Four water-soluble porous supramolecular organic framework drug delivery systems（sof-DDSs） have been used to adsorb doxorubicin（DOX） in water at physiological pH of 7.4,which is driven exclusively by hydrophobicit...Four water-soluble porous supramolecular organic framework drug delivery systems（sof-DDSs） have been used to adsorb doxorubicin（DOX） in water at physiological pH of 7.4,which is driven exclusively by hydrophobicity.The resulting complexes DOX@SOFs are formed instantaneously upon dissolving the components in water.The drug-adsorbed sof-DDSs can undergo plasm circulation with important maintenance of the drug and overcome the multidrug resistance of human breast MCF-7/Adr cancer cells.DOX is released readily in the cancer cells due to the protonation of its amino group in the acidic medium of cancer cells.In vitro and in vivo experiments reveal that the delivery of SOF-a-d remarkably improve the cytotoxicity of DOX for the MCF-7/Adr cells and tumors,leading to 13-19-fold reduction of the 1C_（50）values as compared with that of DOX.This new sof-DDSs strategy omits the indispensable loading process required by most of reported nano-scaled carriers for neutral hydrophobic chemotherapeutic agents,and thus should be highly valuable for future development of low-cost delivery systems.展开更多
Water-soluble three-dimensional porous supramolecular organic frameworks（SOFs） have been demonstrated as a new generation of homogeneous polycationic platforms for anti-cancer drug delivery.The new SOF drug delivery...Water-soluble three-dimensional porous supramolecular organic frameworks（SOFs） have been demonstrated as a new generation of homogeneous polycationic platforms for anti-cancer drug delivery.The new SOF drug delivery systems（sof-DDSs） can adsorb dianionic pemetrexed（PMX）,a clinically used chemotherapeutic agent instantaneously upon dissolving in water,which is driven by both electrostatic attraction and hydrophobicity.The in situ-prepared PMX@SOFs are highly stable and can avoid important release of the drug during plasm circulation and overcome the multidrug resistance of human breast MCF-7/Adr cancer cells to enter the cancer cells.Acidic microenvironment of cancer cells promotes the release of the drug in cancer cells.Both in vitro and in vivo studies have revealed that sofDDSs considerably improve the treatment efficacy of PMX,leading to 6-12-fold reduction of the IC50 values,as compared with that of PMX alone.The new drug delivery strategy omits the loading process required by most of reported nanoparticle-based delivery systems and thus holds promise for future development of low-cost drug delivery systems展开更多
蛋白质的动态特性和结构活性对于蛋白质功能的调控具有根本意义。传统的结构确定方法(包括X射线和电子显微镜单颗粒分析技术等)往往需要成千上万不同蛋白质分子的平均信号,因此难以确定蛋白质分子的动态结构。而电子显微断层成像技术是...蛋白质的动态特性和结构活性对于蛋白质功能的调控具有根本意义。传统的结构确定方法(包括X射线和电子显微镜单颗粒分析技术等)往往需要成千上万不同蛋白质分子的平均信号,因此难以确定蛋白质分子的动态结构。而电子显微断层成像技术是一种对独个生物个体结构从不同的观测角度照相、并计算来恢复该个体的三维结构密度图的方法。传统的冷冻电子断层成像重构方法采用整个大尺寸电镜图像进行重构计算,通常用来研究细菌、细胞切片等大尺寸生物个体在较低分辨率下的结构;由于分辨率的限制,不足以获得小尺寸的蛋白质分子的结构细节。最近,任罡研究小组提出一种独个生物颗粒的电子显微断层成像方法(individual-particle electron tomography,IPET)。该方法通过减小图像尺寸(直至所选区域只包含单个蛋白质分子)的策略,运用提出的FETR(focused electron tomography reconstruction)算法来提高独个大分子重构的分辨率。此方法不需要初始模型和大量分子的平均信号,同时能够容忍一定的测角误差。本文综述了IPET/FETR方法在确定独个分子结构过程中的具体步骤以及如何应用该方法来研究蛋白动态特性和结构变化特征。期望通过该综述和国内同行交流,分享最新的前沿研究,为赶超世界科技前沿的建设添砖加瓦。展开更多
抗体(antibody)又称免疫球蛋白(immunoglobulin,Ig),是人体免疫反应的重要参与者.了解抗体的结构和结构动态特征,是理解人体免疫作用机理、修复或提高免疫能力、定向设计抗体以治疗各种疾病的基础.本文以人体IgG1抗体为对象,综述了使用...抗体(antibody)又称免疫球蛋白(immunoglobulin,Ig),是人体免疫反应的重要参与者.了解抗体的结构和结构动态特征,是理解人体免疫作用机理、修复或提高免疫能力、定向设计抗体以治疗各种疾病的基础.本文以人体IgG1抗体为对象,综述了使用透射电子显微学方法研究IgG1抗体结构方向的最新进展.详细介绍了使用逐个分子的电子断层三维重构技术(individual-particle electron tomography,IPET)对抗体进行结构研究的方法,包括样品制备、图像处理和数据分析等.并描述了利用该技术,在研究抗体结合肽分子后的结构形变和通过收集不同构象来研究抗体动态结构特征方面所取得的阶段性成果.最后,对尚待解决的关键问题与该技术未来的发展方向进行了讨论与展望.展开更多
A catalyst of ferroelectric-BaTiO_(3)@photoelectric-TiO_(2) nanohybrids(BaTiO_(3)@TiO_(2))with enhanced photocatalytic activity was synthesized via a hydrolysis precipitation combined with a hydrothermal approach.Comp...A catalyst of ferroelectric-BaTiO_(3)@photoelectric-TiO_(2) nanohybrids(BaTiO_(3)@TiO_(2))with enhanced photocatalytic activity was synthesized via a hydrolysis precipitation combined with a hydrothermal approach.Compared to pure TiO_(2),pure BaTiO_(3) and BaTiO_(3)/TiO_(2) physical mixture,the heterostructured BaTiO_(3)@TiO_(2) exhibits significantly improved photocatalytic activity and cycling stability in decomposing Rhodamine B(RhB)and the degradation efficiency is 1.7 times higher than pure TiO_(2) and 7.2 times higher than pure BaTiO_(3).These results are mainly attributed to the synergy effect of photoelectric TiO_(2),ferroelectric-BaTiO_(3) and the rationally designed interfacial structure.The mesoporous microstructure of TiO_(2) is of a high specific area and enables excellent photocatalytic activity.The ferroelectric polarization induced built-in electric field in BaTiO_(3) nanoparticles,and the intimate interfacial interactions at the interface of BaTiO_(3) and TiO_(2) are effective in driving the separation and transport of photogenerated charge carriers.This strategy will stimulate the design of heterostructured photocatalysts with outstanding photocatalytic performance via interface engineering.展开更多
The development of polymeric optical materials with a higher refractive index,transparency in the visible spectrum region and easier processability is increasingly desirable for advanced optical applications such as m...The development of polymeric optical materials with a higher refractive index,transparency in the visible spectrum region and easier processability is increasingly desirable for advanced optical applications such as microlenses,image sensors,and organic light-emitting diodes.Most acrylates have a low refractive index(around 1.50)which does not meet the high perfo rmance requirements of advanced optical materials.In this research,three novel acrylates were synthesized via a facile one-step approach and used to fabricate optical transparent polymers.All of the polymers reveal good optical properties including high transparency(≥90%)in the visible spectrum region and high refractive index values(1.6363)at 550 nm.Moreover,nanostructures of these acrylate polymers with various feature sizes including nanogratings and photonic crystals were successfully fabricated using nanoimprint lithography.These results indicate that these acrylates can be used in a wide range of optical and optoelectronic devices where nanopatterned films with high refractive index and transparency are required.展开更多
Challenges facing high-voltage/high-capacity cathodes,in addition to the longstanding problems pertinent to lithium(Li)-metal anodes,should be addressed to develop high-energy-density Li-metal batteries.This issue mos...Challenges facing high-voltage/high-capacity cathodes,in addition to the longstanding problems pertinent to lithium(Li)-metal anodes,should be addressed to develop high-energy-density Li-metal batteries.This issue mostly stems from interfacial instability between electrodes and electrolytes.Conventional carbonate-or ether-based liquid electrolytes suffer from not only volatility and flammability but also limited electrochemical stability window.Here,we report a nitrile electrolyte strategy based on concentrated nitrile electrolytes(CNEs)with co-additives.The CNE consists of high-concentration lithium bis(fluorosulfonyl)imide(LiFSI)in a solvent mixture of succinonitrile(SN)/acetonitrile(AN).The SN/AN solvent mixture is designed to ensure high oxidation stability along with thermal stability,which are prerequisites for high-voltage Li-metal cells.The CNE exhibits interfacial stability with Li metals due to the coordinated solvation structure.Lithium nitrate(LiNO_(3))and indium fluoride(InF_(3))are incorporated in the CNE as synergistic co-additives to further stabilize solid-electrolyte interphase(SEI)on Li metals.The resulting electrolyte(CNE+LiNO_(3)/InF_(3))enables stable cycling performance in Li||LiNi_(0.8)Co_(0.1)Mn_(0.1)and 4.9 V-class Li||LiNi_(0.5)Mn_(1.5)O_(4)cells.Notably,the Li||LiNi_(0.5)Mn_(1.5)O_(4)cell maintains its electrochemical activity at high temperature(100℃)and even in flame without fire or explosion.展开更多
The lithium-sulfur(Li-S)battery is one of the most promising substitutes for current energy storage systems because of its low cost,high theoretical capacity,and high energy density.However,the high solubility of inte...The lithium-sulfur(Li-S)battery is one of the most promising substitutes for current energy storage systems because of its low cost,high theoretical capacity,and high energy density.However,the high solubility of intermediate products(i.e.,lithium polysulfides)and the resultant shuttle effect lead to rapidly fading capacity and a low coulombic efficiency,which hinder the practical application of Li-S batteries.In this study,block copolymers are constructed with both an ethylene oxide unit and a styrene unit and then used as binders for Li-S batteries.Electrochemical performance improvements are attributed to the synergistic effects contributed by the different units of the block copolymer.The ethylene oxide unit traps polysulfide,which bonds strongly with the intermediate lithium polysulfide,and enhances the transport of lithium ions to reach high capacity.Meanwhile,the styrene unit maintains cathode integrity by improving the mechanical properties and elasticity of the constructed block copolymer to accommodate the large volume changes.By enabling multiple functions via different units in the polymer chain,high sulfur utilization is achieved,polysulfide diffusion is confined,and the shuttle effect is suppressed during the cycle life of Li-S batteries,as revealed by operando ultraviolet-visible spectroscopy and S Kedge X-ray absorption spectroscopy.展开更多
Over the past decade,perovskite photovoltaics have approached other currently available technologies and proven to be the most prospective type of solar cells.Although the many-sided research in this very active field...Over the past decade,perovskite photovoltaics have approached other currently available technologies and proven to be the most prospective type of solar cells.Although the many-sided research in this very active field has generated consistent results with regard to their undisputed consistently increasing power conversion efficiency,it also produced several rather contradictory opinions.Among other important details,debate surrounding their proneness to surface degradation and poor mechanical robustness,as well as the environmental footprint of this materials class,remains a moot point.The application of ionic liquids appears as one of the potential remedies to some of these challenges due to their high conductivity,the opportunities for chemical"tuning"of the structure,and relatively lower environmental footprint.This article provides an overview,classification,and applications of ionic liquids in perovskite solar cells.We summarize the use and role of ionic liquids as versatile additives,solvents,and modifiers in perovskite precursor solution,in charge transport layer,and in interfacial and stability engineering.Finally,challenges and the future prospects for the design and/or selection of ionic liquids with a specific profile that meets the requirements for next-generation highly efficient and stable perovskite solar cells are proposed.展开更多
The pre-edges of oxygen-K X-ray absorption spectra have been ubiquitous in transition metal(TM)oxide studies in various fields,especially on the fervent topic of oxygen redox states in battery electrodes.However,criti...The pre-edges of oxygen-K X-ray absorption spectra have been ubiquitous in transition metal(TM)oxide studies in various fields,especially on the fervent topic of oxygen redox states in battery electrodes.However,critical debates remain on the use of the O-K pre-edge variations upon electrochemical cycling as evidences of oxygen redox reactions,which has been a popular practice in the battery field.This study presents an investigation of the O-K pre-edge of 55 oxides covering all 3d TMs with different elements,structures,and electrochemical states through combined experimental and theoretical analyses.It is shown unambiguously that the O-K pre-edge variation in battery cathodes is dominated by changing TM-d states.Furthermore,the pre-edge enables a unique opportunity to project the lowest unoccupied TM-d states onto one common energy window,leading to a summary map of the relative energy positions of the low-lying TM states,with higher TM oxidation states at lower energies,corresponding to higher electrochemical potentials.The results naturally clarify some unusual redox reactions,such as Cr^(3+/6+).This work provides a critical clarification on O-K pre-edge interpretation and more importantly a benchmark database of O-K pre-edge for characterizing redox reactions in batteries and other energy materials.展开更多
The structural model of sodium silicate glass plays a crucial role in understanding the properties and the nature of binary glass and other more complicated silicate glasses.This work proposes a structural model for s...The structural model of sodium silicate glass plays a crucial role in understanding the properties and the nature of binary glass and other more complicated silicate glasses.This work proposes a structural model for sodium silicate glass based on the medium-range ordering structure of silica glass and the information found from the Na_(2)O-SiO_(2) phase diagram.This new model is different from previous ones.First,the sodium silica glass is both structurally and chemically heterogeneous on the nanometer scale.Secondly,the sodium cation distribution is Na_(2)O concentration-dependent.In order to reflect the structural change with Na_(2)O concentration,it requires two different schematic graphs to present the glass structure.The model can be extended to other binary and multiple component silicate glasses and can be experimentally verified.展开更多
Cubic metal-covalent-supramolecular organic framework(MCSOF-1)hybrid has been created from the reaction of two molecular components and subsequent co-assembly with cucurbit[8]uril(CB[8])in water.In the presence of CB[...Cubic metal-covalent-supramolecular organic framework(MCSOF-1)hybrid has been created from the reaction of two molecular components and subsequent co-assembly with cucurbit[8]uril(CB[8])in water.In the presence of CB[8],[Ru(bpy)_3]^(2+)-based acylhydrazine 1·2Cl reacted with aldehyde 2·Cl to quantitatively yield six-armed precursor 3·8Cl through the generation of MCSOF-1.MCSOF-1 combines the structural features of metal-,covalent-and supramolecular organic frameworks.Its periodicity in water and in the solid state was confirmed by synchrotron X-ray scattering and diffraction experiments.MCSOF-1could enrich discrete anionic polyoxometalates(POMs),maintain periodicity in acidic medium,and remarkably facilitate visible light-induced electron transfer from its[Ru(bpy)_3]^(2+)units to enriched POMs,leading to enhanced catalysis of the POMs for the reduction of proton to H_2in both aqueous(homogeneous)and organic(heterogeneous)media.展开更多
A water-soluble metallo-supramolecular polymer MSP-f-6Np,which possesses a regular pore aperture of 1.4 nm,has been assembled from a structurally flexible naphthalene-appended[Ru(bipy)3]^2+complex and cucurbit[8]uril....A water-soluble metallo-supramolecular polymer MSP-f-6Np,which possesses a regular pore aperture of 1.4 nm,has been assembled from a structurally flexible naphthalene-appended[Ru(bipy)3]^2+complex and cucurbit[8]uril.As the first periodic metallo-supramolecular polymer formed by a flexible building block,MSP-f-6Np exhibits a hydrodynamic diameter of 122 and 164 nm at 0.1 and 2.0 mM of the monomer concentrations.Synchrotron small angle X-ray scattering experiments confirm that MSP-f-6Np possesses porosity periodicity in both the solution and solid states.Compared with a control,the new highly ordered porous system displays enhanced photocatalytic activity for the degradation of organic dyes.展开更多
Short DNA represents an important class of bioma-cromolecules that arewidely applied in gene therapy,editing,and modulation.However,the development of simple and reliable methods for their intracellular delivery remai...Short DNA represents an important class of bioma-cromolecules that arewidely applied in gene therapy,editing,and modulation.However,the development of simple and reliable methods for their intracellular delivery remains a challenge.Herein,we describe that seven water-soluble,homogeneous supramole-cular organic frameworks(SOFs)with a well-defined pore size and high stability in water that can accom-plish in situ inclusion of single-stranded(ss)and double-stranded(ds)DNA(21,23,and 58 nt)and effective intracellular delivery(including two non-cancerous and six cancerous cell lines).展开更多
This study utilises linear-scaling density functional theory(DFT)and develops a new machine-learning potential for carbon and nitrogen(GAP-CN),based on the carbon potential(GAP20),to investigate the interaction betwee...This study utilises linear-scaling density functional theory(DFT)and develops a new machine-learning potential for carbon and nitrogen(GAP-CN),based on the carbon potential(GAP20),to investigate the interaction between carbon self-interstitials and nitrogen-vacancy(NV)centres in diamond,focusing on their excited states and diffusion behaviour.From the simulated excited states,‘Bright’,‘Spike’,and‘Dark’defect configurations are classified based on their absorption spectrum features.Furthermore,machine learning molecular dynamics simulation provides insight into the possible diffusion mechanism of Ci and NV,showing that Ci can diffuse away or recombine with NV.The study yields new insight into the formation of NV defects in diamond for quantum technology applications.展开更多
Aberration correction is an important aspect of modern high-resolution scanning transmission electron microscopy.Most methods of aligning aberration correctors require specialized sample regions and are unsuitable for...Aberration correction is an important aspect of modern high-resolution scanning transmission electron microscopy.Most methods of aligning aberration correctors require specialized sample regions and are unsuitable for fine-tuning aberrations without interrupting on-going experiments.Here,we present an automated method of correcting first-and second-order aberrations called BEACON,which uses Bayesian optimization of the normalized image variance to efficiently determine the optimal corrector settings.We demonstrate its use on gold nanoparticles and a hafnium dioxide thin film showing its versatility in nano-and atomic-scale experiments.BEACON can correct all firstand second-order aberrations simultaneously to achieve an initial alignment and first-and secondorder aberrations independently for fine alignment.Ptychographic reconstructions are used to demonstrate an improvement in probe shape and a reduction in the target aberration.展开更多
基金the National Natural Science Foundation of China (Nos.21432004,21529201,91527301)the Ministry of Science and Technology of China(No.2013CB834501)+1 种基金the Ministry of Education of China Research Fund for the Doctoral Program and of China for financial supportsupport from the Molecular Foundry,Lawrence Berkeley National Laboratory,supported by the Office of Science,Office of Basic Energy Sciences,Scientific User Facilities Division,of the U.S.Department of Energy under Contract No.DE-AC0205CH11231
文摘Four water-soluble porous supramolecular organic framework drug delivery systems（sof-DDSs） have been used to adsorb doxorubicin（DOX） in water at physiological pH of 7.4,which is driven exclusively by hydrophobicity.The resulting complexes DOX@SOFs are formed instantaneously upon dissolving the components in water.The drug-adsorbed sof-DDSs can undergo plasm circulation with important maintenance of the drug and overcome the multidrug resistance of human breast MCF-7/Adr cancer cells.DOX is released readily in the cancer cells due to the protonation of its amino group in the acidic medium of cancer cells.In vitro and in vivo experiments reveal that the delivery of SOF-a-d remarkably improve the cytotoxicity of DOX for the MCF-7/Adr cells and tumors,leading to 13-19-fold reduction of the 1C_（50）values as compared with that of DOX.This new sof-DDSs strategy omits the indispensable loading process required by most of reported nano-scaled carriers for neutral hydrophobic chemotherapeutic agents,and thus should be highly valuable for future development of low-cost delivery systems.
基金the National Natural Science Foundation of China(Nos.21432004,21529201,and 91527301)the Ministry of Science and Technology of China(No.2013CB834501)+1 种基金the Ministry of Education of China Research Fund for the Doctoral Program and of China for financial supportsupport from the Molecular Foundry,Lawrence Berkeley National Laboratory,supported by the Office of Science,Office of Basic Energy Sciences,Scientific User Facilities Division,of the U.S.Department of Energy under Contract No.DE-AC02-05CH11231
文摘Water-soluble three-dimensional porous supramolecular organic frameworks（SOFs） have been demonstrated as a new generation of homogeneous polycationic platforms for anti-cancer drug delivery.The new SOF drug delivery systems（sof-DDSs） can adsorb dianionic pemetrexed（PMX）,a clinically used chemotherapeutic agent instantaneously upon dissolving in water,which is driven by both electrostatic attraction and hydrophobicity.The in situ-prepared PMX@SOFs are highly stable and can avoid important release of the drug during plasm circulation and overcome the multidrug resistance of human breast MCF-7/Adr cancer cells to enter the cancer cells.Acidic microenvironment of cancer cells promotes the release of the drug in cancer cells.Both in vitro and in vivo studies have revealed that sofDDSs considerably improve the treatment efficacy of PMX,leading to 6-12-fold reduction of the IC50 values,as compared with that of PMX alone.The new drug delivery strategy omits the loading process required by most of reported nanoparticle-based delivery systems and thus holds promise for future development of low-cost drug delivery systems
文摘蛋白质的动态特性和结构活性对于蛋白质功能的调控具有根本意义。传统的结构确定方法(包括X射线和电子显微镜单颗粒分析技术等)往往需要成千上万不同蛋白质分子的平均信号,因此难以确定蛋白质分子的动态结构。而电子显微断层成像技术是一种对独个生物个体结构从不同的观测角度照相、并计算来恢复该个体的三维结构密度图的方法。传统的冷冻电子断层成像重构方法采用整个大尺寸电镜图像进行重构计算,通常用来研究细菌、细胞切片等大尺寸生物个体在较低分辨率下的结构;由于分辨率的限制,不足以获得小尺寸的蛋白质分子的结构细节。最近,任罡研究小组提出一种独个生物颗粒的电子显微断层成像方法(individual-particle electron tomography,IPET)。该方法通过减小图像尺寸(直至所选区域只包含单个蛋白质分子)的策略,运用提出的FETR(focused electron tomography reconstruction)算法来提高独个大分子重构的分辨率。此方法不需要初始模型和大量分子的平均信号,同时能够容忍一定的测角误差。本文综述了IPET/FETR方法在确定独个分子结构过程中的具体步骤以及如何应用该方法来研究蛋白动态特性和结构变化特征。期望通过该综述和国内同行交流,分享最新的前沿研究,为赶超世界科技前沿的建设添砖加瓦。
文摘抗体(antibody)又称免疫球蛋白(immunoglobulin,Ig),是人体免疫反应的重要参与者.了解抗体的结构和结构动态特征,是理解人体免疫作用机理、修复或提高免疫能力、定向设计抗体以治疗各种疾病的基础.本文以人体IgG1抗体为对象,综述了使用透射电子显微学方法研究IgG1抗体结构方向的最新进展.详细介绍了使用逐个分子的电子断层三维重构技术(individual-particle electron tomography,IPET)对抗体进行结构研究的方法,包括样品制备、图像处理和数据分析等.并描述了利用该技术,在研究抗体结合肽分子后的结构形变和通过收集不同构象来研究抗体动态结构特征方面所取得的阶段性成果.最后,对尚待解决的关键问题与该技术未来的发展方向进行了讨论与展望.
基金Project(cstc2020jcyj-msxm X0930) supported by the Natural Science Foundation of Chongqing,ChinaProject(KJQN201901522) supported by Technological Research Program of Chongqing Municipal Education Commission,ChinaProject(cx2020068) supported by the Venture&Innovation Support Program for Chongqing Overseas Returnees,China。
文摘A catalyst of ferroelectric-BaTiO_(3)@photoelectric-TiO_(2) nanohybrids(BaTiO_(3)@TiO_(2))with enhanced photocatalytic activity was synthesized via a hydrolysis precipitation combined with a hydrothermal approach.Compared to pure TiO_(2),pure BaTiO_(3) and BaTiO_(3)/TiO_(2) physical mixture,the heterostructured BaTiO_(3)@TiO_(2) exhibits significantly improved photocatalytic activity and cycling stability in decomposing Rhodamine B(RhB)and the degradation efficiency is 1.7 times higher than pure TiO_(2) and 7.2 times higher than pure BaTiO_(3).These results are mainly attributed to the synergy effect of photoelectric TiO_(2),ferroelectric-BaTiO_(3) and the rationally designed interfacial structure.The mesoporous microstructure of TiO_(2) is of a high specific area and enables excellent photocatalytic activity.The ferroelectric polarization induced built-in electric field in BaTiO_(3) nanoparticles,and the intimate interfacial interactions at the interface of BaTiO_(3) and TiO_(2) are effective in driving the separation and transport of photogenerated charge carriers.This strategy will stimulate the design of heterostructured photocatalysts with outstanding photocatalytic performance via interface engineering.
基金supported by the Molecular Foundry,Lawrence Berkeley National Laboratory,which is supported by the Office of Science and Office of Basic Energy Sciences of the U.S.Department of Energy under Contract No.DE-AC02-05CH11231supported by National Natural Science Foundation of China (No.51573011)+2 种基金Natural Foundation of Jiangsu Province (No. BK20150272)Beijing Laboratory of Biomedical Materialsthe scholarship support from the program of the China Scholarship Council (No.201706880022) for study at Lawrence Berkeley National Laboratory
文摘The development of polymeric optical materials with a higher refractive index,transparency in the visible spectrum region and easier processability is increasingly desirable for advanced optical applications such as microlenses,image sensors,and organic light-emitting diodes.Most acrylates have a low refractive index(around 1.50)which does not meet the high perfo rmance requirements of advanced optical materials.In this research,three novel acrylates were synthesized via a facile one-step approach and used to fabricate optical transparent polymers.All of the polymers reveal good optical properties including high transparency(≥90%)in the visible spectrum region and high refractive index values(1.6363)at 550 nm.Moreover,nanostructures of these acrylate polymers with various feature sizes including nanogratings and photonic crystals were successfully fabricated using nanoimprint lithography.These results indicate that these acrylates can be used in a wide range of optical and optoelectronic devices where nanopatterned films with high refractive index and transparency are required.
基金supported by the U.S.Army Research Office(ARO)(W911NF-18-1-0016)supported by the Basic Science Research Program(2021R1A2B5B03001615,2021M3H4A1A02099355)through the National Research Foundation of Korea(NRF)funded by the Ministry of Science,ICT and Future Planning,the Technology Innovation Program(20010960,20012216)funded by the Ministry of Trade,Industry&Energy(MOTIE)the R&D program for Forest Science Technology(FTIS 2021354D10-2123-AC03)provided by Korea Forest Service(Korea Forestry Promotion Institute).
文摘Challenges facing high-voltage/high-capacity cathodes,in addition to the longstanding problems pertinent to lithium(Li)-metal anodes,should be addressed to develop high-energy-density Li-metal batteries.This issue mostly stems from interfacial instability between electrodes and electrolytes.Conventional carbonate-or ether-based liquid electrolytes suffer from not only volatility and flammability but also limited electrochemical stability window.Here,we report a nitrile electrolyte strategy based on concentrated nitrile electrolytes(CNEs)with co-additives.The CNE consists of high-concentration lithium bis(fluorosulfonyl)imide(LiFSI)in a solvent mixture of succinonitrile(SN)/acetonitrile(AN).The SN/AN solvent mixture is designed to ensure high oxidation stability along with thermal stability,which are prerequisites for high-voltage Li-metal cells.The CNE exhibits interfacial stability with Li metals due to the coordinated solvation structure.Lithium nitrate(LiNO_(3))and indium fluoride(InF_(3))are incorporated in the CNE as synergistic co-additives to further stabilize solid-electrolyte interphase(SEI)on Li metals.The resulting electrolyte(CNE+LiNO_(3)/InF_(3))enables stable cycling performance in Li||LiNi_(0.8)Co_(0.1)Mn_(0.1)and 4.9 V-class Li||LiNi_(0.5)Mn_(1.5)O_(4)cells.Notably,the Li||LiNi_(0.5)Mn_(1.5)O_(4)cell maintains its electrochemical activity at high temperature(100℃)and even in flame without fire or explosion.
基金supported by the Assistant Secretary for Energy Efficiency and Renewable Energy,Vehicle Technologies Office,under the Advanced Battery Materials Research(BMR)Program of the U.S.Department of Energy under Contract No.DE-AC02-05CH11231support by the U.S.Department of Energy under Contract No.106298-001+2 种基金the funding from Polish Ministry of Science and Higher Education No.1670/MOB/V/2017/0funding support of SUSTechthe resources of the National Energy Research Scientific Computing Center(NERSC)that is supported by the Office of Science of the U.S.Department of Energy。
文摘The lithium-sulfur(Li-S)battery is one of the most promising substitutes for current energy storage systems because of its low cost,high theoretical capacity,and high energy density.However,the high solubility of intermediate products(i.e.,lithium polysulfides)and the resultant shuttle effect lead to rapidly fading capacity and a low coulombic efficiency,which hinder the practical application of Li-S batteries.In this study,block copolymers are constructed with both an ethylene oxide unit and a styrene unit and then used as binders for Li-S batteries.Electrochemical performance improvements are attributed to the synergistic effects contributed by the different units of the block copolymer.The ethylene oxide unit traps polysulfide,which bonds strongly with the intermediate lithium polysulfide,and enhances the transport of lithium ions to reach high capacity.Meanwhile,the styrene unit maintains cathode integrity by improving the mechanical properties and elasticity of the constructed block copolymer to accommodate the large volume changes.By enabling multiple functions via different units in the polymer chain,high sulfur utilization is achieved,polysulfide diffusion is confined,and the shuttle effect is suppressed during the cycle life of Li-S batteries,as revealed by operando ultraviolet-visible spectroscopy and S Kedge X-ray absorption spectroscopy.
基金support from the National Natural Science Foundation of China(62004129,22005202)is gratefully acknowledgedNew York University Abu Dhabi for financial support.
文摘Over the past decade,perovskite photovoltaics have approached other currently available technologies and proven to be the most prospective type of solar cells.Although the many-sided research in this very active field has generated consistent results with regard to their undisputed consistently increasing power conversion efficiency,it also produced several rather contradictory opinions.Among other important details,debate surrounding their proneness to surface degradation and poor mechanical robustness,as well as the environmental footprint of this materials class,remains a moot point.The application of ionic liquids appears as one of the potential remedies to some of these challenges due to their high conductivity,the opportunities for chemical"tuning"of the structure,and relatively lower environmental footprint.This article provides an overview,classification,and applications of ionic liquids in perovskite solar cells.We summarize the use and role of ionic liquids as versatile additives,solvents,and modifiers in perovskite precursor solution,in charge transport layer,and in interfacial and stability engineering.Finally,challenges and the future prospects for the design and/or selection of ionic liquids with a specific profile that meets the requirements for next-generation highly efficient and stable perovskite solar cells are proposed.
基金supported by the LDRD program at the LBNL and facilitated by a User Program at The Molecular Foundry(TMF)provided by the TMF clusters(managed by the High Performance Computing Services Group,at LBNL)+3 种基金by the National Energy Research Scientific Computing Center(NERSC)supported by the Office of Science of the US DOE under Contract No.DE-AC02-05CH11231support from EERE VTO under the Applied Battery Materials Program of the US DOE with Contract No.DE-AC02-05CH11231supported by the DOE VTO at Argonne National Laboratory
文摘The pre-edges of oxygen-K X-ray absorption spectra have been ubiquitous in transition metal(TM)oxide studies in various fields,especially on the fervent topic of oxygen redox states in battery electrodes.However,critical debates remain on the use of the O-K pre-edge variations upon electrochemical cycling as evidences of oxygen redox reactions,which has been a popular practice in the battery field.This study presents an investigation of the O-K pre-edge of 55 oxides covering all 3d TMs with different elements,structures,and electrochemical states through combined experimental and theoretical analyses.It is shown unambiguously that the O-K pre-edge variation in battery cathodes is dominated by changing TM-d states.Furthermore,the pre-edge enables a unique opportunity to project the lowest unoccupied TM-d states onto one common energy window,leading to a summary map of the relative energy positions of the low-lying TM states,with higher TM oxidation states at lower energies,corresponding to higher electrochemical potentials.The results naturally clarify some unusual redox reactions,such as Cr^(3+/6+).This work provides a critical clarification on O-K pre-edge interpretation and more importantly a benchmark database of O-K pre-edge for characterizing redox reactions in batteries and other energy materials.
基金the Office of Science,Office of Basic Energy Sciences,of the U.S.Department of Energy under Contract No.DE-AC02-05CH11231.
文摘The structural model of sodium silicate glass plays a crucial role in understanding the properties and the nature of binary glass and other more complicated silicate glasses.This work proposes a structural model for sodium silicate glass based on the medium-range ordering structure of silica glass and the information found from the Na_(2)O-SiO_(2) phase diagram.This new model is different from previous ones.First,the sodium silica glass is both structurally and chemically heterogeneous on the nanometer scale.Secondly,the sodium cation distribution is Na_(2)O concentration-dependent.In order to reflect the structural change with Na_(2)O concentration,it requires two different schematic graphs to present the glass structure.The model can be extended to other binary and multiple component silicate glasses and can be experimentally verified.
基金supported by the National Natural Science Foundation of China (21529201, 21432004, 91527301)the Molecular Foundry, Lawrence Berkeley National Laboratory, and the Office of Science, Office of Basic Energy Sciences, Scientific User Facilities Division, of the U.S. Department of Energy (DE-AC02- 05CH11231)
文摘Cubic metal-covalent-supramolecular organic framework(MCSOF-1)hybrid has been created from the reaction of two molecular components and subsequent co-assembly with cucurbit[8]uril(CB[8])in water.In the presence of CB[8],[Ru(bpy)_3]^(2+)-based acylhydrazine 1·2Cl reacted with aldehyde 2·Cl to quantitatively yield six-armed precursor 3·8Cl through the generation of MCSOF-1.MCSOF-1 combines the structural features of metal-,covalent-and supramolecular organic frameworks.Its periodicity in water and in the solid state was confirmed by synchrotron X-ray scattering and diffraction experiments.MCSOF-1could enrich discrete anionic polyoxometalates(POMs),maintain periodicity in acidic medium,and remarkably facilitate visible light-induced electron transfer from its[Ru(bpy)_3]^(2+)units to enriched POMs,leading to enhanced catalysis of the POMs for the reduction of proton to H_2in both aqueous(homogeneous)and organic(heterogeneous)media.
基金supported by the National Natural Science Foundation of China (21432004, 21529201, 21890732)the support by the Molecular Foundry, the Office of Science, Office of Basic Energy Sciences, of the U.S.+2 种基金Department of Energy (DE-AC0205CH11231)support by the National Institute of General Medical Sciences (NIGMS) project advanced light sources efficiently networking advanced beam line experiments (ALS-ENABLE) (P30 GM124169)a High-End Instrumentation(S10OD018483)
文摘A water-soluble metallo-supramolecular polymer MSP-f-6Np,which possesses a regular pore aperture of 1.4 nm,has been assembled from a structurally flexible naphthalene-appended[Ru(bipy)3]^2+complex and cucurbit[8]uril.As the first periodic metallo-supramolecular polymer formed by a flexible building block,MSP-f-6Np exhibits a hydrodynamic diameter of 122 and 164 nm at 0.1 and 2.0 mM of the monomer concentrations.Synchrotron small angle X-ray scattering experiments confirm that MSP-f-6Np possesses porosity periodicity in both the solution and solid states.Compared with a control,the new highly ordered porous system displays enhanced photocatalytic activity for the degradation of organic dyes.
基金We thank the National Natural Science Foundation of China(Nos.21432004 and 21529201)for financial sup-port,Shanghai Synchrotron Radiation Facility for provid-ing BL16B1 and BL14B1 beamlines for collecting the synchrotron X-ray-scattering and diffraction data,and the SIBYLS Beamline 12.3.1 of the Advanced Light Source(ALS),Lawrence Berkeley National Laboratory,for collecting solution-phase,synchrotron small-angle X-ray-scattering data.
文摘Short DNA represents an important class of bioma-cromolecules that arewidely applied in gene therapy,editing,and modulation.However,the development of simple and reliable methods for their intracellular delivery remains a challenge.Herein,we describe that seven water-soluble,homogeneous supramole-cular organic frameworks(SOFs)with a well-defined pore size and high stability in water that can accom-plish in situ inclusion of single-stranded(ss)and double-stranded(ds)DNA(21,23,and 58 nt)and effective intracellular delivery(including two non-cancerous and six cancerous cell lines).
基金the use of the University of Oxford Advanced Research Computing(ARC)facility in carrying out this work(https://doi.org/10.5281/zenodo.22558).Additionally,we acknowledge the use of NQIT computing nodes and the Quantum Computing and Simulation Hub.J.C.A.P.acknowledges the support of St.Edmund Hall,University of Oxford,through the Cooksey Early Career Teaching and Research Fellowship,and the embedded CSE programme of the ARCHER UK National Supercomputing Service.We extend our thanks to Yuxing Zhou for valuable suggestions on ML potential training,to Xingrui Cheng for providing experimental data,and to Jacx Chan for offering meaningful insights for this work.
文摘This study utilises linear-scaling density functional theory(DFT)and develops a new machine-learning potential for carbon and nitrogen(GAP-CN),based on the carbon potential(GAP20),to investigate the interaction between carbon self-interstitials and nitrogen-vacancy(NV)centres in diamond,focusing on their excited states and diffusion behaviour.From the simulated excited states,‘Bright’,‘Spike’,and‘Dark’defect configurations are classified based on their absorption spectrum features.Furthermore,machine learning molecular dynamics simulation provides insight into the possible diffusion mechanism of Ci and NV,showing that Ci can diffuse away or recombine with NV.The study yields new insight into the formation of NV defects in diamond for quantum technology applications.
基金funded by the US Department of Energy in the program "Electron Distillery 2.0: Massive Electron Microscopy Data to Useful Information with AI/ML."Work at the Molecular Foundry was supported by the Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231+1 种基金This research used resources of the National Energy Research Scientific Computing Center (NERSC), a Department of Energy Office of Science User Facility using NERSC award BES-ERCAP0028035S.M.R. and C.O. acknowledge support from the U.S. Department of Energy Early Career Research Award program. J.P. acknowledges financial support from the National Research Foundation of Korea (NRF) grant, funded by the Korea government (MSIT) (Grant No. RS-2023-00283902, and RS-202400408823). We gratefully acknowledge CEOS, GmbH for providing the server enabling communication with the corrector and I. Massmann for technical assistance.
文摘Aberration correction is an important aspect of modern high-resolution scanning transmission electron microscopy.Most methods of aligning aberration correctors require specialized sample regions and are unsuitable for fine-tuning aberrations without interrupting on-going experiments.Here,we present an automated method of correcting first-and second-order aberrations called BEACON,which uses Bayesian optimization of the normalized image variance to efficiently determine the optimal corrector settings.We demonstrate its use on gold nanoparticles and a hafnium dioxide thin film showing its versatility in nano-and atomic-scale experiments.BEACON can correct all firstand second-order aberrations simultaneously to achieve an initial alignment and first-and secondorder aberrations independently for fine alignment.Ptychographic reconstructions are used to demonstrate an improvement in probe shape and a reduction in the target aberration.
