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1992 Volume 9 Issue 4
1992, 9(4): 1-7
Abstract:
The recent development of shock wave chemistry in condensed matter is briefly revie wed. The peculiarities of shock wave induced chemical reactions were discussed. Some possible applications were listed, Including synthesis of superhard materials, manufacture and processing of highteeh ceramics, compaction of amorphous metals, activation add synthesis of inorganic substances, shock wave induced reactions of organic compounds.
The recent development of shock wave chemistry in condensed matter is briefly revie wed. The peculiarities of shock wave induced chemical reactions were discussed. Some possible applications were listed, Including synthesis of superhard materials, manufacture and processing of highteeh ceramics, compaction of amorphous metals, activation add synthesis of inorganic substances, shock wave induced reactions of organic compounds.
1992, 9(4): 8-12
Abstract:
Lanthanide complexes with bisbenzoylacetone-ethylenedimine(L) have been synthesized for the first timc. These compounds have the general formula Ln2(L)3(NO3)6·2H2O, where Ln=La, Ce,Pr,Nd, Sm,Gd, Dy, Er, On the basis of UV, IR, HNMR, TG-DTA and also from molar conductance measurements the possible structure of the complexes has been proposed.
Lanthanide complexes with bisbenzoylacetone-ethylenedimine(L) have been synthesized for the first timc. These compounds have the general formula Ln2(L)3(NO3)6·2H2O, where Ln=La, Ce,Pr,Nd, Sm,Gd, Dy, Er, On the basis of UV, IR, HNMR, TG-DTA and also from molar conductance measurements the possible structure of the complexes has been proposed.
1992, 9(4): 13-16
Abstract:
Poly(styrene-chloromethyl styrene-acrylie acid) latex particles of high specific gravity were prepared by emulsifier-free emulsion polymerization. Copolymerization and the properities of latex particles were effectively controlled by varying the molar ratio of monomers. The stable latex microspheres with excellent monodispersity and clear surface were obtained.
Poly(styrene-chloromethyl styrene-acrylie acid) latex particles of high specific gravity were prepared by emulsifier-free emulsion polymerization. Copolymerization and the properities of latex particles were effectively controlled by varying the molar ratio of monomers. The stable latex microspheres with excellent monodispersity and clear surface were obtained.
1992, 9(4): 17-20
Abstract:
The ternary complexes of 1,10-phenanthroline-N-oxide and picric acid with Mg, Ca, Sr and Ba have been synthesized in a non-aqueous medium. The complexes were characterized by elemental analysis, molar conductances, IR, Raman and 1H NMR spectra and DTATG techniques.
The ternary complexes of 1,10-phenanthroline-N-oxide and picric acid with Mg, Ca, Sr and Ba have been synthesized in a non-aqueous medium. The complexes were characterized by elemental analysis, molar conductances, IR, Raman and 1H NMR spectra and DTATG techniques.
1992, 9(4): 21-25
Abstract:
The extraction equilibrium of Sc(Ⅱ), Y(Ⅲ), Ln(Ⅲ)(Ln=Ho, Er, Yb, Lu) and Fe(Ⅲ) from HCl solutions with H(DEHP) in n-octane has been investigated. The order of extractability of the above elements is found as follows:Sc >> Fe > Lu > Yb > Er > Y > Ho. Y lies between Ho and Er. It is possible to separate Se(Ⅱ) from Fe(Ⅲ) and Ln(Ⅲ), and heavy lanthanide(Ⅲ) each other by H(DEHP).By the methods of slope analysis, saturation capacity and IR, NMR·spectra, the composition of extracted complexes of Sc(Ⅲ) and Yb(Ⅲ) with H(DEHP) has been determined to be Sc(HL2)3 and YbL3(HL2). The extraction mechanism of rare earths(Ⅲ) has been obtained.The equilibrium constants and thermodynamic functions of extraction reactions have also been calculated.
The extraction equilibrium of Sc(Ⅱ), Y(Ⅲ), Ln(Ⅲ)(Ln=Ho, Er, Yb, Lu) and Fe(Ⅲ) from HCl solutions with H(DEHP) in n-octane has been investigated. The order of extractability of the above elements is found as follows:Sc >> Fe > Lu > Yb > Er > Y > Ho. Y lies between Ho and Er. It is possible to separate Se(Ⅱ) from Fe(Ⅲ) and Ln(Ⅲ), and heavy lanthanide(Ⅲ) each other by H(DEHP).By the methods of slope analysis, saturation capacity and IR, NMR·spectra, the composition of extracted complexes of Sc(Ⅲ) and Yb(Ⅲ) with H(DEHP) has been determined to be Sc(HL2)3 and YbL3(HL2). The extraction mechanism of rare earths(Ⅲ) has been obtained.The equilibrium constants and thermodynamic functions of extraction reactions have also been calculated.
1992, 9(4): 26-30
Abstract:
4-Thia-6-dimethylaminohexyltrimethoxysilane was synthesized by condensation of γ-mereaptopropyltrimethoxysilane and β-chloroethyldimethylamine hydrochloride in the presence of sodium methoxide. The new silicon monomer was subjected to hydrolysis and immobilization on fumed silica, followed by reaction with potassium chloroplatinite to give the title platinum complex. The complex was found to be an effective catalyst for the hydrosilylation of olefins with triethoxysilane.The influences of temperature, the amount of the complex used,and the kind of olefins on the catalytic activity were investigated.
4-Thia-6-dimethylaminohexyltrimethoxysilane was synthesized by condensation of γ-mereaptopropyltrimethoxysilane and β-chloroethyldimethylamine hydrochloride in the presence of sodium methoxide. The new silicon monomer was subjected to hydrolysis and immobilization on fumed silica, followed by reaction with potassium chloroplatinite to give the title platinum complex. The complex was found to be an effective catalyst for the hydrosilylation of olefins with triethoxysilane.The influences of temperature, the amount of the complex used,and the kind of olefins on the catalytic activity were investigated.
1992, 9(4): 31-34
Abstract:
The critical overlap concentration (C*) and the critical entanglement concentration CB* of linear polystyrene (LPS) and branched polystyeene (BPS) have been disseussed. The values of C* and CE* were calculated according to the Graessley and Klein equation C*=0.77/[η], C*=1.08/[η], respectively. The results showed that the C* and CE* of branched polystyrene were larger than those of linear polystyrene.
The critical overlap concentration (C*) and the critical entanglement concentration CB* of linear polystyrene (LPS) and branched polystyeene (BPS) have been disseussed. The values of C* and CE* were calculated according to the Graessley and Klein equation C*=0.77/[η], C*=1.08/[η], respectively. The results showed that the C* and CE* of branched polystyrene were larger than those of linear polystyrene.
1992, 9(4): 35-40
Abstract:
The quantitative structure-activity relationships (QSAR) have been studied between larvicidal activity against second instar larvae of Culex Pipiens Pallens and substituted 2-chlorobenzoyl phenyl urea or thiourea. From QSAR study, some important structure factors influencing the larvicidal activity of this series are found. Electronic parameter is the most important factor influencing the lavicidal activity, and some compounds hare the same insecticidal activity as 2,6-difluorobenzoyl-4-chlorophenyl urea(PH6040).
The quantitative structure-activity relationships (QSAR) have been studied between larvicidal activity against second instar larvae of Culex Pipiens Pallens and substituted 2-chlorobenzoyl phenyl urea or thiourea. From QSAR study, some important structure factors influencing the larvicidal activity of this series are found. Electronic parameter is the most important factor influencing the lavicidal activity, and some compounds hare the same insecticidal activity as 2,6-difluorobenzoyl-4-chlorophenyl urea(PH6040).
1992, 9(4): 41-45
Abstract:
1H and 13C NMR techniques were used to study complexation of lanthanide ions with Gly-Ala in aqueous solution. For Yb complex with Gly-Ala the stability constant was calculated from the concentration dependence of lanthanide-induced shifts. 13C shifts induced by heavy lanthanide ions Dy3+, Ho3+, Er3+, Tm3+ and Yb3+ were analyzed by Reuben's method. The simulation for ligand conformation of lanthanide complex with Gly-Ala shows that the ligand segment C1-C2-N-C3 is in gauche form,while the segments C2-N-C3-C4 and C5-C2-N-C3 in trans form. The effects of side-group size of several glyeine-eontaining dipeptides on complex stability constants, ligand conformations and structure of complexes in solution were discussed.
1H and 13C NMR techniques were used to study complexation of lanthanide ions with Gly-Ala in aqueous solution. For Yb complex with Gly-Ala the stability constant was calculated from the concentration dependence of lanthanide-induced shifts. 13C shifts induced by heavy lanthanide ions Dy3+, Ho3+, Er3+, Tm3+ and Yb3+ were analyzed by Reuben's method. The simulation for ligand conformation of lanthanide complex with Gly-Ala shows that the ligand segment C1-C2-N-C3 is in gauche form,while the segments C2-N-C3-C4 and C5-C2-N-C3 in trans form. The effects of side-group size of several glyeine-eontaining dipeptides on complex stability constants, ligand conformations and structure of complexes in solution were discussed.
1992, 9(4): 46-51
Abstract:
The electromotive forces of the following cells 1. Ag|AgCl|HCl(mA)+NH4Cl(mB)+H2O|Glass-eleetrode2. Pt(black)|H2(latm)|HCl(mA)+NH4Cl(mB)+H2O|AgCl|Agg have been measured at total molalities of 0.1, 0.5, 1.0, 2.0 and 3.0 mol.kg-1 at 25℃. The potential of the glass-eteetrode was found not to be in agrtement with Nernst equation due to the effect from NH4+.The unsymmetrical potential of the glass-electrode have been derived:εG°=εG°'+(RT/F)ln[1+Kα(1+βyB)yB/(1-yB)] where yB is malar fraction of NH4Cl,εG°' is unsymmetrical potential of glass-electrode at yB=0. K is an equilibrium constant for ion-exchange, α and β are experimental parameters.
The electromotive forces of the following cells 1. Ag|AgCl|HCl(mA)+NH4Cl(mB)+H2O|Glass-eleetrode2. Pt(black)|H2(latm)|HCl(mA)+NH4Cl(mB)+H2O|AgCl|Agg have been measured at total molalities of 0.1, 0.5, 1.0, 2.0 and 3.0 mol.kg-1 at 25℃. The potential of the glass-eteetrode was found not to be in agrtement with Nernst equation due to the effect from NH4+.The unsymmetrical potential of the glass-electrode have been derived:εG°=εG°'+(RT/F)ln[1+Kα(1+βyB)yB/(1-yB)] where yB is malar fraction of NH4Cl,εG°' is unsymmetrical potential of glass-electrode at yB=0. K is an equilibrium constant for ion-exchange, α and β are experimental parameters.
1992, 9(4): 52-57
Abstract:
This paper reports the syntheses and properties of the coordination compounds of CoCl2 with dibenzo-24-crown-8, dibcnzo-30-crown-10, 4'-iodobcnzo-15-crown-5 and 4'-bromobenzo-15-crown and the coordination compounds of Co(NO3)2 with benzo-15-crown-5,4'-iodobenzo-15-crown-5 and 4'-bromobcnzo-15-crown-5. The complexes have been characterized by elemental analysis, IR, UV, DTA-TG and X-ray powder diffraction analysis as well as the molar conductance measurements.
This paper reports the syntheses and properties of the coordination compounds of CoCl2 with dibenzo-24-crown-8, dibcnzo-30-crown-10, 4'-iodobcnzo-15-crown-5 and 4'-bromobenzo-15-crown and the coordination compounds of Co(NO3)2 with benzo-15-crown-5,4'-iodobenzo-15-crown-5 and 4'-bromobcnzo-15-crown-5. The complexes have been characterized by elemental analysis, IR, UV, DTA-TG and X-ray powder diffraction analysis as well as the molar conductance measurements.
1992, 9(4): 58-60
Abstract:
Nonpoisonous inorganic pigments have been prepared from natural clay minerals:dolomitie attapulgite, monlmorillonite, and attapulgite. Pigmental colour was measured on the basis of Munsell renotation system. The composition and the framework structure of the pigments have been studied using XRD, EDAX and XPS techniques. The results showed that the ehromophone of the yellow pigments may be ascribed to the sulphur atoms with oxidation number+4 in the framework of the pigments.
Nonpoisonous inorganic pigments have been prepared from natural clay minerals:dolomitie attapulgite, monlmorillonite, and attapulgite. Pigmental colour was measured on the basis of Munsell renotation system. The composition and the framework structure of the pigments have been studied using XRD, EDAX and XPS techniques. The results showed that the ehromophone of the yellow pigments may be ascribed to the sulphur atoms with oxidation number+4 in the framework of the pigments.
1992, 9(4): 61-63
Abstract:
The molecular sieves SAPO-5 have been synthesized by hydrothermal crystallization from Pr3N-P2O5-Al2O3-SiO2-H2O-HF.Experiments of preparation conditions show that the key for the successful preparation of SAPO-5 lies in the formation of AlPO4 gel.The 27Al NMR results showed that in this case Al is four-coordinated.Tripropylamine was used as a template to stabilize tetrahedral Al and prevent it from attack of water.The EPMA analysis showed that an isomorphic substitution of P and A for Si occurs in SAPO-5 crystals.
The molecular sieves SAPO-5 have been synthesized by hydrothermal crystallization from Pr3N-P2O5-Al2O3-SiO2-H2O-HF.Experiments of preparation conditions show that the key for the successful preparation of SAPO-5 lies in the formation of AlPO4 gel.The 27Al NMR results showed that in this case Al is four-coordinated.Tripropylamine was used as a template to stabilize tetrahedral Al and prevent it from attack of water.The EPMA analysis showed that an isomorphic substitution of P and A for Si occurs in SAPO-5 crystals.
1992, 9(4): 64-66
Abstract:
Eight sulfonylurea compounds were synthesized and,oharacterized by IR, 1H NMR, MS spectroscopy and elemental analysis. It is found that the herbicidal activity of the compound 3d was as good as chlorsulfuron.
Eight sulfonylurea compounds were synthesized and,oharacterized by IR, 1H NMR, MS spectroscopy and elemental analysis. It is found that the herbicidal activity of the compound 3d was as good as chlorsulfuron.
1992, 9(4): 67-70
Abstract:
The excitation and emission spectra of LnBO3:Dy3+(Ln=La,Gd,Yb,Lu,Y,Sc) crystal powders were measured at room temperature.The dependence of the relative intensities of the 4F9/2→6H(15/2),13/2) fluorescent transitions of the Dy3+ ion in the LnBO3:Dy3+ host lattice on the chemical composition,crystal structure of the phesphors,and the concentrations of Dy3+ has been discussed.
The excitation and emission spectra of LnBO3:Dy3+(Ln=La,Gd,Yb,Lu,Y,Sc) crystal powders were measured at room temperature.The dependence of the relative intensities of the 4F9/2→6H(15/2),13/2) fluorescent transitions of the Dy3+ ion in the LnBO3:Dy3+ host lattice on the chemical composition,crystal structure of the phesphors,and the concentrations of Dy3+ has been discussed.
1992, 9(4): 71-74
Abstract:
A mixture of sulfuric, hydrochloric, and nitric acids are commonly used in chemical polishing of copper/brass articles as a pretreatment medium. The surface of the articles welded with silver solder has been investigated by using XPS, EDXM, XRD and TEM techniques, The results showed that the blackening of the surface of the seam is due to the precipitant sence of Ag2SO4, Ag2O, and silver particles on it.
A mixture of sulfuric, hydrochloric, and nitric acids are commonly used in chemical polishing of copper/brass articles as a pretreatment medium. The surface of the articles welded with silver solder has been investigated by using XPS, EDXM, XRD and TEM techniques, The results showed that the blackening of the surface of the seam is due to the precipitant sence of Ag2SO4, Ag2O, and silver particles on it.
1992, 9(4): 75-77
Abstract:
LB films of copper tetrakis(2,4-di-tert-pentyl phenoxy) phthalocyanine have been fabricated. Polarized UV-Vis spectral methed was used to identify the molecular association of the compound in chloroform solution as well as in the films.It is suggested that the macro cycles of the molecule have a parallel orientation in relation to the substrate.
LB films of copper tetrakis(2,4-di-tert-pentyl phenoxy) phthalocyanine have been fabricated. Polarized UV-Vis spectral methed was used to identify the molecular association of the compound in chloroform solution as well as in the films.It is suggested that the macro cycles of the molecule have a parallel orientation in relation to the substrate.
1992, 9(4): 78-80
Abstract:
Five complexes of 1,10-phenanthroline with rare earth trifluoroacetate were prepared from water-organic solvents. The complexes have been characterized by elemental analysis, infrared spectra, UV spectra, conductivity measurements, X-ray powder patterns and thermal analysis and are found to have following constitution:Ln(CF3COO)3(Phen)4·nH2O(Ln=La、Pr, Nd, Sm, Er)., Five complexes of 1,10-phenanthroline with rare earth trifluoroacetate were prepared from water-organic solvents. The complexes have been characterized by elemental analysis, infrared spectra, UV spectra, conductivity measurements, X-ray powder patterns and thermal analysis and are found to have following constitution:Ln(CF3COO)3(Phen)4·nH2O(Ln=La、Pr, Nd, Sm, Er).
Five complexes of 1,10-phenanthroline with rare earth trifluoroacetate were prepared from water-organic solvents. The complexes have been characterized by elemental analysis, infrared spectra, UV spectra, conductivity measurements, X-ray powder patterns and thermal analysis and are found to have following constitution:Ln(CF3COO)3(Phen)4·nH2O(Ln=La、Pr, Nd, Sm, Er)., Five complexes of 1,10-phenanthroline with rare earth trifluoroacetate were prepared from water-organic solvents. The complexes have been characterized by elemental analysis, infrared spectra, UV spectra, conductivity measurements, X-ray powder patterns and thermal analysis and are found to have following constitution:Ln(CF3COO)3(Phen)4·nH2O(Ln=La、Pr, Nd, Sm, Er).
1992, 9(4): 81-82
Abstract:
Pseudoionone has been synthesized from citral and acetone using sodium hydroxide or barium hydroxide as catalyst with yield of 86%.
Pseudoionone has been synthesized from citral and acetone using sodium hydroxide or barium hydroxide as catalyst with yield of 86%.
1992, 9(4): 83-86
Abstract:
Some N-alkyl, 5'-methoxycarbonyl and 8'-bromo derivatives of spiro[indoline-2,3'-3H-naphth[2,1-b] [1,4]oxazines] were synthesized by reacting corresponding substituted nitrosoonaphthols with Fischer base in anhydrous ethanol. Their structures were identified by elemental analysis and spectral methods. The photochromic behavior of the spirooxazines in toluene solution and polymer film were also examined.
Some N-alkyl, 5'-methoxycarbonyl and 8'-bromo derivatives of spiro[indoline-2,3'-3H-naphth[2,1-b] [1,4]oxazines] were synthesized by reacting corresponding substituted nitrosoonaphthols with Fischer base in anhydrous ethanol. Their structures were identified by elemental analysis and spectral methods. The photochromic behavior of the spirooxazines in toluene solution and polymer film were also examined.
1992, 9(4): 87-90
Abstract:
Gas permeabilities and permselectivities for gas pairs H2/N2 and O2/N2 through a series of aromatic polyimide membranes, which were prepared from four different dianhydrides (e. g. BPDA, BTDA, TDPA, and DSDA) and two kinds of diamines (e. g. ODA and MDA), have been investigated. Systematic variations in chemical structure were found to lead to significant changes in permeability and permselectivity. The polyimide membranes based on BPDA with low permeability have the highest H2/N2 and O2/N2 separation factors. The polyimide membranes based on DSDA have simultaneously higher permeability and higher permselectivity.
Gas permeabilities and permselectivities for gas pairs H2/N2 and O2/N2 through a series of aromatic polyimide membranes, which were prepared from four different dianhydrides (e. g. BPDA, BTDA, TDPA, and DSDA) and two kinds of diamines (e. g. ODA and MDA), have been investigated. Systematic variations in chemical structure were found to lead to significant changes in permeability and permselectivity. The polyimide membranes based on BPDA with low permeability have the highest H2/N2 and O2/N2 separation factors. The polyimide membranes based on DSDA have simultaneously higher permeability and higher permselectivity.
1992, 9(4): 91-94
Abstract:
The isothermal solubilities of ternary systems HCl-MgCl2-H2O and LiCl-MgCl2-H2O at -10℃ have been determined. Three crystallization fields corresponding to MgCl2·8H2O, MgCl2·6H2O and HCl·MgCl2·7H2O and three crystallization fields corresponding to MgCl2·8H2O,MgCl2·6H2O and LiCl·2H2O have been found for the first and second systems respectively.The existence of LiCl·MgCl2·7H2O and so called "2nd double salt" reported in[1] hasn't been found in this work.The salt-out rates of HCl and LiCl to MgCl2 were compared.
The isothermal solubilities of ternary systems HCl-MgCl2-H2O and LiCl-MgCl2-H2O at -10℃ have been determined. Three crystallization fields corresponding to MgCl2·8H2O, MgCl2·6H2O and HCl·MgCl2·7H2O and three crystallization fields corresponding to MgCl2·8H2O,MgCl2·6H2O and LiCl·2H2O have been found for the first and second systems respectively.The existence of LiCl·MgCl2·7H2O and so called "2nd double salt" reported in[1] hasn't been found in this work.The salt-out rates of HCl and LiCl to MgCl2 were compared.
1992, 9(4): 95-97
Abstract:
Two types of Co-Mo spherical sulfur-resistant water-gas shift catalysts, B302Q and EB-4, have been studied in their microstructure by XRF, XRD and XPS methods.The results showed that the fcrmation of CoAl2O4 and CoMoO4 phases during the calcination leads in the deactivation of the catalyst B302Q.
Two types of Co-Mo spherical sulfur-resistant water-gas shift catalysts, B302Q and EB-4, have been studied in their microstructure by XRF, XRD and XPS methods.The results showed that the fcrmation of CoAl2O4 and CoMoO4 phases during the calcination leads in the deactivation of the catalyst B302Q.
1992, 9(4): 98-101
Abstract:
The title compounds (Ln=Pr, Nd, n=2; Ln=Gd, n=1) were prepared by reacting LnCl3 with NaC5H5 and K2C8H8. The single crystals of (η5-C5H5)Pr(η8-C8H8)(THF)2 obtained at -15℃ in THF have monoclinic space group P21 and a=0.8427(2)nm, b=0.9835 (2)nm, c=1.1799(2)nm, β=102.82(2)°, v=0.9536nm3, and Z=2. The final R value is 0.0383. The centroids of the C5H5 ring, C8H8 ring,and the two oxygen atoms from the two THF molecules form a distorted tetrahedron.
The title compounds (Ln=Pr, Nd, n=2; Ln=Gd, n=1) were prepared by reacting LnCl3 with NaC5H5 and K2C8H8. The single crystals of (η5-C5H5)Pr(η8-C8H8)(THF)2 obtained at -15℃ in THF have monoclinic space group P21 and a=0.8427(2)nm, b=0.9835 (2)nm, c=1.1799(2)nm, β=102.82(2)°, v=0.9536nm3, and Z=2. The final R value is 0.0383. The centroids of the C5H5 ring, C8H8 ring,and the two oxygen atoms from the two THF molecules form a distorted tetrahedron.
1992, 9(4): 102-106
Abstract:
By reaeting substituted heteroeyele tellttronium salts with aldehydes under mild conditions ccrresponding chalcones and alkadienones were obtained. In the presence of dibutyl telluride, 2-bromomethyl-5-nitrofuran condensed easily with aldehydes in THF to afford corresponding olefin derivatives in one-pot reaction.
By reaeting substituted heteroeyele tellttronium salts with aldehydes under mild conditions ccrresponding chalcones and alkadienones were obtained. In the presence of dibutyl telluride, 2-bromomethyl-5-nitrofuran condensed easily with aldehydes in THF to afford corresponding olefin derivatives in one-pot reaction.
1992, 9(4): 107-110
Abstract:
The effects of thermal treatment on Cu-O/Al2O3, Fe-O/Al2O3, Cu-Fe-O/Al2O3 and La-Cu-Fe-O/Al2O3 at 750~1050℃ are studied. The changes in BET surface, average particle size in relation to the interaction between Al2O3 and active components are elucidated. It is found that both phase transition of γ-Al2O3 to α-Al2O3 and sintering of active components cccurred on two samples containing ferric oxides at 850℃. Such a phase transition occurred only until 950℃ for Cu-O/Al2O3. The effects on the reduction of phase transition temperature of γ-Al2O3 follow Cu-Fe > Fe > Cu. La2O3 raises phase transition temperature of γ-Al2O3 to α-Al2O3 and resistence sintering of active components. As detected by XRD the thermal stable LaAlO3 is formed at 850℃. LaAlO3 may highly disperse into the active components retarding migration and agglomeration of active components at high temperature.
The effects of thermal treatment on Cu-O/Al2O3, Fe-O/Al2O3, Cu-Fe-O/Al2O3 and La-Cu-Fe-O/Al2O3 at 750~1050℃ are studied. The changes in BET surface, average particle size in relation to the interaction between Al2O3 and active components are elucidated. It is found that both phase transition of γ-Al2O3 to α-Al2O3 and sintering of active components cccurred on two samples containing ferric oxides at 850℃. Such a phase transition occurred only until 950℃ for Cu-O/Al2O3. The effects on the reduction of phase transition temperature of γ-Al2O3 follow Cu-Fe > Fe > Cu. La2O3 raises phase transition temperature of γ-Al2O3 to α-Al2O3 and resistence sintering of active components. As detected by XRD the thermal stable LaAlO3 is formed at 850℃. LaAlO3 may highly disperse into the active components retarding migration and agglomeration of active components at high temperature.
1992, 9(4): 111-113
Abstract:
The effect of rare earth on composition and structure of copper oxidizing film has been studied by using thermal analysis, XPS and SEM. Results showed that rare earth is able to obviously improve the protecting ability and inhance the anti-oxidation property of copper amples.
The effect of rare earth on composition and structure of copper oxidizing film has been studied by using thermal analysis, XPS and SEM. Results showed that rare earth is able to obviously improve the protecting ability and inhance the anti-oxidation property of copper amples.
1992, 9(4): 114-116
Abstract:
The activation time of transpassive film formed on 304 stainless steel in the transpassivation region is almost 2 magnitude of order higher than that of passive film formed in passivation region and its breakdown potential is strikingly improved if post-treatment is conducted in a McO42- containing solution.It is believed that the enhancement of stability of surface film by transpassivation and post-treatment is ascribed to increase of film thickness,higher ratio of Fe3+/Fe2+ and the adsorption of molybdenum into film.
The activation time of transpassive film formed on 304 stainless steel in the transpassivation region is almost 2 magnitude of order higher than that of passive film formed in passivation region and its breakdown potential is strikingly improved if post-treatment is conducted in a McO42- containing solution.It is believed that the enhancement of stability of surface film by transpassivation and post-treatment is ascribed to increase of film thickness,higher ratio of Fe3+/Fe2+ and the adsorption of molybdenum into film.
1992, 9(4): 117-119
Abstract:
Optically active camphor(3) was synthesized in rational yield via dehydrogenation of n-borneol (2a) which was a natural product or obtained via hydration of 2-pinene(1) by one step. The dehydrogenation was carried out in the presence of Zn-laden catalyst, in gasphase,without use of any solvents. The camphor obtained possesses almost the same optical pureness as its starting material-natural n-borneol or 2-pinene.
Optically active camphor(3) was synthesized in rational yield via dehydrogenation of n-borneol (2a) which was a natural product or obtained via hydration of 2-pinene(1) by one step. The dehydrogenation was carried out in the presence of Zn-laden catalyst, in gasphase,without use of any solvents. The camphor obtained possesses almost the same optical pureness as its starting material-natural n-borneol or 2-pinene.
1992, 9(4): 120-122
Abstract:
An asymmetric tetrathiafulvalene detivative has been preparped. The structure of the compound has been confirmed by IR,1H NMR.MS and elemental analysis.
An asymmetric tetrathiafulvalene detivative has been preparped. The structure of the compound has been confirmed by IR,1H NMR.MS and elemental analysis.
