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1.
在硫酸介质中,在溴酸钾氧化罗丹明B的反应体系中,加入Cu(Ⅱ),能加速反应的进行,Cu(Ⅱ)对此褪色反应有催化作用,据此建立了测定微量铜的催化动力学荧光法.研究了影响催化褪色反应速度的最佳条件,在最优化条件下,Cu(Ⅱ)浓度在8×10~(-8)μg/mL~2×10~(-6)μg/mL范围内与荧光强度呈良好的线性关系,其相关系数为0.998 0,方法的检出限为2×10~(-8)μg/mL.对浓度为1×10~(-7)μg/mL的Cu(Ⅱ)标准溶液进行11次平行测定,得相对标准偏差(RSD)为1.2%,该法简单、快速、灵敏度高,已应用于自来水、茶叶中Cu(Ⅱ)含量的测定,回收率为96.3%~104.3%,结果令人满意.  相似文献   

2.
研究了铜(Ⅱ)催化H2O2氧化7-(5-羧基-1,3,4-三氮唑偶氮)-偶氮氯膦(CTACPA)的褪色反应,褪色反应程度与铜(Ⅱ)量在一定范围内呈线性关系,建立了测定痕量铜(Ⅱ)的催化动力学光度法.在pH 4.0的HAc-NaAc缓冲溶液中,褪色体系的最大吸收波长535 nm,铜(Ⅱ)的质量浓度在(0.004 ~0.2)μg/mL范围内符合线性关系.回归方程为△A=3.026 0ρ-7.24×10-3(ρ:μg/mL),相关系数r=0.999 4,检出限为2.90×10-10 g/mL.方法不经分离直接测定头发和河水中的痕量铜,测定结果与AAS法的测定值相符.  相似文献   

3.
Co(Ⅱ)-KIO4-乙基紫体系催化光度法测定痕量钴   总被引:1,自引:0,他引:1  
基于在pH=4.50的HAc-NaAc的缓冲溶液体系中,在F-存在下Co(Ⅱ)对KIO4氧化乙基紫褪色有明显催化作用,建立了测定Co(Ⅱ)的方法.该方法灵敏、快速、操作简便,最大吸收波长在598nm处,该方法的检出限为2.48×10-8g/mL,线性范围为0.08-0.64mg/mL.  相似文献   

4.
在Cu(Ⅱ)存在下,研究了luminol-Cu(Ⅱ)-盐酸二甲双胍化学发光体系,建立了测定盐酸二甲双胍的流动注射化学发光新方法.结果表明,在优化的实验条件下,化学发光强度与盐酸二甲双胍浓度在1.0×10-9~1.0×10-7g/mL范围内呈线性关系.该方法测定盐酸二甲双胍的检出限为5×10-10g/mL,相对标准偏差为1.1%(1.0×10-8g/mL盐酸二甲双胍溶液,n=11).该方法已用于片剂中盐酸二甲双胍含量的测定.  相似文献   

5.
研究了催化动力学褪色光度法测定痕量铜(Ⅱ)的新体系,反应介质为NH3·H2O-NH4Cl缓冲溶液(pH=10.0),催化体系为痕量Cu(Ⅱ)催化H2O2氧化茜素的褪色反应.考察了反应体系的适宜条件、动力学性质及28种干扰离子的影响,建立了一种催化动力学光度法测定痕量铜的新指示反应.本法的线性范围为0~1.2×10-7 g/mL,其灵敏度远远高于普通光度法,检出极限为1.76×10-10g/mL,可应用于农产品和蒙药中铜的测定,相对标准偏差为1.1%~3.2%.  相似文献   

6.
过氧化氢-橙黄催化动力学光度法测定痕量钴的研究   总被引:1,自引:0,他引:1  
在pH=9.53的NH3-NH4Cl缓冲溶液介质中,痕量Co2+对H2O2氧化橙黄G(OG)的褪色反应具有显著的催化作用,据此建立了催化动力学光度法测定痕量Co2+的新方法,该方法的线性范围为0.006~2.000μg/25 mL,检出限为3.41×10-3μg/25 mL,可直接用于维生素B12针剂中痕量Co2+的测定,结果满意.  相似文献   

7.
陈国树  揭辉 《江西科学》2002,20(4):257-259
在硫酸介质中,痕量铜(Ⅱ)能灵敏地催化高碘酸钾氧化靛红La褪色。系统地研究了指示反应的最优化实验条件,建立了测定痕量铜(Ⅱ)的新方法。方法检出限为4×10-12g/ml铜(Ⅱ)。方法检测范围0~0.1μg铜(Ⅱ)/25ml。用以测定矿泉水中的痕量铜(Ⅱ),获得了较好的结果。  相似文献   

8.
催化光度法测定痕量钴--Co(Ⅱ)-茜素红-溴酸钾体系   总被引:1,自引:0,他引:1  
研究了pH为8.0时的氨-氯化铵介质中,Co(Ⅱ)催化溴酸钾氧化茜素红褪色,建立了动力学光度法测定痕量Co(Ⅱ)的新方法.本方法检出限为4.4×10-6g/L,线性范围0~0.15mg/L,实测了天然水中痕量钴,结果满意.  相似文献   

9.
PC-88A-煤油-HCl分散支撑液膜中Co(Ⅱ)的传输研究   总被引:2,自引:0,他引:2  
以聚偏氟乙烯膜(PVDF)为支撑体,煤油为膜溶剂,2-乙基己基膦酸-单-2-乙基己基酯(PC-88A)为流动载体,研究了分散支撑液膜体系中金属Co(Ⅱ)的传输行为;考察了料液相pH、分散相中液膜相(0.081mol/L PC-88A/煤油)与解析相(HCl溶液)体积比、解析相中HCl浓度、Co (Ⅱ)初始浓度对Co(Ⅱ)传输的影响.结果表明,用HCl作解析剂,料液相pH=6.0、液膜相与解析相体积比为160:40、解析相中HCl浓度为4.0mol/L时,该分散支撑液膜体系对金属Co(Ⅱ)具有最佳传输.在最佳传输条件下,起始浓度为3.0×10-4mol/L时,190min,Co(Ⅱ)传输率可达到94.4%,而传统支撑液膜只能达到62.6%.从界面化学和扩散传质角度提出了金属离子的传输动力学方程,采用直线斜率法对Co(Ⅱ) 在分散支撑液膜体系中的扩散层厚度(δa=1.67×10-4m)和扩散系数(d0=8.99×10-11m2/s)进行了测定,取得满意结果.  相似文献   

10.
基于pH=9.0的NH3-NH4Cl缓冲液中与T=40℃的条件下,Co(II)催化过氧化氢氧化茜素红的褪色反应,建立了催化过氧化氢氧化茜素红褪色光度法测定痕量Co(II)新方法,对测量波长、试剂浓度、反应温度、反应时间及共存离子的干扰等条件进行探讨和选择.该催化褪色反应的速率常数k=2.70×10-4S-1,表观活化能E=96.79KJ/mol.Co(II)含量在0.50~5.2μg/L范围内符合比尔定律,其线性回归方程为㏒(A0/Ai)=0.0138CCo(II)(μg/L)–0.0003,r=0.9994,检出限为0.33μg/L(3Sb/k,n=11).本方法已成功用于叶绿素钴盐样品中Co(II)含量的测定,回收率为102.1~102.6%.  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.
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   

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 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   

15.
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   

16.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

17.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

18.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

19.
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   

20.
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   

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