Cotton bollworm(Helicoverpa armigera) is an important agricultural pest that causes severe yield loss to crops,particularly to cotton.Transgenic Bt crops have been successful in
Since the 18th National Congress of the CPC,Comrade Xi Jinping pools the wisdom of the Communist Party of China(Party for short),focusing on the overall issues,core issues,and key issues under the new situation of uph...Since the 18th National Congress of the CPC,Comrade Xi Jinping pools the wisdom of the Communist Party of China(Party for short),focusing on the overall issues,core issues,and key issues under the new situation of upholding and developing socialism with Chinese characteristics,has made a series of important speeches,proposed a complete set of strategy for national governing,thus。展开更多
Since the 18th National Congress of the Communist Party of China,the CPC Central Committee with Comrade Xi Jinping as the core has scientifically integrated the two overall situations of the country and the internatio...Since the 18th National Congress of the Communist Party of China,the CPC Central Committee with Comrade Xi Jinping as the core has scientifically integrated the two overall situations of the country and the international community as well as the two major issues of development and security,thus forming a series of new concepts,new ideas and new strategies for governing the country.展开更多
Energy is the key to our future.Whether to the production,storage or use of energy,carbon materials could provide a good solution.They are closely related to people’s daily life and regarded as one of the most promis...Energy is the key to our future.Whether to the production,storage or use of energy,carbon materials could provide a good solution.They are closely related to people’s daily life and regarded as one of the most promising candidates for the flexible electrodes in energy storage devices.Recently,a research team from the Qingdao Institute of Bioenergy and Bioprocess Technology,Chinese Academy of Sciences prepared a展开更多
The large-scale application of Zn-air battery requires the development of efficient,low-cost,and stable bifunctional electrocatalysts for the oxygen evolution reaction(OER)and oxygen reduction reaction(ORR).Herein,an ...The large-scale application of Zn-air battery requires the development of efficient,low-cost,and stable bifunctional electrocatalysts for the oxygen evolution reaction(OER)and oxygen reduction reaction(ORR).Herein,an electrocatalyst of a Co/Mo C-nanoparticles embedded N-doped carbon(Co/Mo C@N-C)was prepared via the in-situ encapsulation of Co_(2)(CO)_(8)and Mo(CO)6 in ZIF-8 using ball-milling,followed by pyrolysis under an Ar atmosphere.When used as a bifunctional electrocatalyst,the as-prepared Co/Mo C@N-C showed an ORR half-wave potential of 0.824 V in an alkaline medium and an overpotential of only 290 m V for the OER at 10 m A cm^(-2),which was 70 m V lower than Ru O_(2).The Co/Mo C@N-C was also evaluated as a cathode in a solid-state Zn-air battery and delivered a higher peak discharge power density and better cycling stability(over 1600 min)than Pt/C-Ru O_(2).Most importantly,our work provides a new strategy to prepare bifunctional catalysts and promotes their applications in the energy conversion field.展开更多
Regeneration in the central nervous system(CNS)is limited,and CNS damage often leads to cognitive impairment or permanent functional motor and sensory loss.Impaired regenerative capacity is multifactorial and includes...Regeneration in the central nervous system(CNS)is limited,and CNS damage often leads to cognitive impairment or permanent functional motor and sensory loss.Impaired regenerative capacity is multifactorial and includes inflammation,loss of the bloodbrain barrier,and alteration in the extracellular matrix(ECM).One of the main problems is the formation of a glial scar and the production of inhibitory ECM,such as proteoglycans。展开更多
THE five years since the 18th National Congress of the Communist Party of China (CPC) in 2012 are an extraordinary period in the course of the Party and the state’s development.It is a time when,facing a slew of prof...THE five years since the 18th National Congress of the Communist Party of China (CPC) in 2012 are an extraordinary period in the course of the Party and the state’s development.It is a time when,facing a slew of profound changes at home and abroad including a sluggish world economic recovery,recurrent regional tensions and conflicts,festering展开更多
A rice mill survey covering diverse rice processing companies in terms of their milling output, type of technology and year of establishment was conducted to understand the current situation of the rice milling indust...A rice mill survey covering diverse rice processing companies in terms of their milling output, type of technology and year of establishment was conducted to understand the current situation of the rice milling industry and to identify enablers and barriers to its growth in Nepal. Coarse rice varieties dominate Nepal’s rice processing industry, with a 42% share by total weight, followed by medium rice (34%) and fine varieties (less than 7%). Polished white rice (<em>Arwa</em>) was the dominant rice type in Nepal in the survey, followed by parboiled and steamed rice. The price and profit margins increased from coarse to fine rice varieties and from <em>Arwa</em> to parboiled and steamed rice. The cost of milling also followed a similar trend. The rice milling industry in Nepal largely influences the adoption or non-adoption of any specific type of rice variety by dictating specific brands in the market and this has important implications for rice research and development. The rice processing industry of Nepal was unable to compete with the Indian rice milling industry because of: 1) low profit margins due to the high cost of rice production and procurement, 2) a lack of economies of scale, 3) a lack of milling technologies for long and extra-long and steamed rice in the country and a lack of investment to modernize rice milling technology, and 4) unavailability of paddy throughout the year locally. Millers were willing to upgrade their rice milling technology to include high throughput parboiling, steamed rice as well as long and extra-long grain rice. This will be a strategic decision in counteracting the ever-increasing rice imports in Nepal. We believe that the findings of the study will be vital for formulating an appropriate rice research, development and rice processing strategy for Nepal to achieve food and nutritional security and the Sustainable Development Goals.展开更多
Background: The fragile landscapes of the Himalayan region are highly susceptible to natural hazards, and there is ongoing concern about current and potential climate change impacts. This study provides background inf...Background: The fragile landscapes of the Himalayan region are highly susceptible to natural hazards, and there is ongoing concern about current and potential climate change impacts. This study provides background information on India's Western Himalayas and reviews evidence of warming as well as variability in precipitation and extreme events.Methods: Understanding and anticipating the impacts of climate change on Himalayan forest ecosystems and the services they provide to people are critical. Efforts to develop and implement effective policies and management strategies for climate change mitigation and adaptation requires particular new research initiatives. The various studies initiated and conducted in the region are compiled here.Results: Several new initiatives taken by the Himalayan Forest Research Institute in Shimla are described. This includes new permanent observational field studies, some with mapped trees, in high altitude transitional zones for continuous monitoring of vegetation response. We have also presented new strategies for mitigating potential climate change effects in Himalayan forest ecosystems.Conclusions: Assessment of the ecological and genetic diversity of the Himalayan conifers is required to evaluate potential responses to changing climatic conditions. Conservation strategies for the important temperate medicinal plants need to be developed. The impact of climate change on insects and pathogens in the Himalayas also need to be assessed. Coordinated efforts are necessary to develop effective strategies for adaptation and mitigation.展开更多
The boundaries of manufacturing system have been ex te nded from factory to the international manufacturing network, supply network, va lue network and virtual network in recent decades, driven by intensified competi ...The boundaries of manufacturing system have been ex te nded from factory to the international manufacturing network, supply network, va lue network and virtual network in recent decades, driven by intensified competi tion, fragmented market, globalised collaboration, and advanced technology. However, as the manufacturing system evolves into more and more complicated net work relationship, the fundamental concepts of manufacturing strategy focusing o n a product family and bridging its market, competition and factory system have rarely been adapted to face new challenges from extended system, although the st rategy formation processes are widely discussed from both perspectives in terms of top-down and bottom-up. Coming into the new economy, as manufacturing industry and system have changed their role in both company and society, manufac turing, especially physical fabrications and assembly, has become less critical than ten years ago, and the compatible manufacturing strategy has been also chal lenged by the new rules based on knowledge development and by the new business m odel based on value creation. Manufacturing strategy has to find a position and mechanism contributing itself to the corporate strategy and competitive advanta ge. This paper seeks to answer the question what networked manufacturing systems can imply to the manufacturing strategy, by clarifying some key challenges to the c lassical manufacturing strategy theory, especially from networked manufacturing system and value-based manufacturing strategy perspectives. The paper is based on some preliminary case observations in several multinationa l corporations in aerospace, automotive, engineering and electronics industries. Original objectives are targeted on an evolutionary process of manufacturing system from factory-based system towards globally collaborated inter-firm netw ork, seeking to explain why manufacturing companies evolve into more and more un controllable relationship. The preliminary findings are seriously challenging t he traditional concept of firm and the theory manufacturing strategy developed b y Skinner (1969). Some key findings from the preliminary work include: - value creation is more dependent upon a proposition in the value net than crea tion of competitive edge for existing product line-which ask manufacturing stra tegy should focus more on a higher value - in manufacturing system, leveraging other companies resources seems to be more important than owning these resources - which implies networked virtual enterpr ise is preferred architecture - in inter-firm collaboration, understanding the dynamics and keeping a balance are more and more critical in the spectrum of collaboration from one end of cor porate hierarchy towards another end of free market-which means that a cont ingency picture is more needed than a single supply or virtual network model - from evolution perspective, deeply understandings about internally vertical in tegration, outsourcing, sub-contracting, and manufacturing hollowing-out are n ow more and more important than the single competence knowing how to do them-wh ich means an up-grading towards know-why These new challenges ask new solutions for industry. They imply not only new sy stem architecture of manufacturing system based on an inter-firm relationship b ut new strategy process with a context-based contingency framework. The paper summaries some existing researches and develops a theoretical framework for the new networked manufacturing system. As a preliminary case study, the paper also suggests a further research plan in the future.展开更多
Along with the increase in the consumption of traditional Chinese medicine(TCM), the safety of TCM has dramatically attracted the attention and concern of the public. Here, we review previous studies, which focused ma...Along with the increase in the consumption of traditional Chinese medicine(TCM), the safety of TCM has dramatically attracted the attention and concern of the public. Here, we review previous studies, which focused mainly on the toxicity of toxic TCM and the interpretations for combination, to elaborate on advances and important issues existing in the safety evaluation of TCM, aiming to provide scientific advice for the clinical use. Moreover, we emphasize the importance of a safe evaluation system for TCM based on the material basis for toxicity, which integrates new toxicity testing strategy and is launched under the guidance of TCM theories in future researches.展开更多
Considering the WHO warning about the emergence of a’post-antibiotic’era during the 21st century in which common infections and minor injuries will have a dramatic impact on human death toll,search for new potential...Considering the WHO warning about the emergence of a’post-antibiotic’era during the 21st century in which common infections and minor injuries will have a dramatic impact on human death toll,search for new potential antibacterial drug targets became a necessary need.Targets that are extensively explored concern the modulation展开更多
The 19th National Congress of the Communist Party of China(CPC)has laid out a blueprint for China’s development in the years to come.Xia Yipu,an associate researcher with the Academy of Marxism,Chinese Academy of Soc...The 19th National Congress of the Communist Party of China(CPC)has laid out a blueprint for China’s development in the years to come.Xia Yipu,an associate researcher with the Academy of Marxism,Chinese Academy of Social Sciences,has made a展开更多
IntroductionI have been teaching ESL in Guangzhou for over ten years,and I find the teaching of oral English a ratherdifficult task.A few years ago,I taught the course to first year English majors,using:‘50 EverydayT...IntroductionI have been teaching ESL in Guangzhou for over ten years,and I find the teaching of oral English a ratherdifficult task.A few years ago,I taught the course to first year English majors,using:‘50 EverydayTopics in English’as the coursebook.The topics include‘Greeting and Farewells’,‘Introduction’,‘Calling on somebody’etc.,each consisting of a few dialogues.In each lesson,there is a list of new wordsand a considerable number of pattern drills.When using the book,I conducted the class using the following procedure:1.Students study the new words before class.2.Teacher presents the dialogue and explains the language points.3.Students read aloud the dialogue after the teacher or the tape recording.4.Students practise the pattern drills or do Chinese to English translation for structural practice.5.Students repeat the dialogue in pairs or individually.6.Students act out the dialogue in class.展开更多
Metal oxides with one-dimensional(1-D)nanostructures have shown promise as electrode materials for supercapacitors due to their unique properties,such as high aspect ratio,increased interaction between electrode and e...Metal oxides with one-dimensional(1-D)nanostructures have shown promise as electrode materials for supercapacitors due to their unique properties,such as high aspect ratio,increased interaction between electrode and electrolyte,favourable mechanical strength,and short ion transportation pathways that im-prove the charge-discharge rates of electrons and ions.Electrospinning is an effective technique for cre-ating 1-D metal oxide nanostructures that produce highly porous nanofibrous structures with exceptional specific surface areas,predictable pore size distributions,and tunable interconnected porosity.This paper provides a comprehensive review of the literature on electrospun metal oxide nanostructures for superca-pacitors,including the principles and key parameters of electrospinning,an overview of supercapacitors,the charge storage mechanism of electrospun metal oxides,and recent developments in 1-D electrospun nanostructures,from binary to ternary metal oxides.The review also discusses unresolved issues and future directions in this research field.Overall,this paper offers valuable insights into the latest devel-opments,unresolved issues,and prospects of 1-D nanostructured metal oxides fabricated through elec-trospinning for supercapacitor applications,providing a critical analysis of their potential in this rapidly evolving field.展开更多
With the development of photovoltaic materials, especially the small molecule acceptors(SMAs), organic solar cells(OSCs)have made breakthroughs in power conversion efficiencies(PCEs). However, the stability of high-pe...With the development of photovoltaic materials, especially the small molecule acceptors(SMAs), organic solar cells(OSCs)have made breakthroughs in power conversion efficiencies(PCEs). However, the stability of high-performance OSCs remains a critical challenge for future technological applications. To tackle the inherent instability of SMA materials under the ambient conditions, much effort has been made to improve OSCs stability, including device modification and new materials design. Here we proposed a new electron acceptor design strategy and developed a “quasi-macromolecule”(QM) with an A-π-A structure,where the functionalized π-bridge is used as a linker between two SMAs(A), to improve the long-term stability without deteriorating device efficiencies. Such type of QMs enables excellent synthetic flexibility to modulate their optical/electrochemical properties, crystallization and aggregation behaviors by changing the A and π units. Moreover, QMs possess a unique long conjugated backbone combining high molecular weight over 3.5 k Da with high purity. Compared with the corresponding SMA BTP-4F-OD(Y6-OD), the devices based on newly synthesized A-π-A type acceptors QM1 and QM2 could exhibit better device stability and more promising PCEs of 17.05% and 16.36%, respectively. This kind of “molecular-framework”(A-π-A)structure provides a new design strategy for developing high-efficiency and-stability photovoltaic materials.展开更多
文摘Cotton bollworm(Helicoverpa armigera) is an important agricultural pest that causes severe yield loss to crops,particularly to cotton.Transgenic Bt crops have been successful in
文摘Since the 18th National Congress of the CPC,Comrade Xi Jinping pools the wisdom of the Communist Party of China(Party for short),focusing on the overall issues,core issues,and key issues under the new situation of upholding and developing socialism with Chinese characteristics,has made a series of important speeches,proposed a complete set of strategy for national governing,thus。
文摘Since the 18th National Congress of the Communist Party of China,the CPC Central Committee with Comrade Xi Jinping as the core has scientifically integrated the two overall situations of the country and the international community as well as the two major issues of development and security,thus forming a series of new concepts,new ideas and new strategies for governing the country.
基金supported by the Chinese Academy of Sciencesthe Natural Science Foundation of Shandong Provincethe National Natural Science Foundation of China
文摘Energy is the key to our future.Whether to the production,storage or use of energy,carbon materials could provide a good solution.They are closely related to people’s daily life and regarded as one of the most promising candidates for the flexible electrodes in energy storage devices.Recently,a research team from the Qingdao Institute of Bioenergy and Bioprocess Technology,Chinese Academy of Sciences prepared a
基金the Program of Introducing Talents of Discipline to Universities(B18030)the National Natural Science Foundation of China(21421001 and 21531005)+2 种基金the Natural Science Foundation of Tianjin City(19JCZDJC37200)the National Postdoctoral Program for Innovative Talents(BX20190157)the China Postdoctoral Science Foundation(2019 M660979)。
文摘The large-scale application of Zn-air battery requires the development of efficient,low-cost,and stable bifunctional electrocatalysts for the oxygen evolution reaction(OER)and oxygen reduction reaction(ORR).Herein,an electrocatalyst of a Co/Mo C-nanoparticles embedded N-doped carbon(Co/Mo C@N-C)was prepared via the in-situ encapsulation of Co_(2)(CO)_(8)and Mo(CO)6 in ZIF-8 using ball-milling,followed by pyrolysis under an Ar atmosphere.When used as a bifunctional electrocatalyst,the as-prepared Co/Mo C@N-C showed an ORR half-wave potential of 0.824 V in an alkaline medium and an overpotential of only 290 m V for the OER at 10 m A cm^(-2),which was 70 m V lower than Ru O_(2).The Co/Mo C@N-C was also evaluated as a cathode in a solid-state Zn-air battery and delivered a higher peak discharge power density and better cycling stability(over 1600 min)than Pt/C-Ru O_(2).Most importantly,our work provides a new strategy to prepare bifunctional catalysts and promotes their applications in the energy conversion field.
文摘Regeneration in the central nervous system(CNS)is limited,and CNS damage often leads to cognitive impairment or permanent functional motor and sensory loss.Impaired regenerative capacity is multifactorial and includes inflammation,loss of the bloodbrain barrier,and alteration in the extracellular matrix(ECM).One of the main problems is the formation of a glial scar and the production of inhibitory ECM,such as proteoglycans。
文摘THE five years since the 18th National Congress of the Communist Party of China (CPC) in 2012 are an extraordinary period in the course of the Party and the state’s development.It is a time when,facing a slew of profound changes at home and abroad including a sluggish world economic recovery,recurrent regional tensions and conflicts,festering
文摘A rice mill survey covering diverse rice processing companies in terms of their milling output, type of technology and year of establishment was conducted to understand the current situation of the rice milling industry and to identify enablers and barriers to its growth in Nepal. Coarse rice varieties dominate Nepal’s rice processing industry, with a 42% share by total weight, followed by medium rice (34%) and fine varieties (less than 7%). Polished white rice (<em>Arwa</em>) was the dominant rice type in Nepal in the survey, followed by parboiled and steamed rice. The price and profit margins increased from coarse to fine rice varieties and from <em>Arwa</em> to parboiled and steamed rice. The cost of milling also followed a similar trend. The rice milling industry in Nepal largely influences the adoption or non-adoption of any specific type of rice variety by dictating specific brands in the market and this has important implications for rice research and development. The rice processing industry of Nepal was unable to compete with the Indian rice milling industry because of: 1) low profit margins due to the high cost of rice production and procurement, 2) a lack of economies of scale, 3) a lack of milling technologies for long and extra-long and steamed rice in the country and a lack of investment to modernize rice milling technology, and 4) unavailability of paddy throughout the year locally. Millers were willing to upgrade their rice milling technology to include high throughput parboiling, steamed rice as well as long and extra-long grain rice. This will be a strategic decision in counteracting the ever-increasing rice imports in Nepal. We believe that the findings of the study will be vital for formulating an appropriate rice research, development and rice processing strategy for Nepal to achieve food and nutritional security and the Sustainable Development Goals.
文摘Background: The fragile landscapes of the Himalayan region are highly susceptible to natural hazards, and there is ongoing concern about current and potential climate change impacts. This study provides background information on India's Western Himalayas and reviews evidence of warming as well as variability in precipitation and extreme events.Methods: Understanding and anticipating the impacts of climate change on Himalayan forest ecosystems and the services they provide to people are critical. Efforts to develop and implement effective policies and management strategies for climate change mitigation and adaptation requires particular new research initiatives. The various studies initiated and conducted in the region are compiled here.Results: Several new initiatives taken by the Himalayan Forest Research Institute in Shimla are described. This includes new permanent observational field studies, some with mapped trees, in high altitude transitional zones for continuous monitoring of vegetation response. We have also presented new strategies for mitigating potential climate change effects in Himalayan forest ecosystems.Conclusions: Assessment of the ecological and genetic diversity of the Himalayan conifers is required to evaluate potential responses to changing climatic conditions. Conservation strategies for the important temperate medicinal plants need to be developed. The impact of climate change on insects and pathogens in the Himalayas also need to be assessed. Coordinated efforts are necessary to develop effective strategies for adaptation and mitigation.
文摘The boundaries of manufacturing system have been ex te nded from factory to the international manufacturing network, supply network, va lue network and virtual network in recent decades, driven by intensified competi tion, fragmented market, globalised collaboration, and advanced technology. However, as the manufacturing system evolves into more and more complicated net work relationship, the fundamental concepts of manufacturing strategy focusing o n a product family and bridging its market, competition and factory system have rarely been adapted to face new challenges from extended system, although the st rategy formation processes are widely discussed from both perspectives in terms of top-down and bottom-up. Coming into the new economy, as manufacturing industry and system have changed their role in both company and society, manufac turing, especially physical fabrications and assembly, has become less critical than ten years ago, and the compatible manufacturing strategy has been also chal lenged by the new rules based on knowledge development and by the new business m odel based on value creation. Manufacturing strategy has to find a position and mechanism contributing itself to the corporate strategy and competitive advanta ge. This paper seeks to answer the question what networked manufacturing systems can imply to the manufacturing strategy, by clarifying some key challenges to the c lassical manufacturing strategy theory, especially from networked manufacturing system and value-based manufacturing strategy perspectives. The paper is based on some preliminary case observations in several multinationa l corporations in aerospace, automotive, engineering and electronics industries. Original objectives are targeted on an evolutionary process of manufacturing system from factory-based system towards globally collaborated inter-firm netw ork, seeking to explain why manufacturing companies evolve into more and more un controllable relationship. The preliminary findings are seriously challenging t he traditional concept of firm and the theory manufacturing strategy developed b y Skinner (1969). Some key findings from the preliminary work include: - value creation is more dependent upon a proposition in the value net than crea tion of competitive edge for existing product line-which ask manufacturing stra tegy should focus more on a higher value - in manufacturing system, leveraging other companies resources seems to be more important than owning these resources - which implies networked virtual enterpr ise is preferred architecture - in inter-firm collaboration, understanding the dynamics and keeping a balance are more and more critical in the spectrum of collaboration from one end of cor porate hierarchy towards another end of free market-which means that a cont ingency picture is more needed than a single supply or virtual network model - from evolution perspective, deeply understandings about internally vertical in tegration, outsourcing, sub-contracting, and manufacturing hollowing-out are n ow more and more important than the single competence knowing how to do them-wh ich means an up-grading towards know-why These new challenges ask new solutions for industry. They imply not only new sy stem architecture of manufacturing system based on an inter-firm relationship b ut new strategy process with a context-based contingency framework. The paper summaries some existing researches and develops a theoretical framework for the new networked manufacturing system. As a preliminary case study, the paper also suggests a further research plan in the future.
基金financially supported by the National Natural Science Foundation of China(No.81630102 and No.81803833)
文摘Along with the increase in the consumption of traditional Chinese medicine(TCM), the safety of TCM has dramatically attracted the attention and concern of the public. Here, we review previous studies, which focused mainly on the toxicity of toxic TCM and the interpretations for combination, to elaborate on advances and important issues existing in the safety evaluation of TCM, aiming to provide scientific advice for the clinical use. Moreover, we emphasize the importance of a safe evaluation system for TCM based on the material basis for toxicity, which integrates new toxicity testing strategy and is launched under the guidance of TCM theories in future researches.
文摘Considering the WHO warning about the emergence of a’post-antibiotic’era during the 21st century in which common infections and minor injuries will have a dramatic impact on human death toll,search for new potential antibacterial drug targets became a necessary need.Targets that are extensively explored concern the modulation
文摘The 19th National Congress of the Communist Party of China(CPC)has laid out a blueprint for China’s development in the years to come.Xia Yipu,an associate researcher with the Academy of Marxism,Chinese Academy of Social Sciences,has made a
文摘IntroductionI have been teaching ESL in Guangzhou for over ten years,and I find the teaching of oral English a ratherdifficult task.A few years ago,I taught the course to first year English majors,using:‘50 EverydayTopics in English’as the coursebook.The topics include‘Greeting and Farewells’,‘Introduction’,‘Calling on somebody’etc.,each consisting of a few dialogues.In each lesson,there is a list of new wordsand a considerable number of pattern drills.When using the book,I conducted the class using the following procedure:1.Students study the new words before class.2.Teacher presents the dialogue and explains the language points.3.Students read aloud the dialogue after the teacher or the tape recording.4.Students practise the pattern drills or do Chinese to English translation for structural practice.5.Students repeat the dialogue in pairs or individually.6.Students act out the dialogue in class.
基金This work was financially supported by the National Research Foundation of Korea,South Korea(No.NRF 2020R1A2C1015206).
文摘Metal oxides with one-dimensional(1-D)nanostructures have shown promise as electrode materials for supercapacitors due to their unique properties,such as high aspect ratio,increased interaction between electrode and electrolyte,favourable mechanical strength,and short ion transportation pathways that im-prove the charge-discharge rates of electrons and ions.Electrospinning is an effective technique for cre-ating 1-D metal oxide nanostructures that produce highly porous nanofibrous structures with exceptional specific surface areas,predictable pore size distributions,and tunable interconnected porosity.This paper provides a comprehensive review of the literature on electrospun metal oxide nanostructures for superca-pacitors,including the principles and key parameters of electrospinning,an overview of supercapacitors,the charge storage mechanism of electrospun metal oxides,and recent developments in 1-D electrospun nanostructures,from binary to ternary metal oxides.The review also discusses unresolved issues and future directions in this research field.Overall,this paper offers valuable insights into the latest devel-opments,unresolved issues,and prospects of 1-D nanostructured metal oxides fabricated through elec-trospinning for supercapacitor applications,providing a critical analysis of their potential in this rapidly evolving field.
基金supported by the National Natural Science Foundation of China (52125306, 21875286, 22005347)the Natural Science Foundation of Hunan Province (2021JJ20068)the National Key Research and Development Program of China (2017YFA0206600)。
文摘With the development of photovoltaic materials, especially the small molecule acceptors(SMAs), organic solar cells(OSCs)have made breakthroughs in power conversion efficiencies(PCEs). However, the stability of high-performance OSCs remains a critical challenge for future technological applications. To tackle the inherent instability of SMA materials under the ambient conditions, much effort has been made to improve OSCs stability, including device modification and new materials design. Here we proposed a new electron acceptor design strategy and developed a “quasi-macromolecule”(QM) with an A-π-A structure,where the functionalized π-bridge is used as a linker between two SMAs(A), to improve the long-term stability without deteriorating device efficiencies. Such type of QMs enables excellent synthetic flexibility to modulate their optical/electrochemical properties, crystallization and aggregation behaviors by changing the A and π units. Moreover, QMs possess a unique long conjugated backbone combining high molecular weight over 3.5 k Da with high purity. Compared with the corresponding SMA BTP-4F-OD(Y6-OD), the devices based on newly synthesized A-π-A type acceptors QM1 and QM2 could exhibit better device stability and more promising PCEs of 17.05% and 16.36%, respectively. This kind of “molecular-framework”(A-π-A)structure provides a new design strategy for developing high-efficiency and-stability photovoltaic materials.
