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1.
基于脱氧核糖核酸(DNA)在pH 3.51~4.49的介质中对有机染料次甲基蓝(MB)的共振光散射的增强效应,提出了一种测定DNA的共振光散射法,并对介质酸度、离子强度、DNA热变性、共存物质干扰等实验条件进行了优化.在最佳条件下绘制了工作曲线,该方法线性范围为0~1 440 ng.mL-1,检出限可达14.1ng.mL-1,用于合成样品中DNA的测定,结果令人满意.通过研究红外光谱、紫外-可见吸收光谱及离子强度的影响,初步探讨了MB与DNA相互作用的机理,MB可能是通过静电作用等以DNA为模板在DNA分子表面进行聚集和长距组装,这种聚集导致MB共振光散射信号的增强,这也是该方法的理论基础.  相似文献   

2.
氧化钛纳米晶溶胶作为共振光散射探针检测L-酪氨酸   总被引:1,自引:0,他引:1  
以自制粒径约6 nm的氧化钛纳米晶与L-酪氨酸结合后对共振光散射有增敏作用为基础,建立了以TiO2纳米晶溶胶为探针的共振光散射法检测溶液中L-酪氨酸的方法. 考察了pH、超声时间、静置时间、纳米晶浓度和干扰组分对测定的影响. 酪氨酸浓度在0.5~4.0×10-6 g·mL-1 范围呈现较好的线性, 工作曲线的回归方程为ΔIRLS=640.9c+163.4,r=0.993,检出限为1.0×10-7 g·mL-1. 测定了复方氨基酸注射液(18AA)中酪氨酸的含量, 回收率为(99.5~102.0)%,相对  相似文献   

3.
在弱酸性条件下,核固红,Cu(Ⅱ)与盐酸吡硫醇共存时,导致体系共振光散射强度明显增强.据此建立了测定盐酸吡硫醇的共振光散射分析法.在最佳条件下,Cu(Ⅱ)-核固红-盐酸吡硫醇体系的最大散射峰位于364nm处.共振光散射增强的程度与盐酸吡硫醇的浓度在0.5~11.5μg.mL-1之间呈良好的线性关系.方法的检出限为1.5×10-2μg.mL-1.将方法用于片剂中盐酸吡硫醇的测定,并与药典法进行对照,经t检验证明2种方法无显著性差异.  相似文献   

4.
研究了脱氧核糖核酸(DNA)与阴离子染料固黄O(FYO)及阳离子表面活性剂溴化十六烷基三甲铵(CTMAB)三元体系的共振光散射光谱的特征.考察了各种影响因素,在优化条件下确立了共振光散射强度与鱼精DNA和小牛胸腺DNA以及变性后的鱼精DNA和小牛胸腺DNA浓度之间的关系,相应的线性范围分别为0.026~7.00 mg/L;0.025~7.00 mg/L;0.032~6.00 mg/L;0.031~8.00 mg/L,相关系数为0.999 1;0.999 6;0.998 1;0.999 6,检出限分为7.0,6.0,11.0,12.5 μg/L,基于共振光散射的增强,建立了一种测定DNA的新方法.图6,表4,参8.  相似文献   

5.
建立同时快速测定2,3-苯并芴、苯并[a]芘和苝3种多环芳烃的同步荧光法.选择波长差Δλ=26 nm,只需一次扫描,就可实现3个组分的同时鉴别和定量测定.2,3-苯并芴、苯并[a]芘和苝的线性范围分别为0.02~50 ng·mL-1、0.05~200 ng·mL-1和0.1~400 ng·mL-1,检出限分别为0.003 5ng·mL-1、0.002 1 ng·mL-1和0.006 0 ng·mL-1.该方法简单快速,灵敏度高,线性范围宽,用于各种实际水样的分析,获得很好的效果.  相似文献   

6.
以六氨合钴(Ⅲ)为探针的DNA共振光散射分析   总被引:1,自引:1,他引:0  
在pH为1.81~4.1的Britton-Robinson(BR)缓冲溶液中,[Co(NH3)6]3+与脱氧核糖核酸(DNA)相互作用并使其共振光散射强烈的增强.在342.0 nm处增强的共振光散射(RLS)强度与DNA的质量浓度在0.01~7.0 mg/L范围内呈良好的线性关系.据此建立了操作简便、灵敏度高的测定痕量DNA的新方法.该方法用于检测小牛胸腺DNA,检出限达到1.6μg/L级.  相似文献   

7.
在pH=7.8的Tris-HCl缓冲液中,DNA可使铽-水杨酸-邻菲罗啉三元配合物共振光散射强度显著增强,在λ=351 nm处共振光散射强度(⊿ I)与DNA浓度具有良好的线性关系.方法的线性范围为0.16~1.2μg·ml-1,检出限为0.068μg·ml-1,RSD为1.82%~2.41%,加标回收率为92.0~106.0%.  相似文献   

8.
中性红用于痕量DNA测定   总被引:2,自引:0,他引:2  
在pH 7 6~ 7 8和低离子强度条件下 ,中性红 (NR)与DNA作用产生以 53 5 0nm和 3 50 0nm为特征的共振光散射增强 (ERLS)光谱 .研究表明 ,在最佳条件下 ,在 53 5 0nm处的共振光散射增强与DNA的浓度成线性关系 ,据此建立了用ERLS光谱测定痕量DNA的新方法 .方法的检出限在纳克级 .  相似文献   

9.
共振光散射法测定镉的应用研究   总被引:4,自引:3,他引:1  
在十二烷基硫酸钠(SLS)存在的条件下,基于KI和Cd(II)形成[CdI4]2-络阴离子后与四丙基溴化铵(TPAB)结合形成离子缔合物使共振光散射(RLS)信号强度明显增强,建立了运用共振光散射技术测定水样中镉含量的新方法.研究了四丙基溴化铵-碘化钾-镉体系的共振光谱特征,在364 nm处体系的散射光强度最大.在最佳实验条件下,体系的共振光散射强度与Cd(II)浓度在0.08~4.0μg.mL-1范围内呈良好的线性关系,检出限可达2.80ng.mL-1.用此方法测定合成水样中的Cd(II),操作简便快速,回收率在96.4%~105.7%之间,结果令人满意.  相似文献   

10.
在pH10.23的Tris-HCl缓冲溶液中,阴离子主体小分子对羟基萘酚兰二钠盐(HNB)对阳离子表面活性剂十六烷基三甲基溴化铵(CTMAB)与脱氧核糖核酸(DNA:fsDNA、ctDNA)的共振光散射光谱有协同增强作用.考察了共振光散射(RLS)光谱的影响因素,在优化条件下共振光散射强度增加值(ΔI)与DNA浓度之间呈良好的关系,据此建立了一种测定DNA的新方法,该方法具有反应速度快(只须1min)、稳定性好、灵敏度高等特点.对于fsDNA、ctDNA的线性范围分别为0.05~2.5 mg/L,0.04~2.0 mg/L,检出限分别为25.9 ng/mL,24.9 ng/mL.用于fsDNA合成样测定效果较好.  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.
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   

15.
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   

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.
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   

19.
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   

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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