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2004 Volume 15 Issue 9
2004, 15(9): 1009-1010
Abstract:
The solid-phase synthesis of unsaturated β-dicarbonyl compounds has been reported.
The solid-phase synthesis of unsaturated β-dicarbonyl compounds has been reported.
2004, 15(9): 1011-1014
Abstract:
Based on our previous studies of 3D-QSAR, 38 novel objective compounds belonging to 4 series were designed and successfully synthesized directed by the idea of reconstructing the structure of non-pharmacophores while reserving essential ones in triazoles. In vitro pilot studies on their antifungal activities showed that most compounds have inhibitory effects on C.albicans and some inhibit S.cerevisiae also. The effects on C.albicans of 5 compounds are more potent than or equal to that of fluconazole or itraconazole.
Based on our previous studies of 3D-QSAR, 38 novel objective compounds belonging to 4 series were designed and successfully synthesized directed by the idea of reconstructing the structure of non-pharmacophores while reserving essential ones in triazoles. In vitro pilot studies on their antifungal activities showed that most compounds have inhibitory effects on C.albicans and some inhibit S.cerevisiae also. The effects on C.albicans of 5 compounds are more potent than or equal to that of fluconazole or itraconazole.
2004, 15(9): 1015-1018
Abstract:
Four chiral 1,1'-bis(oxazolinyl)ferrocenes(1a-1d) have been prepared and used as ligands in the copper catalyzed asymmetric cyclopropanation of styrene with ethyl diazoacetate (EDA) and the magnesium catalyzed Diels-Alder reaction between 3-acryloyl-2-oxazolidinone and cyclopentadiene. Enantioselectivities up to 24% and 41%, respectively, for cyclopropanation and Diels-Alder reaction were observed.
Four chiral 1,1'-bis(oxazolinyl)ferrocenes(1a-1d) have been prepared and used as ligands in the copper catalyzed asymmetric cyclopropanation of styrene with ethyl diazoacetate (EDA) and the magnesium catalyzed Diels-Alder reaction between 3-acryloyl-2-oxazolidinone and cyclopentadiene. Enantioselectivities up to 24% and 41%, respectively, for cyclopropanation and Diels-Alder reaction were observed.
2004, 15(9): 1019-1021
Abstract:
Three different synthetic routes were developed to introduce carbamoyloxy functional groups at the upper periphery of two calix[4]resorcinarenes. By treating activated esters 2a-b with excess corresponding amine such as 3-(dimethylamino)propylamine 3, α-phenethylamine 4 and triethylenetetramine 5, six amide derivatives 6a~8b were obtained in high yield (Route 1). The pyridine-linked amide derivatives 9a-b were prepared by using acid chloride intermediate (Route 2). The amide derivatives 10a-b were obtained in moderate yields by direct alkylation of phenolic hydroxyl groups of 1a-b with N,N-dipropylchloroacetoamide in the presence of K2CO3/KI in acetone (Route 3).
Three different synthetic routes were developed to introduce carbamoyloxy functional groups at the upper periphery of two calix[4]resorcinarenes. By treating activated esters 2a-b with excess corresponding amine such as 3-(dimethylamino)propylamine 3, α-phenethylamine 4 and triethylenetetramine 5, six amide derivatives 6a~8b were obtained in high yield (Route 1). The pyridine-linked amide derivatives 9a-b were prepared by using acid chloride intermediate (Route 2). The amide derivatives 10a-b were obtained in moderate yields by direct alkylation of phenolic hydroxyl groups of 1a-b with N,N-dipropylchloroacetoamide in the presence of K2CO3/KI in acetone (Route 3).
2004, 15(9): 1022-1024
Abstract:
The promotion effect of cationic gemini surfactants for the hydroformylation of 1-dodecene in the organic/aqueous biphasic catalytic system is reported. The hydroformylation reaction in the presence of gemini surfactant occurred with higher turnover frequency and higher selectivity for linear aldehyde than using conventional monomeric surfactant CTAB.
The promotion effect of cationic gemini surfactants for the hydroformylation of 1-dodecene in the organic/aqueous biphasic catalytic system is reported. The hydroformylation reaction in the presence of gemini surfactant occurred with higher turnover frequency and higher selectivity for linear aldehyde than using conventional monomeric surfactant CTAB.
2004, 15(9): 1025-1028
Abstract:
Three chiral N-ferrocenylmethylaminoalcohols were synthesized from readily available natural L-valine, leucine and phenylanine, and used as chiral ligands in the enantioselective addition of diethylzinc to aldehydes.
Three chiral N-ferrocenylmethylaminoalcohols were synthesized from readily available natural L-valine, leucine and phenylanine, and used as chiral ligands in the enantioselective addition of diethylzinc to aldehydes.
2004, 15(9): 1029-1032
Abstract:
The oxidation of α,β-unsaturated primary and secondary alcohols to corresponding aldehydes and ketones by manganese dioxide in ionic liquids as a safe recyclable and accelerative reaction medium under mild conditions are described. The rate of the oxidation reaction is faster and the yield is higher than that with conventional procedures.
The oxidation of α,β-unsaturated primary and secondary alcohols to corresponding aldehydes and ketones by manganese dioxide in ionic liquids as a safe recyclable and accelerative reaction medium under mild conditions are described. The rate of the oxidation reaction is faster and the yield is higher than that with conventional procedures.
2004, 15(9): 1033-1035
Abstract:
An unusual formation of cyclic sulfite at C-4 and C-5 positions of taxane was accomplished by treatment of compound 1 with excess MeSO2Cl/Et3N and a possible mechanism was proposed.
An unusual formation of cyclic sulfite at C-4 and C-5 positions of taxane was accomplished by treatment of compound 1 with excess MeSO2Cl/Et3N and a possible mechanism was proposed.
2004, 15(9): 1036-1038
Abstract:
(±)-Aiphanol was first synthesized in which coupling reaction and Horner-Wittig reaction as the key steps.
(±)-Aiphanol was first synthesized in which coupling reaction and Horner-Wittig reaction as the key steps.
2004, 15(9): 1039-1042
Abstract:
A series of ethyl 6-bromo-5-hydroxyindole-3-carboxylate derivatives were synthesized and their in vitro anti-influenza virus activity was evaluated. All the compounds were characterized by 1H NMR and MS.
A series of ethyl 6-bromo-5-hydroxyindole-3-carboxylate derivatives were synthesized and their in vitro anti-influenza virus activity was evaluated. All the compounds were characterized by 1H NMR and MS.
2004, 15(9): 1043-1046
Abstract:
α-Aminonitriles were prepared efficiently from anodic cyanation of α-amino ester. The effect of different solvents and electrolytes was studied. The other byproducts were analyzed.
α-Aminonitriles were prepared efficiently from anodic cyanation of α-amino ester. The effect of different solvents and electrolytes was studied. The other byproducts were analyzed.
2004, 15(9): 1047-1049
Abstract:
Polystyrene-supported selenomethyl-sulfonates have been prepared. These novel reagents were treated with LDA to produce selenium stabilized carbanions, which reacted with alkyl halide and epoxides, followed by selenoxide syn-elimination, to give E-vinyl sulfones and γ-hydroxy-substituted-E-vinyl sulfones respectively.
Polystyrene-supported selenomethyl-sulfonates have been prepared. These novel reagents were treated with LDA to produce selenium stabilized carbanions, which reacted with alkyl halide and epoxides, followed by selenoxide syn-elimination, to give E-vinyl sulfones and γ-hydroxy-substituted-E-vinyl sulfones respectively.
2004, 15(9): 1050-1052
Abstract:
The novel dicyanate ester resin containing naphthalene unit (DNCY) was synthesized, and characterized by FT-IR, 1H-NMR, 13C-NMR and elemental analysis (EA).The thermal properties of DNCY resin was studied by thermal degradation analysis at a heating rate of 10 ℃/min-1 in N2 and air. The DNCY resin exhibited better thermal and thermal-oxidative stability than bisphenol A dicyanate (BACY) resin.
The novel dicyanate ester resin containing naphthalene unit (DNCY) was synthesized, and characterized by FT-IR, 1H-NMR, 13C-NMR and elemental analysis (EA).The thermal properties of DNCY resin was studied by thermal degradation analysis at a heating rate of 10 ℃/min-1 in N2 and air. The DNCY resin exhibited better thermal and thermal-oxidative stability than bisphenol A dicyanate (BACY) resin.
2004, 15(9): 1053-1056
Abstract:
A new lignanoside, saikolignanoside A, was isolated from the roots of Bupleurum scorzonerifolium. Its structure was determined as 3-methoxy-4-hydroxy-5-[(8'S)-3'-methoxy-4'-hydroxyphenylpropyl alcohol]-E-cinnamic alcohol-4-O-β-D-glucopyranoside by means of NMR and MS analysis, acid hydrolysis and optical data.
A new lignanoside, saikolignanoside A, was isolated from the roots of Bupleurum scorzonerifolium. Its structure was determined as 3-methoxy-4-hydroxy-5-[(8'S)-3'-methoxy-4'-hydroxyphenylpropyl alcohol]-E-cinnamic alcohol-4-O-β-D-glucopyranoside by means of NMR and MS analysis, acid hydrolysis and optical data.
2004, 15(9): 1057-1059
Abstract:
Two new isoquinoline alkaloids:carcrisine A and B, have been isolated from the whole plant of Carduus crispus L.. Their structures were elucidated by chemical and spectroscopic methods.
Two new isoquinoline alkaloids:carcrisine A and B, have been isolated from the whole plant of Carduus crispus L.. Their structures were elucidated by chemical and spectroscopic methods.
2004, 15(9): 1060-1062
Abstract:
In this article, a new and effective stationary phase based on ionic liquid modified silica is first reported and used for the separation of ephedrines in high-performance liquid chromatography (HPLC). The separation results indicate the high efficiency and reproducibility of the stationary phase. The electrostatic interaction, ion-exchange interaction between the solutes and the stationary phase are considered to attribute the effective separation. Moreover, the free silanols on the surface of the silica are effectively masked by the immobilized ionic liquid, a result of which is to decrease the non-specific absorption.
In this article, a new and effective stationary phase based on ionic liquid modified silica is first reported and used for the separation of ephedrines in high-performance liquid chromatography (HPLC). The separation results indicate the high efficiency and reproducibility of the stationary phase. The electrostatic interaction, ion-exchange interaction between the solutes and the stationary phase are considered to attribute the effective separation. Moreover, the free silanols on the surface of the silica are effectively masked by the immobilized ionic liquid, a result of which is to decrease the non-specific absorption.
2004, 15(9): 1063-1066
Abstract:
A mixture of nine biphenyl nitrile compounds with high hydrophobicity and similar structures was successfully separated by microemulsion electrokinetic chromatography (MEEKC) within 30 min. The buffer system contained 100 mmol/L sodium dodecyl sulfate (SDS), 80 mmol/L sodium cholate (SC), 0.81% heptane, 7.5% n-butanol, 10% acetonitrile and 10 mmol/L borate. The addition of SC, organic modifiers, sample preparation and temperature all showed remarkable effect on the separation. Meanwhile, the MEEKC method was briefly compared with micellar electrokinetic chromatography (MEKC) method.
A mixture of nine biphenyl nitrile compounds with high hydrophobicity and similar structures was successfully separated by microemulsion electrokinetic chromatography (MEEKC) within 30 min. The buffer system contained 100 mmol/L sodium dodecyl sulfate (SDS), 80 mmol/L sodium cholate (SC), 0.81% heptane, 7.5% n-butanol, 10% acetonitrile and 10 mmol/L borate. The addition of SC, organic modifiers, sample preparation and temperature all showed remarkable effect on the separation. Meanwhile, the MEEKC method was briefly compared with micellar electrokinetic chromatography (MEKC) method.
2004, 15(9): 1067-1070
Abstract:
A new method for the determination of baicalin with HPLC-CL was developed. The method was based on the chemiluminescence reaction between KMnO4 and baicalin sensitized from HCHO. The linear range was 3.7×10-6~9.8×10-5 mol/L with detection limit of 1.7×10-6 mol/L and the relative standard deviation was 2.5% (Cs=6.6×10-5 mol/L, n=5). The method has been applied to the determination of baicalin in oral administration, injection, Scutellariae radix and granules with good results.
A new method for the determination of baicalin with HPLC-CL was developed. The method was based on the chemiluminescence reaction between KMnO4 and baicalin sensitized from HCHO. The linear range was 3.7×10-6~9.8×10-5 mol/L with detection limit of 1.7×10-6 mol/L and the relative standard deviation was 2.5% (Cs=6.6×10-5 mol/L, n=5). The method has been applied to the determination of baicalin in oral administration, injection, Scutellariae radix and granules with good results.
2004, 15(9): 1071-1074
Abstract:
An electrospray ionization/tandem mass spectrometric (ESI/MS/MS) method was developed for the simultaneous identification and analysis of three aconitine alkaloids[mesacontine (MA), hypaconitine (HA), and aconitine (A)] as intact molecules at low nanogram level in Chinese traditional medicine Chuanwu decoction as well as in human whole blood extract without chromatographic separation.
An electrospray ionization/tandem mass spectrometric (ESI/MS/MS) method was developed for the simultaneous identification and analysis of three aconitine alkaloids[mesacontine (MA), hypaconitine (HA), and aconitine (A)] as intact molecules at low nanogram level in Chinese traditional medicine Chuanwu decoction as well as in human whole blood extract without chromatographic separation.
2004, 15(9): 1075-1078
Abstract:
The thermokinetic behavior of the B-Z reaction system was influenced by both the chemical reaction-heat conduction coupling and the temperature undulation due to temperature controlling of heat compensation type. Quantitative research indicated that this kind of temperature fluctuation will lead to limit cycle degeneration and the periodic or quasi-periodic response behavior of the focus near a supercritical Hopf bifurcation.
The thermokinetic behavior of the B-Z reaction system was influenced by both the chemical reaction-heat conduction coupling and the temperature undulation due to temperature controlling of heat compensation type. Quantitative research indicated that this kind of temperature fluctuation will lead to limit cycle degeneration and the periodic or quasi-periodic response behavior of the focus near a supercritical Hopf bifurcation.
2004, 15(9): 1079-1082
Abstract:
The interactions between amnesic red-tide toxin, domoic acid (DA) and 14mer double-stranded DNA (dsDNA with three kinds of sequences) were studied by capillary zone electrophoresis (CZE). For the dsDNA with a sequence of 5'-CCCCCTATACCCGC-3', the amount of free dsDNA decreases with the increase of added DA; and the signal of DA-dsDNA complex was observed. Meanwhile, the other two dsDNAs, 5'-(C)12GC-3' and 5'-(AT)7-3', the existence of DA could not lead to the change of dsDNA signal and indicated that there is no interaction between DA and these two dsDNAs.
The interactions between amnesic red-tide toxin, domoic acid (DA) and 14mer double-stranded DNA (dsDNA with three kinds of sequences) were studied by capillary zone electrophoresis (CZE). For the dsDNA with a sequence of 5'-CCCCCTATACCCGC-3', the amount of free dsDNA decreases with the increase of added DA; and the signal of DA-dsDNA complex was observed. Meanwhile, the other two dsDNAs, 5'-(C)12GC-3' and 5'-(AT)7-3', the existence of DA could not lead to the change of dsDNA signal and indicated that there is no interaction between DA and these two dsDNAs.
2004, 15(9): 1083-1086
Abstract:
The spectral properties of the glutaraldehyde-treated phycobilisomes were studied. The results showed that glutaraldehyde was effective in preventing phycobilisomes from dilutioninduced dissociation and preserving the intra-phycobilisomes energy transfer.
The spectral properties of the glutaraldehyde-treated phycobilisomes were studied. The results showed that glutaraldehyde was effective in preventing phycobilisomes from dilutioninduced dissociation and preserving the intra-phycobilisomes energy transfer.
Synthesis and Characterization of Novel Mercapto-end Ferrocenyl Derivatives with Schiff Base Linkage
2004, 15(9): 1087-1090
Abstract:
Novel ferrocenyl derivatives of p-(10-mercaptodecyloxy) benzal 4-ferrocenylaniline have been prepared and characterized by element analysis, 1HNMR, and FAB-MS. Cyclic voltammetry has been used to characterize the self-assembled monolayers formed from the compounds on the gold electrodes.
Novel ferrocenyl derivatives of p-(10-mercaptodecyloxy) benzal 4-ferrocenylaniline have been prepared and characterized by element analysis, 1HNMR, and FAB-MS. Cyclic voltammetry has been used to characterize the self-assembled monolayers formed from the compounds on the gold electrodes.
2004, 15(9): 1091-1094
Abstract:
In this paper, we first presented a novel method for quantification of circulating DNA in human serum based on capillary zone electrophoresis with laser-induced fluorescence detection (CZE-LIF). The serum was digested by proteinase to release free DNA, and then CZE-LIF system was used for the quantification of total circulating DNA. This method was successfully used to quantify the circulating DNA levels in sera from healthy individuals and certain cancer patients. We found the significantly elevated circulating DNA levels in certain prostate cancer patients. Our results demonstrated that CZE-LIF system has good linearity, excellent sensitivity (0.5 ng/mL DNA), satisfactory reproducibility (RSDs in one day and between days were both less than 5%) and reliability, and is well suitable to the quantification of the circulating DNA in human serum or plasma.
In this paper, we first presented a novel method for quantification of circulating DNA in human serum based on capillary zone electrophoresis with laser-induced fluorescence detection (CZE-LIF). The serum was digested by proteinase to release free DNA, and then CZE-LIF system was used for the quantification of total circulating DNA. This method was successfully used to quantify the circulating DNA levels in sera from healthy individuals and certain cancer patients. We found the significantly elevated circulating DNA levels in certain prostate cancer patients. Our results demonstrated that CZE-LIF system has good linearity, excellent sensitivity (0.5 ng/mL DNA), satisfactory reproducibility (RSDs in one day and between days were both less than 5%) and reliability, and is well suitable to the quantification of the circulating DNA in human serum or plasma.
2004, 15(9): 1095-1097
Abstract:
The capability of the synthesized heteropoly complexes of rare earths {K10[(O39W11Si) Ln(Gly)3Ln(SiW11O39)]·9H2O (Ln=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy)} as the catalyst promoter in the synthesis of the ethyl acetate was studied. The results showed that the quantity of H2SO4 used for synthesizing the ethyl acetate can be reduced by 75% and the yield reached 98% at the optional condition.
The capability of the synthesized heteropoly complexes of rare earths {K10[(O39W11Si) Ln(Gly)3Ln(SiW11O39)]·9H2O (Ln=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy)} as the catalyst promoter in the synthesis of the ethyl acetate was studied. The results showed that the quantity of H2SO4 used for synthesizing the ethyl acetate can be reduced by 75% and the yield reached 98% at the optional condition.
2004, 15(9): 1098-1100
Abstract:
Ionic liquid like 1-ethyl-3-methylimidazolium bromine ([EMIM]Br) has been used as electrolyte for the electropolymerization of O-phenylenediamine at glassy carbon electrode by cyclic voltammetry. It is found that poly (O-phenylenediamine) film modified electrode has favorable electrochemical activity in acid solution.
Ionic liquid like 1-ethyl-3-methylimidazolium bromine ([EMIM]Br) has been used as electrolyte for the electropolymerization of O-phenylenediamine at glassy carbon electrode by cyclic voltammetry. It is found that poly (O-phenylenediamine) film modified electrode has favorable electrochemical activity in acid solution.
2004, 15(9): 1101-1104
Abstract:
Stable and transparent aminosilicone oil microemulsion of the average particle size below 0.05 micron was prepared. The interaction of the aminosilicone oil, water, complex surfactants and cosurfactant was studied by part pseudoternary phase diagram. The effect of cosurfactants (such as alcohol) and the mechanism of its effect on the phase behaviour of the pseudoternary system were investigated.
Stable and transparent aminosilicone oil microemulsion of the average particle size below 0.05 micron was prepared. The interaction of the aminosilicone oil, water, complex surfactants and cosurfactant was studied by part pseudoternary phase diagram. The effect of cosurfactants (such as alcohol) and the mechanism of its effect on the phase behaviour of the pseudoternary system were investigated.
2004, 15(9): 1105-1108
Abstract:
Two new Schiff base complexes,[NiL]ClO4 1 and [CuL]ClO4·0.5H2O 2, were synthesized and characterized, where L is the 1:1 condensation product of salicylaldehyde and diethylenetriamine. Their crystal structures and magnetic properties were determined and investigated. The H-bonding interactions concern just in neighbor cation and anion, do not extend into network for both 1 and 2. The temperature dependence of the magnetic susceptibilities (2-300K) showed that 1 is diamagnetism and 2 is paramagnetism with weak antiferromagnetic exchange interactions between adjacent spin carriers, no magnetic ordering taking place in these two complexes.
Two new Schiff base complexes,[NiL]ClO4 1 and [CuL]ClO4·0.5H2O 2, were synthesized and characterized, where L is the 1:1 condensation product of salicylaldehyde and diethylenetriamine. Their crystal structures and magnetic properties were determined and investigated. The H-bonding interactions concern just in neighbor cation and anion, do not extend into network for both 1 and 2. The temperature dependence of the magnetic susceptibilities (2-300K) showed that 1 is diamagnetism and 2 is paramagnetism with weak antiferromagnetic exchange interactions between adjacent spin carriers, no magnetic ordering taking place in these two complexes.
2004, 15(9): 1109-1112
Abstract:
Poly (N-vinylacetamide) (PNVA) was synthesized by the free radical polymerization and its samarium (Ⅲ) binary complex was prepared and characterized by means of IR, UV-vis, X-ray photoelectron spectroscopy (XPS) and fluorescence spectra. The fluorescent intensity of samarium (Ⅲ) characteristic emission was increased significantly due to efficient energy transfer from polymeric ligand to Sm (Ⅲ) ion in the complex.
Poly (N-vinylacetamide) (PNVA) was synthesized by the free radical polymerization and its samarium (Ⅲ) binary complex was prepared and characterized by means of IR, UV-vis, X-ray photoelectron spectroscopy (XPS) and fluorescence spectra. The fluorescent intensity of samarium (Ⅲ) characteristic emission was increased significantly due to efficient energy transfer from polymeric ligand to Sm (Ⅲ) ion in the complex.
2004, 15(9): 1113-1116
Abstract:
Highly oriented ZnO nanotube array films on the conducting substrates have been synthesized by a simple hydrothermal method and characterized by scanning electron microscopy (SEM) and UV-Vis spectroscopy. The thin films consisting of laterally fragmentized ZnO nanotubes with controlled orientation have been tested as photoanode in Gr?tzel-type solar cell. For a sandwich-type cell, with 0.5 mol/L LiI and 0.05 mol/L I2 in propylene carbonate electrolyte, the overall solar energy conversion efficiency reaches 2.3%.
Highly oriented ZnO nanotube array films on the conducting substrates have been synthesized by a simple hydrothermal method and characterized by scanning electron microscopy (SEM) and UV-Vis spectroscopy. The thin films consisting of laterally fragmentized ZnO nanotubes with controlled orientation have been tested as photoanode in Gr?tzel-type solar cell. For a sandwich-type cell, with 0.5 mol/L LiI and 0.05 mol/L I2 in propylene carbonate electrolyte, the overall solar energy conversion efficiency reaches 2.3%.
2004, 15(9): 1117-1119
Abstract:
A new class of non-covalent charge-transfer complex for anion sensing, consisting of di(hydroxymethyl) di-(2-pyrrolyl) methane and chloranil (TCBQ) is characterized. The new colorimetric anion sensors can generate visual color change against PO43- and HPO42- anions in EtOH/H2O (1:1 v/v) mixture solution. The dipyrromethane-quinone aggregations may be used for higher selective detection of PO43- than other inorganic anions in water solution.
A new class of non-covalent charge-transfer complex for anion sensing, consisting of di(hydroxymethyl) di-(2-pyrrolyl) methane and chloranil (TCBQ) is characterized. The new colorimetric anion sensors can generate visual color change against PO43- and HPO42- anions in EtOH/H2O (1:1 v/v) mixture solution. The dipyrromethane-quinone aggregations may be used for higher selective detection of PO43- than other inorganic anions in water solution.
2004, 15(9): 1120-1122
Abstract:
High quality A-type zeolite membranes, with enlarged area over 70 cm2, were successfully synthesized on a tubular (-Al2O3 support by applying the vacuum seeding method.
High quality A-type zeolite membranes, with enlarged area over 70 cm2, were successfully synthesized on a tubular (-Al2O3 support by applying the vacuum seeding method.
2004, 15(9): 1123-1126
Abstract:
Ratio of Lewis/Brφnsted acid sites (Cl/Cb) on the surface of nano-sized HZSM-5 was successfully manipulated by means of steaming and acid leaching. Significant enhancement of the deactivation durability of nano-sized HZSM-5 in the aromatization of fluid catalytic cracking (FCC) gasoline olefins seems to be closely related to the increase of Lewis/Brφnsted acid sites ratio.
Ratio of Lewis/Brφnsted acid sites (Cl/Cb) on the surface of nano-sized HZSM-5 was successfully manipulated by means of steaming and acid leaching. Significant enhancement of the deactivation durability of nano-sized HZSM-5 in the aromatization of fluid catalytic cracking (FCC) gasoline olefins seems to be closely related to the increase of Lewis/Brφnsted acid sites ratio.
2004, 15(9): 1127-1130
Abstract:
The sol-gel technology is applied for the preparation of solid-phase microextraction (SPME) fiber. The fiber demonstrates high thermal stability, efficient extraction rate and the selectivity for non-polar or low-polar analytes. Efficient SPME-GC-FID analyses of benzene-toluene-ethylbenzene-xylenes (BTEXs) and low-polar halocarbon were achieved by the sol-gel coated DSDA-DDBT-TiO2 fiber. Some parameters of the SPME fiber for the determination of halocarbon in aqueous sample were investigated.
The sol-gel technology is applied for the preparation of solid-phase microextraction (SPME) fiber. The fiber demonstrates high thermal stability, efficient extraction rate and the selectivity for non-polar or low-polar analytes. Efficient SPME-GC-FID analyses of benzene-toluene-ethylbenzene-xylenes (BTEXs) and low-polar halocarbon were achieved by the sol-gel coated DSDA-DDBT-TiO2 fiber. Some parameters of the SPME fiber for the determination of halocarbon in aqueous sample were investigated.
2004, 15(9): 1131-1134
Abstract:
In this paper, photoinduced electron transfer(PET) phosphoroionophore, N-(1-bromo-2-naphthylmethyl)-diethanolamine (BND) was synthesized and its phosphorescent characteristics were studied. The experimental results showed that strong phosphorescence could be observed in β-cyclodextrin aqueous solution only at low pH value. This system combined AND and NOT function to produce a three-input inhibit (INH) logic gate.
In this paper, photoinduced electron transfer(PET) phosphoroionophore, N-(1-bromo-2-naphthylmethyl)-diethanolamine (BND) was synthesized and its phosphorescent characteristics were studied. The experimental results showed that strong phosphorescence could be observed in β-cyclodextrin aqueous solution only at low pH value. This system combined AND and NOT function to produce a three-input inhibit (INH) logic gate.
