• Energy Research

La complejidad de la comunidad de vegetación es un factor crítico que influye en la estabilidad del ecosistema terrestre. China, el país que lidera el mundo en el reverdecimiento de la vegetación como resultado de las actividades humanas, ha experimentado cambios dramáticos en la composición de la comunidad de vegetación durante los últimos 30 años. Sin embargo, la forma en que la complejidad de la comunidad de vegetación de China varía espacial y temporalmente sigue sin estar clara. Aquí, proporcionamos los conjuntos de datos y códigos utilizados para investigar este tema, según lo publicado en "Human-climate coupled changes in vegetation community complexity of China since 1980s" por Su et al. La complexité de la communauté végétale est un facteur critique influençant la stabilité de l'écosystème terrestre. La Chine, le pays leader mondial en matière de verdissement de la végétation résultant des activités humaines, a connu des changements spectaculaires dans la composition des communautés végétales au cours des 30 dernières années. Cependant, la façon dont la complexité de la communauté végétale chinoise varie spatialement et temporellement reste incertaine. Ici, nous avons fourni les ensembles de données et les codes utilisés pour étudier cette question, tels que publiés dans « Human-climate coupled changes in vegetation community complexity of China since 1980s » par Su et al. Vegetation community complexity is a critical factor influencing terrestrial ecosystem stability. China, the country leading the world in vegetation greening resulting from human activities, has experienced dramatic changes in vegetation community composition during the past 30 years. However, how China's vegetation community complexity varies spatially and temporally remains unclear. Here, we provided the datasets and codes used to investigate this issue, as published in "Human-climate coupled changes in vegetation community complexity of China since 1980s" by Su et al. يعد تعقيد مجتمع الغطاء النباتي عاملاً حاسمًا يؤثر على استقرار النظام البيئي الأرضي. شهدت الصين، الدولة الرائدة في العالم في تخضير الغطاء النباتي الناتج عن الأنشطة البشرية، تغييرات جذرية في تكوين مجتمع الغطاء النباتي خلال الثلاثين عامًا الماضية. ومع ذلك، لا يزال من غير الواضح كيف يختلف تعقيد مجتمع الغطاء النباتي في الصين مكانيًا وزمنيًا. قدمنا هنا مجموعات البيانات والرموز المستخدمة للتحقيق في هذه المشكلة، كما نُشرت في "التغيرات المقترنة بالمناخ البشري في تعقيد مجتمع الغطاء النباتي في الصين منذ الثمانينيات" من قبل سو وآخرون.

La complejidad de la comunidad de vegetación es un factor crítico que influye en la estabilidad del ecosistema terrestre. China, el país que lidera el mundo en el reverdecimiento de la vegetación como resultado de las actividades humanas, ha experimentado cambios dramáticos en la composición de la comunidad de vegetación durante los últimos 30 años. Sin embargo, la forma en que la complejidad de la comunidad de vegetación de China varía espacial y temporalmente sigue sin estar clara. Aquí, proporcionamos los conjuntos de datos y códigos utilizados para investigar este tema, según lo publicado en "Human-climate coupled changes in vegetation community complexity of China since 1980s" por Su et al. La complexité de la communauté végétale est un facteur critique influençant la stabilité de l'écosystème terrestre. La Chine, le pays leader mondial en matière de verdissement de la végétation résultant des activités humaines, a connu des changements spectaculaires dans la composition des communautés végétales au cours des 30 dernières années. Cependant, la façon dont la complexité de la communauté végétale chinoise varie spatialement et temporellement reste incertaine. Ici, nous avons fourni les ensembles de données et les codes utilisés pour étudier cette question, tels que publiés dans « Human-climate coupled changes in vegetation community complexity of China since 1980s » par Su et al. Vegetation community complexity is a critical factor influencing terrestrial ecosystem stability. China, the country leading the world in vegetation greening resulting from human activities, has experienced dramatic changes in vegetation community composition during the past 30 years. However, how China's vegetation community complexity varies spatially and temporally remains unclear. Here, we provided the datasets and codes used to investigate this issue, as published in "Human-climate coupled changes in vegetation community complexity of China since 1980s" by Su et al. يعد تعقيد مجتمع الغطاء النباتي عاملاً حاسمًا يؤثر على استقرار النظام البيئي الأرضي. شهدت الصين، الدولة الرائدة في العالم في تخضير الغطاء النباتي الناتج عن الأنشطة البشرية، تغييرات جذرية في تكوين مجتمع الغطاء النباتي خلال الثلاثين عامًا الماضية. ومع ذلك، لا يزال من غير الواضح كيف يختلف تعقيد مجتمع الغطاء النباتي في الصين مكانيًا وزمنيًا. قدمنا هنا مجموعات البيانات والرموز المستخدمة للتحقيق في هذه المشكلة، كما نُشرت في "التغيرات المقترنة بالمناخ البشري في تعقيد مجتمع الغطاء النباتي في الصين منذ الثمانينيات" من قبل سو وآخرون.

In this work, plasma electrolytic technology was successfully employed to achieve fast liquefaction of sawdust when polyethylene glycol 200 (PEG 200) and glycerol were used as liquefacient in the presence of the catalyst sulfuric acid. Results showed that H ions could heat the solution effectively during the plasma electrolytic liquefaction (PEL) process. The influence of some key parameters including liquefaction time, catalyst percentage, liquefacient/sawdust mass ratio, and PEG 200/glycerol molar ratio on the liquefaction yield were investigated. Based on the results of single factor experiments, response surface methodology (RSM) was applied to optimize the liquefaction process. Under the optimal conditions that is liquefaction time of 5.10min, catalyst percentage of 1.05%, liquefacient/sawdust mass ratio of 7.12/1 and PEG 200/glycerol molar ratio of 1.40/1, the liquefaction yield reached 99.48%. Hence, it could be concluded that PEL has good application potential for biomass fast liquefaction.

In this work, plasma electrolytic technology was successfully employed to achieve fast liquefaction of sawdust when polyethylene glycol 200 (PEG 200) and glycerol were used as liquefacient in the presence of the catalyst sulfuric acid. Results showed that H ions could heat the solution effectively during the plasma electrolytic liquefaction (PEL) process. The influence of some key parameters including liquefaction time, catalyst percentage, liquefacient/sawdust mass ratio, and PEG 200/glycerol molar ratio on the liquefaction yield were investigated. Based on the results of single factor experiments, response surface methodology (RSM) was applied to optimize the liquefaction process. Under the optimal conditions that is liquefaction time of 5.10min, catalyst percentage of 1.05%, liquefacient/sawdust mass ratio of 7.12/1 and PEG 200/glycerol molar ratio of 1.40/1, the liquefaction yield reached 99.48%. Hence, it could be concluded that PEL has good application potential for biomass fast liquefaction.

In this research, we compared the discharge characteristics and catalytic efficiency of sulfuric acid, p-toluenesulfonic acid, and their respective sodium salts (sodium sulfate and sodium p-toluenesulfonate) in sawdust liquefaction and found that sulfuric acid was the optimal catalyst when glycerol was used as solvent during the plasma electrolytic liquefaction (PEL) process. When sodium p-toluenesulfonate was used as the only catalyst, the liquefaction yield reached 83.51% after 25 min. This yield was higher than that obtained using sodium sulfate as the catalyst (60.63%) because different concentrations of H ions were produced in PEL. Cellulose, lignin, and holocellulose were extracted from sawdust and successfully liquefied in PEL, illustrating the universality of PEL. The optical emission spectra of the different biomass during the PEL process were similar, indicating that the kinds of free radicals produced were similar, which can accelerate the liquefaction of sawdust.

In this research, we compared the discharge characteristics and catalytic efficiency of sulfuric acid, p-toluenesulfonic acid, and their respective sodium salts (sodium sulfate and sodium p-toluenesulfonate) in sawdust liquefaction and found that sulfuric acid was the optimal catalyst when glycerol was used as solvent during the plasma electrolytic liquefaction (PEL) process. When sodium p-toluenesulfonate was used as the only catalyst, the liquefaction yield reached 83.51% after 25 min. This yield was higher than that obtained using sodium sulfate as the catalyst (60.63%) because different concentrations of H ions were produced in PEL. Cellulose, lignin, and holocellulose were extracted from sawdust and successfully liquefied in PEL, illustrating the universality of PEL. The optical emission spectra of the different biomass during the PEL process were similar, indicating that the kinds of free radicals produced were similar, which can accelerate the liquefaction of sawdust.

This paper presents the flow characteristics in the fluid circulation system using an electromagnetic pump on a molten metal. The flow characteristics of molten metal are analyzed by coupling electromagnetic with Navier-Stokes equations. The analysis results will be compared with the result of the experiment.

This paper presents the flow characteristics in the fluid circulation system using an electromagnetic pump on a molten metal. The flow characteristics of molten metal are analyzed by coupling electromagnetic with Navier-Stokes equations. The analysis results will be compared with the result of the experiment.

Nanoparticles designed with high electric conductivity and magnetic permeability are injected into oil reservoir to enhance the tracking of the fluid movement. The injection of fluid with nanoparticles will displace the original fluid and change the fluid content in the pore space, thus changing the electric conductivity and magnetic permeability distributions in the flooded zone. The movement of nanoparticles in a porous medium can be modeled by solving the flow transport equation and the resultant electromagnetic properties distribution can be calculated by the effective medium theory. These inhomogeneous electromagnetic property distributions will induce secondary electromagnetic fields in the receivers which can be modeled by Maxwell's equations. For subsurface sensing, in order to be detected, the secondary fields measured in the receivers should be above a certain threshold (1% above the primary fields, an empirical value). By injecting the high contrast nanoparticles, the conductivity and magnetic permeability of the flooded zone will be increased, thus increasing the secondary fields which will be more possibly detected. Also the detection range of electromagnetic measurements will be larger. With the technique of coupling of the dynamic fluid flow and crosswell electromagnetic measurement, we are able to analyze the detection range of electromagnetic sensing with high contrast nanoparticle injection.