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1.
In this work, a green technique for preparing TbFeO3/CuO was reported by employing Crataegus and Lantana Camara leaves as fuel and alkalizing agents, respectively. The new sensor based on the perovskite-type nanocomposite was employed as a sensitive and selective platform to detect Pb(II), Zn(II) and Cd(II) simultaneously. TbFeO3/CuO/Carbon paste electrode (CPE) exhibited a large specific surface area and great electrical conductivity, which enhanced electron transport in the electrochemical process considerably. Moreover, square wave anodic stripping voltammetry (SWASV) was used for the investigation of some factors influencing the sensor sensitivity like pH, modifier concentration, as well as accumulation time and potential. Therefore, the low detection limit (LOD) and a wide linear range were obtained at optimum conditions. In this study, a linear range between 0.9 and 110 µg/L for three ions and LOD of 0.48, 0.29 and 0.12 for zinc, cadmium and lead were achieved, respectively. Moreover, TbFeO3/CuO/CPE was employed to detect zinc, cadmium and lead ions simultaneously in the real samples so that the results have shown consistency with a standard inductively coupled plasma (ICP).  相似文献   
2.
重金属污染一直影响着人们的健康生活,如镉,铅和铜等的污染,故而土壤重金属的快速检测和如何预防,一直受各国学者关注和研究。传统土壤重金属检测方法(如原子吸收光谱法、X荧光光谱法等)样品预处理复杂,分析成本较高,易形成样品的二次污染,不能满足快速分析的要求。激光诱导击穿光谱(LIBS)是一种典型的原子发射光谱,它是基于分析物质中原子和离子受激发而发射的特征谱线信息,进而研究物质成分的分析方法。LIBS技术能够快速检测任何状态(固、液和气态)物质元素的成分和含量,被看作是未来化学检测和快速绿色分析领域的新兴技术。LIBS技术具有对样本简单预处理(或不需要处理)、多元素同步分析、远距离测量、适用性广等优势,被广泛用于生活生产的各个领域,已成为近年来国内外学者广泛关注和研究的热点之一。在农业信息快速感知的大背景下,以激光诱导击穿光谱技术为技术手段,以土壤重金属铅元素为研究对象,运用理论分析和数学建模相结合,建立了多种基于单变量定标曲线的土壤重金属铅检测模型,并进行了模型验证。自制15个已知的铅元素浓度梯度的谱线土壤样本,在获取了土壤LIBS数据之后,对其进行预处理对比,建立了基于谱峰强度、谱峰积分、洛伦兹拟合强度三种定标曲线模型,对土壤中铅元素含量进行定量分析,得出基于三种定标曲线模型对土壤中铅元素含量的预测决定系数R2分别为0.918 0,0.910 1和0.914 3,三种定标曲线分析方法的预测结果都较好,说明了LIBS结合单变量定标曲线法对土壤中铅含量的检测可靠性高。最后选取部分样本数据进行验证,结果较好。研究结果为研发便携式农田土壤污染物检测技术与装备提供技术支撑,也为农田精准管理和科学施肥奠定基础。  相似文献   
3.
The development of highly sensitive and selective methods for the detection of lead ion (Pb2+) is of great scientific importance. In this work, we develop a new surface‐enhanced Raman scattering (SERS)‐based sensor for the selective trace measurement of Pb2+. The SERS‐based sensor is assembled from gold nanoparticles (AuNPs) and graphene using cucurbit[7]uril (CB[7]) as a precise molecular glue and a local SERS reporter. Upon the addition of Pb2+, CB[7] forms stronger complexes with Pb2+ and desorbs from AuNPs, resulting in a sensitive “turn‐off” of SERS signals. This SERS‐based assay shows a limit of detection (LOD) of 0.3 nm and a linear detection range from 1 nm to 0.3 μm for Pb2+. The feasibility of the assay is further demonstrated by probing Pb2+ in real water samples. This SERS‐based analytical method is highly sensitive and selective, and therefore holds promising applications in environmental analysis.  相似文献   
4.
粗二氧化碲作为碲精炼或碲化工产品生产的重要原料,其中共存元素铜、铅、砷、锑、铋、硒含量的准确测定对于生产过程质量控制和贸易结算具有重要意义,但目前没有粗二氧化碲中铜、铅、砷、锑、铋、硒含量检测的标准分析方法。采用王水和饱和氟化氢铵分解试样,在王水和酒石酸介质中,选用Cu 327.393 nm、Pb 220.353 nm、Sb 217.582 nm、Bi 223.061 nm、As 193.696 nm、Se 196.026 nm为分析谱线,采用电感耦合等离子体发射光谱(ICP-AES)法测定粗二氧化碲中铜、铅、锑、铋、砷和硒含量。各元素校准曲线的相关系数均大于0.999;铜、铅、锑、铋、砷和硒的检出限分别为0.0004%、0.0005%、0.0006%、0.0007%、0.0004%和0.0007%,定量检出限分别为0.0012%、0.0016%、0.0020%、0.0025%、0.0013%和0.0025%。按照实验方法测定5个粗二氧化碲样品中铜、铅、锑、铋、砷和硒,测定结果的相对标准偏差(RSD,n=7)为0.79%~4.8%,加标回收率为96.0%~103%。方法简单,精密度和准确度较高,可用于测定粗二氧化碲中铜、铅、砷、锑、铋、硒含量。  相似文献   
5.
A zircon U–Pb dating method with a high spatial resolution of 2- to 3-μm was successfully implemented by using Cameca IMS-1280HR SIMS in this study. Homemade cathode and modified intermediate pole were used to improve the intrinsic performance of duoplasmatron ion source. An O primary beam with intensity of approximately 3 μA and stability of 0.68% over 40 minutes was achieved and could be used continuously for more than 240 hours under high current conditions. Under Gaussian illumination mode, a 2- to 3-μm O primary beam was obtained with an intensity of approximately 200 pA. Four standard zircons, namely, 91500, Temora, Plešovice, and Qinghu, were dated using the 2- to 3-μm high spatial resolution U–Pb isotopic analysis, yielding U–Pb ages consistent with their recommended values, within errors. Our work shows that zircon U–Pb dating with high accuracy and spatial resolution can be achieved, on the basis of a series of duoplasmatron modification and instrumental optimization.  相似文献   
6.
李敏  时鑫娜  张泽霖  吉彦达  樊济宇  杨浩 《物理学报》2019,68(8):87302-087302
随着柔性电子产品的迅速发展,具有优异铁电和压电性的Pb(Zr_(0.53)Ti_(0.47))O_3 (PZT)薄膜在柔性的非易失性存储器、传感器和制动器等器件中有广泛的应用前景.同时,由于外部环境越来越复杂,具有高温稳定特性的材料和器件受到越来越多的关注.本文在耐高温的二维层状氟晶云母衬底上,用脉冲激光沉积技术制备出外延的PZT薄膜,并通过机械剥离的方法,得到柔性的外延PZT薄膜.研究了Pt/PZT/SRO异质结的铁电和压电性及其高温特性,发现样品表现出优越的铁电性,剩余极化强度(P_r)高达65μC/cm~2,在弯曲104次后其铁电性基本保持不变,且样品在275℃高温时仍然保持良好的铁电性.本文为柔性PZT薄膜在航空航天器件中的应用提供了实验基础.  相似文献   
7.
采用硝酸、盐酸、氢氟酸、高氯酸分解样品,氢溴酸-盐酸挥发消除砷基体,优化仪器测定参数,选取最佳工作条件,建立了电感耦合等离子体原子发射光谱(ICP-AES)法测定铜砷滤饼中Pb、Fe、Bi元素的分析方法。其测定范围为:ω(Pb):0.12%~2.09%;ω(Fe):0.081%~2.10%;ω(Bi):1.20%~6.14%。各元素检出限为Pb:0.010μg/mL;Bi:0.006μg/mL;Fe:0.003μg/mL。加标回收率为95.5%~101.7%。该方法简便,准确,可靠,适用于铜砷滤饼中Pb、Fe、Bi元素的同时测定。  相似文献   
8.
The thermophysical properties of low‐temperature Pb plasma are calculated at temperatures 10–100 kK and densities below 0.2 of the solid‐state value. The thermodynamic values (pressure and internal energy) and transport coefficients (electrical conductivity, thermal conductivity, and thermal power) are considered. The plasma composition and thermodynamic parameters are obtained within the chemical approach, namely by means of the solution of the corresponding system of the coupled mass action law equations. Atom ionization up to +4 is taken into consideration. The electronic transport coefficients are calculated within the relaxation time approximation. The results obtained by means of the present model are compared with the available data of other models and experiments.  相似文献   
9.
以ABS塑料为研究对象,采用微波消解法进行样品的前处理,使用电感耦合等离子体发射光谱法测定ABS塑料中Pb、Cd、Hg,结果表明,Pb、Cd、Hg加标回收率均在95~105%之间,测试精密度均小于3%,该方法在缩短样品前处理时间的同时得到较高的元素消解回收率和较为理想的精确度,适用于ABS塑料中重金属含量的快速测定。  相似文献   
10.
In this study, multiwalled carbon nanotube (MWCNT) was modified by the pyridine group using a silane agent and characterized by infrared spectroscopy (IR), thermal analysis (TG/DTA), and elemental analysis (CHN) and scanning electron microscopy (SEM). The application of this sorbent was investigated in determination of lead ions in aqueous samples, using flame atomic absorption spectrometry (FAAS). Through this study, different parameters such as pH and sample flow rate on adsorption process and eluent concentration, volume and flow rate were optimized. The limit of detection (LOD), the relative standard deviation and the recovery of the method were 2 ng mL?1, 1.3% and 99.7%, respectively. Two standard reference materials (NIST 1571 and NIST 1572) were used to verify accuracy of this method. Finally, the sorbent was successfully applied for extraction and determination of low levels of Pb(II) ions in aqueous samples.  相似文献   
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