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 62 毫秒
1.
在酸性条件下,盐酸洛美沙星对Ce(IV)-Na2SO3微弱化学发光体系具有很强的增敏作用,据此建立了测定盐酸洛美沙星的新方法.该方法对盐酸洛美沙星的检出限为0.005 0 mg.L-1,线性范围是0.01~10.0 mg.L-1,相对标准偏差(n=10,C=1.0 mg.L-1)为1.1%,对盐酸洛美沙星的两种胶囊的测定结果较为满意,回收率在96%~106%之间.  相似文献   

2.
基于H2O2催化TB—Cr(Ⅵ)褪色反应,建立了测定Cr(Ⅵ)的方法.该方法简单快速,线性范围在0~0.624mg.L-1,标准偏差为S=0.014(n=11),用于模拟试样回收率测定,回收率在97.6%~98.6%.  相似文献   

3.
表面活性剂增敏分光光度法测定L-色氨酸   总被引:1,自引:0,他引:1  
采用分光光度法测定Trp-NO2-体系的吸收光谱行为,加入表面活性剂Triton X-114胶束后,溶液的吸光度增大,体系得到增敏,由此建立一种快速简便测定L-色氨酸含量的方法.结果表明:色氨酸量在0.2~34.0 mg.L-1范围与其吸光度呈线性关系,其直线回归方程为A=0.777ρ-0.011 9,相关系数r=0.994,检出限为0.054 mg.L-1.该方法具有灵敏度高、操作简捷的优点.在优化参数条件下对粮食等多种样品中的L-色氨酸进行分析,结果令人满意.  相似文献   

4.
方波阳极溶出伏安法测定饮料中Pb   总被引:1,自引:0,他引:1  
建立了测定饮料中Pb的新方法.在0.1mol.L-1KCl溶液(pH=2.25)中采用方波阳极溶出伏安法测定Pb.Pb于-588mV产生溶出峰,Pb测定精密度RSD%为0.5%~5.0%,样品加标回收率P%为95.42%~104.5%,Pb的线性范围为0.006~0.4mg.L-1.该法操作简便、快速,结果可靠.  相似文献   

5.
氟罗沙星在胶束体系中的荧光特性研究及应用   总被引:3,自引:0,他引:3  
目的:研究氟罗沙星在胶束体系中的荧光特性及应用.方法:用日立F-3010型荧光分光光度计测定,测定波长eλx=290 nm,eλm=450 nm,测定时最佳pH值范围为4.5~5.5.在表面活性剂十二烷基硫酸钠(SDS)存在下,由于胶束的生成,使氟罗沙星(FLRX)自身荧光大大增强,据此建立了在SDS胶束体系中测定氟罗沙星的新方法.结果:氟罗沙星浓度在0~0.9μg/mL范围内与荧光强度呈线性关系,相关系数0.9991,检测限为0.01μg.mL-1.加标回收率为97.1%~102.5%,相对标准偏差为1.5%~3.6%.结论:该方法简便,快速,可直接用于药物制剂中氟罗沙星含量的测定.  相似文献   

6.
建立同时测定加味逍遥口服液中栀子苷、芍药苷和丹皮酚含量的RP-HPLC法.采用Inertsil(ODS C18柱(4.6 mm×250 mmi.d.5μm)以乙腈-水梯度洗脱,流速1 mL.min-1,柱温20℃,检测波长235nm.结果表明栀子苷、芍药苷和丹皮酚的线性范围分别为2.25~38.25 mg.L-1、1.69~4.96 mg.L-1和0.585~17.55 mg.L-1;栀子苷的加样回收率平均为98.7%(RSD=2.15%);芍药苷的加样回收率平均为99.79%(RSD=0.31%);丹皮酚的加样回收率平均为98.86%(RSD=2.41%).该法用于同时测定加味逍遥口服液中栀子苷、芍药苷和丹皮酚的含量,该方法具有简便、快速、准确等优点.  相似文献   

7.
本文利用荷移光谱法研究了四氯苯醌与异烟肼的反应 ,确定了反应条件 ;在乙醇介质中 ,四氯苯醌与异烟肼络合物的最大吸收波长为 4 80 nm,表观摩尔吸光系数为 1.0× 10 3L· mol- 1 · cm- 1 ,异烟肼水溶液的浓度在0 .0 0 2 mg L- 1 ~ 0 .2 mg L- 1 范围内符合朗比定律。该方法重现性好 ,灵敏度高 ,精密度高 ,方法相对标准偏差为 1.3%。 (n=8)。用于测定异烟肼药片中异烟肼的含量 ,简单易行。  相似文献   

8.
应用电感耦合等离子体发射光谱(ICP-AES)法,对硅铝铁合金中的Al,Fe,Ca,Cr,Mn,Ni,Si,Ti元素进行测定.研究了ICP-AES的操作条件和溶样方法,确定了适宜的实验条件,使用该方法测定硅铝铁合金中上述元素,标准钢样测定结果与推荐值相符.对各种元素的检出限分别为Al(0.029 mg·L-1),Fe(0.004 mg·L-1),Ca(0.007 5 mg·L-1),Cr(0.001 5 mg·L-1),Mn(0.000 9 mg·L-1),Ni(0.0027mg·L-1),Si(0.045 mg·L-1),Ti(0.003 mg·L-1),对所测元素,测定结果的相对标准偏差(n=6)在0.64%~3.16%之间,加标回收率在98%~103.8%范围.测定样品中高含量硅的结果与标准化学(重量)法的结果也相符(相对误差<2%).本文方法具有简便易行和便于推广的特点.  相似文献   

9.
在缓冲液HAc-NaAc(pH=3.85)中盐酸吡硫醇可与刚果红络合生成颜色与刚果红不同的络合物,且络合物在576nm处有最大吸收,基于此建立了测定盐酸吡硫醇含量的新方法.盐酸吡硫醇浓度在0.1~45mg.L-1范围内与吸光度呈现良好的线性关系.回归方程为ΔA=0.00 618+0.02 216C(mg.L-1),线性相关系数R=0.999 7,检出限为0.03mg.L-1.该方法简便、快速、选择性好、灵敏度高,用于药物中盐酸吡硫醇的测定,测定结果与药典方法一致.  相似文献   

10.
研究了在微乳液介质中,在pH=3.5的HAc-NaAc缓冲溶液中,用硫脲作活化剂,铊(Ⅲ)催化亚铁氰化钾和4,7-二苯基-1,10-邻菲咯啉之间配体交换反应,从而建立测定痕量铊的新的催化动力方法。在530 nm处,表观摩尔系数为9.07×105L.mol-1.cm-1,铊(Ⅲ)的含量在0~80μg.L-1范围内,符合比耳定律,对反应各种因素和共存离子的影响进行了研究。该方法用于多种样品中痕量铊的测定,结果满意,其回收率在95%~105%之间,相对标准偏差小于5%。  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.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

14.
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   

15.
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   

16.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

17.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

18.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

19.
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   

20.
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   

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