanowires were fabricated by an Au-catalyzed chemical vapor deposition method.Nd atoms were successfully doped into the In_2O_3 host lattice structure,as revealed by energy dispersive x-ray spectroscopy,x-ray photoelectron spectroscopy,Raman spectroscopy,and x-ray diffraction.Robust room temperature ferromagnetism was observed in Nd-doped In_2O_3 nanowires,which was attributed to the long-range-mediated magnetization among Nd~(3+)-vacancy complexes through percolation-bound magnetic polarons. 相似文献
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原子吸收光谱法测定化妆品中铅、镉、铬、锌、铜和锰 总被引:1,自引:0,他引:1
重金属的危害越来越受到关注,它可以对动物体许多重要器官和神经系统造成损害甚至引发癌症和胎儿畸形。人们以前把主要注意力放在土壤、水和空气等经常直接或间接接触的污染源上。随着生活水平的提高,美容化妆已成为人们生活的一部分。目前化妆品不合格的报道经常出现,如含有重金属铬及其他致癌物质等。在化妆品卫生标准中,只列出对铅、汞和砷等元素的检测,一些化妆品中不仅含有上述元素,同时也含有镉、铬、 相似文献
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流动注射化学发光法测定间苯二酚 总被引:2,自引:0,他引:2
在碱性条件下,铁氰化钾氧化鲁米诺产生化学发光,间苯二酚对这一体系的化学发光具有很强的抑制作用.据此,结合流动注射技术,建立了一种测定间苯二酚的方法.线性范围为1.0×10-7~1.0×10-5mol·L-1;检出限(3σ)为2.0×10-8mol·L-1.该方法用于环境水样和皮炎宁酊中间苯二酚的测定,测定值的相对标准偏差(n=7)在1.9%~2.1%之间,其回收率在98.8%~103.0%之间. 相似文献
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