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1.
在pH=7.6的BR缓冲体系中,氨基黑与苦参碱发生反应,形成离子缔合物时,溶液颜色发生改变.其最大显色波长位于532 nm处,在最大显色波长处,苦参碱浓度与溶液的显色呈良好的线性关系,可用于苦参碱的测定.苦参碱的浓度为0.08×10-6~3.0×10-6g/mL范围内符合比尔定律,相关系数R=0.999 2,摩尔吸光系数为6.46×104L/(mol.cm),检出限为0.025μg/mL.方法快速、灵敏、操作简便,可用于片剂和尿液中苦参碱的测定,结果满意.  相似文献   

2.
在磷酸介质中,建立了以二溴邻硝基苯基荧光酮为显色荆、吐温-80为表面活性剂、在微波消解条件下用分光光度法测定痕量锗的新方法.探讨了测定痕量锗的最佳显色条件和测定条件.配合物最大吸收位于540 nm波长处,其摩尔吸光系数ε=0.886×105L/(mol·cm),线性回归方程A=2.30×10-3ρ-7.1×10-3(ρ的单位为μg/mL).相关系数r=0.999 9,检出极限为7.86×109g/mL,结果可以直接用于中草药中痕量锗的测定.  相似文献   

3.
建立RP-HPLC同时测定心肌安颗粒剂中含绿原酸、芍药苷两种有效成分的方法.采用Dia-monsil C18(4.6 mm×250 mm,5μm)色谱柱,以乙腈-0.2%磷酸水为流动相梯度洗脱,流速1.0mL/min,柱温35℃,检测波长230 nm.绿原酸和芍药苷质量浓度分别在20~120μg/mL(r=0.999 9)和30~180μg/mL(r=0.999 8)范围内与峰面积线性关系良好,绿原酸和芍药苷平均加样回收率(n=6)分别为99.38%(RSD=0.96%)和99.91%(RSD=0.82%).三批制剂测定结果显示,含绿原酸量为10.36 mg/g(RSD=0.73%),含芍药苷量为8.18 mg/g(RSD=0.58%).本方法快速、准确,重复性好,可用于同时测定心肌安颗粒剂中绿原酸和含芍药苷的量.  相似文献   

4.
双波长双指示剂催化动力学光度法测定痕量亚硝酸根   总被引:1,自引:0,他引:1  
在磷酸介质中,利用亚硝酸根催化溴酸钾氧化亮绿和甲基橙褪色的指示反应,建立催化光度法测定痕量亚硝酸根的新方法.该反应的最大吸收峰在500 nm和640 nm处,线性范围1-11μg/25 mL,其检出限为2.82 × 10-10g/L,相对标准偏差0.05%.本方法灵敏度高,体系稳定,具有较好的选择性,用于自来水中痕量亚硝酸根的测定,结果较为满意.  相似文献   

5.
在磷酸介质及加热条件下,钌(Ⅲ)对高碘酸钾氧化二安替出林对羟基本基甲烷(DApHM)显色反应有明显催化作用,由此建立测定痕量钉的催化分光光度分析法。λmax=440nm,其检出限为6.9g×10-10g/mL,钉的含量在0-6μg/L范围内将会比尔定律,并且测定了一些动力学参数。本法用于岩矿中痕量钌的测定,其结果满意。该法灵敏度较高,稳定性较好。  相似文献   

6.
研究了新显色剂对二甲氨基偶氮氯膦与稀土元素的显色反应.在05mol/L盐酸介质中,试剂与轻、重稀土元素均能发生显色反应,其络合物的表现摩尔吸光系数ε值分别在(40×50)×104和(05~15)×104L·mol-1·cm-1.当有一定量的CTMAB、乙醇和草酸存在时,试剂与轻稀土元素显色灵敏度提高,而重稀土几乎不显色.轻稀土元素含量有0~12g/25mL范围内与试剂所形成的络合物在662nm,604nm,531nm3个波长处吸光度绝对值之和与轻稀土的浓度具有良好的线性关系,可利用3波长处吸光度值叠加的方法测定其含量,ε值达14×105L·mol-1·cm-1.该方法可用于钢、铝合金、铸铁试样中轻稀土元素含量的测定.  相似文献   

7.
在pH7.8的BR缓冲体系中,番红花红T与十二烷基硫酸钠作用,形成离子缔合物,溶液颜色发生改变.其最大显色波长位于510nm处,在显色波长处,十二烷基硫酸钠的浓度与溶液的显色呈良好的线性关系,可用于十二烷基硫酸钠的测定.在波长为510nm处,十二烷基硫酸钠的浓度为0.5~5.0μg.mL-1范围内遵守比尔定律,相关系数分别为R=0.9992,摩尔吸光系数为7.4×104 L.mol-1.cm-1,检出限为:0.059μg.mL-1.该方法快速、灵敏、操作简便,用于环境水样中十二烷基硫酸钠的测定,结果满意.  相似文献   

8.
在盐酸介质中,痕量亚硝酸根与罗丹明6G发生亚硝化反应,使罗丹明6G溶液在527nm处的共振散射光强度明显下降,从而建立了共振光散射法测定痕量亚硝酸根的新方法.方法的线性范围为0.02×10-6~0.2×10-6g/mL,检出限为1.22×10-8gm/L.方法用于废水和蔬菜中痕量亚硝酸根的测定,回收率在95.5%~104.9%之间。  相似文献   

9.
报道了维生素B2在酸性溶液中的极谱氧化波及其应用.在0.12 mol/L的硫酸溶液中,维生素B:在-0.04V(vs.SCE)处产生一个灵敏的吸附性氧化峰,其二阶导数波峰尖锐、对称,波高与0.025×10-6~9.0×10-6g/mL范围内的维生素Bz呈线性关系,相关系数为0.997,检出限达0.020×10-6g/mL对于5.0×10-6g/mL的维生素B2平行进行11次测试,RSD为1.10%.极谱波的波高在室温下可以稳定8 h.讨论了测定中干扰物质中的影响及机理包括循环伏安图,温度系数,表面活性剂的影响和电毛细管曲线.结果降低了检测下限.  相似文献   

10.
合成了新显色剂2,6-双偶氮-[4,4’-(双间苯二酚)]苯并[1,2-d:4,5-d’]二噻唑(简称BABRBBT),研究了它与铜(Ⅱ)的显色反应.在Triton X-100存在下,pH 10.4的硼砂-氢氧化钠缓冲介质中,试剂与铜形成稳定的紫色络合物,其最大正吸收峰位于635 nm处,负吸收峰位于520 nm处.体系表观摩尔吸光系数为1.55×105L/mol·cm,铜的浓度在0~25 μg/25 mL范围内符合比尔定律.该方法灵敏度高,选择性好,用于实际样品中微量铜的测定,结果满意.  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.
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   

15.
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   

16.
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   

17.
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   

18.
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   

19.
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of  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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