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
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
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.
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
A novel CF_3-containing building block, (Z)-ethyl 3-bromo-4,4,4-trifluoro-2-butenoate, was easily prepared from CF_3CBr_3, the former reacted with alkynes Or organozinc reagents in the presence of Pd complexes to affo...A novel CF_3-containing building block, (Z)-ethyl 3-bromo-4,4,4-trifluoro-2-butenoate, was easily prepared from CF_3CBr_3, the former reacted with alkynes Or organozinc reagents in the presence of Pd complexes to afford useful CF_3-containing intermediates in good yield.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
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
In this paper, we propose a new genetic algorithm for job-shop scheduling problems (JSP). The proposed method uses the operation-based representation, based on schema theorem and building block hypothesis, a new cro...In this paper, we propose a new genetic algorithm for job-shop scheduling problems (JSP). The proposed method uses the operation-based representation, based on schema theorem and building block hypothesis, a new crossover is proposed : By selecting short, low order highly fit schemas to genetic operator, the crossover can exchange meaningful ordering information of parents effectively and can search the global optimization. Simulation results on MT benchmark problem coded by C + + show that our genetic operators are very powerful and suitable to job-shop scheduling problems and our method outperforms the previous GA-based approaches.展开更多
In this invention, the procedure of cutting, conveying, threshing and transporting stalks are carried out by a set of conveying chains ( see figure). The axis of the main drum 2 is placed horizontally transverse (vert...In this invention, the procedure of cutting, conveying, threshing and transporting stalks are carried out by a set of conveying chains ( see figure). The axis of the main drum 2 is placed horizontally transverse (vertical to the forward direction). The upper and the lower conveying chains 8, 10 as well as cutterbar 11 are mounted in the lower part of the axial feed opening. Several star well 9 and plastic stalk-pressing rod are filled at the front of the lower conveying chain, and a spring stalk pressing assembly at the rear. The residue after threshing is discharged by star seels 18, 34. The staiks are placed near the cutterbar 11. Once the stalks are cut off by the cutterbar, they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
Highly reduced polyoxometalates(POMs) are predicted to be used as rather high energy density materials;however,it still suffers from the limited cluster species and reduction ratio.Here we demonstrate that it is possi...Highly reduced polyoxometalates(POMs) are predicted to be used as rather high energy density materials;however,it still suffers from the limited cluster species and reduction ratio.Here we demonstrate that it is possible to employ the building block strategy to generate a highly reduced polyoxomolybdate(C_(2)H_(8)N)_(14)(NH_(4))_(4)H_(14)[Mo_(48)-ⅤMo_(26)ⅥO_(202)(OH)_(12)(SO_(4))_(6)]·46H_(2)O(Mo_(74)).The fundamental Mo-based{Mo_x}(x=4,5,and 6) building blocks,which are templated by tetra-coordinated anions{MoO_(4)}or{SO_(4)},not only lay foundation for the formation of Mo_(74) featuring an unprecedented reduction ratio of 65%,but also give rise to SBBs-mediated(secondary building blocks) supramolecular dense packing interactions among the isolated Mo_(74) clusters that are favorable for proton conduction.Remarkably,high proton conductivity(2.04×10^(-2)S cm^(-1)) had been realized at 50℃ and 90% relative humidity,revealing one of the well-known POMs-based crystalline proton conducting materials.This result highlights that this building block approach possesses great potential in producing highly reduced POM systems that can achieve controllable reduced ratio and desirable properties.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
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
The development of polymerized fused-ring small molecule acceptors(FRA-PAs) has boosted the performance of all-polymer solar cells(all-PSCs).However,these FRA-PAs suffer from lengthy synthesis steps and high productio...The development of polymerized fused-ring small molecule acceptors(FRA-PAs) has boosted the performance of all-polymer solar cells(all-PSCs).However,these FRA-PAs suffer from lengthy synthesis steps and high production costs due to the high degree of synthetic complexity for fused-ring small molecule acceptors(FRAs).Furthermore,most FRA-PAs exhibit strong batch-to-batch variation,limiting further industrial applications.Herein,we designed and synthesized asymmetric non-fused electron-deficient building block TIC-Br with a simple structure(only three synthetic steps),showing a planar configuration,excellent electron affinity,and large dipole moment.A simple polymer acceptor PTIB was further developed by polymerization of TIC-Br and sensitized fluorinated-thienyl benzodithiophene(BDT-TF-Sn).PTIB exhibits a broad absorption from 300 to 800 nm,a suitable lowest unoccupied molecular orbital(LUMO) energy level of-3.86 e V,and moderate electron mobility(1.02×10^(-4)cm^(2)V^(-1)s^(-1)).When matched with PM6,the device achieved the best PCE of 10.11%with a high V_(OC) of 0.97 V,which is one of the highest among those reported all-PSCs.More importantly,PTIB exhibits a lower synthetic complexity index(SC=35.0%)and higher figure-of-merit values(FOM=29.0%) than all the reported high-performance PAs.The polymer also exhibits excellent batch-to-batch reproducibility and great potential for scale-up fabrication.This study indicates that TIC-Br is a promising building block for constructing low-cost polymer acceptors for large-scale applications in all-PSCs.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
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.
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.
基金This work was partially supported by the National Natural Science Foundation of China.
文摘A novel CF_3-containing building block, (Z)-ethyl 3-bromo-4,4,4-trifluoro-2-butenoate, was easily prepared from CF_3CBr_3, the former reacted with alkynes Or organozinc reagents in the presence of Pd complexes to afford useful CF_3-containing intermediates in good yield.
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In this paper, we propose a new genetic algorithm for job-shop scheduling problems (JSP). The proposed method uses the operation-based representation, based on schema theorem and building block hypothesis, a new crossover is proposed : By selecting short, low order highly fit schemas to genetic operator, the crossover can exchange meaningful ordering information of parents effectively and can search the global optimization. Simulation results on MT benchmark problem coded by C + + show that our genetic operators are very powerful and suitable to job-shop scheduling problems and our method outperforms the previous GA-based approaches.
文摘In this invention, the procedure of cutting, conveying, threshing and transporting stalks are carried out by a set of conveying chains ( see figure). The axis of the main drum 2 is placed horizontally transverse (vertical to the forward direction). The upper and the lower conveying chains 8, 10 as well as cutterbar 11 are mounted in the lower part of the axial feed opening. Several star well 9 and plastic stalk-pressing rod are filled at the front of the lower conveying chain, and a spring stalk pressing assembly at the rear. The residue after threshing is discharged by star seels 18, 34. The staiks are placed near the cutterbar 11. Once the stalks are cut off by the cutterbar, they
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.
基金supported by the Natural Science Foundation of Jilin Province-Free Exploration General Project(YDZJ202201ZYTS331)the National Natural Science Foundation of China(21801038)+1 种基金the Science and Technology Research Foundation of Jilin Educational Committee(JJKH20221158KJ)the Fundamental Research Funds for the Central Universities(2412022ZD002,2412022ZD009)。
文摘Highly reduced polyoxometalates(POMs) are predicted to be used as rather high energy density materials;however,it still suffers from the limited cluster species and reduction ratio.Here we demonstrate that it is possible to employ the building block strategy to generate a highly reduced polyoxomolybdate(C_(2)H_(8)N)_(14)(NH_(4))_(4)H_(14)[Mo_(48)-ⅤMo_(26)ⅥO_(202)(OH)_(12)(SO_(4))_(6)]·46H_(2)O(Mo_(74)).The fundamental Mo-based{Mo_x}(x=4,5,and 6) building blocks,which are templated by tetra-coordinated anions{MoO_(4)}or{SO_(4)},not only lay foundation for the formation of Mo_(74) featuring an unprecedented reduction ratio of 65%,but also give rise to SBBs-mediated(secondary building blocks) supramolecular dense packing interactions among the isolated Mo_(74) clusters that are favorable for proton conduction.Remarkably,high proton conductivity(2.04×10^(-2)S cm^(-1)) had been realized at 50℃ and 90% relative humidity,revealing one of the well-known POMs-based crystalline proton conducting materials.This result highlights that this building block approach possesses great potential in producing highly reduced POM systems that can achieve controllable reduced ratio and desirable properties.
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.
基金supported by the National Natural Science Foundation of China (51973146)the Shandong Provincial Natural Science Foundation (ZR2022JQ09)the Collaborative Innovation Center of Suzhou Nano Science & Technology。
文摘The development of polymerized fused-ring small molecule acceptors(FRA-PAs) has boosted the performance of all-polymer solar cells(all-PSCs).However,these FRA-PAs suffer from lengthy synthesis steps and high production costs due to the high degree of synthetic complexity for fused-ring small molecule acceptors(FRAs).Furthermore,most FRA-PAs exhibit strong batch-to-batch variation,limiting further industrial applications.Herein,we designed and synthesized asymmetric non-fused electron-deficient building block TIC-Br with a simple structure(only three synthetic steps),showing a planar configuration,excellent electron affinity,and large dipole moment.A simple polymer acceptor PTIB was further developed by polymerization of TIC-Br and sensitized fluorinated-thienyl benzodithiophene(BDT-TF-Sn).PTIB exhibits a broad absorption from 300 to 800 nm,a suitable lowest unoccupied molecular orbital(LUMO) energy level of-3.86 e V,and moderate electron mobility(1.02×10^(-4)cm^(2)V^(-1)s^(-1)).When matched with PM6,the device achieved the best PCE of 10.11%with a high V_(OC) of 0.97 V,which is one of the highest among those reported all-PSCs.More importantly,PTIB exhibits a lower synthetic complexity index(SC=35.0%)and higher figure-of-merit values(FOM=29.0%) than all the reported high-performance PAs.The polymer also exhibits excellent batch-to-batch reproducibility and great potential for scale-up fabrication.This study indicates that TIC-Br is a promising building block for constructing low-cost polymer acceptors for large-scale applications in all-PSCs.
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.