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 61 毫秒
1.
在PH=9.26的NH_3—NH_4Cl缓冲液中,Pd有一络合吸附波,其峰电位为—0.75V(vs.SCE),加入DEHSO后,出现Pd—DEHSO络合吸附波,峰形较前者好,峰电位为—1.05V(vs.SCE)。在1.88×10~(-6)mol/L—1.13×10 ~3tool/L之间有良好的线性关系,可准确用于Pd的测定。  相似文献   

2.
本文提出在锑(Ⅱ)—钼Ⅵ—HCI和乙醇体系中用极谱测定锗的新方法,其峰电位为-0.35V(V_5,SCE),测定下限为9×10~(-8)mol/L,机理研究表明此波属于杂多酸吸附波.  相似文献   

3.
建立了保健食品中叶酸的单扫描二阶导数示波极谱测定方法,并用正交条件试验确定了测定叶酸的最佳底液条件.在B R(Britton Robinson)缓冲体系(pH=7.22)中,叶酸产生一灵敏的极谱还原波,峰电位Ep=-0.89V(vs.SCE),其二阶导数波峰电流与叶酸浓度在3×10-7~5×10-6mol L范围内呈线性关系,线性方程i″p=59.441c+9.627,相关系数r=0.9991,检出极限为3×10-7mol L.  相似文献   

4.
在0.02mol/dm~3NH_4Cl-0.02mol/dm~3TEA-1.5×10~(-4)mol/dm~3BTZ底液中,悬汞电极上,Cu(Ⅱ)与苯并三氮唑配合物有一灵敏的极谱吸附不可逆还原波。本文用半微分极谱法进行了研究。峰电位随扫描速率增加而负移。当扫速为100mV/s时,Ep为-0.65V(vs.SCE)。t_(ads).60s时,峰高与铜浓度0.0005~0.065μg/ml之间存在正比关系。测得吸附配合物组成Cu:BTZ为1:1,条件形成常数β=3.5×10~4。在电极表面上,配合物的吸附近似服从Langmuir吸附等温式,其吸附系数α=7.9×10~4。方法应用于人体血清、头发、胃液和胃癌组织中微量铜的分析,与阳极溶出伏安法相对照,结果满意。  相似文献   

5.
单扫描示波极谱法测定酒石酸中的马来酸   总被引:2,自引:0,他引:2  
建立了极谱测定酒石酸中马来酸含量的方法。在4.8×10-2mol/LH3PO4-KH2PO4(pH1.12)缓冲溶液中,马来酸极谱还原波的峰电位Ep为-0.77V(vs.SCE),其二阶导数峰峰电流i″p与马来酸浓度在3.0×10-7~4.0×10-4mol/L范围内呈线性关系(r=0.9974,n=8)。10次测量1.6×10-5mol/L马来酸还原波二阶导数峰峰电流,相对标准偏差RSD为2.1%。1000(w/w)倍酒石酸不干扰测定。通过对四种合成样品中马来酸的测定和回收率试验考察该方法,结果令人满意。  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.
在0.56mol/L NaAc—0.04%Tiron 溶液中,铅(Ⅱ)与 Tiron 产生的络合物,在单扫描示波仪上可观察到一灵敏的极谱导数波,其峰电位为-0.49V(vs.SCE),峰电流与铅浓度在7.7×10~(-6)—6.8×10~(-6)mol/L 范围内成线性关系,检测限为3.8×10~(-(?))mol/L.应用该波测定了铜合金中的微量铅,结果良好,精密度和准确度均较满意,本文研究了形成铅-Tiron 络合物吸附波的条件,探讨了波的性质,用极谱法测定出其络合比为1:1.  相似文献   

8.
谷胱甘肽-铜极谱络合吸附波的研究   总被引:1,自引:0,他引:1  
在铜离子存在下,谷胱甘肽(GSH)在0.2mol/LNaAc-HAc(pH4.7)缓冲溶液中,与铜离子反应得到谷胱甘肽(GSH)与一价铜离子络合物,在单扫示波极谱上产生一灵敏的络合吸附波,峰电位在-0.59V处(vs.SCE),导数波高与谷胱甘肽浓度在4.0×10-8mol/L~1.0×10-5mol/L范围内分段成线性关系,检测限为1.0×10-8mol/L,相对标准偏差3.3%。研究了极谱波的性质,测得络合物组成为GSH:Cu(Ⅰ)=1:1,表观稳定常数为5.1×1019。  相似文献   

9.
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   

10.
采用交流阻抗和白光电流测量法,研究了锑在恒电位1.2V(VS.SCE)于0.025mol.dm-3Na2CO3+0.025mo1.dm-3Na2HCO3+0.500mol.dm-3Na2SO4(PH=9.98,30℃)缓冲溶液中阳极形成膜半导体性质.实验证明,该阳极氧化膜是一种n-型半导体,其平带电位Efb和施主密度ND分别为-0.53V(VS.SCE)和2.86×1018cm-3.  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.
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   

13.
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   

14.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

15.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  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.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

18.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

19.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

20.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  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