Metal organic frameworks（MOFs） are considered as very promising candidates to build electrodes for electrochemical energy storage devices such as lithium ion batteries, fuel cells and supercapacitors, due to their d...Metal organic frameworks（MOFs） are considered as very promising candidates to build electrodes for electrochemical energy storage devices such as lithium ion batteries, fuel cells and supercapacitors, due to their diverse structure, adjustable aperture, large specific surface area and abundant active sites. Supercapacitor has been widely investigated in the past decades. Of critical importance in these devices is the electrode active materials, and this application has been intensively studied with the development of novel nanomaterials. In this review we summarize recent reports on MO Fs as electrode materials for super capacitors. Specifically,the synthesis of MOF materials for super capacitor electrodes and their performance in electrochemical energy storage are discussed. We aim to include supercapacitor electrode materials related to MOFs, such as carbon, metal and composite materials. It is proposed that MOFs play an important role in the development of a new generation of supercapacitor electrode materials. Finally, we discuss the current challenges in the field of supercapacitors, with a view towards how to address these challenges with the future development of MOFs and their derivatives.展开更多
The individual and combined effects of biochar(B)and inorganic fertiliser(F)have all been widely proofed to improve soil fertility and enhance crop growth and yield under irrigation(I)and rain fed conditions.However,t...The individual and combined effects of biochar(B)and inorganic fertiliser(F)have all been widely proofed to improve soil fertility and enhance crop growth and yield under irrigation(I)and rain fed conditions.However,the strength of their individual and combined effects on crop productivity has been scarcely reported.In addition,few studies have assessed their individual and co-application effects on economic returns.Therefore,a 2-year field experiment which consisted of factorial combination of irrigation(I)[100%full irrigation(FI),80%FI and 60%FI],biochar(0 and 20 t/ha)and fertiliser(0 and 300 kg/ha)was conducted.According to the results,irrigation was the dominant factor that influences maize grain yield,followed by inorganic fertiliser and biochar,and they were all significant in their main effects.The strength of interaction effects among,I,F and B on maize grain yield follow the sequence F×I>B×F>B×I.The economic analysis showed that the ternary combination of B,F and I was more economical than the binary combination of B plus I,and F plus I(in that order),when compared with the standalone application of I at maximum production in the field experiment.In addition,combined applications of biochar and fertiliser improved soil nutrients,nutrient uptake in all irrigation treatments,compared to the standalone applications of biochar or fertiliser.Further research is,therefore,recommended for long-term evaluation of the economic viability of integrating biochar with fertiliser under irrigation.展开更多
人们首次听说“网络公开课”（Massive Open Online Courses）的名字是在本世纪初。从2001年起，耶鲁、剑桥、麻省理工学院等一批世界顶尖高校纷纷将自己的课程公布到网上。如此“慷慨”的知识共享不光让世界各地的学生近距离地领略到...人们首次听说“网络公开课”（Massive Open Online Courses）的名字是在本世纪初。从2001年起，耶鲁、剑桥、麻省理工学院等一批世界顶尖高校纷纷将自己的课程公布到网上。如此“慷慨”的知识共享不光让世界各地的学生近距离地领略到国外名校教授的人文内涵与学术魅力，更是掀起了教育史上继远程函授之后的又一次革命。本文从商业中的“颠覆性创新”角度出发，另类解读网络公开课的现状与未来。展开更多
Hydrogel encapsulation has been widely utilized in the study of fundamental cellular mechanisms and has been shown to provide a better representation of the complex in vivo microenvironment in natural biological condi...Hydrogel encapsulation has been widely utilized in the study of fundamental cellular mechanisms and has been shown to provide a better representation of the complex in vivo microenvironment in natural biological conditions of mammalian cells.In this review,we provide a background into the adoption of hydrogel encapsulation methods in the study of mammalian cells,highlight some key findings that may aid with the adoption of similar methods for the study of plant cells,including the potential challenges and considerations,and discuss key findings of studies that have utilized these methods in plant sciences.展开更多
Linked to major volcanic eruptions around 536 and 540 CE, the onset of the Late Antique Little Ice Age has been described as the coldest period of the past two millennia. The exact timing and spatial extent of this ex...Linked to major volcanic eruptions around 536 and 540 CE, the onset of the Late Antique Little Ice Age has been described as the coldest period of the past two millennia. The exact timing and spatial extent of this exceptional cold phase are, however, still under debate because of the limited resolution and geographical distribution of the available proxy archives. Here, we use 106 wood anatomical thin sections from 23forest sites and 20 tree species in both hemispheres to search for cell-level fingerprints of ephemeral summer cooling between 530 and 550 CE. After cross-dating and double-staining, we identified 89Blue Rings(lack of cell wall lignification), nine Frost Rings(cell deformation and collapse), and 93Light Rings(reduced cell wall thickening) in the Northern Hemisphere. Our network reveals evidence for the strongest temperature depression between mid-July and early-August 536 CE across North America and Eurasia, whereas more localised cold spells occurred in the summers of 532, 540–43, and548 CE. The lack of anatomical signatures in the austral trees suggests limited incursion of stratospheric volcanic aerosol into the Southern Hemisphere extra-tropics, that any forcing was mitigated by atmosphere-ocean dynamical responses and/or concentrated outside the growing season, or a combination of factors. Our findings demonstrate the advantage of wood anatomical investigations over traditional dendrochronological measurements, provide a benchmark for Earth system models, support cross-disciplinary studies into the entanglements of climate and history, and question the relevance of global climate averages.展开更多
基金supported by the Fundamental Research Funds for Central Universities' through Beihang Universitythe Queensland Government through the Q-CAS Collaborative Science Fund 2016 "Graphene-Based Thin Film Supercapacitors"
文摘Metal organic frameworks（MOFs） are considered as very promising candidates to build electrodes for electrochemical energy storage devices such as lithium ion batteries, fuel cells and supercapacitors, due to their diverse structure, adjustable aperture, large specific surface area and abundant active sites. Supercapacitor has been widely investigated in the past decades. Of critical importance in these devices is the electrode active materials, and this application has been intensively studied with the development of novel nanomaterials. In this review we summarize recent reports on MO Fs as electrode materials for super capacitors. Specifically,the synthesis of MOF materials for super capacitor electrodes and their performance in electrochemical energy storage are discussed. We aim to include supercapacitor electrode materials related to MOFs, such as carbon, metal and composite materials. It is proposed that MOFs play an important role in the development of a new generation of supercapacitor electrode materials. Finally, we discuss the current challenges in the field of supercapacitors, with a view towards how to address these challenges with the future development of MOFs and their derivatives.
基金We appreciate the research grant from the Tertiary Education Trust Fund(TETFUND)Nigeria,which was used to fund part of this research.
文摘The individual and combined effects of biochar(B)and inorganic fertiliser(F)have all been widely proofed to improve soil fertility and enhance crop growth and yield under irrigation(I)and rain fed conditions.However,the strength of their individual and combined effects on crop productivity has been scarcely reported.In addition,few studies have assessed their individual and co-application effects on economic returns.Therefore,a 2-year field experiment which consisted of factorial combination of irrigation(I)[100%full irrigation(FI),80%FI and 60%FI],biochar(0 and 20 t/ha)and fertiliser(0 and 300 kg/ha)was conducted.According to the results,irrigation was the dominant factor that influences maize grain yield,followed by inorganic fertiliser and biochar,and they were all significant in their main effects.The strength of interaction effects among,I,F and B on maize grain yield follow the sequence F×I>B×F>B×I.The economic analysis showed that the ternary combination of B,F and I was more economical than the binary combination of B plus I,and F plus I(in that order),when compared with the standalone application of I at maximum production in the field experiment.In addition,combined applications of biochar and fertiliser improved soil nutrients,nutrient uptake in all irrigation treatments,compared to the standalone applications of biochar or fertiliser.Further research is,therefore,recommended for long-term evaluation of the economic viability of integrating biochar with fertiliser under irrigation.
文摘人们首次听说“网络公开课”（Massive Open Online Courses）的名字是在本世纪初。从2001年起，耶鲁、剑桥、麻省理工学院等一批世界顶尖高校纷纷将自己的课程公布到网上。如此“慷慨”的知识共享不光让世界各地的学生近距离地领略到国外名校教授的人文内涵与学术魅力，更是掀起了教育史上继远程函授之后的又一次革命。本文从商业中的“颠覆性创新”角度出发，另类解读网络公开课的现状与未来。
基金supported by the NSF EAGER grant(MCB#2039285)to TJH and RS.
文摘Hydrogel encapsulation has been widely utilized in the study of fundamental cellular mechanisms and has been shown to provide a better representation of the complex in vivo microenvironment in natural biological conditions of mammalian cells.In this review,we provide a background into the adoption of hydrogel encapsulation methods in the study of mammalian cells,highlight some key findings that may aid with the adoption of similar methods for the study of plant cells,including the potential challenges and considerations,and discuss key findings of studies that have utilized these methods in plant sciences.
基金funding from the ERC Advanced Project MONOSTAR (Ad G 882727)funding from Sust ES: adaptation strategies for sustainable ecosystem services and food security under adverse environmental conditions (CZ.02.1.01/0.0/0.0/16_0 19/0000797)+11 种基金funding from the Fritz & Elisabeth Schweingruber Foundation. Duncan A. Christie and Carlos Le Quesne received funding from the ANID (FONDECYT 1201411, 1221307, FONDAP 15110009, BASAL FB210018)funding from the Russian Science Foundation grant (RSF 21-17-00006)funding from NSF Arctic Social Science 2112314NSF Arctic Natural Science 2124885the NSF P2C2 (Paleo Perspectives on Climatic Change) program (various grants)funding from the Russian Science Foundation grant (RSF 21-1400330)funding from the Russian Science Foundation grant (RSF 18-14-00072P)supported by the Swedish Research Council (201801272)funding from the Swiss National Science Foundation through the SNSF Sinergia CALDERA project (CRSII5 183571)funding from the National Science Foundation’s P2C2 Program (1902625 and 1203749)the Malcolm H.Wiener Foundationfunded through NSF P2C2 Program (2002454)
文摘Linked to major volcanic eruptions around 536 and 540 CE, the onset of the Late Antique Little Ice Age has been described as the coldest period of the past two millennia. The exact timing and spatial extent of this exceptional cold phase are, however, still under debate because of the limited resolution and geographical distribution of the available proxy archives. Here, we use 106 wood anatomical thin sections from 23forest sites and 20 tree species in both hemispheres to search for cell-level fingerprints of ephemeral summer cooling between 530 and 550 CE. After cross-dating and double-staining, we identified 89Blue Rings(lack of cell wall lignification), nine Frost Rings(cell deformation and collapse), and 93Light Rings(reduced cell wall thickening) in the Northern Hemisphere. Our network reveals evidence for the strongest temperature depression between mid-July and early-August 536 CE across North America and Eurasia, whereas more localised cold spells occurred in the summers of 532, 540–43, and548 CE. The lack of anatomical signatures in the austral trees suggests limited incursion of stratospheric volcanic aerosol into the Southern Hemisphere extra-tropics, that any forcing was mitigated by atmosphere-ocean dynamical responses and/or concentrated outside the growing season, or a combination of factors. Our findings demonstrate the advantage of wood anatomical investigations over traditional dendrochronological measurements, provide a benchmark for Earth system models, support cross-disciplinary studies into the entanglements of climate and history, and question the relevance of global climate averages.
