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利用UV光谱方法研究了7种具有不同立体结构的铁(Ⅲ)卟啉络合物在PhIO存在下的氧化分解反应.动力学初步研究表明铁(Ⅲ)卟啉络合物的氧化分解对铁(Ⅲ)卟啉络合物是二级反应.7种铁(Ⅲ)卟啉络合物的氧化分解速率常数(mol-1·L·min-1)大小顺序为(To-RPPFeCl,R=):H》Me(71.1)>Et(59.1)>n-Pr(42.2)>t—Bu(-27.3)>n-Bu(21.0)<i-Pr(9.86).加入某些中性有机配体能减小铁(Ⅲ)卟啉络合物的氧化分解速率.根据研究的结果提出了铁(Ⅲ)卟啉络合物氧化分解反应的可能机理为: 相似文献
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在一定的温度下,CU-Al2O3界面处由于氧元素的引入,铜的表面形成一层cu-Cu2O共晶熔体,这一熔体能同时湿润铜和陶瓷,降温后使Cu-Al2O3形成牢固键合.到目前为止,其健合机理还不十分明了.本文运用扫描电镜(SEM)、能谱分析(EDX)、X射线衍射(XRD)技术对Cu-Al2O3界面的键合结构及生成的物相进行了系统的研究. 相似文献
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为建立具有局部可数基的空间和度量空间之间的关系,证明了:(1)空间X是具有局部可数的空间当且仅当X是某一局部可分度量空间的紧复盖、开、SS-映象,当且仅当X是某一度量空间的开、ss-映象;(2)空间X是具有局部可数基的kR-空间当且仅当X是某一局部可分度量空间的紧复盖、R-商、开、ss-映象当且仅当X是某一度量空间的R-商、开、ss-映象;(3)空间X是具有可数基kR-空间当且仅当X是某二可分度量空间的R-商、开映象. 相似文献
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前言自1948年Searle发表了N-取代马来酰胺(RMI)的合成后,约在10年后的1958年才开始研究马来酰亚腔和RMI的聚合和共聚。自那以来虽对MRI进行了大量的研究,但只是近年来才相继发表了其高收率合成法及其聚合物的专利。以工业规模合成并销售的只有N-环已基马来酰亚(CHMI)和N-苯基马来酰亚胺(PMI)。这些马来酰亚胺通过共混或共聚来提高热塑性树脂的耐热性。目前RMI聚合物本身尚未成为塑料和功能材料。现在每年有250件关于RMI的专利报导,但本文仅就其聚合性、共聚性及制成的聚合物和共聚物的性能以及最近的研究动向作一介绍。… 相似文献
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试验合成了两种新型的N-苯基取代苯并咪唑二胺,区别在于N-苯基的邻位分别由甲基和氟原子取代.将新型二胺分别与二酐4,4′-(六氟异丙烯)二酞酸酐(6FDA)和4,4′-氧双邻苯二甲酸酐(ODPA)通过两步热亚胺法制备聚苯并咪唑酰亚胺(PBII)薄膜,并对新型二胺单体及PBII薄膜进行了性能测试与表征.结果表明:新型PBII薄膜表现出良好的耐热性(玻璃化转变温度Tg=341~381℃)和拉伸强度(σ=95~135 MPa).不同邻位取代的N-苯基破坏了分子的有效堆积,使得PBII薄膜的溶解性和光学透明性得到改善. 相似文献
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用一元线性回归分析法处理实验数据.研究了铝—铬天青S—氯化十六烷基吡啶(Al(Ⅲ)—CAS—CPC),亮绿色体系的反应特性及适宣条件.体系的最大吸收波长为632.5nm.表观摩尔吸光系数ε=7.76×104Lmol-1cm-1.其组成摩尔比为AlCAS=13.服从比耳定律范围0~9μg/50ml.检测限为3.45ng/ml.应用于茶叶、饮料、饮水中微量铝的测定,结果满意. 相似文献
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Mn-Fe/TiO2低温NH3选择性还原NO催化活性及其反应机制 总被引:3,自引:2,他引:3
采用共沉淀沉积法制备了Mn-Fe/TiO2 NH3选择性催化还原(SCR)NO催化剂,80℃时即获得了92.5%的NOx转达化率,在j( H2O) = 6% 和 j( SO2) =0.01%条件下120℃时转达化率保持在95%以上。X衍射光谱(XRD)结果表明,Fe2O3与与MnO2存在相互作用,两者均匀地分散在载体TiO2表面。傅立叶转换红外(FT-IR)及原位红外(Situ IR)光谱分析得出反应机理为:Fe2O3为助催化剂,NH3主要以-NH2形式吸附在MnO2的Lewis酸中心上,与NO生成中间产物NH2NO,再分解成最终产物N2和H2O;少量以NH4+形式吸附在Br?nst酸中心上。O2能同时增加Lewis酸中心和Br?nst酸中心形成中间产物的途径。 相似文献
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基于主成分回归分析的SF6分解组分红外光谱定量 总被引:1,自引:0,他引:1
SF6气体分解组分的定量分析对于气体绝缘组合电器(gas insulated switchgear,GIS)设备的在线监测与故障诊断具有重要的意义。基于朗伯比尔定律进行气体红外定量分析时存在吸收系数的难确定性和多组分检测的繁琐性问题,为解决此问题,采用了主成分回归分析的红外定量算法,并选取SO2F2、SOF2、SO23种分解组分及其特征吸收峰作为研究对象。该算法分别以光谱数据与气体体积分数作为输入和输出,建立了吸收光谱图与浓度信息的直接对应关系。试验配制了3种特征组分的含量样本,由训练样本获得光谱数据并依据算法建立了红外定量预测模型。通过比较主成分回归分析算法和拟合法的红外定量效果,表明了回归算法模型定量精度高于拟合法。检验样本和实测数据的预测结果都表明,该算法和预测模型具有很好的适用价值。 相似文献
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An attempt was made to study the structural behavior of a crystal in bone composite material of rats and rabbits. A Fourier transform infrared (FTIR) spectrophotometer and computer were used to monitor the infrared spectra of five bone samples each from the rats and rabbits. The spectra indicate the absorption band in the region of 500 to 700 cm -1, with a wider bandwidth in the samples of rats as compared to rabbits. The spectra indicate that (1) the amorphous crystalline behavior of bone crystal is animal specific: (2) bone surface resorption is greater in amorphous bone; (3) cortical thickness may be affected by the bone's molecular structure; and (4) the mineral deposits on the collagen matrix are mediated through a biophysical mechanism that follows a crystallographical arrangement in the protein lattice 相似文献
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Sundararajan R. Mohammed A. Chaipanit N. Karcher T. Liu Z. 《Dielectrics and Electrical Insulation, IEEE Transactions on》2004,11(2):348-361
Aging and degradation of 345 kV ethylene propylene diene monomer (EPDM) transmission line insulators removed from service is presented. These suspension type insulators were installed in a New Hampshire coastal area in 1995 and were removed in 2000 after unexplained outages in that structure. The purpose of this paper is to better understand the aging and degradation mechanisms of EPDM insulators in service. The insulators showed severe chalking and discoloration and partial loss of hydrophobicity on the side facing the sun. The surface structural changes were studied in detail using advanced surface analysis techniques, such as attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). For the first time, the significant differences in surface properties between the chalked/discolored (white) and the other surfaces (dark) were studied quantitatively. The Fourier transform infrared (FTIR) absorption spectra showed a significant decomposition of the CH groups of the white surface, elucidating the effect of photo-oxidation on the EPDM polymer. The SEM micrographs showed the cracking of the surfaces. The XPS spectra showed the formation of various polar carboxyl groups and the presence of high surface energy compounds, such as silica, and silicates. This study provided valuable basic information on the changes in the surface properties of EPDM insulators during service in a coastal environment. 相似文献
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Electronic structures were investigated on Pb(Zr1 ?xTix)O3 (PZT) using the discrete variational Xα cluster method for obtaining the information of dependence on the amount and position of the substituted Zr atoms. Also, we investigated the effect of them on fatigue. The net charge and the overlap population were discussed together with the energy gap, which is related to fatigue. As a result, the net charge was independent on the amount and position of the substituted Zr atoms, and the overlap population wasn't. Furthermore, from the calculated energy gap, we conclude that Zr-rich PZT is less susceptible to fatigue than Ti-rich PZT. 相似文献
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Dr.-Ing. D. Brandes 《Electrical Engineering (Archiv fur Elektrotechnik)》1967,51(3):155-175
Übersicht Der Eisenkern einer Wicklungsanordnung beeinflußt das magnetische Feld und als Folge davon auch die eingeprägten Kräfte, die Wirbelstromverluste usw. oft maßgebend. Dieser Eisencinfluß wird in der vorliegenden Arbeit als rotationssymmetrisches Problem behandelt. Es wird dabei erkannt, daß sich der Kern in bezug auf seine Brechungseigenschaften durch einen Strombelag auf der Oberfläche ersetzen läßt. Der Einfluß des unendlich langen, kreiszylindrischen Eisenkernes ist damit identisch mit den Induktionen des Strombelagfeldes. Für die Lösungen ist nur der Verlauf der Tangentialfeldstärke der Luftanordnung auf der Grenzschicht erforderlich. Durch die angegebene Näherung der exakten Lösung läßt sich der Rechenaufwand wesentlich vermindern. Im Zusammenhan mit dieser Lösung wird das Problem des Mehrwicklungstransformators behandelt.
Contents The iron core of an arrangement of windings influences often determining the magnetic field and in consequence of that the impressed forces, the eddy-current losses and so on. This effect on the iron core is dealt with in the present paper as an axially symmetrical problem. It is recognized there, that the core can be substituted by a current coverage on its surface with regard to its index of refraction. The influence of the infinite tall circular cylindrical iron core is identical with the magnetic flux of the current coverage field. For these solutions it is only necessary to know the course of the tangential field intensity of the arrangement without iron on the interface. By the stated approximation of the exact solution the expenditure of the calculation can be essentially reduced. In connection with this solution the problem of the transformer with a random number of windings is dealt with.相似文献
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循环水中有机物浓度高易引起微生物滋长和膜污堵,提高循环水利用率必须对其加以处理。采用传统化学分析,结合紫外-可见光谱、凝胶色谱和三维荧光等手段,研究了强化混凝对循环水中有机物的去除特性。结果表明:(1)在0~120mg/L内,随FeCl3投加量增加,混凝对有机物去除率增加;溶解性有机物分子缩合度降低,分子量减小。(2)在FeCl3质量浓度为120mg/L条件下,混凝对总有机碳(TOC)和溶解性化学需氧量(SCOD)去除率分别为54.06%和33.33%;腐殖质类物质C1、C2和蛋白质类物质C3的荧光强度Fmax值分别下降了48.02%、66.38%和22.27%。说明强化混凝可有效降低循环水中有机物浓度,特别是去除难被生物降解的腐殖质类物质效果明显,因而可通过旁流强化混凝处理循环水,提高循环水系统运行稳定性,为循环水进一步进行膜处理奠定良好基础。 相似文献