For overcoming disadvantages of wood, an esterification process was employed and tetrabromophthalic anhydride (TBPA) was used as a reactive chemical agent to prepare an esterified wood with the high dimensional stabil...For overcoming disadvantages of wood, an esterification process was employed and tetrabromophthalic anhydride (TBPA) was used as a reactive chemical agent to prepare an esterified wood with the high dimensional stability, flame resistance, and resistance to biodegradation from water-leaching. The experimental results indicated that esterification of wood plus maleic anhydride / tetrabromophthalic anhydride / glycerol could endow wood with dimensional stability, the antiswelling efficiency during water absorption (ASEw), reduction in water absorptivity (RWA), antiswelling efficiency during moisture absorption (ASEm), moisture excluding efficiency (MEE), and oxygen index (OI) of treated wood increased with an increase in the weight percent gain (WPG). And the treated wood showed great decay resistance and resistance to water leaching, too.展开更多
The effect of press direction on the thermal expansion, slag resistance, etc. of periclase spinel carbon brick has been studied in this article. The results show that the thermal expansion rate in the direction para...The effect of press direction on the thermal expansion, slag resistance, etc. of periclase spinel carbon brick has been studied in this article. The results show that the thermal expansion rate in the direction parallel to the press axis is larger than that in the direction perpendicular to the press axis and the slag resistance in the direction parallel to the press axis is much better than that in the perpendicular direction. The directional distribution of graphite in the specimen is observed with the microscope.展开更多
Matrix-bound phosphine (PH3), a new form of phosphorus, was found in sediment of Jiaozhou Bay in De-cember 2001. Concentration and distribution of PH3 in dif-ferent layers of sediment with different stations were ana-...Matrix-bound phosphine (PH3), a new form of phosphorus, was found in sediment of Jiaozhou Bay in De-cember 2001. Concentration and distribution of PH3 in dif-ferent layers of sediment with different stations were ana-lyzed. The results show that PH3 concentrations are various with different layers and different stations. PH3 concentra-tions in the bottom layer of sediment (20—30 cm) are usually higher than those in the surface layer (0—4 cm). The highest PH3 concentration in our investigation reaches 685 ng/kg (dry), which is much higher than those in terrestrial paddy soil, marsh and landfill that have been reported up to now. The correlation analysis indicates that there is no apparent correlation between the concentrations of PH3 and inorganic phosphorus in sediment. However, the correlation between the concentrations of phosphine and organic phosphorus in the bottom layer of sediment is remarkable (R2=0.83). It is considered that PH3 in sediment of Jiaozhou Bay is mainly produced from the decomposition of organic phosphorus in the anaerobic condition, and so PH3 concentrations are re-lated to organic phosphorus concentration and anaerobic environment in sediment. The discovery of PH3 in sediment will give people some new ideas on the mechanisms of phos-phorus supplement and biogeochemical cycle in Jiaozhou Bay.展开更多
文摘For overcoming disadvantages of wood, an esterification process was employed and tetrabromophthalic anhydride (TBPA) was used as a reactive chemical agent to prepare an esterified wood with the high dimensional stability, flame resistance, and resistance to biodegradation from water-leaching. The experimental results indicated that esterification of wood plus maleic anhydride / tetrabromophthalic anhydride / glycerol could endow wood with dimensional stability, the antiswelling efficiency during water absorption (ASEw), reduction in water absorptivity (RWA), antiswelling efficiency during moisture absorption (ASEm), moisture excluding efficiency (MEE), and oxygen index (OI) of treated wood increased with an increase in the weight percent gain (WPG). And the treated wood showed great decay resistance and resistance to water leaching, too.
文摘The effect of press direction on the thermal expansion, slag resistance, etc. of periclase spinel carbon brick has been studied in this article. The results show that the thermal expansion rate in the direction parallel to the press axis is larger than that in the direction perpendicular to the press axis and the slag resistance in the direction parallel to the press axis is much better than that in the perpendicular direction. The directional distribution of graphite in the specimen is observed with the microscope.
基金This work was supported by the National Natural Science Foundation of China (Grant Nos. 40025614 and 20177024) and the National 973 Key Basic Re-search Project (Grant No. 2001CB409710).
文摘Matrix-bound phosphine (PH3), a new form of phosphorus, was found in sediment of Jiaozhou Bay in De-cember 2001. Concentration and distribution of PH3 in dif-ferent layers of sediment with different stations were ana-lyzed. The results show that PH3 concentrations are various with different layers and different stations. PH3 concentra-tions in the bottom layer of sediment (20—30 cm) are usually higher than those in the surface layer (0—4 cm). The highest PH3 concentration in our investigation reaches 685 ng/kg (dry), which is much higher than those in terrestrial paddy soil, marsh and landfill that have been reported up to now. The correlation analysis indicates that there is no apparent correlation between the concentrations of PH3 and inorganic phosphorus in sediment. However, the correlation between the concentrations of phosphine and organic phosphorus in the bottom layer of sediment is remarkable (R2=0.83). It is considered that PH3 in sediment of Jiaozhou Bay is mainly produced from the decomposition of organic phosphorus in the anaerobic condition, and so PH3 concentrations are re-lated to organic phosphorus concentration and anaerobic environment in sediment. The discovery of PH3 in sediment will give people some new ideas on the mechanisms of phos-phorus supplement and biogeochemical cycle in Jiaozhou Bay.
