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1994 Volume 11 Issue 6
1994, 11(6): 1-6
Abstract:
The selectivity and sensitivity of SnO2 gas sensing material liave been improvedgreatly by application of nanotechnique and dopants.In this paper the recent advances inpreparation,doping and gas sensing mechanism of the SnO2 gas sensing material arereviewed。
The selectivity and sensitivity of SnO2 gas sensing material liave been improvedgreatly by application of nanotechnique and dopants.In this paper the recent advances inpreparation,doping and gas sensing mechanism of the SnO2 gas sensing material arereviewed。
1994, 11(6): 7-11
Abstract:
The solid state reactions of 2-aminopyrimidine (AP) with CuCl2·2H2O,CuBr2,CuSO4·5H2O and CuAc2·H2O at room or near room temperature result in the formation of three kinds of complexes with coordination ratio Cu/AP=1:2,1:1 and 2:1 respectively.The solid products were chracterized by elemental analysis,XRD,ICP,UV,ESR methods.The mechanism of this kind of reations and the effects of copper and the reagents were discussed.
The solid state reactions of 2-aminopyrimidine (AP) with CuCl2·2H2O,CuBr2,CuSO4·5H2O and CuAc2·H2O at room or near room temperature result in the formation of three kinds of complexes with coordination ratio Cu/AP=1:2,1:1 and 2:1 respectively.The solid products were chracterized by elemental analysis,XRD,ICP,UV,ESR methods.The mechanism of this kind of reations and the effects of copper and the reagents were discussed.
1994, 11(6): 12-16
Abstract:
Four noveI telluracarbocyanine dyes have been synthesized from quaternary ammonium iodides of benzotellurazole with ethyl orthoformate.The former was synthesized by treatment of 2,5,6.trimt1i1、yl benzotellurazole and 2-methyl-5-hydroxylbenzotellurazole with methyl or ethyl iodide,respectively.The visible absorption spectra of the dyes in different solvents were recorded.The effects of the solvents and substituents on the spectra of the dves are discussed.
Four noveI telluracarbocyanine dyes have been synthesized from quaternary ammonium iodides of benzotellurazole with ethyl orthoformate.The former was synthesized by treatment of 2,5,6.trimt1i1、yl benzotellurazole and 2-methyl-5-hydroxylbenzotellurazole with methyl or ethyl iodide,respectively.The visible absorption spectra of the dyes in different solvents were recorded.The effects of the solvents and substituents on the spectra of the dves are discussed.
1994, 11(6): 17-21
Abstract:
The stability of cationic and anionic polydimethylsiloxane latices towards acid and base was studied.It was found that the anionic latices were stable in the acid of concentration usually employed for catalytical polymerization.The stability of cationic latices was poor towards base,which is used as the catalyst of the polymerization.The limit sodium hydroxide concentration causing slow flocculation of cationic latices was lower than the concentration needed for the polymerization,so that the formation of large latex particles owing to flocculation could not be prevented during the emulsion polymerization.The transfer of a large part of the emulsifier from the aqueous phase to tpolysiloxane phase during the emulsion polymerization was also responsible for the formation of large latex particles.
The stability of cationic and anionic polydimethylsiloxane latices towards acid and base was studied.It was found that the anionic latices were stable in the acid of concentration usually employed for catalytical polymerization.The stability of cationic latices was poor towards base,which is used as the catalyst of the polymerization.The limit sodium hydroxide concentration causing slow flocculation of cationic latices was lower than the concentration needed for the polymerization,so that the formation of large latex particles owing to flocculation could not be prevented during the emulsion polymerization.The transfer of a large part of the emulsifier from the aqueous phase to tpolysiloxane phase during the emulsion polymerization was also responsible for the formation of large latex particles.
1994, 11(6): 22-26
Abstract:
The miscibility of the blends of polyethylene terephthalate (PET) with ethylene terephthalate-caprolactone random copolyesters (TCL) was examined by DSC,and a miscibility limit concerning ET content in the TCL copolyesters was obtained.The effects of ET contents in the TCL and the transesterification occurred at elevated temperature on the miscibility of the blend system are discussed.
The miscibility of the blends of polyethylene terephthalate (PET) with ethylene terephthalate-caprolactone random copolyesters (TCL) was examined by DSC,and a miscibility limit concerning ET content in the TCL copolyesters was obtained.The effects of ET contents in the TCL and the transesterification occurred at elevated temperature on the miscibility of the blend system are discussed.
1994, 11(6): 27-31
Abstract:
A series of 1,2,4,6-tetrasubstituted pyridinium tetrafluoroborates were svnthesized and their plant growth regulating activities were examined.Some of them have been found to be effective in regulating the growth of rice and green gram.Among them,1-(4,6-dimethylpyrimidin-2-yl)-2,4,6-triphenylpyridinium tetrafluoroborate was the most effective in inhibiting the growth of rice,Preliminary studv sbws that tl、e11eterocvclic radical at 1-position of parent pyridine enhances the growth inhibiting activity to rice,and alkyl containing oxygen atom at 1-position of parent pyridine enhances the growth inhibiting activity togreen gram.
A series of 1,2,4,6-tetrasubstituted pyridinium tetrafluoroborates were svnthesized and their plant growth regulating activities were examined.Some of them have been found to be effective in regulating the growth of rice and green gram.Among them,1-(4,6-dimethylpyrimidin-2-yl)-2,4,6-triphenylpyridinium tetrafluoroborate was the most effective in inhibiting the growth of rice,Preliminary studv sbws that tl、e11eterocvclic radical at 1-position of parent pyridine enhances the growth inhibiting activity to rice,and alkyl containing oxygen atom at 1-position of parent pyridine enhances the growth inhibiting activity togreen gram.
1994, 11(6): 32-36
Abstract:
The mixed lithium-lanthnum-titanium oxide catalysts have been prepared from different Li-containing compounds (LiNO3,Li2SO4) for oxidative coupling of methane,The XRD,IR,XPS,and BET resuIts showed that LiLa0.5 Ti0.5 O2+λ catalysts prepared from LiNO3 possessed a higher activity and space velocity,while those from LiSO4 possessed amuch higher C2 selectivity,but lower activity and space velocity.The deactivation of LILa0.5 Ti0.5 O2+λ catalysts prepared from LiNO3 is mainly caused by the loss of surface lithium.In the course of the coupling reaction the bulk lithium diffuses to the surface,leading to the decomposition of active phase containing lithium and lowering the amount of oxygen vacancies.In order to combine the advantages of both catalysts prepared from LiNO3 and Li2SO4 and to fix the surface lithium a novel preparation method with impregnation in (NH4)2SO4 is proposed.
The mixed lithium-lanthnum-titanium oxide catalysts have been prepared from different Li-containing compounds (LiNO3,Li2SO4) for oxidative coupling of methane,The XRD,IR,XPS,and BET resuIts showed that LiLa0.5 Ti0.5 O2+λ catalysts prepared from LiNO3 possessed a higher activity and space velocity,while those from LiSO4 possessed amuch higher C2 selectivity,but lower activity and space velocity.The deactivation of LILa0.5 Ti0.5 O2+λ catalysts prepared from LiNO3 is mainly caused by the loss of surface lithium.In the course of the coupling reaction the bulk lithium diffuses to the surface,leading to the decomposition of active phase containing lithium and lowering the amount of oxygen vacancies.In order to combine the advantages of both catalysts prepared from LiNO3 and Li2SO4 and to fix the surface lithium a novel preparation method with impregnation in (NH4)2SO4 is proposed.
1994, 11(6): 37-40
Abstract:
Nine novel dinuclear complexes of transition metal ions with pentabenzimi-dazolylmethyl diethylene triamine are reported.The results of variable temperature magnetic susceptibility of the complexes indicated that an antiferromagnetic exchnge interaction exists between metal ions in dinuclear unit.Themagnitude of thespin interaction (J) of the complexes had the following sequence |JCu2+,S=(1/2)|>|JNi2+,S=1|>|JCo2+,S=(3/2)|>|JMn2+,S=(2/5)|. The preliniinflry rexults of bioassay shwed that some complexeshd antitumor activities in vitro,regulating plant growth and fungicidal activities.
Nine novel dinuclear complexes of transition metal ions with pentabenzimi-dazolylmethyl diethylene triamine are reported.The results of variable temperature magnetic susceptibility of the complexes indicated that an antiferromagnetic exchnge interaction exists between metal ions in dinuclear unit.Themagnitude of thespin interaction (J) of the complexes had the following sequence |JCu2+,S=(1/2)|>|JNi2+,S=1|>|JCo2+,S=(3/2)|>|JMn2+,S=(2/5)|. The preliniinflry rexults of bioassay shwed that some complexeshd antitumor activities in vitro,regulating plant growth and fungicidal activities.
1994, 11(6): 41-44
Abstract:
A comblike polymer based on methyl vinyl etherlmaleic anhydride copolymer backbone and with oligo-oxyetllylene side chins was synthesized for the first time.A two-step esterification has been carried out for polymer synthesis:reacting maleic anhydride with PEGME in methylethyl ketone at 80℃ for 24hurs and then reacting the product obtained with methanol in the presence of p-toluene sulfonic acid at 60℃ for 24 hours.The structure of the product was confirmed by IR,13C NMR and elemental analysis.
A comblike polymer based on methyl vinyl etherlmaleic anhydride copolymer backbone and with oligo-oxyetllylene side chins was synthesized for the first time.A two-step esterification has been carried out for polymer synthesis:reacting maleic anhydride with PEGME in methylethyl ketone at 80℃ for 24hurs and then reacting the product obtained with methanol in the presence of p-toluene sulfonic acid at 60℃ for 24 hours.The structure of the product was confirmed by IR,13C NMR and elemental analysis.
1994, 11(6): 45-48
Abstract:
The semiconducting SnO2 powder sized in 0.02~10μm was degassed completely in high vaccum and pressurized at above 40MPa to give repeatable values of d.c.resistance.For SnO2 undoped by Sb the d.c.resistance values obtained were changed with the cooling process used.The results have been discussed in terms of the structure of the polycrystalline of SnO2.
The semiconducting SnO2 powder sized in 0.02~10μm was degassed completely in high vaccum and pressurized at above 40MPa to give repeatable values of d.c.resistance.For SnO2 undoped by Sb the d.c.resistance values obtained were changed with the cooling process used.The results have been discussed in terms of the structure of the polycrystalline of SnO2.
1994, 11(6): 49-52
Abstract:
Eight title compounds Ia~h were synthesized by nucleophilic substitution of alky ldichloro phosphorate by sodium-4-(quinoxalyl-2-oxy) phenolate followed by reaction with secondary amines in polar organic solvent.Their structures were characterized by elemental analysis,IR,1H NMR,31P NMR,and MS measurements and their herbicidal activities were tested.
Eight title compounds Ia~h were synthesized by nucleophilic substitution of alky ldichloro phosphorate by sodium-4-(quinoxalyl-2-oxy) phenolate followed by reaction with secondary amines in polar organic solvent.Their structures were characterized by elemental analysis,IR,1H NMR,31P NMR,and MS measurements and their herbicidal activities were tested.
1994, 11(6): 53-56
Abstract:
A large number of defects were formed on the surface of MgO crystal on shock wave treatment.The microdistortion value of crystal increased obviously and some F colour centers are considered to be formed.The shock wave treated MgO exhibited a high erethane conversion and ethylene selectivity in the oxidative dehydrogenation of ethane,The effects of reaction temperature,time and space velocity in dehydrogenation have been examined.A possible model for structure modification and a catalytic mechanism of MgO crystal on the shock wave treatnient have been proposed.
A large number of defects were formed on the surface of MgO crystal on shock wave treatment.The microdistortion value of crystal increased obviously and some F colour centers are considered to be formed.The shock wave treated MgO exhibited a high erethane conversion and ethylene selectivity in the oxidative dehydrogenation of ethane,The effects of reaction temperature,time and space velocity in dehydrogenation have been examined.A possible model for structure modification and a catalytic mechanism of MgO crystal on the shock wave treatnient have been proposed.
1994, 11(6): 57-60
Abstract:
A bismaleimide with polysiloxane segment in main chain was synthesized and characterized by FTIR、NMR、GPC、DTA and TG.
A bismaleimide with polysiloxane segment in main chain was synthesized and characterized by FTIR、NMR、GPC、DTA and TG.
1994, 11(6): 61-64
Abstract:
Seven mercaptoacetates were catalytically prepared on modified HZSM-5 in yield about 90%,The high catalytical activity of modified HZSM-5 has been discussed on the results of NMR spectra.
Seven mercaptoacetates were catalytically prepared on modified HZSM-5 in yield about 90%,The high catalytical activity of modified HZSM-5 has been discussed on the results of NMR spectra.
1994, 11(6): 65-68
Abstract:
The thermoplastic polyester-polyurethane elastomers were synthesized from poly-hexamethylene carbonate,polytetramethylene adipate,diphenyl methane-4,4'disocyanate and 1,4-butylene-glycol.Their glass transition temperature,mechanical property,hydrolytic stability and rheological property have been studied.The results show that the Tg,and the apparent viscosity of tlie polymer melt decreased vVith the increase of the polycarbonate content.The processability and hydrolytic stability of the elastomer were improved.
The thermoplastic polyester-polyurethane elastomers were synthesized from poly-hexamethylene carbonate,polytetramethylene adipate,diphenyl methane-4,4'disocyanate and 1,4-butylene-glycol.Their glass transition temperature,mechanical property,hydrolytic stability and rheological property have been studied.The results show that the Tg,and the apparent viscosity of tlie polymer melt decreased vVith the increase of the polycarbonate content.The processability and hydrolytic stability of the elastomer were improved.
1994, 11(6): 69-72
Abstract:
The deep oxidation kinetics of toluene over PtINM and Pd/NM catalysts was studied in the presence of large excess of oxygen.The catalytic activity of Pt/NM was higher than that of Pd/NM.The rate of the catalytic oxydation could be described by equation:r=(KC)/((1+bC)2) The aparent activation energy (△E) and the heat of absorption (Q) of toluene on the ca-talyst surface were calculated as 49.9(kJ/mol),-29.6(kJ/mol) for Pt/NM and 94.2(kJ/mol),-19.1(kJ/mol) for Pd/NM respectively.
The deep oxidation kinetics of toluene over PtINM and Pd/NM catalysts was studied in the presence of large excess of oxygen.The catalytic activity of Pt/NM was higher than that of Pd/NM.The rate of the catalytic oxydation could be described by equation:r=(KC)/((1+bC)2) The aparent activation energy (△E) and the heat of absorption (Q) of toluene on the ca-talyst surface were calculated as 49.9(kJ/mol),-29.6(kJ/mol) for Pt/NM and 94.2(kJ/mol),-19.1(kJ/mol) for Pd/NM respectively.
1994, 11(6): 73-76
Abstract:
Three new-type complexes,[AuL2]OH (HL:1-hydroxy-2-(1H)-pyridine-thione and its 3-and 4-met hyl-derivatives),were prepared.They have been characterized by elemental analysis,UV,IR,1H NMR,molar conductance and TG-DTA-DTG.Their redox properties have been investigated by cyclic voltammetry.The complexes having CH3 substituent in pyridine ring showed a fairly high antibacterial activity.
Three new-type complexes,[AuL2]OH (HL:1-hydroxy-2-(1H)-pyridine-thione and its 3-and 4-met hyl-derivatives),were prepared.They have been characterized by elemental analysis,UV,IR,1H NMR,molar conductance and TG-DTA-DTG.Their redox properties have been investigated by cyclic voltammetry.The complexes having CH3 substituent in pyridine ring showed a fairly high antibacterial activity.
1994, 11(6): 77-80
Abstract:
The alpha-amino and alpha-carboxyl group in glutamic acid (Glu) were protected by specific coprotection method,γ-Glu-Ser-Gly was synthesized by the liquid peptide method.The prepared mimic tripeptides were used for the chemical mutation of PMSF and H2Se,as well as γ-Glu-SeCys-Gly,The structures of mimic tripeptides were determined by elemental analysis and amino acid analysis.The valency and quantity of Se in mimic tripeptides were determined.
The alpha-amino and alpha-carboxyl group in glutamic acid (Glu) were protected by specific coprotection method,γ-Glu-Ser-Gly was synthesized by the liquid peptide method.The prepared mimic tripeptides were used for the chemical mutation of PMSF and H2Se,as well as γ-Glu-SeCys-Gly,The structures of mimic tripeptides were determined by elemental analysis and amino acid analysis.The valency and quantity of Se in mimic tripeptides were determined.
1994, 11(6): 81-84
Abstract:
The fast triangular wave and potential sweep techniques were used to study the anodic film of Cu formed in 12.0 mol/L H3PO4.The solid film formed on copper during electropolishing is a n-type semiconductor and has a depth of 0.75~5.6nm and capacitance of 7~12 μF/cm2,EDAX and XPS results showed that the predominate constitution of the filmwas Cu2O and Cu2O·H2O.The mechanism of the electropolishing has been discussed.
The fast triangular wave and potential sweep techniques were used to study the anodic film of Cu formed in 12.0 mol/L H3PO4.The solid film formed on copper during electropolishing is a n-type semiconductor and has a depth of 0.75~5.6nm and capacitance of 7~12 μF/cm2,EDAX and XPS results showed that the predominate constitution of the filmwas Cu2O and Cu2O·H2O.The mechanism of the electropolishing has been discussed.
1994, 11(6): 85-88
Abstract:
The oxidation mechanism of sulfur dioxide on gold and ruthenium electrodes has been studied by chronopotentiometry,clironoamperometry and the steady-state method.The kinetic parameters in sulfur dioxide oxidation have been calculated and a possible oxidation mechanism has been proposed.
The oxidation mechanism of sulfur dioxide on gold and ruthenium electrodes has been studied by chronopotentiometry,clironoamperometry and the steady-state method.The kinetic parameters in sulfur dioxide oxidation have been calculated and a possible oxidation mechanism has been proposed.
1994, 11(6): 89-91
Abstract:
The deep purifing system is made up from 4 kinds of foam plastics column containing respectively active MnO2,NaBiO3,cadmium (zinc) diethylaminothiocarbamate and dimethylglyoxime in series.When a solution of zinc or cadmium sulfate flows through thesvstem the content of Fe2+,Cr3+,Mn2+,Cu2+,Pb2+,Co2+ and Ni2+ in it can be decreased rapidly and simply from 1~10μg/g to less than 0.1~0.5μg/g.
The deep purifing system is made up from 4 kinds of foam plastics column containing respectively active MnO2,NaBiO3,cadmium (zinc) diethylaminothiocarbamate and dimethylglyoxime in series.When a solution of zinc or cadmium sulfate flows through thesvstem the content of Fe2+,Cr3+,Mn2+,Cu2+,Pb2+,Co2+ and Ni2+ in it can be decreased rapidly and simply from 1~10μg/g to less than 0.1~0.5μg/g.
1994, 11(6): 92-94
Abstract:
The fluorescence properties of Eu (Ⅲ)-PhenNO-TTA-emulsifier OP system have been studied (phen NO:phenanthroline-N-oxide,TTA:thenoyltrifluoroacetone).The system has been used for determination of trace amount of Eu (Ⅲ) in some samples with satisfactory results.The determination limit was observed of7.0×10-14mol/L.
The fluorescence properties of Eu (Ⅲ)-PhenNO-TTA-emulsifier OP system have been studied (phen NO:phenanthroline-N-oxide,TTA:thenoyltrifluoroacetone).The system has been used for determination of trace amount of Eu (Ⅲ) in some samples with satisfactory results.The determination limit was observed of7.0×10-14mol/L.
1994, 11(6): 95-97
Abstract:
Titanium ion was iniplanted into surface of lead-4% antimony alloy for lead acid battery usage to improve the anticorrosion property of the alloy.The results showed that a favourable value for Ti ion implanation was 60keV.
Titanium ion was iniplanted into surface of lead-4% antimony alloy for lead acid battery usage to improve the anticorrosion property of the alloy.The results showed that a favourable value for Ti ion implanation was 60keV.
1994, 11(6): 98-100
Abstract:
The title compound was synthesized by treatment of 1-bromododecane with azacycloheptan-2-one in the presence of potassium hydroxide in toluene in yield of 88%~92%。
The title compound was synthesized by treatment of 1-bromododecane with azacycloheptan-2-one in the presence of potassium hydroxide in toluene in yield of 88%~92%。
1994, 11(6): 101-103
Abstract:
The cyclization of 3-(substituted anilino-methylene)-6-methyl-α,γ-Pyronone was carried out in the presence of hydrochloric acid.Seven N-substituted phenyl-6-methyl-4-oxo-dihydro-pyridine-3-carboxylic acids were synthesized by cyclization with their structures being identified by elemental and NMR analyses.
The cyclization of 3-(substituted anilino-methylene)-6-methyl-α,γ-Pyronone was carried out in the presence of hydrochloric acid.Seven N-substituted phenyl-6-methyl-4-oxo-dihydro-pyridine-3-carboxylic acids were synthesized by cyclization with their structures being identified by elemental and NMR analyses.
1994, 11(6): 104-105
Abstract:
A series of 1-aroyl-3-(4-benzosulfonamide)-thioureas were synthesized by reacting aroylisothiocyanate with sulfanilamide in anhydrous acetone.
A series of 1-aroyl-3-(4-benzosulfonamide)-thioureas were synthesized by reacting aroylisothiocyanate with sulfanilamide in anhydrous acetone.
