Mg3Al layered double hydroxides (Mg3Al-LDHEPCL) was grafted through free radical polymerization using S2O2-8/S2O2-5 redox initiator.Monomers used for the graft copolymerization were composed of anionic monomers acryli...Mg3Al layered double hydroxides (Mg3Al-LDHEPCL) was grafted through free radical polymerization using S2O2-8/S2O2-5 redox initiator.Monomers used for the graft copolymerization were composed of anionic monomers acrylic acid (AA) and sodium acrylate (SA) as well as cationic monomers trimethylallyl ammonium chloride (TMAAC) and dimethyldiallyl ammonium chloride (DMDAAC).The produced hybrid graft copolymer,Mg3Al-LDHEPCL-g-PAA-PSA-co-PTMAAC-co-PDMDAAC,can be used as polyampholyte sewage treatment agent.The graft copolymerization process was monitored by differential scanning calorimetry (DSC) to obtain the kinetic characteristics in the foamed dispersion polymerization system.The graft copolymerization composition was optimized aiming to achieve lower water content in the sludge and lower COD value in the filtrate.The optimized composition was found to be m(Mg3Al-LDHEPCL )∶m(AA+SA+TMAAC+DMDAAC)=0.12∶1;m(TMAAC+DMDAAC)∶m(AA+SA+TMAAC+DMDAAC)=0.288∶0.712,and the neutralization ratio of AA was 18%—24%.Hydrolysis analog studies in 1.0 mol·L-1 NaOH solution revealed that the layered cluster of Mg3Al-LDHEPCL hydrolyzed into multiple lamellar segments forming a secondary quaternary ammonium polyampholyte that functioned as coagulation agent.These inherent structural characteristics are important factors for improving the dehydration effect significantly.The crystal structures were characterized by XRD and IR.展开更多
Sex expression in Sagittaria guyanensis H.B.K. subsp. lappula (D. Don) Bojin is typically andromonoecious while the other species in the same genus are basically monoecious. The evolutionary advantages of male...Sex expression in Sagittaria guyanensis H.B.K. subsp. lappula (D. Don) Bojin is typically andromonoecious while the other species in the same genus are basically monoecious. The evolutionary advantages of male flowers and hermaphrodite flowers in S. guyanensis subsp. lappula were assessed by measuring sex allocation and pollen movements in two wild populations of the species. Two cultivated populations served as controls. The percentage of male flowers was very low in the two wild populations in Dongxiang, Jiangxi Province and Wuyishan, Fujian Province, viz., 2.48% and 0.96% respectively. In the two cultivated populations, male flower percentage significantly increased when the soil was of higher nutrient content. This indicates that the allocation to male versus female reproduction might change in response to environmental factors. Pollen production per male flower was 4.1 times higher than that of a hermaphrodite flower. The floral shape and size of male and hermaphrodite flowers were similar. No difference was observed between these dimorphological flowers in pollen germination rate in vitro and in the speed of pollen tube growth in vivo . Anthesis was only 4-5 h. Male flowers usually opened 0.5 h earlier than hermaphrodite flowers. An unexpected finding was that no pollen from the male flowers was found on the stigmas of the hermaphrodite flowers, in spite of the occasional visits by insects to both types of flowers in both wild and control populations. A consistent pattern of fruit development was found to exist in open pollinated flowers as well as in flowers that had been bagged. The sex ratios did not have significant influence on fruit set. Approximately 25% of the pistils in a gynoecium failed to develop into fruits because no pollen was deposited on them, indicating that the fruit set of this andromonoecious plant is mainly affected by pollen limitation rather than resource limitation. Reproduction in S. guyanensis subsp. lappula in the habitats was dependent on self_pollination in hermaphrodite flowers. The male flowers in this species might be a potential source of additional pollination and may facilitate cross_pollination. The fact that the flowers of monoecious species in Sagittaria pollinated by a wide diversity of insect visitors may contribute enormously to the diversification of sex expression in this genus.展开更多
Two-phase anaerobic digestion process is influenced by acid control for hydrogen production, reaction temperature, substrate detention time, sludge activity, and granular formation. Al of these technological parameter...Two-phase anaerobic digestion process is influenced by acid control for hydrogen production, reaction temperature, substrate detention time, sludge activity, and granular formation. Al of these technological parameters are directly related to success or failure of the system operation and treatment effect.展开更多
By combining Argos drifter buoys and TOPEX/POSEIDON altimeter data, the time series of sea-surface velocity fields in the Kuroshio Current (KC) and adjacent regions are established. And the variability of the KC from ...By combining Argos drifter buoys and TOPEX/POSEIDON altimeter data, the time series of sea-surface velocity fields in the Kuroshio Current (KC) and adjacent regions are established. And the variability of the KC from the Luzon Strait to the Tokara Strait is studied based on the velocity fields. The results show that the dominant variability period varies in different segments of the KC: The primary period near the Luzon Strait and to the east of Taiwan Island is the intra-seasonal time scale; the KC on the continental shelf of the ECS is the steadiest segment without obvious periodicity, while the Tokara Strait shows the period of seasonal variability. The diverse periods are caused by the Rossby waves propagating from the interior ocean, with adjustments in topography of island chain and local wind stress.展开更多
文摘Mg3Al layered double hydroxides (Mg3Al-LDHEPCL) was grafted through free radical polymerization using S2O2-8/S2O2-5 redox initiator.Monomers used for the graft copolymerization were composed of anionic monomers acrylic acid (AA) and sodium acrylate (SA) as well as cationic monomers trimethylallyl ammonium chloride (TMAAC) and dimethyldiallyl ammonium chloride (DMDAAC).The produced hybrid graft copolymer,Mg3Al-LDHEPCL-g-PAA-PSA-co-PTMAAC-co-PDMDAAC,can be used as polyampholyte sewage treatment agent.The graft copolymerization process was monitored by differential scanning calorimetry (DSC) to obtain the kinetic characteristics in the foamed dispersion polymerization system.The graft copolymerization composition was optimized aiming to achieve lower water content in the sludge and lower COD value in the filtrate.The optimized composition was found to be m(Mg3Al-LDHEPCL )∶m(AA+SA+TMAAC+DMDAAC)=0.12∶1;m(TMAAC+DMDAAC)∶m(AA+SA+TMAAC+DMDAAC)=0.288∶0.712,and the neutralization ratio of AA was 18%—24%.Hydrolysis analog studies in 1.0 mol·L-1 NaOH solution revealed that the layered cluster of Mg3Al-LDHEPCL hydrolyzed into multiple lamellar segments forming a secondary quaternary ammonium polyampholyte that functioned as coagulation agent.These inherent structural characteristics are important factors for improving the dehydration effect significantly.The crystal structures were characterized by XRD and IR.
文摘Sex expression in Sagittaria guyanensis H.B.K. subsp. lappula (D. Don) Bojin is typically andromonoecious while the other species in the same genus are basically monoecious. The evolutionary advantages of male flowers and hermaphrodite flowers in S. guyanensis subsp. lappula were assessed by measuring sex allocation and pollen movements in two wild populations of the species. Two cultivated populations served as controls. The percentage of male flowers was very low in the two wild populations in Dongxiang, Jiangxi Province and Wuyishan, Fujian Province, viz., 2.48% and 0.96% respectively. In the two cultivated populations, male flower percentage significantly increased when the soil was of higher nutrient content. This indicates that the allocation to male versus female reproduction might change in response to environmental factors. Pollen production per male flower was 4.1 times higher than that of a hermaphrodite flower. The floral shape and size of male and hermaphrodite flowers were similar. No difference was observed between these dimorphological flowers in pollen germination rate in vitro and in the speed of pollen tube growth in vivo . Anthesis was only 4-5 h. Male flowers usually opened 0.5 h earlier than hermaphrodite flowers. An unexpected finding was that no pollen from the male flowers was found on the stigmas of the hermaphrodite flowers, in spite of the occasional visits by insects to both types of flowers in both wild and control populations. A consistent pattern of fruit development was found to exist in open pollinated flowers as well as in flowers that had been bagged. The sex ratios did not have significant influence on fruit set. Approximately 25% of the pistils in a gynoecium failed to develop into fruits because no pollen was deposited on them, indicating that the fruit set of this andromonoecious plant is mainly affected by pollen limitation rather than resource limitation. Reproduction in S. guyanensis subsp. lappula in the habitats was dependent on self_pollination in hermaphrodite flowers. The male flowers in this species might be a potential source of additional pollination and may facilitate cross_pollination. The fact that the flowers of monoecious species in Sagittaria pollinated by a wide diversity of insect visitors may contribute enormously to the diversification of sex expression in this genus.
基金Supported by Yunnan S&T Innovation Platform Construction Project(2013DH041)National Natural Science Foundation of China(51366015)Specialized Research Fund for the Doctoral Program of Higher Education of China(20135303110001)~~
文摘Two-phase anaerobic digestion process is influenced by acid control for hydrogen production, reaction temperature, substrate detention time, sludge activity, and granular formation. Al of these technological parameters are directly related to success or failure of the system operation and treatment effect.
基金Supported by the National Basic Research Program of China (973 Program, Nos. 2007CB411804, 2005CB422303)the NSFC (No. 40706006)+2 种基金the Key Project of International Science and Technology Cooperation Program of China (No. 2006DFB21250)the "111 Project" (B07036)the Program for New Century Excellent Talents in University (NECT-07-0781)
文摘By combining Argos drifter buoys and TOPEX/POSEIDON altimeter data, the time series of sea-surface velocity fields in the Kuroshio Current (KC) and adjacent regions are established. And the variability of the KC from the Luzon Strait to the Tokara Strait is studied based on the velocity fields. The results show that the dominant variability period varies in different segments of the KC: The primary period near the Luzon Strait and to the east of Taiwan Island is the intra-seasonal time scale; the KC on the continental shelf of the ECS is the steadiest segment without obvious periodicity, while the Tokara Strait shows the period of seasonal variability. The diverse periods are caused by the Rossby waves propagating from the interior ocean, with adjustments in topography of island chain and local wind stress.
