The widespread use of herbicides such as glyphosate isopropyl amine salt(GIS)and atrazine(ATZ)poses significant risks to aquatic ecosystems.This study investigated the single and joint acute toxicity of a 1:1 GIS-ATZ ...The widespread use of herbicides such as glyphosate isopropyl amine salt(GIS)and atrazine(ATZ)poses significant risks to aquatic ecosystems.This study investigated the single and joint acute toxicity of a 1:1 GIS-ATZ mixture on zebrafish(Danio rerio).Acute tests determined 96-h LC_(50) values of 123.41 mg/L for GIS and 103.95 mg/L for ATZ.In the joint toxicity test,these values decreased to 60.96 and 50.88 mg/L,respectively.The Additive Index(AI)analysis revealed a consistent synergistic interaction between the herbicides at all exposure intervals.These findings underscore the enhanced ecological threat of herbicide mixtures and highlight the necessity of considering joint effects in environmental risk assessments.展开更多
The phototransformation of the herbicide Isopropyl carbanilate (IPC) has been investigated under UV light. Irradiation of the herbicide at room temperature in aqueous and organic solvents such as hexane and methanol a...The phototransformation of the herbicide Isopropyl carbanilate (IPC) has been investigated under UV light. Irradiation of the herbicide at room temperature in aqueous and organic solvents such as hexane and methanol afforded new photo-products formed as a consequence of various processes including photo-Fries rearrangement, ring solvolysis, hydrolysis of the amide/carbamoyl and ester bonds, ring coupling and polymerization. The percentage remaining of the herbicide as a function of time was followed periodically starting from zero time up to three hours. Analyses were performed by GC-FID equipped with a semipolar glass column operated at 170?C. The rate of photo disappearance of IPC under controlled lab condition followed 1st order kinetics and found to be solvent dependent in the manner of non polar > polar solvents. The photo-products were successfully separated by GC and preparative TLC (Silica gel F-254) and were identified using either GC-MS and/or MS. Identifications were assigned on the bases of molecular ions, mass fragmentation pattern and whenever possible by comparison with the mass spectra of literature analogues.展开更多
The isobaric vapor-liquid equilibrium data of systems of ethyl acetate<sub>（1）</sub>-n-octane<sub>（2）</sub> andisopropyl acetate<sub>（1）</sub>-n-octane<sub>（2）</sub...The isobaric vapor-liquid equilibrium data of systems of ethyl acetate<sub>（1）</sub>-n-octane<sub>（2）</sub> andisopropyl acetate<sub>（1）</sub>-n-octane<sub>（2）</sub> were determined at 0.0709 MPa and 0.1013 MPa by using a modifiedRose-Williams still.The experimental data were tested for thermodynamical consistency and correlatedsatisfactorily with p-T equation of state and Wilson equation.展开更多
ZrO2-MnO2-ZnO supports were prepared by the co-precipitation method,and then Ni-Na/ZrO2-MnO2-ZnO catalysts were prepared by the impregnation method.In this paper,the reactions to synthesize methyl isopropyl ketone and...ZrO2-MnO2-ZnO supports were prepared by the co-precipitation method,and then Ni-Na/ZrO2-MnO2-ZnO catalysts were prepared by the impregnation method.In this paper,the reactions to synthesize methyl isopropyl ketone and diethyl ketone by the one-step synthesis method over this catalyst were studied,and meanwhile,the impact of the catalyst preparation conditions and the reaction conditions on catalyst performance was also investigated.It was observed that under the conditions when Ni loading was 25%,calcination temperature was 400℃ and reduction temperature was 410℃,this catalyst had good catalytic performance on the reaction.The suitable reaction conditions were achieved:reaction temperature was 400℃;reaction at atmospheric pressure;liquid hourly space velocity of raw material of 0.5 h 1 ;and the molar ratio of(methanol)/(methyl ethyl ketone)/(water) was equal to 1/1/1.Under such conditions,the conversion of methyl ethyl ketone could achieve 41.7%,and the overall selectivity of methyl isopropyl ketone and diethyl ketone could achieve 83.3%,which was comparable to the conversion of 38.1% and the selectivity of 82.2% achieved by using palladium as the active material.The good stability made this catalyst have good prospects for industrial application.展开更多
In this paper, 2-isopropyl naphthalene has been synthesized by the reaction of naphthalene and isopropyl bromide, using triethylamine hydrochloride-aluminum chloride ionic liquid as the catalyst. The effect of the cat...In this paper, 2-isopropyl naphthalene has been synthesized by the reaction of naphthalene and isopropyl bromide, using triethylamine hydrochloride-aluminum chloride ionic liquid as the catalyst. The effect of the catalyst composition, the reaction time, the reaction temperature, the ionic liquid dosage, as well as the molar ratio of the reagents on the 2-isopropyl naphthalene yield was systematically investigated. The optimal reaction conditions cover: an AlCl3 to Et3NHCl ratio of 2.0, a reaction time of 3 h, a reaction temperature of 15.0 ℃, a volume fraction of ionic liquid to the mixture(isopropyl bromide, n-dodecane and n-hexane) of 9%, and a naphthalene/isopropyl bromide molar ratio of 4.0. Under the optimal reaction conditions, the conversion of isopropyl bromide reached 98% and the selectivity of 2-isopropyl naphthalene was equal to 80%. The test results verified good catalytic activity upon using Et3NHCl-AlCl3 ionic liquid as the catalyst for alkylation of naphthalene with isopropyl bromide. The activity of the ionic liquid remains unchanged after it has been recycled for 4 times.展开更多
An efficient synthesis of benzoin isopropyl ether with benzaldehyde and propanol in the presence of heterogeneous recyclable Cu-Fe-hydrotalcite catalyst has been explored.Cu-Fe-hydrotalcite was firstly successfully sy...An efficient synthesis of benzoin isopropyl ether with benzaldehyde and propanol in the presence of heterogeneous recyclable Cu-Fe-hydrotalcite catalyst has been explored.Cu-Fe-hydrotalcite was firstly successfully synthesized over Jahn-Teller effect of Cu^2+.The catalytic test result showed that Cu-Fe-hydrotalcite could be used as a good catalyst in the synthesis of benzoin isopropyl ether.The highest conversion of ben-zaldehyde was 59.7%and the selectivity of benzoin isopropyl ether was nearly 100%.By this new method,not only was the cyanide poisoning avoided,but also the synthesis of benzoin isopropyl ether could be completed in one step instead of traditional two steps with both condensation and etherification.展开更多
Based on Hall et al. electrotopological state indices（EK） of atom types, two quantitative structure-activity relationship（QSAR） models were developed to estimate and predict the action strength（W） of D（OM）（di...Based on Hall et al. electrotopological state indices（EK） of atom types, two quantitative structure-activity relationship（QSAR） models were developed to estimate and predict the action strength（W） of D（OM）（dimethoxy-methyl-amphetamine） for 18 phenyl-isopropyl-amine dopes（PPAD） through linear method（multiple linear regression, MLR） and non-linear method（Back propagation artificial neural network, BP-ANN）. On the basis of EK, the optimal three-parameter（E14, E9, E7） QSAR model of W for 18 PPAD was constructed. The traditional correlation coefficient（R^2） and cross-validation correlation coefficient（Rcv^2） are 0.878 and 0.815, respectively. The result demonstrates that the model is highly reliable（from the point of view of statistics） and has good predictive ability by using R^2, Rcv^2, VIF, FIT, AIC and F tests. Form the three parameters of the model, it is known that the dominant influence factors of inhibited activity are the molecular structure fragments： =CH–（secondary carbon）, =C〈（tertiary carbon atom） in aromatic ring and –O–（phenol ether bond）. The results showed that the structure parameters E14, E9 and E7 have good rationality and efficiency for the W of phenyl-isopropyl-amine dope（PPAD） analogues. A BP-ANN with 3-3-1 architecture was generated by using three electrotopological state index descriptors（E14, E9, E7） appearing in the MLR model, the above descriptors were inputs and its output was action strength（W）. The nonlinear BP-ANN model has better predictive ability compared to the linear MLR model with R^2 and Rcv^2 of leave-one-out（LOO） to be 0.995 and 0.994, respectively. The regression method gave support to the neural network with physical explanation, which offers a more accurate model for QSAR. Those models can be used in the rational design of higher stimulating extent PPAD, which provide meaningful reference information to improve the detection methods of PPAD.展开更多
Super acid catalyst SO4^2-/ZrO2 was introduced into pure silicone MCM-41 via the impregnation method and the catalyst samples obtained at different temperatures were characterized by means of XRD, IR, and Py-IR techni...Super acid catalyst SO4^2-/ZrO2 was introduced into pure silicone MCM-41 via the impregnation method and the catalyst samples obtained at different temperatures were characterized by means of XRD, IR, and Py-IR techniques. The selectively catalytic gas-phase flow reactions of benzene with propene over the catalyst samples were carried out in a made-to-measure high-pressure flow reactor equipped with a thermostat and a condenser. Effect of the preparative condition on the catalytic synthesis of isopropyl benzene over the catalyst samples was tested. The results show that SO4^2-/ZrO2-MCM-41 （ SZM-41 ） can be used as a catalyst for the title reaction, in which there are a higher conversion （97%） for the propene and a higher selectivity（93% ） for the isopropyl benzene.展开更多
Mono(isopropyl maleate-oyloxyl) diisopropoxyl dysprosium(DM) was synthesized by the reaction of dysprosium isopropoxide with maleic anhydride. Dy-containing polymer(PDM) was obtained by the solution polymerization of ...Mono(isopropyl maleate-oyloxyl) diisopropoxyl dysprosium(DM) was synthesized by the reaction of dysprosium isopropoxide with maleic anhydride. Dy-containing polymer(PDM) was obtained by the solution polymerization of DM using 2, 2'-azobisisobutyronitrile (AIBN) as an initiator. The kinetic study on the polymerization shows that the polymerization of DM exhibits high apparent activation energy(96.3 kJ.mol(-1)), indicating that the activity of DM is low for polymerization. The kinetic equation of polymerization can be expressed as R-P = k(P)C(DM)(1.23)c(AIBN)(0.82). The polymeric solid material shows excellent heat-stability and strong characteristic fluorescence of Dy3+, (4)Fg(9/2) --> H-6(15/2) and F-4(9/2) --> H-6(13/2).展开更多
The extraction and stripping of scandium from its sulfate solutions by isopropyl phosphonic acid mono (1-hexyl-4-ethyl) octyl ester (PT-2, HL) diluted with n-hexane are reported. A high efficiency of separation betwee...The extraction and stripping of scandium from its sulfate solutions by isopropyl phosphonic acid mono (1-hexyl-4-ethyl) octyl ester (PT-2, HL) diluted with n-hexane are reported. A high efficiency of separation between scandium, iron and lutetium can be achieved by controlling aqueous acidity. Different mechanisms of Sc3+ with PT-2 in various acid range have been proposed.At lower aqueous acidity, it is a cation exchange reaction, while at higher acidity. a solvation reaction was ascertained. Its IR and NMR spectra have been discussed. The effect of temperature on extraction of Sc3+ was observed and thermodynamic functions were calculated.展开更多
In this study, the kinetics of isopropyl palmitate synthesis including the reaction mechanism was studied based on the two-step noncatalytic method. The liquid-phase diffusion effect on the reaction process was elimin...In this study, the kinetics of isopropyl palmitate synthesis including the reaction mechanism was studied based on the two-step noncatalytic method. The liquid-phase diffusion effect on the reaction process was eliminated by adjusting the stirring rate. The results showed that the two-step reaction followed a tetrahedral mechanism and conformed to second-order reaction kinetics. Nucleophilic attack on the carbonyl carbon afforded an intermediate, containing a tetrahedral carbon center. The intermediate ultimately decomposed by elimination of the leaving group, affording isopropyl palmitate. The experimental data were analyzed at different temperatures by the integral method. The kinetic equations of the each step were deduced, and the activation energy and frequency factor were obtained. Experiments were performed to verify the feasibility of kinetic equations, and the result showed that the kinetic equations were reliable. This study could be very signi ficant to both industrial application and determining the continuous production of isopropyl palmitate.展开更多
Thermal and salt dual stimuli-responsive filter-paper-based membranes were prepared by UV-induced grafting of NIPAM-based polymers on paper surface. The grafting ratio could be controlled by monomer concentration duri...Thermal and salt dual stimuli-responsive filter-paper-based membranes were prepared by UV-induced grafting of NIPAM-based polymers on paper surface. The grafting ratio could be controlled by monomer concentration during grafting polymerization. The results from pressure drop measurement of the mobile phase flowed cross the membrane demonstrate that an appropriate grafting ratio would be 8%-10%. Protein adsorption on the membrane through hydrophobic interaction could be promoted by increasing temperature and lyotropic salt concentration. The effect of grafted polymer structure on protein binding performance was studied. Filter paper grafted with NIPAM-based branched copolymer consisting of hydrophobic monomer moieties shows ten times higher protein binding capacity than that of the original filter paper. The separation of plasma proteins using the dual stimuli-responsive membrane was examined to demonstrate feasible application for hydrophobic interaction chromatographic separation of proteins.展开更多
The thermo- and pH-responsive hydrogels were synthesized via copolymerization of N-isopropylacrylamide and al-lylamine hydrochloride monomers. The equilibrium swelling of the hydrogels was studied as a function of tem...The thermo- and pH-responsive hydrogels were synthesized via copolymerization of N-isopropylacrylamide and al-lylamine hydrochloride monomers. The equilibrium swelling of the hydrogels was studied as a function of temperature and pH in aqueous solutions. It was shown that controlled alteration of the hydrogel phase transition temperature can be achieved by changing their composition and pH of the environment. Increase in content of hydrophilic allylamine from 10 to 60 wt% in monomer mixture causes a shift of the phase transition temperature from 35oC to 47oC. Hydrogels with N-isopropylacrylamide/allylamine hydrochloride mass ratio of 3:2 show the highest pH-response. Values of average molecular weight between polymer cross-links, , and Flory parameter, χ, were calculated using temperature dependences of the equilibrium swelling of the synthesized hydrogel.展开更多
Isopropyl alcohol matrix effect was found to be element specific by using the defined matrix effect factor in ICP-MS, which could not be corrected by using the conventional internal reference method. Unlike the conven...Isopropyl alcohol matrix effect was found to be element specific by using the defined matrix effect factor in ICP-MS, which could not be corrected by using the conventional internal reference method. Unlike the conventional internal reference method, the presented method allows for the analyte to behave differently from the internal reference under the influence of the matrix.展开更多
A new method of indirect determination of ascorbic acid(Vc) with ammonium sulfate and isopropyl alcohol by extraction-flotation of copper is studied in this paper. It shows that a small amount of Cu(Ⅱ) can be reduced...A new method of indirect determination of ascorbic acid(Vc) with ammonium sulfate and isopropyl alcohol by extraction-flotation of copper is studied in this paper. It shows that a small amount of Cu(Ⅱ) can be reduced to Cu( Ⅰ ) by Vc, then Cu(Ⅰ) reacted with the SCN-, which precipitated on the interface of isopropyl alcohol and H2O. A good linear relationship is observed between the flotation yield(E) of Cu( Ⅱ) and the amount of Vc. The detection limit for Vc is 1.76μg/mL. The method is simple, rapid (5 min), but suffers from little interference of common anions and cations. It has been successfully applied for the determination of Vc in fruits.展开更多
Photocatalytic reduction of CO2 was carried out on villiform spherical catalysts of Pd-TiO2 in isopropanol solution.The catalysts were synthesized by hydrothermal method,their structures,morphologies and optical absor...Photocatalytic reduction of CO2 was carried out on villiform spherical catalysts of Pd-TiO2 in isopropanol solution.The catalysts were synthesized by hydrothermal method,their structures,morphologies and optical absorption properties were characterized by X-ray diffraction（XRD）,energy dispersive X-ray spectroscopy（EDS）,scanning electron microscopy（SEM）,transmission electron microscopy（TEM）,highresolution transmission electron microscopy（HRTEM）and UV-vis absorption spectroscopy（UV-vis）.The photocatalytic activities with different loading amounts and morphologies were evaluated for determining the dominant effect and optimizing the catalyst preparation.Based on a villiform spherical TiO2 with the largest specific surface area in our experiments,we prepared a set of catalysts with various loading amounts of palladium and tested them by bubbling CO2 through the slurry of catalyst and isopropanol.The highest formation rate of isopropyl formate was 276.6μmol/g？cat/h.Eventually we proposed the reaction mechanism.展开更多
A new phosphorylating reagent, N,N-di-isopropyl-O,O-di-p-methoxybenzylphosphoramidite was synthesized from diisopropylamino dichlorophosphine and p-methoxybenzyl alcohol for preparing phosphatydyl inositol polyphospha...A new phosphorylating reagent, N,N-di-isopropyl-O,O-di-p-methoxybenzylphosphoramidite was synthesized from diisopropylamino dichlorophosphine and p-methoxybenzyl alcohol for preparing phosphatydyl inositol polyphosphate particularly with unsaturated components.展开更多
The key intermediate, 2-isopropyl-2-(3-methyl-1-benzoxyl-5-phenylsulfonyl-3E-pentenyl)-1, 3-dithiocycllohexane(Ⅲ), for the total synthesis of Sarcophytol-A (1)was prepared through 7 steps from acetone. The key steps ...The key intermediate, 2-isopropyl-2-(3-methyl-1-benzoxyl-5-phenylsulfonyl-3E-pentenyl)-1, 3-dithiocycllohexane(Ⅲ), for the total synthesis of Sarcophytol-A (1)was prepared through 7 steps from acetone. The key steps are nucleophilic addition of 2-1ithio-2-isopropyl-1,3-dithiocyclohexane to aldehyde 5 and double bond migration reaction of allylic alcohol 9 and 10.展开更多
Chiral 4-[(2-isopropyl-5-methylcyclohexyl)oxo]-4-oxobutanoic acid reacts with substituted anilines to produce amides 1-6 in high yields. Resulted amides 1-6 were investigated for their antifungal and antibacterial act...Chiral 4-[(2-isopropyl-5-methylcyclohexyl)oxo]-4-oxobutanoic acid reacts with substituted anilines to produce amides 1-6 in high yields. Resulted amides 1-6 were investigated for their antifungal and antibacterial activities. Compounds 2 (96.5%) against Aspergillus fumigatus and 6 (93.7%) against Helminthosporium sativum demonstrated excellent activities. However, compounds 3 (37.6%) against Bacillus subtilis, 4 (33.2%) against Pseudomonas aurignosa, 5 against Klebsiella pneumonia demonstrated excellent growth inhibition potential.展开更多
基金Supported by The Central Public-Interest Scientific Institution Basal Research Fund,CAFS(2025XT0902)Earmarked for China Agriculture Research System(CARS-46).
文摘The widespread use of herbicides such as glyphosate isopropyl amine salt(GIS)and atrazine(ATZ)poses significant risks to aquatic ecosystems.This study investigated the single and joint acute toxicity of a 1:1 GIS-ATZ mixture on zebrafish(Danio rerio).Acute tests determined 96-h LC_(50) values of 123.41 mg/L for GIS and 103.95 mg/L for ATZ.In the joint toxicity test,these values decreased to 60.96 and 50.88 mg/L,respectively.The Additive Index(AI)analysis revealed a consistent synergistic interaction between the herbicides at all exposure intervals.These findings underscore the enhanced ecological threat of herbicide mixtures and highlight the necessity of considering joint effects in environmental risk assessments.
文摘The phototransformation of the herbicide Isopropyl carbanilate (IPC) has been investigated under UV light. Irradiation of the herbicide at room temperature in aqueous and organic solvents such as hexane and methanol afforded new photo-products formed as a consequence of various processes including photo-Fries rearrangement, ring solvolysis, hydrolysis of the amide/carbamoyl and ester bonds, ring coupling and polymerization. The percentage remaining of the herbicide as a function of time was followed periodically starting from zero time up to three hours. Analyses were performed by GC-FID equipped with a semipolar glass column operated at 170?C. The rate of photo disappearance of IPC under controlled lab condition followed 1st order kinetics and found to be solvent dependent in the manner of non polar > polar solvents. The photo-products were successfully separated by GC and preparative TLC (Silica gel F-254) and were identified using either GC-MS and/or MS. Identifications were assigned on the bases of molecular ions, mass fragmentation pattern and whenever possible by comparison with the mass spectra of literature analogues.
文摘The isobaric vapor-liquid equilibrium data of systems of ethyl acetate<sub>（1）</sub>-n-octane<sub>（2）</sub> andisopropyl acetate<sub>（1）</sub>-n-octane<sub>（2）</sub> were determined at 0.0709 MPa and 0.1013 MPa by using a modifiedRose-Williams still.The experimental data were tested for thermodynamical consistency and correlatedsatisfactorily with p-T equation of state and Wilson equation.
基金Supported by the National Science and Technology Support Program Project (2006BAE03B06)
文摘ZrO2-MnO2-ZnO supports were prepared by the co-precipitation method,and then Ni-Na/ZrO2-MnO2-ZnO catalysts were prepared by the impregnation method.In this paper,the reactions to synthesize methyl isopropyl ketone and diethyl ketone by the one-step synthesis method over this catalyst were studied,and meanwhile,the impact of the catalyst preparation conditions and the reaction conditions on catalyst performance was also investigated.It was observed that under the conditions when Ni loading was 25%,calcination temperature was 400℃ and reduction temperature was 410℃,this catalyst had good catalytic performance on the reaction.The suitable reaction conditions were achieved:reaction temperature was 400℃;reaction at atmospheric pressure;liquid hourly space velocity of raw material of 0.5 h 1 ;and the molar ratio of(methanol)/(methyl ethyl ketone)/(water) was equal to 1/1/1.Under such conditions,the conversion of methyl ethyl ketone could achieve 41.7%,and the overall selectivity of methyl isopropyl ketone and diethyl ketone could achieve 83.3%,which was comparable to the conversion of 38.1% and the selectivity of 82.2% achieved by using palladium as the active material.The good stability made this catalyst have good prospects for industrial application.
基金financially supported by the National Natural Science Foundation of China (No. 21205086)
文摘In this paper, 2-isopropyl naphthalene has been synthesized by the reaction of naphthalene and isopropyl bromide, using triethylamine hydrochloride-aluminum chloride ionic liquid as the catalyst. The effect of the catalyst composition, the reaction time, the reaction temperature, the ionic liquid dosage, as well as the molar ratio of the reagents on the 2-isopropyl naphthalene yield was systematically investigated. The optimal reaction conditions cover: an AlCl3 to Et3NHCl ratio of 2.0, a reaction time of 3 h, a reaction temperature of 15.0 ℃, a volume fraction of ionic liquid to the mixture(isopropyl bromide, n-dodecane and n-hexane) of 9%, and a naphthalene/isopropyl bromide molar ratio of 4.0. Under the optimal reaction conditions, the conversion of isopropyl bromide reached 98% and the selectivity of 2-isopropyl naphthalene was equal to 80%. The test results verified good catalytic activity upon using Et3NHCl-AlCl3 ionic liquid as the catalyst for alkylation of naphthalene with isopropyl bromide. The activity of the ionic liquid remains unchanged after it has been recycled for 4 times.
基金support from the National Natural Science Foundation of China(50872086)the Natural Science Foundation of Shanxi Province(2008011018)
文摘An efficient synthesis of benzoin isopropyl ether with benzaldehyde and propanol in the presence of heterogeneous recyclable Cu-Fe-hydrotalcite catalyst has been explored.Cu-Fe-hydrotalcite was firstly successfully synthesized over Jahn-Teller effect of Cu^2+.The catalytic test result showed that Cu-Fe-hydrotalcite could be used as a good catalyst in the synthesis of benzoin isopropyl ether.The highest conversion of ben-zaldehyde was 59.7%and the selectivity of benzoin isopropyl ether was nearly 100%.By this new method,not only was the cyanide poisoning avoided,but also the synthesis of benzoin isopropyl ether could be completed in one step instead of traditional two steps with both condensation and etherification.
基金supported by the National Natural Science Foundation of China(21075138)special fund of State Key Laboratory of Structural Chemistry(20160003)
文摘Based on Hall et al. electrotopological state indices（EK） of atom types, two quantitative structure-activity relationship（QSAR） models were developed to estimate and predict the action strength（W） of D（OM）（dimethoxy-methyl-amphetamine） for 18 phenyl-isopropyl-amine dopes（PPAD） through linear method（multiple linear regression, MLR） and non-linear method（Back propagation artificial neural network, BP-ANN）. On the basis of EK, the optimal three-parameter（E14, E9, E7） QSAR model of W for 18 PPAD was constructed. The traditional correlation coefficient（R^2） and cross-validation correlation coefficient（Rcv^2） are 0.878 and 0.815, respectively. The result demonstrates that the model is highly reliable（from the point of view of statistics） and has good predictive ability by using R^2, Rcv^2, VIF, FIT, AIC and F tests. Form the three parameters of the model, it is known that the dominant influence factors of inhibited activity are the molecular structure fragments： =CH–（secondary carbon）, =C〈（tertiary carbon atom） in aromatic ring and –O–（phenol ether bond）. The results showed that the structure parameters E14, E9 and E7 have good rationality and efficiency for the W of phenyl-isopropyl-amine dope（PPAD） analogues. A BP-ANN with 3-3-1 architecture was generated by using three electrotopological state index descriptors（E14, E9, E7） appearing in the MLR model, the above descriptors were inputs and its output was action strength（W）. The nonlinear BP-ANN model has better predictive ability compared to the linear MLR model with R^2 and Rcv^2 of leave-one-out（LOO） to be 0.995 and 0.994, respectively. The regression method gave support to the neural network with physical explanation, which offers a more accurate model for QSAR. Those models can be used in the rational design of higher stimulating extent PPAD, which provide meaningful reference information to improve the detection methods of PPAD.
文摘Super acid catalyst SO4^2-/ZrO2 was introduced into pure silicone MCM-41 via the impregnation method and the catalyst samples obtained at different temperatures were characterized by means of XRD, IR, and Py-IR techniques. The selectively catalytic gas-phase flow reactions of benzene with propene over the catalyst samples were carried out in a made-to-measure high-pressure flow reactor equipped with a thermostat and a condenser. Effect of the preparative condition on the catalytic synthesis of isopropyl benzene over the catalyst samples was tested. The results show that SO4^2-/ZrO2-MCM-41 （ SZM-41 ） can be used as a catalyst for the title reaction, in which there are a higher conversion （97%） for the propene and a higher selectivity（93% ） for the isopropyl benzene.
文摘Mono(isopropyl maleate-oyloxyl) diisopropoxyl dysprosium(DM) was synthesized by the reaction of dysprosium isopropoxide with maleic anhydride. Dy-containing polymer(PDM) was obtained by the solution polymerization of DM using 2, 2'-azobisisobutyronitrile (AIBN) as an initiator. The kinetic study on the polymerization shows that the polymerization of DM exhibits high apparent activation energy(96.3 kJ.mol(-1)), indicating that the activity of DM is low for polymerization. The kinetic equation of polymerization can be expressed as R-P = k(P)C(DM)(1.23)c(AIBN)(0.82). The polymeric solid material shows excellent heat-stability and strong characteristic fluorescence of Dy3+, (4)Fg(9/2) --> H-6(15/2) and F-4(9/2) --> H-6(13/2).
文摘The extraction and stripping of scandium from its sulfate solutions by isopropyl phosphonic acid mono (1-hexyl-4-ethyl) octyl ester (PT-2, HL) diluted with n-hexane are reported. A high efficiency of separation between scandium, iron and lutetium can be achieved by controlling aqueous acidity. Different mechanisms of Sc3+ with PT-2 in various acid range have been proposed.At lower aqueous acidity, it is a cation exchange reaction, while at higher acidity. a solvation reaction was ascertained. Its IR and NMR spectra have been discussed. The effect of temperature on extraction of Sc3+ was observed and thermodynamic functions were calculated.
文摘In this study, the kinetics of isopropyl palmitate synthesis including the reaction mechanism was studied based on the two-step noncatalytic method. The liquid-phase diffusion effect on the reaction process was eliminated by adjusting the stirring rate. The results showed that the two-step reaction followed a tetrahedral mechanism and conformed to second-order reaction kinetics. Nucleophilic attack on the carbonyl carbon afforded an intermediate, containing a tetrahedral carbon center. The intermediate ultimately decomposed by elimination of the leaving group, affording isopropyl palmitate. The experimental data were analyzed at different temperatures by the integral method. The kinetic equations of the each step were deduced, and the activation energy and frequency factor were obtained. Experiments were performed to verify the feasibility of kinetic equations, and the result showed that the kinetic equations were reliable. This study could be very signi ficant to both industrial application and determining the continuous production of isopropyl palmitate.
基金financially supported by the China Scholarship Council and the National Natural Science Foundation of China(No.20874004)
文摘Thermal and salt dual stimuli-responsive filter-paper-based membranes were prepared by UV-induced grafting of NIPAM-based polymers on paper surface. The grafting ratio could be controlled by monomer concentration during grafting polymerization. The results from pressure drop measurement of the mobile phase flowed cross the membrane demonstrate that an appropriate grafting ratio would be 8%-10%. Protein adsorption on the membrane through hydrophobic interaction could be promoted by increasing temperature and lyotropic salt concentration. The effect of grafted polymer structure on protein binding performance was studied. Filter paper grafted with NIPAM-based branched copolymer consisting of hydrophobic monomer moieties shows ten times higher protein binding capacity than that of the original filter paper. The separation of plasma proteins using the dual stimuli-responsive membrane was examined to demonstrate feasible application for hydrophobic interaction chromatographic separation of proteins.
文摘The thermo- and pH-responsive hydrogels were synthesized via copolymerization of N-isopropylacrylamide and al-lylamine hydrochloride monomers. The equilibrium swelling of the hydrogels was studied as a function of temperature and pH in aqueous solutions. It was shown that controlled alteration of the hydrogel phase transition temperature can be achieved by changing their composition and pH of the environment. Increase in content of hydrophilic allylamine from 10 to 60 wt% in monomer mixture causes a shift of the phase transition temperature from 35oC to 47oC. Hydrogels with N-isopropylacrylamide/allylamine hydrochloride mass ratio of 3:2 show the highest pH-response. Values of average molecular weight between polymer cross-links, , and Flory parameter, χ, were calculated using temperature dependences of the equilibrium swelling of the synthesized hydrogel.
基金supported by the National Natural Science Foundation of China(Nos.40521001,40703006 and 20575061)the Chinese Ministry of Education(Nos.IRT0441 and 306021).
文摘Isopropyl alcohol matrix effect was found to be element specific by using the defined matrix effect factor in ICP-MS, which could not be corrected by using the conventional internal reference method. Unlike the conventional internal reference method, the presented method allows for the analyte to behave differently from the internal reference under the influence of the matrix.
文摘A new method of indirect determination of ascorbic acid(Vc) with ammonium sulfate and isopropyl alcohol by extraction-flotation of copper is studied in this paper. It shows that a small amount of Cu(Ⅱ) can be reduced to Cu( Ⅰ ) by Vc, then Cu(Ⅰ) reacted with the SCN-, which precipitated on the interface of isopropyl alcohol and H2O. A good linear relationship is observed between the flotation yield(E) of Cu( Ⅱ) and the amount of Vc. The detection limit for Vc is 1.76μg/mL. The method is simple, rapid (5 min), but suffers from little interference of common anions and cations. It has been successfully applied for the determination of Vc in fruits.
基金Funded by the National Natural Science Foundation of China(No.21176192 and 21776220)
文摘Photocatalytic reduction of CO2 was carried out on villiform spherical catalysts of Pd-TiO2 in isopropanol solution.The catalysts were synthesized by hydrothermal method,their structures,morphologies and optical absorption properties were characterized by X-ray diffraction（XRD）,energy dispersive X-ray spectroscopy（EDS）,scanning electron microscopy（SEM）,transmission electron microscopy（TEM）,highresolution transmission electron microscopy（HRTEM）and UV-vis absorption spectroscopy（UV-vis）.The photocatalytic activities with different loading amounts and morphologies were evaluated for determining the dominant effect and optimizing the catalyst preparation.Based on a villiform spherical TiO2 with the largest specific surface area in our experiments,we prepared a set of catalysts with various loading amounts of palladium and tested them by bubbling CO2 through the slurry of catalyst and isopropanol.The highest formation rate of isopropyl formate was 276.6μmol/g？cat/h.Eventually we proposed the reaction mechanism.
文摘A new phosphorylating reagent, N,N-di-isopropyl-O,O-di-p-methoxybenzylphosphoramidite was synthesized from diisopropylamino dichlorophosphine and p-methoxybenzyl alcohol for preparing phosphatydyl inositol polyphosphate particularly with unsaturated components.
基金Supported by the National Natural Science Foundation of China State Educational Commission Foundation of China
文摘The key intermediate, 2-isopropyl-2-(3-methyl-1-benzoxyl-5-phenylsulfonyl-3E-pentenyl)-1, 3-dithiocycllohexane(Ⅲ), for the total synthesis of Sarcophytol-A (1)was prepared through 7 steps from acetone. The key steps are nucleophilic addition of 2-1ithio-2-isopropyl-1,3-dithiocyclohexane to aldehyde 5 and double bond migration reaction of allylic alcohol 9 and 10.
文摘Chiral 4-[(2-isopropyl-5-methylcyclohexyl)oxo]-4-oxobutanoic acid reacts with substituted anilines to produce amides 1-6 in high yields. Resulted amides 1-6 were investigated for their antifungal and antibacterial activities. Compounds 2 (96.5%) against Aspergillus fumigatus and 6 (93.7%) against Helminthosporium sativum demonstrated excellent activities. However, compounds 3 (37.6%) against Bacillus subtilis, 4 (33.2%) against Pseudomonas aurignosa, 5 against Klebsiella pneumonia demonstrated excellent growth inhibition potential.
