We studied the effects of nitrogen （N） and phosphorus （P） supply on Fv/Fm （maximal quantum yield of photosystem Ⅱ） in the algae Chaetoceros debilis, Dicrateria inornata, Platymonas subcordiformis and Heterosigm...We studied the effects of nitrogen （N） and phosphorus （P） supply on Fv/Fm （maximal quantum yield of photosystem Ⅱ） in the algae Chaetoceros debilis, Dicrateria inornata, Platymonas subcordiformis and Heterosigma akashiwo to determine the sensitivity of Fv/Fm to P-limitation of the four species. Obvious decrease of Fv/Fm value was monitored in periods of P-depletion, the decrease showing different magnitudes among algal species. A more clear decrease of Fv/Fm in Platymonas subcordiformis and Heterosigma akashiwo was observed, compared with that in Chaetoceros debilis and Dicrateria inornata. After the re-supply of P, the index Fv/Fm of the four species all recovered quickly in 24h. Cell division was maintained and chlorophyll content continued to increase until the end of the experiment in Platymonas subcordiformis and Heterosigma akashiwo, while in Chaetoceros debilis and Dicrateria inornata, the division stopped in the later period when the growth of organisms came into the stationary phase. The most obvious respond of chlorophyll content to P-additions was observed in Heterosigma akashiwo culture in 24 h. The sensitivity of Fv/Fm to nutrient limitations is different among algal species, and much should be done to improve the application of this index.展开更多
Lower temperature or polyphosphate limitation is the favorable condition to enrich polyphosphate-accumulating organisms (PAOs) or glycogen accumulating organisms (GAOs) in biological phosphorus removal process. In thi...Lower temperature or polyphosphate limitation is the favorable condition to enrich polyphosphate-accumulating organisms (PAOs) or glycogen accumulating organisms (GAOs) in biological phosphorus removal process. In this study,a sludge highly enriched in PAOs was used to investigate the metabolic pathways and carbon transformation in batch tests under the two conditions for elucidating the contradiction. The results showed that the PAOs are able to take up acetate and store it as polyhydroxyalkanoates (PHA) in anaerobic phase although the poly-P pool is emptied through washing with negligible P release. The stoichiometric ratios of the PHB and PHV production and glycogen degradation to the acetate uptake combined with the Nile blue staining indicated that the PAOs possess the anaerobic metabolism of GAOs using glycogen as the sole energy source,but no transformation of PAOs to GAOs is observed. After reconverting to the normal operation,phosphorus uptake and release are recovered the same as the parent reactor.展开更多
We discussed a class of p-Laplacian boundary problems on a bounded smooth domain, the nonlinearity is odd symmetric and limit subcritical growing at infinite. A sequence of critical values of the variational functiona...We discussed a class of p-Laplacian boundary problems on a bounded smooth domain, the nonlinearity is odd symmetric and limit subcritical growing at infinite. A sequence of critical values of the variational functional was constructed after the general- ized Palais-Smale condition was verified. We obtain that the problem possesses infinitely many solutions and corresponding energy levels of the functional pass to positive infinite. The result is a generalization of a similar problem in the case of subcritical.展开更多
The original data of Nilsson-Ehle experiment in wheat were analyzed with existent genetic knowledge. It indicated that the core of polygenic hypothesis from this experiment was that a character similarity produced by ...The original data of Nilsson-Ehle experiment in wheat were analyzed with existent genetic knowledge. It indicated that the core of polygenic hypothesis from this experiment was that a character similarity produced by additive effect of multiple genes was the basis of continuous variation. Its precondition was for effective genes to have equal effect, to show merodominance and binomial distribution and to inherit independently. In fact, quantitative characters were determined by many genes with different property, effect and behavior. So it was difficult to solve all problems of continuous variation by the aid of polygenic hypothesis. The researchers should seek new ways. With Mendelian group as research object and by means of Lyapunov central limit theorem it was proved that both genotypic value G and the environmental effect in a niche E were subordinated to the normal distribution and respectively. According to additivity of the normal distribution the phenotype P = G + E also obeyed the normal distribution P = G + E ~ and quantitative characters showed continuous variation, whether or not the linkage was presented, whether or not every gene effect was equal, whether or not there were dominance and what kind of dominance between alleles. Moreover it was discussed that the quantitative characters in self-fertilized organism and clone were submitted to the normal distribution and presented continuous variation too.展开更多
基金support from the National Natural Science Foundation of China (No. 41076065)the National Basic Research Program of China (973 Program) (No. 2010CB428701)
文摘We studied the effects of nitrogen （N） and phosphorus （P） supply on Fv/Fm （maximal quantum yield of photosystem Ⅱ） in the algae Chaetoceros debilis, Dicrateria inornata, Platymonas subcordiformis and Heterosigma akashiwo to determine the sensitivity of Fv/Fm to P-limitation of the four species. Obvious decrease of Fv/Fm value was monitored in periods of P-depletion, the decrease showing different magnitudes among algal species. A more clear decrease of Fv/Fm in Platymonas subcordiformis and Heterosigma akashiwo was observed, compared with that in Chaetoceros debilis and Dicrateria inornata. After the re-supply of P, the index Fv/Fm of the four species all recovered quickly in 24h. Cell division was maintained and chlorophyll content continued to increase until the end of the experiment in Platymonas subcordiformis and Heterosigma akashiwo, while in Chaetoceros debilis and Dicrateria inornata, the division stopped in the later period when the growth of organisms came into the stationary phase. The most obvious respond of chlorophyll content to P-additions was observed in Heterosigma akashiwo culture in 24 h. The sensitivity of Fv/Fm to nutrient limitations is different among algal species, and much should be done to improve the application of this index.
基金Sponsored by the Major Science and Technology Program for Water Pollution Control and Treatment (Grant No.2008ZX07207-005-02)
文摘Lower temperature or polyphosphate limitation is the favorable condition to enrich polyphosphate-accumulating organisms (PAOs) or glycogen accumulating organisms (GAOs) in biological phosphorus removal process. In this study,a sludge highly enriched in PAOs was used to investigate the metabolic pathways and carbon transformation in batch tests under the two conditions for elucidating the contradiction. The results showed that the PAOs are able to take up acetate and store it as polyhydroxyalkanoates (PHA) in anaerobic phase although the poly-P pool is emptied through washing with negligible P release. The stoichiometric ratios of the PHB and PHV production and glycogen degradation to the acetate uptake combined with the Nile blue staining indicated that the PAOs possess the anaerobic metabolism of GAOs using glycogen as the sole energy source,but no transformation of PAOs to GAOs is observed. After reconverting to the normal operation,phosphorus uptake and release are recovered the same as the parent reactor.
基金Project supported by the National Natural Science Foundation of China(No.10371045)the Natural Science Foundation of Guangdong Province of China(No.5005930)
文摘We discussed a class of p-Laplacian boundary problems on a bounded smooth domain, the nonlinearity is odd symmetric and limit subcritical growing at infinite. A sequence of critical values of the variational functional was constructed after the general- ized Palais-Smale condition was verified. We obtain that the problem possesses infinitely many solutions and corresponding energy levels of the functional pass to positive infinite. The result is a generalization of a similar problem in the case of subcritical.
文摘The original data of Nilsson-Ehle experiment in wheat were analyzed with existent genetic knowledge. It indicated that the core of polygenic hypothesis from this experiment was that a character similarity produced by additive effect of multiple genes was the basis of continuous variation. Its precondition was for effective genes to have equal effect, to show merodominance and binomial distribution and to inherit independently. In fact, quantitative characters were determined by many genes with different property, effect and behavior. So it was difficult to solve all problems of continuous variation by the aid of polygenic hypothesis. The researchers should seek new ways. With Mendelian group as research object and by means of Lyapunov central limit theorem it was proved that both genotypic value G and the environmental effect in a niche E were subordinated to the normal distribution and respectively. According to additivity of the normal distribution the phenotype P = G + E also obeyed the normal distribution P = G + E ~ and quantitative characters showed continuous variation, whether or not the linkage was presented, whether or not every gene effect was equal, whether or not there were dominance and what kind of dominance between alleles. Moreover it was discussed that the quantitative characters in self-fertilized organism and clone were submitted to the normal distribution and presented continuous variation too.
