[ Objective] The aim of this paper was to investigate the genetic diversity of mitochondrial DNA D-loop sequences of Cheilinus undulatus populations. [Method] Twenty-five individuals of C. undu/atus were collected fro...[ Objective] The aim of this paper was to investigate the genetic diversity of mitochondrial DNA D-loop sequences of Cheilinus undulatus populations. [Method] Twenty-five individuals of C. undu/atus were collected from the offshore area of Hainan Province. PCR and cloning techniques were used to clone and purify the mtDNA D-loop sequences of C. undu/atus populations （n =25）, about 1 400 bp long PCR product was obtained. ClustalX software was adopted for sequence alignment, and results were imported into MEGAS. 0. [ Result] According to experimental results, 66 mutation sites were detected from 25 individuals, including 0 deletion, 4 inserts, 59 transition sites, 2 transversion sites and 1 transition-transversion site. Pairwise genetic distances of these 25 individuals were calcu- lated by using MEGA5.0 software. Based on that, NJ phylogenetic tree of these 25 individuals was constructed. Analysis of C. undulatus populations using DNASP software showed that the polymorphic site number （S） was 62, nucleotide diversity （Pi） was 0.006 06, and average number of nucleotide differences （K） was 6. 907. [ Conclusion] Overall, there was no significant variation among mtDNA D-loops of C. undulatus populations. Key words展开更多
The coupled CFD-DEM method with the JKR(Johnson-Kendall-Roberts)model for describing the contact adhesion of dust to filter particles(FPs)is used to simulate the distribution pattern of dust particle deposition in the...The coupled CFD-DEM method with the JKR(Johnson-Kendall-Roberts)model for describing the contact adhesion of dust to filter particles(FPs)is used to simulate the distribution pattern of dust particle deposition in the granular bed filter(GBF)with multi-layer media.The minimum inlet flow velocity must meet the requirement that the contact probability between dust and FPs is in the high contact probability region.The air flow forms vortices on the leeward side of the FPs and changes abruptly at the intersection of different particle size FPs layers.Dust particles form large deposits at the intersection of the first and second layers and the different particle size filter layers.Dual element multilayer GBF can further optimize the bed structure by interlacing filter layers with different particle sizes.Compared with single particle size multi-layer GBF,the bed pressure drop is reduced by 40.24%-50.65%and the dust removal efficiency is increased by 21.93%-55.09%.展开更多
Filtration tests were conducted on a granular bed filter with layered drawers filled with corundum particles with sizes between either 1 mm and 1.5 mm or 2 mm and 3 mm or with quartz sand particles with sizes between ...Filtration tests were conducted on a granular bed filter with layered drawers filled with corundum particles with sizes between either 1 mm and 1.5 mm or 2 mm and 3 mm or with quartz sand particles with sizes between 0.125 mm and 1.5 mm.Filtration velocity,filter particle thickness,and filter particle size were all found to influence the filtration efficiency and the pressure drop of both the fixed granular bed and the layered-drawer granular bed.Granular strata with different thickness ratios also strongly influenced the filtration efficiency and pressure drop.For a granular bed with two sizes of filter particles,the coarse granules in the upper layer capture dust with large particle sizes,while the fine granules in the lower layer capture dust with smaller particle sizes that passes through the filter cake and upper layer.Optimal operating conditions were determined at which the filtration efficiency was found to be 99.42%with a bed pressure drop of 320 Pa.展开更多
The filtration of mixed dust that included a small number of melted(liquid)particles was studied in an experimental granular bed filter(GBF).Results show that the collection efficiency of dust containing melted partic...The filtration of mixed dust that included a small number of melted(liquid)particles was studied in an experimental granular bed filter(GBF).Results show that the collection efficiency of dust containing melted particles is higher than that of dust composed of solid particles but the pressure drop from the former is higher than that of the latter.The collection efficiency and pressure drop increase as the concentration of melted particles increases.A surface sliding GBF exhibits good comprehensive performance when filtering dust,especially dust containing a mix of solid and liquid particles.The effects of the gas temperature,gas velocity,sliding filter bed thickness,and sliding collector flux on filter performance were also examined.Based on the experimental results,correlations for the collection efficiency and pressure drop for mixed dust are presented.展开更多
Granular bed filters can effectively filter adhesive dust in high-temperature flue gas.In this study.polyvinyl chloride(PVC)powder was used as adhesive dust,and the mixture of PVC and ash powder was used to simulate s...Granular bed filters can effectively filter adhesive dust in high-temperature flue gas.In this study.polyvinyl chloride(PVC)powder was used as adhesive dust,and the mixture of PVC and ash powder was used to simulate solid and adhesive mixed dust.The effects of gas temperature,velocity,and inlet adhesive dust mass content on dust distribution in granular bed(GBF)were discussed.Results show that the mixed dust mainly accumulates on the upper part of the granular bed,and the mass of the collected dust decreases exponentially from the upper layer to the bottom layer in the GBF.The adhesive dust content collected in each layer differs from that of the incoming dust,and their deviation varies approximately linearly along with the depth of the bed.The total dust distribution and adhesive dust content deviation are influenced by gas temperature and inlet adhesive dust content but independent of gas velocity.The correlations of dust distribution of solid and adhesive mixed dust are presented based on the experimental results.展开更多
The effects of the filtering granule particle size and filtration superficial velocity on the dust particle size distribution in different layers of a granular bed system are discussed herein.A multilayer drawer granu...The effects of the filtering granule particle size and filtration superficial velocity on the dust particle size distribution in different layers of a granular bed system are discussed herein.A multilayer drawer granular bed filtration system was designed for these experiments based on filtering fly ash from a power plant.After a 1-h experiment,47.8% of dust particles smaller than 2.5μm,63.7% of dust particles smaller than 10μm,and 39.1% of dust particles larger than 10μm were captured by the granular bed(corresponding to initial volume fractions of 6%,19.3%,and 80.7%,respectively).Large dust particles were more easily trapped by the granular bed than small dust particles.Increasing the size of the filter granules and increasing the superficial velocity of the inlet flue gas were both effective ways to enhance the dust-holding capacity of the granular media throughout the granular bed.展开更多
In order to limit global warming to 2°C,countries have adopted carbon capture and storage(CCS)technologies to reduce greenhouse gas emission.However,it is currently facing challenges such as controversial investm...In order to limit global warming to 2°C,countries have adopted carbon capture and storage(CCS)technologies to reduce greenhouse gas emission.However,it is currently facing challenges such as controversial investment costs,unclear policies,and reduction of new energy power generation costs.In particular,some CCS projects are at a standstill.To promote the development of CCS projects in different countries,this paper reviews and compares energy conservation and emission reduction policies and different national goals.From a policy perspective,CCS-driven policies are analyzed.Based on this,corresponding policy recommendations are put forward,in order to promote the healthy development of global CCS technology and deal with climate issues more effectively.With less than 10 years away from the short-term goal,promoting the development and application of CCS projects requires scientific research from universities,enterprises and governments in order to attain zero or negative CO_(2)emission.On the basis of focusing on the development of CCS technology,according to the actual situation of each country,the appropriate application of CCS engineering should focus on the development of science and technology,rather than a unified requirement around the world.展开更多
基金Supported by National Natural Science Foundation of China(40966003)Natural Science Foundation of Hainan Province(809009)
文摘[ Objective] The aim of this paper was to investigate the genetic diversity of mitochondrial DNA D-loop sequences of Cheilinus undulatus populations. [Method] Twenty-five individuals of C. undu/atus were collected from the offshore area of Hainan Province. PCR and cloning techniques were used to clone and purify the mtDNA D-loop sequences of C. undu/atus populations （n =25）, about 1 400 bp long PCR product was obtained. ClustalX software was adopted for sequence alignment, and results were imported into MEGAS. 0. [ Result] According to experimental results, 66 mutation sites were detected from 25 individuals, including 0 deletion, 4 inserts, 59 transition sites, 2 transversion sites and 1 transition-transversion site. Pairwise genetic distances of these 25 individuals were calcu- lated by using MEGA5.0 software. Based on that, NJ phylogenetic tree of these 25 individuals was constructed. Analysis of C. undulatus populations using DNASP software showed that the polymorphic site number （S） was 62, nucleotide diversity （Pi） was 0.006 06, and average number of nucleotide differences （K） was 6. 907. [ Conclusion] Overall, there was no significant variation among mtDNA D-loops of C. undulatus populations. Key words
基金supported by National Key Research and Development Program of China(No.2018YFB0606104).
文摘The coupled CFD-DEM method with the JKR(Johnson-Kendall-Roberts)model for describing the contact adhesion of dust to filter particles(FPs)is used to simulate the distribution pattern of dust particle deposition in the granular bed filter(GBF)with multi-layer media.The minimum inlet flow velocity must meet the requirement that the contact probability between dust and FPs is in the high contact probability region.The air flow forms vortices on the leeward side of the FPs and changes abruptly at the intersection of different particle size FPs layers.Dust particles form large deposits at the intersection of the first and second layers and the different particle size filter layers.Dual element multilayer GBF can further optimize the bed structure by interlacing filter layers with different particle sizes.Compared with single particle size multi-layer GBF,the bed pressure drop is reduced by 40.24%-50.65%and the dust removal efficiency is increased by 21.93%-55.09%.
基金This work was funded by the National Key Research and Development Program of China(Fund project No.2018YFB0605901).
文摘Filtration tests were conducted on a granular bed filter with layered drawers filled with corundum particles with sizes between either 1 mm and 1.5 mm or 2 mm and 3 mm or with quartz sand particles with sizes between 0.125 mm and 1.5 mm.Filtration velocity,filter particle thickness,and filter particle size were all found to influence the filtration efficiency and the pressure drop of both the fixed granular bed and the layered-drawer granular bed.Granular strata with different thickness ratios also strongly influenced the filtration efficiency and pressure drop.For a granular bed with two sizes of filter particles,the coarse granules in the upper layer capture dust with large particle sizes,while the fine granules in the lower layer capture dust with smaller particle sizes that passes through the filter cake and upper layer.Optimal operating conditions were determined at which the filtration efficiency was found to be 99.42%with a bed pressure drop of 320 Pa.
基金the support of the National Key Research and Development Program of China(2018YFB0605903)for this study.
文摘The filtration of mixed dust that included a small number of melted(liquid)particles was studied in an experimental granular bed filter(GBF).Results show that the collection efficiency of dust containing melted particles is higher than that of dust composed of solid particles but the pressure drop from the former is higher than that of the latter.The collection efficiency and pressure drop increase as the concentration of melted particles increases.A surface sliding GBF exhibits good comprehensive performance when filtering dust,especially dust containing a mix of solid and liquid particles.The effects of the gas temperature,gas velocity,sliding filter bed thickness,and sliding collector flux on filter performance were also examined.Based on the experimental results,correlations for the collection efficiency and pressure drop for mixed dust are presented.
基金support of the National Key Research and Development Program of China(grant No.2018YFB0605903)to this study.
文摘Granular bed filters can effectively filter adhesive dust in high-temperature flue gas.In this study.polyvinyl chloride(PVC)powder was used as adhesive dust,and the mixture of PVC and ash powder was used to simulate solid and adhesive mixed dust.The effects of gas temperature,velocity,and inlet adhesive dust mass content on dust distribution in granular bed(GBF)were discussed.Results show that the mixed dust mainly accumulates on the upper part of the granular bed,and the mass of the collected dust decreases exponentially from the upper layer to the bottom layer in the GBF.The adhesive dust content collected in each layer differs from that of the incoming dust,and their deviation varies approximately linearly along with the depth of the bed.The total dust distribution and adhesive dust content deviation are influenced by gas temperature and inlet adhesive dust content but independent of gas velocity.The correlations of dust distribution of solid and adhesive mixed dust are presented based on the experimental results.
基金the support of the National Key Research and Development Program of China(grant No.2018YFB0605903).
文摘The effects of the filtering granule particle size and filtration superficial velocity on the dust particle size distribution in different layers of a granular bed system are discussed herein.A multilayer drawer granular bed filtration system was designed for these experiments based on filtering fly ash from a power plant.After a 1-h experiment,47.8% of dust particles smaller than 2.5μm,63.7% of dust particles smaller than 10μm,and 39.1% of dust particles larger than 10μm were captured by the granular bed(corresponding to initial volume fractions of 6%,19.3%,and 80.7%,respectively).Large dust particles were more easily trapped by the granular bed than small dust particles.Increasing the size of the filter granules and increasing the superficial velocity of the inlet flue gas were both effective ways to enhance the dust-holding capacity of the granular media throughout the granular bed.
基金financially supported by National Key Research and Development Program of China(No.2018YFB0606104)City University of Hong Kong Donation Research Grant(DON-RMG No.9229021)Shenzhen-Hong Kong Innovative Collaborative Research and Development Program(SGLH20181109110802117 and CityU 9240014).
文摘In order to limit global warming to 2°C,countries have adopted carbon capture and storage(CCS)technologies to reduce greenhouse gas emission.However,it is currently facing challenges such as controversial investment costs,unclear policies,and reduction of new energy power generation costs.In particular,some CCS projects are at a standstill.To promote the development of CCS projects in different countries,this paper reviews and compares energy conservation and emission reduction policies and different national goals.From a policy perspective,CCS-driven policies are analyzed.Based on this,corresponding policy recommendations are put forward,in order to promote the healthy development of global CCS technology and deal with climate issues more effectively.With less than 10 years away from the short-term goal,promoting the development and application of CCS projects requires scientific research from universities,enterprises and governments in order to attain zero or negative CO_(2)emission.On the basis of focusing on the development of CCS technology,according to the actual situation of each country,the appropriate application of CCS engineering should focus on the development of science and technology,rather than a unified requirement around the world.
