Lacustrine shale oil and gas are important fields for unconventional exploration and development in China,and organic-rich shale deposition lays down the critical foundation for hydrocarbon generation.There are two se...Lacustrine shale oil and gas are important fields for unconventional exploration and development in China,and organic-rich shale deposition lays down the critical foundation for hydrocarbon generation.There are two sets of shale,the Dongyuemiao and Da’anzhai Members,in the Ziliujing Formation in the Sichuan Basin.To identify the differential enrichment characteristics of organic matter and clarify its controlling factors,geochemical analyses of organic and inorganic geochemical analyses were performed.The results showed that the total organic carbon content of the Dongyuemiao shale(1.36%)is slightly higher than that of the Da’anzhai shale(0.95%).The enrichment of organic matter in the two shales resulted from the comprehensive controls of paleoproductivity,paleoenvironment,and terrigenous input,but different factors have different effects.In addition,driven by climate,the change in the sulfate concentration in the bottom water further led to the different intensities of bacterial sulfate reduction in early diagenesis.This made a great difference regarding organic matter accumulation in the two members.In general,climate may have played a dominant role in organic matter enrichment in the two sets of shale.展开更多
Objective Shale gas is as an important kind of unconventional natural gas,with a great resource potential,and its exploration and development has attracted much attention around the world.Organic matter(OM)pores are...Objective Shale gas is as an important kind of unconventional natural gas,with a great resource potential,and its exploration and development has attracted much attention around the world.Organic matter(OM)pores are a common constituent in shales and form the dominant pore network of many shale gas systems.展开更多
Support vector regression (SVR) combined with particle swarm optimization for its parameter optimization is employed to establish a model for predicting the Henry constants of multi-walled carbon nanotubes (MWNTs)...Support vector regression (SVR) combined with particle swarm optimization for its parameter optimization is employed to establish a model for predicting the Henry constants of multi-walled carbon nanotubes (MWNTs) for adsorption of volatile organic compounds (VOCs). The prediction performance of SVR is compared with those of the model of theoretical linear salvation energy relationship (TLSER). By using leave-one-out cross validation of SVR test Henry constants for adsorption of 35 VOCs on MWNTs, the root mean square error is 0.080, the mean absolute percentage error is only 1.19~, and the correlation coefficient (R2) is as high as 0.997. Compared with the results of the TLSER model, it is shown that the estimated errors by SVR are ali smaller than those achieved by TLSER. It reveals that the generalization ability of SVR is superior to that of the TLSER model Meanwhile, multifactor analysis is adopted for investigation of the influences of each molecular structure descriptor on the Henry constants. According to the TLSER model, the adsorption mechanism of adsorption of carbon nanotubes of VOCs is mainly a result of van der Waals and interactions of hydrogen bonds. These can provide the theoretical support for the application of carbon nanotube adsorption of VOCs and can make up for the lack of experimental data.展开更多
Most multicellular organisms can be categorised by two words: hierarchy and composite. The underlying fractal geometry of nature - at least in terms of provision of infrastructure - provides much of the hierarchy, al...Most multicellular organisms can be categorised by two words: hierarchy and composite. The underlying fractal geometry of nature - at least in terms of provision of infrastructure - provides much of the hierarchy, although many materials for which infrastructure is not an integral factor are also strongly hierarchical. Plants can therefore be modelled using recursive computer programs which add structures as the size increases. However, problems with mechanical stability also increase as the structure grows, so the plant changes from deriving stiffness from intevaal pressure to cross-linking the cell wall components permanently. However, this compromises the ability of the plant to grow and repair itself.展开更多
Recently,significant research has been conducted on the conversion of carbon dioxide(CO_(2))into value-added chemicals.With the decreasing cost of clean electricity,electrochemical methods have emerged as potential ap...Recently,significant research has been conducted on the conversion of carbon dioxide(CO_(2))into value-added chemicals.With the decreasing cost of clean electricity,electrochemical methods have emerged as potential approaches for converting and fixing CO_(2).Organic electrochemical synthesis is a promising method for utilizing CO_(2)because it transforms CO_(2)into higher-value chemicals.This review introduces the research aspects of CO_(2)conversion and the mechanisms of CO_(2)organic electrocarboxylation reactions.Recent progress in electrocarboxylation with CO_(2)is discussed,considering organic substrates and cathode types under different reaction mechanisms.Finally,the challenges and prospects in this field are highlighted with the aim of further promoting the fundamental understanding of CO_(2)organic electrocarboxylation.展开更多
Dissolved organic matter(DOM) is ubiquitous in the environment and has high reactivity.Once engineered nanoparticles(ENPs) are released into natural systems, interactions of DOM with ENPs may significantly affect ...Dissolved organic matter(DOM) is ubiquitous in the environment and has high reactivity.Once engineered nanoparticles(ENPs) are released into natural systems, interactions of DOM with ENPs may significantly affect the fate and transport of ENPs, as well as the bioavailability and toxicity of ENPs to organisms. However, because of the complexity of DOM and the shortage of useful characterization methods, large knowledge gaps exist in our understanding of the interactions between DOM and ENPs. In this article, we systematically reviewed the interactions between DOM and ENPs, discussed the effects of DOM on the environmental behavior of ENPs, and described the changes in bioavailability and toxicity of ENPs caused by DOM. Critical evaluations of published references suggest further need for assessing and predicting the influences of DOM on the transport,transformation, bioavailability, and toxicity of ENPs in the environment.展开更多
In recent years, many industrial enterprises located in the urban centers of China have been relocated owing to the rapid increase in urban development. At the sites abandoned by these enterprises, volatile organic co...In recent years, many industrial enterprises located in the urban centers of China have been relocated owing to the rapid increase in urban development. At the sites abandoned by these enterprises, volatile organic compounds have frequently been detected, sometimes at high concentrations, particularly at sites abandoned by chemical manufacturing enterprises. With the redevelopment of sites and changes in land-use tvpe associated with these sites, substantial amounts of contaminated soils now require remediation. "Since China is a developing country, soil remediation warrants the usage of techniques that are suitable for addressing the unique challenges faced in this country. Land shortage is a common problem in China; the large numbers of contaminated sites, tight development schedules, and limited financial resources necessitate the development of .cost-effective methods for land reclamation.Mechanical soil aeration is a simple, effective, and low-cost soil remediation tectm^que mat is particularly suitable for the remediation of large volatile organic compound-contaminated sites. Its effectiveness has been confirmed by conducting laboratory studies, pilot tests, and full-scale projects.This study reviews current engineei-ing practice and developmental trends of mechanical soil aeration and analyzes the advantages and disadvantages of this technology for application in China as an emerging soil remediation market. The findings of this study might aid technology development in China, as well as assist other developing countries in the assessment and implementation of costeffective hazardous waste site soil remediation programs.展开更多
基金This work was funded by the National Natural Science Foundation of China(Grant No.42002139 and U20B6001)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA14010404).
文摘Lacustrine shale oil and gas are important fields for unconventional exploration and development in China,and organic-rich shale deposition lays down the critical foundation for hydrocarbon generation.There are two sets of shale,the Dongyuemiao and Da’anzhai Members,in the Ziliujing Formation in the Sichuan Basin.To identify the differential enrichment characteristics of organic matter and clarify its controlling factors,geochemical analyses of organic and inorganic geochemical analyses were performed.The results showed that the total organic carbon content of the Dongyuemiao shale(1.36%)is slightly higher than that of the Da’anzhai shale(0.95%).The enrichment of organic matter in the two shales resulted from the comprehensive controls of paleoproductivity,paleoenvironment,and terrigenous input,but different factors have different effects.In addition,driven by climate,the change in the sulfate concentration in the bottom water further led to the different intensities of bacterial sulfate reduction in early diagenesis.This made a great difference regarding organic matter accumulation in the two members.In general,climate may have played a dominant role in organic matter enrichment in the two sets of shale.
基金supported by the National Natural Science Foundation of China(grant No.41202103)China Postdoctoral Science Foundation(grant No. 2016M591350)
文摘Objective Shale gas is as an important kind of unconventional natural gas,with a great resource potential,and its exploration and development has attracted much attention around the world.Organic matter(OM)pores are a common constituent in shales and form the dominant pore network of many shale gas systems.
基金Supported by the Innovative Talent Funds for Project 985 under Grant No WLYJSBJRCTD201102the Fundamental Research Funds for the Central Universities under Grant No CQDXWL-2013-014+1 种基金the Natural Science Foundation of Chongqing under Grant No CSTC2006BB5240the Program for New Century Excellent Talents in Universities of China under Grant No NCET-07-0903
文摘Support vector regression (SVR) combined with particle swarm optimization for its parameter optimization is employed to establish a model for predicting the Henry constants of multi-walled carbon nanotubes (MWNTs) for adsorption of volatile organic compounds (VOCs). The prediction performance of SVR is compared with those of the model of theoretical linear salvation energy relationship (TLSER). By using leave-one-out cross validation of SVR test Henry constants for adsorption of 35 VOCs on MWNTs, the root mean square error is 0.080, the mean absolute percentage error is only 1.19~, and the correlation coefficient (R2) is as high as 0.997. Compared with the results of the TLSER model, it is shown that the estimated errors by SVR are ali smaller than those achieved by TLSER. It reveals that the generalization ability of SVR is superior to that of the TLSER model Meanwhile, multifactor analysis is adopted for investigation of the influences of each molecular structure descriptor on the Henry constants. According to the TLSER model, the adsorption mechanism of adsorption of carbon nanotubes of VOCs is mainly a result of van der Waals and interactions of hydrogen bonds. These can provide the theoretical support for the application of carbon nanotube adsorption of VOCs and can make up for the lack of experimental data.
文摘Most multicellular organisms can be categorised by two words: hierarchy and composite. The underlying fractal geometry of nature - at least in terms of provision of infrastructure - provides much of the hierarchy, although many materials for which infrastructure is not an integral factor are also strongly hierarchical. Plants can therefore be modelled using recursive computer programs which add structures as the size increases. However, problems with mechanical stability also increase as the structure grows, so the plant changes from deriving stiffness from intevaal pressure to cross-linking the cell wall components permanently. However, this compromises the ability of the plant to grow and repair itself.
基金supported by the National Natural Science Foundation of China(22379054)and start-up funding from Jiangnan University.
文摘Recently,significant research has been conducted on the conversion of carbon dioxide(CO_(2))into value-added chemicals.With the decreasing cost of clean electricity,electrochemical methods have emerged as potential approaches for converting and fixing CO_(2).Organic electrochemical synthesis is a promising method for utilizing CO_(2)because it transforms CO_(2)into higher-value chemicals.This review introduces the research aspects of CO_(2)conversion and the mechanisms of CO_(2)organic electrocarboxylation reactions.Recent progress in electrocarboxylation with CO_(2)is discussed,considering organic substrates and cathode types under different reaction mechanisms.Finally,the challenges and prospects in this field are highlighted with the aim of further promoting the fundamental understanding of CO_(2)organic electrocarboxylation.
基金supported by the National Key Research and Development Program of China (2016YFA0203102)the National Natural Science Foundation of China (Nos. 21227012, 21337004, 21507147)
文摘Dissolved organic matter(DOM) is ubiquitous in the environment and has high reactivity.Once engineered nanoparticles(ENPs) are released into natural systems, interactions of DOM with ENPs may significantly affect the fate and transport of ENPs, as well as the bioavailability and toxicity of ENPs to organisms. However, because of the complexity of DOM and the shortage of useful characterization methods, large knowledge gaps exist in our understanding of the interactions between DOM and ENPs. In this article, we systematically reviewed the interactions between DOM and ENPs, discussed the effects of DOM on the environmental behavior of ENPs, and described the changes in bioavailability and toxicity of ENPs caused by DOM. Critical evaluations of published references suggest further need for assessing and predicting the influences of DOM on the transport,transformation, bioavailability, and toxicity of ENPs in the environment.
文摘In recent years, many industrial enterprises located in the urban centers of China have been relocated owing to the rapid increase in urban development. At the sites abandoned by these enterprises, volatile organic compounds have frequently been detected, sometimes at high concentrations, particularly at sites abandoned by chemical manufacturing enterprises. With the redevelopment of sites and changes in land-use tvpe associated with these sites, substantial amounts of contaminated soils now require remediation. "Since China is a developing country, soil remediation warrants the usage of techniques that are suitable for addressing the unique challenges faced in this country. Land shortage is a common problem in China; the large numbers of contaminated sites, tight development schedules, and limited financial resources necessitate the development of .cost-effective methods for land reclamation.Mechanical soil aeration is a simple, effective, and low-cost soil remediation tectm^que mat is particularly suitable for the remediation of large volatile organic compound-contaminated sites. Its effectiveness has been confirmed by conducting laboratory studies, pilot tests, and full-scale projects.This study reviews current engineei-ing practice and developmental trends of mechanical soil aeration and analyzes the advantages and disadvantages of this technology for application in China as an emerging soil remediation market. The findings of this study might aid technology development in China, as well as assist other developing countries in the assessment and implementation of costeffective hazardous waste site soil remediation programs.