Transition metal ditellurides(TMTDs)have versatile physical properties,including non-trivial topology,Weyl semimetal states and unique spin texture.Controlled growth of high-quality and large-scale monolayer TMTDs wit...Transition metal ditellurides(TMTDs)have versatile physical properties,including non-trivial topology,Weyl semimetal states and unique spin texture.Controlled growth of high-quality and large-scale monolayer TMTDs with preferred crystal phases is crucial for their applications.Here,we demonstrate the epitaxial growth of 1T'-MoTe_(2) on Au(111)and graphitized silicon carbide(Gr/SiC)by molecular beam epitaxy(MBE).We investigate the morphology of the grown1T'-MoTe_(2) at the atomic level by scanning tunnelling microscopy(STM)and reveal the corresponding microscopic growth mechanism.It is found that the unique ordered Te structures preferentially deposited on Au(111)regulate the growth of monolayer single crystal 1T'-MoTe_(2),while the Mo clusters were preferentially deposited on the Gr/SiC substrate,which impedes the ordered growth of monolayer MoTe_(2).We confirm that the size of single crystal 1T'-MoTe_(2) grown on Au(111)is nearly two orders of magnitude larger than that on Gr/SiC.By scanning tunnelling spectroscopy(STS),we observe that the STS spectrum of the monolayer 1T'-MoTe_(2) nano-island at the edge is different from that at the interior,which exhibits enhanced conductivity.展开更多
The paper introduces a Special Issue based on presentations to the Agricultural Geography and Land Engineering(AGLE)Commission sessions of the International Geographical Union(IGU)at the IGU’s Congress in Paris in 20...The paper introduces a Special Issue based on presentations to the Agricultural Geography and Land Engineering(AGLE)Commission sessions of the International Geographical Union(IGU)at the IGU’s Congress in Paris in 2022.The sessions contrasted different approaches towards attaining greater sustainability in agricultural production to satisfy the need to feed the ever-increasing human population,currently expected to reach close to ten billion by 2050.After considering the multi-faceted problem of defining sustainable agriculture,this introduction systematically outlines broad strategies to attain the varied outcomes desired by agricultural systems.Presenting a contrast between ecocentric and technocentric approaches provides opportunities to synthesize recent literature addressing the pros and cons of these two broad alternatives.Recognition of the ecological and socio-cultural benefits accruing from the ecocentric has long been championed by proponents of a wide range of environmentally friendly farming systems,including organic farming,climate-smart agriculture,agroforestry,and permaculture.The technocentric lies at the heart of so-called Agriculture 4.0,in which innovations such as precision farming,digital technology,and genetic modification are applied to increase production per unit area.The potential for technology to‘solve’the world’s food crisis is supported by those who argue that ecocentric approaches alone cannot meet the rising demand for food.Yet,questions remain about the sustainability of new technology-based methods,so a strong and ongoing debate continues regarding how to attain greater sustainability alongside increasing agricultural output.This debate is exemplified in the contributions to the Special Issue outlined herewith.展开更多
Introduction,L’histoire de la démocratie sanitaire-devenue par un glissement sémantique la démocratie en santé-est un long processus encore et toujours en marche de la relation entre les citoyens ...Introduction,L’histoire de la démocratie sanitaire-devenue par un glissement sémantique la démocratie en santé-est un long processus encore et toujours en marche de la relation entre les citoyens et leur système de santé[1,2].Cette relation aétéet continue d’être influencée par des changements sociétaux majeurs au cours des dernières décennies.展开更多
基金Project supported by the National Key R&D Program of China (Grant No.2022YFA1204302)the National Natural Science Foundation of China (Grant Nos.52022029,52221001,92263107,U23A20570,62090035,U19A2090,and 12174098)+1 种基金the Hunan Provincial Natural Science Foundation of China (Grant Nos.2022JJ30142 and 2019XK2001)in part supported by the State Key Laboratory of Powder Metallurgy,Central South University。
文摘Transition metal ditellurides(TMTDs)have versatile physical properties,including non-trivial topology,Weyl semimetal states and unique spin texture.Controlled growth of high-quality and large-scale monolayer TMTDs with preferred crystal phases is crucial for their applications.Here,we demonstrate the epitaxial growth of 1T'-MoTe_(2) on Au(111)and graphitized silicon carbide(Gr/SiC)by molecular beam epitaxy(MBE).We investigate the morphology of the grown1T'-MoTe_(2) at the atomic level by scanning tunnelling microscopy(STM)and reveal the corresponding microscopic growth mechanism.It is found that the unique ordered Te structures preferentially deposited on Au(111)regulate the growth of monolayer single crystal 1T'-MoTe_(2),while the Mo clusters were preferentially deposited on the Gr/SiC substrate,which impedes the ordered growth of monolayer MoTe_(2).We confirm that the size of single crystal 1T'-MoTe_(2) grown on Au(111)is nearly two orders of magnitude larger than that on Gr/SiC.By scanning tunnelling spectroscopy(STS),we observe that the STS spectrum of the monolayer 1T'-MoTe_(2) nano-island at the edge is different from that at the interior,which exhibits enhanced conductivity.
文摘The paper introduces a Special Issue based on presentations to the Agricultural Geography and Land Engineering(AGLE)Commission sessions of the International Geographical Union(IGU)at the IGU’s Congress in Paris in 2022.The sessions contrasted different approaches towards attaining greater sustainability in agricultural production to satisfy the need to feed the ever-increasing human population,currently expected to reach close to ten billion by 2050.After considering the multi-faceted problem of defining sustainable agriculture,this introduction systematically outlines broad strategies to attain the varied outcomes desired by agricultural systems.Presenting a contrast between ecocentric and technocentric approaches provides opportunities to synthesize recent literature addressing the pros and cons of these two broad alternatives.Recognition of the ecological and socio-cultural benefits accruing from the ecocentric has long been championed by proponents of a wide range of environmentally friendly farming systems,including organic farming,climate-smart agriculture,agroforestry,and permaculture.The technocentric lies at the heart of so-called Agriculture 4.0,in which innovations such as precision farming,digital technology,and genetic modification are applied to increase production per unit area.The potential for technology to‘solve’the world’s food crisis is supported by those who argue that ecocentric approaches alone cannot meet the rising demand for food.Yet,questions remain about the sustainability of new technology-based methods,so a strong and ongoing debate continues regarding how to attain greater sustainability alongside increasing agricultural output.This debate is exemplified in the contributions to the Special Issue outlined herewith.
文摘Introduction,L’histoire de la démocratie sanitaire-devenue par un glissement sémantique la démocratie en santé-est un long processus encore et toujours en marche de la relation entre les citoyens et leur système de santé[1,2].Cette relation aétéet continue d’être influencée par des changements sociétaux majeurs au cours des dernières décennies.
