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1.
研究了以对二氯苯和硫化钠为原料来制备聚苯硫醚;考察了制备过程中的各种影响因素,特别是添加水量对产率的影响;探讨了有关作用机理;测定了产物的某些物理性能;用红外光谱、差热分析、X射线衍射等手段对聚合物进行了表征。结果表明:聚合物C—S键的伸缩振动位于1091 cm~(-1),482 cm~(-1)中等强度峰系S—S键的特征吸收;聚合物为结晶性物质;热分解有两个区域,分别是282.5℃的吸热峰与582℃处的放热峰。  相似文献   

2.
建立快速监测提取过程的实验方法.使用傅里叶变换红外光谱(FT-IR)结合导数光谱(SD-IR)的方法对炙甘草不同溶剂逐级提取的过程进行化学成分进行分析.结果表明,醇提物FT-IT图谱中,1 512 cm~(-1)峰较强,说明其中含黄酮类成分量较高,醚提取物中可见,有2 925、2 854 cm~(-1)为C-H伸缩振动,1 738 cm~(-1)等峰位羟基C=O伸缩振动吸收峰,说明可能主要为三萜类成分,另外在1 300 cm~(-1)以下,亦有明显的C-O伸缩振动吸收峰,即糖类的特征峰.在酯提取物中,亦出现2925、2853、1 707 cm~(-1)等峰位羰基C=O伸缩振动峰,1 614 cm~(-1)峰特别明显,1 508、1 455 cm~(-1)等峰也相对较明显,说明可能有黄酮类成分被提取出来.SD-IR能够进一步印证FT-IR的实验结果.利用FT-IR结合SD-IR的高强指纹性能够快速、准确地监测提取过程,实现中药提取过程的实时监控.  相似文献   

3.
丙酮处理酵母菌吸附铅前后红外光谱分析比较   总被引:5,自引:0,他引:5  
对丙酮处理酵母菌吸附铅前后的红外光谱进行了分析比较。生物材料的红外光谱图主要由蛋白质的吸收带、碳水化合物的吸收带组成。1652cm^-1、1534cm^-1、1239cm^-1处的吸收峰是蛋白质的三个特征吸收峰。1455cm^-1处的吸收峰为CH3和CH2的弯曲振动峰;1397cm^-1处中等强度的吸收归属于羧基的对称伸缩振动。1200-940cm^-1之间出现的强且复杂的谱带归属于醚和碳水化合物中的C-O伸缩振动。915cm^-1、890cm^-1处两个弱的吸收峰属于细胞壁中多糖的糖环键的振动。吸附pb^2 后,3375cm^-1处的吸收峰紫移至3388cm^-1,1398cm^-1处的峰红移到1384cm^-1,说明羟基和羧基在结合pb^2 起重要作用丙酮处理酵母菌的主要成份和结构吸附前后保持完整。  相似文献   

4.
本文提供了峰峰黄沙肥煤的红外光谱图。发现在1025cm~(-1)处有一强峰,经氢碘酸处理煤样后,光谱图中的1025cm~(-1)峰消失,2eisel试验得正性结果,因此认为,1025cm~(-1)峰是由c-o-c伸缩振动引起的,所以,峰峰黄沙肥煤中含有醚的官能团。  相似文献   

5.
【目的】了解在升温过程中β-胡萝卜素分子内不同基团之间的相互影响。【方法】采用二维相关红外光谱分析技术,研究β-胡萝卜素在30~100℃变温微扰过程中的动态光谱变化。【结果】β-胡萝卜素分子的吸收特征峰在一维红外光谱和二阶导数谱上变化不明显,表明其没有发生氧化反应。二维相关分析表明,反式共轭烯烃C—H面外弯曲振动的968cm~(-1),烯烃C—H基团反对称弯曲振动的1 442cm~(-1),甲基C—H反对称伸缩振动的2 966cm~(-1)和烯烃C—H的对称伸缩振动的3 012cm~(-1),这些吸收峰的光谱变化对温度比较敏感。同时在微扰过程中,不同基团变化的先后顺序:亚甲基热运动引起的光谱变化快于甲基的,低波数的甲基碳氢对称伸缩振动的光谱变化快于高波数的甲基反对称伸缩振动,烯烃碳氢对称伸缩振动热运动引起的光谱变化快于烯烃碳氢反对称伸缩振动。【结论】在微扰作用下利用二维相关分析可以提高谱图的分辨率,这为β-胡萝卜素在升温过程中构象变化的机理提供实验基础。  相似文献   

6.
本文叙述了傅里叶变换红外光声光谱法(FTIR-PAS)的基本原理及其在纺织上应用。研究了组合浆料中变性聚乙烯醇的定量测定、涤棉混纺纤维中涤纶的定量测定、苎麻及甲壳素经碱处理后的光谱性质的变化。研究结果表明,以变性聚乙烯醇C=O基团的伸缩振动1570cm~(-1)吸收峰可作为定量测定变性聚乙烯醇的依据。以涤纶分子结构中羰基伸缩振动1725cm~(-1)峰高与纤维分子结构中碳氢键伸缩振动2915cm~(-1)峰高的比值,可定量测定涤棉混纺纤维中涤纶含量。苎麻经碱处理后,非晶谱带898cm~(-1)度明显增加,晶区谱带1430cm~(-1)强度明显下降,其变化程度取决于碱浓度。甲壳素的酰胺吸收峰1555cm~(-1)随碱处理浓度、温度和时间的增加而下降。与常规的红外吸收光谱法相比较,傅里叶变换红外光声光谱法具有无损快速的优点,适宜于制作困难的试样。  相似文献   

7.
小麦壳的差热分析与红外光谱分析   总被引:4,自引:0,他引:4  
对麦壳的热重曲线、差热曲线进行了分析,并对麦壳的红外光谱分析.加热250℃时质量损失约7%,250 ̄310℃时质量损失约50%,到460℃质量仅余约12%.在325℃、430℃分别有两个放热峰.麦壳的红外吸收光谱图主要由碳水化合物如木质素、纤维素等吸收带组成.1735cm-1和1615cm-1处的吸收峰是由C=O的伸缩振动引起的;1515cm-1的吸收峰是苯环的骨架振动峰,1243cm-1处是苯羟基中C-O的伸缩振动峰.  相似文献   

8.
微孔交联淀粉的制备及其对Zn(Ⅱ)的吸附FIRT和XRD分析   总被引:1,自引:0,他引:1  
以可溶性淀粉做原料,用N,N′—亚甲基双丙烯酰胺交联,过硫酸铵引发聚合得到微孔交联淀粉(MCS),并研究了其对Zn~(2+)的静态吸附行为;用红外光谱仪和X射线衍射仪对MCS及其吸附产物进行了对照分析。结果表明:MCS对Zn~(2+)的吸附符合Freundlich等温方程,吸附量达到2.36 mmol/g;MCS在1536 cm~(-1)处出现酰胺Ⅱ带N-H弯曲振动吸收峰,表明了淀粉与MBAA成功交联;MCS在3445cm~(-1)附近的N—H、O—H伸缩振动偶合而增宽的多重峰在吸附产物中变宽,且向低波数位移,而1536cm~(-1)处的酰胺Ⅱ带N—H弯曲振动吸收峰则移至1543cm~(-1)处,说明在吸附过程中,MCS的酰胺基团上的N、O原子可能与Zn~(2+)发生了配位反应;XRD显示,可溶性淀粉经交联后结晶度降低至6.4%左右,MCS上的酰胺基和—OH与Zn~(2+)形成配位键使MCS的晶形结构被进一步破坏,结晶度约为0.5%左右,已基本处于无序的非晶态。  相似文献   

9.
分别利用0.1mol/L的NH_4Cl和HCl对BETA沸石分子筛进行了离子交换.结果表明,HCl导致了BETA沸石骨架脱铝,而NH_4Cl则对骨架铝无影响.红外光谱的OH振动频率显示出了两个谱峰在3740cm~(-1)和3610cm~(-1)处,分别归属于Si—OH和Si(OH)Al基团.吸附吡啶的红外光谱表明,不仅3610cm~(-1)而且部分的3740cm~(-1)谱带也显示了较强的酸性.  相似文献   

10.
本文研究了 Y、La、Ce、Pr、Nd、Sm、Eu、Gd、Dy、Ho 十种丙酮酸稀土化合物的 FT-IR 光谱,对400-2000cm~(-1)的主要红外吸收谱峰进行了归属.400-200cm~(-1)有三个随稀土原子序数递增峰位向高频率位移的谱带,指认为M-O 伸缩振动吸收峰。它们的红外光谱表明,丙酮酸以酸根形式采用螯合桥式三齿方式配位,并且某些谱峰有裂分或拓宽现象。配位键以离子键成分为主。  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.
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   

13.
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   

14.
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   

15.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

16.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

17.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

18.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

19.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

20.
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