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从采自青藏高原阿汝和古里雅冰川的两支冰芯中选取31个样品,分别用三种仪器对比分析K^+、Na^+、Ca^2+、Mg^2+四种水溶金属离子,寻求最佳分析方案。分析结果对比发现,电感耦合等离子体发射光谱(ICP-OES)法在K+测量中存在困难,而离子色谱(IC)法和电感耦合等离子体质谱(ICP-MS)法均能够满足要求,且分析结果具有高度的一致性,四种离子的相关系数(R2)均在0.97以上,且并未出现ICP-MS法比IC法测量值明显偏高的现象。因此,除IC法外,ICP-MS法也是检测青藏高原雪冰样品中水溶金属离子的有效手段,其测定速度更快,且可以同时进行微、痕量元素检测,适用于大批量冰芯样品的快速分析。 相似文献
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Zhengliang Lu Yuanchao Zhao Baolian Chen Ximing Huang Chunhua Fan 《Acta Crystallographica. Section C, Structural Chemistry》2014,70(7):718-721
The title compound, [MnCl2(C24H20N6)], has been synthesized and characterized based on the multifunctional ligand 2,5‐bis(2,2′‐bipyridyl‐6‐yl)‐3,4‐diazahexa‐2,4‐diene (L). The MnII centre is five‐coordinate with an approximately square‐pyramidal geometry. The L ligand acts as a tridendate chelating ligand. The mononuclear molecules are bridged into a one‐dimensional chain by two C—H...Cl hydrogen bonds. These chains are assembled into a two‐dimensional layer through π–π stacking interactions between adjacent uncoordinated bipyridyl groups. Furthermore, a three‐dimensional supramolecular framework is attained through π–π stacking interactions between adjacent coordinated bipyridyl groups. 相似文献
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Lu Z Costa JS Roubeau O Mutikainen I Turpeinen U Teat SJ Gamez P Reedijk J 《Dalton transactions (Cambridge, England : 2003)》2008,(27):3567-3573
A new bifunctional, triazine-based ligand has been designed with the aim to generate a copper(II) complex holding a TEMPO (2,2,6,6-tetramethylpiperidinyloxy) moiety. The coordination compound obtained from the ligand 4-(2-(3-(pyridin-2-yl)-1H-pyrazol-1-yl)ethoxy)-6-(4-amino-2,2,6,6-tetramethylpiperidine-1-oxyl)-N,N-diphenyl-1,3,5-triazin-2-amine (pypzt-1) and copper(II) bromide (i.e. complex 8) is capable of catalysing the selective, aerobic oxidation of benzyl alcohol to 84% of benzaldehyde in 24 h. This "galactose oxidase activity" of the copper/TEMPO complex is observed as well for the conversion of the non-activated alkyl alcohol octan-1-ol to octanal with a yield of 29% after the same reaction time. The single-crystal X-ray structure of 8 shows that its crystal lattice contains [Cu(I)Br(2)](-) anions which appear to be stabilised by means of both anion-pi and hydrogen bonding interactions. In addition, the solid state structure of 8 exhibits (lone-pair)-pi interactions between the nitrogen atom of an acetonitrile molecule and a triazine ring. The magnetic properties of 8 have been investigated by EPR and magnetic susceptibility measurements. 相似文献
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利用不完全自锁模激光研究C60的反饱和吸收效应 总被引:2,自引:1,他引:2
本文报道首次采用色心晶体的不完全自锁模激光(1064nm)对C60分子反饱和吸收效应的研究,实验结果与采用平均过程的研究方法是一致的,文中还讨论了C60分子反饱和吸收效应产生的原因。 相似文献
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Zhengliang Liu Jinyu Jiao Ying Zheng 《中国颗粒学报》2006,4(3):204-210
The axial velocity distribution in a gas cyclone has been examined with two-dimensional particle image velocimetry (2D-PIV) and three-dimensional particle image velocimetry (3D-PIV) experiments in this study. Due to the limitation of 2D-PIV configuration, the contamination generated by the strong tangential velocity in the cyclone can be registered in the axial velocity detected by 2D-PIV. Efficient methods are proposed in this work to remove this contamination. The contamination-removed 2D-PIV data agree well with 3D-PIV results. The distributions of the axial velocity are also computed by the Reynolds stress model (RSM) and verified using the PIV experimental results. Reasonable agreements are obtained. 相似文献
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The axial velocity distribution in a gas cyclone has been examined with two-dimensional particle image velocimetry (2D-PIV) and three-dimensional particle image velocimetry (3D-PIV) experiments in this study. Due to the limitation of 2D-PIV configuration, the contamination generated by the strong tangential velocity in the cyclone can be registered in the axial velocity detected by 2D-PIV. Efficient methods are proposed in this work to remove this contamination. The contamination-removed 2D-PIV data agree well with 3D-PIV results. The distributions of the axial velocity are also computed by the Reynolds stress model (RSM) and verified using the PIV experimental results. Reasonable agreements are obtained. 相似文献
10.
We give a two sided estimate on the spectral gap for the Boltzmann measures μh on the circle. We prove that the spectral gap is greater than 1 for any and the spectral gap tends to the positive infinity as with speed . 相似文献