With the newly proposed Global Ocean Observing Integration,ocean observing scope has been expanded from the region to the global,therefore the need of large-scale ocean observing system integration has become more and...With the newly proposed Global Ocean Observing Integration,ocean observing scope has been expanded from the region to the global,therefore the need of large-scale ocean observing system integration has become more and more urgent.Currently,ocean observing systems enabled ocean sensor networks are commonly developed by different organizations using specific technologies and platforms,which brings several challenges in ocean observing instrument(OOI) access and ocean observing system seamless integration.Furthermore,the development of ocean observing systems often suffers from low efficiency due to the complex programming and debugging process.To solve these problems,a novel model,Complex Virtual Instrument(CVI) Model,is proposed.The model provides formal definitions on observing instrument description file,CVI description file,model calculation method,development model and interaction standard.In addition,this model establishes mathematical expressions of two model calculation operations,meanwhile builds the mapping relationship between observing instrument description file and CVI description file.The CVI based on the new model can achieve automatic access to different OOIs,seamless integration and communication for heterogeneous environments,and further implement standardized data access and management for the global unified ocean observing network.Throughout the development,integration and application of such CVI,the rationality and feasibility of the model have been evaluated.The results confirm that the proposed model can effectively implement heterogeneous system integration,improve development efficiency,make full usage of reusable components,reduce development cost,and enhance overall software system quality.We believe that our new model has great significance to promote the large-scale ocean observing system integration.展开更多
The extremely high structural tolerance of ceria to oxygen vacancies(Ov)has made it a desirable catalytic material for the hydrocarbon oxidation to chemicals and pharmaceuticals and the reduction of gaseous pollutants...The extremely high structural tolerance of ceria to oxygen vacancies(Ov)has made it a desirable catalytic material for the hydrocarbon oxidation to chemicals and pharmaceuticals and the reduction of gaseous pollutants.It is proposed that the formation and diffusion of Ov originate from its outstanding reduction property.However,the formation and diffusion process of Ov over the surface of ceria at the atomic level is still unknown.Herein,the structural and valence evolution of CeO_(2)(111)surfaces in reductive,oxidative and vacuum environments from room temperature up to 700℃was studied with in situ aberration-corrected environmental transmission electron microscopy(ETEM)experiments.Ov is found to form under a high vacuum at elevated temperatures;however,the surface can recover to the initial state through the adsorption of oxygen atoms in an oxygen-contained environment.Furthermore,in hydrogen environment,the step-CeO_(2)(111)surface is not stable at elevated temperatures;thus,the steps tend to be eliminated with increasing temperature.Combined with first-principles density function calculations(DFT),it is proposed that O-terminated surfaces would develop in a hypoxic environment due to the dynamic diffusion of Ov from the outer surface to the subsurface.Furthermore,in a reductive environment,H2 facilitates the formation and diffusion of Ov while Ce-terminated surfaces develope.These results reveal dynamic atomic-scale interplay between the nanoceria surface and gas,thereby providing fundamental insights into the Ov-dependent reaction of nano-CeO_(2) during catalytic processes.展开更多
基金supported by the National Natural Science Foundation of China(Nos.41606112,61103196,61379127,61379128)the National High Technology Research and Development Program 863(No.2013AA09A506)
文摘With the newly proposed Global Ocean Observing Integration,ocean observing scope has been expanded from the region to the global,therefore the need of large-scale ocean observing system integration has become more and more urgent.Currently,ocean observing systems enabled ocean sensor networks are commonly developed by different organizations using specific technologies and platforms,which brings several challenges in ocean observing instrument(OOI) access and ocean observing system seamless integration.Furthermore,the development of ocean observing systems often suffers from low efficiency due to the complex programming and debugging process.To solve these problems,a novel model,Complex Virtual Instrument(CVI) Model,is proposed.The model provides formal definitions on observing instrument description file,CVI description file,model calculation method,development model and interaction standard.In addition,this model establishes mathematical expressions of two model calculation operations,meanwhile builds the mapping relationship between observing instrument description file and CVI description file.The CVI based on the new model can achieve automatic access to different OOIs,seamless integration and communication for heterogeneous environments,and further implement standardized data access and management for the global unified ocean observing network.Throughout the development,integration and application of such CVI,the rationality and feasibility of the model have been evaluated.The results confirm that the proposed model can effectively implement heterogeneous system integration,improve development efficiency,make full usage of reusable components,reduce development cost,and enhance overall software system quality.We believe that our new model has great significance to promote the large-scale ocean observing system integration.
基金Project supported by the National Key Research and Development Plan(2021YFA1200201)the Natural Science Foundation of China(51872008)+1 种基金the"111"Project under the DB18015 grantBeijing Outstanding Young Scientists Projects(BJJWZYJH01201910005018)。
文摘The extremely high structural tolerance of ceria to oxygen vacancies(Ov)has made it a desirable catalytic material for the hydrocarbon oxidation to chemicals and pharmaceuticals and the reduction of gaseous pollutants.It is proposed that the formation and diffusion of Ov originate from its outstanding reduction property.However,the formation and diffusion process of Ov over the surface of ceria at the atomic level is still unknown.Herein,the structural and valence evolution of CeO_(2)(111)surfaces in reductive,oxidative and vacuum environments from room temperature up to 700℃was studied with in situ aberration-corrected environmental transmission electron microscopy(ETEM)experiments.Ov is found to form under a high vacuum at elevated temperatures;however,the surface can recover to the initial state through the adsorption of oxygen atoms in an oxygen-contained environment.Furthermore,in hydrogen environment,the step-CeO_(2)(111)surface is not stable at elevated temperatures;thus,the steps tend to be eliminated with increasing temperature.Combined with first-principles density function calculations(DFT),it is proposed that O-terminated surfaces would develop in a hypoxic environment due to the dynamic diffusion of Ov from the outer surface to the subsurface.Furthermore,in a reductive environment,H2 facilitates the formation and diffusion of Ov while Ce-terminated surfaces develope.These results reveal dynamic atomic-scale interplay between the nanoceria surface and gas,thereby providing fundamental insights into the Ov-dependent reaction of nano-CeO_(2) during catalytic processes.
