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1.
方波溶出伏安法同时测定废水中微量的锌、镉、铅和铜   总被引:4,自引:1,他引:4  
报道了用方波溶出伏安法同时测定废水中微量锌、镉、铅和铜的一种方法.在浓度为0.15mol/L,pH=5.0的氯化铵分散体系中,温度18℃的条件下,Zn2 、Cd2 、Pb2 和Cu2 均灵敏地产生溶出峰,峰位分别为:-1.13V、-0.72V、-0.50V、-0.22V(vs,S.C.E).线性范围分别为2×10-7~2×10-5、2×10-7~2×10-5、1×10-7~2×10-5和5×10-7~5×10-5mol/L,检测限为2×10-8~2×10-7mol/L,回收率为87.7~102.4%.  相似文献   

2.
用线性扫描极谱法研究瑞格列奈的电化学行为.在0.1 mol·L-1 Na2HPO4-KH2PO4缓冲溶液(pH6.86)中,瑞格列奈于-1.180 V(vs.SCE)处产生一灵敏的吸附波.在5.0~500.0μg·L-1范围内,其一次微分线性扫描峰电流与浓度呈良好的线性关系,相关系数r=0.9984(n=10),检出限为3.5μg·L-1.以50.0μg·L-1瑞格列奈溶液作6次平行试验,RSD为0.83%,回收率在97.4%~107.6%之间.该法可用于片剂中瑞格列奈含量的测定.  相似文献   

3.
邻菲啰啉的电化学性质研究   总被引:2,自引:0,他引:2  
0 .5mol·L- 1 的一氯乙酸和 0 .1g·L- 1 的十二烷基磺酸钠溶液中 ,邻菲啉有一灵敏极谱峰 ,其峰电位是 -0 .75V(vs.SCE) .峰电流与邻菲啉的浓度在 4.0× 10 - 7~ 3.8× 10 - 5mol·L- 1 范围内呈线性关系 (r =0 .9985 ) ,检测下限为 2 .0×10 - 7mol·L- 1 .利用线性扫描极谱法和循环伏安法研究了邻菲啉的电化学性质  相似文献   

4.
利用微分电位溶出分析法,以0.09 mol/L草酸、7.5×10-5mol/L中性红为底液,同时测定了4种样品中的铅、锡含量,二元素峰电位分别为-0.52 V和-0.62 V(vs SCE),铅、锡的线性范围分别为2.0~100.0 ng/mL、5.0~250.0 ng/mL.当富集时间为60 s时,铅、锡的检出限分别为2 ng/mL和5 ng/mL.将此法应用于测定食品中痕量铅和锡,结果满意.  相似文献   

5.
报道了同时测定痕量锌和镉的新方法 .在 0 .0 1mol/LHAc - 0 .0 1mol/LNaAc- 1.2× 10 - 5mol/L乙醛酸缩氨基硫脲 (GATSC)中 ,Zn -GATSC和Cd -GATSC均产生非常灵敏的吸附波 ,峰电位分别是 - 0 .82V和 - 0 .4 3V(vs·SCE) ,峰电流和锌、镉的浓度分别在 3.0× 10 - 8~ 8.0× 10 - 7mol/L和 1.0× 10 - 8~ 6 .0× 10 - 7mol/L范围内成直线关系 ,检测限分别是 8.0× 10 - 9和 3.0× 10 - 9mol/L .该方法用于测定水中痕量锌和镉 ,结果令人满意  相似文献   

6.
本文研究了N-(8-喹啉基)-N’-苯甲酰基硫脲的极谱性质。发现在0.1mol·L~(-1)KBr-0.05mol·L~(-1)NaOH/K_2HPO_4溶液中,其产生三个清晰的阴极化示波极谱波,二次导数峰电位分别为-0.40V,-0.77V及-1.20V(VS.SCE),相应的线性范围依次是1.0×10~(-6)~4.0×10~(-5)mol·L~(-1),1.0×10~(-6)~5.0×10~(-5)mol·L~(-1),1.0×10~(-8)~2.0×10~(-6)mol·L~(-1)。文中对极谱波性质和电极反应机理进行了探讨。研究表明,前两峰分别为>C=S,>C=O的电还原,后者为氢催化波。  相似文献   

7.
灰黄霉素在0.1 mol*L-1 HAc-NaAc缓冲溶液(pH=5.86)中,于Co-GC离子注入修饰电极上,形成一良好的线性扫描伏安还原峰,峰电位Ep=-0.63 V(vs.SCE).峰电流ip与灰黄霉素浓度在5.0×10-9~1.1×10-6 mol*L-1范围内成线性关系,相关系数为0.999 8,检测限可达2.0×10-9 mol*L-1,可用于痕量物质的测定.用线性扫描与循环伏安法等手段研究了体系的性质,实验表明电极反应为不可逆吸附过程.用AES和XPS对电极表面进行了表征.  相似文献   

8.
采用电化学方法制备了纳米氢氧化镍/过氧化聚吡咯复合膜修饰电极(Nano-Ni(OH)2/PPyox),研究了该修饰电极的电化学性质及其电催化活性.结果表明:在0.10 mol·L-1 NaOH溶液中,该修饰电极对葡萄糖具有较强的电催化活性,且具有良好的抗干扰性.在优化实验条件下,安培法检测葡萄糖的线性范围为2.0×10-7 ~5.0×10-5 mol·L-1(r =0.999 7)和5.0×10-5~1.0×10-3 mol·L-1(r=0.999 4),灵敏度分别为1017 μA·mM-1 ·cm-2和733 μA·mM-1·cm-2.  相似文献   

9.
本文提出微波高压消解-火焰原子吸收光谱法(AG-FAAS)测定食用菌中痕量铜、锌、铁和锰的方法.该方法检出限Cu2 、Zn2 、Mn2 为:1.0×10-9g/mL和Fe3 为:5.0×10-9g/mL.Mn2 、Fe3 Cu2 和Zn2 的含量分别在0.250~4.000、0.500~2.500、0.100~0.500和0.300~1.500μg/mL范围内符合比尔定律,相关系数为0.9997~0.9999.此法用于茶树菇、香菇中铜、锌、铁和锰含量的测定,结果令人满意.  相似文献   

10.
以L-半胱氨酸作为电极修饰剂,采用循环伏安法研究L-Cys/GC电极的制备和DA在该修饰电极的电化学行为及其测定.DA在pH=6.684的磷酸盐缓冲溶液中,在L-Cys/GC电极上产生一对灵敏的氧化还原峰,峰电位分别为Epa=0.180 V和Epc=0.125 V(vs.SCE).同时用伏安法测定DA的线性范围为1×10-3~1.0×10-6 mol/L,检出限可低达1.0×10-7mol/L(S/N=3).对1×10-4 mol/L DA平行测定50次,其相对标准偏差约为2.5%.该电极可望进一步发展为微电极,用于生物活体内的神经递质DA的实际检测.  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.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

20.
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