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 62 毫秒
1.
HG-ICP-AES法测定山豆根中的微量元素   总被引:2,自引:0,他引:2  
建立微波消解-氢化物发生-电感耦合等离子体发射光谱联用技术测定中药山豆根中砷、锑、铋和锡的方法,对微波消解、氢化物发生、电感耦合等离子体原子发射光谱等工作条件进行优化,对还原剂L-半胱胺酸浓度进行了选择.在最佳工作条件下,砷、锑、铋和锡的检出限分别为0.006、0.009、0.003和0.005μg·g-1,相对标准偏差分别为6%、2%、3%和3%(n=10);加标回收率分别为102%、95%、98%和110%.  相似文献   

2.
微波消解-HG-ICP-AES法测定郁金中砷硒   总被引:5,自引:0,他引:5  
建立了微波消解-氢化物发生-电感耦合等离子体原子发射光谱联用技术测定郁金中微量元素砷、硒的方法,对微波消解、氢化物发生、电感耦合等离子体原子发射光谱工作条件进行了优化选择,并对增敏剂进行了选择.在最佳实验条件下,A s和Se的检出限分别为0.13μg.L-1和0.34μg.L-1,相对标准偏差分别为0.83%和1.8%,回收率分别为98%和95%.实验操作简便,结果满意.  相似文献   

3.
氢化物发生--电感耦合等离子体原子发射光谱法是现代分析技术的一种重要手段,本文中就该方法测定砷分族元素的氢化物发生原理,影响因素以及氢化物装置进行了阐述。  相似文献   

4.
黄胜  蒋小平 《广东科技》2010,19(14):56-57
用电感耦合等离子体发射光谱测试胶料类样品中的铅,通过干法灰化和微波消解法对胶料类样品进行消解分析对比;试验采用电感耦合等离子体发射光谱对上述两种方法处理的样品进行分析,试验结果表明:微波消解法比干灰化法具有较高的结果准确率,而且具有操作简便,消解速度快的特点。  相似文献   

5.
《贵州科学》2021,39(4)
新建一种电感耦合等离子体原子发射光谱(ICP-AES),同时测定氧化锌压敏陶瓷中铋、锑、钴、镍、锰、铬6种元素的方法。通过实验选择浓硫酸直接消解,酒石酸络合铋、锑元素。新方法前处理加标回收率在99.11%~102.23%,铋、锑、钴、镍、铬检出限均小于0.009μg/mL,锰检出限小于0.0005μg/mL,铋、锑、钴、镍、锰、铬6种元素相对偏差(RSD,n=7)均小于2%,为氧化锌压敏陶瓷产品的均匀性判定提供了一个简便快速的方法。  相似文献   

6.
建立微波消解-电感耦合等离子体发射光谱(ICP-AES)法同时测定煤飞灰中8种微量元素Al、Ca、Fe、Mg、K、Na、Mn和P。研究了微波消解体系和消解条件,煤飞灰样品用硝酸和氢氟酸微波消解分解,加入饱和硼酸溶液分解氟化物沉淀上机测定。用本法测定煤飞灰标准参考物质的结果与标准值相符。方法快速,准确,回收率为86%~105%;RSD均小于5%。  相似文献   

7.
建立了氢化物发生原子荧光法连续测定食品中砷、硒和锑的方法.采用微波消解的方法处理样品,研究了在酸性介质下,砷、硒、锑与硼氢化钾生成氢化物的反应行为,并对影响荧光强度的诸因素进行了试验和探讨.该法砷、硒、锑的线性范围分别为0~250,0~200,0~200μg/L,检出限分别为0.36,0.42,0.31μg/L,相对标准偏差为1.23%~4.85%.该法灵敏度高,检出限低,应用于实际样品的测定,结果满意.  相似文献   

8.
采用浓盐酸和氢氟酸作消解剂,以微波消解的方法处理原煤样品,氢化物发生-原子荧光光谱法测定煤中砷、硒,设定了最佳的样品处理条件和仪器测定条件.利用加标回收试验,对分析方法进行了验证.砷、硒的检出限分别为0.05 μg/L和0.06 μg/L,测定煤中砷、硒的回收率分别为97.9%~104.8%、96.6%~106.3%,RSD分别为1.26%~1.59%、1.68%~2.33%.  相似文献   

9.
将微波消解法与电感耦合等离子体质谱(ICP-MS)相结合,通过对微波消解条件及ICP-MS测定条件进行优化,建立了微波消解-电感耦合等离子体质谱法测定有机硅树脂中痕量铂的方法,并对方法的检出限、加标回收率和精密度进行了分析.实验表明:该方法线性范围宽,线性相关系数大于0.9999,方法检出限为0.024μg/L,加标回收率在86.40%~111.74%之间,相对标准偏差小于2.0%.该方法简便、快速、准确,完全能够满足有机硅树脂中铂含量的检测要求.  相似文献   

10.
建立了微波预还原-氢化物发生-电感耦合等离子体原子发射光谱联用技术测定中药三七提取液中无机硒的方法,对测定条件进行了优化选择,通过直接测定Se(IV)和微波辅助定量还原后测总硒,用差减法测得Se(VI)的量.Se(IV)的检出限为0.23 μg·L-1,相对标准偏差为2.0%,回收率为82%~104%,结果较为满意.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

13.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

14.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

18.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

19.
20.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  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