The effect of silica nano-particles,tetraethyl orthosilicate (TEOS) and sodium silicate in solution culture on wheat powdery mildew and its action mechanism to pathogen attack were studied. The results showed that whe...The effect of silica nano-particles,tetraethyl orthosilicate (TEOS) and sodium silicate in solution culture on wheat powdery mildew and its action mechanism to pathogen attack were studied. The results showed that wheat seedlings cultured in nutrient solution with silicon compounds alleviated wheat powdery mil-dew,the control efficacies of TEOS and sodium silicate treatments were 54.08% and 51.36%,respectively,but that of silica nano-particles treatment was only 1.02%. Scanning electron micrograph and X-ray energy dispersive analysis (SEM-EDX) showed that wheat leaves cultured in nutrient solution with TEOS and sodium silicate had more silicon deposition than that of silica nano-particles. It indicated that wheat possessed the equal good imbibe ability to TEOS and sodium silicate,but poor to silicate nano-particles. When wheat leaves were infected with Blumeria graminisf.sptritici,silicon might has a physical prohibition effect to pathogen spore penetration.展开更多
The flotation of diaspore and three kinds of silicate minerals, including kaolinite, illite and pyrophyllite, using an organosilicon cationic surfactant (TAS101) as collector and starch as depressant was investigated....The flotation of diaspore and three kinds of silicate minerals, including kaolinite, illite and pyrophyllite, using an organosilicon cationic surfactant (TAS101) as collector and starch as depressant was investigated. The results show that both diaspore and aluminosilicate minerals float readily with organosilicon cationic collector TAS101 at pH values of 4 to 10. Starch has a strong depression effect for diaspore in the alkaline pH region but has little influence on the flotation of aluminosilicate minerals. It is possible to separate diaspore from aluminosilicate minerals using the organosilicon cationic collector and starch depressant. Further studies of bauxite ore flotation were also conducted, and the reverse flotation separation process was adopted. The concentrates with the mass ratio of Al2O3 to SiO2 of 9.58 and Al2O3 recovery of 83.34% are obtained from natural bauxite ore with the mass ratio of Al2O3 to SiO2 of 6.1 at pH value of 11 using the organosilicon cationic collector and starch depressant.展开更多
Aim To study the distribution pattern, antineoplastic activity and immunocompetence of a novel organoselenium compound Eb and investigate its in vivo antineoplastic potential. Methods Eb was administered to Kunming ...Aim To study the distribution pattern, antineoplastic activity and immunocompetence of a novel organoselenium compound Eb and investigate its in vivo antineoplastic potential. Methods Eb was administered to Kunming mice (dosage, 0.1 g·kg^(-1)·d^(-1)) intragastrically for 7 successive days. The contents of selenium in heart, liver, spleen, kidneys, lungs, stomach, brain, muscle, and bone were determined by fluorometric method on the eighth day. MTT assay was used to study tumor growth inhibition of Eb in vitro, and lymphocyte transformation, hemolysin formation and phagocytosis assay were used to study its immunocompetence. Results After 7 days′ administration of Eb, the tissue contents of sele-(nium) in liver, spleen, lungs, kidneys, and bone of mice increased, especially those in liver and spleen increased significan-tly, compared with controls; but no significant changes of such contents were found in muscle, heart, brain, and stomach. Eb demonstrated inhibitory effects on human Bel-7402, BGC-823, and Calu-3 cancer cell lines in vitro. Eb also showed ability to enhance lymphocyte transformation and serum hemolysin formation in vitro and increase the phagocytosis of macrophages. Conclusion The validated antitumor and immunostimulatory activities of Eb suggest a hypothesis that Eb may behave as a biological response modifier when used as an antitumor agent. Eb is worthy of further study in developing a new antineoplastic and immunity enhancing agent in the light of its antitumor activity, immunocompetence and specific distribution in liver, lungs, kidneys, bone, and spleen.展开更多
Shape-selective catalysts for the disproportionation of toluene were prepared by the modification of the cylinder-shaped ZSM-5 zeolite extrudates with chemical liquid deposition with TEOS （tetraethyl orthosilicate）....Shape-selective catalysts for the disproportionation of toluene were prepared by the modification of the cylinder-shaped ZSM-5 zeolite extrudates with chemical liquid deposition with TEOS （tetraethyl orthosilicate）.Various parameters for preparing catalysts were changed to investigate the suitable conditions.The resulting cata-lysts were tested in a pressured fixed bed reactor and characterized by SEM （scanning electron microscopy）.The conversion of toluene and para-xylene selectivity were influenced remarkably by the n（SiO2）/n（Al2O3） ratio of ZSM-5 zeolite,the type and amount of deposition agent,acid and solvent used,and the time and cycle of deposition treatment.TEOS was proved to be a more efficient agent than the conventional polysiloxanes when the deposition amount was low.The catalyst prepared at the suitable conditions exhibited a high para-xylene selectivity of 91.1% with considerable high conversion of 25.6%.SEM analyses confirmed the formation of a layer of amorphous silica on the external surface of ZSM-5 zeolie crystals,which was responsible for the highly enhanced shape-selectivity.展开更多
The liquid-phase hydrogenation of butyronitrile to saturated amines was studied on silica- supported Ni catalysts prepared by either incipient-wetness impregnation (Ni/SiO2-I) or ammonia (Ni/SiO2-A) methods. A Ni/SiO2...The liquid-phase hydrogenation of butyronitrile to saturated amines was studied on silica- supported Ni catalysts prepared by either incipient-wetness impregnation (Ni/SiO2-I) or ammonia (Ni/SiO2-A) methods. A Ni/SiO2-Al2O3-I sample was also used. Ni/SiO2-I was a non-acidic catalyst containing large Ni^0 particles of low interaction with the support, while Ni/SiO2-A was an acidic catalyst due to the presence of Ni^2+ species in Ni phyllosilicates of low reducibility. Ni/SiO2-I formed essentially butylamine (80%), and dibutylamine as the only byproduct. In contrast, Ni/SiO2-A yielded a mixture of dibutylamine (49%) and tributylamine (45%), being the formation of butylamine almost completely suppressed. The selective formation of secondary and tertiary amines on Ni/SiO2-A was explained by considering that butylamine is not release to the liquid phase during the reaction because it is strongly adsorbed on surface acid sites contiguous to Ni^0 atoms, thereby favoring the butylimine/butylamine condensation to higher amines between adsorbed species.展开更多
The effect of particle size of silica, as catalyst binder, on the chemical and mechanical properties of iron based FT catalyst was studied in this work. The samples were characterized using XRD, BET, TEM, FT-IR, and H...The effect of particle size of silica, as catalyst binder, on the chemical and mechanical properties of iron based FT catalyst was studied in this work. The samples were characterized using XRD, BET, TEM, FT-IR, and H2-TPR, re- spectively. The attrition resistance and the FT activity were tested. Si-8-Si-15 catalysts prepared with 8-15 nm silica sol show good attrition resistance （attrition loss 〈 4%）, especially Si-13 with an attrition loss of 1.89%. He- matite appeared in XRD patterns when silica sol above 15 nm is used. TEM micrographs show that no obvious SiO2 particles appear when silica sol particle with size less than 8 nm was used, but SiO2 particles coated with small ferrihydrite particles appear when silica sol above 8 nm was used. Si-O-Si vibration peak in FT-IR spectra increases with increasing silica sol size. Samples prepared with silica sol show good stability of FT reactions, and the average molecular weight of FT products increases with the increase of SiO2 particle.展开更多
文摘The effect of silica nano-particles,tetraethyl orthosilicate (TEOS) and sodium silicate in solution culture on wheat powdery mildew and its action mechanism to pathogen attack were studied. The results showed that wheat seedlings cultured in nutrient solution with silicon compounds alleviated wheat powdery mil-dew,the control efficacies of TEOS and sodium silicate treatments were 54.08% and 51.36%,respectively,but that of silica nano-particles treatment was only 1.02%. Scanning electron micrograph and X-ray energy dispersive analysis (SEM-EDX) showed that wheat leaves cultured in nutrient solution with TEOS and sodium silicate had more silicon deposition than that of silica nano-particles. It indicated that wheat possessed the equal good imbibe ability to TEOS and sodium silicate,but poor to silicate nano-particles. When wheat leaves were infected with Blumeria graminisf.sptritici,silicon might has a physical prohibition effect to pathogen spore penetration.
基金Project(51304085)supported by the National Natural Science Foundation of ChinaProject(GJJ12363)supported by the Education Department of Jiangxi Province,ChinaProject(20142BAB216021)supported by the Natural Science Foundation of Jiangxi Province,China
文摘The flotation of diaspore and three kinds of silicate minerals, including kaolinite, illite and pyrophyllite, using an organosilicon cationic surfactant (TAS101) as collector and starch as depressant was investigated. The results show that both diaspore and aluminosilicate minerals float readily with organosilicon cationic collector TAS101 at pH values of 4 to 10. Starch has a strong depression effect for diaspore in the alkaline pH region but has little influence on the flotation of aluminosilicate minerals. It is possible to separate diaspore from aluminosilicate minerals using the organosilicon cationic collector and starch depressant. Further studies of bauxite ore flotation were also conducted, and the reverse flotation separation process was adopted. The concentrates with the mass ratio of Al2O3 to SiO2 of 9.58 and Al2O3 recovery of 83.34% are obtained from natural bauxite ore with the mass ratio of Al2O3 to SiO2 of 6.1 at pH value of 11 using the organosilicon cationic collector and starch depressant.
文摘Aim To study the distribution pattern, antineoplastic activity and immunocompetence of a novel organoselenium compound Eb and investigate its in vivo antineoplastic potential. Methods Eb was administered to Kunming mice (dosage, 0.1 g·kg^(-1)·d^(-1)) intragastrically for 7 successive days. The contents of selenium in heart, liver, spleen, kidneys, lungs, stomach, brain, muscle, and bone were determined by fluorometric method on the eighth day. MTT assay was used to study tumor growth inhibition of Eb in vitro, and lymphocyte transformation, hemolysin formation and phagocytosis assay were used to study its immunocompetence. Results After 7 days′ administration of Eb, the tissue contents of sele-(nium) in liver, spleen, lungs, kidneys, and bone of mice increased, especially those in liver and spleen increased significan-tly, compared with controls; but no significant changes of such contents were found in muscle, heart, brain, and stomach. Eb demonstrated inhibitory effects on human Bel-7402, BGC-823, and Calu-3 cancer cell lines in vitro. Eb also showed ability to enhance lymphocyte transformation and serum hemolysin formation in vitro and increase the phagocytosis of macrophages. Conclusion The validated antitumor and immunostimulatory activities of Eb suggest a hypothesis that Eb may behave as a biological response modifier when used as an antitumor agent. Eb is worthy of further study in developing a new antineoplastic and immunity enhancing agent in the light of its antitumor activity, immunocompetence and specific distribution in liver, lungs, kidneys, bone, and spleen.
基金Supported by the Key Natural Science Foundation for Universities of Jiangsu Province（06KJA53012） the National Natural Science Foundation of China（20776069 20976084）
文摘Shape-selective catalysts for the disproportionation of toluene were prepared by the modification of the cylinder-shaped ZSM-5 zeolite extrudates with chemical liquid deposition with TEOS （tetraethyl orthosilicate）.Various parameters for preparing catalysts were changed to investigate the suitable conditions.The resulting cata-lysts were tested in a pressured fixed bed reactor and characterized by SEM （scanning electron microscopy）.The conversion of toluene and para-xylene selectivity were influenced remarkably by the n（SiO2）/n（Al2O3） ratio of ZSM-5 zeolite,the type and amount of deposition agent,acid and solvent used,and the time and cycle of deposition treatment.TEOS was proved to be a more efficient agent than the conventional polysiloxanes when the deposition amount was low.The catalyst prepared at the suitable conditions exhibited a high para-xylene selectivity of 91.1% with considerable high conversion of 25.6%.SEM analyses confirmed the formation of a layer of amorphous silica on the external surface of ZSM-5 zeolie crystals,which was responsible for the highly enhanced shape-selectivity.
基金the Universidad Nacional del Litoral (UNL)Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)Agencia Nacional de Promoción Científica y Tecnológica (ANPCyT ), Argentina, for the financial support of this work
文摘The liquid-phase hydrogenation of butyronitrile to saturated amines was studied on silica- supported Ni catalysts prepared by either incipient-wetness impregnation (Ni/SiO2-I) or ammonia (Ni/SiO2-A) methods. A Ni/SiO2-Al2O3-I sample was also used. Ni/SiO2-I was a non-acidic catalyst containing large Ni^0 particles of low interaction with the support, while Ni/SiO2-A was an acidic catalyst due to the presence of Ni^2+ species in Ni phyllosilicates of low reducibility. Ni/SiO2-I formed essentially butylamine (80%), and dibutylamine as the only byproduct. In contrast, Ni/SiO2-A yielded a mixture of dibutylamine (49%) and tributylamine (45%), being the formation of butylamine almost completely suppressed. The selective formation of secondary and tertiary amines on Ni/SiO2-A was explained by considering that butylamine is not release to the liquid phase during the reaction because it is strongly adsorbed on surface acid sites contiguous to Ni^0 atoms, thereby favoring the butylimine/butylamine condensation to higher amines between adsorbed species.
基金financial support from Shenhua Group and Zhejiang University of Technology is highly acknowledged for the catalyst test
文摘The effect of particle size of silica, as catalyst binder, on the chemical and mechanical properties of iron based FT catalyst was studied in this work. The samples were characterized using XRD, BET, TEM, FT-IR, and H2-TPR, re- spectively. The attrition resistance and the FT activity were tested. Si-8-Si-15 catalysts prepared with 8-15 nm silica sol show good attrition resistance （attrition loss 〈 4%）, especially Si-13 with an attrition loss of 1.89%. He- matite appeared in XRD patterns when silica sol above 15 nm is used. TEM micrographs show that no obvious SiO2 particles appear when silica sol particle with size less than 8 nm was used, but SiO2 particles coated with small ferrihydrite particles appear when silica sol above 8 nm was used. Si-O-Si vibration peak in FT-IR spectra increases with increasing silica sol size. Samples prepared with silica sol show good stability of FT reactions, and the average molecular weight of FT products increases with the increase of SiO2 particle.
