Natural gas methane and hydrates are a chemical compound of water molecules formed under low temperature and high pressure. The decomposition of 1 m^3 of natural gas hydrates can release about 0.8 m^3 of water and 164...Natural gas methane and hydrates are a chemical compound of water molecules formed under low temperature and high pressure. The decomposition of 1 m^3 of natural gas hydrates can release about 0.8 m^3 of water and 164 m3 of natural gas. Thus, natural gas hydrates are characterized by their high-energy density and huge resource potential. It is estimated that the world＇s total natural gas hydrates resource amount is equivalent to twice the total carbon amount of the global proven conventional fuels and can meet the human energy requirement in the future for 1000 years. They are thus the first choice to replace conventional energy of petroleum and coal.展开更多
The innovative city pilot policy(ICPP)is an essential manifestation of China’s construction of an innovative and green-driven development country.We incorporated urban green total factor productivity(GTFP)growth into...The innovative city pilot policy(ICPP)is an essential manifestation of China’s construction of an innovative and green-driven development country.We incorporated urban green total factor productivity(GTFP)growth into the evaluation of ICPP.Based on the panel data of 223 cities in China from 2005 to 2020,we used the difference-in-differences model to empirically assess the influence and mechanism of the ICPP on urban GTFP growth.The main results show that(i)The ICPP has maintained an effectively fluctuating promotion on urban GTFP growth,mainly manifested in the urban green technological progress improvement.(ii)The ICPP has urban heterogeneity in promoting GTFP growth in pilot cities,mainly affecting key cities such as provincial capitals.(iii)The interaction between the agglomeration of producer services and the ICPP inhibits GTFP growth in pilot cities.展开更多
Agricultural product price index insurance is a kind of index insurance. It avoids defects of traditional agricultural insurance,such as moral hazards,adverse selection,and high management cost. On the basis of studyi...Agricultural product price index insurance is a kind of index insurance. It avoids defects of traditional agricultural insurance,such as moral hazards,adverse selection,and high management cost. On the basis of studying agricultural product price index insurance of all areas of China,this paper analyzed characteristics of agricultural product price index insurance from object selection,product object,premium design,and policy support,and discussed feasibility of extending agricultural product price index insurance in an all-round way.展开更多
[Objectives]To study and optimize the process conditions of enzymatic hydrolysis technology for extracting polysaccharides from Pseudostellaria heterophylla fibrous roots and its application in workshop pilot tests.[M...[Objectives]To study and optimize the process conditions of enzymatic hydrolysis technology for extracting polysaccharides from Pseudostellaria heterophylla fibrous roots and its application in workshop pilot tests.[Methods]P.heterophylla fibrous roots were taken as the matrix material,and Box Behnken design was used to analyze the extraction time,composite enzyme addition amount,and liquid-solid ratio for response surface optimization experiments,and then applied to the pilot extraction of P.heterophylla fibrous roots.[Results]Response surface analysis showed that all factors had a significant impact on the experimental indicators.The optimal extraction process conditions for polysaccharides from P.heterophylla fibrous roots were extraction time of 2.7 h,compound enzyme addition of 2.5%,and liquid-solid ratio of 32.The yield of polysaccharides from P.heterophylla fibrous roots was 4.83%.The water extraction process of P.heterophylla fibrous roots extraction pilot was used as the control group for response surface optimization of the pilot experiment.The optimization results showed that the extraction time was 3 h,the amount of composite enzyme added was 2.5%,and the liquid-solid ratio was 28.The polysaccharide yield was 4.75%,an increase of 4.63%compared to the control group.[Conclusions]This paper could provide feasibility for the innovation of enzy-matic hydrolysis technology for P.heterophylla fibrous roots and its workshop pilot practice application,as well as a reference for the industrial application of its medicinal resources.展开更多
The potential for Monascus pigments(MPs)production in a mixture of Chinese rice wine lees,soaked rice wastewater and broken rice was explored.MPs production reached 120.1 U/mL with optimal solid-liquid ratio of cultur...The potential for Monascus pigments(MPs)production in a mixture of Chinese rice wine lees,soaked rice wastewater and broken rice was explored.MPs production reached 120.1 U/mL with optimal solid-liquid ratio of culture medium 1:10 and 20 g/L broken rice addition at shake flask level.We further explored the effects of stirring speed on MPs production in 7.5 L agitated bioreactor.The stirring speed had a great impact on cell morphology and the maximum MPs concentration and yield were 128.4 U/mL and 8174 U/g respectively at 400 rpm.The soluble chemical oxygen demand for the soaked rice wastewater decreased by 78.7%,which was mainly due to the intake of carbohydrates,organic acids and amino acids.Furthermore,a simultaneous fermentation process and production system with two-stage stirring speed control strategy was further developed in the 50 L pilot scale,in which the MPs production reached 158.9 U/mL.Meanwhile,Chinese rice wine wastes were fully utilized without addition of organic solvents during the process and no generation of new waste.Our results showed that Monascus was capable of converting Chinese rice wine wastes into natural pigments by submerged fermentation,which could provide an economic and environmentally friendly approach to reduce the cost of wastes treatment as well as high-value utilization.展开更多
Due to the characteristics of reservoir formation,the producing level of low permeability reservoir is relatively very low.It is hard to obtain high recovery through conventional development schemes.Considering the ti...Due to the characteristics of reservoir formation,the producing level of low permeability reservoir is relatively very low.It is hard to obtain high recovery through conventional development schemes.Considering the tight matrix,complex fracture system,low production level of producers,and low recovery factor ofMblock in Xinjiang oilfield,it is selected for on-site pilot test of nitrogen foam flooding.Detailed flooding scheme is made and the test results are evaluated respectively both for producers and injectors.The pressure index,filling degree,and fluid injection profile are found to be all improved in injectors after injection of nitrogen foam.The oil production,water cut and liquid production file are also improved in most of the producers,with the natural decline rate in the test area become slow.Results show that nitrogen foam flooding technology can be good technical storage for enhanced oil recovery in low permeability reservoir.展开更多
文摘Natural gas methane and hydrates are a chemical compound of water molecules formed under low temperature and high pressure. The decomposition of 1 m^3 of natural gas hydrates can release about 0.8 m^3 of water and 164 m3 of natural gas. Thus, natural gas hydrates are characterized by their high-energy density and huge resource potential. It is estimated that the world＇s total natural gas hydrates resource amount is equivalent to twice the total carbon amount of the global proven conventional fuels and can meet the human energy requirement in the future for 1000 years. They are thus the first choice to replace conventional energy of petroleum and coal.
基金Study on the Path of Promoting the Integration of“Three Societies”and Help Rural Revitalization in Chongqing,Chongqing Social Science Planning Office[Grant number.2019WT13]Study on the Cultivation of Language Service Talents Under the Background of Belt and Road Initiative,Chongqing Social Science Planning Office[Grant number.2021WYZX12].
文摘The innovative city pilot policy(ICPP)is an essential manifestation of China’s construction of an innovative and green-driven development country.We incorporated urban green total factor productivity(GTFP)growth into the evaluation of ICPP.Based on the panel data of 223 cities in China from 2005 to 2020,we used the difference-in-differences model to empirically assess the influence and mechanism of the ICPP on urban GTFP growth.The main results show that(i)The ICPP has maintained an effectively fluctuating promotion on urban GTFP growth,mainly manifested in the urban green technological progress improvement.(ii)The ICPP has urban heterogeneity in promoting GTFP growth in pilot cities,mainly affecting key cities such as provincial capitals.(iii)The interaction between the agglomeration of producer services and the ICPP inhibits GTFP growth in pilot cities.
基金Supported by the National Social Science Foundation of China(16BJY136) in 2016the Consultant Project of Chinese Academy of Engineering(07-XY-003) in 2015
文摘Agricultural product price index insurance is a kind of index insurance. It avoids defects of traditional agricultural insurance,such as moral hazards,adverse selection,and high management cost. On the basis of studying agricultural product price index insurance of all areas of China,this paper analyzed characteristics of agricultural product price index insurance from object selection,product object,premium design,and policy support,and discussed feasibility of extending agricultural product price index insurance in an all-round way.
基金Supported by Special Project of Central Leading Local Science and Technology Development(202113030)Regional Development Project of Fujian Provincial Science and Technology Plan(2022N3017).
文摘[Objectives]To study and optimize the process conditions of enzymatic hydrolysis technology for extracting polysaccharides from Pseudostellaria heterophylla fibrous roots and its application in workshop pilot tests.[Methods]P.heterophylla fibrous roots were taken as the matrix material,and Box Behnken design was used to analyze the extraction time,composite enzyme addition amount,and liquid-solid ratio for response surface optimization experiments,and then applied to the pilot extraction of P.heterophylla fibrous roots.[Results]Response surface analysis showed that all factors had a significant impact on the experimental indicators.The optimal extraction process conditions for polysaccharides from P.heterophylla fibrous roots were extraction time of 2.7 h,compound enzyme addition of 2.5%,and liquid-solid ratio of 32.The yield of polysaccharides from P.heterophylla fibrous roots was 4.83%.The water extraction process of P.heterophylla fibrous roots extraction pilot was used as the control group for response surface optimization of the pilot experiment.The optimization results showed that the extraction time was 3 h,the amount of composite enzyme added was 2.5%,and the liquid-solid ratio was 28.The polysaccharide yield was 4.75%,an increase of 4.63%compared to the control group.[Conclusions]This paper could provide feasibility for the innovation of enzy-matic hydrolysis technology for P.heterophylla fibrous roots and its workshop pilot practice application,as well as a reference for the industrial application of its medicinal resources.
基金This work was supported by the National Key Research and Development Program of China(2021YFC2104001,2022YFC2105501)the China Postdoctoral Science Foundation(2022M711368)+1 种基金the Fundamental Research Funds for the Central Universities(JUSRP122037)the Natural Science Foundation of Jiangsu Province,Science,and Technology Department of Jiangsu Province,China(BK20221081).
文摘The potential for Monascus pigments(MPs)production in a mixture of Chinese rice wine lees,soaked rice wastewater and broken rice was explored.MPs production reached 120.1 U/mL with optimal solid-liquid ratio of culture medium 1:10 and 20 g/L broken rice addition at shake flask level.We further explored the effects of stirring speed on MPs production in 7.5 L agitated bioreactor.The stirring speed had a great impact on cell morphology and the maximum MPs concentration and yield were 128.4 U/mL and 8174 U/g respectively at 400 rpm.The soluble chemical oxygen demand for the soaked rice wastewater decreased by 78.7%,which was mainly due to the intake of carbohydrates,organic acids and amino acids.Furthermore,a simultaneous fermentation process and production system with two-stage stirring speed control strategy was further developed in the 50 L pilot scale,in which the MPs production reached 158.9 U/mL.Meanwhile,Chinese rice wine wastes were fully utilized without addition of organic solvents during the process and no generation of new waste.Our results showed that Monascus was capable of converting Chinese rice wine wastes into natural pigments by submerged fermentation,which could provide an economic and environmentally friendly approach to reduce the cost of wastes treatment as well as high-value utilization.
基金supported by the Prospective and Fundamental Project of CNPC“Study on the EOR Technology by Foam Flooding(2021DJ1603)”by Open Fund of State Key Laboratory of Enhanced Oil Recovery,CNPC(2022-KFKT-29).
文摘Due to the characteristics of reservoir formation,the producing level of low permeability reservoir is relatively very low.It is hard to obtain high recovery through conventional development schemes.Considering the tight matrix,complex fracture system,low production level of producers,and low recovery factor ofMblock in Xinjiang oilfield,it is selected for on-site pilot test of nitrogen foam flooding.Detailed flooding scheme is made and the test results are evaluated respectively both for producers and injectors.The pressure index,filling degree,and fluid injection profile are found to be all improved in injectors after injection of nitrogen foam.The oil production,water cut and liquid production file are also improved in most of the producers,with the natural decline rate in the test area become slow.Results show that nitrogen foam flooding technology can be good technical storage for enhanced oil recovery in low permeability reservoir.
