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Spline finite strip has been successfully applied in solving right plates and shells by Cheung et al in 1982. In this paper, the method is extended to the analysis of parallelogram plate. This extension still retains the banded nature of the spline finite strip and only small amount of extra computing effort is required. Further-more, the discretisation error of the above method is established theoretically as a general case for the spline finite strip method. 相似文献
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建立了固相萃取(SPE)与气相色谱质谱(GC-MS)联用测定自然水体中8种有机磷酸酯阻燃剂(OPFRs)OPFRs的分析方法。通过对GC MS条件与SPE萃取条件的优化,采用Poly-Sery PSD固相萃取小柱对水样进行富集浓缩,用4 mL乙酸乙酯洗脱,以选择离子扫描方式对目标物进行定性和定量分析,并采用内标法定量。本方法在对应OPFRs线性范围内的线性相关系数为0.9937~0.9995;检出限为0.006~0.850 ng/L;定量限为0.015~2.0 ng/L。除磷酸三(2-乙基)己基酯(TEHP)外,其它OPFRs的加标回收率为70.3%~114.3%。TEHP加标10和50 ng/L时,回收率为64.0%~69.3%;加标100 ng/L时回收率为34.3%。将本方法应用于太湖梅梁湾水体中OPFRs分析,其总浓度值为1000~2700 ng/L。 相似文献
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Spline finite strip has been successfully applied in solving right plates and shells by Cheung et al in 1982. In this paper, the method is extended to the analysis of parallelogram plate. This extension still retains the banded nature of the spline finite strip and only small amount of extra computing effort is required. Furthermore, the discretisation error of the above method is established theoretically as a general case for the spline finite strip method. 相似文献
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固相微萃取气相色谱法(SPME-GC)测定水体中邻苯二甲酸酯 总被引:9,自引:0,他引:9
选用85μm PA纤维,考证了萃取温度、萃取时间、搅拌、离子强度及解析时间等影响因素,最后确立了65℃萃取温度、60min萃取时间、稳定的磁力搅拌、5min解析时间、用带电子捕获检测器的毛细管气相色谱(CGC—ECD)分离测定、外标标准曲线法定量分析水体中邻苯二甲酸酯(PAEs)的方法。该方法具有较好的精密度(RSD≤16%)和较低的检出限(DLDBP=0.003μg/L,DLDEDEHP=0.05μg/L),水样加标回收率在70%~130%之间。用该法测定了长江水样、太湖水样、自来水及蒸馏水的PAEs含量,DBP在0.1~0.4μg/L,DEHP在0.2~1.2μg/L,DMP、DEP、DOP均未检测到。 相似文献
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浊点萃取在环境有机分析中的影响因素及应用 总被引:2,自引:0,他引:2
对近5年来浊点萃取技术在环境有机污染物分析中的进展作了综述,特别叙述了分析过程中的影响因素、与色谱的联用技术及其在环境分析中的应用,对此方法的原理也作了简要介绍(引述文献56篇). 相似文献
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高效液相色谱-荧光检测法同时测定蔬菜中3种磺胺类药物残留 总被引:2,自引:0,他引:2
建立了蔬菜中3种磺胺类药物(SAs)的高效液相色谱-荧光检测法。蔬菜样品用甲醇提取3次,将提取液浓缩干,用0.1mol/LHCl溶解残渣,经荧光胺衍生化后,用反相柱(ODS)分离,以乙腈和0.5%醋酸为流动相进行梯度洗脱,用荧光检测器检测。3种SAs的检出限(LOD)为1.02~1.29μg/g,方法的定量限(LOQ)为3.4~4.3ng/g(鲜重)。蔬菜样品中SAs的添加浓度在0.2~1.0ng/g范围内,3种SAs的平均回收率均大于87%,日内与日间RSD均小于10%。实际蔬菜样品测定结果表明,3种SAs在不同蔬菜中均有不同程度检出,总含量为0.0726~0.3709μg/g(鲜重)。 相似文献
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Unusual quadratic dispersion of flexural vibrational mode and red-shift of Raman shift of in-plane mode with increasing layer-number are quite common and interesting in low-dimensional materials, but their physical origins still remain open questions. Combining ab initio density functional theory calculations with the empirical force-constant model, we study the lattice dynamics of two typical two-dimensional(2 D) systems, few-layer h-BN and indium iodide(In I). We found that the unusual quadratic dispersion of flexural mode frequency on wave vector may be comprehended based on the competition between atomic interactions of different neighbors. Long-range interaction plays an essential role in determining the dynamic stability of the 2 D systems. The frequency red-shift of in-plane Raman-active mode from monolayer to bulk arises mainly from the reduced long-range interaction due to the increasing screening effect. 相似文献