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1.
本文对X·C_2H_2[X=(CH_3)_3N、NH_3、(CH_3)_2O和CH_3(N)及(NH_3)_2·C_2H_2]五种分子间氢键络合物体系进行了振动光谱研究。用MNDO方法对这五种体系进行了几何构型优化,获得了直角坐标力常数;通过力常数变换将其转换成内坐标表达的力常数,用GF矩阵方法作全振动分析,计算了上述体系的振动光谱频率,并对频率作了理论归属,从而得到了分子间氢键的伸缩振动力常数和振动频率。  相似文献   

2.
The molecular motion in polyepichlorohydrin (PEPCH), in solution and bulk, was studied by high resolution NMR by means of line width, spin-lattice relaxation time T_1 and nuclear Overhauser effect NOE. The results show that the VJGM model can describe the main chain motion of PEPCH in solution perfectly. In bulk state, the relationship between the line width and the temperature is consistent with WLF equation, but that between the high frequency molecular motion correlation time (in T_1 scale ) and temperature is consistent with Arrhenius equation. The motion parameters of PEPCH in both states were calculated. The internal rotation motion of side—CH_2Cl group was analyzed by using equal three-site jump and diffusion internal rotation model in both states.  相似文献   

3.
对生物探针与脱氧核糖核酸(DNA)的结合模式及有机染料分光光度法测定DNA的研究进展进行了综述。引用文献71篇。  相似文献   

4.
Numerical integration is performed of the KDV equation of the forced dissipation with the result that it takes about 10 days to transform a high-index circulation into a blocking pattern, in whose establishment and maintenance the thermal forcing and dissipation, nonlinoear advection, and linear dispersion are equally important and serve as three factors of essentiality.  相似文献   

5.
By comparing the different developmental characteristics of two types of sperm nucleiwhich were from gynogenetic fish (crucian carp) and amphimictic fishes (red carp, redgoldfish and sex--reversal red carp) respectively in the eggs of gynogenetic crucian carp, itwas preliminarily revealed that there existed selective inhibiting actions of the primarycontrol in the eggs of crucian carp for inhibiting the development of the two types of spermnuclei. To homologous sperms, the primary control showed weak effect, thus leading tothe decondensation of homologous sperm nuclei at different degrees in the eggs of cruciancarp. But to heterologous sperms, the primary control showed strong effects, resulting in thetotal inhibition of the development of heterologous sperm nuclei. Moreover, our experimentalresults also showed that the different developmental behavior of the two types of spermnuclei might have a great relationship to the changes or the sex ratio in the population ofgynogenetic crucian carp. The infiltr  相似文献   

6.
Using ~(13)C CP MAS TOSS DD NMR, some rules governing the variations of structureparameter and fractional contents for various aliphatic carbon in the mudstone kerogensburied in different depths in China are first reported in this paper, and the preliminarystudies on their natural evolution as well for the formation of oil and gas have been made.The influence of T_(CP), T_(CH), f_(rsc) on quantity measurement of CP in kerogens is discussed.  相似文献   

7.
利用荧光光谱法研究了绿原酸与人血清白蛋白(HSA)的相互作用,考察了不同温度下绿原酸与HSA的结合常数KA和结合位点数n,并研究了Cu2+、Al3+、Ca2+、Pb2+等金属离子对绿原酸与HSA结合性质的影响。基于Frster偶极-偶极非辐射能量转移机理确定了荧光给体HSA与受体绿原酸间的结合距离。  相似文献   

8.
对GB/T 13906- 1992《空气质量氮氧化物的测定》中的中和滴定法与《空气和废水监测方法》(第4版)、《污染源统一监测方法》(废气部分)中的分光光度法进行比较并进行改进,通过试验,研究了高浓度氮氧化物含量的测定方法,为企业解决硝烟污染问题提供理论依据.  相似文献   

9.
The ~(13)C T_(1s) of --CH_3 side group in PPU/P (St-co-AA), AB-crosslinked polymers (i. e.ABCP) was studied by using high resolution solid state NMR. The rotation motion of --CH_3 sidegroup in PPU was analyzed by means of the average spectral density functions of internal rota-tion. The results showed that the rotation of the --CH_3 side group is related closely to the com-patibility between the two components. The compatibility was studied by analyzing the protonspin-lattice relaxation in rotating frame, spin-spin relaxation and spin-diffusion. The resultsshowed that the hydrogen bonds between the components play a major role in determining thecompatibility. Through spin diffusion studying, the soft phase domain size was calculated. Bystudying proton spin-spin relaxation, the content of each component in each phase and that ofeach phase in the samples can be obtained. The result shows that the content of interphase is related closely to the compatibility.  相似文献   

10.
Poly(p-phenylene) (PPP) films have been electrochemically deposited on mirrorlike stainless steel (SS) electrode surfaces by direct oxidation of benzene in boron trifluoride diethyl etherate (BFEE) solutions at a constant applied potential of 1.7 V (versus Ag/AgCl). The chain conformations of as-grown PPP films have been studied by Raman spectroscopy. The results demonstrated that high synthesis temperature favors the formation of planar PPP, and the conformation of planar PPP can be changed into torsional PPP by cooling treatment.  相似文献   

11.
A 1-dimensional K-model parameterized by the local similarity theory is used to study the structure of the stably stratified boundary layer. The computed results are quite consistent with those of the second-order moments model. Thus, the model can be used to improve the simulated results and the parameterized accuracy.  相似文献   

12.
电极表面状态对原电池影响的热力学分析   总被引:3,自引:0,他引:3  
1前言我们知道,超细微粒及其材料具有许多优异的物理化学性质[1~6];这是因为随着物质分散度的增加,比表面积和表面能也相应增加,从而产生了强烈的表面效应,导致体系在分散状态时的物理化学性质与块状时相比发生了显著变化。我们知道,表面粗糙的金属容易发生电...  相似文献   

13.
谢祖 《高分子科学》1989,(2):183-188
A new method for the preparation of a soluble ladderlike polymethylsilsesquioxane with high molecular weight ((?)=10~5—10~6) and low molecular weight distribution (D=Mw/Mn) in common solvents instead of the formerly used toxic methylisobutylketone has been developed. The structure and macromolecular regularity were characterized by IR, X-ray diffraction, and ~(29)Si-NMR spectroscopy. The thermal property was studied by TGA and DSC.  相似文献   

14.
A new way for synthesizing styrenic type of chiral resins grafting to multidentate ligand has been found. The synthetic scheme is proved to be practical by means of elemental anaysis, IR spectra and metal adsorbility. The resolving power of the new chiral ligand resins coordinated with copper (Ⅱ) as stationary phases has been discussed based on HPLC, and some points of view about the compositions of mobil phase and mechanism of resolution are presented.  相似文献   

15.
高效液相色谱法测定邻氰基苄基膦酸二乙酯*许峰何大森宋跃群张禹应玲(浙江师范大学化学系浙江金华321004)关键词高效液相色谱邻氰基苄基膦酸二乙酯邻氰基苄基膦酸二乙酯(DCP)是生产荧光增白剂ER的重要中间体[1]。它由邻氰基甲苯光氯化,邻氰基氯苄酯化...  相似文献   

16.
用量子化学从头计算方法对1,6-环十二二烯-2,4,8,10四炔的几何结构和光谱性质进行了研究,在优先分子构型的基础上通过等键反应分析分析和自然键轨道方法研究了它的稳定性、成键情况和共轭性。结果表明,1,6-环十二二烯-2,4,8,10四炔是一个平面刚性分子,具有一定程度的稳定性,可能稳定存在。分子中的C≡C键与C=C键,C≡C键与C≡C健存在一定程度的共轭,分子可能具有芳香性。  相似文献   

17.
铁基超细粒子催化剂具有优良的F-T反应性能。本工作利用原位Mssbauer谱辅以XRD技术研究了含有钾助剂的F-T合成铁基超细粒子催化剂的结构与还原行为,考察了催化剂组成和第二金属组分(Mn,Zn,Mg)的影响。“纯”铁超细粒子催化剂在氢气中很容易经Fe_3O_4还原为零价铁。第二金属组分的引入,一方面阻碍了催化剂的还原,另一方面稳定了Fe~(2+)的存在而使其成为还原的主要中间相,这有利于反应条件下形成类尖晶石结构的活性相。对于Fe-Mn催化剂,上述效应随锰含量的增加而更趋显著。铁基超细粒子催化剂在氢气中的还原能力依“纯”Fe>Fe-Zn>Fe-Mn>Fe-Mg的顺序递减,这在一定程度上反映了铁与第二金属组分之间相互作用的强弱。  相似文献   

18.
在强酸性条件下,以薄层树脂相吸光光度法测定硅的新方法,本法灵敏度高(810=7.3×105L/molcm),比水相光度法提高16倍。精密度理想 (测定6.0g Si 6次,RSD=1.2%)。测定了高纯稀土中硅,线性范围0g/25ml~16g/25ml,检出限1.2g/L,回收率96%~101%。  相似文献   

19.
微量金属元素含量与高胆固醇致病关系的研究   总被引:1,自引:0,他引:1  
1 对象与方法 1.1 观察对象 住院冠心病人44例,男女各22名,年龄45~77岁,平均62.1岁.临床诊断标准符合WHO标准 ,即典型心绞痛,伴心电图ST段水平下移≥0.05mV,T波倒置.对照组42例,选择经体检,心电图、B超、血脂、血糖、肝、肾功能等各项检查,排除了与心脑血管有关的疾病的健康人 ,并在年龄、性别方面作了适当匹配.  相似文献   

20.
制备高碳醇用Cu-Fe系催化剂的活性相   总被引:2,自引:0,他引:2  
用共沉淀法制备了Cu-Fe系催化剂,它是由脂肪酸甲酯加氢制备高碳醇的新催化体系.催化剂经焙烧后的物相为CuO,γ-Fe2O3和MgO,形成了活性相的结构前驱.在反应条件下,CuO首先被还原为金属态的Cu0,然后γ-Fe2O3被还原为Fe3O4;Cu0和Fe3O4共同参与催化该反应.本文用XRD,TG-DTA和Mossbauer谱等手段,结合催化剂的活性测定,确定了催化剂的活性相为Cu0和Fe3O4;MgO可改变催化剂的电子结构和几何构型,起到重要的助催化作用  相似文献   

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