[Objective] The control effect of floating plants constructed wetland to nitrogen and phosphorus pollution from rice field drainage was studied.[Method] Firstly,the characteristic of floating plants and the purificati...[Objective] The control effect of floating plants constructed wetland to nitrogen and phosphorus pollution from rice field drainage was studied.[Method] Firstly,the characteristic of floating plants and the purification principle of pollutants were introduced,and then purification effect was analyzed through controlling nitrogen and phosphorus pollution from rice field drainage by floating plants constructed wetland.[Result] By means of floating plants constructed wetland,the average removal rate of total nitrogen(TN) from double-season early and late rice field drainage reached 52.17% and 62.23%,respectively,while that of total phosphorus(TP) was 45.69% and 74.37%,respectively,with better removal effect.Meanwhile,floating plants have ecological and ornamental value to some extent.[Conclusion] Floating plants constructed wetland could not only control nitrogen and phosphorus pollution in field drainage effectively but also keep farmland ecosystem in healthy state.展开更多
With the construction of new countryside and the development of people's living standard,the environmental problems caused by rural domestic sewage gradually attracts more attention. Ecological floating bed is one...With the construction of new countryside and the development of people's living standard,the environmental problems caused by rural domestic sewage gradually attracts more attention. Ecological floating bed is one of the effective techniques for treating rural domestic sewage. Building different types of ecological floating beds according to the surrounding environment characteristics in rural areas could treat rural domestic sewage with low operation cost,simple management and convenient maintenance,and could obtain a certain economic benefit as well. Therefore,ecological floating bed get fast development in treating rural domestic sewage. The screening of plants would be vital as an important role. Assembling different plants by choosing those with ornamental function,economic benefit and strong decontamination ability according to the surrounding environment and characteristics of domestic waste water along with the seasonal features of plant growth could take full advantages of ecological floating bed.展开更多
This study presents a probabilistic safety analysis(PSA)method for the external event of extreme snowfall on a floating nuclear power plant(FNPP)deployed in the Bohai Sea.We utilized the Weibull and Gumbel extreme val...This study presents a probabilistic safety analysis(PSA)method for the external event of extreme snowfall on a floating nuclear power plant(FNPP)deployed in the Bohai Sea.We utilized the Weibull and Gumbel extreme value distributions to fit the collected meteorological data and obtained a hazard curve for the event of an extreme snowfall where the FNPP is located,providing a basis for the frequency of extreme snowfall-initiating events.Our analysis indicates that extreme snowfall primarily affects the ventilation openings of the equipment,leading to the failure of devices such as the diesel generators.Additionally,extreme snowfall can result in a loss of off-site power(LOOP).Therefore,the developed extreme snowfall PSA model is mainly based on the LOOP event tree,considering responses such as snowfall removal by personnel.Our calculations indicate a core damage frequency(CDF)of 1.13×10^(-10) owing to extreme snowfall,which is relatively low.The results of the cut-set analysis indicate that valve failures in the core makeup tank(CMT),passive residual heat removal system(PRS),and in-containment refueling water storage tank(IRWST)significantly contribute to the CDF.展开更多
Using Ecological Floating Bed (EFB) to purify polluted water is a process of ecological restoration at virgin position, as well as a complicated physical, chemical and biological process. Its core is utilizing aquatic...Using Ecological Floating Bed (EFB) to purify polluted water is a process of ecological restoration at virgin position, as well as a complicated physical, chemical and biological process. Its core is utilizing aquatic plants and root’s microbes to absorb nitrogen and phosphorus elements, degrade organic matter and enrich heavy metal. EFB has been applied to some water pollution control projects at home and abroad, and has got several achievements. However, there are some factors influenced the removal rate of pollutants, including plants, temperature, seasons, processing time, coverage and initial concentration of pollutants. In the future, the development orientation has been prospected from plant and its combinations, the transformation of EFB structure and the utilization of aquatic resources, and probed the technology of EFB’s building and management, to implement the win-win of landscape benefit and ecological function.展开更多
Floating flower art belongs to a category of embossing art,which is a kind of garden art that makes plant materials into flower decorations after treatment.In this paper,the whole technological process of making float...Floating flower art belongs to a category of embossing art,which is a kind of garden art that makes plant materials into flower decorations after treatment.In this paper,the whole technological process of making floating flower products was described in detail,and the unique manufacturing process of Japanese embossing brand "Sola Cube" was analyzed,in order to provide some theoretical reference for floating flower lovers and promote its development in China.展开更多
Wetlands are one of the important natural sources of atmospheric methane (CH_4),as an important part of wetlands,floating plants can be expected to affect methane release.However,the effects of floating plants on meth...Wetlands are one of the important natural sources of atmospheric methane (CH_4),as an important part of wetlands,floating plants can be expected to affect methane release.However,the effects of floating plants on methane release are limited.In this study,methane fluxes,physiochemical properties of the overlying water,methane oxidation potential and rhizospheric bacterial community were investigated in simulated wetlands with floating plants Eichhornia crassipes,Hydrocharis dubia,and Trapa natans.We found that E.crassipes,H.dubia,and T.natans plants could inhibit 84.31%-97.31%,4.98%-88.91%and 43.62%-92.51%of methane fluxes at interface of water-atmosphere compared to Control,respectively.Methane fluxes were negatively related to nutrients concentration in water column but positively related to the aerenchyma proportions of roots,stems,and leaves.At the same biomass,root of E.crassipes (36.44%) had the highest methane oxidation potential,followed by H.dubia (12.99%) and T.natans (11.23%).Forty-five bacterial phyla in total were identified on roots of three plants and 7 bacterial genera (2.10%-3.33%) were known methanotrophs.Type I methanotrophs accounted for 95.07%of total methanotrophs.The pmoA gene abundances ranged from 1.90×10^(16)to 2.30×10^(18)copies/g fresh weight of root biofilms.Abundances of pmoA gene was significantly positively correlated with environmental parameters.Methylotrophy (5.40%) and methanotrophy (3.75%) function were closely related to methane oxidation.This study highlights that floating plant restoration can purify water and promote carbon neutrality partially by reducing methane fluxes through methane oxidation in wetlands.展开更多
The Floating nuclear power plant grid is composed of power generation,in-station power supply and external power delivery.To ensure the safety of the nuclear island,the in-station system adopts a special power supply ...The Floating nuclear power plant grid is composed of power generation,in-station power supply and external power delivery.To ensure the safety of the nuclear island,the in-station system adopts a special power supply mode,while the external power supply needs to be adapted to different types of external systems.Because of frequent single phase-ground faults and various fault forms,the fault line selection protection should be accurate,sensitive and adaptive.This paper presents a fault line selection method in cooperation with multi-mode grounding control.Based on the maximum united energy entropy ratio(MUEER),the optimal wavelet basis function and decomposition scale are adaptively chosen,while the fault line is selected by wavelet transform modulus maxima(WTMM).For high-impedance faults(HIFs),to enlarge the fault feature,the system grounding mode can be switched by the multi-mode grounding control.Based on the characteristic of HIFs,the fault line can be selected by comparing phase differences of zero-sequence current mutation and fault phase voltage mutation before and after the fault.Simulation results using MATLAB/Simulink show the effectiveness of the proposed method in solving the protection problems.展开更多
Inland floating photovoltaic power plants(IFPPPs)are the key to making full use of water advantages to develop solar resources in the future.Identifying the investment risk is an important prerequisite for promoting t...Inland floating photovoltaic power plants(IFPPPs)are the key to making full use of water advantages to develop solar resources in the future.Identifying the investment risk is an important prerequisite for promoting the projects on a large scale.This paper proposes a model to assess the investment risk of IFPPPs in China.First,this paper identifies the investment risk factors and establishes an evaluation indicator system from four aspects.Second,the indicator data are collected and described by adopting hesitant fuzzy linguistic term sets and triangular fuzzy numbers to ensure soundness and completeness.Third,a weighted method combining the best-worst method and the entropy method are utilized to determine the indicator weights under the consideration of the impact of subjective preferences and objective fairness.Fourth,the results show that the overall risk level of China’s IFPPPs is‘medium low’.Fifth,sensitivity analysis and comparative analysis are implemented to examine the stability of the evaluation results.Finally,this paper also provides some risk-response strategies for the development of China’s IFPPPs from economy,society,technology and environment.展开更多
基金Supported by Natural Science Foundation of Guangxi Province(0991026)Foundation of Guangxi Key Laboratory of Environmental Engineering and Protection Assessment(0701K019)+1 种基金Project of Environmental Engineering Innovation Team of Talent Small Upland Construction in Universities in Guangxi([2007]Number71)InnovationProgram Project of Postgraduate Education in Guangxi Province(2009105960815M25)~~
文摘[Objective] The control effect of floating plants constructed wetland to nitrogen and phosphorus pollution from rice field drainage was studied.[Method] Firstly,the characteristic of floating plants and the purification principle of pollutants were introduced,and then purification effect was analyzed through controlling nitrogen and phosphorus pollution from rice field drainage by floating plants constructed wetland.[Result] By means of floating plants constructed wetland,the average removal rate of total nitrogen(TN) from double-season early and late rice field drainage reached 52.17% and 62.23%,respectively,while that of total phosphorus(TP) was 45.69% and 74.37%,respectively,with better removal effect.Meanwhile,floating plants have ecological and ornamental value to some extent.[Conclusion] Floating plants constructed wetland could not only control nitrogen and phosphorus pollution in field drainage effectively but also keep farmland ecosystem in healthy state.
基金Supported by National Natural Science Foundation of China(41263006,41661019,2014BAC04B02,21567010)Project of Department of Science and Technology of Jiangxi Province(20124ACB01200,20122BBG70086,20142BCB24009)Project of Jiangxi Academy of Sciences(GKKZ(2013)19-06,2016-YCXY-04,2013-XTPH1-14,2013H003)
文摘With the construction of new countryside and the development of people's living standard,the environmental problems caused by rural domestic sewage gradually attracts more attention. Ecological floating bed is one of the effective techniques for treating rural domestic sewage. Building different types of ecological floating beds according to the surrounding environment characteristics in rural areas could treat rural domestic sewage with low operation cost,simple management and convenient maintenance,and could obtain a certain economic benefit as well. Therefore,ecological floating bed get fast development in treating rural domestic sewage. The screening of plants would be vital as an important role. Assembling different plants by choosing those with ornamental function,economic benefit and strong decontamination ability according to the surrounding environment and characteristics of domestic waste water along with the seasonal features of plant growth could take full advantages of ecological floating bed.
文摘This study presents a probabilistic safety analysis(PSA)method for the external event of extreme snowfall on a floating nuclear power plant(FNPP)deployed in the Bohai Sea.We utilized the Weibull and Gumbel extreme value distributions to fit the collected meteorological data and obtained a hazard curve for the event of an extreme snowfall where the FNPP is located,providing a basis for the frequency of extreme snowfall-initiating events.Our analysis indicates that extreme snowfall primarily affects the ventilation openings of the equipment,leading to the failure of devices such as the diesel generators.Additionally,extreme snowfall can result in a loss of off-site power(LOOP).Therefore,the developed extreme snowfall PSA model is mainly based on the LOOP event tree,considering responses such as snowfall removal by personnel.Our calculations indicate a core damage frequency(CDF)of 1.13×10^(-10) owing to extreme snowfall,which is relatively low.The results of the cut-set analysis indicate that valve failures in the core makeup tank(CMT),passive residual heat removal system(PRS),and in-containment refueling water storage tank(IRWST)significantly contribute to the CDF.
文摘Using Ecological Floating Bed (EFB) to purify polluted water is a process of ecological restoration at virgin position, as well as a complicated physical, chemical and biological process. Its core is utilizing aquatic plants and root’s microbes to absorb nitrogen and phosphorus elements, degrade organic matter and enrich heavy metal. EFB has been applied to some water pollution control projects at home and abroad, and has got several achievements. However, there are some factors influenced the removal rate of pollutants, including plants, temperature, seasons, processing time, coverage and initial concentration of pollutants. In the future, the development orientation has been prospected from plant and its combinations, the transformation of EFB structure and the utilization of aquatic resources, and probed the technology of EFB’s building and management, to implement the win-win of landscape benefit and ecological function.
基金Sponsored by Provincial Innovation and Entrepreneurship Training Project for College Students in 2018(201812622013x)College Students’ Innovation and Entrepreneurship Training Project in 2017(CJDC2017045)
文摘Floating flower art belongs to a category of embossing art,which is a kind of garden art that makes plant materials into flower decorations after treatment.In this paper,the whole technological process of making floating flower products was described in detail,and the unique manufacturing process of Japanese embossing brand "Sola Cube" was analyzed,in order to provide some theoretical reference for floating flower lovers and promote its development in China.
基金supported by the National Natural Science Foundation of China (No. 51879084)the Technology Program for Water Pollution Control and Treatment of China (No. 2018ZX07208-004)。
文摘Wetlands are one of the important natural sources of atmospheric methane (CH_4),as an important part of wetlands,floating plants can be expected to affect methane release.However,the effects of floating plants on methane release are limited.In this study,methane fluxes,physiochemical properties of the overlying water,methane oxidation potential and rhizospheric bacterial community were investigated in simulated wetlands with floating plants Eichhornia crassipes,Hydrocharis dubia,and Trapa natans.We found that E.crassipes,H.dubia,and T.natans plants could inhibit 84.31%-97.31%,4.98%-88.91%and 43.62%-92.51%of methane fluxes at interface of water-atmosphere compared to Control,respectively.Methane fluxes were negatively related to nutrients concentration in water column but positively related to the aerenchyma proportions of roots,stems,and leaves.At the same biomass,root of E.crassipes (36.44%) had the highest methane oxidation potential,followed by H.dubia (12.99%) and T.natans (11.23%).Forty-five bacterial phyla in total were identified on roots of three plants and 7 bacterial genera (2.10%-3.33%) were known methanotrophs.Type I methanotrophs accounted for 95.07%of total methanotrophs.The pmoA gene abundances ranged from 1.90×10^(16)to 2.30×10^(18)copies/g fresh weight of root biofilms.Abundances of pmoA gene was significantly positively correlated with environmental parameters.Methylotrophy (5.40%) and methanotrophy (3.75%) function were closely related to methane oxidation.This study highlights that floating plant restoration can purify water and promote carbon neutrality partially by reducing methane fluxes through methane oxidation in wetlands.
基金Project Supported by National Natural Science Foundation of China(No.51877089).Research on the mechanism and fault ride-through integrated strategies of an active power router in hybrid AC and DC distribution grids.
文摘The Floating nuclear power plant grid is composed of power generation,in-station power supply and external power delivery.To ensure the safety of the nuclear island,the in-station system adopts a special power supply mode,while the external power supply needs to be adapted to different types of external systems.Because of frequent single phase-ground faults and various fault forms,the fault line selection protection should be accurate,sensitive and adaptive.This paper presents a fault line selection method in cooperation with multi-mode grounding control.Based on the maximum united energy entropy ratio(MUEER),the optimal wavelet basis function and decomposition scale are adaptively chosen,while the fault line is selected by wavelet transform modulus maxima(WTMM).For high-impedance faults(HIFs),to enlarge the fault feature,the system grounding mode can be switched by the multi-mode grounding control.Based on the characteristic of HIFs,the fault line can be selected by comparing phase differences of zero-sequence current mutation and fault phase voltage mutation before and after the fault.Simulation results using MATLAB/Simulink show the effectiveness of the proposed method in solving the protection problems.
基金supported by the Chinese Postdoctoral Science Foundation(2020M680488).
文摘Inland floating photovoltaic power plants(IFPPPs)are the key to making full use of water advantages to develop solar resources in the future.Identifying the investment risk is an important prerequisite for promoting the projects on a large scale.This paper proposes a model to assess the investment risk of IFPPPs in China.First,this paper identifies the investment risk factors and establishes an evaluation indicator system from four aspects.Second,the indicator data are collected and described by adopting hesitant fuzzy linguistic term sets and triangular fuzzy numbers to ensure soundness and completeness.Third,a weighted method combining the best-worst method and the entropy method are utilized to determine the indicator weights under the consideration of the impact of subjective preferences and objective fairness.Fourth,the results show that the overall risk level of China’s IFPPPs is‘medium low’.Fifth,sensitivity analysis and comparative analysis are implemented to examine the stability of the evaluation results.Finally,this paper also provides some risk-response strategies for the development of China’s IFPPPs from economy,society,technology and environment.
