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1.
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   

2.
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   

3.
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   

4.
顶空气相色谱法测定克拉霉素中的丙酮溶剂残留   总被引:1,自引:0,他引:1  
建立了克拉霉素中丙酮溶剂残留量的测定方法.采用顶空气相色谱法,氢火焰离子化检测器(FID),以二甲基甲酰胺(DMF)为溶剂,HP-FFAP弹性石英毛细管柱为色谱柱(30 m×0.25mm,0.25μm),氮气为载气,分流比为1:60,进样口温度为200℃,检测器温度250℃,柱温采用程序升温.丙酮的质量浓度在0.002~4 g·L-1的范围内呈良好的线性关系(r=0.999 5),回收率为99.2%(RSD=1.9%)检出限小于2.0 mg·L-1.  相似文献   

5.
用线性扫描极谱法和循环伏安法研究奥沙普秦在0.05mol.L-1HAc-NaAc缓冲溶液(pH5.18)中的电化学行为。奥沙普秦于-1.221V(vs.SCE)处产生一灵敏的吸附波,奥沙普秦浓度在4.0μg.L-1~2000.0μg.L-1范围时,其一次微分线性扫描峰电流与奥沙普秦浓度呈良好的线性关系,相关系数r=0.99920(n=15),检出限为2.4μg.L-1。对200.0μg.L-1奥沙普秦溶液进行6次平行试验,RSD为1.02%,回收率在94.3%~96.2%之间,方法可用于其在片剂中含量的测定。  相似文献   

6.
用线性扫描极谱法研究琥乙红霉素的电化学行为,在0.1 mol.L-1KH2PO4-Na2HPO4缓冲溶液中(pH7.46),琥乙红霉素于-1.6 V(vs.SCE)处产生一灵敏的氢催化波,其峰电流与琥乙红霉素浓度在10-800 mg.L-1范围内呈良好的线性关系,相关系数r=0.9959,检出限为7.5 mg.L-1。对100 mg.L-1琥乙红霉素溶液进行6次平行试验,RSD为0.53%。回收率在98.2%-100.9%之间。该法可用于测定片剂中琥乙红霉素的含量。  相似文献   

7.
在0.4mol·L-1 NH3·H2O-NH4Cl缓冲溶液中(pH=9.19),用线性扫描极谱法连续测定了红菇中Cu、Cd、Zn三种微量元素的含量.研究结果表明:Cu2 、Cd2 、Zn2 的峰电位分别为-0.45V(vs·SCE)、-0.79V(vs·SCE)、-1.33V(vs·SCE);线性范围分别为1.3×10-5~1.5×10-4 mol·L-1、2.5×10-5~5.0×10-4mol·L-1、2.5×10-5~5.0×10-4mol·L-1;检出限分别为0.006μg/mL、0.005μg/mL、0.006μg/mL,回收率分别为97.0~100.5%、98.4~102.0%、96.5~102.6%.此方法准确、简便、快速、灵敏度高.  相似文献   

8.
用线性扫描极谱法和循环伏安法研究秋水仙碱在0.2mol/L NH3-NH4Cl缓冲溶液(pH9.63)中的电化学行为,秋水仙碱于-1.304V(vs.SCE)处产生一灵敏的吸附波,在秋水仙碱浓度为0.05~10.0mg/L范围内,其一次微分线性扫描峰电流与秋水仙碱浓度呈良好的线性关系,线性回归方程为Ip=0.00310+0.29373C,相关系数r=0.99287(n=10),检出限为0.03mg/L。对5.0mg/L秋水仙碱溶液进行6次平行试验,RSD为2.10%,回收率在98.00%~102.10%之间。方法可用于片剂中秋水仙碱含量的测定。  相似文献   

9.
在0.1 mol·L-1KH2PO4-NaOH(pH=8.0)介质中,头孢吡肟在玻碳电极上产生-灵敏的氧化峰,其峰电流Ip与头孢吡肟在5.2×10-6~2.6×10-5mol·L-1内有良好的线性关系(r=0.999 6),检出限为5.13×10-9mol·L-1,回收率98.33%,RSD为2.12%.用线性扫描和循环伏安法研究了体系性质,结果表明,头孢吡肟的电极过程为具有吸附的不可逆过程,电极反应转移电子数为2.  相似文献   

10.
邻菲啰啉的电化学性质研究   总被引:2,自引:0,他引:2  
0 .5mol·L- 1 的一氯乙酸和 0 .1g·L- 1 的十二烷基磺酸钠溶液中 ,邻菲啉有一灵敏极谱峰 ,其峰电位是 -0 .75V(vs.SCE) .峰电流与邻菲啉的浓度在 4.0× 10 - 7~ 3.8× 10 - 5mol·L- 1 范围内呈线性关系 (r =0 .9985 ) ,检测下限为 2 .0×10 - 7mol·L- 1 .利用线性扫描极谱法和循环伏安法研究了邻菲啉的电化学性质  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   

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