首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 78 毫秒
1.
建立了一个焊尘中铁,镍,锰的测定方法,优化了仪器工作参数,在优化后的条件下,铁,镍,锰三个元素的灵敏度分别为0.04μg/mL/1%,0.04μg/mL/1%,0.02μg/mL/1%。线性范围分别为铁0.1-10μg/mL,镍0.01-2μg/mL,锰0.05-5μg/mL。该方法回收率大于92%,用此方法成功地测定了焊尘中三元素的含量。  相似文献   

2.
火焰原子吸收法同时测定地质样品中金和银   总被引:2,自引:0,他引:2  
二氯化锡还原,二氯化汞共沉淀,火焰原子吸收法同时测定地质样品中金和银。对于原矿和尾矿样品,金含量为5.15μg/g,4.45μg/g和0.54μg/g时,相对标准偏差分别为6.2%,3.4%和4.1%。银含量为9.78μg/g和1.22μg/g时,相对标准偏差分别为4.4%,3.5%和12.5%。金的分析结果与参考值基本一致。金和银的回收率分别为88-102%和85-100%。方法具有干扰小,分离  相似文献   

3.
导数光谱法同时测定甲硝唑和维生素B6的研究   总被引:7,自引:0,他引:7  
本建立了以0.1mol/LHCl为介质,采用三阶导数光谱法,同时测定甲硝唑和维生素B6的新方法,方法检测限为0.81μg/mL甲硝唑和0.16μg/mL维生素B6,二测定的线性范围均为1.6-22.4μg/mL,直接用于复方甲硝唑片剂中甲硝唑和维生素B6的测定,两种生物的测定变异系数分别小于2.26和2.60%,回收率分别为93-102%和99-101%.  相似文献   

4.
火焰原子吸收法测定钢铁中铅,采用0.2%十二烷基硫酸钠和0.001mol/L硝酸介质,加入硫脲消除共存元铋的干扰,铅的浓度在0-20μg/mL范围内服从比耳定律。方法检出限为0.10μg/mL,相对标准偏差为2.30%,回收率97%-99%,样品测定结果令人满意。并对阴离子表面活性剂增感机理进行了探讨。  相似文献   

5.
萃取—火焰原子吸收法测定骨骼中的微量元素Cu,Zn,Cd和Fe   总被引:9,自引:0,他引:9  
本文研究了以邻菲罗啉为金属螯合剂,高氯酸钠为配体,在一定酸度下用1,2-二氯乙烷萃取-火焰原子吸收法测定动物骨骼中微量Cu,Zn,Cd和Fe的条件,并确定了测定方法,方法简单,准确,可靠,元素的检测限分别为:Cu:0.038μg/ml,Zn:0.0042μg/ml,Cd:0.0019μg/ml,Fe:0.02μg/ml,回收率在92.8%~105%之间。  相似文献   

6.
原子吸收光谱法间接测定钒的研究   总被引:3,自引:1,他引:2  
使V置换出N-亚硝基苯胲铜中的铜,原子吸收光谱法测定铜,间接测定钒,灵敏度为0.06μg/ml1%,直线范围0-8μg/ml,应用实际样品的分析,结果良好。  相似文献   

7.
本文叙述了痕量铍在铝合金中的重要作用以及石墨炉原子吸收光谱法测定铝合金中痕量铍的方法研究。该方法用硝酸(1+1)溶解样品。0.10mg/mL以上的铝具有增感效应,铍在0-0.25μg/100mL的范围内具有良好线性关系。该方法操作简便、灵敏度高,特征浓度为1.05×10 ̄(-5)μg/mL/1%。相对标准偏差为1.66%,回收率在96%-102.5%。  相似文献   

8.
平台石墨炉原子吸收法测定高温镍基合金中痕量碲   总被引:3,自引:0,他引:3  
用镍作基体改进剂,碲的灵敏度提高的约2倍,灰化温度提高400℃,抗干扰能力明显增强,不需要分离样品基体,采用平台石墨炉即可同温镍基金中痕量磅。方法检出限为0.041μg/g,样品中碲含量为0.5μg/g时,相对标准偏差为3-6%,回收率在90-99%之间,方法简单快速。  相似文献   

9.
火焰原子吸收光谱法连续测定茶叶中的锌、铜和锰   总被引:16,自引:0,他引:16  
本文研究了茶叶中锌、铜、锰微量金属元素的火焰原子吸收分光光度法的测定。方法简便、快速,灵敏度和精密度高,特征浓度锌为0.009μg/mL/1%,铜为0.031μg/mL/1%,锰为0.017μg/mL/1%;相对标准偏差为0.9%~5.0%,回收率92.0%~106.0%。  相似文献   

10.
铕的时间分辨激光荧光光谱分析:Ⅰ方法研究   总被引:2,自引:0,他引:2  
本工作是在自建装置上,利用时间分辨激光荧光光谱技术,选择Eu-TTA-EtOH液体荧光体系,建立了时间分辨激光荧光测定铕的方法。该测定铕离子的线性范围为0.0002-10μg/ml检测限为10^-5μg/ml。0.03μg/mlEu^3+标准样品EuTTA3,测定的相对标准偏差为4.7%,该法用于实际样品的分析测定,结果满意。结合铕的分析,对本方法选择化学体系的条件、测定装置的参数进行了讨论。并获  相似文献   

11.
陈辉林 《物理实验》2002,22(8):26-27
探讨在现行电子类实验教学大纲下的验证性实验如何与实际电子制作相结合,使学生由被动实验转为主动实验。通过制作发现问题、分析问题并解决问题,进一步巩固和加深对相关理论的理解,培养学生的实践能力。  相似文献   

12.
Serial transmission electron microscopy of human megakaryocytes (MKs) revealed their polyploidization and gradual maturation through consecutive transition in characteristics of various organelles and others. At the beginning of differentiation, MK with ploidy 32N, e.g., has 16 centrosomes in the cell center surrounded by 32N nucleus. Each bundle of microtubules (MTs) emanated from the respective centrosome supports and organizes 16 equally volumed cytoplasmic compartments which together compose one single 32N MK. During the differentiation, single centriole separated from the centriole pair, i.e., centrosome, migrates to the most periphery of the cell through MT bundle, corresponding to a half of the interphase array originated from one centrosome, supporting one "putative cytoplasmic compartment" (PCC). Platelet demarcation membrane (DM) is constructed on the boundary surface between neighbouring PCCs. Matured PCC, composing of a tandem array of platelet territories covered by a sheet of DM is designated as protoplatelet. Eventually, the rupture of MK results in release of platelets from protoplatelets. (Communicated by Tadamitsu Kishimoto, M.J.A.).  相似文献   

13.
We prove convergence to a motion by mean curvature by scaling diffusively a nonlinear, nonlocal evolution equation. This equation was introduced earlier to describe the macroscopic behavior of a ferromagnetic spin system with Kac interaction which evolves with Glauber dynamics. The convergence is proven in any time interval in which the limiting motion is regular.  相似文献   

14.
We propose a new mechanism for refrigeration powered by photons. We identify the strong coupling regime for which maximum efficiency is achieved. In this case, the cooling flux is proportional to T in the low temperature limit T→0.  相似文献   

15.
In this paper, the deflection angle of light by traversable wormholes, which are supported by the three-form fields, are studied. The specific forms of the redshift and shape functions that produce results compatible with the energy conditions at throat of the wormholes are used. Having used the well-defined parameter sets of the three-form wormholes, the photon geodesic motion is investigated under the effective potential of the wormhole background. As a result, it is discovered that the radius of the photon sphere can be used to analyze the geometrical structures of a physical wormhole. The analytical form of the effective potential is used to figure out a deflection angle of light caused by wormholes with the three-from fields. In this work, the relativistic images generated from the wormholes are also constructed.  相似文献   

16.
用二维PIC(Particle-in-Cell)程序模拟研究了强激光与稠密等离子体靶作用产生的无碰撞静电冲击波的结构和这种冲击波对离子的加速过程,研究发现由于冲击波前沿附近的双极电场的作用,具有一定初速度的离子能被该双极场俘获并获得加速,最终能够被加速到两倍冲击波速度.冲击波加速可以得到准单能的离子能谱,叠加在通过鞘层加速机理产生的宽度离子能谱上.还对不同激光强度和不同等离子体密度情况下形成的冲击波进行了比较.研究表明,强度相对较低的激光在高密度等离子体中可以产生以一定速度传播的静电孤波结构,后者只能加速 关键词: 强激光 稠密等离子体 无碰撞静电冲击波 离子加速  相似文献   

17.
强流脉冲电子束应力诱发的微观结构   总被引:1,自引:0,他引:1       下载免费PDF全文
利用强流脉冲电子束装置在各种工艺条件下对奥氏体不锈钢、单晶铝及多晶铝等面心立方金属进行辐照处理.利用扫描电子显微镜和透射电子显微镜等详细分析了辐照样品的变形组织与结构.通过分析,在一定程度上建立起强流脉冲电子束诱发的应力特征与变形结构之间的关系,并对目前现有的几种应力波数值模拟结果进行了分析.实验结果表明,强流脉冲电子束能够在材料内部诱发102—103MPa的应力,其传播方式与材料的 晶体结构关系密切.这一应力是导致材料深层性能与微观组织结构发生变化的根源所在. 关键词: 强流脉冲电子束 应力 微观结构 变形  相似文献   

18.
The resonance strength of the two-step process of nuclear excitation by electron capture followed by γ decay of the nucleus can be significantly increased in highly charged ions if the resonant capture proceeds via an excited electronic state with subsequent fast x-ray emission. For fully ionized 23892U and 23290Th, the x-ray decay stabilizes the system against internal conversion of the captured electron, with an increase of both nuclear lifetimes and resonance strengths of up to two orders of magnitude compared with the case when occupied atomic orbitals prevent the x-ray de-excitation. Applications of this effect to the measurement of the not yet experimentally observed nuclear excitation by electron capture and to dense astrophysical plasmas are discussed.  相似文献   

19.
Interference patterns generated by a regular lattice of SiO2 microspheres on a transparent support are used for the surface patterning of polyimide (PI) foils. Using 248 nm excimer-laser radiation, thousands to millions of holes with a full width at half maximum (FWHM) of 160±40 nm can be generated with a single laser pulse. Received: 1 March 2002 / Accepted: 4 March 2002 / Published online: 10 September 2002 RID="*" ID="*"Corresponding author. Fax: +43-732/2468-9242, E-mail: dieter.baeuerle@jku.at  相似文献   

20.
Growth by Ledges   总被引:4,自引:0,他引:4  
The prediction and observation of growth ledges at various moving interphase boundaries in solid-solid phase transformations has become increasingly widespread since first proposed in the early 1960's by Aaronson. The role of steps at the growth interfaces in several phase transformations is reviewed. For precipitate plates emphasis is placed on rationalizing experimental growth kinetics with mathematical models developed for the migration rate of a ledge. More complex transformations are employed to examine the possible role of growth ledges to account for microstructure development. In all cases, the growth ledge is shown to be necessary to fully understand solid-solid phase transformations.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号