As a new type of two-dimensional(2D)materials,monoelemental 2D materials have the atomic structure similar to graphene,and their excellent optical and electronic properties have potential applications in many fields.T...As a new type of two-dimensional(2D)materials,monoelemental 2D materials have the atomic structure similar to graphene,and their excellent optical and electronic properties have potential applications in many fields.To date,many studies based on monoelemental 2D materials have been reported,and excellent performance has been demonstrated in various fields.The monoelemental 2D materials that have been reported so far are mainly distributed in the groupⅢA,ⅣA,ⅤA,andⅥA.Because of their structural similarities to graphene,they are commonly referred to as"Xenes."Here,we have comprehensively reviewed the research progress of monoelemental 2D materials.In this review,we explore the structure,properties,and practical applications of these monoelemental 2D materials.First,the classification,structural features,optical properties,electronic characteristics,and regulating mechanism of these monoelemental 2D materials are introduced.Then,the practical application and research progress of monoelemental 2D materials in various fields are reviewed comprehensively,especially including photoelectric catalysis,solar cells,and other energy fields.This review will give readers a more all-sided understanding of monoelemental 2D materials and have some guiding significance for their further development.展开更多
The gut microbiota is involved in host responses to high altitude.However,the dynamics of intestinal microecology and their association with altitude-related illness are poorly understood.Here,we used a rat model of h...The gut microbiota is involved in host responses to high altitude.However,the dynamics of intestinal microecology and their association with altitude-related illness are poorly understood.Here,we used a rat model of hypobaric hypoxia challenge to mimic plateau exposure and monitored the gut microbiome,short-chain fatty acids(SCFAs),and bile acids(BAs)over 28 d.We identified weight loss,polycythemia,and pathological cardiac hypertrophy in hypoxic rats,accompanied by a large compositional shift in the gut microbiota,which is mainly driven by the bacterial families of Prevotellaceae,Porphyromonadaceae,and Streptococcaceae.The aberrant gut microbiota was characterized by increased abundance of the Parabacteroides,Alistipes,and Lactococcus genera and a larger Bacteroides to Prevotella ratio.Trans-omics analyses showed that the gut microbiome was significantly correlated with the metabolic abnormalities of SCFAs and BAs in feces,suggesting an interaction network remodeling of the microbiome-metabolome after the hypobaric hypoxia challenge.Interestingly,the transplantation of fecal microbiota significantly increased the diversity of the gut microbiota,partially inhibited the increased abundance of the Bacteroides and Alistipes genera,restored the decrease of plasma propionate,and moderately ameliorated cardiac hypertrophy in hypoxic rats.Our results provide an insight into the longitudinal changes in intestinal microecology during the hypobaric hypoxia challenge.Abnormalities in the gut microbiota and microbial metabolites contribute to the development of high-altitude heart disease in rats.展开更多
We experimentally investigated the nonlinear optical response in few-layer oxidized black phosphorus(OBP) by the femtosecond Z-scan measurement technique, and found that OBP not only possesses strong ultrafast saturab...We experimentally investigated the nonlinear optical response in few-layer oxidized black phosphorus(OBP) by the femtosecond Z-scan measurement technique, and found that OBP not only possesses strong ultrafast saturable absorption but also a nonlinear self-defocusing effect that is absent in black phosphorus(BP). The saturable absorption property originates mainly from the direct band structure, which is still maintained in OBP. The emergence of self-defocusing might originate from the combined consequences of the oxygen-induced defects in BP. Our experimental findings might constitute the first experimental evidence on how to dynamically tune its nonlinear property, offering an inroad in tailoring its optical properties through chemical modification(oxidation, introducing defects, etc.). The versatile ultrafast nonlinear optical properties(saturable absorption and self-defocusing) imply a significant potential of the layered OBP in the development of unprecedented optoelectronic devices, such as mode lockers, optical switches, laser beam shapers, and wavelength converters.展开更多
基金supported by the Grants from Provincial Natural Science Foundation of Hunan(No.2019JJ50612)Open Fund Based on Innovation Platform of Hunan Col eges and Universities(No.18K032)+3 种基金National Natural Science Foundation of China(No.11504312)Scientific Research Fund of Hunan Provincial Education Department(No.18A059)the Program for Changjiang Scholars and Innovative Research Team in University(IRT_17R91)Science and Technology Program of Xiangtan(No.CXYZD20172002)
文摘As a new type of two-dimensional(2D)materials,monoelemental 2D materials have the atomic structure similar to graphene,and their excellent optical and electronic properties have potential applications in many fields.To date,many studies based on monoelemental 2D materials have been reported,and excellent performance has been demonstrated in various fields.The monoelemental 2D materials that have been reported so far are mainly distributed in the groupⅢA,ⅣA,ⅤA,andⅥA.Because of their structural similarities to graphene,they are commonly referred to as"Xenes."Here,we have comprehensively reviewed the research progress of monoelemental 2D materials.In this review,we explore the structure,properties,and practical applications of these monoelemental 2D materials.First,the classification,structural features,optical properties,electronic characteristics,and regulating mechanism of these monoelemental 2D materials are introduced.Then,the practical application and research progress of monoelemental 2D materials in various fields are reviewed comprehensively,especially including photoelectric catalysis,solar cells,and other energy fields.This review will give readers a more all-sided understanding of monoelemental 2D materials and have some guiding significance for their further development.
基金supported by the National Natural Science Foundation of China(81790632,31970863,and 31970088)the National Key Technology Research and Development Program of the Ministry of Science and Technology of China(2020YFA0509600)。
文摘The gut microbiota is involved in host responses to high altitude.However,the dynamics of intestinal microecology and their association with altitude-related illness are poorly understood.Here,we used a rat model of hypobaric hypoxia challenge to mimic plateau exposure and monitored the gut microbiome,short-chain fatty acids(SCFAs),and bile acids(BAs)over 28 d.We identified weight loss,polycythemia,and pathological cardiac hypertrophy in hypoxic rats,accompanied by a large compositional shift in the gut microbiota,which is mainly driven by the bacterial families of Prevotellaceae,Porphyromonadaceae,and Streptococcaceae.The aberrant gut microbiota was characterized by increased abundance of the Parabacteroides,Alistipes,and Lactococcus genera and a larger Bacteroides to Prevotella ratio.Trans-omics analyses showed that the gut microbiome was significantly correlated with the metabolic abnormalities of SCFAs and BAs in feces,suggesting an interaction network remodeling of the microbiome-metabolome after the hypobaric hypoxia challenge.Interestingly,the transplantation of fecal microbiota significantly increased the diversity of the gut microbiota,partially inhibited the increased abundance of the Bacteroides and Alistipes genera,restored the decrease of plasma propionate,and moderately ameliorated cardiac hypertrophy in hypoxic rats.Our results provide an insight into the longitudinal changes in intestinal microecology during the hypobaric hypoxia challenge.Abnormalities in the gut microbiota and microbial metabolites contribute to the development of high-altitude heart disease in rats.
基金National Natural Science Foundation of China(NSFC)(61435010,61505117)Science and Technology Innovation Commission of Shenzhen(KQTD2015032416270385)+1 种基金China Postdoctoral Science Foundation(2015M580731)Scienceand Technology Planning Project of Guangdong Province(2016B050501005)
文摘We experimentally investigated the nonlinear optical response in few-layer oxidized black phosphorus(OBP) by the femtosecond Z-scan measurement technique, and found that OBP not only possesses strong ultrafast saturable absorption but also a nonlinear self-defocusing effect that is absent in black phosphorus(BP). The saturable absorption property originates mainly from the direct band structure, which is still maintained in OBP. The emergence of self-defocusing might originate from the combined consequences of the oxygen-induced defects in BP. Our experimental findings might constitute the first experimental evidence on how to dynamically tune its nonlinear property, offering an inroad in tailoring its optical properties through chemical modification(oxidation, introducing defects, etc.). The versatile ultrafast nonlinear optical properties(saturable absorption and self-defocusing) imply a significant potential of the layered OBP in the development of unprecedented optoelectronic devices, such as mode lockers, optical switches, laser beam shapers, and wavelength converters.