The development of chemical technologies,which involves a multistage process covering laboratory research,scale‐up to industrial deployment,and necessitates interdisciplinary collaboration,is often accompanied by sub...The development of chemical technologies,which involves a multistage process covering laboratory research,scale‐up to industrial deployment,and necessitates interdisciplinary collaboration,is often accompanied by substantial time and economic costs.To address these challenges,in this work,we report ChemELLM,a domain‐specific large language model(LLM)with 70 billion parameters for chemical engineering.ChemELLM demonstrates state‐of‐the‐art performance across critical tasks ranging from foundational understanding to professional problem‐solving.It outperforms mainstream LLMs(e.g.,O1‐Preview,GPT‐4o,and DeepSeek‐R1)on ChemEBench,the first multidimensional benchmark for chemical engineering,which encompasses 15 dimensions across 101 distinct essential tasks.To support robust model development,we curated ChemEData,a purpose‐built dataset containing 19 billion tokens for pre‐training and 1 billion tokens for fine‐tuning.This work establishes a new paradigm for artificial intelligence‐driven innovation,bridging the gap between laboratory‐scale innovation and industrial‐scale implementation,thus accelerating technological advancement in chemical engineering.ChemELLM is publicly available at https://chemindustry.iflytek.com/chat.展开更多
Vascular stents play an important role in the minimally invasive treatment of vascular diseases,such as vascular stenosis,vascular aneurysm,vascular dissection and vascular atherosclerotic plaque disease.Bare metal st...Vascular stents play an important role in the minimally invasive treatment of vascular diseases,such as vascular stenosis,vascular aneurysm,vascular dissection and vascular atherosclerotic plaque disease.Bare metal stents were initially fabricated;however,the incidence of complications such as thrombosis,inflammation,restenosis,vascular injury,displacement and endoleakage is still high after implantation.To overcome these complications,several strategies for designing functional vascular stents have been carried out.Drug-eluting stents,biodegradable stents and bionic stents were manufactured and investigated.This review aims to comprehensively analyze the vascular diseases suitable for stent implantation treatment,tissue reactions after implantation,the materials and manufacturing techniques used to fabricate vascular stents,the various application scenarios in which they could be used to treat vascular lesions and the development process of vascular stents.Future development trends of vascular stents are expected to prioritize their performance,biocompatibility,and clinical accessibility.The design of vascular stents may be transformed or improved to better fulfill the rehabilitation requirements of vascular disease patients.Finally,various application scenarios may be used to treat vascular or even nonvascular diseases via endovascular access.展开更多
Fischer-Tropsch synthesis(FTS)and hydroformylation are pivotal chemical processes for converting syngas and olefins into valuable hydrocarbons and chemicals.Recent advancements in catalyst design,reaction mechanisms,a...Fischer-Tropsch synthesis(FTS)and hydroformylation are pivotal chemical processes for converting syngas and olefins into valuable hydrocarbons and chemicals.Recent advancements in catalyst design,reaction mechanisms,and process optimization have significantly improved the efficiency,selectivity,and sustainability of these processes.This Account introduces the relevant research activities in the Research Center for Catalysis in Syngas Conversion and Fine Chemicals(DNL0805)of Dalian Institute of Chemical Physics(DICP),Chinese Academy of Sciences.The reactions of interests include FTS,heterogeneous hydroformylation of olefins,alcohol dehydration and oxidation,andα-olefin polymerization,with the emphasis on developing innovative catalysts and processes to address the challenges of traditional processes.Exemplified by the discovery of robust Co-Co_(2)C/AC for FTS and Rh_(1)/POPs-PPh_(3) for heterogeneous hydroformylation of olefins,it demonstrates how lab-scale fundamental understandings on the active sites of catalysts leads to pilot-plant scale-up and finally commercial technologies.Perspectives on the challenges and directions for future developments in these exciting fields are provided.展开更多
China is currently vigorously implementing the“energy conservation and emission reduction”and“dual carbon”strategies.As the most resource-advantaged light metal material in China,Magnesium(Mg)alloy is progressivel...China is currently vigorously implementing the“energy conservation and emission reduction”and“dual carbon”strategies.As the most resource-advantaged light metal material in China,Magnesium(Mg)alloy is progressively expanding its application in automobile,rail transportation,aerospace,medical,and electronic products.Chongqing University,Shanghai Jiaotong University,and Australian National University have conducted extensive research on the preparation,properties,and processes of Mg alloys.In the past 20 years,the proportion of Mg alloy in the automotive industry has gradually expanded,whereas currently the design and development of Mg alloy parts for automobiles has rarely been reported.Thus,the application models and typical parts cases of Mg alloy are summarized mainly from the four systems of the whole vehicle(body system,chassis system,powertrain system,interior,and exterior system).Subsequently,two actual original equipment manufacturers(OEM)cases are used to introduce the development logic of reliable die-cast Mg alloy,including forward design,formability analysis,process design analysis,structural redesign,manufacturing,and testing,aiming to share the methods,processes,and focus of attention of automotive OEMs for developing Mg alloy parts to enhance the confidence and motivation of applying Mg alloy in automotive field.Eventually,the multiple challenges faced by Mg alloy materials are sorted out and how to face these challenges are discussed.National policies and regulations,environmental protection and energy saving,and consumer demand will continue to promote the application of Mg.展开更多
Ambient air quality standards are the core strategic goal of ambient air quality management.Countries worldwide have given importance to research on the development of ambient air quality standards.To understand the h...Ambient air quality standards are the core strategic goal of ambient air quality management.Countries worldwide have given importance to research on the development of ambient air quality standards.To understand the history of the development of China’s ambient air quality standards,this study analyzed the background associated with all previous formulations and revisions of the standards,classification of functional areas,standard grading,pollutants,and evolution of the standard limits over the past 40 years.The results show that since the initial release of the“Ambient Air Quality Standard”by China in 1982,it has been supplemented once,revised twice,and modified twice.The first ambient air quality standard specified the standard limits of six pollutants commonly found in ambient air.With the development of ambient air quality management,the number of pollutants has increased to ten.Since the release of the“Ambient Air Quality Standards”in 2012,the ambient air quality in China has significantly improved.However,the proportion of cities meeting these standards is still low.At present,China is suitably positioned to make the standards associated with 24 hr SO2concentrations more stringent such that it meets the values defined in the World Health Organization(WHO)interim target-2 and the WHO air quality guideline(AQG).We further suggested that the SO2standard should be revised promptly.Simultaneously,regions with a relatively high proportion of cities meeting the standard are encouraged to introduce more stringent interim target limits in due course to manage the local ambient air quality.展开更多
In order to assure quality and control process in the development of the aircraft collaborative design software, a maturity assessment model is proposed. The requirements designing—house of quality is designed to eva...In order to assure quality and control process in the development of the aircraft collaborative design software, a maturity assessment model is proposed. The requirements designing—house of quality is designed to evaluate the maturity degree of the solution, and the evaluation results can help to manage and control the development process. Furthermore, a fuzzy evaluation method based on the minimum deviation is proposed to deal with the fuzzy information. The quantitative evaluation result of the maturity degree can be calculated by optimizing the semantic discount factor aim for the minimum deviation. Finally, this model is illustrated and analyzed by an example study of the aircraft collaborative design software.展开更多
This paper reviewed the trend and development of semi-solid metal technique. The processes and mechanisms for producing slurry of SSM and its industrial applications have been summarized and discussed. Discussions on ...This paper reviewed the trend and development of semi-solid metal technique. The processes and mechanisms for producing slurry of SSM and its industrial applications have been summarized and discussed. Discussions on the basic rheological theory are presented for more applications. Further consideration of the development and application of SSM technique is also proposed.展开更多
Urban Parks play an important role in the urban ecological environment. Based on the profound effect of ecological ideology on urban park design, we stud- ied the evolution course of ecological ideology and the charac...Urban Parks play an important role in the urban ecological environment. Based on the profound effect of ecological ideology on urban park design, we stud- ied the evolution course of ecological ideology and the characteristics of the ecological ideology at different stages in the United States, and emphatically introduced the influence of ecological ideology on the planning and design of New York Central Park, with the aim to summarize the inspiration for the urban park design in China.展开更多
This article presents a multiscale simulation approach starting at the molecular level for the adsorption process development. A grand canonical Monte Carlo method is used for the prediction of adsorption isotherms of...This article presents a multiscale simulation approach starting at the molecular level for the adsorption process development. A grand canonical Monte Carlo method is used for the prediction of adsorption isotherms of methanol on an activated carbon at the molecular level. The adsorption isotherms obtained in the linear region （or adsorption constant） are exploited as a model parameter required for the adsorption process simulation. The adsorption process model described by a set of partial differential equations （PDEs） is solved by using the conservation element and solution element method, which produces a fast and an accurate numerical solution to PDEs. The simulation results obtained from the adsorption constant estimated at the molecular level are in good agreement with the experimental results of the pulse response. The systematical multiscale simulation approach addressed in this study may be useful to accelerate the adsorption process development by reducing the number of experiments.展开更多
An improved and scalable process for substituted 3,8-diazabicyclo[3.2.1]octane was developed.N-Benzyl-2,5-dicarbethoxy-pyrrolidine 2 was reduced to N-benzyl-2.5-dihydroxymethylpyrrolidine 9 and subsequently debenzylat...An improved and scalable process for substituted 3,8-diazabicyclo[3.2.1]octane was developed.N-Benzyl-2,5-dicarbethoxy-pyrrolidine 2 was reduced to N-benzyl-2.5-dihydroxymethylpyrrolidine 9 and subsequently debenzylated to afford N-Boc-2,5- dihydroxymethylpyrrolidine 10.After mesylation of the diol 10 and cyclization with benzylamine,a diversity of scaffold,3,8- diazabicyclo[3.2.1]octane analogue 12 was obtained in a total yield of 42%in five steps.展开更多
Classification,superimposed evolution and sedimentary filling of prototype basins are analyzed based on the Wilson cycle principle of plate theory,by dissecting the evolution history of 483 sedimentary basins around t...Classification,superimposed evolution and sedimentary filling of prototype basins are analyzed based on the Wilson cycle principle of plate theory,by dissecting the evolution history of 483 sedimentary basins around the world since the Pre-cambrian,combined with the three stress environments of tension,compression and shear.It is found that plate tectonic evo-lution controls the superimposed development process and petroleum-bearing conditions of the prototype basins in three as-pects:first,more than 85%of the sedimentary basins in the world are developed from the superimposed development of two or more prototype basins;second,the superposition evolution process of the prototype basin takes Wilson cycle as the cycle and cycles in a fixed trajectory repeatedly.In each stage of a cycle,a specific type of prototype basin can be formed;third,each prototype basin can form a unique tectonic-sedimentary system,which determines its unique source,reservoir,cap conditions etc.For hydrocarbon accumulation,the later superimposed prototype basin can change the oil and gas accumulation conditions of the earlier prototype basin,and may form new petroleum systems.Based on this,by defining the type of a current basin as its prototype basin formed by the latest plate tectonic movement,14 types of prototype basins can be classified in the world,namely,intracontinental growth rift,intr acontinental aborted rift,intercontinental rift,passive continental margin,interior craton,trench,fore-arc rift,ba ck-arc rift,back-arc de pression,back-arc small ocean,peri pheral foreland,back-arc foreland,strike-slip pull-apart,and strike-slip flexural basins.The classification scheme can ensure the uniqueness of the types of in di-vidual sedimentary basin,and make it possible to predict their oil and gas potential scientifically through analogy.展开更多
The heterojunctions between metal and polymer have become the effective ways to produce the lighter,safer and more environmental friendly vehicles for the manufacturing fields of automotive and aerospace.The state-of-...The heterojunctions between metal and polymer have become the effective ways to produce the lighter,safer and more environmental friendly vehicles for the manufacturing fields of automotive and aerospace.The state-of-the-art frictionbased welding techniques are characterized by low peak temperature,severe plastic deformation,energy efficiency and nonpollution,which can simultaneously realize the mechanical and chemical bonding,improving mechanical performances.In this review,the current progress about friction-based welding techniques is summarized,containing technical development,welding tool design,microstructural characteristic,process optimization,surface modification and joining mechanism.The conclusions and prospects are presented,which focus on the practical implications for the manufacturing sectors and recommendations for further research and development.The purpose of this review is to elucidate the benefits of friction-based welding techniques so that these methods may be better exploited and industrialized.展开更多
For dividing-wall distillation columns(DWDCs) separating a heavy-component dominated and wide boiling-point ternary(HCDWBT) mixture, a significant amount of excessive heat exists inevitably in stripping the heavy-comp...For dividing-wall distillation columns(DWDCs) separating a heavy-component dominated and wide boiling-point ternary(HCDWBT) mixture, a significant amount of excessive heat exists inevitably in stripping the heavy-component from the intermediate-component and it can be employed to initiate the development of vapor recompression heat pump(VRHP) assisted DWDC(VRHP-DWDC). Despite dividing wall may locate in the top, middle, and bottom, the optimum VRHP-DWDC is found to involve uniformlytwo VRHP circles. While the first one serves to compress and transform the excessive heat resulted from the separation of the heavy-component from the intermediate-component, the second one to compress and transform the overhead vapor stream of the light-component pre-heated sequentially with the condensate from the first one and the bottom product stream of the heavy-component, both releasing the temperature-elevated latent heat to the pre-fractionator's or common stripping section. The processing of two HCDWBT mixtures of benzene/toluene/o-xylene and n-pentane/n-hexane/n-heptane are selected to assess the derived optimum topological configurations of the VRHP-DWDC and their optimality is confirmed through detailed comparisons with the DWDC and two VRHP-DWDCs involving only one VRHP circle. The proposed strategy helps to tap the full potential of the VRHP-DWDC with considerably alleviated complication in process development.展开更多
Superjunction technology is believed to reach the optimal specific on-resistance and breakdown voltage trade-off.It has become a mainstream technology in silicon high-voltage metal oxide semiconductor field effect tra...Superjunction technology is believed to reach the optimal specific on-resistance and breakdown voltage trade-off.It has become a mainstream technology in silicon high-voltage metal oxide semiconductor field effect transistor devices.Numerous efforts have been conducted to employ the same concept in silicon carbide devices.These works are summarized here.展开更多
Dispersed and peripheral spaces in the urban core are influenced both by the trend towards constant growth as well as social ways of life which are constantly evolving. Following a connotation, these two factors there...Dispersed and peripheral spaces in the urban core are influenced both by the trend towards constant growth as well as social ways of life which are constantly evolving. Following a connotation, these two factors therefore play a crucial role in defining the alternation of urban space--in particular, that of the centers. The main focus of this research article is on the methodology used in the survey and evaluation of ＂centralities＂ as well as their developments over the past four decades （1974-2014） in approaches to urban development that has been developed in Graz.~ The analysis has drawn on the four editions （＂evolution＂） of approaches to urban development as conceived by the city of Graz in order to examine their verbal characteristics in regard to centralities. At the same time, the analysis does not examine presentations of plans which exist in supplementary forms （e.g., explanatory reports and supplemented plans）--it restricts itself solely to the various plans set out in the STEKs.2 The highest degree of accuracy has been applied to the notion of ＂centralis＂ in approaches to urban development. The goal of the research project was to depict the modulation of the notion of ＂centrality＂ in the urban context as a space-forming dimension. Furthermore, it clearly shows the extent to which the notion of the ＂centre＂ （in the widest sense of the word） has become distanced from qualitative, spatial development and at the current time of urban development is experiencing a sort of Renaissance. In the field of ＂urban development＂, architectural references in the context of＂centrality＂ have scarcely been researched. This has led to the opening-up of a complex interdisciplinary research field. In order to make the complex architectural determinants of ＂centrality＂ more accessible to the participating disciplines, approaches to urban development have been explored in the form of a social and spatial analysis.展开更多
China＇s reform and opening-up policy has brought the country a great development opportunity. The high-speed growth of the economy not only led China to a period of industrialization, urbanization, informatization an...China＇s reform and opening-up policy has brought the country a great development opportunity. The high-speed growth of the economy not only led China to a period of industrialization, urbanization, informatization and agricultural modernization, but also exacerbated the situation of the urban–rural dual structure. Based on the review of current studies, we first used the analytic hierarchy process（AHP） method to evaluate the urban–rural development and transformation level by population transformation index, land transformation index, industrial transformation index and social transformation index between 1996 and 2012 around the Bohai Rim Region. Then, based on the results of each index, we used the exploratory spatial data analysis（ESDA） method to investigate the spatial autocorrelation of the change in the urban–rural development transformation index during the 16-year period using Global Moran＇s I index and Local Moran＇s I index. Finally, we investigated the mechanism of change of the urban–rural development transformation index at county level, summarizing five main factors：（1） the radiation from the surrounding big cities,（2） the acceleration of the urbanization process,（3） the upgrading of the industrial structure,（4） the publishing and implementation of a macro development strategy and regional policy, and（5） natural factors such as topology.展开更多
As an important branch of human geography, transportation geography has experienced three periods of evolution: foundation, systematization, and rapid development of the discipline. It has gradually become a relativel...As an important branch of human geography, transportation geography has experienced three periods of evolution: foundation, systematization, and rapid development of the discipline. It has gradually become a relatively mature discipline. During the period 1930– 1980, the development of transportation geography consisted mainly of the publication of theoretical texts. During 1980–2000, it gradually became a systematic discipline. Since the start of the 21 st century, transportation geography has focused mainly on exploring the impacts of transportation on socio-economic development. Currently, studies on transportation geography have led to significant developments in a number of areas, including transportation theory, facility distribution and planning, transportation flows and network analysis, evaluation of transport modes, transportation planning, and simulation and assessment of urban transportation. Such studies have also enriched human geography research, provided a wider geographical overview and elucidated the development mechanism of transportation, as well as helped to understand the impacts of transport development on socio-economic systems. Some findings obtained by geographers have been widely used in transportation geography and related fields, including the four basic laws of transportation generation, the hub–spoke mode of transport organization, the subordinating and guiding functions of transportation on socio-economic development, regional transport dominance measures, accessibility measures, and spatial organization of port systems.展开更多
The function of decision-making in the management of new product development and vehicle design activities is achieved by defining, constructing or evaluating the outcome-oriented, and most effective steps from the su...The function of decision-making in the management of new product development and vehicle design activities is achieved by defining, constructing or evaluating the outcome-oriented, and most effective steps from the sub-steps that form this basic process. The choice of the sub-stages of the basic process or the decision of how to do a job gains importance in terms of the efficiency of the firm’s activities. Therefore, the decision making function is one of the basic elements involved in the formation and development of the basic processes that can comply with the market dynamics of firms. With the new product being developed, the selection, the current editing or the evaluation of the steps that make up the vehicle design activities for the automotive industry companies that exist and compete in the market, bring about significant gains. In the manufacturing industry, the design of the vehicle determines the market spread, while the competitive conditions are driven by the new or improved product decision. In both cases, the automotive industry firms must know the stages of the most appropriate vehicle design in their own right, and the steps of forming new project dynamics must be devised in this direction. In this study, the result oriented activity of the current vehicle design phases used in the automotive industry companies is determined and the order of importance of the stages is listed. For this purpose, under the same conditions of competition (the same market, the same class vehicles develops and manufactures), 4 in the automotive firm administration, a total of 40 employees (4 × 10 process manager) with the vehicle design was evaluated by determining the effectiveness of the use of the stage. At this stage, analytic hierarchy methods applied to each of the phases are explored in practice instead of the use of the significance level automotive company. Study of the vehicle design phase of the automotive industry: structure, process modifications or new project reveals the important values to be configured according to the size.展开更多
The great success of US commercial shale gas exploitation stimulates the shale gas development in China,subsequently,the corresponding supporting policies were issued in the 12th Five-Year Plan.But from the experience...The great success of US commercial shale gas exploitation stimulates the shale gas development in China,subsequently,the corresponding supporting policies were issued in the 12th Five-Year Plan.But from the experience in the US shale gas development,we know that the resulted environmental threats are always an unavoidable issue,but no uniform and standard evaluation system has yet been set up in China.The comprehensive environment refers to the combination of natural ecological environment and external macro-environment.In view of this,we conducted a series of studies on how to set up a comprehensive environmental impact assessment system as well as the related evaluation methodology and models.First,we made an in-depth investigation into shale gas development procedures and any possible environmental impacts,and then compared,screened and modified environmental impact assessment methods for shale gas development.Also,we established an evaluating system and assessment models according to different status of the above two types of environment:the correlation matrix method was employed to assess the impacts on natural ecological environment and the optimization distance method was modified to evaluate the impacts on external macro-environment.Finally,we substitute the two subindexes into the comprehensive environmental impact assessment model and achieved the final numerical result of environmental impact assessment.This model can be used to evaluate if a shale gas project has any impact on environment,compare the impacts before and after a shale gas development project,or the impacts of different projects.展开更多
The purpose of this paper is to explore the development process of a large scale dry port and to analyse what measures and actions are needed in order to support the decision making process and ensure an effective and...The purpose of this paper is to explore the development process of a large scale dry port and to analyse what measures and actions are needed in order to support the decision making process and ensure an effective and efficient dry port that serves the City and the region’s current and future needs. The purpose is explored in the context of Saudi Arabiaand the city ofArriyadh. Key issues identified related to the dry port development are long term planning and crosssector collaboration. The interconnection between the dry port and the overall transport system and aspects, such as location of business, city logistics, road and rail infrastructure, local, regional and national regulations, etc., is strong. This puts challenge on the coordination and alignment of the different organizations, their strategies and objectives. In a complex situation, such as developing a dry port with many stakeholders, it is crucial that the roles of all actors are clearly defined. This is essential for utilizing the dry port as a regional tool for planning. In that regard, it is appropriate that the site location decision is clearly connected with an overall city freight vision and strategy.展开更多
文摘The development of chemical technologies,which involves a multistage process covering laboratory research,scale‐up to industrial deployment,and necessitates interdisciplinary collaboration,is often accompanied by substantial time and economic costs.To address these challenges,in this work,we report ChemELLM,a domain‐specific large language model(LLM)with 70 billion parameters for chemical engineering.ChemELLM demonstrates state‐of‐the‐art performance across critical tasks ranging from foundational understanding to professional problem‐solving.It outperforms mainstream LLMs(e.g.,O1‐Preview,GPT‐4o,and DeepSeek‐R1)on ChemEBench,the first multidimensional benchmark for chemical engineering,which encompasses 15 dimensions across 101 distinct essential tasks.To support robust model development,we curated ChemEData,a purpose‐built dataset containing 19 billion tokens for pre‐training and 1 billion tokens for fine‐tuning.This work establishes a new paradigm for artificial intelligence‐driven innovation,bridging the gap between laboratory‐scale innovation and industrial‐scale implementation,thus accelerating technological advancement in chemical engineering.ChemELLM is publicly available at https://chemindustry.iflytek.com/chat.
基金supported by Natural Science Foundation of China(No.31930067)Natural Science Foundation of Sichuan Province(No.23NSFSC5880)+2 种基金Chengdu Medical Research Project(No.2022004)Natural Science Foundation of Clinical Medical College and Affiliated Hospital of Chengdu University(No.Y202206)Postdoctoral Research and Development Fund of West China Hospital,Sichuan University(No.2023HXBH052).
文摘Vascular stents play an important role in the minimally invasive treatment of vascular diseases,such as vascular stenosis,vascular aneurysm,vascular dissection and vascular atherosclerotic plaque disease.Bare metal stents were initially fabricated;however,the incidence of complications such as thrombosis,inflammation,restenosis,vascular injury,displacement and endoleakage is still high after implantation.To overcome these complications,several strategies for designing functional vascular stents have been carried out.Drug-eluting stents,biodegradable stents and bionic stents were manufactured and investigated.This review aims to comprehensively analyze the vascular diseases suitable for stent implantation treatment,tissue reactions after implantation,the materials and manufacturing techniques used to fabricate vascular stents,the various application scenarios in which they could be used to treat vascular lesions and the development process of vascular stents.Future development trends of vascular stents are expected to prioritize their performance,biocompatibility,and clinical accessibility.The design of vascular stents may be transformed or improved to better fulfill the rehabilitation requirements of vascular disease patients.Finally,various application scenarios may be used to treat vascular or even nonvascular diseases via endovascular access.
文摘Fischer-Tropsch synthesis(FTS)and hydroformylation are pivotal chemical processes for converting syngas and olefins into valuable hydrocarbons and chemicals.Recent advancements in catalyst design,reaction mechanisms,and process optimization have significantly improved the efficiency,selectivity,and sustainability of these processes.This Account introduces the relevant research activities in the Research Center for Catalysis in Syngas Conversion and Fine Chemicals(DNL0805)of Dalian Institute of Chemical Physics(DICP),Chinese Academy of Sciences.The reactions of interests include FTS,heterogeneous hydroformylation of olefins,alcohol dehydration and oxidation,andα-olefin polymerization,with the emphasis on developing innovative catalysts and processes to address the challenges of traditional processes.Exemplified by the discovery of robust Co-Co_(2)C/AC for FTS and Rh_(1)/POPs-PPh_(3) for heterogeneous hydroformylation of olefins,it demonstrates how lab-scale fundamental understandings on the active sites of catalysts leads to pilot-plant scale-up and finally commercial technologies.Perspectives on the challenges and directions for future developments in these exciting fields are provided.
基金supported partly by the Fundamental Research Funds for Central Universities(No.06500203 and No.00007735).
文摘China is currently vigorously implementing the“energy conservation and emission reduction”and“dual carbon”strategies.As the most resource-advantaged light metal material in China,Magnesium(Mg)alloy is progressively expanding its application in automobile,rail transportation,aerospace,medical,and electronic products.Chongqing University,Shanghai Jiaotong University,and Australian National University have conducted extensive research on the preparation,properties,and processes of Mg alloys.In the past 20 years,the proportion of Mg alloy in the automotive industry has gradually expanded,whereas currently the design and development of Mg alloy parts for automobiles has rarely been reported.Thus,the application models and typical parts cases of Mg alloy are summarized mainly from the four systems of the whole vehicle(body system,chassis system,powertrain system,interior,and exterior system).Subsequently,two actual original equipment manufacturers(OEM)cases are used to introduce the development logic of reliable die-cast Mg alloy,including forward design,formability analysis,process design analysis,structural redesign,manufacturing,and testing,aiming to share the methods,processes,and focus of attention of automotive OEMs for developing Mg alloy parts to enhance the confidence and motivation of applying Mg alloy in automotive field.Eventually,the multiple challenges faced by Mg alloy materials are sorted out and how to face these challenges are discussed.National policies and regulations,environmental protection and energy saving,and consumer demand will continue to promote the application of Mg.
基金supported by the National Key Research and Development Program of China(Nos.2019YFC0214800,2020YFC1806303 and 2016YFC0208100)the Fundamental Research Funds for the Central Public-interest Scientific Institution(No.2021YSKY-06)。
文摘Ambient air quality standards are the core strategic goal of ambient air quality management.Countries worldwide have given importance to research on the development of ambient air quality standards.To understand the history of the development of China’s ambient air quality standards,this study analyzed the background associated with all previous formulations and revisions of the standards,classification of functional areas,standard grading,pollutants,and evolution of the standard limits over the past 40 years.The results show that since the initial release of the“Ambient Air Quality Standard”by China in 1982,it has been supplemented once,revised twice,and modified twice.The first ambient air quality standard specified the standard limits of six pollutants commonly found in ambient air.With the development of ambient air quality management,the number of pollutants has increased to ten.Since the release of the“Ambient Air Quality Standards”in 2012,the ambient air quality in China has significantly improved.However,the proportion of cities meeting these standards is still low.At present,China is suitably positioned to make the standards associated with 24 hr SO2concentrations more stringent such that it meets the values defined in the World Health Organization(WHO)interim target-2 and the WHO air quality guideline(AQG).We further suggested that the SO2standard should be revised promptly.Simultaneously,regions with a relatively high proportion of cities meeting the standard are encouraged to introduce more stringent interim target limits in due course to manage the local ambient air quality.
基金supported by the National Natural Science Foundation for Youth of China(61802174)the Natural Science Foundation for Youth of Jiangsu Province(BK20181016)+1 种基金the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(18KJB520019)the Scientific Research Foundation of Nanjing Institute of Technology of China(YKJ201614)
文摘In order to assure quality and control process in the development of the aircraft collaborative design software, a maturity assessment model is proposed. The requirements designing—house of quality is designed to evaluate the maturity degree of the solution, and the evaluation results can help to manage and control the development process. Furthermore, a fuzzy evaluation method based on the minimum deviation is proposed to deal with the fuzzy information. The quantitative evaluation result of the maturity degree can be calculated by optimizing the semantic discount factor aim for the minimum deviation. Finally, this model is illustrated and analyzed by an example study of the aircraft collaborative design software.
基金the National Natural Science foundation of China! (59995440)
文摘This paper reviewed the trend and development of semi-solid metal technique. The processes and mechanisms for producing slurry of SSM and its industrial applications have been summarized and discussed. Discussions on the basic rheological theory are presented for more applications. Further consideration of the development and application of SSM technique is also proposed.
文摘Urban Parks play an important role in the urban ecological environment. Based on the profound effect of ecological ideology on urban park design, we stud- ied the evolution course of ecological ideology and the characteristics of the ecological ideology at different stages in the United States, and emphatically introduced the influence of ecological ideology on the planning and design of New York Central Park, with the aim to summarize the inspiration for the urban park design in China.
基金the Basic Research Program of the Korea Science & Engineering Foundation (KoSEF, No. R01-2006-000-10786-0).
文摘This article presents a multiscale simulation approach starting at the molecular level for the adsorption process development. A grand canonical Monte Carlo method is used for the prediction of adsorption isotherms of methanol on an activated carbon at the molecular level. The adsorption isotherms obtained in the linear region （or adsorption constant） are exploited as a model parameter required for the adsorption process simulation. The adsorption process model described by a set of partial differential equations （PDEs） is solved by using the conservation element and solution element method, which produces a fast and an accurate numerical solution to PDEs. The simulation results obtained from the adsorption constant estimated at the molecular level are in good agreement with the experimental results of the pulse response. The systematical multiscale simulation approach addressed in this study may be useful to accelerate the adsorption process development by reducing the number of experiments.
基金supported by the program of research fund for returning scholars of Ministry of Education of China(No.200812053)
文摘An improved and scalable process for substituted 3,8-diazabicyclo[3.2.1]octane was developed.N-Benzyl-2,5-dicarbethoxy-pyrrolidine 2 was reduced to N-benzyl-2.5-dihydroxymethylpyrrolidine 9 and subsequently debenzylated to afford N-Boc-2,5- dihydroxymethylpyrrolidine 10.After mesylation of the diol 10 and cyclization with benzylamine,a diversity of scaffold,3,8- diazabicyclo[3.2.1]octane analogue 12 was obtained in a total yield of 42%in five steps.
基金Supported by the National Science and Technology Major Project of China(2016ZX0602900)。
文摘Classification,superimposed evolution and sedimentary filling of prototype basins are analyzed based on the Wilson cycle principle of plate theory,by dissecting the evolution history of 483 sedimentary basins around the world since the Pre-cambrian,combined with the three stress environments of tension,compression and shear.It is found that plate tectonic evo-lution controls the superimposed development process and petroleum-bearing conditions of the prototype basins in three as-pects:first,more than 85%of the sedimentary basins in the world are developed from the superimposed development of two or more prototype basins;second,the superposition evolution process of the prototype basin takes Wilson cycle as the cycle and cycles in a fixed trajectory repeatedly.In each stage of a cycle,a specific type of prototype basin can be formed;third,each prototype basin can form a unique tectonic-sedimentary system,which determines its unique source,reservoir,cap conditions etc.For hydrocarbon accumulation,the later superimposed prototype basin can change the oil and gas accumulation conditions of the earlier prototype basin,and may form new petroleum systems.Based on this,by defining the type of a current basin as its prototype basin formed by the latest plate tectonic movement,14 types of prototype basins can be classified in the world,namely,intracontinental growth rift,intr acontinental aborted rift,intercontinental rift,passive continental margin,interior craton,trench,fore-arc rift,ba ck-arc rift,back-arc de pression,back-arc small ocean,peri pheral foreland,back-arc foreland,strike-slip pull-apart,and strike-slip flexural basins.The classification scheme can ensure the uniqueness of the types of in di-vidual sedimentary basin,and make it possible to predict their oil and gas potential scientifically through analogy.
基金supported by the National Natural Science Foundation of China(Nos.52205350 and 52175301)the China Postdoctoral Science Foundation(Nos.2021M690820 and 2021T140151)and the Heilongjiang Postdoctoral Fund(LBH-Z20055).
文摘The heterojunctions between metal and polymer have become the effective ways to produce the lighter,safer and more environmental friendly vehicles for the manufacturing fields of automotive and aerospace.The state-of-the-art frictionbased welding techniques are characterized by low peak temperature,severe plastic deformation,energy efficiency and nonpollution,which can simultaneously realize the mechanical and chemical bonding,improving mechanical performances.In this review,the current progress about friction-based welding techniques is summarized,containing technical development,welding tool design,microstructural characteristic,process optimization,surface modification and joining mechanism.The conclusions and prospects are presented,which focus on the practical implications for the manufacturing sectors and recommendations for further research and development.The purpose of this review is to elucidate the benefits of friction-based welding techniques so that these methods may be better exploited and industrialized.
基金The financial support from National Natural Science Foundation of China (21878011)。
文摘For dividing-wall distillation columns(DWDCs) separating a heavy-component dominated and wide boiling-point ternary(HCDWBT) mixture, a significant amount of excessive heat exists inevitably in stripping the heavy-component from the intermediate-component and it can be employed to initiate the development of vapor recompression heat pump(VRHP) assisted DWDC(VRHP-DWDC). Despite dividing wall may locate in the top, middle, and bottom, the optimum VRHP-DWDC is found to involve uniformlytwo VRHP circles. While the first one serves to compress and transform the excessive heat resulted from the separation of the heavy-component from the intermediate-component, the second one to compress and transform the overhead vapor stream of the light-component pre-heated sequentially with the condensate from the first one and the bottom product stream of the heavy-component, both releasing the temperature-elevated latent heat to the pre-fractionator's or common stripping section. The processing of two HCDWBT mixtures of benzene/toluene/o-xylene and n-pentane/n-hexane/n-heptane are selected to assess the derived optimum topological configurations of the VRHP-DWDC and their optimality is confirmed through detailed comparisons with the DWDC and two VRHP-DWDCs involving only one VRHP circle. The proposed strategy helps to tap the full potential of the VRHP-DWDC with considerably alleviated complication in process development.
基金supported by the National Key Research and Development Program(No.2016YFB0400500)the Key Research and Development Projects in Guangdong Province(No.2019B010144001)。
文摘Superjunction technology is believed to reach the optimal specific on-resistance and breakdown voltage trade-off.It has become a mainstream technology in silicon high-voltage metal oxide semiconductor field effect transistor devices.Numerous efforts have been conducted to employ the same concept in silicon carbide devices.These works are summarized here.
文摘Dispersed and peripheral spaces in the urban core are influenced both by the trend towards constant growth as well as social ways of life which are constantly evolving. Following a connotation, these two factors therefore play a crucial role in defining the alternation of urban space--in particular, that of the centers. The main focus of this research article is on the methodology used in the survey and evaluation of ＂centralities＂ as well as their developments over the past four decades （1974-2014） in approaches to urban development that has been developed in Graz.~ The analysis has drawn on the four editions （＂evolution＂） of approaches to urban development as conceived by the city of Graz in order to examine their verbal characteristics in regard to centralities. At the same time, the analysis does not examine presentations of plans which exist in supplementary forms （e.g., explanatory reports and supplemented plans）--it restricts itself solely to the various plans set out in the STEKs.2 The highest degree of accuracy has been applied to the notion of ＂centralis＂ in approaches to urban development. The goal of the research project was to depict the modulation of the notion of ＂centrality＂ in the urban context as a space-forming dimension. Furthermore, it clearly shows the extent to which the notion of the ＂centre＂ （in the widest sense of the word） has become distanced from qualitative, spatial development and at the current time of urban development is experiencing a sort of Renaissance. In the field of ＂urban development＂, architectural references in the context of＂centrality＂ have scarcely been researched. This has led to the opening-up of a complex interdisciplinary research field. In order to make the complex architectural determinants of ＂centrality＂ more accessible to the participating disciplines, approaches to urban development have been explored in the form of a social and spatial analysis.
基金National Natural Science Foundation of China,No.41130748No.41471143
文摘China＇s reform and opening-up policy has brought the country a great development opportunity. The high-speed growth of the economy not only led China to a period of industrialization, urbanization, informatization and agricultural modernization, but also exacerbated the situation of the urban–rural dual structure. Based on the review of current studies, we first used the analytic hierarchy process（AHP） method to evaluate the urban–rural development and transformation level by population transformation index, land transformation index, industrial transformation index and social transformation index between 1996 and 2012 around the Bohai Rim Region. Then, based on the results of each index, we used the exploratory spatial data analysis（ESDA） method to investigate the spatial autocorrelation of the change in the urban–rural development transformation index during the 16-year period using Global Moran＇s I index and Local Moran＇s I index. Finally, we investigated the mechanism of change of the urban–rural development transformation index at county level, summarizing five main factors：（1） the radiation from the surrounding big cities,（2） the acceleration of the urbanization process,（3） the upgrading of the industrial structure,（4） the publishing and implementation of a macro development strategy and regional policy, and（5） natural factors such as topology.
基金National Natural Science Foundation of China,No.41171107No.41371143
文摘As an important branch of human geography, transportation geography has experienced three periods of evolution: foundation, systematization, and rapid development of the discipline. It has gradually become a relatively mature discipline. During the period 1930– 1980, the development of transportation geography consisted mainly of the publication of theoretical texts. During 1980–2000, it gradually became a systematic discipline. Since the start of the 21 st century, transportation geography has focused mainly on exploring the impacts of transportation on socio-economic development. Currently, studies on transportation geography have led to significant developments in a number of areas, including transportation theory, facility distribution and planning, transportation flows and network analysis, evaluation of transport modes, transportation planning, and simulation and assessment of urban transportation. Such studies have also enriched human geography research, provided a wider geographical overview and elucidated the development mechanism of transportation, as well as helped to understand the impacts of transport development on socio-economic systems. Some findings obtained by geographers have been widely used in transportation geography and related fields, including the four basic laws of transportation generation, the hub–spoke mode of transport organization, the subordinating and guiding functions of transportation on socio-economic development, regional transport dominance measures, accessibility measures, and spatial organization of port systems.
文摘The function of decision-making in the management of new product development and vehicle design activities is achieved by defining, constructing or evaluating the outcome-oriented, and most effective steps from the sub-steps that form this basic process. The choice of the sub-stages of the basic process or the decision of how to do a job gains importance in terms of the efficiency of the firm’s activities. Therefore, the decision making function is one of the basic elements involved in the formation and development of the basic processes that can comply with the market dynamics of firms. With the new product being developed, the selection, the current editing or the evaluation of the steps that make up the vehicle design activities for the automotive industry companies that exist and compete in the market, bring about significant gains. In the manufacturing industry, the design of the vehicle determines the market spread, while the competitive conditions are driven by the new or improved product decision. In both cases, the automotive industry firms must know the stages of the most appropriate vehicle design in their own right, and the steps of forming new project dynamics must be devised in this direction. In this study, the result oriented activity of the current vehicle design phases used in the automotive industry companies is determined and the order of importance of the stages is listed. For this purpose, under the same conditions of competition (the same market, the same class vehicles develops and manufactures), 4 in the automotive firm administration, a total of 40 employees (4 × 10 process manager) with the vehicle design was evaluated by determining the effectiveness of the use of the stage. At this stage, analytic hierarchy methods applied to each of the phases are explored in practice instead of the use of the significance level automotive company. Study of the vehicle design phase of the automotive industry: structure, process modifications or new project reveals the important values to be configured according to the size.
文摘The great success of US commercial shale gas exploitation stimulates the shale gas development in China,subsequently,the corresponding supporting policies were issued in the 12th Five-Year Plan.But from the experience in the US shale gas development,we know that the resulted environmental threats are always an unavoidable issue,but no uniform and standard evaluation system has yet been set up in China.The comprehensive environment refers to the combination of natural ecological environment and external macro-environment.In view of this,we conducted a series of studies on how to set up a comprehensive environmental impact assessment system as well as the related evaluation methodology and models.First,we made an in-depth investigation into shale gas development procedures and any possible environmental impacts,and then compared,screened and modified environmental impact assessment methods for shale gas development.Also,we established an evaluating system and assessment models according to different status of the above two types of environment:the correlation matrix method was employed to assess the impacts on natural ecological environment and the optimization distance method was modified to evaluate the impacts on external macro-environment.Finally,we substitute the two subindexes into the comprehensive environmental impact assessment model and achieved the final numerical result of environmental impact assessment.This model can be used to evaluate if a shale gas project has any impact on environment,compare the impacts before and after a shale gas development project,or the impacts of different projects.
文摘The purpose of this paper is to explore the development process of a large scale dry port and to analyse what measures and actions are needed in order to support the decision making process and ensure an effective and efficient dry port that serves the City and the region’s current and future needs. The purpose is explored in the context of Saudi Arabiaand the city ofArriyadh. Key issues identified related to the dry port development are long term planning and crosssector collaboration. The interconnection between the dry port and the overall transport system and aspects, such as location of business, city logistics, road and rail infrastructure, local, regional and national regulations, etc., is strong. This puts challenge on the coordination and alignment of the different organizations, their strategies and objectives. In a complex situation, such as developing a dry port with many stakeholders, it is crucial that the roles of all actors are clearly defined. This is essential for utilizing the dry port as a regional tool for planning. In that regard, it is appropriate that the site location decision is clearly connected with an overall city freight vision and strategy.
