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1.
吸附伏安法同时测定中草药中痕量的镍和钴   总被引:2,自引:0,他引:2  
提出一种有效的测定痕量镍和钻的吸附伏安法。利用悬汞电极作为工作电极,在0.005mol/L NH_3~0.06 mol/L NH_4Cl—3.0×10~(-6)mol/L锌试剂的最佳底液中,测定镍和钴的线性范围分别为1×10~(-10)~8×10~(-8)mol/L和1×10~(-10)~1×10~(-7)mol/L,检测下限均为5×10~(-11)mol/L。在工作中探讨了镍、钻和锌试剂配合物的吸附伏安行为及其在电极表面上的电化学反应机理。研究证明,该方法灵敏、可靠、省时,特别适用于中草药中痕量镍和钴的定量分析。  相似文献   

2.
以自制的铂电极为基础,制备了葡萄糖酶电极,并测试了淀粉-糖化酶水解液中的葡萄糖,测定的范围为2×10~(-6)~5×10~(-3)mol/L。  相似文献   

3.
本文报道了用碳纤维电极用运导数伏安法和循环伏安法测定V_E,在0.01mol/LHCIO_4——CH_3CH_2OH溶液中,得到了一对氧化——还原电对,线性范围是1.0×10~(-6)~5.0×10(-8)mol/L。检出限为5.O×10(-10)mol/L,并研究了反应机理。  相似文献   

4.
提出了吸附溶出催化伏安法测定痕量锗的方法。该方法最佳体系为0.15 mol/L KCl+1.0×10~(-3) mol/L 3,4-二羟基苯甲醛(DHB)+2.0×10~(-3)mol/L EDTA+3.0×10~(-3)mol/L V(Ⅳ),pH2.15。其线性范围为1.2×10~(-10)~6.O×10~(-8)mol/L,最低检出浓度为3.6×10~(-11)mol/L Ge(Ⅳ)。  相似文献   

5.
以聚茜素红薄膜修饰电极(PARE)为工作电极,0.05 mol/LHAc-NaAc(pH 5.0)为支持电解质,通过差分脉冲伏安法研究了丹宁酸在修饰电极上的伏安行为.结果表明,当丹宁酸浓度在5.0×10-6~5.0×10-3mol/L范围内,丹宁酸的浓度与氧化峰电流成线性关系,线性方程为i(μA)=0.2768c(10-6mol/L)+2.636,r=0.9966,检出限达1.0×10-7mol/L.方法简便,用于茶叶中丹宁酸的测定,7次测定的RSD%为2.1.  相似文献   

6.
在0.10mol/L LiCl-0.02mol/L HCl-8.0×10-3mol/L KBrO3支持电解质中,苯丙氨酸产生一个极谱催化波,峰电位为-1.65V(vs.SCE).该极谱催化波二阶导数峰电流与苯丙氨酸的浓度在2.0×10-5~2.5×10-3mol/L范围呈线性关系,其检测下限为6.5×10-6mol/L.本文建立了苯丙氨酸的分析测定方法,讨论了该极谱催化波的产生机理.  相似文献   

7.
本文探讨了蒿甲醚在0.25mol/L磷酸-50%甲醇体系中直流极谱的一些特性,确定了它在该体系中有一很好的受扩散控制为主的极谱波,其半波电位为-0.28V(对汞层阳极),温度系数为+1.9%/℃,电子得失数为2;在25.0℃时的扩散系数为:D=3.30×10~(-6)cm~2/s;在4.0×10~(-5)-8.0×10~(-4)mol/L浓度范围内有较好的线性关系.  相似文献   

8.
建立了多壁碳纳米管(MWCNT)修饰玻碳电极,差分脉冲伏安法测定氯霉素(CAP)的新方法,并应用于氯霉素眼药水的测定.实验结果表明,在0.1 mol/LNaOH体系中氯霉素在多壁碳纳米管修饰电极上的催化还原峰电流大于裸电极上的还原峰电流.CAP浓度在2.9×10-5~2.0×10-4mol/L范围内与峰电流成线性关系,检出限为5.0×10-6mol/L,线性相关系数(r)为0.9901,相对标准偏差(RSD%,n=7)为1.55%.  相似文献   

9.
聚组氨酸修饰电极测定多巴胺的研究   总被引:2,自引:0,他引:2  
本文研究了多巴胺在聚组氨酸修饰电极上的循环伏安行为.在pH7.0的磷酸盐缓冲溶液中,用线形扫描伏安法测定多巴胺的线性范围为:6.0×10-8~1.0×10-5mol/L,1.5×10-5~1.0×10-3mol/L,检出限为4×10-8mol/L.用于药剂中多巴胺的测定,结果满意.  相似文献   

10.
槐米中芦丁和槲皮素的毛细管电泳-电化学检测   总被引:12,自引:0,他引:12  
用毛细管区带电泳 -电化学检测法测定了中药槐米中芦丁和槲皮素的含量。研究了电极电位、电解液酸度和浓度、电泳电压及进样时间等对电泳的影响 ,得到了较为优化的测定条件。以直径为 30 0 μm的碳圆盘电极为检测电极 ,电极电位为 0 .90V (vs .SCE) ,在 10 0mmol/L硼酸盐缓冲液 (pH 9.0 )中 ,上述两组分在 10min内完全分离。芦丁和槲皮素浓度与电泳峰电流分别在 7.5× 10 - 7~ 1.0× 10 - 3和 5 .0× 10 - 7~ 1.0× 10 - 3mol/L范围内呈良好线性 ,检测下限分别为 4 .34× 10 - 7和 2 .2 5× 10 - 6 mol/L。 7次测定含 5 .0× 10 - 4 mol/L芦丁和槲皮素的试样溶液 ,峰高的相对标准偏差分别为 2 .5 6 %和 4 .11% ,五次测得的平均回收率分别为 97.80 %和 96 .84 %  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   

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