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1.
采用涂覆法制备多壁碳纳米管(MWCNT)-离子液体([BMIM]PF6)修饰电极,研究Cu2+在该修饰电极上的阳极溶出伏安行为。考察了实验条件对Cu2+电化学行为的影响。研究表明,Cu2+在修饰电极上可得到灵敏的溶出峰。在优化的实验条件下,Cu2+在1.0×10-6~1.0×10-5mol/L浓度范围内与其氧化峰电流呈...  相似文献   

2.
采用循环伏安法和方波溶出伏安法研究了对乙酰氨基酚(ACOP)在玻碳电极上的电化学行为,结果发现,在pH=6.86的生理介质中,ACOP在玻碳电极上于0.53 V左右产生一对准可逆的氧化还原峰,在2.0×10-6~3.0×10-4mol/L浓度范围内与方波阳极溶出伏安峰电流有良好的线性关系,r=0.995 4,检出限为1.0×10-6mol/L.对5.0×10-5mol/L的ACOP重复测定8次,相对标准偏差为2.4%,可用于药剂中ACOP含量的测定.  相似文献   

3.
Hg2+在纳米二氧化钛膜电极上的电化学行为研究   总被引:3,自引:0,他引:3  
以nano-TiO2膜修饰玻碳电极作为工作电极,采用阳极溶出伏安法测定水相中的痕量Hg2 .详细研究了Hg2 在nano-TiO2膜修饰玻碳电极上的电化学响应行为,并对各种实验参数进行了优化.实验结果表明,在pH 4.5的磷酸盐缓冲溶液中,在-1.2 V电位下富集7 min,再静置60 s后阳极化扫描,Hg2 在nano-TiO2修饰的玻碳电极上于0.14 V出现一个灵敏尖锐的阳极溶出峰.相比于裸玻碳电极,该峰电流大大提高,且峰电位略微负移,表明nano-TiO2对Hg2 的溶出具有一定的增敏作用.在最优化实验条件下,Hg2 溶出峰电流与其浓度分别在2×10-8~1×10-6mol/L和2×10-6~8×10-6mol/L呈良好的线性关系,富集12 min,检出限可达5×10-6mol/L.该修饰电极还具有一定的抗干扰能力,将其应用于实际水样中Hg2 的检测,结果令人满意.  相似文献   

4.
应用组合法将壳聚糖、石墨粉以及石蜡油按一定比例调和制成壳聚糖碳糊修饰电极,该修饰电极对I-的电极反应具有良好的促进作用.详细研究了I-在该修饰电极上的阳极溶出伏安特性,并对相关机理进行了探讨.实验表明,修饰电极在pH为4.5的0.1 mol/LKCl溶液中对I-具有良好的吸附性和选择性,电极响应灵敏.其阳极溶出峰电流在5.0×10-6 mol/L~2.0×10-3 mol/L I-浓度范围内呈良好线性关系,检出下限达2.0×10-7 mol/L.将该法应用于碘酒中碘含量的测定,取得较好的结果,7次平行样品分析结果的相对标准偏差为4.3%,样品回收率范围为94.5%~100.2%.  相似文献   

5.
制备了多壁碳纳米管(MWCNT)-离子液体([BMIM]PF6)修饰电极并作为工作电极,采用阳极溶出伏安法检测Hg2+。研究表明,Hg2+在修饰电极上可得到灵敏的溶出峰。考察了实验条件对Hg2+在该修饰电极上溶出伏安行为的影响。在优化的实验条件下,Hg2+在1.0×10-6mol/L~1.0×10-4mol/L浓度范围内与其溶出峰电流呈良好的线性关系,相关系数为0.9992,检出限为1.0×10-7mol/L。该修饰电极制备简单,用于微量汞的检测,效果良好。  相似文献   

6.
应用循环伏安法、微分脉冲伏安法对呋喃妥因在玻碳电极上的伏安行为及其测定进行了研究 .实验发现 ,在 0 .10 mol/ L的 HCl底液中 ,对其进行微分脉冲阴极溶出伏安扫描 ,于 - 0 .0 7V(vs.SCE)产生一还原峰可用于呋喃妥因的定量测定 .该还原峰的微分脉冲伏安峰电流与呋喃妥因的浓度在 5.0 0× 10 -7~ 3.0 0× 10 -5mol/ L范围内呈良好的线性关系 .对 1.0 0× 10 -5mol/ L的呋喃妥因溶液中进行 10次实验 ,该峰的峰电流相对标准偏差为 2 .6 8% .本方法检测限为 2× 10 -8mol/ L.  相似文献   

7.
制备了羧基化碳纳米管修饰碳糊电极(MWCNT/CPE),并研究了Cu(Ⅱ)-SPAPT络合物在该电极上的吸附伏安行为,建立了一种测定痕量铜的新方法。采用二阶导数线性扫描溶出伏安法进行分析。结果表明:在0.1 mol/L的HAc-NaAc(pH=4.0)中,于-400 mV处搅拌富集一定时间,从-400~600 mV范围内以250 mV/s的扫描速度线性扫描,络合物吸附在MWCNT/CPE表面,于66 mV(vs.SCE)处产生一灵敏的阳极溶出峰,其峰电流与Cu(Ⅱ)浓度在4×10-11mol/L-8×10-9mol/L和8×10-9mol/L-1×10-7mol/L范围内分两段呈良好的线性关系,检出限(S/N=3)为2.2×10-11mol/L(富集时间240 s)。同时,探讨了电极反应机理。该方法操作简便、灵敏度高,应用于人发中铜含量的测定,结果满意。  相似文献   

8.
将疏水性离子液体N-己基吡啶六氟磷酸盐作为粘合剂和修饰剂,与碳粉混合,然后压制到电极管中制备出一种碳离子液体糊电极(CILE).用预镀铋膜法将铋离子沉积在CILE表面制备的铋膜修饰电极(Bi/CILE)作为工作电极,利用阳极溶出伏安法测定痕量铅离子.在p H 5.0的HAcNa Ac缓冲溶液中,当富集电位为-1.4 V,富集时间为300 s,铅离子有一个灵敏的阳极溶出伏安峰,峰电位为-0.457 V(vs.SCE),在8.0×10-8mol/L~4.0×10-5mol/L浓度范围内,氧化溶出峰电流与Pb(II)的浓度呈很好的线性关系,检出限为2.05×10-8mol/L,重现性良好,并将该方法成功用于生活自来水样中铅离子含量的测定.  相似文献   

9.
研究了玻碳汞膜电极上L-半胱氨酸(L-Cys)的直接和间接测定方法,并建立了间接和直接测定的最佳条件.在pH=4.56的缓冲溶液中L-Cys于-0.44 V处有一灵敏的不可逆的循环扫描还原峰,其峰电流与L-Cys的浓度在1×10-6~1×10-4 mol/L内呈良好线性关系(r=0.998 9).另外,根据L-Cys在适当的pH条件下与铜离子的络合作用,通过阳极溶出伏安法测定Cu2+来间接测定L-Cys的含量,本法L-Cys浓度在2×10-7~3×10-6 mol/L内呈良好线性关系(r=0.999 2).2种方法可成功地用于合成样品中L-Cys的测定.  相似文献   

10.
MWNT-石墨糊电极阳极溶出伏安法测定铅   总被引:3,自引:0,他引:3  
制备了多壁碳纳米管(MWNT)-石墨糊电极,实验发现可用该电极阳极溶出线性扫描法测定Pb2+.实验表明以MWNT、石墨粉和液体石蜡的质量比为4∶4∶5的MWNT-石墨糊电极为工作电极,在-0.46V处测定出Pb2+的阳极溶出峰,其峰电流的二阶导数值与Pb2+浓度在1.06×10-7-1.06×10-5mol/L范围内呈线性关系,检出限为3×10-8mol/L.试样测定的回收率为97.0%-104.7%.  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.
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   

18.
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   

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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