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1.
碱性条件下,双嘧达莫对luminol-K3Fe(CN)6-K4Fe(CN)6发光体系的有显著的增强作用.基于此建立了一种流动注射化学发光法测定片剂和人血清中双嘧达莫含量的方法.方法的线性范围是(9.0×10^-9~1.8×10^-8 mol/L),1.8×10^-8~1.8×10^-6 mol/L,检出限为1.0×10^-9 mol/L (S/N=3).相对标准偏差为0.8%(双嘧达莫1.0×10^-7 mol/L,n=10).  相似文献   

2.
采用胶柬电动毛细管电泳(MEKC)法测定维生素B的含量,电泳缓冲液为2.0×10^-2mol/L硼砂-硼酸缓冲液(pH=8.4),含2.5%(V/V)甲醇及10mmol/L十二烷基硫酸钠(SDS),在电泳电压20kV和检测波长254nm的条件下,维生素B4具有最佳的迁移时间和峰形;考察了缓冲溶液的pH、浓度、有机改性剂及胶束对维生素B4迁移行为的影响.结果表明:维生素B4在8.0×10^-7~5.0×10^-5mol/L内成良好的线性关系(r=0.9999),方法的检出限为1.2×10^-7mol/L,RSD为2.24%,该法已成功用于药剂、血清和尿液中维生素Ba的测定.  相似文献   

3.
ABA浸种对水稻生长发育及产量的效应研究   总被引:3,自引:0,他引:3  
以三系稻“汕优63”和两系稻“二优培九”为试材,用不同浓度植物激素脱落酸(0mol/L,5×10^-7mol/L,2.5×10^-6 mol/L,1.25×10^-5 mol/L,6.25×10^-5mol/L,3.125×10^-4mol/L)浸种,研究了ABA对水稻生长发育及产量的影响.结果表明:ABA浸种后,水稻秧苗素质和产量均优于对照,其中以6.25×10^-5mol/L浸种效果好,α-淀粉酶活性、发芽率、游离氨基酸含量、可溶性糖含量、叶绿素含量以及有效分蘖数均与其它处理差异显著.ABA溶液浸种处理后,“汕优63”、“二优培九”的平均产量分别比CK增产7.6%、12.5%,处理浓度为6.25×10^-5mol/L的产量最高,分别比对照提高了12.4%和20.8%.  相似文献   

4.
多环芳烃(PAHs)具有较高的荧光量子产率,非离子表面活性剂对其有增溶增敏作用。建立了吐温-80(TW-80)胶束增敏水中溶解态蒽(ANT)的直接荧光分析方法。所建立方法测定蒽的线性范围为1.6833×10^-8~1.29×10^-6mol/L,检出限为1.07×10^-8moil/L。该方法灵敏,应用于自来水样、江水样、湖水样的分析,取得了良好的效果,江水中回收率为94.6%-109.5%,湖水中回收率为90.5%~106.9%,自来水中回收率为86.9%~111.7%。为预测和治理水污染提供了一种灵敏、快速且简便的测试手段。  相似文献   

5.
基于铬(VI)对荧光试剂头孢拉定(CEFC)的荧光熄灭,建立了测定铬(VI)的荧光分析方法.在pH=3.0的盐酸介质中,最大激发与发射波长分别350nm和431nm及CEPC加入量为0.400g/L等条件下,相对荧光强度F护与铬(VI)的浓度lgc呈良好的线性关系,测定铬(VI)浓度的线性范围为1.0×10^-6-4.0×10^-4mol/L,检出限为8.3×10^-7-mol/L,常见的共存离子不干扰测定,此分析方法可用于环境水样中铬(VI)含量的测定.  相似文献   

6.
以聚碳酸酯超滤膜为基膜,采用化学镀的方法在聚碳酸酯膜纳米通道阵列内镀金.对金纳米通道表面进行氯离子修饰,在电场作用下电解质离子通过纳米通道时产生稳定的电流,当牛血清白蛋白(BSA)加入含BSA抗体的进样池后,与溶液中的牛血清白蛋白抗体分子形成BSA/抗体复合体,该大体积的复合体对电流产生一定的阻碍作用,引起相应的电流降,基于此发展了纳米通道检测BSA的传感技术.电流降低值与BSA浓度在3.64×10^-8~5.46×10^-7mol/L范围内具有线性关系,检测限(3S/N)为1.93×10^-8mol/L.  相似文献   

7.
研究了多巴胺(Dopamine,DA)在二茂铁乙酸(Ferrocenyl Acetic Acid,FcA)和Nation聚合物薄膜修饰玻碳电极(FcA/Nation/GCE)上的电化学行为,测定了DA在该修饰电极上的动力学参数,并用方波伏安法(SWV)对DA在FcA/Nation/GCE上的测定应用进行了研究.结果表明,与GCE相比,DA在FcA/Nation/GCE上的峰电流增大约10倍,氧化峰电位负移60mV,表明FcA/Nation/GCE对DA有良好的电化学催化作用;同时测得DA在FcA/Nation/GCE上的电子转移系数口为0.44,反应速率常数k。为0.106cm/s,表观扩散系数D0为5.4×10^-6cm^2/s.用SwV方法测得DA浓度在1.0×10^-5~2.0×10^-3mol/L范围内氧化峰电流(Jpa)与其呈良好的线性关系,线性拟舍方程为Jpa(μA)=47.524+16.508c(10mol/L),相关系数R=0.9989,检出限为1.0×10^-6mol/L,相对标准偏差为0.9%~1.1%,回收率为97.5%~100.1%.该测定方法简单快捷,测定结果令人满意.  相似文献   

8.
将氧化锌(ZnO)-壳聚糖(CHIT)-纳米金(nano—Au)形成复合杂化膜包埋血红蛋白(Hb),制备了无电子媒介体的第三代电流型生物传感器.该传感器对过氧化氢(H2O2)的还原显示出较好的电催化活性,固定在电极上的Hb在0.1mo//L磷酸盐缓冲溶液(PBS)中对过氧化氢响应灵敏度高,检测范围宽(3.9×10^-6~1.907×10^-72mol/L),检测下限低(1.53×10^-6mol/L(信噪比S/N=3)),并且表现出良好的稳定性和高选择性.  相似文献   

9.
L-半胱氨酸修饰金电极的制备及应用研究   总被引:1,自引:1,他引:0  
通过电化学方法制得L-半胱氨酸修饰金电极,以该修饰电极为工作电极,建立了一种灵敏的、选择性的测定痕量铜离子的新方法.用该电极在含铜离子的NaH2PO4-Na2HPO4缓冲液中搅拌富集,对不同浓度的铜离子进行电化学测定时仅仅是峰电流发生改变,且峰电流随铜离子浓度的增大而增大,在1×10^-9~1×10^-5mol/L之间出现良好的线性关系.其最低检测限可达10^-10mol//L.  相似文献   

10.
采用电化学方法制备聚对苯二酚薄膜修饰玻碳电极(PHQ/GCE),并用该电极对抗坏血酸(AA)进行测定.研究发现:在0.2 mol/L Na2HPO4-NaH2PO4(PBS,pH 7.0)缓冲溶液中,以0.1 mol/L KCl作支持电解质,PHQ/GCE对AA有明显的催化氧化作用.同时,应用线性扫描循环伏安法对AA进行定量分析,其氧化峰电流与AA浓度在5.0×10-6~1.0×10-1 mol/L范围内呈现良好的线性关系,检出限为1.0×10-7 mol/L.对此机理进行详细研究,结果表明聚对苯二酚修饰玻碳电极上带有的酚羟基与脱氢抗坏血酸自由基之间形成的氢键是电催化氧化的主要原因.  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.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

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