Alteration of technological and optical states of glass activated with chloride ions, entered to the surface of quartz sand and quartz grain by way of sodium chloride was investigated in the article. Concentration opt...Alteration of technological and optical states of glass activated with chloride ions, entered to the surface of quartz sand and quartz grain by way of sodium chloride was investigated in the article. Concentration optimum of activating agent was determined.展开更多
Flue gas pollution is a serious environmental problem that needs to be solved for the sustainable development of China.The surface chemical properties of carbon have great influence on its desulphurization performance...Flue gas pollution is a serious environmental problem that needs to be solved for the sustainable development of China.The surface chemical properties of carbon have great influence on its desulphurization performance.A series of activated carbons (ACs) were prepared using HNO3,H2O2,NH3·H2O and steam as activation agents with the aim to introduce functional groups to carbon surface in the ACs preparation process.The ACs were physically and chemically characterized by iodine and SO2 adsorption,ultimate analysis,Boehm titration,and temperature-programmed reduction (TPR).Results showed that the iodine number and desulphurization capacity of NH3·H2O activated carbon (AC-NH3) increase with both activation time,and its desulphurization capacity also increases with the concentration of activation agent.However,HNO3 activated carbon (AC-HNO3) and H2O2 activated carbon (AC-H2O2) exhibit more complex behavior.Only their iodine numbers increase monotonously with activation time.Compared with steam activated AC (AC-H2O),the nitrogen content increases 0.232% in AC-NH3 and 0.077% in AC-HNO3.The amount of total basic site on AC-HNO3 is 0.19 mmol·g-1 higher than that on AC-H2O.H2O2 activation introduces an additional 0.08 mmol·g-1 carboxyl groups to AC surface than that introduced by steam activation.The desulphurization capacity of ACs in simulate flue gas desulphurization decreases as follows: AC-NH3 】 AC-HNO3 】 AC-H2O2 】 AC-H2O.This sequence is in accord with the SO2 catalytic oxidation/oxidation ratio in the absence of oxygen and the oxidation property reflected by TPR.In the presence of oxygen,all adsorbed SO2 on ACs can be oxidized into SO3.The desulphurization capacity increases differently according to the activation agents;the desulphurization capacity of AC-NH3 and AC-HNO3 improves by 4.8 times,yet AC-H2O increases only by 2.62 as compared with the desulphurization of corresponding ACs in absence of oxygen.展开更多
Film dosage forms (FDs) containing miconazole (MCZ) for the treatment of oral candidiasis were prepared using water-soluble polysaccharides, and the dissolution profiles of MCZ from the FDs were investigated. In addit...Film dosage forms (FDs) containing miconazole (MCZ) for the treatment of oral candidiasis were prepared using water-soluble polysaccharides, and the dissolution profiles of MCZ from the FDs were investigated. In addition, the forms were modified by the addition of a surface active agent to accelerate the drug dissolution rate. Circular films incorporating MCZ were obtained using each polysaccharide. Most FDs were easy to handle and resistant to tearing. No diffraction peaks were observed in the X-ray diffractograms of FDs. FDs prepared with sodium alginate or pullulan immediately swelled and disintegrated in aqueous medium, whereas MCZ incorporated in the FD gradually dissolved. A marked acceleration in the MCZ dissolution rate was observed when FD was prepared with polysaccharide containing a surfactant. These results confirmed that modified FDs are useful for treating localized conditions in the oral cavity, such as oral candidiasis, and that FDs can simplify the administration of drugs to patients.展开更多
Nanometer cerium-zirconium oxide solution Ce1-x ZrxO2 was synthesized by mechanically activated solid state re- action at middle-low temperatures, with Ce2（CO3）3, ZrOCl2-SH2O and H2C2O4·2H2O as raw materials. T...Nanometer cerium-zirconium oxide solution Ce1-x ZrxO2 was synthesized by mechanically activated solid state re- action at middle-low temperatures, with Ce2（CO3）3, ZrOCl2-SH2O and H2C2O4·2H2O as raw materials. The crystal structure and microstructure of the nanometer Ce1-x Zrx O2 were studied with X-ray diffractometry （XRD） and transmission electron microscope （TEM）. The results show that the product is single-cubic-phase solid solution with an average crystal size 19.64 nm. In this article, the influence of surface active agent is also evaluated. Mechanically activated solid state reaction for the preparation of Ce1-xZrxO2 is a new technique of green chemistry without solvent and waste.展开更多
文摘Alteration of technological and optical states of glass activated with chloride ions, entered to the surface of quartz sand and quartz grain by way of sodium chloride was investigated in the article. Concentration optimum of activating agent was determined.
基金supported by the National Natural Science Foundation of China (Grant No. 50204011)the Chemical and Environmental Engineering Lab for the TP-5000(II) adsorption instrument
文摘Flue gas pollution is a serious environmental problem that needs to be solved for the sustainable development of China.The surface chemical properties of carbon have great influence on its desulphurization performance.A series of activated carbons (ACs) were prepared using HNO3,H2O2,NH3·H2O and steam as activation agents with the aim to introduce functional groups to carbon surface in the ACs preparation process.The ACs were physically and chemically characterized by iodine and SO2 adsorption,ultimate analysis,Boehm titration,and temperature-programmed reduction (TPR).Results showed that the iodine number and desulphurization capacity of NH3·H2O activated carbon (AC-NH3) increase with both activation time,and its desulphurization capacity also increases with the concentration of activation agent.However,HNO3 activated carbon (AC-HNO3) and H2O2 activated carbon (AC-H2O2) exhibit more complex behavior.Only their iodine numbers increase monotonously with activation time.Compared with steam activated AC (AC-H2O),the nitrogen content increases 0.232% in AC-NH3 and 0.077% in AC-HNO3.The amount of total basic site on AC-HNO3 is 0.19 mmol·g-1 higher than that on AC-H2O.H2O2 activation introduces an additional 0.08 mmol·g-1 carboxyl groups to AC surface than that introduced by steam activation.The desulphurization capacity of ACs in simulate flue gas desulphurization decreases as follows: AC-NH3 】 AC-HNO3 】 AC-H2O2 】 AC-H2O.This sequence is in accord with the SO2 catalytic oxidation/oxidation ratio in the absence of oxygen and the oxidation property reflected by TPR.In the presence of oxygen,all adsorbed SO2 on ACs can be oxidized into SO3.The desulphurization capacity increases differently according to the activation agents;the desulphurization capacity of AC-NH3 and AC-HNO3 improves by 4.8 times,yet AC-H2O increases only by 2.62 as compared with the desulphurization of corresponding ACs in absence of oxygen.
文摘Film dosage forms (FDs) containing miconazole (MCZ) for the treatment of oral candidiasis were prepared using water-soluble polysaccharides, and the dissolution profiles of MCZ from the FDs were investigated. In addition, the forms were modified by the addition of a surface active agent to accelerate the drug dissolution rate. Circular films incorporating MCZ were obtained using each polysaccharide. Most FDs were easy to handle and resistant to tearing. No diffraction peaks were observed in the X-ray diffractograms of FDs. FDs prepared with sodium alginate or pullulan immediately swelled and disintegrated in aqueous medium, whereas MCZ incorporated in the FD gradually dissolved. A marked acceleration in the MCZ dissolution rate was observed when FD was prepared with polysaccharide containing a surfactant. These results confirmed that modified FDs are useful for treating localized conditions in the oral cavity, such as oral candidiasis, and that FDs can simplify the administration of drugs to patients.
基金Project supported by the Key Project for Industry of Guangdong Province (Grant No,2004A10701005)the Natural Science Foundation of Guangdong Province (Grant No.04205301)
文摘Nanometer cerium-zirconium oxide solution Ce1-x ZrxO2 was synthesized by mechanically activated solid state re- action at middle-low temperatures, with Ce2（CO3）3, ZrOCl2-SH2O and H2C2O4·2H2O as raw materials. The crystal structure and microstructure of the nanometer Ce1-x Zrx O2 were studied with X-ray diffractometry （XRD） and transmission electron microscope （TEM）. The results show that the product is single-cubic-phase solid solution with an average crystal size 19.64 nm. In this article, the influence of surface active agent is also evaluated. Mechanically activated solid state reaction for the preparation of Ce1-xZrxO2 is a new technique of green chemistry without solvent and waste.
