Discovery of materials using“bottom-up”or“top-down”approach is of great interest in materials science.Layered materials consisting of two-dimensional(2D)building blocks provide a good platform to explore new mater...Discovery of materials using“bottom-up”or“top-down”approach is of great interest in materials science.Layered materials consisting of two-dimensional(2D)building blocks provide a good platform to explore new materials in this respect.In van der Waals(vdW)layered materials,these building blocks are charge neutral and can be isolated from their bulk phase(top-down),but usually grow on substrate.In ionic layered materials,they are charged and usually cannot exist independently but can serve as motifs to construct new materials(bottom-up).In this paper,we introduce our recently constructed databases for 2D material-substrate interface(2DMSI),and 2D charged building blocks.For 2DMSI database,we systematically build a workflow to predict appropriate substrates and their geometries at substrates,and construct the 2DMSI database.For the 2D charged building block database,1208 entries from bulk material database are identified.Information of crystal structure,valence state,source,dimension and so on is provided for each entry with a json format.We also show its application in designing and searching for new functional layered materials.The 2DMSI database,building block database,and designed layered materials are available in Science Data Bank at https://doi.org/10.57760/sciencedb.j00113.00188.展开更多
The design and synthesis of high-nuclear polyoxometalates(POMs)utilizing secondary building blocks(SBB)is attractive and challenging.Herein,four new high-nuclear polyoxovanadates(POVs),{V_(20)S_(2)In_(42)P_(12)(CO_(2)...The design and synthesis of high-nuclear polyoxometalates(POMs)utilizing secondary building blocks(SBB)is attractive and challenging.Herein,four new high-nuclear polyoxovanadates(POVs),{V_(20)S_(2)In_(42)P_(12)(CO_(2))}(1),{V_(20)Mo_(2)In_(4)P_(12)(C_(2)O_(4))_(2)}(2),{V_(12)P_(6)SPb_(2)}(3)and{V_(12)P_(6)SCd_(2)}(4),were successfully synthesized under solvothermal conditions by incorporating transition metals into POVs.All the structures are constructed from the tetragonal{V_(5)(PhPO_(3))_(4)}SBB,wherein five{VO_(5)}square pyramids are interconnected by edge-sharing modes,and four phenylphosphonic acid ligands further coordinate with vanadium cations.Compounds 1 and 2 have similar structures in which two{V_(10)(PhPO_(3))_(6)(SO_(4))In_(2)}or{V_(10)(PhPO_(3))_(6)(MoO_(4))In_(2)}clusters are bridged by formate or oxalate ligands.While compounds 3 and 4 are constructed from{V_(12)(PhPO_(3))_(6)(SO_(4))}cluster doped with transition metals Pb or Cd.Notably,compound 4 demonstrated efficient catalytic activity for sulfide oxidation.展开更多
Neuroscience,neuroprosthetics and neural regeneration would benefit from more adequate interfacing devices.To understand how neurons communicate,process information and control behavior,researchers need to monitor ner...Neuroscience,neuroprosthetics and neural regeneration would benefit from more adequate interfacing devices.To understand how neurons communicate,process information and control behavior,researchers need to monitor nerve cell activity with high specifity and high spatio-temporal resolution.Neural prostheses require minimally invasive-implantable devices to re- place lost function, and bypass dysfunctional pathways in the nervous system. Devices built to repair damaged nerves have to support and promote regeneration of host neurons through an injured area. Finally, as neuromodulation is being elevated from last resort to first choice treatment for an increasing number of conditions, implantable devices able to perform targeted regu- lation of neural activity are needed. Recent advances in device miniaturization, materials engineering, and nanotechnology are enabling development of an increasing number of devices that effectively interface with neural circuits. Wireless spinal cord and deep brain stimulators, retinal and cochlear implants, high density electrodes arrays for neural recording have already proven to significantly impact fundamental research in neuro- science, as well as individuals＇ quality of life.展开更多
New fully biobased polyether/esters have been synthesized by a one-pot polymerization reaction of ricinoleic acid(RA),vanillic acid(VA)and ethylene carbonate(EC).In particular,EC selectively reacts with the phenolic g...New fully biobased polyether/esters have been synthesized by a one-pot polymerization reaction of ricinoleic acid(RA),vanillic acid(VA)and ethylene carbonate(EC).In particular,EC selectively reacts with the phenolic group of VA to obtain in-situ 4-(2-hydroxyethoxy)-3-methoxybenzoate(EV),suitable for subsequent copolymerization with RA.The procedure was carried out in a single step,without any solvent.Chemical structure and thermal properties of the new materials were studied in order to explore relationships between composition and final performances.The combination of EV,bearing a rigid aromatic structure,with RA,characterized by high flexibility and potential biocidal activity,allows the production of a novel class of fully biobased aliphatic-aromatic polymers presenting tuneable thermal properties and suitable for a range of applications,for example,in active packaging and biomedical fields.展开更多
Appropriate schemata as a novel concept to characterize building blocks are introduced, and then, the traits of appropriate schemata are presented. The effects of building blocks by search operators are analyzed. Henc...Appropriate schemata as a novel concept to characterize building blocks are introduced, and then, the traits of appropriate schemata are presented. The effects of building blocks by search operators are analyzed. Hence, the experiments on RR-8X8 are employed to verify that appropriate schemata construct the building blocks. The validity of appropriate schemata and building blocks from the views of theory and practice is presented.展开更多
Building Blocks Funeka Yazini AprilAfrican governments, not the Americans or the Chinese, have the key responsibility to become the drivers of their own industrial and agricul- tural development. There- fore, it is ur...Building Blocks Funeka Yazini AprilAfrican governments, not the Americans or the Chinese, have the key responsibility to become the drivers of their own industrial and agricul- tural development. There- fore, it is urgent that African governments prioritize the objectives of the Johannes- burg Summit of the Forum on China-Africa Cooperation （FOCAC） domestically and regionally.展开更多
This paper proposes a Linkage Learning Genetic Algorithm(LLGA)based on the messy Genetic Algorithm(mGA)to optimize the Min-Max fuel controller performance in Gas Turbine Engine(GTE).For this purpose,a GTE fuel control...This paper proposes a Linkage Learning Genetic Algorithm(LLGA)based on the messy Genetic Algorithm(mGA)to optimize the Min-Max fuel controller performance in Gas Turbine Engine(GTE).For this purpose,a GTE fuel controller Simulink model based on the Min-Max selection strategy is firstly built.Then,the objective function that considers both performance indices(response time and fuel consumption)and penalty items(fluctuation,tracking error,overspeed and acceleration/deceleration)is established to quantify the controller performance.Next,the task to optimize the fuel controller is converted to find the optimization gains combination that could minimize the objective function while satisfying constraints and limitations.In order to reduce the optimization time and to avoid trapping in the local optimums,two kinds of building block detection methods including lower fitness value method and bigger fitness value change method are proposed to determine the most important bits which have more contribution on fitness value of the chromosomes.Then the procedures to apply LLGA in controller gains tuning are specified stepwise and the optimization results in runway condition are depicted subsequently.Finally,the comparison is made between the LLGA and the simple GA in GTE controller optimization to confirm the effectiveness of the proposed approach.The results show that the LLGA method can get better solution than simple GA within the same iterations or optimization time.The extension applications of the LLGA method in other flight conditions and the complete flight mission simulation will be carried out in partⅡ.展开更多
A novel three-dimensional（3D） supramolecular architecture, {[Nd（OH-BDC）（OH-HBDC）（H2O）2]·2HaO）n（1） （OH-H2BDC=5-hydroxyisophthalic acid）, which was formed through hydrogen bonds and π-π stacking betw...A novel three-dimensional（3D） supramolecular architecture, {[Nd（OH-BDC）（OH-HBDC）（H2O）2]·2HaO）n（1） （OH-H2BDC=5-hydroxyisophthalic acid）, which was formed through hydrogen bonds and π-π stacking between two-dimensional（2D） layers, was hydrothermally synthesized and characterized by single-crystal X-ray diffraction. Windmill building blocks, which consist of two nine-coordinated metal centers and four OH-H2BDC groups are connected through two carboxyl groups, to lead to a one-dimensional infinite inorganic chain（… M--O--C--O--M…） along the [100] direction. An observed intense blue luminescence with an emission band peaked at 390 nm for compound 1 may results from ligand-to-metal charge transfer（LMCT）. Variable-temperature magnetic susceptibility of compound 1 was investigated and the value was deviated from the Curie-Weiss law.展开更多
Two chiral building blocks 1 and 2 for anti-and syn-1, 3-diols has been achieved in 8 steps and 7 steps respectively, starting from the readily available and inexpensive D (+)-xylose 3.
Since the 1990s,femtosecond laser two-photon absorption(TPA),which enables point-by-point photopolymerization,has been a tool for making threedimensional(3D)microstructures.Approximately 10 years later,Kawata et al.im...Since the 1990s,femtosecond laser two-photon absorption(TPA),which enables point-by-point photopolymerization,has been a tool for making threedimensional(3D)microstructures.Approximately 10 years later,Kawata et al.improved the spatial resolution of TPA fabrication to120 nm,far beyond the diffraction limit of the 780 nm laser source.1 The essential mechanism of this nanoscale fabrication lies in the nonlinear effect,in which TPA-induced photopolymerization occurs only in the vicinity of the focal spot.展开更多
Highly reduced molybdenum red(MR)clusters have emerged as a new type of polyoxomolybdates(POMos)and showed great potential as electron/proton reservoirs for energy conversion and storage,as well as for catalysis.Howev...Highly reduced molybdenum red(MR)clusters have emerged as a new type of polyoxomolybdates(POMos)and showed great potential as electron/proton reservoirs for energy conversion and storage,as well as for catalysis.However,the limited structural diversity of MR clusters significantly hinders further exploration of their potential as functional materials.Herein,we describe the synthesis of a novel highly reduced MR cluster{Mo_(49)}(compound 1)based on rational assembly of a variety of basic building blocks(BBs).In addition to the well-established BBs found in the family of MR clusters,the unique tetrahedral{MoVI 4}BB plays a key role in directing the assembly to afford trigonal pyramid-like structure of compound 1,which consists of 49 Mo and 148 O atoms with a high reduction degree of 73%.Moreover,at 80℃and 98%relative humidity(RH),the pellet sample of compound 1 displays good proton conductivity of 7.88×10^(-3)S/cm owing to the efficient hydrogen-bonded network built from the surface oxygen atoms,protons and vip water molecules.This research offers new insights into the assembly and synthesis of MR clusters through a BB strategy and manifests their significant potential for advanced applications.展开更多
Starting from the oxygenated piperidine building block 20,two synthetic approaches to new building blocks (8R,8aS)-and (8R,8aR)-8-hydroxy-5-indolizidinones 19a/19b and 15a/15b have been developed,respectively. The fir...Starting from the oxygenated piperidine building block 20,two synthetic approaches to new building blocks (8R,8aS)-and (8R,8aR)-8-hydroxy-5-indolizidinones 19a/19b and 15a/15b have been developed,respectively. The first one is based on the trans-diastereoselective reductive alkylation (dr = 93:7),followed by a four-step procedure; and the second one called for the RCM reaction on the N,O-acetal derived from a vinylation,which was followed by a pyrrole formation,and a stereocontrolled cis-selective (dr = 91:9) catalytic hydrogenation. Reduction of the diastereomer 15a produced (8R,8aR)-8-indolizidinol (18).展开更多
1 Results Carbon nanotubes (CNTs) have fascinating properties.In order to use these novel one-dimensional structures for applications such as in nano-electronic,nano-mechanical and electrochemical energy storage devic...1 Results Carbon nanotubes (CNTs) have fascinating properties.In order to use these novel one-dimensional structures for applications such as in nano-electronic,nano-mechanical and electrochemical energy storage device and as structural elements in various composites,the structure of nanotubes needs to be tailored and various architectures and macroscale assembles have to be configured using nanotube building blocks.Nanotube macrostructures are macroscopically organized groups of CNTs,which are expecte...展开更多
We introduce the concept of Canonical Workflow Building Blocks(CWBB),a methodology of describing and wrapping computational tools,in order for them to be utilised in a reproducible manner from multiple workflow langua...We introduce the concept of Canonical Workflow Building Blocks(CWBB),a methodology of describing and wrapping computational tools,in order for them to be utilised in a reproducible manner from multiple workflow languages and execution platforms.The concept is implemented and demonstrated with the BioExcel Building Blocks library(BioBB),a collection of tool wrappers in the field of computational biomolecular simulation.Interoperability across different workflow languages is showcased through a protein Molecular Dynamics setup transversal workflow,built using this library and run with 5 different Workflow Manager Systems(WfMS).We argue such practice is a necessary requirement for FAIR Computational Workflows and an element of Canonical Workflow Frameworks for Research(CWFR)in order to improve widespread adoption and reuse of computational methods across workflow language barriers.展开更多
The tobacco epidemic is a global challenge demanding concerted global and national action. Recognizing that globalization is accelerating the epidemic’s spread and perceiving the limits of national action to contain ...The tobacco epidemic is a global challenge demanding concerted global and national action. Recognizing that globalization is accelerating the epidemic’s spread and perceiving the limits of national action to contain a public health problem with transnational dimensions, Member States of the World Health Organization negotiated and adopted a unique public health treaty for tobacco control. Today, the WHO FCTC contains the blueprint for coordinated global action to address one of the most significant risks to health.展开更多
The principle of reticular chemistry has been widely used to guide the design of crystalline porous materials such as metal organic frameworks(MOFs)and covalent organic frameworks(COFs).While in the early strategies o...The principle of reticular chemistry has been widely used to guide the design of crystalline porous materials such as metal organic frameworks(MOFs)and covalent organic frameworks(COFs).While in the early strategies only the symmetries of the building blocks were considered for reticular synthesis of COFs,recently a few researches on COFs with hierarchical porosities indicate that connecting sequence of building blocks also plays a crucial role in determining crystalline structures of COFs.However,this important phenomenon has not been systematically investigated yet.In this article,a model system has been established to demonstrate how different connecting sequences of two C_(2v)-symmetric building blocks lead to the formation of four two-dimensional(2D)COFs with distinct framework structures.To verify this concept,target synthesis was conducted to produce three COFs,whose structures were confirmed by powder X-ray diffraction and pore size distribution analysis.展开更多
Covalent organic frameworks(COFs)are two-(2D)or threedimensional(3D)crystalline,porous networks generated by reversible polymerization of organic building blocks[1,2].The structures and functionalities of COFs are pre...Covalent organic frameworks(COFs)are two-(2D)or threedimensional(3D)crystalline,porous networks generated by reversible polymerization of organic building blocks[1,2].The structures and functionalities of COFs are precisely controlled via appropriately selected organic building blocks.This design imparts unique properties to COFs,including exceptional structural stability,tunable pore structure,and surface chemical activity,making them promising for gas separation,catalysis,optoelectronics,and sensing applications.Since Yaghi et al.'s seminal report on COFs in 2005[2],these frameworks have swiftly emerged as a hotspot in the field of materials.Originally,the focus was on fabricating rigid frameworks with static structures and optoelectronic properties.However,the inherently static nature of these frameworks hinders their responsiveness to external stimuli,potentially constraining their functionality in specific applications.Hence,an increasing number of researchers are now directing their attention toward the development of dynamic COFs capable of modifying their structures in response to external stimuli[3].Specifically,dynamic 2D COFs exhibiting enhanced structural responsiveness are of particular interest due to their capability to integrate switchable geometries and porosities with semiconductor building blocks,as well as electron conjugation across COF layers and π-stacked columns,which may enable stimuli-responsive electronic and spin properties[4].展开更多
Nonfused ring electron acceptors(NFREAs)have attracted much attention due to their concise synthetic routes and low cost.However,developing high-performance NFREAs with simple structure remains a great challenge.In th...Nonfused ring electron acceptors(NFREAs)have attracted much attention due to their concise synthetic routes and low cost.However,developing high-performance NFREAs with simple structure remains a great challenge.In this work,a simple building block(POBT)with noncovalently conformational locks(No CLs)was designed and synthesized.Single-crystal X-ray study indicated the presence of S…O NOCLs in POBT,thus enabling it to possess a coplanar conformation comparable to that of fused-ring CPT.Two novel NFREAs based on CPT and POBT were developed,namely TT-CPT and TT-POBT,respectively.Besides,TT-POBT possessed a smaller Stokes shift and a reduced reorganization energy compared with TT-CPT,indicating the introduction of S…O No CLs can enhance the molecular rigidity even if simplifying the molecular structure.As a result,the TT-POBT-based PSC device afforded an impressive power conversion efficiency of 11.15%,much higher than that of TT-CPT counterpart(7.03%),mainly resulting from the tighterπ-πstacking,improved and balanced charge transport,and more favorable film morphology.This work demonstrates the potential of the simple building block POBT with No CLs towards constructing low-cost and highperformance NFREAs.展开更多
To date, the high power arc plasma technology is widely used. A next generation high power arc plasma system based on building block structure is presented. The whole arc plasma inverter system is composed of 12 paral...To date, the high power arc plasma technology is widely used. A next generation high power arc plasma system based on building block structure is presented. The whole arc plasma inverter system is composed of 12 paralleled units to increase the system output capability. The hierarchical control system is adopted to improve the reliability and flexibility of the high power arc plasma inverter. To ensure the reliable turn on and off of the IGBT module in each building block unit, a special pulse drive circuit is designed by using pulse transformer. The experimental result indicates that the high power arc plasma inverter system can transfer 300 kW arc plasma energy reliably with high efficiency.展开更多
The development of donor-acceptor(D-A)type conjugated polymers depends largely on the design of novel A building blocks.Herein,we report a novel A building block based on the cyano-substituted organoboron unit(SBN-3)....The development of donor-acceptor(D-A)type conjugated polymers depends largely on the design of novel A building blocks.Herein,we report a novel A building block based on the cyano-substituted organoboron unit(SBN-3).Compared with the most common fluorine-substituted B←N unit,SBN-3 displays a significantly downshifted LUMO energy level because of the strong electron-withdrawing ability of cyano groups.In addition,due to the greater impact of cyano substitution on LUMO than on HOMO,SBN-3 exhibits a reduced band gap,nearinfrared absorption and fluorescence properties.The D-A type conjugated polymers based on the cyano-substituted B←N unit with thiophene-based units show narrow optical band gaps of ca.1.3 e V as well as distinctive electronic structures,i.e.,delocalized LUMOs and localized HOMOs.This work thus provides not only an effective approach to design strong A units but also a new electron-deficient building block for D-A type conjugated polymers.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61888102,52272172,and 52102193)the Major Program of the National Natural Science Foundation of China(Grant No.92163206)+2 种基金the National Key Research and Development Program of China(Grant Nos.2021YFA1201501 and 2022YFA1204100)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB30000000)the Fundamental Research Funds for the Central Universities.
文摘Discovery of materials using“bottom-up”or“top-down”approach is of great interest in materials science.Layered materials consisting of two-dimensional(2D)building blocks provide a good platform to explore new materials in this respect.In van der Waals(vdW)layered materials,these building blocks are charge neutral and can be isolated from their bulk phase(top-down),but usually grow on substrate.In ionic layered materials,they are charged and usually cannot exist independently but can serve as motifs to construct new materials(bottom-up).In this paper,we introduce our recently constructed databases for 2D material-substrate interface(2DMSI),and 2D charged building blocks.For 2DMSI database,we systematically build a workflow to predict appropriate substrates and their geometries at substrates,and construct the 2DMSI database.For the 2D charged building block database,1208 entries from bulk material database are identified.Information of crystal structure,valence state,source,dimension and so on is provided for each entry with a json format.We also show its application in designing and searching for new functional layered materials.The 2DMSI database,building block database,and designed layered materials are available in Science Data Bank at https://doi.org/10.57760/sciencedb.j00113.00188.
基金financially supported by National Natural Science Foundation of China(22371032 and 22271023)
文摘The design and synthesis of high-nuclear polyoxometalates(POMs)utilizing secondary building blocks(SBB)is attractive and challenging.Herein,four new high-nuclear polyoxovanadates(POVs),{V_(20)S_(2)In_(42)P_(12)(CO_(2))}(1),{V_(20)Mo_(2)In_(4)P_(12)(C_(2)O_(4))_(2)}(2),{V_(12)P_(6)SPb_(2)}(3)and{V_(12)P_(6)SCd_(2)}(4),were successfully synthesized under solvothermal conditions by incorporating transition metals into POVs.All the structures are constructed from the tetragonal{V_(5)(PhPO_(3))_(4)}SBB,wherein five{VO_(5)}square pyramids are interconnected by edge-sharing modes,and four phenylphosphonic acid ligands further coordinate with vanadium cations.Compounds 1 and 2 have similar structures in which two{V_(10)(PhPO_(3))_(6)(SO_(4))In_(2)}or{V_(10)(PhPO_(3))_(6)(MoO_(4))In_(2)}clusters are bridged by formate or oxalate ligands.While compounds 3 and 4 are constructed from{V_(12)(PhPO_(3))_(6)(SO_(4))}cluster doped with transition metals Pb or Cd.Notably,compound 4 demonstrated efficient catalytic activity for sulfide oxidation.
文摘Neuroscience,neuroprosthetics and neural regeneration would benefit from more adequate interfacing devices.To understand how neurons communicate,process information and control behavior,researchers need to monitor nerve cell activity with high specifity and high spatio-temporal resolution.Neural prostheses require minimally invasive-implantable devices to re- place lost function, and bypass dysfunctional pathways in the nervous system. Devices built to repair damaged nerves have to support and promote regeneration of host neurons through an injured area. Finally, as neuromodulation is being elevated from last resort to first choice treatment for an increasing number of conditions, implantable devices able to perform targeted regu- lation of neural activity are needed. Recent advances in device miniaturization, materials engineering, and nanotechnology are enabling development of an increasing number of devices that effectively interface with neural circuits. Wireless spinal cord and deep brain stimulators, retinal and cochlear implants, high density electrodes arrays for neural recording have already proven to significantly impact fundamental research in neuro- science, as well as individuals＇ quality of life.
文摘New fully biobased polyether/esters have been synthesized by a one-pot polymerization reaction of ricinoleic acid(RA),vanillic acid(VA)and ethylene carbonate(EC).In particular,EC selectively reacts with the phenolic group of VA to obtain in-situ 4-(2-hydroxyethoxy)-3-methoxybenzoate(EV),suitable for subsequent copolymerization with RA.The procedure was carried out in a single step,without any solvent.Chemical structure and thermal properties of the new materials were studied in order to explore relationships between composition and final performances.The combination of EV,bearing a rigid aromatic structure,with RA,characterized by high flexibility and potential biocidal activity,allows the production of a novel class of fully biobased aliphatic-aromatic polymers presenting tuneable thermal properties and suitable for a range of applications,for example,in active packaging and biomedical fields.
文摘Appropriate schemata as a novel concept to characterize building blocks are introduced, and then, the traits of appropriate schemata are presented. The effects of building blocks by search operators are analyzed. Hence, the experiments on RR-8X8 are employed to verify that appropriate schemata construct the building blocks. The validity of appropriate schemata and building blocks from the views of theory and practice is presented.
文摘Building Blocks Funeka Yazini AprilAfrican governments, not the Americans or the Chinese, have the key responsibility to become the drivers of their own industrial and agricul- tural development. There- fore, it is urgent that African governments prioritize the objectives of the Johannes- burg Summit of the Forum on China-Africa Cooperation （FOCAC） domestically and regionally.
文摘This paper proposes a Linkage Learning Genetic Algorithm(LLGA)based on the messy Genetic Algorithm(mGA)to optimize the Min-Max fuel controller performance in Gas Turbine Engine(GTE).For this purpose,a GTE fuel controller Simulink model based on the Min-Max selection strategy is firstly built.Then,the objective function that considers both performance indices(response time and fuel consumption)and penalty items(fluctuation,tracking error,overspeed and acceleration/deceleration)is established to quantify the controller performance.Next,the task to optimize the fuel controller is converted to find the optimization gains combination that could minimize the objective function while satisfying constraints and limitations.In order to reduce the optimization time and to avoid trapping in the local optimums,two kinds of building block detection methods including lower fitness value method and bigger fitness value change method are proposed to determine the most important bits which have more contribution on fitness value of the chromosomes.Then the procedures to apply LLGA in controller gains tuning are specified stepwise and the optimization results in runway condition are depicted subsequently.Finally,the comparison is made between the LLGA and the simple GA in GTE controller optimization to confirm the effectiveness of the proposed approach.The results show that the LLGA method can get better solution than simple GA within the same iterations or optimization time.The extension applications of the LLGA method in other flight conditions and the complete flight mission simulation will be carried out in partⅡ.
基金the National Natural Science Foundation of China(Nos.20371007 and 20476011)
文摘A novel three-dimensional（3D） supramolecular architecture, {[Nd（OH-BDC）（OH-HBDC）（H2O）2]·2HaO）n（1） （OH-H2BDC=5-hydroxyisophthalic acid）, which was formed through hydrogen bonds and π-π stacking between two-dimensional（2D） layers, was hydrothermally synthesized and characterized by single-crystal X-ray diffraction. Windmill building blocks, which consist of two nine-coordinated metal centers and four OH-H2BDC groups are connected through two carboxyl groups, to lead to a one-dimensional infinite inorganic chain（… M--O--C--O--M…） along the [100] direction. An observed intense blue luminescence with an emission band peaked at 390 nm for compound 1 may results from ligand-to-metal charge transfer（LMCT）. Variable-temperature magnetic susceptibility of compound 1 was investigated and the value was deviated from the Curie-Weiss law.
文摘Two chiral building blocks 1 and 2 for anti-and syn-1, 3-diols has been achieved in 8 steps and 7 steps respectively, starting from the readily available and inexpensive D (+)-xylose 3.
基金supported by the National Key R&D Program of China(no.2022YFB4600400)the National Natural Science Foundation of China(nos.T2325014,62205174,and 623B2042).
文摘Since the 1990s,femtosecond laser two-photon absorption(TPA),which enables point-by-point photopolymerization,has been a tool for making threedimensional(3D)microstructures.Approximately 10 years later,Kawata et al.improved the spatial resolution of TPA fabrication to120 nm,far beyond the diffraction limit of the 780 nm laser source.1 The essential mechanism of this nanoscale fabrication lies in the nonlinear effect,in which TPA-induced photopolymerization occurs only in the vicinity of the focal spot.
基金National Natural Science Foundation of China(Nos.92161111 and 21901038)Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning,ChinaInternational Cooperation Fund of Science and Technology Commission of Shanghai Municipality,China(No.21130750100)。
文摘Highly reduced molybdenum red(MR)clusters have emerged as a new type of polyoxomolybdates(POMos)and showed great potential as electron/proton reservoirs for energy conversion and storage,as well as for catalysis.However,the limited structural diversity of MR clusters significantly hinders further exploration of their potential as functional materials.Herein,we describe the synthesis of a novel highly reduced MR cluster{Mo_(49)}(compound 1)based on rational assembly of a variety of basic building blocks(BBs).In addition to the well-established BBs found in the family of MR clusters,the unique tetrahedral{MoVI 4}BB plays a key role in directing the assembly to afford trigonal pyramid-like structure of compound 1,which consists of 49 Mo and 148 O atoms with a high reduction degree of 73%.Moreover,at 80℃and 98%relative humidity(RH),the pellet sample of compound 1 displays good proton conductivity of 7.88×10^(-3)S/cm owing to the efficient hydrogen-bonded network built from the surface oxygen atoms,protons and vip water molecules.This research offers new insights into the assembly and synthesis of MR clusters through a BB strategy and manifests their significant potential for advanced applications.
基金the NSF of China (20672089, 20832005)the NFFTBS (J1030415)the National Basic Research Program of China (973 Program, 2010CB833200)
文摘Starting from the oxygenated piperidine building block 20,two synthetic approaches to new building blocks (8R,8aS)-and (8R,8aR)-8-hydroxy-5-indolizidinones 19a/19b and 15a/15b have been developed,respectively. The first one is based on the trans-diastereoselective reductive alkylation (dr = 93:7),followed by a four-step procedure; and the second one called for the RCM reaction on the N,O-acetal derived from a vinylation,which was followed by a pyrrole formation,and a stereocontrolled cis-selective (dr = 91:9) catalytic hydrogenation. Reduction of the diastereomer 15a produced (8R,8aR)-8-indolizidinol (18).
文摘1 Results Carbon nanotubes (CNTs) have fascinating properties.In order to use these novel one-dimensional structures for applications such as in nano-electronic,nano-mechanical and electrochemical energy storage device and as structural elements in various composites,the structure of nanotubes needs to be tailored and various architectures and macroscale assembles have to be configured using nanotube building blocks.Nanotube macrostructures are macroscopically organized groups of CNTs,which are expecte...
基金a project funded by the European Union contracts H2020-INFRAEDI-02-2018823830,and H2020-EINFRA-2015-1675728funded through EOSC-Life(https://www.eosc-life.eu)contract H2020-INFRAEOSC-2018-2824087ELIXIR-CONVERGE(https://elixir-europe.org)contract H2020-INFRADEV-2019-2871075.
文摘We introduce the concept of Canonical Workflow Building Blocks(CWBB),a methodology of describing and wrapping computational tools,in order for them to be utilised in a reproducible manner from multiple workflow languages and execution platforms.The concept is implemented and demonstrated with the BioExcel Building Blocks library(BioBB),a collection of tool wrappers in the field of computational biomolecular simulation.Interoperability across different workflow languages is showcased through a protein Molecular Dynamics setup transversal workflow,built using this library and run with 5 different Workflow Manager Systems(WfMS).We argue such practice is a necessary requirement for FAIR Computational Workflows and an element of Canonical Workflow Frameworks for Research(CWFR)in order to improve widespread adoption and reuse of computational methods across workflow language barriers.
文摘The tobacco epidemic is a global challenge demanding concerted global and national action. Recognizing that globalization is accelerating the epidemic’s spread and perceiving the limits of national action to contain a public health problem with transnational dimensions, Member States of the World Health Organization negotiated and adopted a unique public health treaty for tobacco control. Today, the WHO FCTC contains the blueprint for coordinated global action to address one of the most significant risks to health.
基金We thank the National Natural Science Foundation of China(Nos.21632004,51578224)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB20020000)Key Laboratory of Synthetic and Self-Assembly Chemistry for Organic Functional Molecules,Chinese Academy of Sciences(No.K2018-2)for financial support.C.Qian is grateful for support from H unan Provincial Innovation Foundation for Postgraduate(No.CX2016B119).
文摘The principle of reticular chemistry has been widely used to guide the design of crystalline porous materials such as metal organic frameworks(MOFs)and covalent organic frameworks(COFs).While in the early strategies only the symmetries of the building blocks were considered for reticular synthesis of COFs,recently a few researches on COFs with hierarchical porosities indicate that connecting sequence of building blocks also plays a crucial role in determining crystalline structures of COFs.However,this important phenomenon has not been systematically investigated yet.In this article,a model system has been established to demonstrate how different connecting sequences of two C_(2v)-symmetric building blocks lead to the formation of four two-dimensional(2D)COFs with distinct framework structures.To verify this concept,target synthesis was conducted to produce three COFs,whose structures were confirmed by powder X-ray diffraction and pore size distribution analysis.
基金supported by the National Natural Science Foundation of China(Nos.51902121 and 22372067)。
文摘Covalent organic frameworks(COFs)are two-(2D)or threedimensional(3D)crystalline,porous networks generated by reversible polymerization of organic building blocks[1,2].The structures and functionalities of COFs are precisely controlled via appropriately selected organic building blocks.This design imparts unique properties to COFs,including exceptional structural stability,tunable pore structure,and surface chemical activity,making them promising for gas separation,catalysis,optoelectronics,and sensing applications.Since Yaghi et al.'s seminal report on COFs in 2005[2],these frameworks have swiftly emerged as a hotspot in the field of materials.Originally,the focus was on fabricating rigid frameworks with static structures and optoelectronic properties.However,the inherently static nature of these frameworks hinders their responsiveness to external stimuli,potentially constraining their functionality in specific applications.Hence,an increasing number of researchers are now directing their attention toward the development of dynamic COFs capable of modifying their structures in response to external stimuli[3].Specifically,dynamic 2D COFs exhibiting enhanced structural responsiveness are of particular interest due to their capability to integrate switchable geometries and porosities with semiconductor building blocks,as well as electron conjugation across COF layers and π-stacked columns,which may enable stimuli-responsive electronic and spin properties[4].
基金the National Natural Science Foundation of China(Nos.52103352,51925306 and 52120105006)National Key R&D Program of China(No.2018FYA 0305800)+3 种基金Key Research Program of Chinese Academy of Sciences(No.XDPB08-2)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB28000000)the Youth Innovation Promotion Association of Chinese Academy of Sciences(No.2022165)the Fundamental Research Funds for the Central Universities.
文摘Nonfused ring electron acceptors(NFREAs)have attracted much attention due to their concise synthetic routes and low cost.However,developing high-performance NFREAs with simple structure remains a great challenge.In this work,a simple building block(POBT)with noncovalently conformational locks(No CLs)was designed and synthesized.Single-crystal X-ray study indicated the presence of S…O NOCLs in POBT,thus enabling it to possess a coplanar conformation comparable to that of fused-ring CPT.Two novel NFREAs based on CPT and POBT were developed,namely TT-CPT and TT-POBT,respectively.Besides,TT-POBT possessed a smaller Stokes shift and a reduced reorganization energy compared with TT-CPT,indicating the introduction of S…O No CLs can enhance the molecular rigidity even if simplifying the molecular structure.As a result,the TT-POBT-based PSC device afforded an impressive power conversion efficiency of 11.15%,much higher than that of TT-CPT counterpart(7.03%),mainly resulting from the tighterπ-πstacking,improved and balanced charge transport,and more favorable film morphology.This work demonstrates the potential of the simple building block POBT with No CLs towards constructing low-cost and highperformance NFREAs.
基金supported by National Natural Science Foundation of China (50805051)Guangdong Provincial Science and Technology Project (2008B010400041)
文摘To date, the high power arc plasma technology is widely used. A next generation high power arc plasma system based on building block structure is presented. The whole arc plasma inverter system is composed of 12 paralleled units to increase the system output capability. The hierarchical control system is adopted to improve the reliability and flexibility of the high power arc plasma inverter. To ensure the reliable turn on and off of the IGBT module in each building block unit, a special pulse drive circuit is designed by using pulse transformer. The experimental result indicates that the high power arc plasma inverter system can transfer 300 kW arc plasma energy reliably with high efficiency.
基金financially supported by the National Natural Science Foundation of China(Nos.22135007,21875244 and 52073281)Jilin Scientific and Technological Development Program(No.YDZJ202101ZYTS138)。
文摘The development of donor-acceptor(D-A)type conjugated polymers depends largely on the design of novel A building blocks.Herein,we report a novel A building block based on the cyano-substituted organoboron unit(SBN-3).Compared with the most common fluorine-substituted B←N unit,SBN-3 displays a significantly downshifted LUMO energy level because of the strong electron-withdrawing ability of cyano groups.In addition,due to the greater impact of cyano substitution on LUMO than on HOMO,SBN-3 exhibits a reduced band gap,nearinfrared absorption and fluorescence properties.The D-A type conjugated polymers based on the cyano-substituted B←N unit with thiophene-based units show narrow optical band gaps of ca.1.3 e V as well as distinctive electronic structures,i.e.,delocalized LUMOs and localized HOMOs.This work thus provides not only an effective approach to design strong A units but also a new electron-deficient building block for D-A type conjugated polymers.
