At present, our country is paying more and more attention to environmental protection, and the treatment of various environmental pollution problems is becoming more and more standardized, especially the treatment of ...At present, our country is paying more and more attention to environmental protection, and the treatment of various environmental pollution problems is becoming more and more standardized, especially the treatment of air pollution problems. At the same time, we have formulated detailed management systems for exhaust emissions. Among the air pollution problems, the most serious one is the pollution of volatile organic compounds (VOCs), and the emission of VOCs in industrial production is particularly obvious. This is a kind of toxic gas, which can fuse with other polluting gases, thus causing compound pollution. Therefore, it is very necessary to study the treatment technology of VOCs in depth. The main purpose of this paper is to study the technology of treating VOCs waste, hoping to provide some valuable reference for the future improvement of air quality in our country.展开更多
In present work,the volatile constituents of Curcuma longa L.,A.lancea (Thunb.) DC.,Foeniculum vulgare Mill,and Cinnamomun cassia Presl.have been analyzed by flash distillation/capillary gas chro-matography/mass spect...In present work,the volatile constituents of Curcuma longa L.,A.lancea (Thunb.) DC.,Foeniculum vulgare Mill,and Cinnamomun cassia Presl.have been analyzed by flash distillation/capillary gas chro-matography/mass spectrometry.The results are consistent with those obtained by conventional steam distillation extraction method.The optimum condition of flash distillation has been studied.The experimental results showed that this new technique proved to be a simple,rapid and efficient tool for microanalysis of volatile constituents of Chinese medicinal herbs.展开更多
We present a new methodology to statistically determine the net present value(NPV)and internal rate of return(IRR)as financial estimators of shale gas investments.Our method allows us to forecast,in a fully probabilis...We present a new methodology to statistically determine the net present value(NPV)and internal rate of return(IRR)as financial estimators of shale gas investments.Our method allows us to forecast,in a fully probabilistic setting,financial performance risk and to understand the importance of the different factors that impact investment.The methodology developed in this study combines,through Monte Carlo simulation,the computational modeling of gas production from shale gas wells with a stochastic simulation of gas price as a geometric Brownian motion(GMB).To illustrate the methodology's validity,we apply it to an analysis of investments in shale gas wells.Our results show that gas price volatility is a key variable in the performance of an investment of this type,in such a way that at high volatilities,the potential return on an investment in shale gas increases significantly,but so do the risks of economic loss.This finding is consistent with the history of shale gas operations in which huge investment successes coexist with unexpected investment failures.展开更多
Porous flower-like SnO_(2)/CdSnO_(3) microstructures self-assembled by uniform nanosheets were synthesized using a hydrothermal process followed by calcination,and the sensing performance was measured when a gas senso...Porous flower-like SnO_(2)/CdSnO_(3) microstructures self-assembled by uniform nanosheets were synthesized using a hydrothermal process followed by calcination,and the sensing performance was measured when a gas sensor,based on such microstructures,was exposed to various volatile organic compound(VOC)gases.The response value was found to reach as high as 100.1 when the SnO_(2)/CdSnO_(3) sensor was used to detect 100 ppm formaldehyde gas,much larger than those of other tested VOC gases,indicating the high gas sensitivity possessed by this sensor especially in the detection of formaldehyde gas.Meanwhile,the response/recovery process was fast with the response time and recovery time of only 13 and 21 s,respectively.The excellent gas sensing performance derive from the advantages of SnO_(2)/CdSnO_(3),such as abundant n-n heterojunctions built at the interface,high available specific surface area,abundant porosity,large pore size,and rich reactive oxygen species,as well as joint effects arising from SnO_(2) and CdSnO_(3),suggesting that such porous flower-like SnO_(2)/CdSnO_(3) microstructures composed of nanosheets have a high potential for developing gas sensors.展开更多
文摘At present, our country is paying more and more attention to environmental protection, and the treatment of various environmental pollution problems is becoming more and more standardized, especially the treatment of air pollution problems. At the same time, we have formulated detailed management systems for exhaust emissions. Among the air pollution problems, the most serious one is the pollution of volatile organic compounds (VOCs), and the emission of VOCs in industrial production is particularly obvious. This is a kind of toxic gas, which can fuse with other polluting gases, thus causing compound pollution. Therefore, it is very necessary to study the treatment technology of VOCs in depth. The main purpose of this paper is to study the technology of treating VOCs waste, hoping to provide some valuable reference for the future improvement of air quality in our country.
文摘In present work,the volatile constituents of Curcuma longa L.,A.lancea (Thunb.) DC.,Foeniculum vulgare Mill,and Cinnamomun cassia Presl.have been analyzed by flash distillation/capillary gas chro-matography/mass spectrometry.The results are consistent with those obtained by conventional steam distillation extraction method.The optimum condition of flash distillation has been studied.The experimental results showed that this new technique proved to be a simple,rapid and efficient tool for microanalysis of volatile constituents of Chinese medicinal herbs.
基金partially funded by Goverment of Spain,Ministry of Science,Innovation and Universities(grant:RTI2018093366-B-I00)by Goverment of Spain,Ministry of Universities(grant:Subsidies to Public Universities for the Requalification of the Spanish University System,“Margarita Salas”Grants Modality for the Training of Young Doctors,RD 289/2021 of April 20)+1 种基金by the Xunta de Galicia,Consellería de Educacion e Ordenación Universitaria(grant:#ED431C 2018/41)by the Group of Numerical Methods in Engineering of the Universidade de A Coruna。
文摘We present a new methodology to statistically determine the net present value(NPV)and internal rate of return(IRR)as financial estimators of shale gas investments.Our method allows us to forecast,in a fully probabilistic setting,financial performance risk and to understand the importance of the different factors that impact investment.The methodology developed in this study combines,through Monte Carlo simulation,the computational modeling of gas production from shale gas wells with a stochastic simulation of gas price as a geometric Brownian motion(GMB).To illustrate the methodology's validity,we apply it to an analysis of investments in shale gas wells.Our results show that gas price volatility is a key variable in the performance of an investment of this type,in such a way that at high volatilities,the potential return on an investment in shale gas increases significantly,but so do the risks of economic loss.This finding is consistent with the history of shale gas operations in which huge investment successes coexist with unexpected investment failures.
基金financially supported by the National Research Foundation of Korea NRF-2019R1A5A8080290the National Natural Science Foundation of China(Grant No.52171148)the Natural Science Foundation of Anhui Province(Grant No.2008085J23).
文摘Porous flower-like SnO_(2)/CdSnO_(3) microstructures self-assembled by uniform nanosheets were synthesized using a hydrothermal process followed by calcination,and the sensing performance was measured when a gas sensor,based on such microstructures,was exposed to various volatile organic compound(VOC)gases.The response value was found to reach as high as 100.1 when the SnO_(2)/CdSnO_(3) sensor was used to detect 100 ppm formaldehyde gas,much larger than those of other tested VOC gases,indicating the high gas sensitivity possessed by this sensor especially in the detection of formaldehyde gas.Meanwhile,the response/recovery process was fast with the response time and recovery time of only 13 and 21 s,respectively.The excellent gas sensing performance derive from the advantages of SnO_(2)/CdSnO_(3),such as abundant n-n heterojunctions built at the interface,high available specific surface area,abundant porosity,large pore size,and rich reactive oxygen species,as well as joint effects arising from SnO_(2) and CdSnO_(3),suggesting that such porous flower-like SnO_(2)/CdSnO_(3) microstructures composed of nanosheets have a high potential for developing gas sensors.
