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1.
磺化聚苯乙烯(SPS)及其离聚物的光谱特性   总被引:1,自引:1,他引:1  
取苯乙烯磺化及离子化后其红外光谱产生一系列特征变化,磺化度不同的聚苯乙烯其磺酸基团伸缩振动强度不同。磺化度的提高会引起磺化聚苯乙烯(SPS)红外光谱的分裂。本外本文还就磺化聚苯乙烯及其离聚体的二氯甲烷溶液的荧光发射谱进行了讨论,结果表明,磺化程度和离子化对聚合物的荧光发射峰的强度和位置都有一定影响。  相似文献   

2.
本文用ESR研究MgCL2-n-BuOH-i-Bu3Al-TiCl4/i-Bu3Al催化剂乙丙共聚机理。ESR谱表明烷基化Ti3+活性中心有单空配位和双空配位两种状态,在乙烯或乙丙烯混和单体存在下ESR谱变化指出g=1.954和g=1.941的共振吸收峰和活性中心有关。结合共聚产物组成及竞聚率的13C-NMR谱分析,提出镁钛系载体催化剂活性中心上乙丙同时配位的机理。  相似文献   

3.
4.
固载化酞菁铜的ESR波谱研究   总被引:3,自引:0,他引:3  
  相似文献   

5.
刘芳 《波谱学杂志》1989,6(3):341-346
本文首次制备了胰岛素氮氧自由基,研究了胰岛素探针与其受体结合过程中ESR波谱参数的动力学变化.实验表明胰岛素与其受体结合前后,膜蛋白质的构象、胰岛素分子的旋转相关时间(τc)和胰岛素氮氧自由基的ESR波谱振幅(h0)均发生明显的变化,这些变化均与胰岛素-受体的内噬现象有关系.当封闭受体上的巯基、氨基或羟基时,胰岛素与其受体的结合能力便受到一定的阻抑作用.  相似文献   

6.
测定了邻香草醛丙氨酸铜配合物在不同状态(固态或溶液)、不同溶剂(CH3OH,DMF,DMSO)及不同温度(室温和150K)下ESR波谱.室温溶液谱观察到二级效应和弛豫效应,藉自旋哈密顿给于了满意解释,由低温溶液谱波谱参数计算了配合物键参数,讨论了成键特性和配合物稳定性.  相似文献   

7.
测定了VOSO4与天冬氨酸(asp)和邻菲罗啉(phen)及联吡啶(bipy)三元体系在不同酸度(pH=1-14)的乙二醇-水(1:1)溶液中低温ESR波谱,发现不同pH下生成不同组成和结构的络合物,利用Johnson加合规则并配合IR推测了它们的可能结构,利用电子光谱数据,计算了络合物晶体场参数。  相似文献   

8.
姜小明  丁宁  赵濉 《波谱学杂志》2012,29(3):388-392
利用ESR测定了自由基探针5-doxyl stearic acid在烷基苯磺酸钠溶液中超精细偶合常数(AN)和旋转相关时间(τR). 根据AN随浓度的变化规律测定了表面活性剂的临界胶团浓度(cmc),并与表面张力法的结果作了对比. 通过分析AN和τR数据,讨论了位于磺酸根邻位的疏水短链的长度变化对胶团微极性和微粘度的影响. 结果表明,当疏水短链的碳原子数增加时,临界胶团浓度降低,胶团微极性增加,胶团微粘度降低.  相似文献   

9.
用电子自旋共振(ESR)方法对非晶Ag+离子导体0.85AgI~0.15Ag4P2O7的热处理晶化过程进行研究,在样品中掺入微量(约1×10-3 g/g)的Mn2+或V4+离子作为自旋探针离子,它们的ESR谱强度随升温线性减弱,当样品完全晶化时ESR谱消失。这样测定的样品完全晶化的温度分别为98℃(掺Mn的)和108℃(掺V的).本文还对Mn2+和V4+的ESR谱进行了分析。  相似文献   

10.
在顺磁共振(ESR)诊断恶性肿瘤的波谱信号载体研究中,经氨基酸序列及含量分析,测定人发内含有17种氨基酸,黑发与白发的氨基酸序列与含量分别为339.82±24.46μmol/g,334.24±31.66μmol/g,两者差别不明显,可见氨基酸不是ESR波谱信号的载体,但在人发和黑色素的g因子研究中[1,2],其结果证实,人发顺磁共振波谱信号的主要载体是黑色素。  相似文献   

11.
煤的ESR波谱研究   总被引:2,自引:1,他引:1  
利用JES-FE1XG型电子自旋共振波谱仪,系统地研究了褐煤与风化烟煤的ESR波谱,褐煤与风化烟煤中存在大量稳定的自由基,从褐煤到烟煤,随着煤化作用的加强,ESR波谱的吸收峰变窄,风化使烟煤的自旋浓度明显下降,这将为判断煤是否风化提出又一定量判据,其原因可能是由于风化使煤的局部大分子遭到破坏,从而影响π电子自由基的稳定性.  相似文献   

12.
Concepts and methods of ESR dating   总被引:1,自引:0,他引:1  
Martin Jonas   《Radiation measurements》1997,27(5-6):943-973
Electron spin resonance (ESR) dating is an absolute dating method suitable for the Quaternary which can be applied to a wide range of materials. It is based on determining the natural radiation dose to which a sample has been exposed during its burial period. This paper outlines the basic concepts, and reviews recent studies on the methods and models of ESR dating.

Scope of this paper. This review paper is one of two in this volume providing an overview of recent developments in the field of electron spin resonance (ESR) dating. The paper focuses on studies investigating the fundamental concepts and methods employed in ESR dating, while the companion paper by Rink (this issue) focuses on applications of the method. Previous review articles have been published by Ikeya (1978) and Ikeya (1985), Hennig and Grün (1983), Nambi (1985) and Grün (1989b). Subsequently, papers by Grün (1991), Schwarcz (1994) and Ikeya (1994a); Ikeya (1994b) and Ikeya (1994c) have reviewed specific aspects of the field. There are three books on ESR dating by Ikeya (1986), in Japanese), Grün (1989a)Grün (1989b), in German) and Ikeya (1993), in English) respectively. In view of the coverage of previous reviews of the field, this paper concentrates on research undertaken since 1990.

The first part introduces and outlines the basic ideas of ESR and its application to dating. This is followed by an overview of recent studies concerned with the basic concepts of the field, its methods and models, as independently of specific materials as possible.  相似文献   


13.
用电子自旋共振(ESR)波谱技术对受60Co辐照后的西洋参样品进行了较长时间的跟踪观测,发现γ辐射在西洋参内产生两种或两种以上的不稳定自由基,井测定了它们的衰减速率常数;当照射剂量过大时,还将出现异常稳定的自由基.这表明在西洋参内产生了永久性损伤.  相似文献   

14.
设计并研制了用于水溶液体系进行电化学激发-电子自旋共振测量的电解池。以亚甲蓝溶液和聚吡咯薄膜修饰电极的现场ESR研究为例,对该电解池的性能进行了考察。实验不仅为上述两个体系的研究提供了新的信息,而且也证明电解池设计合理、控制工作电极电位准确、响应快及灵敏度高,对研究水溶液体系电化学反应中间体、特别是现场制备和研究薄膜化学修饰电极极为有用。  相似文献   

15.
The scope of application of ESR spectroscopy has greatly expanded with the advent of its widespread use in radiation exposure dating around 1980 and its use in retrospective dosimetry since the Chernobyl disaster in 1986. Few fields of study are of such breadth that they span topics as diverse as dating of human origins, volcanic activity, cave deposits and earthquakes, while also providing prognoses for radiation accident victims. Between 1945 and 1975 ESR was mainly used to define the nature of paramagnetic defects in crystalline and amorphous materials, which laid the foundation for its use in applied areas in Quaternary geology, archaeometry and accident dosimetry. This review chronicles the development of the use of ESR in applied science since 1975, with particular emphasis on the state of the art in the period 1987–1997. The first part of the review focuses mainly on the range of applications for datable materials: tooth enamel (Section 2), calcite (Section 3) and quartz (Sections 4–9), while the second part comprises the areas of retrospective dosimetry (Section 10) and new applications (Section 11). The review concludes (Appendix A) with an introduction to the physical basis and assumptions involved in ESR dating, and compilations of valuable reference works for students and workers in this field.  相似文献   

16.
低密度聚乙烯光引发交联机理——Ⅱ.BNB自旋捕捉ESR研究   总被引:2,自引:4,他引:2  
在光引发剂二苯甲酮(BP)存在下,紫外光辐照低密度聚乙烯(LDPE)所形成的自由基中间体已被自旋捕捉剂2,4,6-三特丁基亚硝基苯(BNB)所捕捉,其自旋加合物自由基已为电子自旋共振(ESR)所特征。现已检测和鉴定到二种自旋加合物:一种是叔碳自由基;另一种是仲碳自由基。它们分别是由BP的激发三重态从LDPE链的支化点和亚甲基团上夺氢所形成的自由基中间体同自旋捕捉剂BNB反应生成的。上述的证据表明:LDPE的光引发交联点主要发生在叔碳和仲碳原子上,且H-型交联点占主导地位。  相似文献   

17.
B S Prabhananda 《Pramana》1990,34(6):491-506
The “minimum linewidths” seen in the ESR linewidths against temperature plots, the dependence of line widths on the63Cu nuclear magnetic quantum numbers and the Hubbard relation provide sufficient number of equations to determine the anisotropic ESR parameters in the case of axially symmetric Cu(II) complexes even when unresolved hyperfine structures make contributions to linewidths. After testing the method by reanalysing the literature data on Cu(II) bis-acetylacetonate, it has been used to obtain the anisotropic ESR parameters in the case of bis-salicylaldehydate of Cu(II). Linewidth contributions from unresolved hyperfine structures associated with the1H of coordinating CHCl3 inferred in these studies, were confirmed by comparing the widths in CHCl3 and CDCl3 under ideal conditions. The temperature dependence of this contribution and the estimate of rate constant at room temperature (∼ 1010 s−1) suggest that the coordinating solvent exchange is diffusion controlled.  相似文献   

18.
陈炳焕  万谦 《波谱学杂志》1989,6(3):382-385
本文介绍了TE_(011)模式园柱形ESR样品腔的设计方法和作者的一个设计实例.  相似文献   

19.
Electron spin resonance spectra of manganese-doped calcium hydroxide were studied at room temperature for Mn concentrations between 0.01 and 2.00 mol%. The results suggest that the range of the exchange interaction between Mn2+ ions is about 1.05 nm.  相似文献   

20.
本文研究了不同处理条件(处理功率、处理时间和处理压力)下等离子体气体(Ar、N2、O2和空气等)对高密度聚乙烯表面处理产生的自由基的ESR谱。我们观察到等离子体处理产生的自由基是相当稳定的,它的ESR信号强度随处理功率和处理时间增加而增加。但处理压力对它影响不大。我们证明了紫外线对高密度聚乙烯表面产生自由基作用随处理条件而变化。并初步解释了谱的超精细相互作用。  相似文献   

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