排序方式: 共有33条查询结果,搜索用时 15 毫秒
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ICP-AES同时测定水产品中的稀土元素 总被引:1,自引:0,他引:1
研究了 P50 7萃淋树脂预富集分离样品 ,试液用 ICP- AES法同时测定水产品中稀土元素 La、Sm、Y、Nd的新方法。在选定的最佳条件下测 La、Sm、Y、Nd的检出限分别为 0 .0 0 5 2、0 .0 0 70、0 .0 0 93、0 .0 16 1μg·m L-1,回收率为 93.4 %— 10 2 .5 % ,RSD为 1.3%— 3.6 %。该法准确、快速、简便 ,应用于水产品的测定 ,结果满意 相似文献
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天然水中微量稀土元素镧的流动注射在线预浓集ICP光谱法测定 总被引:1,自引:0,他引:1
本文采用P507萃淋树脂为固定相,应用流动注射(FI)在线预浓集技术,建立了镧的ICP发射光谱分析方法,对天然水中的微量镧进行了测定,获得满意结果。 相似文献
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化学光谱法测定5N氧化钆中14个稀土杂质元素 总被引:2,自引:0,他引:2
报道了化学光谱法测定5N高纯氧化钆中14个稀土杂质元素,在P507萃淋树脂色层柱上分离氧化钆中稀土杂质元素,分别采用定量分离La-Sm及Tb-Lu+Y和部份分离Eu的方法,并相应地采用碳粉吸附法和碳粉粉末法进行光谱测定。分离时间为3.5h,测定下限为1.2μg/g(RE)。 相似文献
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The microwave spectrum of isopropyl fluoroformate is characterized by intense a-type R-branch transitions from one conformational species. The rotational constants of the ground state, A0 = 4967.0(8) MHz, B0 = 1704.69(2) MHz, C0 = 1468.86(1) MHz and κ = −0.8651(2) are consistent with a τ1 (O=COC) = 0°, τ2(COCH) ˜35° structure. This structure can be viewed as a combination of the two conformational species found in ethyl fluoroformate. Two vibrational satellites having rotational constants A0 = 4963(5) MHz, B0 = 1694.11(7) MHz. C0 = 1471.43(4) MHz and A0=4998(6) MHz, B0 = 1705.21(7) MHz, C0 = 1471.10(4) MHz have been assigned. 相似文献
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Coupled transport of Eu(III) ions through a bulk liquid membrane containing mono(2-ethylhexyl)2-ethylhexyl phosphonate [HEH(EHP)] in kerosene has been examined. The influences of the carrier concentration, the HCl concentration in the stripping solution, the pH in the feed solution and the temperature were investigated. The transport of the Eu(III) ions is coupled by counter-transport of protons. The kinetics of the Eu(III) transport could be analyzed in the formalism of two consecutive irreversible first order reactions. The pseudo-first order apparent rate constants of the interfacial transport of the Eu(III) species are determined, varying temperature. The activation energy values are 14.0±1.0 and 54.0±3.4 kJ mol−1 for extraction and stripping, respectively. 相似文献
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The paper reports the results of an experimental study on pressure drop during horizontal flow boiling of refrigerants R22, R507, R404A, R134a, R407C and R410A. The test section is a smooth, horizontal, stainless steel tube (6 mm I.D., 6 m length) uniformly heated by Joule effect. The experimental tests are carried out at an almost constant evaporating pressure of 7.0 bar varying the mass flow rate in the range 280–1,080 kg/m2 s. The experimental comparison clearly shown that the pressure drop of R22 is significantly higher as compared to all the other fluids. The results are compared against well-known pressure drop prediction methods. The available correlations can be used for both pure fluids and mixtures with no corrective factors, provided the mixture properties are evaluated at local compositions. The Chawla friction correlation is the best-fitting of our experimental data in combination with the heterogeneous momentum pressure drop model on the basis of the Rouhani-Axelsson void fraction correlation. 相似文献