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1.
建立了用荧光光谱研究多西环素与β-环糊精形成包合物的荧光光谱特性的方法.对多西环素与β-环糊精形成包合物的条件、作用机理进行了研究,探讨了可能的包合方式,测定了包合物的包合常数.实验结果表明:pH10.90的NH3-NH4Cl介质中β-环糊精与多西环素能包合生成1:1的包合物,可显著增强多西环素的荧光强度,据此建立了测定药物制剂中多西环素的新方法.多西环素浓度在4.7×10-7mol·L-1~9.4×10-6mol·L-1范围内,与体系荧光强度呈现良好的线性关系,相关系数r=0.9943,检测限为1.1×10-7mol·L-1,对药物制剂中多西环素的含量进行了测定,测定结果与标示量吻合,回收率在98.5%~100.3%之间.  相似文献   

2.
用葡萄糖-丙酮-MnSO4-KBrO3-H2SO4,双有机底物化学振荡体系测定了L-蛋氨酸和D-蛋氨酸.结果表明,当L-蛋氨酸浓度为7.5×10-7~1.0×10-5mol·L-1,D-蛋氨酸浓度为4.0×10-6~2.3×10-5mol·L-1时,体系周期的变化量与所加入蛋氨酸浓度的负对数呈良好的线性关系.同时讨论了温度与反应底物对测定的影响,并用本法成功地测定了血液及饲料中的蛋氨酸,回收率为98.1%~101.1%.  相似文献   

3.
在碱性介质中,Cu2+对鲁米诺-盐酸羟胺的化学发光有明显的增敏作用,而PO3-4能与Cu2+反应生成Cu3(PO4)2沉淀,对Cu2+增敏的鲁米诺-盐酸羟胺的化学发光有抑制作用,据此建立测定洗衣粉中PO3-4的流动注射化学发光分析方法.在1.0×10-10~1.0×10-7 mol·L-1范围内,洗衣粉中PO3-4的浓度与相对发光强度有良好的线性关系,线性方程为△I=214.6 +214.6c,线性相关系数为0.999 3,检出限为1.0×10-12mol·L-1.对1.0×10-7mol·L-1的PO3-4进行11次平行测定,其相对标准偏差为1.3;.此方法用于测定洗衣粉中磷的含量,结果令人满意.  相似文献   

4.
在pH7.00的NH4Ac-NH3·H2O的缓冲溶液中,四环素与铕(Ⅲ)生成二元配合物并发射出铕(Ⅲ)位于612nm处的特征荧光.加人2,6-二乙氧摹-β-环糊精后,体系的荧光强度显著增强,且增强的荧光强度与四环素的浓度成正比.在最佳实验条件下,测定四环索的线性范围是3.64×10-7-1.60×10-5 mol·L-1,检出限为1.10×10-7mol·L-1.研究了共存物质的影响,该方法成功地用于血样和尿样中四环素的测定,结果令人满意.  相似文献   

5.
基于碱性介质中精氨酸对鲁米诺-铁氰化钾化学发光体系有增敏作用的事实,建立了毛细管电泳-化学发光法鉴定L-精氨酸纯度的新方法.优化发光条件为:缓冲溶液为2.5×10-3mol.L-1硼砂含2×10-3mol.L-1鲁米诺,氧化试剂为2×10-4mol.L-1铁氰化钾(用氢氧化钠调节pH值为13.3).在保证L-精氨酸与其产品中的杂质基线分离的情况下,得到L-精氨酸的线性范围为0.001 43~0.143 mol.L-1,检出限(S/N=3)为1.43×10-3mol.L-1.通过对来源不同的三种L-精氨酸标准样品进行分析,效果令人满意.  相似文献   

6.
采用循环伏安法直接制备了石墨烯修饰玻碳电极并对其进行了表征,研究了亚硝酸根在石墨烯修饰玻碳电极上的电化学行为.研究结果表明:石墨烯修饰电极对亚硝酸根的氧化有良好的电催化活性,在0.10 mol·L-1PBS缓冲液(pH值为7.0)中动态安培法检测亚硝酸根的线性范围为2.69×10-6~8.13×10-4 mol·L-1和8.13×10-4~8.56×10-3 mol·L-1,灵敏度分别为42.68和10.91 μA·(mmol·L-1)-1,检出限为8.68×10-7mol·L-1(3sb).利用该方法测定了土壤样中亚硝酸根的含量,结果令人满意.  相似文献   

7.
用电化学方法在pH=13、15~18℃环境中直接测定游离S2-,灵敏、简便.实验以单线性伏安法,采用铂盘电极对S2-进行测试,结果显示,线性范围为1.00×10-5~5.00×10-4mol·L-1,检测限在1.00×10-5mol·L-1,回收率92.03%.对五个天然水体样品进行测定,其中一个样品中的S2-浓度是2.00×10-5mol·L-1,  相似文献   

8.
β-环糊精-酚酞与间硝基氯苯相互作用生成超分子包络物并引起体系光谱信号的变化,据此以酚酞与β-环糊精形成的超分子光谱探针建立了用分光光度法测定间硝基氯苯的新方法.方法的线性范围为1.0×10-4~1.0×10-3mol·L-1,检出限为9.95×10-6mol·L-1.此法操作简单、灵敏、可靠,用于废水中硝基氯苯的测定获得满意的结果.  相似文献   

9.
报道了在盐酸介质中以KBrO3-KBr-KI-淀粉为显色剂,快速测定化妆品中痕量防腐剂苯酚的紫外-可见分光光度法.在优化条件0.24 mol·L-1 HCl,3.0×10-5 mol·L-1 KBrO3,2.0×10-4 mol·L-1 KBr,0.96×10-3 mol·L-1 KI,0.036%的淀粉溶液中测定苯酚时,△A和苯酚浓度在0.05~2.5 μg·mL-1范围内呈良好的线性关系,检测下限为0.01 μg·mL-1.本法操作简便、快速、灵敏,用于实际样品洗发精的回收率试验,结果满意.  相似文献   

10.
报道了一种新的测定雌性激素的流动注射化学发光方法.在碱性条件下,金银复合纳米粒子能强烈地增强鲁米诺-过氧化氢化学发光,而天然雌性激素能明显的抑制金纳米溶胶催化的鲁米诺-过氧化氢体系的化学发光.据此,我们建立了测定天然雌激素(雌酮、雌二醇和雌三醇)的化学发光方法.在最优化的实验条件下,测定雌酮、雌二醇和雌三醇的线性范围分别为1.0×10-6-4.0×10-8,1.0×10-5-1.0×10-7和1.0×10-5-7.0×10-8.检测限分别为4.3×10-9mol·L-1,3.9×10-8mol·L-1和6.5×10-9mol·L-1,相应的相对标准偏差分别为 2.7%,1.8 %和2.3%.该方法用于孕妇尿样中雌激素总量的测定,结果令人满意.  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.
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.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

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