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1.
研制了紫外、可见、近红外光谱区通用光谱透射比较标准物质。以高纯熔融石英为基片材料,镍铬合金的镀膜材料,采用双光楔对称光胶结构以消除同色杂散光的影响,对镀膜进行光胶处理以保证膜层的强度、稳定性及光学中性,采用高精度分光光度测量装置作为定值手段的以保证准确的定值,设计定位保护架以消除多次反射误差。该光度标准适用的光谱范围的200-2600nm,光谱透射比定值不确定度为0.5%。  相似文献   

2.
现场光谱电化学研究的新进展   总被引:3,自引:1,他引:3  
电化学以两个凝聚相的荷电界面为其主要研究对象.它广泛地应用于能源、材料等重要科学领域,并对生命科学的发展发挥着重要作用[1,2].为了从分子水平上深化对电化学界面的认识,自七十年代中至八十年代初采用了紫外可见反射、拉曼和红外光谱技术对电化学体系进行现场(in-situ,又称原位)研究,开创了光谱电化学新领域[3,4].光谱电化学在/\十年代发展迅速,推动电化学研究由宏观进入微观、由统计平均深入至分子水平【‘一刀.近年来,随着各种光谱仪器性能的提高以及非线性光谱等新技术的发展,现场光谱电化学研究不断拓宽新领域,…  相似文献   

3.
孙涛  蒋晓春 《分析化学》1994,22(7):679-682
为了更方便有效地进行凝聚相有机磷酸酯的红外光谱规律及谱图解析的研究,利用计算机的软,硬技术设计出一套用于微机的光谱辅助分析软件包,功能齐全,操作灵活,可完成多种化合物分类模式检索;可进行多谱图叠加,吸收峰直方图的显示,峰的自动识别及范围确定;可进行差谱分析,谱图显示操作灵活,可进行绘图仪输出,在实际分析应用中有效好的效果。  相似文献   

4.
报道了配合物Eu(XnP)3·3H2O[其中X=H,2-Cl,3-OH,4-Br,3-NO2,2-OCH3,2-CH3,2,4-二氯;P=2-(COO)C6H4CONHC6H5-n-,n=1,2]的制备,并用元素分析,红外光谱,电子反射光谱,热重分析进行了表征。结果表明配位是通过羧酸基上氧原子和酰胺羰基氧原子进行的,含3分子水。通过电子反射光谱,对Nephelauxetic比率(B),平均共价参数(δ)和平均成键参数(b1/2)进行了计算,对配合物的共价成键情况进行了讨论。  相似文献   

5.
李景虹  程广金 《分析化学》1994,22(8):841-848
本文对激光光谱电化学的基本问题及研究现状进行了评述,简述了其历史的发展过程,按实验方法将其进行分类并阐述了相应的特点和装置,较系统地介绍了其在理论方面研究和电化学中应用,展望了发展方向,共引用41篇文献。  相似文献   

6.
脲盐的电子结构及其与光谱和能谱的关系   总被引:1,自引:0,他引:1  
对脲盐的振动和电子光谱及X光电子能谱进行研究,并用电荷自洽场DV-Xα方法计算其电子结构,确定脲盐正离子CO(NH2)2H^+的结构特征,分析其结构变化与光谱和能谱现象的内在联系,并由此提出了形成配合物的反应机理。  相似文献   

7.
运用正交投影技术,结合目视背景光谱平滑性,对二元共混物中各组分进行红外光谱定量分析。将该法用于聚乙烯/聚丙烯共混物的实际样品测定,能满足生产控制的要求。  相似文献   

8.
首次从猪肝中提取、分离和纯化了二氢蝶啶还原酶(DHPR),并对猪肝二氢蝶啶还原酶冻干固体水溶液和重水溶液进行了激光拉曼光谱研究,测量了它们的拉曼光谱,对其主要拉曼特征频率进行初步指认,按照Lippert方法计算了它的α螺旋、β折叠和无序结构的相对百分含量。  相似文献   

9.
记录了(E)-2-二甲基-1,3-戊二烯的固,液,气态FTIR光谱(400~4000cm^-1)和固、液态Raman光谱(50~4000cm^-1),观测了685及658cm^-1谱线的变温FTIR光谱(-73~10℃),对所得谱图进行了指认分析发现,该化合物存在两种单键旋构象异构体s-trans和s-cis,由变温FTIR光谱峰强度随温度的变化得到了这两种构象互变的△H^0和△S^0。  相似文献   

10.
用AM1和INDO/S-CI方法对2-(2'-羟基苯基)苯并咪唑的基态和激发态分子内质子转移反应进行了理论研究,求得基态和激发态反应的势能曲线、势垒和过渡态,并研究了此分子的一些异构体、阴离了的相对稳定性,估算了氢键能。进行了实验光谱的理论指认,所得结果与实验值符合较好。在此基础上对光化学反应机理和光谱性质进行了探讨。  相似文献   

11.
The microcalorimetric technique is employed to study the interaction of NO and NO 2 with the In/HZSM 5 catalyst which has been reported to be active for the selective catalytic reduction (SCR) of NO by CH 4. The amounts of chemisorption and differential heat of NO 2 adsorption on In 2O 3, HZSM 5 and In/HZSM 5 are much larger than those of NO. Furthermore, NO 2 adsorption on In 2O 3 is irreversible. Associating with the results of in situ IR and TPD, and the NO x conversion in NO(NO 2)+CH 4 system over In/HZSM 5 and HZSM 5 catalysts, it is reasonable to propose that in the CH 4 SCR process NO 2 plays a key role, and NO 2 species chemisorbed on the HZSM 5 support can migrate to the In sites to react with CH 4.  相似文献   

12.
采用分子动力学模拟方法研究过氧化氢水(HP)溶液作用下结构I型(SI)甲烷水合物晶体分解特性. 系统分析甲烷水合物在过氧化氢水溶液作用下由晶态向液态转变过程的机理, 对比相同摩尔浓度乙二醇(EG)溶液作用下甲烷水合物分解变化规律, 得出HP与水合物热力学抑制剂EG一样对甲烷水合物分解具有促进作用, 为HP溶液促进甲烷水合物分解实验研究提供参考.  相似文献   

13.
In the solid rocket propellant formulations an important component is the polymeric binder. Actually, the most used binder is hydroxyl-terminated polybutadiene. However, the research is oriented toward the use of energetic polymers which, in addition to the binder function, should improve the propulsion capability of the propellant. In this respect, good candidates are oxetanic polyethers with azidic functionalities in their side chains. Considering the explosive character of such materials, their synthesis must be designed with attention to the safety of the process. In this note, the preparation of azidic copolymers is described and different synthetic strategies are discussed and compared.  相似文献   

14.
Nikolić  Kosta  Medenica  Mirjana 《Mikrochimica acta》1986,88(5-6):325-329
Two methods are described for the potentiometric determination of 8-chlorotheophylline in aqueous solution. Both methods are based on the reaction of 8-chlorotheophylline with silver ions. In the first, the nitric acid produced in the reaction is titrated with sodium hydroxide. In the second, the 8-chlorotheophylline is titrated directly with silver nitrate in sodium carbonate medium. Both methods give reasonably accurate and reproducible results, and are suitable for the assay of 8-chlorotheophylline in pharmaceutical preparations.  相似文献   

15.
High molecular weight polytetrafluoroethylene (PTFE) is transformed to free-flowing micropowder by treatment with electron beams. In case of irradiation in presence of air carboxylic acid fluoride groups are incorporated which rapidly hydrolyze to carboxylic groups in the surface-near regions due to atmospheric humidity. These polar groups reduce the hydrophobic and oleophobic properties so much that homogeneous compounding with other materials becomes possible. In addition to PTFE, copolymers of tetrafluoroethylene with hexafluoropropylene (FEP) and perfluoropropylvinylether (PFA) were modified. In case of identical irradiation conditions, the concentration of carboxylic groups is much higher in FEP and PFA than in PTFE, which is due to the lower crystallinity of the copolymers.

Electron beam irradiation of PTFE was performed in vacuum at elevated temperature above the melting point. The changes in the chemical structure were studied. The concentration of CF3 branches was found to be much higher as compared to room temperature irradiation.

In a practical test PTFE micropowders functionalized by electron irradiation were compounded with epoxy resins, with polyoximethylene and with polyamides. Such compounds are characterized by very good frictional and wearing behaviour in dry-running tests.  相似文献   


16.
本文对三种体系的漆酶热失活动力学进行了研究,并对动力学参数进行了相应的分析。结果显示,漆酶在纯水溶液中的失活符合一级动力学模型,其失活方程为lnA=-0. 1353t-2. 2522。在有毒有机物体系(2,4-二氯酚和吲哚溶液)中漆酶的失活仍符合一级失活动力学模型,失活速率常数减小,但半衰期增大。在极性溶液(乙醇)中,漆酶的反应速率常数最小,可能是因为漆酶分子内部作用力的变化导致了漆酶反应变缓;在非极性体系(异辛烷溶液)中,水-疏水体系减少了对酶的伤害,利于酶的稳定,延长了漆酶半衰期;极性或非极性体系中的漆酶失活均符合一级动力学失活模型。  相似文献   

17.
Pribil R  Veselý V  Horácek J 《Talanta》1967,14(2):266-267
A new method for the determination of thorium and scandium in the presence of each other is presented. Two aliquots of the solution are necessary. In one the sum of thorium and scandium is determined by direct titration with DCTA. In the second, thorium and scandium are treated with an excess of TTHA, phosphate is added, and zinc is used to titrate the excess of TTHA and to displace the scandium from its TTHA complex.  相似文献   

18.
土壤腐殖质各组分红外光谱研究   总被引:14,自引:0,他引:14  
肖彦春  窦森 《分析化学》2007,35(11):1596-1600
土壤腐殖质是土壤中所特有的一类特殊的高分子化合物,具有重要的肥力和环境调节功能。其中胡敏素的提取和纯化很困难,从而限制了对其性质和结构的研究。为揭示胡敏素的结构性质,本研究按Pallo分组,将胡敏酸(HA)分为焦磷酸钠提取的胡敏酸(HAP)、氢氧化钠提取的胡敏酸(HAS);富里酸(FA)分为焦磷酸钠提取的富里酸(FAP)和氢氧化钠提取的富里酸(FAS);胡敏素(HM)分为铁结合胡敏素(HMi)、粘粒结合胡敏素(HMc)和不溶性胡敏素(HMr)三个组分,采用红外光谱法对黑土、草甸土以及黑土底土加入大量玉米秸秆培养后腐殖质各组分的结构特征进行研究。腐殖质各组分按Pallo法分组。结果表明:铁结合胡敏素(HMi)、粘粒结合胡敏素(HMc)与胡敏酸(HA)、富里酸(FA)具有相似的光谱特征,但存在明显差异。黑土、草甸土中HMi和HMc的脂族性强于HA和FA;HMi与HMc相比,HMi具有较高的脂族性。黑土中氢氧化钠提取的胡敏酸(HAS)的脂族性强于焦磷酸钠提取的胡敏酸(HAP);NaOH提取的富里酸(FAS)的脂族性强于Na4P2O7提取的富里酸(FAP)。草甸土中HAP的脂族结构较多,而HAS脂族结构相对较少。在培养土中,新形成的FA脂族性强于HA、HMi和HMc组分。新形成的HMc脂族性强于HMi和HMc的脂族性强于HAP,而弱于HAS。  相似文献   

19.
In the presented model elements of polymer melt rheology and polymer crystallization kinetics are combined. In particular, the proneness of the melt to the special type of crystallization which is characteristic for shear treatment is supposed to emerge only gradually during shear flow. Following Avrami's early ideas on crystal growth, an induction time is introduced. In principle, the model can be applied to any flow and temperature history. The special case of isothermal flow at constant shear rate is covered in greater detail: A favorable comparison is made with experimental results, as published by Lagasse and Maxwell [10].Dedicated to Prof. J. Meissner on the occasion for his 60th birthday.  相似文献   

20.
The determination of lanthanum by measuring its flame emission at several wave lengths has been evaluated by means of two recording spectrophotometers equipped with special photomultiplier detecting devices. In addition, a comparison of the effect of an aqueous and alcoholic medium was carried out. In general, the interference from foreign ions is least at the higher wave length of 743 mμ. In most cases, especially with transition elements, the interference is lessened when 1 : 1 water-methanol solution is used. The exceptions to this rule are titanium,thorium and zirconium which cause less interference in an aqueous solution. The method used in conjunction with a standard addition technique, has been applied to the determination of lanthanum in solutions of thorium oxide, uranium, glass, and didymium oxide mixtures.  相似文献   

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