We report on the formation of two-dimensional monolayer AgTe crystal on Ag(111) substrates. The samples are prepared in ultrahigh vacuum by deposition of Te on Ag(111) followed by annealing. Using a scanning tunneling...We report on the formation of two-dimensional monolayer AgTe crystal on Ag(111) substrates. The samples are prepared in ultrahigh vacuum by deposition of Te on Ag(111) followed by annealing. Using a scanning tunneling microscope(STM) and low electron energy diffraction(LEED), we investigate the atomic structure of the samples.The STM images and the LEED pattern show that monolayer AgTe crystal is formed on Ag(111). Four kinds of atomic structures of AgTe and Ag(111) are observed:(i) flat honeycomb structure,(ii) bulked honeycomb,(iii)stripe structure,(iv) hexagonal structure. The structural analysis indicates that the formation of the different atomic structures is due to the lattice mismatch and relief of the intrinsic strain in the AgTe layer. Our results provide a simple and convenient method to produce monolayer AgTe atomic crystal on Ag(111) and a template for study of novel physical properties and for future quantum devices.展开更多
Transition-metal chalcogenides(TMCs)materials have attracted increasing interest both for fundamental research and industrial applications.Among all these materials,two-dimensional(2D)compounds with honeycomb-like str...Transition-metal chalcogenides(TMCs)materials have attracted increasing interest both for fundamental research and industrial applications.Among all these materials,two-dimensional(2D)compounds with honeycomb-like structure possess exotic electronic structures.Here,we report a systematic study of TMC monolayer AgTe fabricated by direct depositing Te on the surface of Ag(111)and annealing.Few intrinsic defects are observed and studied by scanning tunneling microscopy,indicating that there are two kinds of AgTe domains and they can form gliding twin-boundary.Then,the monolayer AgTe can serve as the template for the following growth of Te film.Meanwhile,some Te atoms are observed in the form of chains on the top of the bottom Te film.Our findings in this work might provide insightful guide for the epitaxial growth of 2D materials for study of novel physical properties and for future quantum devices.展开更多
Genetic polymorphism has a vital role in the pathogenesis and development of myocardial infarction(MI).Single nucleotide polymorphism at any one of the amino acid sequences can result in a diseased state.A single gene...Genetic polymorphism has a vital role in the pathogenesis and development of myocardial infarction(MI).Single nucleotide polymorphism at any one of the amino acid sequences can result in a diseased state.A single gene can exhibit genetic polymorphism at more than one position giving rise to different variants.Genetic polymorphism of angiotensinogen(AGT)M235T,AGT T174M,and angiotensin-1-converting enzyme(ACE)I/D,endothelial nitric oxide synthase(eNOS),and methylenetetrahydrofolate reductase(MTHFR)can be a risk factor for MI.However,it is important to study the prevalence of genetic polymorphisms of these genes among different populations.MI is influenced by genetic polymorphism of various genes,including AGT,ACE,eNOS,MTHFR,etc.However,the association of genetic polymorphism of these genes varies among different populations,but different ethnic groups could show contradictory results.These genes have shown a positive association with risks of MI in some populations,whereas the results have not been consistent with every ethnic group.In this article,we have summarized the genetic variations in the aforementioned genes and their association with MI.展开更多
基金Supported by the National Key Research&Development Projects of China under Grant Nos 2016YFA0202300 and 2018FYA0305800the National Natural Science Foundation of China under Grant Nos 61390501,61474141 and 11604373+1 种基金the CAS Pioneer Hundred Talents Programthe Strategic Priority Research Program of Chinese Academy of Sciences under Grant No XDB28000000
文摘We report on the formation of two-dimensional monolayer AgTe crystal on Ag(111) substrates. The samples are prepared in ultrahigh vacuum by deposition of Te on Ag(111) followed by annealing. Using a scanning tunneling microscope(STM) and low electron energy diffraction(LEED), we investigate the atomic structure of the samples.The STM images and the LEED pattern show that monolayer AgTe crystal is formed on Ag(111). Four kinds of atomic structures of AgTe and Ag(111) are observed:(i) flat honeycomb structure,(ii) bulked honeycomb,(iii)stripe structure,(iv) hexagonal structure. The structural analysis indicates that the formation of the different atomic structures is due to the lattice mismatch and relief of the intrinsic strain in the AgTe layer. Our results provide a simple and convenient method to produce monolayer AgTe atomic crystal on Ag(111) and a template for study of novel physical properties and for future quantum devices.
基金This project was supported by the Ministry of Science and Technology(MOST)of China(No.2016YFA0200700)the National Natural Science Foundation of China(NSFC)(Nos.61674045 and 61911540074)+2 种基金the Strategic Priority Research Program and Key Research Program of Frontier Sciences(Chinese Academy of Sciences,CAS)(Nos.XDB30000000 and QYZDB-SSW-SYS031)Grant-in-Aid for Scientific Research from Japan Society for the Promotion of Science(JSPS)from the Ministry of Education,Culture,Sports,Science,and Technology of Japan(Nos.JP16H06327,JP16H06504,JP17H01061,and JP17H010610)Osaka University’s International Joint Research Promotion Program(Nos.J171013014,J171013007,J181013006,and Ja19990011).Z.H.C.was supported by the Fundamental Research Funds for the Central Universities and the Research Funds of Renmin University of China(No.21XNLG27).
文摘Transition-metal chalcogenides(TMCs)materials have attracted increasing interest both for fundamental research and industrial applications.Among all these materials,two-dimensional(2D)compounds with honeycomb-like structure possess exotic electronic structures.Here,we report a systematic study of TMC monolayer AgTe fabricated by direct depositing Te on the surface of Ag(111)and annealing.Few intrinsic defects are observed and studied by scanning tunneling microscopy,indicating that there are two kinds of AgTe domains and they can form gliding twin-boundary.Then,the monolayer AgTe can serve as the template for the following growth of Te film.Meanwhile,some Te atoms are observed in the form of chains on the top of the bottom Te film.Our findings in this work might provide insightful guide for the epitaxial growth of 2D materials for study of novel physical properties and for future quantum devices.
基金the support of the Research Center for Advanced Materials Science(RCAMS)at King Khalid University Abha,Saudi Arabia,through Grant(KKU/RCAMS/22).
文摘Genetic polymorphism has a vital role in the pathogenesis and development of myocardial infarction(MI).Single nucleotide polymorphism at any one of the amino acid sequences can result in a diseased state.A single gene can exhibit genetic polymorphism at more than one position giving rise to different variants.Genetic polymorphism of angiotensinogen(AGT)M235T,AGT T174M,and angiotensin-1-converting enzyme(ACE)I/D,endothelial nitric oxide synthase(eNOS),and methylenetetrahydrofolate reductase(MTHFR)can be a risk factor for MI.However,it is important to study the prevalence of genetic polymorphisms of these genes among different populations.MI is influenced by genetic polymorphism of various genes,including AGT,ACE,eNOS,MTHFR,etc.However,the association of genetic polymorphism of these genes varies among different populations,but different ethnic groups could show contradictory results.These genes have shown a positive association with risks of MI in some populations,whereas the results have not been consistent with every ethnic group.In this article,we have summarized the genetic variations in the aforementioned genes and their association with MI.
