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1.
和厚朴酚在0.1mol·L^-NH3-NH4Cl底液中,出现一灵敏吸附伏安还原峰,Ep=-0.23V(vs.Ag/AgCl)。当富集时间为3min时,峰电流与和厚朴酚浓度在1.0×10^-8 ̄1.0×10^-7mol·L^-1范围内呈线性关系,检测限为3.0×10^-9mol·L^-1,可用于中药厚朴的测定。  相似文献   

2.
芦荟甙的伏安行为及其应用研究   总被引:1,自引:1,他引:0  
芦荟甙在0.05mol·L^-1硫酸溶液中出现一灵敏的吸附伏安峰,峰电位为0.23V(vs.Ag/Cl)。峰电流与芦荟甙的浓度在2.0×10^-8~4.0×10^-7mol·L^-1和4.0×10^-7~6.0×10^-6mol·L^-1范围内成线性关系,检出限为5.0×10^-9mol·L^-1(富集时间为150s)。用线性扫描和循环估安法研究了体系的电化学行为,并应用于芦荟原胶中芦荟甙的的测定  相似文献   

3.
本文用分光光度法测定了显色剂5-(4-磺基-1-萘偶氮)-8-羟基喹啉的离解常数,并研究了该显色剂与Yb的络合情况。结果表明,在pH为2-12之间,该显色剂共有三种存在形式:H2L(NH^+)、HL^-、L^2-,它的离解常数为Ka1=1.61×10^-5,Ka2=4.10×10^-9,在pH=9.60附近,该显色剂可与Yb^3+形成3:1、2:1、1:1的配合物。  相似文献   

4.
以石墨电极为基体制成碳糊电极,研究了马钱子碱在该电极上的测定方法,在0.01mol·L^-1H2SO4底液中,选择阳极电位为0.35V,峰电流与马钱子碱的浓度在1.0×10^-7-1.0×10^-4mol·L^-1范围内呈良好的线性关系,该法的检测下限为5.0×10^-8mol·L^-1,回收范围为95.8-105.9%中变量的取值和相对标准偏 3.3%。本方法准确、快速、简便。  相似文献   

5.
研究了次黄嘌呤在铜电极上的电化学行为。实验发现,以1.96×10^-3 ̄4×10^-4mol·L^-1NaOH作支持电解质时,在-0.25 ̄-0.40V的电位范围内有一灵敏的阴极峰,它是吸附于铜电极表面的Hxa与Cu^+络合物的溶出伏安峰,在选择的实验条件下,峰高与Hxa的浓度在1.46×10^-6 ̄2×10^-3mol·L^-1范围内呈良好的线性关系,最低检测限为5.6×10^-8mol·L^-  相似文献   

6.
在pH4.5缓冲溶液中,安眠酮在-1.17V处产生一灵敏吸附极谱波,利用此波可测定微量安眠酮,线性范围为1.0×10^-7 ̄1.0×10^-6mol·L^-1,检测下限为9.0×10^-8mol·L^-1,所提出的方法用于片剂及血清中安眠酮的测定,结果满意。  相似文献   

7.
研究了温度、酶浓度、反应时间、几种有机溶剂等因素对PstⅠ星号活力的影响,并在有利于星号活力的反应条件下测定了星号活力及原活力的Km分别为1.46×10^-7mol/L和1.02×10^-8mol/L,Vmax分别为2.86×10^-18mol/s和3.06×10^-15mol/s。  相似文献   

8.
通过一系列滴定量热测定,求得了298.15K时十二钨硅酸及其6DMF、8DMSO加合物的标准生成焓,其数值分别为-(13.14±0.01)×10^3KJ·mol^-1、-(13.61±0.01)×10^3KJ·mol^-1及-(13.86±0.01)×10^3KJ·mol^-1。  相似文献   

9.
细胞显微电泳表明,介质PH值对离体玉米精细胞电泳迁移率有较大影响,在HClGly(甘氨酸)缓冲液中,其等电点介于PH2.4-3.0;在PH6.7的MES缓冲液中,电泳后统计分析表明,离体玉米精细胞可以区分为电泳迁移率有差异的2种类型,其电泳迁移率分别为(1.803±0.043)×10^-6和(1.667±0.052)×10^-6m^2.V^-1.s^-1。根据电泳迁移率的差异,利用一种支无持细胞电  相似文献   

10.
研究了导数示波极谱法测定大气中微量的二硫化碳。在0.6900mol.L^-1乙醇0.0970mol.L^-1二乙胺-0.001 5mol.L^-1EDTA底液中,二硫化碳产生一灵敏的峰电流。峰电位为-0.64V(vs.SCE).二硫化碳浓度在1.00×10^-8mol.L^-1-3.00×10^-5mol.L^-1范围内,浓度与峰电流具有线性关系。检测限为1.00×10^-8mol.L^-1.用本  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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