A facile method for decarboxylative amination driven by the photoactivity of electron donor-acceptor(EDA)com-plexes assembled from iodide salts and redox-active esters has been proposed.A broad array of acyclic and cy...A facile method for decarboxylative amination driven by the photoactivity of electron donor-acceptor(EDA)com-plexes assembled from iodide salts and redox-active esters has been proposed.A broad array of acyclic and cyclic protected amines were readily synthesized without requiring exogenous transition-metal or photoredox catalysts.Moreover,this ap-proach facilitates late-stage functionalization of complex molecules and is amenable to continuous-flow process on gram scale.展开更多
The transition metal-free chalcogen trifluoromethylation of alkenes represents a highly efficient transformation for the rapid generation of C(sp3)-rich aliphatic trifluoromethyl compounds. However, a unified methodol...The transition metal-free chalcogen trifluoromethylation of alkenes represents a highly efficient transformation for the rapid generation of C(sp3)-rich aliphatic trifluoromethyl compounds. However, a unified methodology to achieve oxy-, thio-, and seleno-trifluoromethylation remains elusive yet highly desirable. In this study, we report a triarylamine-catalyzed three-component vicinal chalcogen-trifluoromethylation of alkenes under blue light irradiation without the need of transition metal catalyst. This reaction is broadly applicable to oxy, thio, and seleno nucleophiles, facilitating modular access to a diverse array of β-trifluoromethyl alcohols, ethers, thioethers, thiocyanates, and selenocyanates with good yields and predictable regioselectivities (61 examples). Additionally, we demonstrate its application in the late-stage modification of natural products and pharmaceutical compounds. Preliminary mechanistic studies suggest that a catalytic electron donor-acceptor (EDA) complex between triarylamine and the Umemoto reagent is key to enabling the radical/polar crossover process.展开更多
Herein,we present a versatile,metal-free protocol for arene C-H functionalization through arylsulfonium salts.A key discovery is that simple halogen anions(iodine,bromine)can act as electron donors when combined with ...Herein,we present a versatile,metal-free protocol for arene C-H functionalization through arylsulfonium salts.A key discovery is that simple halogen anions(iodine,bromine)can act as electron donors when combined with arylsulfonium salts,forming electron donor-acceptor complexes that generate aryl radicals upon visible light irradiation.This method enables the late-stage modification of complex bioactive and pharmaceutical compounds,facilitating arene iodination,bromination,phosphonylation,and arylation,which are challenging to achieve with comparable selectivity,diversity,and practicality using other approaches.Notably,the one-pot protocol for arene C-H iodination and C(sp^(2))-C(sp^(3))bond formation,along with successful gram-scale iodination and phosphonylation of boscalid,highlights the scalability and practical utility of this strategy.展开更多
The formation and the presence of hypervalent Si in the electron donor-acceptor com- plex H_3N·SiH_3 Cl have been investigated by ab initio calculation. The results show that there is a 0.707eV decrease of energy...The formation and the presence of hypervalent Si in the electron donor-acceptor com- plex H_3N·SiH_3 Cl have been investigated by ab initio calculation. The results show that there is a 0.707eV decrease of energy when the complex H_3N.SiH_3 Cl is formed from NH_3 and H_3SiCl, the interaction potential between the donor NH_3 and the acceptor H_3SiCl belongs to the Morse type, and the bond angle A(H-Si-Cl) versus bond length d(N-Si) presents a linear relation. The results also show that the interaction is mainly from giving the lone pair electrons in HOMO of NH_3 to LUMO of H_3SiCl, in which the 2P_z of N and the 3d_0 of Si play important role. Bond N-Si is a weak n-σ*type dative one.展开更多
Photochromic materials attract significant attention for their applications in anticounterfeiting devices,optical switches and molecular sensors.However,the influence of solvent molecules,particularly coordinated solv...Photochromic materials attract significant attention for their applications in anticounterfeiting devices,optical switches and molecular sensors.However,the influence of solvent molecules,particularly coordinated solvents,on electron transfer(ET)photochromic systems remains poorly understood.In this study,we synthesized a series of isostructural metal-organic complexes(MOCs),[Mn(ADC)(L)]n(ADC=9,10-anthracenedicarboxylic acid,L=DMF for 1,DMA for 2,MEA for 3,and DMSO for 4)to investigate the solvent-chromic behavior.All these MOCs exhibit typical radical-induced chromism upon illumination with a xenon lamp at room temperature.It is worth noting that coordination solvent molecules significantly modulate the photochromic response rate.Among the compounds studied,compound 1 exhibits the fastest response,while compound 3 shows the slowest.This variation in rate correlates with differences in the optimal ET path length within their structures.Specifically,solvent molecules regulate the C-H…π interaction distance through their steric hindrance and electronic prop-erties.Shorter C-H…π paths facilitate more efficient ET upon photoexcitation,thus leading to faster photo-chromic response rates.Furthermore,illumination actuates magnetic couplings between photogenerated radicals and Mn^(2+)centers,resulting in a significant increase in room-temperature magnetization,demonstrating a photomagnetic response.This study demonstrates that coordinating solvent selection effectively controls photoinduced ET behavior,providing new insights for designing advanced photoactive materials.展开更多
A new catalytic decarboxylative cyanation and thiocyanation via a synergistic Na I/Cu catalysis is developed.The photoexcited electron donor-acceptor complex by assembly of Na I,R3P,and N-acyloxy-phthalimide ester(NHP...A new catalytic decarboxylative cyanation and thiocyanation via a synergistic Na I/Cu catalysis is developed.The photoexcited electron donor-acceptor complex by assembly of Na I,R3P,and N-acyloxy-phthalimide ester(NHPI ester)triggers the generation of alkyl radical species,which then engages in Cu-catalyzed radical coupling process.Key to success of this dual catalytic transformation is the reliable charge transfer between I·and Cu(I).This dual catalytic platform can eliminate the use of expensive iridium-based photocatalyst or synthetically elaborate organic dyes.A series of primary,secondary,and tertiary alkyl nitriles and thiocyanates are easily synthesized.Moreover,an asymmetric decarboxylative cyanation by applying a chiral Cu catalyst is also developed to afford chiral nitriles in high enantioselectivity.The mechanistic details and the origin of the high enantioselectivity are further investigated by the mechanistic experiments and the density functional theory calculations.展开更多
Understanding the complex plasma dynamics in ultra-intense relativistic laser-solid interactions is of fundamental importance for applications of laser-plasma-based particle accelerators,the creation of high-energy-de...Understanding the complex plasma dynamics in ultra-intense relativistic laser-solid interactions is of fundamental importance for applications of laser-plasma-based particle accelerators,the creation of high-energy-density matter,understanding planetary science,and laser-driven fusion energy.However,experimental efforts in this regime have been limited by the lack of accessibility of over-critical densities and the poor spatiotemporal resolution of conventional diagnostics.Over the last decade,the advent of femtosecond brilliant hard X-ray free-electron lasers(XFELs)has opened new horizons to overcome these limitations.Here,for the first time,we present full-scale spatiotemporal measurements of solid-density plasma dynamics,including preplasma generation with tens of nanometer scale length driven by the leading edge of a relativistic laser pulse,ultrafast heating and ionization at the main pulse arrival,the laser-driven blast wave,and transient surface return current-induced compression dynamics up to hundreds of picoseconds after interaction.These observations are enabled by utilizing a novel combination of advanced X-ray diagnostics including small-angle X-ray scattering,resonant X-ray emission spectroscopy,and propagation-based X-ray phase-contrast imaging simultaneously at the European XFEL-HED beamline station.展开更多
A lipid_depleted cytochrome b 6f (Cyt b 6f) preparation was obtained from spinach (Spinacia oleracea L.) chloroplasts. Upon reconstitution of this preparation with the membrane lipids purified from spinach thylakoid...A lipid_depleted cytochrome b 6f (Cyt b 6f) preparation was obtained from spinach (Spinacia oleracea L.) chloroplasts. Upon reconstitution of this preparation with the membrane lipids purified from spinach thylakoid, the effects of different membrane lipids on the electron transfer activity were studied. The results show that the electron transfer activity of Cyt b 6f is obviously stimulated to different extents, respectively, by monogalactosyldiacylglycerol (MGDG), digalactosyldiacylglycerol (DGDG), phosphatidylcholine (PC), phosphatidylglycerol (PG) and sulfoquinovosyldiacylglycerol (SQDG), and that the extents of stimulation may be closely related to the charge of the membrane lipids. The stimulation of non_charged lipids (MGDG, DGDG) and neutrally_charged lipid (PC) was high with a maximum enhancement of 89%, 75% and 77%, respectively; but the stimulation of two kinds of negatively_charged lipid (PG and SQDG) was relatively low with a maximum enhancement of 43% and 26%, respectively.展开更多
Large,3D curved electronics are a trend of the microelectronic industry due to their unique ability to conformally coexist with complex surfaces while retaining the electronic functions of 2D planar integrated circuit...Large,3D curved electronics are a trend of the microelectronic industry due to their unique ability to conformally coexist with complex surfaces while retaining the electronic functions of 2D planar integrated circuit technologies.However,these curved electronics present great challenges to the fabrication processes.Here,we propose a reconfigurable,mask-free,conformal fabrication strategy with a robot-like system,called robotized‘transfer-and-jet’printing,to assemble diverse electronic devices on complex surfaces.This novel method is a ground-breaking advance with the unique capability to integrate rigid chips,flexible electronics,and conformal circuits on complex surfaces.Critically,each process,including transfer printing,inkjet printing,and plasma treating,are mask-free,digitalized,and programmable.The robotization techniques,including measurement,surface reconstruction and localization,and path programming,break through the fundamental constraints of 2D planar microfabrication in the context of geometric shape and size.The transfer printing begins with the laser lift-off of rigid chips or flexible electronics from donor substrates,which are then transferred onto a curved surface via a dexterous robotic palm.Then the robotic electrohydrodynamic printing directly writes submicrometer structures on the curved surface.Their permutation and combination allow versatile conformal microfabrication.Finally,robotized hybrid printing is utilized to successfully fabricate a conformal heater and antenna on a spherical surface and a flexible smart sensing skin on a winged model,where the curved circuit,flexible capacitive and piezoelectric sensor arrays,and rigid digital–analog conversion chips are assembled.Robotized hybrid printing is an innovative printing technology,enabling additive,noncontact and digital microfabrication for 3D curved electronics.展开更多
The relationship between the electronic structures of manganese nitrido complexes and the substituted ligands is investigated by using density functional theory.By designing a series of manganese nitrido complexes [Mn...The relationship between the electronic structures of manganese nitrido complexes and the substituted ligands is investigated by using density functional theory.By designing a series of manganese nitrido complexes [Mn（SalenR）N]＋ with different para ring substituents（R = H,CH_3,NH_2,OCH_3,NMeF,etc） of the ancillary ligand,the properties of manganese-nitrogen bonds were compared for two kinds of electronic structures,of which the radical resides on metal center or the coordinated ring ligand.Our calculation shows that for R = H,CH_3 and NH_2,the [Mn（SalenR）N]＋ complexes have a high-valent Mn（VI） center,and for R = OCH_3 and NMeF,the complexes represent a configuration where the radical delocalizes on the ligand.It is found that the relative energies of these two species depend on electronic properties of the substituent,originating from the intrinsic property of HOMO-LUMO gaps.展开更多
Electron paramagnetic resonance(EPR)or electron spin resonance(ESR)has been widely employed to characterize transition metal complexes.However,because of the high degree of complexity of transition metal EPR spectra,h...Electron paramagnetic resonance(EPR)or electron spin resonance(ESR)has been widely employed to characterize transition metal complexes.However,because of the high degree of complexity of transition metal EPR spectra,how to extract the underlying electronicstructure information inevitably poses a major challenge to beginners,in particular for systems with S>1/2.In fact,the physical principles of transition metal EPR have long been well-established and since 1970s a series of dedicated voluminous monographs have been published already.Not surprisingly,they are not appropriate stating points for novices to grasp a panorama of the profound theory prior to scrutinizing in-depth references.The present review aims to fill this gap to provide a perspective of transition metal EPR and unveil some peculiar subtleties thereof on the basis of our recent work.展开更多
Studies on the electronic structure,molecular design,syntheses of some novel series of tetranuclear rare earth complexes in our laboratory have been reviewed.Spin-unrestricted localized INDO method was used to calcula...Studies on the electronic structure,molecular design,syntheses of some novel series of tetranuclear rare earth complexes in our laboratory have been reviewed.Spin-unrestricted localized INDO method was used to calculate the electronic structure and the chemical bonding in the typical rare earth cluster Sc[Sc_6Cl_(12)Co]was discussed.展开更多
This paper investigates the infrared absorption spectra of oxygen-related complexes in silicon crystals irradiated with electron （1.5 MeV） at 360 K.Two groups of samples with low [Oi] = 6.9 x 10^17 cm^-3 and high [O...This paper investigates the infrared absorption spectra of oxygen-related complexes in silicon crystals irradiated with electron （1.5 MeV） at 360 K.Two groups of samples with low [Oi] = 6.9 x 10^17 cm^-3 and high [Oi] = 1.06 x 10^18 cm^-3 were used.We found that the concentration of the VO pairs have different behaviour to the annealing temperature in different concentration of oxygen specimen,it is hardly changed in the higher concentration of oxygen specimen.It was also found that the concentration of VO2 in lower concentration of oxygen specimen gets to maximum at 450 ℃ and then dissapears at 500 ℃,accompanied with the appearing of VO3. For both kinds of specimens,the concentration of VO3 reachs to maximum at 550 ℃ and does not disappear completely at 600 ℃.展开更多
The nonrelativistic DV-X_α-SCC method was used to study the electronic structure and chemi- cal bonding of tetranuclear neodymium complex Nd_4O(OR)_4(NR′_2)_6,with emphasis on the bonding charac- ter of the central ...The nonrelativistic DV-X_α-SCC method was used to study the electronic structure and chemi- cal bonding of tetranuclear neodymium complex Nd_4O(OR)_4(NR′_2)_6,with emphasis on the bonding charac- ter of the central μ_4-O atom and the four Nd atoms.The results of calculation show that the μ_4-O atom uses its sp^3 valence orbitals to contribute four O-Nd bonding MOs with character of multicenter bond apparent- ly.The Mulliken population analysis shows that the overlap population between Nd atoms is almost equal to zero,therefore there is no direct metal-metal bond between Nd atoms.The coordination number of Nd in the complex is discussed briefly.展开更多
Molybenum＇s effects when added in the γ phase of nickel-based superalloys were studied using the lattice Green＇s function multiscale method. The electronic structure of the dislocation-Mo complex was analyzed and h...Molybenum＇s effects when added in the γ phase of nickel-based superalloys were studied using the lattice Green＇s function multiscale method. The electronic structure of the dislocation-Mo complex was analyzed and hybridization was found to contribute to the strengthening. Moreover, by combining the interaction energies calculated from two scales, the yield stress was theoretically predicted at 0 K and finite temperature.展开更多
The electronic structure and electronic absorption spectra of binuclear Au(Ⅰ) complexes with bidentate phophines and a bidentate ylid ligand have been studied using quasirelativistic pseudopotential ab initio cal...The electronic structure and electronic absorption spectra of binuclear Au(Ⅰ) complexes with bidentate phophines and a bidentate ylid ligand have been studied using quasirelativistic pseudopotential ab initio calculations at the HF and MP2 levels by the LANL2DZ basis sets. The electronic properties of the spectral transition and Au(Ⅰ)—Au(Ⅰ) interaction were also discussed.展开更多
The electronic structures of several dinuclears and trinuclears of molybdenum containing thiolates complexes have been calculated by quantum chemistry SCC-DV-Xa method, and the reactivity of complexes has been analy...The electronic structures of several dinuclears and trinuclears of molybdenum containing thiolates complexes have been calculated by quantum chemistry SCC-DV-Xa method, and the reactivity of complexes has been analyzed in terms of the molecular orbital energy level diagrams, orbital characters and charge populations.展开更多
Cylindrical and spherical dust-electron-acoustic （DEA） shock waves and double layers in an unmagnetized, col- lisionless, complex or dusty plasma system are carried out. The plasma system is assumed to be composed o...Cylindrical and spherical dust-electron-acoustic （DEA） shock waves and double layers in an unmagnetized, col- lisionless, complex or dusty plasma system are carried out. The plasma system is assumed to be composed of inertial and viscous cold electron fluids, nonextensive distributed hot electrons, Maxwellian ions, and negatively charged stationary dust grains. The standard reductive perturbation technique is used to derive the nonlinear dynamical equations, that is, the nonplanar Burgers equation and the nonplanar further Burgers equation. They are also numerically analyzed to investigate the basic features of shock waves and double layers （DLs）. It is observed that the roles of the viscous cold electron fluids, nonextensivity of hot electrons, and other plasma parameters in this investigation have significantly modified the basic features （such as, polarity, amplitude and width） of the nonplanar DEA shock waves and DLs. It is also observed that the strength of the shock is maximal for the spherical geometry, intermediate for cylindrical geometry, while it is minimal for the planar geometry. The findings of our results obtained from this theoretical investigation may be useful in understanding the nonlinear phenomena associated with the nonplanar DEA waves in both space and laboratory plasmas.展开更多
The electronic structure and chemical bonding of[Ce(CO_3)_3O_2]_2^(8-) have been studied by INDO (Intermediate Neglect of Differentiated Overlap)method in this paper.The results obtained show that the HOMO of[Ce(CO_3)...The electronic structure and chemical bonding of[Ce(CO_3)_3O_2]_2^(8-) have been studied by INDO (Intermediate Neglect of Differentiated Overlap)method in this paper.The results obtained show that the HOMO of[Ce(CO_3)_3O_2]_2^(8-) is mainly composed of the anti-bonding π orbitals of the pcroxide ion(O_2^(2-)) and the LUMO is mainly composed of the 4f orbitals of the Ce(Ⅳ).The peroxide ion coordinates to ceric ion by means of σ and π dative bonds.After coordination the O-O bond of the peroxide ions is strengthened.By comparison with cerous complexes,the contribution of the 4f orbitals to bonding increases in the ceric com- plex.展开更多
文摘A facile method for decarboxylative amination driven by the photoactivity of electron donor-acceptor(EDA)com-plexes assembled from iodide salts and redox-active esters has been proposed.A broad array of acyclic and cyclic protected amines were readily synthesized without requiring exogenous transition-metal or photoredox catalysts.Moreover,this ap-proach facilitates late-stage functionalization of complex molecules and is amenable to continuous-flow process on gram scale.
基金the financial support provided by the National Natural Science Foundation of China(22361142832,92156025,22271212)the Science and Technology Project of Hebei Education Department Foundation(BJ2025192)We would like to thank Dr.Guosheng Ding,Dr.Kongying Zhu,and Dr.Xiaojuan Deng at the Analysis and Testing Center of Tianjin University for their assistance with NMR testing and analysis.
文摘The transition metal-free chalcogen trifluoromethylation of alkenes represents a highly efficient transformation for the rapid generation of C(sp3)-rich aliphatic trifluoromethyl compounds. However, a unified methodology to achieve oxy-, thio-, and seleno-trifluoromethylation remains elusive yet highly desirable. In this study, we report a triarylamine-catalyzed three-component vicinal chalcogen-trifluoromethylation of alkenes under blue light irradiation without the need of transition metal catalyst. This reaction is broadly applicable to oxy, thio, and seleno nucleophiles, facilitating modular access to a diverse array of β-trifluoromethyl alcohols, ethers, thioethers, thiocyanates, and selenocyanates with good yields and predictable regioselectivities (61 examples). Additionally, we demonstrate its application in the late-stage modification of natural products and pharmaceutical compounds. Preliminary mechanistic studies suggest that a catalytic electron donor-acceptor (EDA) complex between triarylamine and the Umemoto reagent is key to enabling the radical/polar crossover process.
基金supported by the National Natural Science Foundation of China(22101272)the National Youth Talent Programthe Research Start-Up Funds of Hefei University of Technology。
文摘Herein,we present a versatile,metal-free protocol for arene C-H functionalization through arylsulfonium salts.A key discovery is that simple halogen anions(iodine,bromine)can act as electron donors when combined with arylsulfonium salts,forming electron donor-acceptor complexes that generate aryl radicals upon visible light irradiation.This method enables the late-stage modification of complex bioactive and pharmaceutical compounds,facilitating arene iodination,bromination,phosphonylation,and arylation,which are challenging to achieve with comparable selectivity,diversity,and practicality using other approaches.Notably,the one-pot protocol for arene C-H iodination and C(sp^(2))-C(sp^(3))bond formation,along with successful gram-scale iodination and phosphonylation of boscalid,highlights the scalability and practical utility of this strategy.
文摘The formation and the presence of hypervalent Si in the electron donor-acceptor com- plex H_3N·SiH_3 Cl have been investigated by ab initio calculation. The results show that there is a 0.707eV decrease of energy when the complex H_3N.SiH_3 Cl is formed from NH_3 and H_3SiCl, the interaction potential between the donor NH_3 and the acceptor H_3SiCl belongs to the Morse type, and the bond angle A(H-Si-Cl) versus bond length d(N-Si) presents a linear relation. The results also show that the interaction is mainly from giving the lone pair electrons in HOMO of NH_3 to LUMO of H_3SiCl, in which the 2P_z of N and the 3d_0 of Si play important role. Bond N-Si is a weak n-σ*type dative one.
基金supported by the National Natural Science Foundation of China(22171155,22571174)Natural Science Foundation of Shandong Province(ZR2022YQ07)+1 种基金Taishan Scholar Program(tsqn202306166)the State Key Laboratory of Fine Chemicals,Dalian University of Technology(KF 2409).
文摘Photochromic materials attract significant attention for their applications in anticounterfeiting devices,optical switches and molecular sensors.However,the influence of solvent molecules,particularly coordinated solvents,on electron transfer(ET)photochromic systems remains poorly understood.In this study,we synthesized a series of isostructural metal-organic complexes(MOCs),[Mn(ADC)(L)]n(ADC=9,10-anthracenedicarboxylic acid,L=DMF for 1,DMA for 2,MEA for 3,and DMSO for 4)to investigate the solvent-chromic behavior.All these MOCs exhibit typical radical-induced chromism upon illumination with a xenon lamp at room temperature.It is worth noting that coordination solvent molecules significantly modulate the photochromic response rate.Among the compounds studied,compound 1 exhibits the fastest response,while compound 3 shows the slowest.This variation in rate correlates with differences in the optimal ET path length within their structures.Specifically,solvent molecules regulate the C-H…π interaction distance through their steric hindrance and electronic prop-erties.Shorter C-H…π paths facilitate more efficient ET upon photoexcitation,thus leading to faster photo-chromic response rates.Furthermore,illumination actuates magnetic couplings between photogenerated radicals and Mn^(2+)centers,resulting in a significant increase in room-temperature magnetization,demonstrating a photomagnetic response.This study demonstrates that coordinating solvent selection effectively controls photoinduced ET behavior,providing new insights for designing advanced photoactive materials.
基金supported by the National Natural Science Foundation of China(22201087)the National Key R&D Program of China(2022YFA1503200)Guangdong Basic and Applied Basic Research Foundation(2022A1515012507)。
文摘A new catalytic decarboxylative cyanation and thiocyanation via a synergistic Na I/Cu catalysis is developed.The photoexcited electron donor-acceptor complex by assembly of Na I,R3P,and N-acyloxy-phthalimide ester(NHPI ester)triggers the generation of alkyl radical species,which then engages in Cu-catalyzed radical coupling process.Key to success of this dual catalytic transformation is the reliable charge transfer between I·and Cu(I).This dual catalytic platform can eliminate the use of expensive iridium-based photocatalyst or synthetically elaborate organic dyes.A series of primary,secondary,and tertiary alkyl nitriles and thiocyanates are easily synthesized.Moreover,an asymmetric decarboxylative cyanation by applying a chiral Cu catalyst is also developed to afford chiral nitriles in high enantioselectivity.The mechanistic details and the origin of the high enantioselectivity are further investigated by the mechanistic experiments and the density functional theory calculations.
基金funding from Grant No. HIDSS-0002 DASHH (Data Science in Hamburg-Helmholtz Graduate School for the Structure of Matter)partially supported by the Helmholtz Imaging platform through the project “Smart Phase.”
文摘Understanding the complex plasma dynamics in ultra-intense relativistic laser-solid interactions is of fundamental importance for applications of laser-plasma-based particle accelerators,the creation of high-energy-density matter,understanding planetary science,and laser-driven fusion energy.However,experimental efforts in this regime have been limited by the lack of accessibility of over-critical densities and the poor spatiotemporal resolution of conventional diagnostics.Over the last decade,the advent of femtosecond brilliant hard X-ray free-electron lasers(XFELs)has opened new horizons to overcome these limitations.Here,for the first time,we present full-scale spatiotemporal measurements of solid-density plasma dynamics,including preplasma generation with tens of nanometer scale length driven by the leading edge of a relativistic laser pulse,ultrafast heating and ionization at the main pulse arrival,the laser-driven blast wave,and transient surface return current-induced compression dynamics up to hundreds of picoseconds after interaction.These observations are enabled by utilizing a novel combination of advanced X-ray diagnostics including small-angle X-ray scattering,resonant X-ray emission spectroscopy,and propagation-based X-ray phase-contrast imaging simultaneously at the European XFEL-HED beamline station.
基金The State Key Basic Research and Development Plan(G1998010100)Innovative Foundation of Laboratory of Photosynthesis Basic Research Insitute of Botany,The Chinese Academy of Sciences
文摘A lipid_depleted cytochrome b 6f (Cyt b 6f) preparation was obtained from spinach (Spinacia oleracea L.) chloroplasts. Upon reconstitution of this preparation with the membrane lipids purified from spinach thylakoid, the effects of different membrane lipids on the electron transfer activity were studied. The results show that the electron transfer activity of Cyt b 6f is obviously stimulated to different extents, respectively, by monogalactosyldiacylglycerol (MGDG), digalactosyldiacylglycerol (DGDG), phosphatidylcholine (PC), phosphatidylglycerol (PG) and sulfoquinovosyldiacylglycerol (SQDG), and that the extents of stimulation may be closely related to the charge of the membrane lipids. The stimulation of non_charged lipids (MGDG, DGDG) and neutrally_charged lipid (PC) was high with a maximum enhancement of 89%, 75% and 77%, respectively; but the stimulation of two kinds of negatively_charged lipid (PG and SQDG) was relatively low with a maximum enhancement of 43% and 26%, respectively.
基金The authors acknowledge support from the National Nat-ural Science Foundation of China(51635007,51925503,51705179)Natural Science Foundation of Hubei Province of China(2020CFA028).
文摘Large,3D curved electronics are a trend of the microelectronic industry due to their unique ability to conformally coexist with complex surfaces while retaining the electronic functions of 2D planar integrated circuit technologies.However,these curved electronics present great challenges to the fabrication processes.Here,we propose a reconfigurable,mask-free,conformal fabrication strategy with a robot-like system,called robotized‘transfer-and-jet’printing,to assemble diverse electronic devices on complex surfaces.This novel method is a ground-breaking advance with the unique capability to integrate rigid chips,flexible electronics,and conformal circuits on complex surfaces.Critically,each process,including transfer printing,inkjet printing,and plasma treating,are mask-free,digitalized,and programmable.The robotization techniques,including measurement,surface reconstruction and localization,and path programming,break through the fundamental constraints of 2D planar microfabrication in the context of geometric shape and size.The transfer printing begins with the laser lift-off of rigid chips or flexible electronics from donor substrates,which are then transferred onto a curved surface via a dexterous robotic palm.Then the robotic electrohydrodynamic printing directly writes submicrometer structures on the curved surface.Their permutation and combination allow versatile conformal microfabrication.Finally,robotized hybrid printing is utilized to successfully fabricate a conformal heater and antenna on a spherical surface and a flexible smart sensing skin on a winged model,where the curved circuit,flexible capacitive and piezoelectric sensor arrays,and rigid digital–analog conversion chips are assembled.Robotized hybrid printing is an innovative printing technology,enabling additive,noncontact and digital microfabrication for 3D curved electronics.
基金supported by the Project of National Natural Science Foundation of China(No.21573237,21603227,21403242,21703246)Natural Science Foundation of Fujian Province(2017J05032)
文摘The relationship between the electronic structures of manganese nitrido complexes and the substituted ligands is investigated by using density functional theory.By designing a series of manganese nitrido complexes [Mn（SalenR）N]＋ with different para ring substituents（R = H,CH_3,NH_2,OCH_3,NMeF,etc） of the ancillary ligand,the properties of manganese-nitrogen bonds were compared for two kinds of electronic structures,of which the radical resides on metal center or the coordinated ring ligand.Our calculation shows that for R = H,CH_3 and NH_2,the [Mn（SalenR）N]＋ complexes have a high-valent Mn（VI） center,and for R = OCH_3 and NMeF,the complexes represent a configuration where the radical delocalizes on the ligand.It is found that the relative energies of these two species depend on electronic properties of the substituent,originating from the intrinsic property of HOMO-LUMO gaps.
基金the financial support from Chinese Academy of Sciences,National Science Foundation of China(92161204)Max-Planck Society。
文摘Electron paramagnetic resonance(EPR)or electron spin resonance(ESR)has been widely employed to characterize transition metal complexes.However,because of the high degree of complexity of transition metal EPR spectra,how to extract the underlying electronicstructure information inevitably poses a major challenge to beginners,in particular for systems with S>1/2.In fact,the physical principles of transition metal EPR have long been well-established and since 1970s a series of dedicated voluminous monographs have been published already.Not surprisingly,they are not appropriate stating points for novices to grasp a panorama of the profound theory prior to scrutinizing in-depth references.The present review aims to fill this gap to provide a perspective of transition metal EPR and unveil some peculiar subtleties thereof on the basis of our recent work.
基金Project supported by The National Natural Science Foundation of China and Science and Technology Foundation of State Education Commision of China
文摘Studies on the electronic structure,molecular design,syntheses of some novel series of tetranuclear rare earth complexes in our laboratory have been reviewed.Spin-unrestricted localized INDO method was used to calculate the electronic structure and the chemical bonding in the typical rare earth cluster Sc[Sc_6Cl_(12)Co]was discussed.
基金Project supported by the National Natural Science Foundation of China (Grant No 50872028)Natural Science Foundation of Hebei Province of China (Grant Nos E200500048 and E2008000079)Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No 20050080006)
文摘This paper investigates the infrared absorption spectra of oxygen-related complexes in silicon crystals irradiated with electron （1.5 MeV） at 360 K.Two groups of samples with low [Oi] = 6.9 x 10^17 cm^-3 and high [Oi] = 1.06 x 10^18 cm^-3 were used.We found that the concentration of the VO pairs have different behaviour to the annealing temperature in different concentration of oxygen specimen,it is hardly changed in the higher concentration of oxygen specimen.It was also found that the concentration of VO2 in lower concentration of oxygen specimen gets to maximum at 450 ℃ and then dissapears at 500 ℃,accompanied with the appearing of VO3. For both kinds of specimens,the concentration of VO3 reachs to maximum at 550 ℃ and does not disappear completely at 600 ℃.
基金The project supported by the National Natural Science Foundation of China
文摘The nonrelativistic DV-X_α-SCC method was used to study the electronic structure and chemi- cal bonding of tetranuclear neodymium complex Nd_4O(OR)_4(NR′_2)_6,with emphasis on the bonding charac- ter of the central μ_4-O atom and the four Nd atoms.The results of calculation show that the μ_4-O atom uses its sp^3 valence orbitals to contribute four O-Nd bonding MOs with character of multicenter bond apparent- ly.The Mulliken population analysis shows that the overlap population between Nd atoms is almost equal to zero,therefore there is no direct metal-metal bond between Nd atoms.The coordination number of Nd in the complex is discussed briefly.
基金Project supported by Beijing Municipality Science&Technology Commission,China(Grant No.D161100002416001)
文摘Molybenum＇s effects when added in the γ phase of nickel-based superalloys were studied using the lattice Green＇s function multiscale method. The electronic structure of the dislocation-Mo complex was analyzed and hybridization was found to contribute to the strengthening. Moreover, by combining the interaction energies calculated from two scales, the yield stress was theoretically predicted at 0 K and finite temperature.
文摘The electronic structure and electronic absorption spectra of binuclear Au(Ⅰ) complexes with bidentate phophines and a bidentate ylid ligand have been studied using quasirelativistic pseudopotential ab initio calculations at the HF and MP2 levels by the LANL2DZ basis sets. The electronic properties of the spectral transition and Au(Ⅰ)—Au(Ⅰ) interaction were also discussed.
文摘The electronic structures of several dinuclears and trinuclears of molybdenum containing thiolates complexes have been calculated by quantum chemistry SCC-DV-Xa method, and the reactivity of complexes has been analyzed in terms of the molecular orbital energy level diagrams, orbital characters and charge populations.
文摘Cylindrical and spherical dust-electron-acoustic （DEA） shock waves and double layers in an unmagnetized, col- lisionless, complex or dusty plasma system are carried out. The plasma system is assumed to be composed of inertial and viscous cold electron fluids, nonextensive distributed hot electrons, Maxwellian ions, and negatively charged stationary dust grains. The standard reductive perturbation technique is used to derive the nonlinear dynamical equations, that is, the nonplanar Burgers equation and the nonplanar further Burgers equation. They are also numerically analyzed to investigate the basic features of shock waves and double layers （DLs）. It is observed that the roles of the viscous cold electron fluids, nonextensivity of hot electrons, and other plasma parameters in this investigation have significantly modified the basic features （such as, polarity, amplitude and width） of the nonplanar DEA shock waves and DLs. It is also observed that the strength of the shock is maximal for the spherical geometry, intermediate for cylindrical geometry, while it is minimal for the planar geometry. The findings of our results obtained from this theoretical investigation may be useful in understanding the nonlinear phenomena associated with the nonplanar DEA waves in both space and laboratory plasmas.
文摘The electronic structure and chemical bonding of[Ce(CO_3)_3O_2]_2^(8-) have been studied by INDO (Intermediate Neglect of Differentiated Overlap)method in this paper.The results obtained show that the HOMO of[Ce(CO_3)_3O_2]_2^(8-) is mainly composed of the anti-bonding π orbitals of the pcroxide ion(O_2^(2-)) and the LUMO is mainly composed of the 4f orbitals of the Ce(Ⅳ).The peroxide ion coordinates to ceric ion by means of σ and π dative bonds.After coordination the O-O bond of the peroxide ions is strengthened.By comparison with cerous complexes,the contribution of the 4f orbitals to bonding increases in the ceric com- plex.
