A FAD-SMT Model of Large Scale Liquid Adsorption Chromatography

The paper proposes a FAD-SMT model of large-scale liquid chromatography by which a continuous equation of chromatographic separation is decomposed into a convection dispersion partial differential equation and a set of ordinary differential equations. The numerical method for the FAD-SMT model is established. The stability and the convergence condition of numerical solution, and the choice of time and space interval are discussed. The FAD-SMT model is used to simulate liquid adsorption chromatography and cycling adsorption chromatography. Results show that the elution curves calculated by FAD-SMT model are good agreement with the experimental elution curves of the separation of glucose and fructose, the separation of sucrose and reducing sugar and the separation of mannitol and sorbitol. The result of parameter sensitivity analysis shows that the chromatographic elution curves are more sensitive to the changes of the parameter ai in Langmuir isotherms than to the changes of other parameters in the studied system.     

Atom Transfer Radical Polymerization of Methyl Methacrylate with α,α-Dichlorotoluene or α,α,α-Trichlorotoluene as Initiator

lnAtomTransferRadicalPolymerization(ATRP),whichisanew"living"/contr0lledradicalp0lymerizati0ntechniquedevel0pedindependentlybyMatyjaszewskieIallandSawam0t0eIaP,anyalkyIhalidewithactivatedsubstituents0na-carbonsuchasaryl,carb0nyl0rallylcanbeusedasinitiatoe.Benzy1haIideandpolymerswithbenzylhalideendgr0upwerereportedtobeefficientinitiator0rmacroinitiatorfortheATRPofstyrene".H0wever,whenbenzylhalidewasusedt0initiateMMAp0Iymerization,itwasfoundthattheinitiationefficiencywasveryIowinourlabo…     

The Assembly and Molecular Structure of a Novel One-dimensionalCyanide-bridged [Ni(pn)_2Ni(CN)_4]_n·nH_2 O Complex

IntroductionSincetheearlyworkofPedersen',CramZandLehn',molecularassemblyhasattractedmuchattentionfromscientistsofdifferentareas,rangingfromchemistrytosolid-statephysicsandbiology,becauseofthepotentialimpactonmaterialscience,catalysisandmetallo-biochemistry#.ThepreparationandstUdyofpolynuclear,cyanide-bridgedmetalcomplexeshaveattractedconsiderableinterestoverthepastdecades-I3.Cyanide-bridgedpolynuclearcomplexesaresuitablefortheconstructionofsuchdevicestoobtainmoleculescapableofestablishingspe…     

Fragmentation Reactions of Adduct Ions [M CH_3CO]~ of IsomericPhenylenediamines

Acetonehasbeenusedasachemicalionization(CI)reagentgasinaconventionalionsourceandfoundtoproducenumerousreagentions,whichreactwithdifferentclassesofcompoundstoformavarietyofadductions,mostlyusedtogainmolecularmasses,stereochemicalstructureinformation,toassistinthedifferentiationofvariousisomersandalsotogivecharacteristicreactionwithdifferentfunctionalgroups'w'.Intramolecularfunctionalgroupinteractionsplayimportantrolesinthedissociationreactionsofgas-phaseions6".Theadductions[M CH,CO] formedbyi…     

适用于改换介质的简易电解池设计及其电位溶出分析的应用研究

设计制作了用于改换介质的简易电解池,并以旋转圆盘玻碳电极为工作电极,研究了其用于电位溶出分析改换溶出介质的可行性。以同时测定Ｐｂ＾２＋、Ｃｄ＾２＋为例,试验了改换溶出介质的条件。结果表明,改换介质可消除共存离子的干扰,只要选择合适的溶出介质,可有效地提高测定方法的分辨率和灵敏度。此方法用于矿样中铅和镉的同时测定,结果满意。     

丁苯橡胶的阳离子环化

应用一氯二乙基铝和苄基氯催化剂体系进行了丁苯橡胶的阳离子环化反应。研究了反应温度、苄基氯／一氯二乙基铝比例、溶剂、原胶浓度对环化的影响。发现通过控制苄基氯／一氯二乙基铝比,可在高温（１２０℃）、高原胶浓度（２～４％ｗ／ｖ）下进行丁苯橡胶的环化,制得特性粘度较原胶有大幅度降低,可溶性无凝胶的环化丁苯胶。通过对红外光谱、＾１Ｈ－ＮＭＲ谱初步解析,证实了环化反应的发生。     

Topological structures of tetrahedral (Td and T) fullerenes with hexagonal and triangular faces and their vibration and NMR spectra

On analyzing the topological structures of the three types of tetrahedral fullerenes (which consist only of triangles and hexagons), (1) C _n (T _d ,n=12h ²; h=1,2,…), (2) C _n (T _d ,n=4h ²;h=1,2,…), and (3) C _n (T,n=4(h ²+hk+k ²);h>k,h,k=1,2,…), we have obtained theoretically the Infrared and Raman active modes by means of the derived formulas for the decomposition of their nuclear motions into irreducible representations, and the ¹³C NMR spectra with natural abundance for ¹³C by using the distribution functions for all of the tetrahedral (T _d and T) fullerenes, respectively. Received: 25 May 1998 / Accepted: 30 July 1998 / Published online: 23 November 1998     

一步法合成取代-1,2-苯醌类化合物

应用固定化多酚氧化酶催化的氧化-迈克尔加成反应,一步合成了4,5-二取代-1,2-苯醌类化合物:4,5-N,N-二(苯胺基)-1,2-苯醌,4,5-N,N-二(对甲苯胺基)-1,2-苯醌,4,5-N,N-二(间氯苯胺基)-1,2-苯醌,4,5-N,N-二(对溴苯胺基)-1,2-苯醌。用化学法(I_2—KI)进行氧化-迈克尔加成反应也成功地合成了4,5-二取代-1,2-苯醌类化合物。应用紫外光谱方法证明了氧化-迈克尔加成反应的机制。     

六氟磷酸二(2,2′-联吡啶)(2,2′-联吡啶-4,4′-二羧酸)合钌(Ⅱ)的二维核磁共振谱分析

利用核磁共振氢谱和碳谱研究了电化学探针六氟磷酸二(2,2′-联吡啶)(2,2′-联吡啶-4,4'-二羧酸)合钌(Ⅱ)的立体结构,并通过二维1H-1H同核相关及1H-13C异核相关技术对其氢谱和碳谱进行了归属.     

Sasaki空间型M-2n+1(c)中的极小积分子流形

本文重新给出了Ｓａｓａｋｉ空间型中极小积分子流形的关于Ｒｉｃｉ曲率的内蕴刚性定理,它改进了［２］及［３］中的有关定理,而且取消了［３］中关于维数的限制．对３维极小积分子流形,又给出了一个关于数量曲率的内蕴刚性定理．