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2002 Volume 19 Issue 7
2002, 19(7): 613-616
Abstract:
The bone morphogenetic protein-2(rhBMP-2) was combined with polycyanoacrylate by improved emulsion polymerization method to give nanoparticles for injection use. Their biological activities were tested both in vivo and in vitro. The process of the recombination preparation was optimized by orthogonal factorization method. The size of the nanoparticle was determined by electronic microscopy. The content of rhBMP-2 and its encapsulation rate were determined by UV spectrophotometry. The proliferation of the cell was measured by MTT assay. The biological activity of the rhBMP-2 polycyanoacrylate nanoparticle was examined by alkaline phosphatase(ALP) coloration method. The results showed that the rhBMP-2 polycyanoacrylate nanoparticle was homogenous and stable with the average diameter (107±12) nm and rhBMP encapsulation rate of 78%. The in vivo experiment showed that 80% of rhBMP could be released in 10 days. The ALP level in the marrow stromal cell(MSC) cultural system increased significantly(P<0.01) by adding rhBMP nanoparticle to MSC system.
The bone morphogenetic protein-2(rhBMP-2) was combined with polycyanoacrylate by improved emulsion polymerization method to give nanoparticles for injection use. Their biological activities were tested both in vivo and in vitro. The process of the recombination preparation was optimized by orthogonal factorization method. The size of the nanoparticle was determined by electronic microscopy. The content of rhBMP-2 and its encapsulation rate were determined by UV spectrophotometry. The proliferation of the cell was measured by MTT assay. The biological activity of the rhBMP-2 polycyanoacrylate nanoparticle was examined by alkaline phosphatase(ALP) coloration method. The results showed that the rhBMP-2 polycyanoacrylate nanoparticle was homogenous and stable with the average diameter (107±12) nm and rhBMP encapsulation rate of 78%. The in vivo experiment showed that 80% of rhBMP could be released in 10 days. The ALP level in the marrow stromal cell(MSC) cultural system increased significantly(P<0.01) by adding rhBMP nanoparticle to MSC system.
2002, 19(7): 617-620
Abstract:
The salicylaldimnato Ni(Ⅱ) complexes activated with modified methylaluminoxane(MMAO) as catalysts were employed in addition polymerization of norbornene to give soluble polymer with hight molecular weight. The catalytic activity, polymer yield, and molecular weight of polymer product were found significantly depended on the reaction condifions, such as n(Al)/n(Ni) ratio, monomer concentration and polymerization reaction temperature and time. The catalyst activity of up to 1.3×107g/(mol·h), and viscosity-average molecular weight of polymer of up to 106 were obtained at optimum condition.
The salicylaldimnato Ni(Ⅱ) complexes activated with modified methylaluminoxane(MMAO) as catalysts were employed in addition polymerization of norbornene to give soluble polymer with hight molecular weight. The catalytic activity, polymer yield, and molecular weight of polymer product were found significantly depended on the reaction condifions, such as n(Al)/n(Ni) ratio, monomer concentration and polymerization reaction temperature and time. The catalyst activity of up to 1.3×107g/(mol·h), and viscosity-average molecular weight of polymer of up to 106 were obtained at optimum condition.
2002, 19(7): 621-624
Abstract:
Nine E,E-1-(3'-indolyl)-5-(substituted phenyl)-1,4-pentadien-3-one derivatives were synthesized and characterized by MS, 1H NMR and UV. Five of these compounds(1,3,4,6,7) showed a certain anti-inflammatory activity on mouse ear edema induced by croton oil with the inhibitions being 21.1%, 25.3%, 18.4%, 22.3% and 28.9% respectively (P<0.05 or P<0.01 vs control), at the hypodermic injection dose of 50 mg/kg.
Nine E,E-1-(3'-indolyl)-5-(substituted phenyl)-1,4-pentadien-3-one derivatives were synthesized and characterized by MS, 1H NMR and UV. Five of these compounds(1,3,4,6,7) showed a certain anti-inflammatory activity on mouse ear edema induced by croton oil with the inhibitions being 21.1%, 25.3%, 18.4%, 22.3% and 28.9% respectively (P<0.05 or P<0.01 vs control), at the hypodermic injection dose of 50 mg/kg.
2002, 19(7): 625-628
Abstract:
The fracture surface morphology of epoxy resin E-51/dicyandiamide(E-51/dicy) curing system toughened by chain-extended urea containing polyether has been investigated by SEM as function of the morphology, dynamic mechanical behavior and impact strength. The fracture surface of the modified systems was found to display tough fracture feature, markedly different from that of the unmodified system. A lot of microcave, i.e. microphase of rubber, could be observed in homogeneous distribution on the fractured surface of the modified systems. Presence of two-phase microstructure of the modified cured systems leads to the significant increase in impact strength. The impact strength of the modified system was affected by the amounts of chain-extended urea and the molecular mass of the PPG flexible spacer in the chain-extended urea, when the amounts of chain-extended urea was 14%(mass fraction), the highest impact strength of E-51/dicy/U1(extended-chain urea containing PPG flexible spacer with molecular mass 1 000) system was achieved which was 8 times that of the unmodified E-51/dicy curing system.
The fracture surface morphology of epoxy resin E-51/dicyandiamide(E-51/dicy) curing system toughened by chain-extended urea containing polyether has been investigated by SEM as function of the morphology, dynamic mechanical behavior and impact strength. The fracture surface of the modified systems was found to display tough fracture feature, markedly different from that of the unmodified system. A lot of microcave, i.e. microphase of rubber, could be observed in homogeneous distribution on the fractured surface of the modified systems. Presence of two-phase microstructure of the modified cured systems leads to the significant increase in impact strength. The impact strength of the modified system was affected by the amounts of chain-extended urea and the molecular mass of the PPG flexible spacer in the chain-extended urea, when the amounts of chain-extended urea was 14%(mass fraction), the highest impact strength of E-51/dicy/U1(extended-chain urea containing PPG flexible spacer with molecular mass 1 000) system was achieved which was 8 times that of the unmodified E-51/dicy curing system.
2002, 19(7): 629-632
Abstract:
A simultaneous determination of mannose, glucose and calcium gluconate formed in mannose production by using capillary zone electrophoresis combined with electrochemical detection(CE-ED) is reported. The effects of working electrode potential, running buffer concentration, separation voltage and injection time on the determination were examined. Mannose, glucose and calcium gluconate could be well separated in a 60 mmol/L NaOH buffer within 16 min. A 300μm diameter copper disk electrode was used as a working electrode at a potential of 0.65 V(vs.SCE). A good linear relationship between peak current and analyte concentration in the range of 2.0~0.01 mmol/L was obtained with detection limit of 6.1 μmol/L、7.1 μmol/L and 3.7 μmol/L for mannose, glucose and calcium gluconate, respectively. The RSD of the peak currents for the analytes were 3.6%, 2.4% and 3.8%(n=7), respectively. Recoveries for mannose, glucose and calcium gluconate were 100.6%, 100.1%, and 98.9%(n=3) respectively.
A simultaneous determination of mannose, glucose and calcium gluconate formed in mannose production by using capillary zone electrophoresis combined with electrochemical detection(CE-ED) is reported. The effects of working electrode potential, running buffer concentration, separation voltage and injection time on the determination were examined. Mannose, glucose and calcium gluconate could be well separated in a 60 mmol/L NaOH buffer within 16 min. A 300μm diameter copper disk electrode was used as a working electrode at a potential of 0.65 V(vs.SCE). A good linear relationship between peak current and analyte concentration in the range of 2.0~0.01 mmol/L was obtained with detection limit of 6.1 μmol/L、7.1 μmol/L and 3.7 μmol/L for mannose, glucose and calcium gluconate, respectively. The RSD of the peak currents for the analytes were 3.6%, 2.4% and 3.8%(n=7), respectively. Recoveries for mannose, glucose and calcium gluconate were 100.6%, 100.1%, and 98.9%(n=3) respectively.
2002, 19(7): 633-636
Abstract:
The electrochemical behavior of the nano-TiO2 electrode in different solutions were investigated by electrochemically transient methods, such as cyclic voltammetry, cyclic Osteryoung square wave voltammetry and linear potential sweep techniques as function of acid species, acidity, potential and temperature. The results showed that there were two pairs of reversible redox peaks, which were hardly affected by the acidity and anions of acids, and E1/2r in non-oxidative acid solutions(H2SO4,HCl) was -0.52 V and -0.86 V, respectively. However, in oxidative acid solutions(H2C2O4,HNO3), there appeared a surface heterogeneous electrocatalytic behavior, but electrochemically half reversible behavior, in alkaline and neutral solutions(KOH,KCl). The nano-TiO2 electrode behaved sluggishly in anode scan range of -0.5~1.5 V.
The electrochemical behavior of the nano-TiO2 electrode in different solutions were investigated by electrochemically transient methods, such as cyclic voltammetry, cyclic Osteryoung square wave voltammetry and linear potential sweep techniques as function of acid species, acidity, potential and temperature. The results showed that there were two pairs of reversible redox peaks, which were hardly affected by the acidity and anions of acids, and E1/2r in non-oxidative acid solutions(H2SO4,HCl) was -0.52 V and -0.86 V, respectively. However, in oxidative acid solutions(H2C2O4,HNO3), there appeared a surface heterogeneous electrocatalytic behavior, but electrochemically half reversible behavior, in alkaline and neutral solutions(KOH,KCl). The nano-TiO2 electrode behaved sluggishly in anode scan range of -0.5~1.5 V.
2002, 19(7): 637-640
Abstract:
A process neural network of learning and memory abilities, has been proposed in order to examine the relationship between the temperature-time reaction curve and the molecuar mass of polyacrylamide (PAA). The relative error of the molecular mass of PAA predicted by the process neural network was in 2% lower than that measured by chemical method, implying that the method proposed is simple and effective for a molecular mass determination of PAA.
A process neural network of learning and memory abilities, has been proposed in order to examine the relationship between the temperature-time reaction curve and the molecuar mass of polyacrylamide (PAA). The relative error of the molecular mass of PAA predicted by the process neural network was in 2% lower than that measured by chemical method, implying that the method proposed is simple and effective for a molecular mass determination of PAA.
2002, 19(7): 641-644
Abstract:
The thermodynamically preferred morphology of the composite latex of PVAc/PBA core shell particle in starved condition has been predicted by using the methods of Torza, Sundberg, Gonzalez-Ortiz and the simple interfacial tensions calculation. The PVAc/PBA particles having PVAc as shell and PBA as core could be observed in TEM photos. The emulsion of inverted core-shell structure has a potential use as an adhesive for degradable food container.
The thermodynamically preferred morphology of the composite latex of PVAc/PBA core shell particle in starved condition has been predicted by using the methods of Torza, Sundberg, Gonzalez-Ortiz and the simple interfacial tensions calculation. The PVAc/PBA particles having PVAc as shell and PBA as core could be observed in TEM photos. The emulsion of inverted core-shell structure has a potential use as an adhesive for degradable food container.
2002, 19(7): 645-648
Abstract:
The inhibitory or antibiotic actions of three kinds of the selenomorpholine derivatives on a strain of Escherichia coli have been studied by microcalorimetry. Differences in their abilities to inhibit the metabolism of this bacteria were observed. The extent and level of the inhibitory effect on the metabolism as judged by the rate constant, k, and the half-inhibitory concentration, IC50, varied with the kinds of drugs. The rate constant(k) of Escherichia coli in the presence of the drugs was found decreased with the increase in concentration of the drug. The experimental results revealed that the antibiotic activity of selenomorpholines was in order of: N-dodecyl-selenomorpholine-acetyl methyl ester bromide > N-dodecyl-selenomorpholine > 4-selenomorpholine-formylethyl ester.
The inhibitory or antibiotic actions of three kinds of the selenomorpholine derivatives on a strain of Escherichia coli have been studied by microcalorimetry. Differences in their abilities to inhibit the metabolism of this bacteria were observed. The extent and level of the inhibitory effect on the metabolism as judged by the rate constant, k, and the half-inhibitory concentration, IC50, varied with the kinds of drugs. The rate constant(k) of Escherichia coli in the presence of the drugs was found decreased with the increase in concentration of the drug. The experimental results revealed that the antibiotic activity of selenomorpholines was in order of: N-dodecyl-selenomorpholine-acetyl methyl ester bromide > N-dodecyl-selenomorpholine > 4-selenomorpholine-formylethyl ester.
2002, 19(7): 649-652
Abstract:
The separation of Zn(Ⅱ) by a floatation system consisted of sodium chloride, ammonium thiocyanate and crystal violet has been studied. The results showed that in the aqueous solutions Zn(Ⅱ) combines with ammonium thiocyanate and crystal violet(CV) into a ternary ion-association precipitate [Zn(SCN)42-]·(CV+)2. Presence of small quantity of sodium chloride caused the precipitate to be floated well on the surface of water phase and separated with water more completely. Zn(Ⅱ) can be completely separated from Fe(Ⅲ)、Al(Ⅲ)、Ni(Ⅱ)、Mn(Ⅱ)、Cd(Ⅱ) by floatation at pH 1~4 of water phase. The method is simple and rapid.
The separation of Zn(Ⅱ) by a floatation system consisted of sodium chloride, ammonium thiocyanate and crystal violet has been studied. The results showed that in the aqueous solutions Zn(Ⅱ) combines with ammonium thiocyanate and crystal violet(CV) into a ternary ion-association precipitate [Zn(SCN)42-]·(CV+)2. Presence of small quantity of sodium chloride caused the precipitate to be floated well on the surface of water phase and separated with water more completely. Zn(Ⅱ) can be completely separated from Fe(Ⅲ)、Al(Ⅲ)、Ni(Ⅱ)、Mn(Ⅱ)、Cd(Ⅱ) by floatation at pH 1~4 of water phase. The method is simple and rapid.
2002, 19(7): 653-656
Abstract:
A series of terpolymers(DPODPS/DPOBP/TPC) were prepared by low temperature solution polycondensation of 4,4'-diphenoxydiphenylsulfone(DPODPS), 4,4'-diphenoxybenzophenone(DPOBP) and terephthaloyl chloride(TPC) in 1,2-dichloroethane in the presence of AlCl3 and NMP. IR、WAXD、TG and DSC techniques were used to study the general properties of the copolymers. The results showed that the Tg and Td of the copolymers increased with the increase in DPODPS content, the Tm and Tc of the copolymer decreased with increase in DPODPS content. The terpolymers obtained have lower melting temperatures than polyether ketone ether ketone ketone(PEKEKK), and their heat-resistance properties are as good as that of PEKEKK.
A series of terpolymers(DPODPS/DPOBP/TPC) were prepared by low temperature solution polycondensation of 4,4'-diphenoxydiphenylsulfone(DPODPS), 4,4'-diphenoxybenzophenone(DPOBP) and terephthaloyl chloride(TPC) in 1,2-dichloroethane in the presence of AlCl3 and NMP. IR、WAXD、TG and DSC techniques were used to study the general properties of the copolymers. The results showed that the Tg and Td of the copolymers increased with the increase in DPODPS content, the Tm and Tc of the copolymer decreased with increase in DPODPS content. The terpolymers obtained have lower melting temperatures than polyether ketone ether ketone ketone(PEKEKK), and their heat-resistance properties are as good as that of PEKEKK.
2002, 19(7): 657-661
Abstract:
2-Mercaptoethanol self-assembled monolayer modified gold electrode(ME/Au SAMs) has been fabricated. The electrochemical behavior of metol (N-methyl p-aminophenol sulfate) and p-benzenediol at ME/Au SAMs have been studied. The modified electrode shows an excellent electrocatalytic activity for the oxidation of metol and p-benzenediol, and accelerates electron transfer rate. Diffusion coefficients for metol and p-benzenediol were 2.1×10-5cm2/s and 2.7×10-6cm2/s, respectively. The electrocatalysis mechanism has been studied. ATR-FTIR was used for the characterization of the ME/Au SAMs. The oxidation currents were linear in the range of 1.0×10-7~1.0×10-4mol/L for metol and 6.0×10-6~6.0×10-4mol/L for p-benzenediol, with the correlation coefficients of 0.999 2 and 0.999 6 by differential pulse voltammetry (DPV), and detection limit 2.0×10-8mol/L and 1.2×10-6mol/L for metol and p-benzenediol, respectively. The modified electrode can be used for the simultaneous determination of metol and p-benzenediol in photographic imaging agents. The method is simple, quick, sensitive and accurate.
2-Mercaptoethanol self-assembled monolayer modified gold electrode(ME/Au SAMs) has been fabricated. The electrochemical behavior of metol (N-methyl p-aminophenol sulfate) and p-benzenediol at ME/Au SAMs have been studied. The modified electrode shows an excellent electrocatalytic activity for the oxidation of metol and p-benzenediol, and accelerates electron transfer rate. Diffusion coefficients for metol and p-benzenediol were 2.1×10-5cm2/s and 2.7×10-6cm2/s, respectively. The electrocatalysis mechanism has been studied. ATR-FTIR was used for the characterization of the ME/Au SAMs. The oxidation currents were linear in the range of 1.0×10-7~1.0×10-4mol/L for metol and 6.0×10-6~6.0×10-4mol/L for p-benzenediol, with the correlation coefficients of 0.999 2 and 0.999 6 by differential pulse voltammetry (DPV), and detection limit 2.0×10-8mol/L and 1.2×10-6mol/L for metol and p-benzenediol, respectively. The modified electrode can be used for the simultaneous determination of metol and p-benzenediol in photographic imaging agents. The method is simple, quick, sensitive and accurate.
2002, 19(7): 662-666
Abstract:
The NMR results indicated that toluene is a selective solvent for amphiphilic graft copolymer poly(methyl methylacrylate)-g-poly(ethylene oxide)(PMMA-g-PEO). The reversed-micelles were formed in toluene with PEO side chains as core and PMMA backbones as shells. TEM, DLS and viscosity measurement revealed that the aggregation structure is dependent on the temperature and concentration of the PMMA-g-PEO solution, at higher temperature the reversed-micelle can be formed in a lower concentration. The aggregation structure is changed in a certain range of concentration and temperature, as shown in following schemes. (1) Single molecular solution ???20020713-3??? Small reversed-micelle ???20020713-3??? Large reversed micelle (2) Large reversed-micelle ???20020713-4??? Smalle reversed-micelle ???20020713-4??? Single molecular solution
The NMR results indicated that toluene is a selective solvent for amphiphilic graft copolymer poly(methyl methylacrylate)-g-poly(ethylene oxide)(PMMA-g-PEO). The reversed-micelles were formed in toluene with PEO side chains as core and PMMA backbones as shells. TEM, DLS and viscosity measurement revealed that the aggregation structure is dependent on the temperature and concentration of the PMMA-g-PEO solution, at higher temperature the reversed-micelle can be formed in a lower concentration. The aggregation structure is changed in a certain range of concentration and temperature, as shown in following schemes. (1) Single molecular solution ???20020713-3??? Small reversed-micelle ???20020713-3??? Large reversed micelle (2) Large reversed-micelle ???20020713-4??? Smalle reversed-micelle ???20020713-4??? Single molecular solution
2002, 19(7): 667-671
Abstract:
Six title complexes have been prepared from dimethylcyclopentadienyl dichloro titanium and salicylic acid, mercaptosalicylic acid, 5-nitrosalicylic acid, 3,5-dinitrosalicylic acid via aqueous-phase and two-phase processes. The IR and 1H NMR spectra of the complexes are discussed briefly.
Six title complexes have been prepared from dimethylcyclopentadienyl dichloro titanium and salicylic acid, mercaptosalicylic acid, 5-nitrosalicylic acid, 3,5-dinitrosalicylic acid via aqueous-phase and two-phase processes. The IR and 1H NMR spectra of the complexes are discussed briefly.
2002, 19(7): 672-676
Abstract:
In an aqueous solution of pH=5.0~8.2, H aggregates of Quinaldine Blue(QB) are formed with the nucleic acid molecules. QB showed a decrease in absorbance at peak wavelength of 598 nm or 548 nm on binding to nucleic acids. A new assay method for nucleic acids was thus developed based on clear decrease of QB absorbance at 598 nm. The calibration curves are linear in the range of 8.0×10-8~2.0×10-6g/mL for ctDNA, 1.0×10-7~2.0×10-6g/mL for yRNA, respectively. The reliabilities of five determinations of 1.0 μg/mL nucleic acids were 3.4% for ctDNA and 3.6% for yRNA, respectively. The method was featured by its rapidity, simplicity, sensitivity and good selectivity. It has been used to determine both synthetic and real samples with satisfactory results.
In an aqueous solution of pH=5.0~8.2, H aggregates of Quinaldine Blue(QB) are formed with the nucleic acid molecules. QB showed a decrease in absorbance at peak wavelength of 598 nm or 548 nm on binding to nucleic acids. A new assay method for nucleic acids was thus developed based on clear decrease of QB absorbance at 598 nm. The calibration curves are linear in the range of 8.0×10-8~2.0×10-6g/mL for ctDNA, 1.0×10-7~2.0×10-6g/mL for yRNA, respectively. The reliabilities of five determinations of 1.0 μg/mL nucleic acids were 3.4% for ctDNA and 3.6% for yRNA, respectively. The method was featured by its rapidity, simplicity, sensitivity and good selectivity. It has been used to determine both synthetic and real samples with satisfactory results.
2002, 19(7): 677-681
Abstract:
A novel type of biological microcapsule consisted of carboxymethyl chitosan, chitosan and carboxymethyl chitosan(CCC) was prepared as ion replacement gels. In addition, two modified ion replacement gels, alginate-chitosan-alginate/carboxymethyl chitosan/glutaraldehyde(ACA/CMC/GA) and alginate-chitosan-alginate/oligo-chitosan/glutaraldehyde(ACA/O-Chs/GA), were prepared. All of the ion replacement gels prepared exhibited good ion replacement properties and could be used for adsorption of Pb2+ at higher rate. Among them the ACA/O-Chs/GA appeared the best one.
A novel type of biological microcapsule consisted of carboxymethyl chitosan, chitosan and carboxymethyl chitosan(CCC) was prepared as ion replacement gels. In addition, two modified ion replacement gels, alginate-chitosan-alginate/carboxymethyl chitosan/glutaraldehyde(ACA/CMC/GA) and alginate-chitosan-alginate/oligo-chitosan/glutaraldehyde(ACA/O-Chs/GA), were prepared. All of the ion replacement gels prepared exhibited good ion replacement properties and could be used for adsorption of Pb2+ at higher rate. Among them the ACA/O-Chs/GA appeared the best one.
2002, 19(7): 682-686
Abstract:
The permanent magnetic BaFe12O19 powder with average particle size of 50 nm was synthesized by a method consisted of independent nucleation and crystallization steps and subsequent heat treatment starting materials from Ba(NO3)2, Fe(NO3)2 and NH4HCO3·NH2COONH4. The effects of heat treatment temperatures on the particle size, microstructure and magnetic properties of the powder have been studied by XRD, TEM and VSM techniques. The results showed that the hematite T-Fe2O3 was the main phase in the powder at heat treatment temperatures below 650℃ and its amount in the powder decreased with increase of temperature. However small amounts of T-Fe2O3 still remained in the powder after being heated at 900℃ for 8 h. BaFe12O19 was formed at about 650℃ and its amount in the powder increased with increase of temperature. It needed more high temperature to attain considerable amount of BaFe12O19 and ideal nanosize BaFe12O19 particle in the powder. The particle size also increased with temperature. Heating at 800℃ for 8 h gave a uniform particle size distribution, and heating at 900℃ for 8 h a typical hexagonal shape and chain aggregation were observed. The specific saturation magnetization strength, specific residual magnetization strength and coercive force all increased with temperatuer from 650℃ to 900℃ and reached 39.83 A·m2/kg, 23.96A·m2/kg and 480 kA/m at 900℃ respectively.
The permanent magnetic BaFe12O19 powder with average particle size of 50 nm was synthesized by a method consisted of independent nucleation and crystallization steps and subsequent heat treatment starting materials from Ba(NO3)2, Fe(NO3)2 and NH4HCO3·NH2COONH4. The effects of heat treatment temperatures on the particle size, microstructure and magnetic properties of the powder have been studied by XRD, TEM and VSM techniques. The results showed that the hematite T-Fe2O3 was the main phase in the powder at heat treatment temperatures below 650℃ and its amount in the powder decreased with increase of temperature. However small amounts of T-Fe2O3 still remained in the powder after being heated at 900℃ for 8 h. BaFe12O19 was formed at about 650℃ and its amount in the powder increased with increase of temperature. It needed more high temperature to attain considerable amount of BaFe12O19 and ideal nanosize BaFe12O19 particle in the powder. The particle size also increased with temperature. Heating at 800℃ for 8 h gave a uniform particle size distribution, and heating at 900℃ for 8 h a typical hexagonal shape and chain aggregation were observed. The specific saturation magnetization strength, specific residual magnetization strength and coercive force all increased with temperatuer from 650℃ to 900℃ and reached 39.83 A·m2/kg, 23.96A·m2/kg and 480 kA/m at 900℃ respectively.
2002, 19(7): 687-689
Abstract:
Thifensulfuron was synthesized in two steps by reacting bis(trichloromethyl) carbonate(BTC) as a phosgene substitute with 2-methoxycarbonyl-3-aminosulfonylthiophene(AST) to give an intermediate sulfonylisocynate, which reacted with 2-amino-4-methoxy-6-methyl-1,3,5-triazine to give thifensulfuron. The optimum reaction conditions were n(AST):n(BTC)=1:0.56, reaction temperature 120~130℃ and reaction time (11±0.5) h. The purity of thifensulfuron obtained was 96.5%(HPLC) in overall yield 93%.
Thifensulfuron was synthesized in two steps by reacting bis(trichloromethyl) carbonate(BTC) as a phosgene substitute with 2-methoxycarbonyl-3-aminosulfonylthiophene(AST) to give an intermediate sulfonylisocynate, which reacted with 2-amino-4-methoxy-6-methyl-1,3,5-triazine to give thifensulfuron. The optimum reaction conditions were n(AST):n(BTC)=1:0.56, reaction temperature 120~130℃ and reaction time (11±0.5) h. The purity of thifensulfuron obtained was 96.5%(HPLC) in overall yield 93%.
2002, 19(7): 690-692
Abstract:
A copolyester hot-melt adhesive was prepared by transesterification, esterificcation and polycondensation from dimethylterephthalate(DMT), dicarboxylic acid and dihydric alcohol. The influences of nucleating agents and crystallizing promoter on its crystallization kinetics was studied by measurement of depolarized light intensity with time. It was found that the complex additives composed of inorganic nucleating agent, organic agents and crystallization promoter could significantly accelerate the crystallization process of the copolyester due to the reduction of the activation energies of crystal nucleation and crystal growth.
A copolyester hot-melt adhesive was prepared by transesterification, esterificcation and polycondensation from dimethylterephthalate(DMT), dicarboxylic acid and dihydric alcohol. The influences of nucleating agents and crystallizing promoter on its crystallization kinetics was studied by measurement of depolarized light intensity with time. It was found that the complex additives composed of inorganic nucleating agent, organic agents and crystallization promoter could significantly accelerate the crystallization process of the copolyester due to the reduction of the activation energies of crystal nucleation and crystal growth.
2002, 19(7): 693-695
Abstract:
Methyl acrylate has been grafted on the surface of carbon black through hydromethyl group, which was introduced onto carbon black by reaction with formaldehyde in NaOH solution. The copolymerization was initiated by manganese acetylacetonate. Hydrolysis of the grafted chain improved the stability of hydrolyzed grafted carbon black dispersion in water. The grafted carbon black was characterized by AFM. Orthogonal experiment shows that the optimum concentrations of initiator,momomer and carbon black are 12 mmol/L, 0.4 mol/L and 1:80(mass ratio of carbon black to total mass of the system) respectively in graft copolymeriation.
Methyl acrylate has been grafted on the surface of carbon black through hydromethyl group, which was introduced onto carbon black by reaction with formaldehyde in NaOH solution. The copolymerization was initiated by manganese acetylacetonate. Hydrolysis of the grafted chain improved the stability of hydrolyzed grafted carbon black dispersion in water. The grafted carbon black was characterized by AFM. Orthogonal experiment shows that the optimum concentrations of initiator,momomer and carbon black are 12 mmol/L, 0.4 mol/L and 1:80(mass ratio of carbon black to total mass of the system) respectively in graft copolymeriation.
2002, 19(7): 696-698
Abstract:
The effect of pH value on the CaM(Calmodulin) self-assembled membrane Au electrode was studied by CV method, where the redox couple of Fe(CN)63-/Fe(CN)64- was employed as a probe. The results indicated the formation of the self-assembled monolayer of CaM that the structure of this membrane is different in various acid/base environment, and the stronger the base, the denser the membrane. The work is meaningful to detect CaM by using electrochemical method.
The effect of pH value on the CaM(Calmodulin) self-assembled membrane Au electrode was studied by CV method, where the redox couple of Fe(CN)63-/Fe(CN)64- was employed as a probe. The results indicated the formation of the self-assembled monolayer of CaM that the structure of this membrane is different in various acid/base environment, and the stronger the base, the denser the membrane. The work is meaningful to detect CaM by using electrochemical method.
2002, 19(7): 699-701
Abstract:
The electrochemical properties of LiCr0.1Mn1.9O4 as a cathode material in five electrolyte solutions, LiPF6/EC+DEC, LiPF6/EC+EMC, LiPF6/EC+DME, LiPF6/EC+DMC and LiBF4/ EC+ DMC have been studied. The initial capacity values were very close each to other for the electrolyte solutions examined. However, the capacity fading and self-discharge data obtained from the cells with above electrolyte solutions were different in the order of LiPF6/EC+DME > LiPF6/EC+EMC >> LiPF6/EC+DMC≈LiPF6/EC+DEC≈LiBF4/EC+DMC. Decrease of the electrochemical properties was attributed mainly to the electrolyte decompositions on the surface of the electrodes. LiPF6/EC+DEC, LiPF6/EC+DMC and LiBF4/EC+DMC appeared electrolytes well compatible with LiCr0.1Mn1.9O4 electrode.
The electrochemical properties of LiCr0.1Mn1.9O4 as a cathode material in five electrolyte solutions, LiPF6/EC+DEC, LiPF6/EC+EMC, LiPF6/EC+DME, LiPF6/EC+DMC and LiBF4/ EC+ DMC have been studied. The initial capacity values were very close each to other for the electrolyte solutions examined. However, the capacity fading and self-discharge data obtained from the cells with above electrolyte solutions were different in the order of LiPF6/EC+DME > LiPF6/EC+EMC >> LiPF6/EC+DMC≈LiPF6/EC+DEC≈LiBF4/EC+DMC. Decrease of the electrochemical properties was attributed mainly to the electrolyte decompositions on the surface of the electrodes. LiPF6/EC+DEC, LiPF6/EC+DMC and LiBF4/EC+DMC appeared electrolytes well compatible with LiCr0.1Mn1.9O4 electrode.
2002, 19(7): 702-704
Abstract:
The inclusion interactions between flavonoids and U-cyclodextrin(U-CD) and its derivatives have been studied by a phase solubility method. The phase solubility graphs showed that the 1:1 inclusion compounds were formed beween U-CD and rutin, qucertin and morin respectively. The compounds appeared to be a type of AL inclusion. U-CD derivatives have stronger binding capacity than U-CD. The enhanced solubility of compounds decreased in the order methyl-U-CD > hydroxypropyl-U-CD > U-CD. The highest solubility was obtained in methyl-U-CD inclusion complex with qucertin in level of 50 times than that in water.
The inclusion interactions between flavonoids and U-cyclodextrin(U-CD) and its derivatives have been studied by a phase solubility method. The phase solubility graphs showed that the 1:1 inclusion compounds were formed beween U-CD and rutin, qucertin and morin respectively. The compounds appeared to be a type of AL inclusion. U-CD derivatives have stronger binding capacity than U-CD. The enhanced solubility of compounds decreased in the order methyl-U-CD > hydroxypropyl-U-CD > U-CD. The highest solubility was obtained in methyl-U-CD inclusion complex with qucertin in level of 50 times than that in water.
Determination of Glucose by Flow Injection Chemiluminesence Analysis with Coupled Oxidation Reaction
2002, 19(7): 705-707
Abstract:
A flow injection chemiluminesence analysis coupled with enzymic oxidation reaction for the determination of glucose is proposed. The linear range for glucose is 0.6~110 mg/L with a correlation coefficient of 0.999 7 and the detection limit 0.08 mg/L. The relative standard deviation (n=11) is 1.3% for 10 mg/L glucose. The method has been applied to the determination of glucose in human serum with satisfactory results.
A flow injection chemiluminesence analysis coupled with enzymic oxidation reaction for the determination of glucose is proposed. The linear range for glucose is 0.6~110 mg/L with a correlation coefficient of 0.999 7 and the detection limit 0.08 mg/L. The relative standard deviation (n=11) is 1.3% for 10 mg/L glucose. The method has been applied to the determination of glucose in human serum with satisfactory results.
2002, 19(7): 708-710
Abstract:
The precursor Cu(acac)2 was electrochemically prepared by anodic dissolution of fresh metallic copper in absolute acetylacetone using Bu4N·Br as supporting electrolyte. Nanocrystalline CuO could be obtained by direct hydrolysis of the electrolyte solution via refluxing with some amount of NaOH and water. FTIR, elemental analysis, XRD and TEM have been used to investigate the structure of the precursor and nanocrystalline CuO. The results showed that the cupric oxide obtained is of spherical structure with size distribution ranged in 10 nm to 20 nm. The rational electrode potential in electrolysis appeared to be 1.2~1.8 V(vs.SCE).
The precursor Cu(acac)2 was electrochemically prepared by anodic dissolution of fresh metallic copper in absolute acetylacetone using Bu4N·Br as supporting electrolyte. Nanocrystalline CuO could be obtained by direct hydrolysis of the electrolyte solution via refluxing with some amount of NaOH and water. FTIR, elemental analysis, XRD and TEM have been used to investigate the structure of the precursor and nanocrystalline CuO. The results showed that the cupric oxide obtained is of spherical structure with size distribution ranged in 10 nm to 20 nm. The rational electrode potential in electrolysis appeared to be 1.2~1.8 V(vs.SCE).
2002, 19(7): 711-712
Abstract:
The ozonization of turpentine, T-Pinene and U-Pinene mixture in ethanol were studied by gas chromatography. The reactivity order is T-Pinene>U-Pinene and the ratio of kinetic rate constants, T-Pinene kA and U-Pinene kB is kA/kB=7.0.
The ozonization of turpentine, T-Pinene and U-Pinene mixture in ethanol were studied by gas chromatography. The reactivity order is T-Pinene>U-Pinene and the ratio of kinetic rate constants, T-Pinene kA and U-Pinene kB is kA/kB=7.0.
2002, 19(7): 713-714
Abstract:
Four gemini cationic surfactants were synthesized by N-alkylation reaction of N,N-dimethyl dodecyl amine with 1,2-ethanediol dichloracetate, 1,3-propanediol dichloracetate, 1,4-butanediol dichloracetate and 1,6-hexanediol dichloracetate, respectively. The molecular structures of the surfactants were characterized by IR and 1H NMR spectra. The cmc values of gemini cationic surfactants SAA1, SAA2, SAA3, SAA4 were 0.91, 0.34, 0.35 and 0.78 mmol/L, respectively, much lower than that of the corresponding conventional single tailed surfactant[C12H25N(CH3)2CH2-COOC2H5]+Cl-, whose cmc is 8.9 mmol/L. Their foaming capacity was 162, 171, 160, 168 mm, respectively, higher than 157 mm for[C12H25N(CH3)2CH2COOC2H5]+Cl-.
Four gemini cationic surfactants were synthesized by N-alkylation reaction of N,N-dimethyl dodecyl amine with 1,2-ethanediol dichloracetate, 1,3-propanediol dichloracetate, 1,4-butanediol dichloracetate and 1,6-hexanediol dichloracetate, respectively. The molecular structures of the surfactants were characterized by IR and 1H NMR spectra. The cmc values of gemini cationic surfactants SAA1, SAA2, SAA3, SAA4 were 0.91, 0.34, 0.35 and 0.78 mmol/L, respectively, much lower than that of the corresponding conventional single tailed surfactant[C12H25N(CH3)2CH2-COOC2H5]+Cl-, whose cmc is 8.9 mmol/L. Their foaming capacity was 162, 171, 160, 168 mm, respectively, higher than 157 mm for[C12H25N(CH3)2CH2COOC2H5]+Cl-.
