原子吸收测定土壤镍的测量不确定度评定研究   总被引：2，自引：0，他引：2  

王如海  蒋倩  朱小芳  王曦  钱薇  龚华  倪俊  韩勇  俞元春 《土壤》2014,46(1):139-144

本文评定了火焰原子吸收测定土壤中镍含量的测量不确定度。以标准土壤样品(GSW 17401)为测试对象,通过应用火焰原子吸收法测定土壤镍含量,对其测量不确定度的来源、计算和结果表示等问题进行探讨。样品消解前处理产生的不确定度最大,标准曲线拟合测定溶液产生的不确定度其次。在测定中前处理和标准曲线拟合测定溶液应给予足够重视,以减小测量不确定度。  相似文献   

Greenhouse evaluation of EDTA effectiveness at enhancing Cd,Cr, and Ni uptake in <Emphasis Type="Italic">Helianthus annuus</Emphasis> and <Emphasis Type="Italic">Thlaspi caerulescens</Emphasis>     

Jeffrey Munn  Mary January  Teresa J. Cutright 《Journal of Soils and Sediments》2008,8(2):116-122

Background, Aims and Scope  Phytoremediation is a promising means for the treatment of heavy metal contamination. Although several species have been identified as hyperaccumulators, most studies have been conducted with only one metal. Experiments were conducted to investigate the ability of Helianthus annuus and Thlaspi caerulescens to simultaneously uptake Cd, Cr and Ni. Materials and Methods  The efficiency of plants grown in a sandy-loam soil was investigated. The ability of two EDTA concentrations (0.1 and 0.3 g kg⁻¹) for enhancing the phytoremediation of Cd, Cr and Ni at two different metal concentrations (24.75 mg kg⁻¹ and 90 mg kg⁻¹) was studied. Results   Thlaspi hyperaccumulated Ni with 0.1 g kg⁻¹ EDTA. When the EDTA dosage was increased to 0.3 g kg⁻¹, Thlaspi was able to hyperaccumulate both Ni and Cr. Since Thlaspi is a low-biomass plant, it was considered insufficient for full-scale applications. Helianthus annuus hyperacummulated Cr (with 0.1 g kg⁻¹ EDTA) and Cd (0.3 g kg⁻¹ EDTA). Discussion  When the contamination was 8.25 mg kg⁻¹ per metal, the total metal uptake was 10–25% (1.35 to 2.12 mg) higher and had the same uptake selectivity (Cr>>Cd>Ni) for both EDTA levels. It was hypothesized that complexation with EDTA interfered with Ni translocation. For these experiments, the optimal results were obtained with the H. annuus-0.1 g kg⁻¹ EDTA combination. Conclusions  Although the use of EDTA did increase the amount of metal that could be extracted, care should be taken during in-situ field applications. Chelators can also increase the amount of metals that are leached past the root zone. Metal leaching and subsequent migration could lead to ground water contamination as well as lead to new soil contamination. Recommendations and Perspectives  Additional research to identify the optimal EDTA dosage for field applications is warranted. This is necessary to ensure that the metals do not leach past the root zone. Identification of a plant that can hyperaccumulate multiple metals is critical for phytoremediation to be a viable remediation alternative. In addition to being able to hyperaccumulate multiple metals, the optimal plant must be fast growing with sufficient biomass to sequester the heavy metals.  相似文献   

逸人·逸笔·逸气——论倪瓒诗画创作风格的互通          下载免费PDF全文

戴欢欢  任声楠 《安徽农业大学学报》2021,30(2):114-118

倪瓒身处元末，散尽家财，隐迹山水，交游甚广，以写诗、作画以自娱。倪瓒之画，不求形似，简笔率略而成，自得天真逸趣，形成简远空疏之境。倪瓒之诗，不事雕琢，遇事感兴，得乎性情之正，有冲淡萧散之风。作为画家兼诗人，倪瓒打破了画与诗两种不同艺术形式之间的壁垒，实现了其诗画艺术风格的互通。  相似文献