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1.
采用共价键合法将壳聚糖修饰的掺硼金刚石薄膜电极作为工作电极,对底液pH为4.0的0.1mol/LKH2PO4溶液中的I^-进行了循环伏安以及阳极溶出法进行了检测.得到检测限为1.2×10^-7mol/L,线性范围为1.4×10^-6mol/L至3.1×10^-3mol/L,相关系数为0.988.实验结果表明:掺硼金刚石薄膜修饰电极检测灵敏,且电极再生性很好,使电极寿命更长,具有极好的应用前景.  相似文献   

2.
掺硼金刚石薄膜涂层刀具的制备及试验研究   总被引:1,自引:0,他引:1  
采用偏压增强热丝化学气相沉积法,以硼酸三甲酯为掺杂源,以WC-Co硬质合金刀具为衬底,制备了不同掺硼浓度的金刚石薄膜涂层刀具.通过采用扫描电子显微镜(SEM)、拉曼光谱及压痕测试对涂层刀具的表面形貌、薄膜质量和膜-基附着力进行了研究,分析了硼元素对薄膜质量和刀具性能的影响.研究结果表明:硼掺杂可以有效抑制刀具表层钴的扩散,改变金刚石薄膜的成分;掺硼金刚石薄膜的晶粒取向主要是{111},随着掺硼浓度的增加,金刚石薄膜的晶粒变小,平均晶粒尺寸从10 μm下降到2 μm;金刚石薄膜的拉曼光谱中心声子线随着掺硼浓度的增加向低频方向漂移,强度降低,且出现多晶石墨峰;涂层的膜-基附着力在硼碳摩尔比B/C=3×10-3时最佳.通过对碳化硅颗粒增强铝基复合材料的切削加工试验表明,在适当的掺硼浓度下金刚石薄膜涂层刀具的切削性能得到了显著改善.  相似文献   

3.
本文利用循环伏安法,在裸玻碳电极上成功地制备了聚茜素红薄膜修饰电极(PARSE),详细研究了该修饰电极对NO-2的电催化作用.实验结果表明,PARSE对NO-2具有良好的电催化作用.催化峰电流与NO-2浓度在2.5×10-3~2.5×10-5mol/L之间呈良好的线形关系,线性相关系数为0.999 6,检测限可达5×10-6mol/L,用于腌菜样品中NO-2含量的测定,取得满意结果.  相似文献   

4.
以多壁纳米碳管(MWCNTs)为电子媒介体和酶的吸附载体,利用层层累积的自组装技术固定葡萄糖氧化酶(GOx)的多层(MWCNTs/GOx)n复合薄膜修饰电极,制备了一种新型葡萄糖生物传感器。结果表明:传感器对葡萄糖的响应电流值随着MWCNTs/GOx复合薄膜层数的不同而变化,当MWCNTs/GOx复合薄膜的层数为6时,响应电流值达到最大。(MWCNTs/GOx)6复合薄膜修饰的葡萄糖生物传感器对3×10-2mol/L葡萄糖的响应电流为1.63μA,响应时间仅为6.7 s。该生物传感器检测的线性范围为5×10-4~1.5×10-2mol/L,最低检测浓度可达0.9×10-4mol/L。  相似文献   

5.
利用循环伏安法制备了聚结晶紫薄膜修饰电极(PCVE),详细研究了该修饰电极对生物分子多巴胺(DA)和尿酸(UA)的电催化作用.结果表明,PCVE对DA和UA具有较强的电催化作用,并且对抗坏血酸(AA)具有较强的抗干扰作用,允许高达1 000倍以上AA存在而不干扰痕量DA的测定.将PCVE结合差分脉冲伏安(DPV)技术,对DA的检测线性范围为4.0×10-7 mol/L~2.5×10-5 mol/L,检测限可达3.5×10-8 mol/L;对UA的检测线性范围为5.0×10-7 mol/L~5.0×10-5 mol/L,检测限达5.0×10-8 mol/L.利用该法可以对DA和UA进行同时测定,将该法用于尿液中尿酸的测定,取得满意结果.  相似文献   

6.
利用循环伏安法(Cv)研究了壳聚糖薄膜修饰电极(CTS/GCE)测定SO32-的最佳条件.结果表明,在0.2mol/L HCl-KCI(pH=1.7)底液中,还原峰电流与SO32-的浓度在2.0× 10-4~2.0× 10-2mol/L范围内呈良好的线性关系,检测限达4.5×10-5mol/L.线性方程为ipc(μtA...  相似文献   

7.
利用聚茜素红薄膜修饰电极对氯霉素的电催化作用,建立了对氯霉素含量进行定量分析的一种电分析方法.在0.1 mol/L KH2PO4-Na2B4O7(pH=6.0) 0.2 mol/L KCI溶液中,氯霉素的浓度在3.8×10-4~4.6×10-3mol/L范围内与峰电流呈良好的线性关系,线性回归方程和线性相关系数分别为:ip(μA)=0.190 1.109×10-4(mol/L),r=0.999 8,检测限可达5×10-6 mol/L.利用该法对氯霉素滴眼液进行定量分析,8次平行样品分析结果的相对标准偏差小于3%!,完全满足定量分析的要求.  相似文献   

8.
利用循环伏安法,将灿烂绿(BG)电聚合于玻碳基体电极表面,成功地制备出对盐酸利多卡因(LH)具有良好电催化作用的聚灿烂绿薄膜修饰电极(PBGE).结果表明,在0.1 mol/L KNO3+0.05 mol/L PBS(p H=6.8)体系中,LH的浓度在6.9×10-6~1.4×10-4mol/L范围内时,氧化峰电流与浓度呈现良好的线性关系,线性方程和线性相关系数分别为:ipa(μA)=-11.71-2.85×10-5 CLH(mol/L),R=0.998 8,检测限可达3.5×10-6mol/L.将该法用于盐酸利多卡因样品的测定,8次平行测定结果的相对标准偏差不大于4.9%,样品回收率范围为95.6%~102.9%,符合微量分析的要求.  相似文献   

9.
以离子液体1-丁基-3-甲基咪唑六氟磷酸盐(BmimPF6)为活性物质制得离子选择性电极,该电极对离子液体BmimCl有较好的电位响应,线性响应浓度范围为1×10^-5mol/L~1×10^-2mol/L.用十二烷基硫酸钠(SDS)与BmimPF6进行阴离子交换制得的1-丁基-3-甲基咪唑十二烷基硫酸盐(BmimDS)作为活性物质,能降低电极的检测下限,线性响应浓度范围拓展为1×10^-6~1×10^-2mol/L.该电极显示出良好的稳定性和重现性.此外,该电极可作为电位滴定法的指示电极用于对四丁基氯化铵(TBACl)、十二烷基硫酸钠(SDS)的滴定分析.  相似文献   

10.
制备了MWNT-石墨糊修饰电极,研究了以该电极为工作电极,用阳极溶出伏安法测定Cu2 的最佳实验条件.在0.6mol/L硫酸溶液中,于-0.6V(vs.SCE)处富集420s后进行阳极溶出伏安扫描.Cu2 浓度在1×10-6-2×10-5mo/L范围内与峰电流成线性关系;在5×10-7-4×10-6mo/L范围内与峰电流二次导数呈线性关系.检出限为1.25×10-7mol/L.  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.
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   

14.
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   

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.
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   

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