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1989 Volume 6 Issue 1
1989, 6(1): 1-8
Abstract:
In this paper,the present status of the advances in the study of polymer solid electrolytes particularly based on the polyethylene, oxide, the achievements so far reached, the problems remained to be solved and the prospects of this kind of electrolyte are discussed.
In this paper,the present status of the advances in the study of polymer solid electrolytes particularly based on the polyethylene, oxide, the achievements so far reached, the problems remained to be solved and the prospects of this kind of electrolyte are discussed.
1989, 6(1): 9-12
Abstract:
Graft copolymerization of AN onto cassava starch gelatinized by alkali at room temperature has been studied using KMnO4 as initiator in acid solution. Result showed high monomer convertion to polymer (80%), very high graft efficiency (95%), and high molecular weight of graft polymer (3×105). The hyorolyzate of graft copolymer can absorb up to over 2000 times of water (g/g).
Graft copolymerization of AN onto cassava starch gelatinized by alkali at room temperature has been studied using KMnO4 as initiator in acid solution. Result showed high monomer convertion to polymer (80%), very high graft efficiency (95%), and high molecular weight of graft polymer (3×105). The hyorolyzate of graft copolymer can absorb up to over 2000 times of water (g/g).
1989, 6(1): 13-16
Abstract:
In this paper the synthesis and chelating property of a macroporous chelate resin,poly-N-salicylidene vinylaniline (PSVA) are studied. It is found that the resin has a good adsorbability for Cu2+ at pH=5 and for Fe3+ in 0.17 mol/L HCl. The adsorption capacity was 1.35 mmol Cu2+ per g PSVA. A satisfactory result was obtained, using PSVA resin in removing trace amount of Cu2+ from nickel electroplating solution and wasted water. The resin can be regenerated by successively washing with mixture of 5%EDTA and 1.5mol/L H2SO4.
In this paper the synthesis and chelating property of a macroporous chelate resin,poly-N-salicylidene vinylaniline (PSVA) are studied. It is found that the resin has a good adsorbability for Cu2+ at pH=5 and for Fe3+ in 0.17 mol/L HCl. The adsorption capacity was 1.35 mmol Cu2+ per g PSVA. A satisfactory result was obtained, using PSVA resin in removing trace amount of Cu2+ from nickel electroplating solution and wasted water. The resin can be regenerated by successively washing with mixture of 5%EDTA and 1.5mol/L H2SO4.
1989, 6(1): 17-21
Abstract:
AB crosslinked polymers (ABCP) were synthesized from low molecular weight vinyl-terminated polyurethane prepolymers and vinyl monomers such as styrene,methyl methacrylate, vinyl acetate, etc. ABCPs displayed a two-phased morphology with plastic components forming the continuous phase and PU-rich domains forming separation phase on the electron micrographs. The irregular shapes and a highly polydisperse distribution of PU-rich domain size were observed. These morphological features of ABCPs were quite different from linear AB and ABA block copolymers owing to the crosslinking between compoments A and B in ABCPs.The crosslinking density of ABCPs ahd molecular weight of prepolymers showed a notable effect on the compatibility of two components and the mopho1ogy of ABCPs as well.
AB crosslinked polymers (ABCP) were synthesized from low molecular weight vinyl-terminated polyurethane prepolymers and vinyl monomers such as styrene,methyl methacrylate, vinyl acetate, etc. ABCPs displayed a two-phased morphology with plastic components forming the continuous phase and PU-rich domains forming separation phase on the electron micrographs. The irregular shapes and a highly polydisperse distribution of PU-rich domain size were observed. These morphological features of ABCPs were quite different from linear AB and ABA block copolymers owing to the crosslinking between compoments A and B in ABCPs.The crosslinking density of ABCPs ahd molecular weight of prepolymers showed a notable effect on the compatibility of two components and the mopho1ogy of ABCPs as well.
1989, 6(1): 22-25
Abstract:
The effects of the catalyst system and composition of ethylene-propylene copolymers on the crystallization rates of the copolymer have been studied by dilatometry. It is shown that for the same catalyst system, the maximum crystallisation rate 1/t(1/2)(max) of the copolymer increased with the increase of the ethylene content in it.The maximum crystallization rates of ethylene-propylene copolymers obtained with various catalyst systems were found in the following order:(VOCl3-) >(V5-0) >(V(acac)3-) The order of 1/t1/2(max) for the catalyst system with addition of an active agent ETCA was:(VOCl3-ETCA) >(V5-9-ETCA) >(V(acac)3-ETCA) The results of the crystallinity and glass transition temperature of the coplymers, as well as the composition of copolymers of differnt sequence suggested that the ethylene-propylene copolymer obtained with VOCl3- had longer PE species and those obtained with V5-9- had shorter PE species. More irregular structure was formed when the copolymer is obtained with V(acac)3-catalyst system.
The effects of the catalyst system and composition of ethylene-propylene copolymers on the crystallization rates of the copolymer have been studied by dilatometry. It is shown that for the same catalyst system, the maximum crystallisation rate 1/t(1/2)(max) of the copolymer increased with the increase of the ethylene content in it.The maximum crystallization rates of ethylene-propylene copolymers obtained with various catalyst systems were found in the following order:(VOCl3-) >(V5-0) >(V(acac)3-) The order of 1/t1/2(max) for the catalyst system with addition of an active agent ETCA was:(VOCl3-ETCA) >(V5-9-ETCA) >(V(acac)3-ETCA) The results of the crystallinity and glass transition temperature of the coplymers, as well as the composition of copolymers of differnt sequence suggested that the ethylene-propylene copolymer obtained with VOCl3- had longer PE species and those obtained with V5-9- had shorter PE species. More irregular structure was formed when the copolymer is obtained with V(acac)3-catalyst system.
1989, 6(1): 26-29
Abstract:
Two novel chiral diphosphines, 1, 6 -bis(diphenyl-phosphino)-2, 3, 4, 5- dibenzylidene-D-mannitol and 1, 6-bis-(diphenylphosphino)-3, 4-benzylidene- 2, 5-methylene-D-mannitol have been synthesized from D-mannitol. The Rh(I) complexes of both chiral ligands have been used as catalysts in the asymmetic hydrogenation of α-acetamidocinnamic acid, but no enantioselectivity was observed in both cases, furthermore, no hydrogenation activity was Shown in the reaction in the presence of the former ligand.A preliminary explanation of the results observed in asymmetrie hydrogenation is suggested in the paper.
Two novel chiral diphosphines, 1, 6 -bis(diphenyl-phosphino)-2, 3, 4, 5- dibenzylidene-D-mannitol and 1, 6-bis-(diphenylphosphino)-3, 4-benzylidene- 2, 5-methylene-D-mannitol have been synthesized from D-mannitol. The Rh(I) complexes of both chiral ligands have been used as catalysts in the asymmetic hydrogenation of α-acetamidocinnamic acid, but no enantioselectivity was observed in both cases, furthermore, no hydrogenation activity was Shown in the reaction in the presence of the former ligand.A preliminary explanation of the results observed in asymmetrie hydrogenation is suggested in the paper.
1989, 6(1): 30-35
Abstract:
Three cardo bisphenols (phenolphalan, phenolphthalimidine and N-methyl-phenolphtha-limidinr) were used to synthesize new polyaryl ether sulfones. The effect of the structures of various cardo groups on the polycondensation was investigated to provide further experimental evidence for mechanistic study. The results show that all these cardo bisphenols have a polycondensation behavior similar to phenolphthalein, i.e. the rates of polymer formation are much greater than those of polymers from common bisphenols, such as Bisphenol-A or Bisphenol-S. The structures of these cardo polymers Were characterized by IRand 13C NMR methods.
Three cardo bisphenols (phenolphalan, phenolphthalimidine and N-methyl-phenolphtha-limidinr) were used to synthesize new polyaryl ether sulfones. The effect of the structures of various cardo groups on the polycondensation was investigated to provide further experimental evidence for mechanistic study. The results show that all these cardo bisphenols have a polycondensation behavior similar to phenolphthalein, i.e. the rates of polymer formation are much greater than those of polymers from common bisphenols, such as Bisphenol-A or Bisphenol-S. The structures of these cardo polymers Were characterized by IRand 13C NMR methods.
1989, 6(1): 36-40
Abstract:
Graft copolymerization of styrene. (St) onto humic acid (HA), using H2O2-FeCl2 redox system as initiator in DMOSmedium was investigated.It was found that HA had distinct inhibiting and retarding effect on the polymerization of St,and the ratio of H2O2-FeCl2 was an important factor influencing the graft copolymerization.With increase of the H2O2-FeCl2 ratio,the rate of polymerization increased,while the grafting cfficiency decreased, the grafting degree approched a maximal value when the H2O2-FeCl2 ratio was 3(mol/mol).The grafting efficiency and grafting degree increased with increase of polymerization temperature The ratio of St to HA also had a direct influence on the grafting efficiency and grafting degree but not on the grafting ratio. The appearance of a new adsorption band (1120cm-1) in the IR spectrum of copolymer was attributed to C-O-C link formed in the HA-g-PSt molecule during the polymerization. The product obtained by further sulfonation of graft copolymer is readily Soluble in water, acid and alkalisolution.
Graft copolymerization of styrene. (St) onto humic acid (HA), using H2O2-FeCl2 redox system as initiator in DMOSmedium was investigated.It was found that HA had distinct inhibiting and retarding effect on the polymerization of St,and the ratio of H2O2-FeCl2 was an important factor influencing the graft copolymerization.With increase of the H2O2-FeCl2 ratio,the rate of polymerization increased,while the grafting cfficiency decreased, the grafting degree approched a maximal value when the H2O2-FeCl2 ratio was 3(mol/mol).The grafting efficiency and grafting degree increased with increase of polymerization temperature The ratio of St to HA also had a direct influence on the grafting efficiency and grafting degree but not on the grafting ratio. The appearance of a new adsorption band (1120cm-1) in the IR spectrum of copolymer was attributed to C-O-C link formed in the HA-g-PSt molecule during the polymerization. The product obtained by further sulfonation of graft copolymer is readily Soluble in water, acid and alkalisolution.
1989, 6(1): 41-45
Abstract:
The solid complexes of La, Ce,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho, Er,Tm, Yb, Lu, and Y with 2-ethylhexyl phosphonic acid mono(2-ethylhexyl)ester were prepared.FTIR spectra of these complexes have been studied and the principal infrared absorption bands have been assigned for region 4000-100cm-1.The 150cm-1 is believed to be Ln-O stretching vibration band, and the band near 250cm-1 is the coupling band of COPO, CCPO skeleton torsion vibration with Ln-O bond. The experimental result showed that Ln-O bonds in these rare earth complexes are principally ionic.,The FO2 coordination with rare carth is in bridging form. A Volymeric model of the complexes is proposed(Fig. la)
The solid complexes of La, Ce,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho, Er,Tm, Yb, Lu, and Y with 2-ethylhexyl phosphonic acid mono(2-ethylhexyl)ester were prepared.FTIR spectra of these complexes have been studied and the principal infrared absorption bands have been assigned for region 4000-100cm-1.The 150cm-1 is believed to be Ln-O stretching vibration band, and the band near 250cm-1 is the coupling band of COPO, CCPO skeleton torsion vibration with Ln-O bond. The experimental result showed that Ln-O bonds in these rare earth complexes are principally ionic.,The FO2 coordination with rare carth is in bridging form. A Volymeric model of the complexes is proposed(Fig. la)
1989, 6(1): 46-49
Abstract:
Ionic conductivity behavior of complexes obtained from high molecular weight polyoxyethylene (PEO) and NaCNS or KCNS has been studied.The results showed that the complexes at EO/metal ratio>4 exhibited a knee in the Arrhenius plot of conductivity vs temperature. At EO/NaCNS=20, conductivity at 25℃ approached 2.8×10-6Ω-1cm-1, which is higher than those at EO/NaCNS=4 or 50. For complexes of PEO with KCNS the conduetivity at 25℃ reached 2×10-5Ω-1cm-1 at EO/KCNS=20, while at EO/KCNS=4 the conductivity obeyed the Arrhenius equation at the temperature ranging from 20 to 90℃. Addition of γ-butyrolactone evidently increases the conductivity of the complex.
Ionic conductivity behavior of complexes obtained from high molecular weight polyoxyethylene (PEO) and NaCNS or KCNS has been studied.The results showed that the complexes at EO/metal ratio>4 exhibited a knee in the Arrhenius plot of conductivity vs temperature. At EO/NaCNS=20, conductivity at 25℃ approached 2.8×10-6Ω-1cm-1, which is higher than those at EO/NaCNS=4 or 50. For complexes of PEO with KCNS the conduetivity at 25℃ reached 2×10-5Ω-1cm-1 at EO/KCNS=20, while at EO/KCNS=4 the conductivity obeyed the Arrhenius equation at the temperature ranging from 20 to 90℃. Addition of γ-butyrolactone evidently increases the conductivity of the complex.
1989, 6(1): 50-52
Abstract:
The dipyridine (dipy) complexes of rare earth(Ⅲ)B20H18 were prepared throughfollowing reactions: 3H2B20H18+Ln2O3→Ln2(B20H18)3+3H2O, Ln2(B20H18)3+8dipy
[Ln(dipy)4]2(B20H18)3 where Ln=Yb, Tm, Ho, Gd and Sm.All the compounds obtained are solid and soluble in polar solvents, but not in nonpolar solvents. They are stable to air and moisture.The complexes were identified by elemental analysis, electroconductivity, IR spectra and TG-DTA measurements. Dipy is found to be Londed to the rare earth via N atom.The molar conductance data indicate that these complexes are ionic and behave as 2:3 electrolytes in DMF.
The dipyridine (dipy) complexes of rare earth(Ⅲ)B20H18 were prepared throughfollowing reactions: 3H2B20H18+Ln2O3→Ln2(B20H18)3+3H2O, Ln2(B20H18)3+8dipy
[Ln(dipy)4]2(B20H18)3 where Ln=Yb, Tm, Ho, Gd and Sm.All the compounds obtained are solid and soluble in polar solvents, but not in nonpolar solvents. They are stable to air and moisture.The complexes were identified by elemental analysis, electroconductivity, IR spectra and TG-DTA measurements. Dipy is found to be Londed to the rare earth via N atom.The molar conductance data indicate that these complexes are ionic and behave as 2:3 electrolytes in DMF.
1989, 6(1): 53-56
Abstract:
Seven indolium derivatives have been.prebared by condensation of 1, 2, 3, 3-tetramethylindolium iodide with 5-substituted pheny1-2-furaldehydes in the presenee of piperidine.The synthetic method and spectral properties of the iodides are reported.
Seven indolium derivatives have been.prebared by condensation of 1, 2, 3, 3-tetramethylindolium iodide with 5-substituted pheny1-2-furaldehydes in the presenee of piperidine.The synthetic method and spectral properties of the iodides are reported.
1989, 6(1): 57-59
Abstract:
The synthesis and properties of two comb polyethers are reported. Ethylene glycol monoethyl ether glycidyl ether or diethylene glycol monoethyl ether glycidyl ether were polymerized in the presence of (i-Bu)3Al catalyst system, giving corresponding comb polyethers. They showed good complexing capacities for K+, Na+ and PTC activities for the nucleophilic substitution of BuBr by PhOK.
The synthesis and properties of two comb polyethers are reported. Ethylene glycol monoethyl ether glycidyl ether or diethylene glycol monoethyl ether glycidyl ether were polymerized in the presence of (i-Bu)3Al catalyst system, giving corresponding comb polyethers. They showed good complexing capacities for K+, Na+ and PTC activities for the nucleophilic substitution of BuBr by PhOK.
1989, 6(1): 60-62
Abstract:
The trimethylsilylcyelopentadienyl lanthanide dichlorides Cp'LnCl2·nTHF (Cp'=trime-thylsilylcyclopentadienyl; Ln=Nd, Sm, Gd; n=0, 1, 2) were synthesized and characterized by elemental analyses, infrared spectra, nuclear magnetic resonance and thermal gravimetry techniques.During the synthesis the dimer of trimethylsilylcyclopentadiene was appeared in the solution.
The trimethylsilylcyelopentadienyl lanthanide dichlorides Cp'LnCl2·nTHF (Cp'=trime-thylsilylcyclopentadienyl; Ln=Nd, Sm, Gd; n=0, 1, 2) were synthesized and characterized by elemental analyses, infrared spectra, nuclear magnetic resonance and thermal gravimetry techniques.During the synthesis the dimer of trimethylsilylcyclopentadiene was appeared in the solution.
1989, 6(1): 63-65
Abstract:
This study deals with properties and thermal reactions of Co3[Fe(CN)6]2 supported on silica, γ-alumina and magnesia. The final solid products of thermal decomposition in hydrogen atmosphere consisted of Co-Fe alloy and highly dispersed surface Fe(Ⅱ)ions.HCN was formed on silica and γ-alumina as a result of (CN)2 hydrogenation. Neither HCN nor NH3 was produced on magnesia because of the basicity of the support. Thus HCN may be considered as an intermediate of the hydrogenation process from(CN)2 to NH3.
This study deals with properties and thermal reactions of Co3[Fe(CN)6]2 supported on silica, γ-alumina and magnesia. The final solid products of thermal decomposition in hydrogen atmosphere consisted of Co-Fe alloy and highly dispersed surface Fe(Ⅱ)ions.HCN was formed on silica and γ-alumina as a result of (CN)2 hydrogenation. Neither HCN nor NH3 was produced on magnesia because of the basicity of the support. Thus HCN may be considered as an intermediate of the hydrogenation process from(CN)2 to NH3.
1989, 6(1): 66-68
Abstract:
The equilibrium constant of the isotopic exchange reaction: C16O16O(g)+H217O(l)=C16O17O(g)+H216O(l) at 25℃ has been determined for the first time to be K17=1.0190±0.0007(σ).
The equilibrium constant of the isotopic exchange reaction: C16O16O(g)+H217O(l)=C16O17O(g)+H216O(l) at 25℃ has been determined for the first time to be K17=1.0190±0.0007(σ).
1989, 6(1): 69-71
Abstract:
The electrochemical epoxidation of cyclohexene has been invest gated on Pt anode in H2O-NaBr-MsCN medium using a rotating disk electrode and a rotating ring-disk electrode.The electrolytic products were identified by means of IR and MS. The results show that cyclohexene was oxidized into epoxycyclohexane by an EC catalytic mechanism: Br-1+H2O→HBrO+H++2e↕HBrO+Cyclohexene
Br-1+O
+H+ The calculated rate constant k1 of the second reaction was (2.1±0.4)×10-2·s-1.
The electrochemical epoxidation of cyclohexene has been invest gated on Pt anode in H2O-NaBr-MsCN medium using a rotating disk electrode and a rotating ring-disk electrode.The electrolytic products were identified by means of IR and MS. The results show that cyclohexene was oxidized into epoxycyclohexane by an EC catalytic mechanism: Br-1+H2O→HBrO+H++2e↕HBrO+Cyclohexene
Br-1+O+H+ The calculated rate constant k1 of the second reaction was (2.1±0.4)×10-2·s-1.
1989, 6(1): 72-74
Abstract:
Using dry acetone as solvent, the solid complexes of lanthanides, yttrium and scandium nitrate with 15-crown-5 have been prepared. According to elemental analysis, the compositions of the complexes were found to be RE(NO3)3·15C5 for La-Eu and RE(NO3)3·15C5·3H2O for Gd-Lu, Y and Sc. Some of their. properties were determined by thermoanalysis, IR and XPS.
Using dry acetone as solvent, the solid complexes of lanthanides, yttrium and scandium nitrate with 15-crown-5 have been prepared. According to elemental analysis, the compositions of the complexes were found to be RE(NO3)3·15C5 for La-Eu and RE(NO3)3·15C5·3H2O for Gd-Lu, Y and Sc. Some of their. properties were determined by thermoanalysis, IR and XPS.
1989, 6(1): 75-78
Abstract:
A spectrophotometric method was used to study the interaction of an anionic dye ECAB with a nonionic surfactant Triton X-100. The binding constant of ECAB with the TX-100 micelles and the number of binding sites were calculated by a modified Sepulveda's method. The effect of an anionic surfactant SDS on the interaction between the ECAB and the TX-100 was also investigated.
A spectrophotometric method was used to study the interaction of an anionic dye ECAB with a nonionic surfactant Triton X-100. The binding constant of ECAB with the TX-100 micelles and the number of binding sites were calculated by a modified Sepulveda's method. The effect of an anionic surfactant SDS on the interaction between the ECAB and the TX-100 was also investigated.
1989, 6(1): 79-82
Abstract:
Polyacetylene/carbon fibre composite film has been synthesized by polymerizaiton of acetylene on carbon fibre treated with cold plasma tecbnique.Scanning electron micrographs showed that some graft-copolymer may be formed on the surface of the carbon fibre. The stability to air and the thermostability of the composite film were better than that of the pure polyacetylene film. The degree of oxidation, energy density, power density and short curtent of the cell consisted of composed polyacetylene film are also better than those of the cell composed of pure PA electrode.
Polyacetylene/carbon fibre composite film has been synthesized by polymerizaiton of acetylene on carbon fibre treated with cold plasma tecbnique.Scanning electron micrographs showed that some graft-copolymer may be formed on the surface of the carbon fibre. The stability to air and the thermostability of the composite film were better than that of the pure polyacetylene film. The degree of oxidation, energy density, power density and short curtent of the cell consisted of composed polyacetylene film are also better than those of the cell composed of pure PA electrode.
1989, 6(1): 83-84
Abstract:
Si-doped Nd-Fe-B-alloys (Nd15Fe77-xSixB8, x=4,8, 16, 18 at%) were prepared in a graphite furnace. X-ray diffraction and scanning electron micrographs of the products showed that besides Nd2Fe14B there were some Nd-rich phases when silicon had doped in at 8 at%.The Curie temperature(TC) was increased from 310℃ to 350℃ by do ping with 8-16 at% silicon. When Si content was greater than 16 at%, a new phase was formed and the TC of the alloy markedly decreased. The density of the alloy slightly deereases with increase of Si when Si content is over 4 at%. The hardness of the alloy has a maximum value at about 8 at% of Si.
Si-doped Nd-Fe-B-alloys (Nd15Fe77-xSixB8, x=4,8, 16, 18 at%) were prepared in a graphite furnace. X-ray diffraction and scanning electron micrographs of the products showed that besides Nd2Fe14B there were some Nd-rich phases when silicon had doped in at 8 at%.The Curie temperature(TC) was increased from 310℃ to 350℃ by do ping with 8-16 at% silicon. When Si content was greater than 16 at%, a new phase was formed and the TC of the alloy markedly decreased. The density of the alloy slightly deereases with increase of Si when Si content is over 4 at%. The hardness of the alloy has a maximum value at about 8 at% of Si.
1989, 6(1): 85-88
Abstract:
The effects of addition of rare earth metals on the electrochemical performance of Li-Al alloy as a negative electrode in secondary lithium battery were studied using cyclic voltammetry, charge-discharge operation and electrochemical impedance measurement.Li-Al and Li-Al-RE alloys were prepared respectively by underpotential deposition of Li on pure Al and Al-RE alloys in argon atmosphere and 1M LiClO4/propylene carbonate electrolyte at 25℃.The results showed that with addition of ca. 1.0% rare earth elements the anodic peak current in the voltammogram of Li-Al alloys increased in a few mA/cm2 for 99% Al matrix and in more than 10mA/cm2 for 99.9% Al matrix, and the charge-discharge efficiencies increased in 10% and 20%, respectively.The reaction resistance of Li-Al-RE alloy was smaller than that of Li-Al alloy.This beneficial effect is likely due to the nucleation action of the rare-earths as a foreign element in alloy, which changes the structure of Li-Al alloys and make the insertion and diffusion of Li into Al easier.
The effects of addition of rare earth metals on the electrochemical performance of Li-Al alloy as a negative electrode in secondary lithium battery were studied using cyclic voltammetry, charge-discharge operation and electrochemical impedance measurement.Li-Al and Li-Al-RE alloys were prepared respectively by underpotential deposition of Li on pure Al and Al-RE alloys in argon atmosphere and 1M LiClO4/propylene carbonate electrolyte at 25℃.The results showed that with addition of ca. 1.0% rare earth elements the anodic peak current in the voltammogram of Li-Al alloys increased in a few mA/cm2 for 99% Al matrix and in more than 10mA/cm2 for 99.9% Al matrix, and the charge-discharge efficiencies increased in 10% and 20%, respectively.The reaction resistance of Li-Al-RE alloy was smaller than that of Li-Al alloy.This beneficial effect is likely due to the nucleation action of the rare-earths as a foreign element in alloy, which changes the structure of Li-Al alloys and make the insertion and diffusion of Li into Al easier.
1989, 6(1): 89-90
Abstract:
XPS studies show that the valence of Ba in superconducting YBa2Cu3O)~7 is +2.The shoulders on the Ba 3d spectrum of the air exposed superconductor did not originate fromthe chemical shift, but from the different charging effect.
XPS studies show that the valence of Ba in superconducting YBa2Cu3O)~7 is +2.The shoulders on the Ba 3d spectrum of the air exposed superconductor did not originate fromthe chemical shift, but from the different charging effect.
1989, 6(1): 91-94
Abstract:
In this paper, the pyrolysis of some ABS resins was carried out by using thermogravimetry and the kinetic parameters concerned were obtained by two dimension linear correlation.The results were compared with those obtainod by integral and differential methods.It is also found that in main stage of pyrolysis of ABS resins the heating rate showed noobvious effect on the kinetic parameters.
In this paper, the pyrolysis of some ABS resins was carried out by using thermogravimetry and the kinetic parameters concerned were obtained by two dimension linear correlation.The results were compared with those obtainod by integral and differential methods.It is also found that in main stage of pyrolysis of ABS resins the heating rate showed noobvious effect on the kinetic parameters.
1989, 6(1): 95-96
Abstract:
Two technologies. of three-exit process with and without reflux for the simutaneous separation of a three-component system (Cu, Co, Ni) have been proposed. The separation was carried out through extraction with HEH(EHP). The three clements were obtained in following purity(%):by technology 1: Cu 99, Co 97, Ni 99.5by technology 2: Cu 99.9 Co 85, Ni 85
Two technologies. of three-exit process with and without reflux for the simutaneous separation of a three-component system (Cu, Co, Ni) have been proposed. The separation was carried out through extraction with HEH(EHP). The three clements were obtained in following purity(%):by technology 1: Cu 99, Co 97, Ni 99.5by technology 2: Cu 99.9 Co 85, Ni 85
