We review the themes relating to the proposition that“quantization commutes with reduction”([Q,R]=0),from symplectic manifolds to Cauchy-Riemann manifolds.
Mechanochromophores based on bichromic molecular switches,such as bis-naphthopyanes,allow multimodal mechanochromic behavior beyond the typical binary response from single chromophores,which is important for distingui...Mechanochromophores based on bichromic molecular switches,such as bis-naphthopyanes,allow multimodal mechanochromic behavior beyond the typical binary response from single chromophores,which is important for distinguishing between multiple stress states through discrete changes in color.Spontaneously generated persistent and distinguishable multi-colors from activated bis-naphthopyanes remain challenging.And the versatility of bis-mechanophore design for advanced optical molecular systems and the fundamental insights into the corresponding mechano-reactivity are not enough.Here,we identify a dihydroanthracene bridged bis-naphthopyrans as a multimodal mechanochromophore in polymers.Bridging two pyrans with the sterically constrained dihydroanthracene is helpful to control the steric effect for the favorable formation of a distinctly appreciable bis-merocyanine(bis-MC)product.By varying the length of the polymer chains,the force delivered to the mechanophore is modulated,resulting in a gradient change in the relative distribution of two distinctly colored MC products and a multicolor mechanochromism.Mechanical activation of this bis-naphthopyanes proceeds via a mechanistically distinct pathway compared to the photochemical process.In addition,the bulk films can also achieve pronounced color changes when subjected to mechanical force.This study thus further expands the molecular diversity of mechanochromophores and tune the multimodal switch properties of bis-naphthopyrans based polymers.展开更多
Vertical ferroelectricity where a net dipole moment appears as a result of in-plane ionic displacements has gained enormous attention following its discovery in transition metal dichalcogenides.Based on first-principl...Vertical ferroelectricity where a net dipole moment appears as a result of in-plane ionic displacements has gained enormous attention following its discovery in transition metal dichalcogenides.Based on first-principles calculations,we report on the evidence of robust vertical ferroelectricity upon interlayer sliding in layered semiconductingβ-ZrI_(2),a sister material of polar semimetals MoTe_(2)and WTe_(2).The microscopic origin of ferroelectricity in ZrI_(2)is attributed to asymmetric shifts of electronic charges within a trilayer,revealing a subtle interplay of rigid sliding displacements and charge redistribution down to ultrathin thicknesses.We further investigate the variety of ferroelectric domain boundaries and predict a stable charged domain wall with a quasi-twodimensional electron gas and a high built-in electric field that can increase electron mobility and electromechanical response in multifunctional devices.Semiconducting behaviour and a small switching barrier of ZrI_(2)hold promise for various ferroelectric applications,and our results provide important insights for further development of slidetronics ferroelectricity.展开更多
In this short note,we compare our previous work on the off-diagonal expansion of the Bergman kernel and the preprint of Lu-Shiffman(arXiv:1301.2166).In particular,we note that the vanishing of the coefficient of p−1/2...In this short note,we compare our previous work on the off-diagonal expansion of the Bergman kernel and the preprint of Lu-Shiffman(arXiv:1301.2166).In particular,we note that the vanishing of the coefficient of p−1/2 is implicitly contained in Dai-Liu-Ma’s work(J.Differ.Geom.72(1),1-41,2006)and was explicitly stated in our book(Holomorphic Morse inequalities and Bergman kernels.Progress in Math.,vol.254,2007).展开更多
The gut microbiota refers to the gross collection of microorganisms,estimated trillions of them,which reside within the gut and play crucial roles in the absorption and digestion of dietary nutrients.In the past decad...The gut microbiota refers to the gross collection of microorganisms,estimated trillions of them,which reside within the gut and play crucial roles in the absorption and digestion of dietary nutrients.In the past decades,the new generation‘omics’(metagenomics,transcriptomics,proteomics,and metabolomics)technologies made it possible to precisely identify microbiota and metabolites and describe their variability between individuals,populations and even different time points within the same subjects.With massive efforts made,it is now generally accepted that the gut microbiota is a dynamically changing population,whose composition is influenced by the hosts’health conditions and lifestyles.Diet is one of the major contributors to shaping the gut microbiota.The components in the diets vary in different countries,religions,and populations.Some special diets have been adopted by people for hundreds of years aiming for better health,while the underlying mechanisms remain largely unknown.Recent studies based on volunteers or diet-treated animals demonstrated that diets can greatly and rapidly change the gut microbiota.The unique pattern of the nutrients from the diets and their metabolites produced by the gut microbiota has been linked with the occurrence of diseases,including obesity,diabetes,nonalcoholic fatty liver disease,cardiovascular disease,neural diseases,and more.This review will summarize the recent progress and current understanding of the effects of different dietary patterns on the composition of gut microbiota,bacterial metabolites,and their effects on the host's metabolism.展开更多
Plant root hairs are essential for mineral and water absorption,which possess sophisticated sensory mechanisms to allow them to respond to different environmental signals.Ammonium(NH^(+))is a major form of nitrogen in...Plant root hairs are essential for mineral and water absorption,which possess sophisticated sensory mechanisms to allow them to respond to different environmental signals.Ammonium(NH^(+))is a major form of nitrogen in the soil.NH^(+)can influence the root system architecture,such as root hair growth(Liu and von Wir en,2017).展开更多
文摘We review the themes relating to the proposition that“quantization commutes with reduction”([Q,R]=0),from symplectic manifolds to Cauchy-Riemann manifolds.
基金financially supported by the National Natural Science Foundation of China(Nos.22275068 and 21975178)the Fundamental Research Funds for the Central Universitiesthe Open Project of the State Key Laboratory of Supramolecular Structure and Materials.
文摘Mechanochromophores based on bichromic molecular switches,such as bis-naphthopyanes,allow multimodal mechanochromic behavior beyond the typical binary response from single chromophores,which is important for distinguishing between multiple stress states through discrete changes in color.Spontaneously generated persistent and distinguishable multi-colors from activated bis-naphthopyanes remain challenging.And the versatility of bis-mechanophore design for advanced optical molecular systems and the fundamental insights into the corresponding mechano-reactivity are not enough.Here,we identify a dihydroanthracene bridged bis-naphthopyrans as a multimodal mechanochromophore in polymers.Bridging two pyrans with the sterically constrained dihydroanthracene is helpful to control the steric effect for the favorable formation of a distinctly appreciable bis-merocyanine(bis-MC)product.By varying the length of the polymer chains,the force delivered to the mechanophore is modulated,resulting in a gradient change in the relative distribution of two distinctly colored MC products and a multicolor mechanochromism.Mechanical activation of this bis-naphthopyanes proceeds via a mechanistically distinct pathway compared to the photochemical process.In addition,the bulk films can also achieve pronounced color changes when subjected to mechanical force.This study thus further expands the molecular diversity of mechanochromophores and tune the multimodal switch properties of bis-naphthopyrans based polymers.
基金The authors thank Xingen Liu,Minglang Hu,Wei Wu,and Yue-Wen Fang for stimulating discussions.This work was supported by the Tokyo Tech World Research Hub Initiative(WRHI)Program of the Institute of Innovative Research,Tokyo Institute of Technology,the National Natural Science Foundation of China(Grants No.51861145315,No.11929401,No.12074241,No.52130204)the Science and Technology Commission of Shanghai Municipality(Grant No.19010500500,No.20501130600,No.19DZ2270200)+2 种基金the Independent Research and Development Project of State Key Laboratory of Advanced Special Steel,Shanghai Key Laboratory of Advanced Ferro Metallurgy,Shanghai University(Grant No.SKLASS 2020-Z07)Austrian Research Promotion Agency(FFG,Grant No.870024,project acronym MagnifiSens)High-Performance Computing Center,Shanghai University。
文摘Vertical ferroelectricity where a net dipole moment appears as a result of in-plane ionic displacements has gained enormous attention following its discovery in transition metal dichalcogenides.Based on first-principles calculations,we report on the evidence of robust vertical ferroelectricity upon interlayer sliding in layered semiconductingβ-ZrI_(2),a sister material of polar semimetals MoTe_(2)and WTe_(2).The microscopic origin of ferroelectricity in ZrI_(2)is attributed to asymmetric shifts of electronic charges within a trilayer,revealing a subtle interplay of rigid sliding displacements and charge redistribution down to ultrathin thicknesses.We further investigate the variety of ferroelectric domain boundaries and predict a stable charged domain wall with a quasi-twodimensional electron gas and a high built-in electric field that can increase electron mobility and electromechanical response in multifunctional devices.Semiconducting behaviour and a small switching barrier of ZrI_(2)hold promise for various ferroelectric applications,and our results provide important insights for further development of slidetronics ferroelectricity.
基金X.Ma partially supported by Institut Universitaire de France.G.Marinescu partially supported by DFG funded projects SFB/TR 12 and MA 2469/2-2.
文摘In this short note,we compare our previous work on the off-diagonal expansion of the Bergman kernel and the preprint of Lu-Shiffman(arXiv:1301.2166).In particular,we note that the vanishing of the coefficient of p−1/2 is implicitly contained in Dai-Liu-Ma’s work(J.Differ.Geom.72(1),1-41,2006)and was explicitly stated in our book(Holomorphic Morse inequalities and Bergman kernels.Progress in Math.,vol.254,2007).
基金supported by grants from the National Key R&D Program of China(2019YFA0802300 to S.H.)Training Program of the Major Research Plan of the National Natural Science Foundation of China(91957117)+3 种基金National Natural Science Foundation of China(31971082)Shanghai Pujiang Program(18PJ1400500)Open Research Fund of the National Key Laboratory of Genetic Engineering(SKLGE1805)to S.H.Y.S.was supported by the Halfond-Weil Postdoctoral Fellowship.
文摘The gut microbiota refers to the gross collection of microorganisms,estimated trillions of them,which reside within the gut and play crucial roles in the absorption and digestion of dietary nutrients.In the past decades,the new generation‘omics’(metagenomics,transcriptomics,proteomics,and metabolomics)technologies made it possible to precisely identify microbiota and metabolites and describe their variability between individuals,populations and even different time points within the same subjects.With massive efforts made,it is now generally accepted that the gut microbiota is a dynamically changing population,whose composition is influenced by the hosts’health conditions and lifestyles.Diet is one of the major contributors to shaping the gut microbiota.The components in the diets vary in different countries,religions,and populations.Some special diets have been adopted by people for hundreds of years aiming for better health,while the underlying mechanisms remain largely unknown.Recent studies based on volunteers or diet-treated animals demonstrated that diets can greatly and rapidly change the gut microbiota.The unique pattern of the nutrients from the diets and their metabolites produced by the gut microbiota has been linked with the occurrence of diseases,including obesity,diabetes,nonalcoholic fatty liver disease,cardiovascular disease,neural diseases,and more.This review will summarize the recent progress and current understanding of the effects of different dietary patterns on the composition of gut microbiota,bacterial metabolites,and their effects on the host's metabolism.
基金supported by the National Natural Science Foundation of China (31970198 and 31900239)the Natural Science Foundation of Henan Province (202300410230).
文摘Plant root hairs are essential for mineral and water absorption,which possess sophisticated sensory mechanisms to allow them to respond to different environmental signals.Ammonium(NH^(+))is a major form of nitrogen in the soil.NH^(+)can influence the root system architecture,such as root hair growth(Liu and von Wir en,2017).
