1,4-Addition reaction of Grignard's reagent to 5-methoxy-2(5H)-furanone 1 was accomplished. which provided a new possible route for synthesizing beta -alkyl-Y-alkyloxy-Y-butyrolactone. A novel concise method of pr...1,4-Addition reaction of Grignard's reagent to 5-methoxy-2(5H)-furanone 1 was accomplished. which provided a new possible route for synthesizing beta -alkyl-Y-alkyloxy-Y-butyrolactone. A novel concise method of preparing fused heterocyclic compounds was offered by 1,3-dipolar cycloaddition reaction of silyl nitronates to 1.展开更多
This paper is one of a series of reports of theoretical researches on the mechanism of the Mannich reaction using the iminium salt as the potential Mannich reagent. According to the results of AM1 dynamic calcula...This paper is one of a series of reports of theoretical researches on the mechanism of the Mannich reaction using the iminium salt as the potential Mannich reagent. According to the results of AM1 dynamic calculations, the activation energies of key steps in conventional Mannich reactions between ammonia, formaldehyde and acetaldehyde in neutral and acidic media are 438 8 kJ/mol and 393 9 kJ/mol respectively. The activation energy of the rate controlling step of the Mannich reaction which contains the potential Mannich reagent is 274 7 kJ/mol. Therefore, it can be derived that the potential Mannich reagent can increase the rate of the reaction remarkably. The reasons for this have been discussed in terms of the orbital match and electrostatic interaction between the atoms of reactant complexes. In this paper another different conjectured mechanism of the potential Mannich reagent which can reduce the activation energy is considerably studied.展开更多
A novel palladium-catalyzed coupling reaction for the preparation of derivatives of stilbazoles was presented. A series of stilbazoles were synthesized firstly by this highly efficient method. From this reaction it wa...A novel palladium-catalyzed coupling reaction for the preparation of derivatives of stilbazoles was presented. A series of stilbazoles were synthesized firstly by this highly efficient method. From this reaction it was found that reaction solvent is one of important factors in this catalytic system.展开更多
The antitumor activity of 5 fluorouracil 1 acetic acid(HFAA) and its lanthanide complexes(La(FAA) 3, Eu(FAA) 3) were studied. The results show that HFAA, La(FAA) 3 and Eu(FAA) 3 with the concentrations of 1 0&...The antitumor activity of 5 fluorouracil 1 acetic acid(HFAA) and its lanthanide complexes(La(FAA) 3, Eu(FAA) 3) were studied. The results show that HFAA, La(FAA) 3 and Eu(FAA) 3 with the concentrations of 1 0×10 -5 ～1 0×10 -2 μg·ml -1 inhibit the colony formation of leukemia cells(L 1210 ) and the growth of transplanted tumor sarcoma 180(S 180 ), hepatic carcinoma(HEPA) and ehrlich ascites tumor(EC) as well. The maximum inhibitory rate of Eu(FAA) 3 for S 180 is 38 4%, that HFAA and La(FAA) 3 for EC are 22 4% and 43 4%, respectively. The life prolongation rate of Eu(FAA) 3 for HEPA bearing mice is as long as 284%.展开更多
Dense phase voidage can be estimated by cutting gas flow and following the rate of bed collapse. Abrupt cessation of flow is not possible when excess gas in the windbox can only discharge through the bed. The magnitud...Dense phase voidage can be estimated by cutting gas flow and following the rate of bed collapse. Abrupt cessation of flow is not possible when excess gas in the windbox can only discharge through the bed. The magnitude of this problem is examined experimentally.展开更多
This paper presents an experimental study on the radial and axial profiles of local particle velocity of flu-idized catalyst(FCC)particles in a circulating fluidized bed of 8000mm in height and 186mm in inside diamete...This paper presents an experimental study on the radial and axial profiles of local particle velocity of flu-idized catalyst(FCC)particles in a circulating fluidized bed of 8000mm in height and 186mm in inside diameterwith a Fiber-Optic Probe Laser Doppler Velocimetry.It has been found that the radial profiles of local particlevelocity are parabolic,even in the centre region and steep in the region near the bed wall,and that the length ofparticle acceleration along the bed height is longer than expected.The following formula has been recommended to correlate the 1 ocal particle velocity with dilute gas-solidflow in the bed:where a,b,c and e are functions of radial positions.展开更多
On the basis of vapor pressures, volumes of saturated vapor and liquid, both parameters "a" and "b" in Soave equation of state are treated as temperature dependent and an extended Soave equation is...On the basis of vapor pressures, volumes of saturated vapor and liquid, both parameters "a" and "b" in Soave equation of state are treated as temperature dependent and an extended Soave equation is proposed in this work. The VLE for 38 pure components including polar substances have been calculated. The comparison of calculated results with experimental data shows the prediction of liquid density is improved over Soave equation without losing the accuracy of prediction in vapor pressure and vapor density.展开更多
The crystal structure of Di-nitratobis(ethylcaprolactam)uranyl(Ⅱ) UO_2[CH_2(CH_2)_4CONC_2H_5]_2(NO_3)_2 was established by a single-crystal X-ray diffraction study.It is triclinie, space group P1, with a=7.171(2), b=...The crystal structure of Di-nitratobis(ethylcaprolactam)uranyl(Ⅱ) UO_2[CH_2(CH_2)_4CONC_2H_5]_2(NO_3)_2 was established by a single-crystal X-ray diffraction study.It is triclinie, space group P1, with a=7.171(2), b=8.655(3), c=10.182(5)A, α=78.27(3), β=70.63(3), γ=81.76(3)°, V=581.7(4)A^3, Z=l, Dc=1.94 g.cm^(-3).Final R value is 0.0218.The result reveals that uranyl ion is coordinated to six oxygen atoms, two of them are from two carbonyl groups of ethylcaprolactam and the other four are from two nitrate groups.展开更多
Mathematical model is developed to estimate hemoglobin release under hypotonic conditions at microscopic level. The phenomenon of hemoglobin (Hb) release depends on: 1) the dynamics of repeated opening of hemolytic ho...Mathematical model is developed to estimate hemoglobin release under hypotonic conditions at microscopic level. The phenomenon of hemoglobin (Hb) release depends on: 1) the dynamics of repeated opening of hemolytic holes and 2) the radial fluctuations of lipid membrane. Both processes are sensitive to the rate of ionic strength decrease within the surrounding medium. Influence of the rate of ionic strength decrease on hemoglobin release is quantified by the model parameters: 1) the specific decrease of erythrocyte radius and 2) the specific decrease of hole radius during single opening time period of hemolytic hole. The prediction of released amount of Hb influenced by the conductive mechanism is equal to 2.9 %. The prediction of total released amount of Hb influenced by the conductive and convective mechanisms is approximately equal to 4 % of the initial amount of Hb within erythrocyte.展开更多
The title complex was obtained by repeatly extracting the 0.1 mol/L HCI solution of PdCl2 with the petroleum ether in which p-CH3C6H4SC4H9 was previously dissolved at room temperature. The resulting precipitate, after...The title complex was obtained by repeatly extracting the 0.1 mol/L HCI solution of PdCl2 with the petroleum ether in which p-CH3C6H4SC4H9 was previously dissolved at room temperature. The resulting precipitate, after washed With deionized water and petroleum ether respectively,展开更多
A series of hydrogels with lower critical solution temperature (LCST) were prepared and used for the immobilization of chymotrypsin. The activities of the immobilized enzyme decrease when the temperatures are raised a...A series of hydrogels with lower critical solution temperature (LCST) were prepared and used for the immobilization of chymotrypsin. The activities of the immobilized enzyme decrease when the temperatures are raised above their LCST and recover below their LCST. This property is reversible.展开更多
The surface pressure—area isotherms(π—A curves) of 2—heptadecyl imidazole (HIM) Langmuir films at the subphases of deionized water and solutions containing metal ions such as Cu^(2+), Cd^(2+), Ca^(2+), Co^(2+), Ag...The surface pressure—area isotherms(π—A curves) of 2—heptadecyl imidazole (HIM) Langmuir films at the subphases of deionized water and solutions containing metal ions such as Cu^(2+), Cd^(2+), Ca^(2+), Co^(2+), Ag^+ etc. have been studied. It was formed Langmuir film at the subphase containing Cu^(2+) or Ag^+ ions and its LB film was successfully deposited. The molecular and ionic total energies (E) and stabil. ity energies (△E) forming complexes were computed by CNDO/2 method. The computational results agreed with the experiments.展开更多
Kinetics of the steam reformig of n-butane,n-hexane,n-heptane,n-nonane and i-octane on Z409 catalystwere studied at atmospheric pressure by using an internal recycle gradientless reactor.The reaction temperaturewas va...Kinetics of the steam reformig of n-butane,n-hexane,n-heptane,n-nonane and i-octane on Z409 catalystwere studied at atmospheric pressure by using an internal recycle gradientless reactor.The reaction temperaturewas varied in the range of 743-853K,the steam carbon molar ratio 3-5.The experimental results showed thatthe reforming products contained no hydrocarbon other than methane.In addition,the product distributionof different n-paraffins were similar,but the product distribution of i-octane was different from that of n-paraffins.A reaction scheme for the steam reforming of paraffin has been proposed and the hyperbolic type rateequations were derived.It is clear that the obtained kinetic model could simulate the experimental results ofi-octane as well as different n-paraffins satisfactorily.展开更多
The behaviour of water soluble and monomer soluble inhibitors in the emulsion polymerization for CaseI system(e.g.vinyl acetate and vinyl chloride)has been studied.The behaviour of monomer soluble inhibitorsis shown t...The behaviour of water soluble and monomer soluble inhibitors in the emulsion polymerization for CaseI system(e.g.vinyl acetate and vinyl chloride)has been studied.The behaviour of monomer soluble inhibitorsis shown to be quite different from that observed in Case Ⅱ emulsion polymerization system.Model predictionsof the effect of these inhibitors on polymer particle nucleation and growth rate are shown to be in satisfactoryagreement with experimental results.展开更多
基金This work was supported by the NNSFC (No.29672004).
文摘1,4-Addition reaction of Grignard's reagent to 5-methoxy-2(5H)-furanone 1 was accomplished. which provided a new possible route for synthesizing beta -alkyl-Y-alkyloxy-Y-butyrolactone. A novel concise method of preparing fused heterocyclic compounds was offered by 1,3-dipolar cycloaddition reaction of silyl nitronates to 1.
文摘This paper is one of a series of reports of theoretical researches on the mechanism of the Mannich reaction using the iminium salt as the potential Mannich reagent. According to the results of AM1 dynamic calculations, the activation energies of key steps in conventional Mannich reactions between ammonia, formaldehyde and acetaldehyde in neutral and acidic media are 438 8 kJ/mol and 393 9 kJ/mol respectively. The activation energy of the rate controlling step of the Mannich reaction which contains the potential Mannich reagent is 274 7 kJ/mol. Therefore, it can be derived that the potential Mannich reagent can increase the rate of the reaction remarkably. The reasons for this have been discussed in terms of the orbital match and electrostatic interaction between the atoms of reactant complexes. In this paper another different conjectured mechanism of the potential Mannich reagent which can reduce the activation energy is considerably studied.
基金This work was supported by Foundation from President of the Chinese Academic of Science and NSFC.
文摘A novel palladium-catalyzed coupling reaction for the preparation of derivatives of stilbazoles was presented. A series of stilbazoles were synthesized firstly by this highly efficient method. From this reaction it was found that reaction solvent is one of important factors in this catalytic system.
文摘The antitumor activity of 5 fluorouracil 1 acetic acid(HFAA) and its lanthanide complexes(La(FAA) 3, Eu(FAA) 3) were studied. The results show that HFAA, La(FAA) 3 and Eu(FAA) 3 with the concentrations of 1 0×10 -5 ～1 0×10 -2 μg·ml -1 inhibit the colony formation of leukemia cells(L 1210 ) and the growth of transplanted tumor sarcoma 180(S 180 ), hepatic carcinoma(HEPA) and ehrlich ascites tumor(EC) as well. The maximum inhibitory rate of Eu(FAA) 3 for S 180 is 38 4%, that HFAA and La(FAA) 3 for EC are 22 4% and 43 4%, respectively. The life prolongation rate of Eu(FAA) 3 for HEPA bearing mice is as long as 284%.
文摘Dense phase voidage can be estimated by cutting gas flow and following the rate of bed collapse. Abrupt cessation of flow is not possible when excess gas in the windbox can only discharge through the bed. The magnitude of this problem is examined experimentally.
基金This paper was supported by NNSFThis paper was supported by SINOPEK
文摘This paper presents an experimental study on the radial and axial profiles of local particle velocity of flu-idized catalyst(FCC)particles in a circulating fluidized bed of 8000mm in height and 186mm in inside diameterwith a Fiber-Optic Probe Laser Doppler Velocimetry.It has been found that the radial profiles of local particlevelocity are parabolic,even in the centre region and steep in the region near the bed wall,and that the length ofparticle acceleration along the bed height is longer than expected.The following formula has been recommended to correlate the 1 ocal particle velocity with dilute gas-solidflow in the bed:where a,b,c and e are functions of radial positions.
文摘On the basis of vapor pressures, volumes of saturated vapor and liquid, both parameters "a" and "b" in Soave equation of state are treated as temperature dependent and an extended Soave equation is proposed in this work. The VLE for 38 pure components including polar substances have been calculated. The comparison of calculated results with experimental data shows the prediction of liquid density is improved over Soave equation without losing the accuracy of prediction in vapor pressure and vapor density.
文摘The crystal structure of Di-nitratobis(ethylcaprolactam)uranyl(Ⅱ) UO_2[CH_2(CH_2)_4CONC_2H_5]_2(NO_3)_2 was established by a single-crystal X-ray diffraction study.It is triclinie, space group P1, with a=7.171(2), b=8.655(3), c=10.182(5)A, α=78.27(3), β=70.63(3), γ=81.76(3)°, V=581.7(4)A^3, Z=l, Dc=1.94 g.cm^(-3).Final R value is 0.0218.The result reveals that uranyl ion is coordinated to six oxygen atoms, two of them are from two carbonyl groups of ethylcaprolactam and the other four are from two nitrate groups.
文摘Mathematical model is developed to estimate hemoglobin release under hypotonic conditions at microscopic level. The phenomenon of hemoglobin (Hb) release depends on: 1) the dynamics of repeated opening of hemolytic holes and 2) the radial fluctuations of lipid membrane. Both processes are sensitive to the rate of ionic strength decrease within the surrounding medium. Influence of the rate of ionic strength decrease on hemoglobin release is quantified by the model parameters: 1) the specific decrease of erythrocyte radius and 2) the specific decrease of hole radius during single opening time period of hemolytic hole. The prediction of released amount of Hb influenced by the conductive mechanism is equal to 2.9 %. The prediction of total released amount of Hb influenced by the conductive and convective mechanisms is approximately equal to 4 % of the initial amount of Hb within erythrocyte.
文摘The title complex was obtained by repeatly extracting the 0.1 mol/L HCI solution of PdCl2 with the petroleum ether in which p-CH3C6H4SC4H9 was previously dissolved at room temperature. The resulting precipitate, after washed With deionized water and petroleum ether respectively,
文摘A series of hydrogels with lower critical solution temperature (LCST) were prepared and used for the immobilization of chymotrypsin. The activities of the immobilized enzyme decrease when the temperatures are raised above their LCST and recover below their LCST. This property is reversible.
文摘The surface pressure—area isotherms(π—A curves) of 2—heptadecyl imidazole (HIM) Langmuir films at the subphases of deionized water and solutions containing metal ions such as Cu^(2+), Cd^(2+), Ca^(2+), Co^(2+), Ag^+ etc. have been studied. It was formed Langmuir film at the subphase containing Cu^(2+) or Ag^+ ions and its LB film was successfully deposited. The molecular and ionic total energies (E) and stabil. ity energies (△E) forming complexes were computed by CNDO/2 method. The computational results agreed with the experiments.
文摘Kinetics of the steam reformig of n-butane,n-hexane,n-heptane,n-nonane and i-octane on Z409 catalystwere studied at atmospheric pressure by using an internal recycle gradientless reactor.The reaction temperaturewas varied in the range of 743-853K,the steam carbon molar ratio 3-5.The experimental results showed thatthe reforming products contained no hydrocarbon other than methane.In addition,the product distributionof different n-paraffins were similar,but the product distribution of i-octane was different from that of n-paraffins.A reaction scheme for the steam reforming of paraffin has been proposed and the hyperbolic type rateequations were derived.It is clear that the obtained kinetic model could simulate the experimental results ofi-octane as well as different n-paraffins satisfactorily.
文摘The behaviour of water soluble and monomer soluble inhibitors in the emulsion polymerization for CaseI system(e.g.vinyl acetate and vinyl chloride)has been studied.The behaviour of monomer soluble inhibitorsis shown to be quite different from that observed in Case Ⅱ emulsion polymerization system.Model predictionsof the effect of these inhibitors on polymer particle nucleation and growth rate are shown to be in satisfactoryagreement with experimental results.
