漆树漆酶的催化氧化作用 (ⅹⅢ)──Fe~(2+)离子对漆酶催化氧化反应的影响()

以５,６－二溴－２,３－二氰基氢醌为底物,在ｐＨ４．５０条件下,用分光光度法考察了ＦｅＳＯ４对漆树漆酶催化氧化反应的影响．结果表明,在本文实验条件下ＳＯ２－４离子对酶促反应的影响基本可以忽略,而Ｆｅ２＋离子对漆酶的催化氧化反应则有明显的竞争性抑制作用．研究证实,Ｆｅ２＋离子的抑制作用是通过它还原酶促反应的产物半醌自由基阴离子来实现的     

一种检测NO的修饰电极

报道了[Fe(Sal₂en)]²⁺的咪唑加合物对NO电氧化的影响.实验表明,它将[Fe(Sal₂en)]²⁺对NO的电催化氧化活性提高T₂倍.过量咪唑会降低[Fe(Sal₂en)]²⁺对NO的催化活性.证实了NO的电催化氧化形成NO[Fe(Sal₂en)]²⁺中间体的推断.用制得的修饰电极测定NO,当c(NO)在3×10^-6～2×10^-9mol/L时,有良好线性关系,相对标准偏差小于0.5％,线性相关系数为0.9994,检测限为2×10^-9mol/L.满足生理分析的要求.     

Fe-Al络合催化苯乙烯-马来酸酐交替共聚

应用Ｆｅ（ａｃａｃ）３ Ａｌ（ｉ Ｂｕ）３（ａｃａｃ＝乙酰丙酮）催化苯乙烯 马来酸酐共聚,制得富于交替的白色粉末共聚物．共聚反应动力学研究表明,共聚反应与单体浓度呈一级关系,表观活化能为４８６ｋＪ／ｍｏｌ．     

Surface recombination in breakdown time delay experiments: Effect of different cathode materials

The late afterglow in nitrogen with iron electrode is studied by the breakdown time delay method, i.e., by measuring the breakdown time delay t_d as a function of the afterglow time . It is proposed that the cause of the secondary electrons initiating the breakdown is the energy of the surface recombination of nitrogen atoms on the iron electrode. The gas-phase and macrokinetic diffusive models are used to describe the experimental breakdown time delay data. By fitting the theoretical curve to the experimental data: (1) it has been confirmed that the recombination on the molybdenum glass is of the second order and the value of the surface recombination coefficient is determined at 4 mbar; (2) it has been shown that the surface recombination on the iron electrode is of the second order, and the effective recombination coefficients are determined; (3) the analytical form of the recombination coefficient as a function of the adsorption characteristics of surfaces and the pressure of the parent gas has been derived. In addition, the orders of surface recombination on the molybdenum-, aluminum-, and gold-plated electrode were determined by the same method.     

用MES及XRD研究FT合成催化剂的活性结构

采用穆斯堡尔谱及Ｘ光衍射法研究了共沉淀法制备的不同Ｆｅ／Ｍｎ比催化剂在焙烧、合成气还原及ＦＴ反应后体系相结构的变化。结果表明：锰助剂的加入使催化本相由铁磁性逐渐转化为超顺磁性，相应使催化剂还原逐渐难，Ｍｎ助剂促进了ＦＴ合成反应进行。反应性能与Ｆｅ／Ｍｎ尖晶石（Ｆｅ１－ｙＭｎｙ）３Ｏ４组成含量及式中ｙ大小密切相关，与ＭｎＣｏ３及ＭｎＯ的存在也有一定关系。富铁催化剂中Ｍｎ主要起电子助剂作用，而富锰催化     

STUDY OF THE COPRECIPITATED IRON/MANGANESE FISCHER-TROPSCH CATALYSTS

IntroductionInFTsynthesis,metalMnhasbeenregardedasanicepromotertoincreaselightolefinselectivity.Coprecipitationhasbeenusedextensivelyinthepreparationofcommercialcatalysts.AnumberofpublicationsdealingwiththerelationbetWcenphysical-chemistry'proPertiesofcatalystsandFTs}nthesishaveappeared,butdifferentcatal})stcompositionsandpreparationconditi0nsmakedifferentconclusions.Therearetu)omainrespects.0neisthatcarelystswithhighacivityandolefinselectivityhavedifferentMMieratiovaryingoverawiderange(Mn…     

CATALYTIC CRACKING OF LIGHT ALKANES IN THE PRESENCE OF O_2 AND SELECTIVE CONTROL OF OLEFIN PRODUCTS

lntroductionThesmallolefinslikeethylene,propeneandbutenearethec0mmerciallydesirablepetrochemicalfeedstocksandarefoundincreasingusageinchemicalindustry.Theyareusuallyobtainedfromthepyrolysis0fpetroleumhydrocarb0nswithsteaInatveryhightemPeratUreandarealsoavailablefromFCCprocess.TheimProvedFCCcatalystforeIhancingtheolefinproducthasbeenreportedll].However,FCCisalrnostimPossiblefortheshortchainalkanefeedstockscutfrompetroleum0robtuinedfromrefinerygasornatUralgassincecrackingofhydrocarbonsbeco…     

Fe_3(CO)_9(μ_3-S)_2的P(SR)Cl_2和P(SR′)_3取代物的合成和结构研究

用P(SR)Cl_2和P(SR′)_3作n-酸配体,分别与Fe_3(CO)_9(μ_3-S)_2进行取代反应,得到6种新的一取代产物Fe_3(CO)_8(μ_3-S)_2L和3种新的二取代产物Fe_3(CO)_7(μ_3-S)_2L_2,并对它们进行了IR、~1H NMR和MS表征,测定了其中一种取代物Fe_3(CO)_8(μ_3-S)_2[P(SC_6H_5)Cl_2]的分子和晶体结构。     

H2O−D2O solvent isotope effect in the volume behavior of some high-charge high-size electrolytes

The apparent molar volumes V of KCl, BaCl₂, K₂SO₄, LaCl₃, Co(en)₃Cl₃ [Tris(ethylenediamine)cobalt(III) chloride], K₃Co(CN)₆, K₃Fe(CN)₆, K₄Fe(CN)₆, and Ba₃[Co(CN)₆]₂ have been determined at 25°C in both light and heavy water. The V values in D₂O are systematically lower and increase more rapidly with salt concentration than the V in H₂O. The volume of transfer from H₂O to D₂O as well as the partial molar volume at infinite dilution in both solvents have also been calculated. These results together with literature values for other electrolytes were used to estimate both of these quantities for D₂O solutions of individual ions. The predictions of ion hydration models and ion-ion interactions are compared with experimental observations.