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1.
西咪替丁的线性扫描极谱法测定   总被引:1,自引:0,他引:1  
用线性扫描极谱法研究了西咪替丁的电化学行为.在0.16 mol·L-1Na2HPO4-KH2PO4缓冲溶液(pH6.65)中,西咪替丁于-1.903V(vs.SCE)处产生一灵敏的吸附波,其一次线性扫描极谱峰电流与西咪替丁浓度在4.0 mg·L-1-200.0 mg·L-1范围内呈良好的线性关系,相关系数r=0.9935(n=10),检出限为2.0 mg·L-1.对80.0 mg·L-1西咪替丁溶液进行6次平行试验,RSD为0.86%,回收率在94.7%-99.4%之间.本方法操作简便、准确、结果重现性好,可用于胶囊中西咪替丁含量的测定.  相似文献   

2.
用线性扫描极谱法和循环伏安法研究克拉霉素在0.15mol·L-1Na2HPO4-KH2PO4缓冲溶液(pH6.86)中的电化学行为,克拉霉素于-0.740V(vs.SCE)处产生一灵敏的还原波,克拉霉素浓度为0.08mg·L-1~100.0mg·L-1范围内,其一次微分线性扫描峰电流与克拉霉素浓度呈良好的线性关系,相关系数r=0.99656(n=5),检出限为0.06mg·L-1。对4.0mg·L-1克拉霉素溶液进行6次平行试验,RSD为2.33%,回收率在94.88%~105.36%之间。方法可用于其在片剂中含量的测定。  相似文献   

3.
用线性扫描极谱法和循环伏安法研究替米沙坦在0.25mol·L-1Na2HPO4-KH2PO4缓冲溶液(pH7.56)中的电化学行为,替米沙坦于-0.449V(vs.SCE)处产生一灵敏的吸附波,在替米沙坦浓度为0.2mg·L-1~20.0 mg·L-1范围内,其一次微分线性扫描峰电流与替米沙坦浓度呈良好的线性关系,相关系数r=0.99523(n=10),检出限为0.1 mg·L-1。对20.0mg·L-1替米沙坦溶液进行6次平行试验,RSD为0.76%,回收率在98.8%~105.9%之间。方法可用于其在片剂中含量的测定。  相似文献   

4.
红霉素(EM)、阿奇霉素(AM)和琥乙红霉素(EEM)与稀H2SO4作用生成棕色化合物,最大吸收波长均在482 nm处,表观摩尔吸光系数(ε)在1.36×104~1.76×104L.mol-1.cm-1之间,不同体系的线性范围从0~22.0至0~34.5 mg/L.红霉素及其衍生物在一定浓度范围内遵从比耳定律,由此建立了快速测定其含量的分光光度法,并探讨了适宜的反应条件、主要分析化学性质、方法的精密度和可靠性.该法用于市售红霉素及其衍生物的含量测定,结果满意.  相似文献   

5.
毛细管电泳-电化学发光联用测定琥乙红霉素   总被引:2,自引:0,他引:2  
 基于琥乙红霉素对联吡啶钌(Ru(bpy)32+)电化学发光的增强作用,结合高效毛细管电泳分离技术,建立了一种毛细管电泳-电化学发光联用检测琥乙红霉素的新方法。分别对分离和检测条件进行了优化。优化条件下,琥乙红霉素的线性范围为0.7~10.0 μmol/L,检测限为0.23 μmol/L,峰高相对标准偏差RSD为4.1%。采用堆积放大进样技术可进一步提高检测灵敏度。本方法用于生物体液中琥乙红霉素的测定,回收率为81.3%~93.0%。  相似文献   

6.
濒危植物延龄草愈伤组织诱导研究   总被引:6,自引:0,他引:6  
通过延龄草愈伤组织诱导研究发现,延龄草根茎所产生的愈伤组织在1/2 MS BA(苄基氨基嘌呤)1.2 mg.L-1 IAA(吲哚乙酸)0.6 mg.L-1培养基中较好,诱导频率为83.33%;在1/2 MS BA 1.2 mg.L-1 IAA 1.2 mg.L-1培养基中次之,诱导频率为66.67%;在1/2 MS BA 1.2 mg.L-1 IAA 0.2 mg.L-1培养基中也能产生,但质地较差,诱导频率为22.22%;在1/2 MS BA 1.2 mg.L-1 NAA(萘乙酸)0.2mg.L-1培养基中也能产生少量.可见,以1/2 MS作为基础培养基,加入1.2 mg.L-1BA和0.6 mg.L-1IAA,以根茎为外植体进行延龄草组织培养,能产生大量的愈伤组织.研究表明,利用组织培养繁殖延龄草是一种有效、可行的途径.  相似文献   

7.
以黄独无菌试管苗为材料,采用单因子实验,对NAA对黄独试管苗生长发育和离体保存进行了初步的研究。结果表明:(1)0.5-1mg.L-1NAA可促进黄独的生长发育,2-4mg.L-1NAA则抑制黄独的生长发育;(2)1mg.L-1的NAA对根的数量、茎的长度和叶的数量与大小均有促进作用,但对根粗和茎粗有抑制作用;(3)2-4mg.L-1NAA可促进愈伤组织形成,在2mg.L-1的NAA作用下愈伤组织最大平均直径为2.6cm,多为白色;(4)0.5-1mg.L-1NAA不利于黄独的离体保存,而2-4mg.L-1NAA可提高黄独试管苗离体保存的成活率。  相似文献   

8.
通过微生物-类Fenton氧化联合技术提高水溶液中萘的降解.实验结果表明:投加量为200 mg·L-1的50 mL萘溶液经纺锤芽孢杆菌(BFN)降解96 h后,萘的去除率达100%,而溶液中COD的去除率仅为59.4%,说明溶液中还存在萘的降解中间产物.在纳米零价铁(nZVI)投加量为1.0 g·L-1,H2O2为10mmol·L-1,pH为3.0,温度35℃的优化条件下,对BFN降解40 h后的溶液进行类Fenton氧化,溶液COD的去除率达到86.7%.最终,微生物-类Fenton氧化联合法对200 mg·L-1萘溶液的COD总去除率高达91.6%.  相似文献   

9.
用线性扫描极谱法研究瑞格列奈的电化学行为.在0.1 mol·L-1 Na2HPO4-KH2PO4缓冲溶液(pH6.86)中,瑞格列奈于-1.180 V(vs.SCE)处产生一灵敏的吸附波.在5.0~500.0μg·L-1范围内,其一次微分线性扫描峰电流与浓度呈良好的线性关系,相关系数r=0.9984(n=10),检出限为3.5μg·L-1.以50.0μg·L-1瑞格列奈溶液作6次平行试验,RSD为0.83%,回收率在97.4%~107.6%之间.该法可用于片剂中瑞格列奈含量的测定.  相似文献   

10.
采用硫化铵快速分解硫磺试样,在16.56 mol·L-1NH3·H2O-0.21 mol·L-1酒石酸钠-3.01×10-4mol·L-1Pb-1.50×10-2mol·L-1EDTA-0.12mol·L-1Na2SO3-3.2×10-4mol·L-1HNO3体系中以催化极谱法测定微量碲.极谱峰电位为-1.10V(VS·SCE).碲浓度在4~100ng/mL-1范围内与峰电流有良好的分段线性关系.检出下限为4ng·mL-1.方法的RSD为1.9%~2.3%,加标回收率为90.10%~96.00%.该法操作简便快速,用于硫磺样品的测定结果满意.  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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