Anion exchange membrane(AEM),as a kind of key membrane materials,has shown great application potential in many electrochemical fields,and remarkable progress has been made in related research in recent years.In this p...Anion exchange membrane(AEM),as a kind of key membrane materials,has shown great application potential in many electrochemical fields,and remarkable progress has been made in related research in recent years.In this paper,the research status of AEM is reviewed,including its material design,preparation method,performance optimization and application in the fields of hydrogen production by electrolytic water,fuel cell and water treatment.In terms of material design,new polymer skeleton structures are emerging to regulate the stability of ion conduction channels and membranes by introducing specific functional groups or changing the molecular chain structure.The preparation methods have been gradually expanded from the traditional solution casting method to more advanced technologies,such as interfacial polymerization and electrostatic spinning,which effectively improve the microstructure and property uniformity of the film.Performance optimization focuses on improving ion conductivity,reducing membrane swelling rate and enhancing chemical stability,and a variety of modification strategies are developed and applied.Despite the achievements made so far,there are still some challenges,such as the lack of long-term stability in highly alkaline environments.Future research needs to further explore new material systems and preparation processes in order to promote the wide application and sustainable development of AEM technology in energy,environmental protection and other fields.展开更多
The convergence of materials science and biotechnology has catalyzed the development of innovative platforms,including nanotechnology,smart sensors,and supramolecular materials,significantly advancing the progress in ...The convergence of materials science and biotechnology has catalyzed the development of innovative platforms,including nanotechnology,smart sensors,and supramolecular materials,significantly advancing the progress in the field of life sciences[1−7].Among them,supramolecular materials have garnered increasing attention in life sciences owing to their distinctive self-assembly capabilities and intelligent responsiveness[8−12].展开更多
Memory enables organisms to encode,store,and retrieve information essential for interacting with and adapting to a dynamic environment.As an internal representation of the external world,memory serves as a crucial bri...Memory enables organisms to encode,store,and retrieve information essential for interacting with and adapting to a dynamic environment.As an internal representation of the external world,memory serves as a crucial bridge between past experiences and future behaviors.However,the brain continuously forms new memories,raising the question of how new memories are integrated without disrupting previously formed ones.展开更多
The development of low-energy consumption and environmentally friendly electrodeposition of metal/alloy films or coatings is presently one of the primary topics for the research community.For this purpose,deep eutecti...The development of low-energy consumption and environmentally friendly electrodeposition of metal/alloy films or coatings is presently one of the primary topics for the research community.For this purpose,deep eutectic solvents(DESs)are valued as electrolytes for their advantages of low operating temperature and wide electrochemical windows.At present,there is large amount of literature on this emerging field,but there are no specialized reviews of these studies.Here,after a brief introduction of DESs’concept and history,we comprehensively reviewed the lastest progress on the metal/alloy electrodeposition in DESs.Additionally,we discussed the key influence factors of the electrodeposition process and analyzed the corresponding mechanisms.Based on these,we emphasized the importance of the establishment of predictive models for dealing with the challenges in large-scale applications.展开更多
This paper reviews briefly advances in recent research on monsoon by Chinese scholars, including primarily： （1） the establishment of various monsoon indices. In particular, the standardized dynamic seasonal variabi...This paper reviews briefly advances in recent research on monsoon by Chinese scholars, including primarily： （1） the establishment of various monsoon indices. In particular, the standardized dynamic seasonal variability index of the monsoon can delimit the geographical distribution of global monsoon systems and determine quantitatively the date of abrupt change in circulation. （2） The provision of three driving forces for the generation of monsoon. （3） The revelation of the heating-pump action of the Tibetan Plateau, which strengthens southerlies in the southern and southeastern periphery of the Plateau and results in a strong rainfall center from the northern Bay of Bengal （BOB） to the Plateau itself. （4） Clarification of the initial onset of the Asian Summer Monsoon （ASM） in the BOB east of 90°E, Indochina Peninsula （ICP） and the South China Sea, of which the rapid northward progression of tropical convection in the Sumatra and the rapid westward movement of the South Asia High to the Indochina Peninsula are the earliest signs. （5） The provision of an integrated mechanism for the onset of the East Asian Summer Monsoon （EASM）, which emphasizes the integrated impact of sensible heat over Indian Peninsula, the warm advection of the Tibetan Plateau and the sensible heat and latent heat over the Indochina Peninsula on the one hand, and the seasonal phase-lock effect of the northward propagation of low frequency oscillation on the other. （6） The revelation of the ＂planetary-scale moisture transport large-value band＂ from the Southern Hemisphere through to the Asian monsoon region and into the North Pacific, which is converged by several large-scale moisture transport belts in the Asian-Australian monsoon regions and whose variation influences directly the temporal and spatial distribution of summer rainfall in China. （7） Presenting the features of the seasonal advance of the EASM, the propagation of intraseasonal oscillation, and their relationship with rainfall in China; indicating that the intraseasonal oscillation of the EASM propagates in the form of a wave-train along the coast and behaves as monsoon surge propagating northward. （8） Describing the interannual and interdecadal variation of Asian monsoon, revealing the factors affecting it, and possible mechanisms of the variation of Asian monsoon. An elementary outlook on the existing problems and future direction of monsoon research is also provided.展开更多
Interest in the possibility of storing and transporting natural gas in the form of clathrate hydrates has been increasing in recent years, particularly in some gas-importing and exporting countries.The technologies ne...Interest in the possibility of storing and transporting natural gas in the form of clathrate hydrates has been increasing in recent years, particularly in some gas-importing and exporting countries.The technologies necessary for realizing this possibility may be classified into those relevant to the four serial processes (a) the formation of a hydrate, (b) the processing (dewatering, pelletizing, etc. ) of the formed hydrate, (c) the storage and transportation of the processed hydrate, and (d) the regasification (dissociation) of the hydrate. The technological development of any of these processes is still at an early stage. For hydrate formation, for example, various rival operations have been proposed. However,many of them have never been subjected to actual tests for practical use. More efforts are required for examining the different hydrate-formation technologies and for rating them by comparison. The general design of the processing of the formed hydrate inevitably depends on both the hydrate-formation process and the storage/transportation process, hence it has a wide variability. The major uncertainty in the storage-process design lies in the as-yet unclarified utility of the "self-preservation" effect of the naturalgas hydrates. The process design as well as the relevant cost evaluation should strongly depend on whether the hydrates are well preserved at atmospheric pressure in large-scale storage facilities. The regasification process has been studied less extensively than the former processes. The state of the art of the technological development in each of the serial processes is reviewed, placing emphasis on the hydrate formation process.展开更多
Based on historical documents, modern survey and statistics, as well as the result of predecessor studies, the trend and main process of forest dynamics are recognized. The forest area and forest coverage rates for ea...Based on historical documents, modern survey and statistics, as well as the result of predecessor studies, the trend and main process of forest dynamics are recognized. The forest area and forest coverage rates for each province of China from 1700 to 1949 are estimated backward by every 50 years. Linking the result with modern National Forest Inventory data, the spatial-temporal dynamics of Chinese forest in recent 300 years （AD 1700-1998） is quantitatively analyzed. The study shows that in recent 300 years, the forest area in current territory of China has declined by 0.95×10^8 hm^2 （or 9.2% of the coverage rate） in total, with a trend of decrease and recovery. Before the 1960s, there was a trend of accelerated descending. The forest area was reduced by 1.66×10^8 hm^2 （or 17% of the coverage rate） in 260 years. While after the 1960s, there has been a rapid increase. The forest area increased by 0.7×10^8 hm^2 （or 8% of the coverage rate） in 40 years. The study also shows that there is a significant spatial difference in the dynamics of forest. The amplitudes of increasing and decreasing in western China are both smaller than the ones in eastern China. During the rapid declining period from 1700 to 1949, the most serious decrease appeared in the Northeast, the Southwest and the Southeast, where the coverage rate in most provinces dropped over 20%. In Heilongjiang Province, the coverage rate dropped by 50%. In Jilin Province, it dropped by 36%. In Sichuan Province and Chongqing Municipality, it dropped by 42%. In Yunnan Province, it dropped by 35%. During the recovery period 1949-1998, the western provinces, municipality and autonomous regions, including Ningxia, Gansu, Inner Mongolia, Sichuan-Chongqing, Yunnan, Tibet, Xinjiang and Qinghai, etc, the increase rates are all below 5%, while the eastern provinces, municipality and autonomous regions （except Heilongjiang, Hubei, Jiangsu-Shanghai） have achieved an increase over 5%, among which the Guangdong-Hainan, Guangxi, Anhui, Beijing-Tianjin-Hebei, Shandong, Henan, Zhejiang, and Fujian have an increase over 10%.展开更多
The growing demand for energy storage has inspired researchers’exploration of advanced batteries.Aqueous zinc ion batteries(ZIBs)are promising secondary chemical battery system that can be selected and pursued.Rechar...The growing demand for energy storage has inspired researchers’exploration of advanced batteries.Aqueous zinc ion batteries(ZIBs)are promising secondary chemical battery system that can be selected and pursued.Rechargeable ZIBs possess merits of high security,low cost,environmental friendliness,and competitive performance,and they are received a lot of attention.However,the development of suitable zinc ion intercalation-type cathode materials is still a big challenge,resulting in failing to meet the commercial needs of ZIBs.Both vanadium-based and manganese-based compounds are representative of the most advanced and most widely used rechargeable ZIBs electrodes.The valence state of vanadium is+2~+5,which can realize multi-electron transfer in the redox reaction and has a high specific capacity.Most of the manganese-based compounds have tunnel structure or three-dimensional space frame,with enough space to accommodate zinc ions.In order to understand the energy storage mechanism and electrochemical performance of these two materials,a specialized review focusing on state-of-the-art developments is needed.This review offers access for researchers to keep abreast of the research progress of cathode materials for ZIBs.The latest advanced researches in vanadium-based and manganese-based cathode materials applied in aqueous ZIBs are highlighted.This article will provide useful guidance for future studies on cathode materials and aqueous ZIBs.展开更多
As a promising signaling transduction approach, fluorescence polarization(FP)/fluorescence anisotropy(FA), provides a powerful quantitative tool for the rotational motion of fluorescently labeled molecules in chemical...As a promising signaling transduction approach, fluorescence polarization(FP)/fluorescence anisotropy(FA), provides a powerful quantitative tool for the rotational motion of fluorescently labeled molecules in chemical or biological homogeneous systems. Unlike fluorescence intensity, FP/FA is almost independent the concentration or quantum of fluorophores, but they are highly dependent on the size or molecular weight of the molecules or materials attached to fluorophores. Recently, significant progress in FP/FA was made, due to the introduction of some nanomaterials as FP/FA enhancers. The detection sensitivity is thus greatly improved by using nanomaterials as FP/FA enhancers, and nanomaterial-based FP/FA is currently used successfully in immunoassay, and analysis of protein, nucleic acid, small molecule and metal ion.Nanomaterial-based FP/FA provides a new kind of strategy to design fluorescent sensors and establishes innovative analytical methods. In this review, we summarize the scientific publications in the field of FP/FA sensor in recent five years, and first introduce the recent progress of FP/FA sensor based on nanomaterial. Subsequently, the various analytical applications of FP/FA based on nanomaterial are discussed. Finally, we provide perspectives on the current challenges and future prospects in this promising field.展开更多
The technique of endoscopic submucosal dissection(ESD)is now a well-known endoscopic therapy for early gastric cancer.ESD was introduced to resect large specimens of early gastric cancer in a single piece.ESD can prov...The technique of endoscopic submucosal dissection(ESD)is now a well-known endoscopic therapy for early gastric cancer.ESD was introduced to resect large specimens of early gastric cancer in a single piece.ESD can provide precision of histologic diagnosis and can also reduce the recurrence rate.However,the drawback of ESD is its technical difficulty,and,consequently,it is associated with a high rate of complications,the need for advanced endoscopic techniques,and a lengthy procedure time.Various advances in the devices and techniques used for ESD have contributed to overcoming these drawbacks.展开更多
This paper summarizes main progresses made in tropical cyclone research field in China in the past few years after the 8th five year program of China. New achievements have been made on tropical cyclone (hereafter ref...This paper summarizes main progresses made in tropical cyclone research field in China in the past few years after the 8th five year program of China. New achievements have been made on tropical cyclone (hereafter referred as TC) structure, numerical prediction, evaluation of operational numerical model, TC–caused heavy rain, TC climate features and disasters, etc.展开更多
Recent progress in the production and technology of ductile cast iron castings in China is reviewed. The manufacture and process control of as-cast ductile iron are discussed. The microstructure, properties and applic...Recent progress in the production and technology of ductile cast iron castings in China is reviewed. The manufacture and process control of as-cast ductile iron are discussed. The microstructure, properties and application of partial austenitization normalizing ductile iron and austempered ductile iron (ADI) are briefly depicted. The new development of ductile iron production techniques, such as cored-wire injection (wire-feeding nodularization) process, tundish cover ladle nodularizing process, horizontal continuous casting, and EPC process (lost foam) for ductile iron castings, etc., are summarized.展开更多
The CC1 core, with a length of 216 cm, was drilled in the west part of the Chen Co (Lake) in southern Tibet Plateau. The210Pb and137Cs measurement indicated that it was a consecutive sedimentary sequence since ca. 140...The CC1 core, with a length of 216 cm, was drilled in the west part of the Chen Co (Lake) in southern Tibet Plateau. The210Pb and137Cs measurement indicated that it was a consecutive sedimentary sequence since ca. 1400 years. The ostracoda and their assemblages under the level of 1 cm samples’ cutting interval were finished for this core to reveal the past environmental changes in the lake area. A total of 15 species of ostracods belonging to 7 genera in the core sediments had been identified. According to the ostracod distributions, abundances and preservations in the core, seven ostracod assemblages had been distinguished. The ostracod assemblages and their ecological features, together with the sediments dating decision were used to infer the past ca. 1400 years environmental changes of the Chen Co environmental evolutions in three stages, which had responded to the Medieval Ages Warm-period (MAW), the Little Ice Age (LIA) and modern warm period. The results show that the changes of the Chen Co environment had been mainly influenced by the climatic variations. The trend of the lake level fluctuations had been accorded with that of climatic variation during the past 1400 years.展开更多
1.Introduction Compared with the United States,whose annual number of tornadoes can exceed 1000,the average number of tornadoes per year in China over the past half a century is estimated to be fewer than 100（Fan and...1.Introduction Compared with the United States,whose annual number of tornadoes can exceed 1000,the average number of tornadoes per year in China over the past half a century is estimated to be fewer than 100（Fan and Yu,2015）,even though both countries are located in a similar latitudinal zone of the Northern Hemisphere.展开更多
Atmospheric chemistry research has been growing rapidly in China in the last 25 years since the concept of the“air pollution complex”was first proposed by Professor Xiaoyan TANG in 1997.For papers published in 2021 ...Atmospheric chemistry research has been growing rapidly in China in the last 25 years since the concept of the“air pollution complex”was first proposed by Professor Xiaoyan TANG in 1997.For papers published in 2021 on air pollution(only papers included in the Web of Science Core Collection database were considered),more than 24000 papers were authored or co-authored by scientists working in China.In this paper,we review a limited number of representative and significant studies on atmospheric chemistry in China in the last few years,including studies on(1)sources and emission inventories,(2)atmospheric chemical processes,(3)interactions of air pollution with meteorology,weather and climate,(4)interactions between the biosphere and atmosphere,and(5)data assimilation.The intention was not to provide a complete review of all progress made in the last few years,but rather to serve as a starting point for learning more about atmospheric chemistry research in China.The advances reviewed in this paper have enabled a theoretical framework for the air pollution complex to be established,provided robust scientific support to highly successful air pollution control policies in China,and created great opportunities in education,training,and career development for many graduate students and young scientists.This paper further highlights that developing and low-income countries that are heavily affected by air pollution can benefit from these research advances,whilst at the same time acknowledging that many challenges and opportunities still remain in atmospheric chemistry research in China,to hopefully be addressed over the next few decades.展开更多
Air pollution has environmental issue owing become a serious to its diverse harmful effects on the physical and biological environment. According to the Environmental Protection Agency （EPA） and the World Health Org...Air pollution has environmental issue owing become a serious to its diverse harmful effects on the physical and biological environment. According to the Environmental Protection Agency （EPA） and the World Health Organization （WHO）, air pollution affects millions of people worldwide. Hundreds of thousands of deaths each year and a range of diseases, particularly among vulnerable groups （i.e., children, the elderly, and people with special medical conditions）, are attributed to air pollution. These effects are not always caused by single pollutant in the air; rather, they are considered consequences of the multi-pollutants to which people are simultaneously exposed.展开更多
Biomedical applications of nanomaterials are exponentially increasing every year due to analogy to various cell receptors, ligands, structural proteins, and genetic materials(that is, DNA). In bone tissue, nanoscale m...Biomedical applications of nanomaterials are exponentially increasing every year due to analogy to various cell receptors, ligands, structural proteins, and genetic materials(that is, DNA). In bone tissue, nanoscale materials can provide scaffold for excellent tissue repair via mechanical stimulation, releasing of various loaded drugs and mediators, 3D scaffold for cell growth and differentiation of bone marrow stem cells to osteocytes. This review will therefore highlight recent advancements on tissue and nanoscale materials interaction.展开更多
1.Introduction Surface integrity has great significance for the quality and performance of machined components,and has therefore been increasingly recognized by industry.In particular,within certain industries that re...1.Introduction Surface integrity has great significance for the quality and performance of machined components,and has therefore been increasingly recognized by industry.In particular,within certain industries that require high reliability,such as the aerospace industry,surface integrity is one of the most relevant indexes used to evaluate the quality of machined parts.Thus,obtaining updated knowledge on surface integrity is of great interest to both the academic community and industry[1].展开更多
基金“Grassland Talents”of Inner Mongolia Autonomous Region,Young Talents of Science and Technology in Universities of Inner Mongolia Autonomous Region(NJYT23030)Technology Breakthrough Engineering Hydrogen Energy Field“Unveiling and Leading”Project(2024KJTW0018)+3 种基金“Steed Plan High Level Talents”of Inner Mongolia University,Carbon neutralization research project(STZX202218)National Natural Science Foundation of China(U22A20107),Inner Mongolia Autonomous Region Natural Science Foundation(2023MS02002)Guangdong Provincial Key Laboratory of Materials and Technologies for Energy Conversion(MATEC2024KF011)National Key R&D Program of China(2022YFA1205201).
文摘Anion exchange membrane(AEM),as a kind of key membrane materials,has shown great application potential in many electrochemical fields,and remarkable progress has been made in related research in recent years.In this paper,the research status of AEM is reviewed,including its material design,preparation method,performance optimization and application in the fields of hydrogen production by electrolytic water,fuel cell and water treatment.In terms of material design,new polymer skeleton structures are emerging to regulate the stability of ion conduction channels and membranes by introducing specific functional groups or changing the molecular chain structure.The preparation methods have been gradually expanded from the traditional solution casting method to more advanced technologies,such as interfacial polymerization and electrostatic spinning,which effectively improve the microstructure and property uniformity of the film.Performance optimization focuses on improving ion conductivity,reducing membrane swelling rate and enhancing chemical stability,and a variety of modification strategies are developed and applied.Despite the achievements made so far,there are still some challenges,such as the lack of long-term stability in highly alkaline environments.Future research needs to further explore new material systems and preparation processes in order to promote the wide application and sustainable development of AEM technology in energy,environmental protection and other fields.
基金supported by the National Natural Science Foundation of China(22101043)the Fundamental Research Funds for the Central Universities(N2205013,N232410019,N2405013)+3 种基金Natural Science Foundation of Liaoning Province(2023-MSBA-068)the Opening Fund of State Key Laboratory of Heavy Oil Processing(SKLHOP202203006)the Key Laboratory of Functional Molecular Solids,Ministry of Education(FMS2023005)Northeastern University。
文摘The convergence of materials science and biotechnology has catalyzed the development of innovative platforms,including nanotechnology,smart sensors,and supramolecular materials,significantly advancing the progress in the field of life sciences[1−7].Among them,supramolecular materials have garnered increasing attention in life sciences owing to their distinctive self-assembly capabilities and intelligent responsiveness[8−12].
文摘Memory enables organisms to encode,store,and retrieve information essential for interacting with and adapting to a dynamic environment.As an internal representation of the external world,memory serves as a crucial bridge between past experiences and future behaviors.However,the brain continuously forms new memories,raising the question of how new memories are integrated without disrupting previously formed ones.
基金financially supported from the National Natural Science Foundation of China(Nos.52274291,52204305)Beijing Institute of Technology Research Fund Program for Young Scholars,China(No.1740011182102).
文摘The development of low-energy consumption and environmentally friendly electrodeposition of metal/alloy films or coatings is presently one of the primary topics for the research community.For this purpose,deep eutectic solvents(DESs)are valued as electrolytes for their advantages of low operating temperature and wide electrochemical windows.At present,there is large amount of literature on this emerging field,but there are no specialized reviews of these studies.Here,after a brief introduction of DESs’concept and history,we comprehensively reviewed the lastest progress on the metal/alloy electrodeposition in DESs.Additionally,we discussed the key influence factors of the electrodeposition process and analyzed the corresponding mechanisms.Based on these,we emphasized the importance of the establishment of predictive models for dealing with the challenges in large-scale applications.
基金This work was jointly supported by the National Natural Science Foundation of China （Grant Nos. 40633018 40675056）the key project A of the State Ministry of Science and Technology of China ＂South China Sea Monsoon Experiment （SCSMEX）＂.
文摘This paper reviews briefly advances in recent research on monsoon by Chinese scholars, including primarily： （1） the establishment of various monsoon indices. In particular, the standardized dynamic seasonal variability index of the monsoon can delimit the geographical distribution of global monsoon systems and determine quantitatively the date of abrupt change in circulation. （2） The provision of three driving forces for the generation of monsoon. （3） The revelation of the heating-pump action of the Tibetan Plateau, which strengthens southerlies in the southern and southeastern periphery of the Plateau and results in a strong rainfall center from the northern Bay of Bengal （BOB） to the Plateau itself. （4） Clarification of the initial onset of the Asian Summer Monsoon （ASM） in the BOB east of 90°E, Indochina Peninsula （ICP） and the South China Sea, of which the rapid northward progression of tropical convection in the Sumatra and the rapid westward movement of the South Asia High to the Indochina Peninsula are the earliest signs. （5） The provision of an integrated mechanism for the onset of the East Asian Summer Monsoon （EASM）, which emphasizes the integrated impact of sensible heat over Indian Peninsula, the warm advection of the Tibetan Plateau and the sensible heat and latent heat over the Indochina Peninsula on the one hand, and the seasonal phase-lock effect of the northward propagation of low frequency oscillation on the other. （6） The revelation of the ＂planetary-scale moisture transport large-value band＂ from the Southern Hemisphere through to the Asian monsoon region and into the North Pacific, which is converged by several large-scale moisture transport belts in the Asian-Australian monsoon regions and whose variation influences directly the temporal and spatial distribution of summer rainfall in China. （7） Presenting the features of the seasonal advance of the EASM, the propagation of intraseasonal oscillation, and their relationship with rainfall in China; indicating that the intraseasonal oscillation of the EASM propagates in the form of a wave-train along the coast and behaves as monsoon surge propagating northward. （8） Describing the interannual and interdecadal variation of Asian monsoon, revealing the factors affecting it, and possible mechanisms of the variation of Asian monsoon. An elementary outlook on the existing problems and future direction of monsoon research is also provided.
文摘Interest in the possibility of storing and transporting natural gas in the form of clathrate hydrates has been increasing in recent years, particularly in some gas-importing and exporting countries.The technologies necessary for realizing this possibility may be classified into those relevant to the four serial processes (a) the formation of a hydrate, (b) the processing (dewatering, pelletizing, etc. ) of the formed hydrate, (c) the storage and transportation of the processed hydrate, and (d) the regasification (dissociation) of the hydrate. The technological development of any of these processes is still at an early stage. For hydrate formation, for example, various rival operations have been proposed. However,many of them have never been subjected to actual tests for practical use. More efforts are required for examining the different hydrate-formation technologies and for rating them by comparison. The general design of the processing of the formed hydrate inevitably depends on both the hydrate-formation process and the storage/transportation process, hence it has a wide variability. The major uncertainty in the storage-process design lies in the as-yet unclarified utility of the "self-preservation" effect of the naturalgas hydrates. The process design as well as the relevant cost evaluation should strongly depend on whether the hydrates are well preserved at atmospheric pressure in large-scale storage facilities. The regasification process has been studied less extensively than the former processes. The state of the art of the technological development in each of the serial processes is reviewed, placing emphasis on the hydrate formation process.
基金National Natural Science Foundation of China, No.40471007 No.40571007 Knowledge Innovation Project of CAS, No.KZCX2-YW-315-4
文摘Based on historical documents, modern survey and statistics, as well as the result of predecessor studies, the trend and main process of forest dynamics are recognized. The forest area and forest coverage rates for each province of China from 1700 to 1949 are estimated backward by every 50 years. Linking the result with modern National Forest Inventory data, the spatial-temporal dynamics of Chinese forest in recent 300 years （AD 1700-1998） is quantitatively analyzed. The study shows that in recent 300 years, the forest area in current territory of China has declined by 0.95×10^8 hm^2 （or 9.2% of the coverage rate） in total, with a trend of decrease and recovery. Before the 1960s, there was a trend of accelerated descending. The forest area was reduced by 1.66×10^8 hm^2 （or 17% of the coverage rate） in 260 years. While after the 1960s, there has been a rapid increase. The forest area increased by 0.7×10^8 hm^2 （or 8% of the coverage rate） in 40 years. The study also shows that there is a significant spatial difference in the dynamics of forest. The amplitudes of increasing and decreasing in western China are both smaller than the ones in eastern China. During the rapid declining period from 1700 to 1949, the most serious decrease appeared in the Northeast, the Southwest and the Southeast, where the coverage rate in most provinces dropped over 20%. In Heilongjiang Province, the coverage rate dropped by 50%. In Jilin Province, it dropped by 36%. In Sichuan Province and Chongqing Municipality, it dropped by 42%. In Yunnan Province, it dropped by 35%. During the recovery period 1949-1998, the western provinces, municipality and autonomous regions, including Ningxia, Gansu, Inner Mongolia, Sichuan-Chongqing, Yunnan, Tibet, Xinjiang and Qinghai, etc, the increase rates are all below 5%, while the eastern provinces, municipality and autonomous regions （except Heilongjiang, Hubei, Jiangsu-Shanghai） have achieved an increase over 5%, among which the Guangdong-Hainan, Guangxi, Anhui, Beijing-Tianjin-Hebei, Shandong, Henan, Zhejiang, and Fujian have an increase over 10%.
基金financially supported by the National Natural Science Foundation of China(No.51872090,51772097)the Hebei Natural Science Fund for Distinguished Young Scholar(No.E2019209433,E2017209079)the financial support from Hunan Provincial Science and Technology Plan Project of China(No.2016TP1007,2017TP1001,and 2018RS3009)。
文摘The growing demand for energy storage has inspired researchers’exploration of advanced batteries.Aqueous zinc ion batteries(ZIBs)are promising secondary chemical battery system that can be selected and pursued.Rechargeable ZIBs possess merits of high security,low cost,environmental friendliness,and competitive performance,and they are received a lot of attention.However,the development of suitable zinc ion intercalation-type cathode materials is still a big challenge,resulting in failing to meet the commercial needs of ZIBs.Both vanadium-based and manganese-based compounds are representative of the most advanced and most widely used rechargeable ZIBs electrodes.The valence state of vanadium is+2~+5,which can realize multi-electron transfer in the redox reaction and has a high specific capacity.Most of the manganese-based compounds have tunnel structure or three-dimensional space frame,with enough space to accommodate zinc ions.In order to understand the energy storage mechanism and electrochemical performance of these two materials,a specialized review focusing on state-of-the-art developments is needed.This review offers access for researchers to keep abreast of the research progress of cathode materials for ZIBs.The latest advanced researches in vanadium-based and manganese-based cathode materials applied in aqueous ZIBs are highlighted.This article will provide useful guidance for future studies on cathode materials and aqueous ZIBs.
基金the financial support provided by the National Natural Science Foundation of China (Nos. 21822407, 21405163)the top priority program of “OneThree-Five” Strategic Planning of Lanzhou Institute of Chemical Physics, CAS
文摘As a promising signaling transduction approach, fluorescence polarization(FP)/fluorescence anisotropy(FA), provides a powerful quantitative tool for the rotational motion of fluorescently labeled molecules in chemical or biological homogeneous systems. Unlike fluorescence intensity, FP/FA is almost independent the concentration or quantum of fluorophores, but they are highly dependent on the size or molecular weight of the molecules or materials attached to fluorophores. Recently, significant progress in FP/FA was made, due to the introduction of some nanomaterials as FP/FA enhancers. The detection sensitivity is thus greatly improved by using nanomaterials as FP/FA enhancers, and nanomaterial-based FP/FA is currently used successfully in immunoassay, and analysis of protein, nucleic acid, small molecule and metal ion.Nanomaterial-based FP/FA provides a new kind of strategy to design fluorescent sensors and establishes innovative analytical methods. In this review, we summarize the scientific publications in the field of FP/FA sensor in recent five years, and first introduce the recent progress of FP/FA sensor based on nanomaterial. Subsequently, the various analytical applications of FP/FA based on nanomaterial are discussed. Finally, we provide perspectives on the current challenges and future prospects in this promising field.
文摘The technique of endoscopic submucosal dissection(ESD)is now a well-known endoscopic therapy for early gastric cancer.ESD was introduced to resect large specimens of early gastric cancer in a single piece.ESD can provide precision of histologic diagnosis and can also reduce the recurrence rate.However,the drawback of ESD is its technical difficulty,and,consequently,it is associated with a high rate of complications,the need for advanced endoscopic techniques,and a lengthy procedure time.Various advances in the devices and techniques used for ESD have contributed to overcoming these drawbacks.
基金This work is supported by National Natural Science Foundation of China under Grant Nos. 49975013 and 40175019.
文摘This paper summarizes main progresses made in tropical cyclone research field in China in the past few years after the 8th five year program of China. New achievements have been made on tropical cyclone (hereafter referred as TC) structure, numerical prediction, evaluation of operational numerical model, TC–caused heavy rain, TC climate features and disasters, etc.
文摘Recent progress in the production and technology of ductile cast iron castings in China is reviewed. The manufacture and process control of as-cast ductile iron are discussed. The microstructure, properties and application of partial austenitization normalizing ductile iron and austempered ductile iron (ADI) are briefly depicted. The new development of ductile iron production techniques, such as cored-wire injection (wire-feeding nodularization) process, tundish cover ladle nodularizing process, horizontal continuous casting, and EPC process (lost foam) for ductile iron castings, etc., are summarized.
基金National Natural Science Foundation of China, No.G1998040800Chinese Academy of Sciences+1 种基金No.KZCX2-314-2Knowledge Innovation Project of IGSNRR, CAS, No.CXIOG-A1-02
文摘The CC1 core, with a length of 216 cm, was drilled in the west part of the Chen Co (Lake) in southern Tibet Plateau. The210Pb and137Cs measurement indicated that it was a consecutive sedimentary sequence since ca. 1400 years. The ostracoda and their assemblages under the level of 1 cm samples’ cutting interval were finished for this core to reveal the past environmental changes in the lake area. A total of 15 species of ostracods belonging to 7 genera in the core sediments had been identified. According to the ostracod distributions, abundances and preservations in the core, seven ostracod assemblages had been distinguished. The ostracod assemblages and their ecological features, together with the sediments dating decision were used to infer the past ca. 1400 years environmental changes of the Chen Co environmental evolutions in three stages, which had responded to the Medieval Ages Warm-period (MAW), the Little Ice Age (LIA) and modern warm period. The results show that the changes of the Chen Co environment had been mainly influenced by the climatic variations. The trend of the lake level fluctuations had been accorded with that of climatic variation during the past 1400 years.
基金supported by the Ministry of Science and Technology of China National "973" Fundamental Research Program (Grant No.2013CB430103)
文摘1.Introduction Compared with the United States,whose annual number of tornadoes can exceed 1000,the average number of tornadoes per year in China over the past half a century is estimated to be fewer than 100（Fan and Yu,2015）,even though both countries are located in a similar latitudinal zone of the Northern Hemisphere.
基金funded by the National Natural Science Foundation of China(Grant No.91844000)。
文摘Atmospheric chemistry research has been growing rapidly in China in the last 25 years since the concept of the“air pollution complex”was first proposed by Professor Xiaoyan TANG in 1997.For papers published in 2021 on air pollution(only papers included in the Web of Science Core Collection database were considered),more than 24000 papers were authored or co-authored by scientists working in China.In this paper,we review a limited number of representative and significant studies on atmospheric chemistry in China in the last few years,including studies on(1)sources and emission inventories,(2)atmospheric chemical processes,(3)interactions of air pollution with meteorology,weather and climate,(4)interactions between the biosphere and atmosphere,and(5)data assimilation.The intention was not to provide a complete review of all progress made in the last few years,but rather to serve as a starting point for learning more about atmospheric chemistry research in China.The advances reviewed in this paper have enabled a theoretical framework for the air pollution complex to be established,provided robust scientific support to highly successful air pollution control policies in China,and created great opportunities in education,training,and career development for many graduate students and young scientists.This paper further highlights that developing and low-income countries that are heavily affected by air pollution can benefit from these research advances,whilst at the same time acknowledging that many challenges and opportunities still remain in atmospheric chemistry research in China,to hopefully be addressed over the next few decades.
文摘Air pollution has environmental issue owing become a serious to its diverse harmful effects on the physical and biological environment. According to the Environmental Protection Agency （EPA） and the World Health Organization （WHO）, air pollution affects millions of people worldwide. Hundreds of thousands of deaths each year and a range of diseases, particularly among vulnerable groups （i.e., children, the elderly, and people with special medical conditions）, are attributed to air pollution. These effects are not always caused by single pollutant in the air; rather, they are considered consequences of the multi-pollutants to which people are simultaneously exposed.
基金funded by the 863 project(2015AA020502)National Natural Science Foundation of China(61401217,61527806)+1 种基金Natural Science Foundation of Jiangsu Province(BK20140900)the Economical Forest Cultivation and Utilization of 2011 Collaborative Innovation Center in Hunan Province[(2013)448]
文摘Biomedical applications of nanomaterials are exponentially increasing every year due to analogy to various cell receptors, ligands, structural proteins, and genetic materials(that is, DNA). In bone tissue, nanoscale materials can provide scaffold for excellent tissue repair via mechanical stimulation, releasing of various loaded drugs and mediators, 3D scaffold for cell growth and differentiation of bone marrow stem cells to osteocytes. This review will therefore highlight recent advancements on tissue and nanoscale materials interaction.
文摘1.Introduction Surface integrity has great significance for the quality and performance of machined components,and has therefore been increasingly recognized by industry.In particular,within certain industries that require high reliability,such as the aerospace industry,surface integrity is one of the most relevant indexes used to evaluate the quality of machined parts.Thus,obtaining updated knowledge on surface integrity is of great interest to both the academic community and industry[1].
