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利用碳纳米管固相萃取气相色谱法对水中有机氯农药和多氯联苯的测定 总被引:9,自引:2,他引:7
研究利用碳纳米管作为固定相,萃取水中4种有机氯农药(Heptachlor、 Aldrin、 Dieldrin、 Endrin)和5种多氯联苯(PCB052、 101、 138、 153、 180),并用GC/ECD测定.建立了碳纳米管柱SPE/GC/ECD同时测定水中4种有机氯农药和5种多氯联苯的分析方法.通过空白加标和样品基质加标实验考察了方法性能,测得碳纳米管柱萃取的方法检出限为0.10~0.27μg·L-1,相对标准偏差为8.61%~19.3%,9种目标化合物的回收率在62~0%之间. 相似文献
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Nong-Chao Xin 《中国物理 B》2021,30(11):113701-113701
Molecular dynamics simulation of a sympathetically-cooled 113Cd+ ion crystal system is achieved. Moreover, the relationship between ions' axial temperature and different electric parameters, including radio frequency voltage and end-cap voltage is depicted. Under stable trapping condition, optimum radio frequency voltage, corresponding to minimum temperature and the highest cooling efficiency, is obtained. The temperature is positively correlated with end-cap voltage. The relationship is also confirmed by a sympathetically-cooled 113Cd+ microwave clock. The pseudo-potential model is used to illustrate the relationship and influence mechanism. A reasonable index, indicating ions' temperature, is proposed to quickly estimate the relative ions' temperature. The investigation is helpful for ion crystal investigation, such as spatial configuration manipulation, sympathetic cooling efficiency enhancement, and temporal evolution. 相似文献
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研究偶数维空间带粘性的波动方程柯西问题解的逐点估计.通过对格林函数的精细分析,得到解的大时间状态.解呈现出惠更斯现象. 相似文献
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Rotational symmetry of classical orbits, arbitrary quantization of angular momentum and the role of the gauge field in two-dimensional space 下载免费PDF全文
We study quantum–classical correspondence in terms of the coherent wave functions of a charged particle in two- dimensional central-scalar potentials as well as the gauge field of a magnetic flux in the sense that the probability clouds of wave functions are well localized on classical orbits. For both closed and open classical orbits, the non-integer angular-momentum quantization with the level space of angular momentum being greater or less than is determined uniquely by the same rotational symmetry of classical orbits and probability clouds of coherent wave functions, which is not necessarily 2π-periodic. The gauge potential of a magnetic flux impenetrable to the particle cannot change the quantization rule but is able to shift the spectrum of canonical angular momentum by a flux-dependent value, which results in a common topological phase for all wave functions in the given model. The well-known quantum mechanical anyon model becomes a special case of the arbitrary quantization, where the classical orbits are 2π-periodic. 相似文献
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Effect of NaCl doped into Bphen layer on the performance of tandem organic light-emitting diodes 下载免费PDF全文
To improve the performance of tandem organic light-emitting diodes (OLEDs), we study the novel NaCl as n-type dopant in Bphen:NaCl layer. By analyzing their relevant energy levels and cartier transporting characteristics, we discuss the mechanisms of the effective charge generation layer (CGL) of Bphen:NaCl (6 wt%)/MoO3. In addition, we use the Bphen:NaC1 (20 wt%) layer as the electron injection layer (ELL) combining the CGL to further improve the performance of tandem device. For this tandem device, the maximal current efficiency of 9.32 cd/A and the maximal power efficiency of 1.93 lm/W are obtained, which are enhanced approximately by 2.1 and 1.1 times compared with those of the single- emissive-unit device respectively. We attribute this improvement to the increase of electron injection ability by introducing of Bphen:NaCl layer. Moreover, the CGL is almost completely transparent in the visible light region, which is also important to achieve an efficient tandem OLEDs. 相似文献
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