The hybridization gap in strained-layer InAs/In_(x)Ga_(1−x) Sb quantum spin Hall insulators(QSHIs)is significantly enhanced compared to binary InAs/GaSb QSHI structures,where the typical indium composition,x,ranges be...The hybridization gap in strained-layer InAs/In_(x)Ga_(1−x) Sb quantum spin Hall insulators(QSHIs)is significantly enhanced compared to binary InAs/GaSb QSHI structures,where the typical indium composition,x,ranges between 0.2 and 0.4.This enhancement prompts a critical question:to what extent can quantum wells(QWs)be strained while still preserving the fundamental QSHI phase?In this study,we demonstrate the controlled molecular beam epitaxial growth of highly strained-layer QWs with an indium composition of x=0.5.These structures possess a substantial compressive strain within the In_(0.5)Ga_(0.5)Sb QW.Detailed crystal structure analyses confirm the exceptional quality of the resulting epitaxial films,indicating coherent lattice structures and the absence of visible dislocations.Transport measurements further reveal that the QSHI phase in InAs/In_(0.5)Ga_(0.5)Sb QWs is robust and protected by time-reversal symmetry.Notably,the edge states in these systems exhibit giant magnetoresistance when subjected to a modest perpendicular magnetic field.This behavior is in agreement with the𝑍2 topological property predicted by the Bernevig–Hughes–Zhang model,confirming the preservation of topologically protected edge transport in the presence of enhanced bulk strain.展开更多
The hybridization between oxygen 2p and transition-metal 3d states largely determines the electronic structure near the Fermi level and related functionalities of transition-metal oxides(TMOs).Considerable efforts hav...The hybridization between oxygen 2p and transition-metal 3d states largely determines the electronic structure near the Fermi level and related functionalities of transition-metal oxides(TMOs).Considerable efforts have been made to manipulate the p-d hybridization in TMOs by tailoring the spatial orbital overlap via structural engineering.Here,we demonstrate enhanced p-d hybridization in Ba^(2+)-doped LaNiO_(3)epitaxial films by simultaneously modifying both the spatial and energetic overlaps between the O-2p and Ni-3d orbitals.Combining x-ray absorption spectroscopy and firstprinciples calculations,we reveal that the enhanced hybridization stems from the synergistic effects of a reduced chargetransfer energy due to hole injection and an increased spatial orbital overlap due to straightening of Ni-O-Ni bonds.We further show that the enhanced p-d hybridization can be utilized to promote the oxygen evolution activity of LaNiO_(3).This work sheds new insights into the fine-tuning of the electronic structures of TMOs for enhanced functionalities.展开更多
Defect engineering significantly enhances electrocatalytic performance by modulating electronic structures and interfacial coordination,yet the dynamic correlation between defect evolution and catalytic activity durin...Defect engineering significantly enhances electrocatalytic performance by modulating electronic structures and interfacial coordination,yet the dynamic correlation between defect evolution and catalytic activity during reactions remains unclear.Herein,density functional theory(DFT)calculations first reveal the modulation of sulfur vacancy concentrations on Co_(9)S_(8)electronic structures,predicting that optimized vacancy concentrations enable highly efficient electrocatalytic water splitting.Experimentally fabricated Co_(9)S_(8)with appropriate sulfur vacancies exhibits superior bifunctional activity(HER:164 mV@_(η10);OER:297 mV@_(η100)).The MCS-assembled overall water splitting system demonstrates stable operation at 1.57 V(10 mA cm^(−2))for over 60 h.Experimental studies illustrate that sulfur vacancies preferentially adsorb OH^(−)during reactions,inducing the formation of CoOOH active phases.DFT analysis further indicates that OH^(−)adsorption weakens d-p orbital hybridization,optimizing hydrogen/oxygen intermediate adsorption energy barriers and ultimately enhancing catalytic performance.This work establishes novel paradigms for systematic development of catalysts through synergistic analysis of defect dynamics,electronic structures and catalytic performance.展开更多
Hybridization is a driving force in ecological transitions and speciation,yet direct evidence linking it to adaptive differentiation in natural systems remains limited.This study evaluates the role of hybridization in...Hybridization is a driving force in ecological transitions and speciation,yet direct evidence linking it to adaptive differentiation in natural systems remains limited.This study evaluates the role of hybridization in the speciation of Pinus densata,a keystone forest species on the southeastern Tibetan Plateau.By creating artificialinterspecificF1s and a long-term common garden experiment on the plateau,we provide in situ assessments on 44 growth and physiological traits across four seasons,along with RNA sequencing.We found significantphenotypic divergence between P.densata and its putative parental species P.tabuliformis and P.yunnanensis,with P.densata demonstrating superior growth and dynamic balance between photosynthesis and photoprotection.The F1s closely resembled P.densata in most traits.Gene expression revealed 19%–10%of 34,000 examined genes as differentially expressed in P.densata and F1s relative to mid-parent expression values.Both additive(4%)and non-additive gene actions(5%–6%in F1s,10%–12%in P.densata)were common,while transgressive expression occurred more frequently in the stabilized natural hybrids,illustrating transcriptomic reprogramming brought by hybridization and further divergence by natural selection.We provide compelling evidence for hybridization-derived phenotypic divergence at both physiological and gene expression levels that could have contributed to the adaptation of P.densata to high plateau habitat where both parental species have low fitness.The altered physiology and gene expression in hybrids serve both as a substrate for novel ecological adaptation and as a mechanism for the initiation of reproductive isolation.展开更多
Layered double hydroxides(LDHs)are potential cathode materials for aqueous magnesium-ion batteries(AMIBs).However,the low capacity and sluggish kinetics significantly limit their electrochemical performance in AMIBs.H...Layered double hydroxides(LDHs)are potential cathode materials for aqueous magnesium-ion batteries(AMIBs).However,the low capacity and sluggish kinetics significantly limit their electrochemical performance in AMIBs.Herein,we find that oxygen vacancies can significantly boost the capacity,electrochemical kinetics,and structure stability of LDHs.The corresponding structure-performance relationship and energy storage mechanism are elaborated through exhaustive in/ex-situ experimental characterizations and density functional theory(DFT)calculations.Specially,in-situ Raman and DFT calculations reveal that oxygen vacancies elevate orbital energy of O 2p and electron density of O atoms,thereby enhancing the orbital hybridization of O 2p with Ni/Co 3d.This facilitates electron transfer between O and adjacent Ni/Co atoms and improves the covalency of Ni–O and Co–O bonds,which activates Ni/Co atoms to release more capacity and stabilizes the Ov-NiCo-LDH structure.Moreover,the distribution of relaxation times(DRT)and molecular dynamics(MD)simulations disclose that the enhanced d-p orbital hybridization optimizes the electronic structure of Ov-NiCo-LDH,which distinctly reduces the diffusion energy barriers of Mg^(2+)and improves the charge transfer kinetics of Ov-NiCo-LDH.Consequently,the assembled Ov-NiCo-LDH//active carbon(AC)and Ov-NiCo-LDH//perylenediimide(PTCDI)AMIBs can both deliver high specific discharge capacity(182.7 and 59.4 mAh g^(−1)at 0.5 A g^(−1),respectively)and long-term cycling stability(85.4%and 89.0%of capacity retentions after 2500 and 2400 cycles at 1.0 A g^(−1),respectively).In addition,the practical prospects for Ov-NiCo-LDH-based AMIBs have been demonstrated in different application scenarios.This work not only provides an effective strategy for obtaining high-performance cathodes of AMIBs,but also fundamentally elucidates the inherent mechanisms.展开更多
Asymmetric single-atom catalysts(ASACs)have attracted much attention owing to their excellent catalytic properties.However,the relationship between asymmetric coordination and the spin states of metal sites remains un...Asymmetric single-atom catalysts(ASACs)have attracted much attention owing to their excellent catalytic properties.However,the relationship between asymmetric coordination and the spin states of metal sites remains unclear.Additionally,the modulation of reactive oxygen species in Fenton-like reactions remains challenging.Herein,a novel strategy is reported for the rational design of highly loaded Co ASACs(CoN_(1)C_(2)/C_(2)N)immobilized on three-dimensional flower-like C_(2)N using an in situ-generated carbon defect method.In particular,the asymmetrically tricoordinated CoN_(1)C_(2)/C_(2)N exhibited excellent catalytic activity for sulfachloropyridazine degradation,with a turnover frequency of 36.8 min^(–1).Experimental results and theoretical calculations revealed that the electron spin state of the Co-active sites was transferred from the low-spin configuration(t_(2g)^(6)e_(g)^(1))to the high-spin configuration(t_(2g)^(5)e_(g)^(2))owing to asymmetric coordination.The high-spin Co 3d orbital in CoN_(1)C_(2)/C_(2)N possessed more unpaired electrons and therefore,had a strong ability to gain electrons from the O 2p orbitals of HSO_(5)^(–),boosting d-p orbital hybridization.More importantly,the spin-electron filling in theσ^(*)orbital of high-spin Co 3d−O 2p accelerated the desorption of^(*)SO_(5)•^(−),which acted as a rate-limiting step in the reaction,thus facilitating more^(1)O_(2)generation.This study provides an innovative synthetic route for practical ASACs and clarifies the critical relationship between structure and spin state,paving the way for advancements in environmental remediation and energy conversion applications.展开更多
The biological species concept defines species as groups of actually or potentially interbreeding natural populations that are reproductively isolated from other such groups(Mayr,1942).Reproductive isolation,whether p...The biological species concept defines species as groups of actually or potentially interbreeding natural populations that are reproductively isolated from other such groups(Mayr,1942).Reproductive isolation,whether prezygotic or postzygotic,plays a central role in maintaining species boundaries.However,hybridization between closely related taxa can challenge these boundaries and provide insight into speciation,gene flow,and evolutionary processes(Coyne and Orr,2004).展开更多
Introduction Early cancer detection represents a critical evolution in healthcare,addressing a significant pain point in cancer treatment:the tendency for diagnoses to occur at advanced stages.Traditionally,many cance...Introduction Early cancer detection represents a critical evolution in healthcare,addressing a significant pain point in cancer treatment:the tendency for diagnoses to occur at advanced stages.Traditionally,many cancers are not identified until they have progressed to late stages,where treatment options become limited,less effective,and more costly.This late detection results in poorer prognoses,higher mortality rates,and increased healthcare costs.Without early detection tools like Fluorescence In Situ Hybridization(FISH),these challenges persist,leaving patients with fewer opportunities for successful outcomes.展开更多
Photocatalytic hydrogen(H_(2))production using solar energy is a cutting-edge green technology that holds great potential for addressing the urgent fuel and environmental crises[1–3].To achieve high-efficiency H_(2) ...Photocatalytic hydrogen(H_(2))production using solar energy is a cutting-edge green technology that holds great potential for addressing the urgent fuel and environmental crises[1–3].To achieve high-efficiency H_(2) production,cocatalyst modification is commonly employed to provide active sites for the hydrogen evolution reaction(HER)[4,5].In this context,the kinetics of hydrogen adsorption and desorption at these active sites play a crucial role in enhancing overall photocatalytic H_(2) production efficiency.However,the H adsorption/desorption kinetics often exhibit a trade-off,presenting a significant challenge in achieving an optimal equilibrium between Hads and Hdes in many cocatalyst systems.Therefore,fine-tuning the active sites to optimize the H_(2) evolution kinetics is essential for improving photocatalytic activity[6].展开更多
In this study,an inverse design framework was established to find lightweight honeycomb structures(HCSs)with high impact resistance.The hybrid HCS,composed of re-entrant(RE)and elliptical annular re-entrant(EARE)honey...In this study,an inverse design framework was established to find lightweight honeycomb structures(HCSs)with high impact resistance.The hybrid HCS,composed of re-entrant(RE)and elliptical annular re-entrant(EARE)honeycomb cells,was created by constructing arrangement matrices to achieve structural lightweight.The machine learning(ML)framework consisted of a neural network(NN)forward regression model for predicting impact resistance and a multi-objective optimization algorithm for generating high-performance designs.The surrogate of the local design space was initially realized by establishing the NN in the small sample dataset,and the active learning strategy was used to continuously extended the local optimal design until the model converged in the global space.The results indicated that the active learning strategy significantly improved the inference capability of the NN model in unknown design domains.By guiding the iteration direction of the optimization algorithm,lightweight designs with high impact resistance were identified.The energy absorption capacity of the optimal design reached 94.98%of the EARE honeycomb,while the initial peak stress and mass decreased by 28.85%and 19.91%,respectively.Furthermore,Shapley Additive Explanations(SHAP)for global explanation of the NN indicated a strong correlation between the arrangement mode of HCS and its impact resistance.By reducing the stiffness of the cells at the top boundary of the structure,the initial impact damage sustained by the structure can be significantly improved.Overall,this study proposed a general lightweight design method for array structures under impact loads,which is beneficial for the widespread application of honeycomb-based protective structures.展开更多
In order to address environmental pollution and resource depletion caused by traditional power generation,this paper proposes an adaptive iterative dynamic-balance optimization algorithm that integrates the Improved D...In order to address environmental pollution and resource depletion caused by traditional power generation,this paper proposes an adaptive iterative dynamic-balance optimization algorithm that integrates the Improved Dung Beetle Optimizer(IDBO)with VariationalMode Decomposition(VMD).The IDBO-VMD method is designed to enhance the accuracy and efficiency of wind-speed time-series decomposition and to effectively smooth photovoltaic power fluctuations.This study innovatively improves the traditional variational mode decomposition(VMD)algorithm,and significantly improves the accuracy and adaptive ability of signal decomposition by IDBO selfoptimization of key parameters K and a.On this basis,Fourier transform technology is used to define the boundary point between high frequency and low frequency signals,and a targeted energy distribution strategy is proposed:high frequency fluctuations are allocated to supercapacitors to quickly respond to transient power fluctuations;Lowfrequency components are distributed to lead-carbon batteries,optimizing long-term energy storage and scheduling efficiency.This strategy effectively improves the response speed and stability of the energy storage system.The experimental results demonstrate that the IDBO-VMD algorithm markedly outperforms traditional methods in both decomposition accuracy and computational efficiency.Specifically,it effectively reduces the charge–discharge frequency of the battery,prolongs battery life,and optimizes the operating ranges of the state-of-charge(SOC)for both leadcarbon batteries and supercapacitors.In addition,the energy management strategy based on the algorithm not only improves the overall energy utilization efficiency of the system,but also shows excellent performance in the dynamic management and intelligent scheduling of renewable energy generation.展开更多
Carbon superstructures with multiscale hierarchies and functional attributes represent an appealing cathode candidate for zinc hybrid capacitors,but their tailor-made design to optimize the capacitive activity remains...Carbon superstructures with multiscale hierarchies and functional attributes represent an appealing cathode candidate for zinc hybrid capacitors,but their tailor-made design to optimize the capacitive activity remains a confusing topic.Here we develop a hydrogen-bond-oriented interfacial super-assembly strategy to custom-tailor nanosheet-intertwined spherical carbon superstructures(SCSs)for Zn-ion storage with double-high capacitive activity and durability.Tetrachlorobenzoquinone(H-bond acceptor)and dimethylbenzidine(H-bond donator)can interact to form organic nanosheet modules,which are sequentially assembled,orientally compacted and densified into well-orchestrated superstructures through multiple H-bonds(N-H···O).Featured with rich surface-active heterodiatomic motifs,more exposed nanoporous channels,and successive charge migration paths,SCSs cathode promises high accessibility of built-in zincophilic sites and rapid ion diffusion with low energy barriers(3.3Ωs-0.5).Consequently,the assembled Zn||SCSs capacitor harvests all-round improvement in Zn-ion storage metrics,including high energy density(166 Wh kg-1),high-rate performance(172 m Ah g^(-1)at 20 A g^(-1)),and long-lasting cycling lifespan(95.5%capacity retention after 500,000 cycles).An opposite chargecarrier storage mechanism is rationalized for SCSs cathode to maximize spatial capacitive charge storage,involving high-kinetics physical Zn^(2+)/CF_(3)SO_(3)-adsorption and chemical Zn^(2+)redox with carbonyl/pyridine groups.This work gives insights into H-bond-guided interfacial superassembly design of superstructural carbons toward advanced energy storage.展开更多
Multi-label feature selection(MFS)is a crucial dimensionality reduction technique aimed at identifying informative features associated with multiple labels.However,traditional centralized methods face significant chal...Multi-label feature selection(MFS)is a crucial dimensionality reduction technique aimed at identifying informative features associated with multiple labels.However,traditional centralized methods face significant challenges in privacy-sensitive and distributed settings,often neglecting label dependencies and suffering from low computational efficiency.To address these issues,we introduce a novel framework,Fed-MFSDHBCPSO—federated MFS via dual-layer hybrid breeding cooperative particle swarm optimization algorithm with manifold and sparsity regularization(DHBCPSO-MSR).Leveraging the federated learning paradigm,Fed-MFSDHBCPSO allows clients to perform local feature selection(FS)using DHBCPSO-MSR.Locally selected feature subsets are encrypted with differential privacy(DP)and transmitted to a central server,where they are securely aggregated and refined through secure multi-party computation(SMPC)until global convergence is achieved.Within each client,DHBCPSO-MSR employs a dual-layer FS strategy.The inner layer constructs sample and label similarity graphs,generates Laplacian matrices to capture the manifold structure between samples and labels,and applies L2,1-norm regularization to sparsify the feature subset,yielding an optimized feature weight matrix.The outer layer uses a hybrid breeding cooperative particle swarm optimization algorithm to further refine the feature weight matrix and identify the optimal feature subset.The updated weight matrix is then fed back to the inner layer for further optimization.Comprehensive experiments on multiple real-world multi-label datasets demonstrate that Fed-MFSDHBCPSO consistently outperforms both centralized and federated baseline methods across several key evaluation metrics.展开更多
To enhance power flow regulation in scenarios involving large-scale renewable energy transmission via high-voltage direct current(HVDC)links and multi-infeed DC systems in load-center regions,this paper proposes a hyb...To enhance power flow regulation in scenarios involving large-scale renewable energy transmission via high-voltage direct current(HVDC)links and multi-infeed DC systems in load-center regions,this paper proposes a hybrid modular multilevel converter–capacitor-commutated line-commutated converter(MMC-CLCC)HVDC transmission system and its corresponding control strategy.First,the system topology is constructed,and a submodule configuration method for the MMC—combining full-bridge submodules(FBSMs)and half-bridge submodules(HBSMs)—is proposed to enable direct power flow reversal.Second,a hierarchical control strategy is introduced,includingMMCvoltage control,CLCC current control,and a coordinationmechanism,along with the derivation of the hybrid system’s power flow reversal characteristics.Third,leveraging the CLCC’s fast current regulation and theMMC’s negative voltage control capability,a coordinated power flow reversal control strategy is developed.Finally,an 800 kV MMC-CLCC hybrid HVDC system is modeled in PSCAD/EMTDC to validate the power flow reversal performance under a high proportion of full-bridge submodule configuration.Results demonstrate that the proposed control strategy enables rapid(1-s transition)and smooth switching of bidirectional power flow without modifying the structure of primary equipment:the transient fluctuation ofDC voltage from the rated value(UdcN)to themaximumreverse voltage(-kUdcN)is less than 5%;the DC current strictly follows the preset characteristic curve with a deviation of≤3%;the active power reverses continuously,and the system maintains stable operation throughout the reversal process.展开更多
The intergeneric hybridization between Brassica napus L. cv. oro and Matthiola incana (L.) R. Br. was carried out to study the phytogenetic peculiarities of the hybrid plants. In order to improve the oil quality of ra...The intergeneric hybridization between Brassica napus L. cv. oro and Matthiola incana (L.) R. Br. was carried out to study the phytogenetic peculiarities of the hybrid plants. In order to improve the oil quality of rape seed, ovaries of B. napus pollinated with pollen of M. incana, were cut off and inoculated onto MS media supplemented with various plant hormones at the 7th day after pollination. Two mature embryos were obtained from 750 pollinated ovaries cultured in vitro. The percentage of seed set was 0.26%. The mature embryos were transferred onto the MS media supplemented with 2.0 mg/L 6-BA + 0.1 mg/L NAA, and a compound bud was produced later. The compound bud was then cut into a number of single buds, which were transferred onto fresh media. Twenty-two plantlets in vitro were developed from the above single buds. The hybrid plants (F-1) were basically intermediate between the two parents in many,characters with a few showing hybrid vigor. The fertility of hybrid plants (F-1) was poor. Cytological studies revealed that the hybrid plants (F-1) were mixoploid. in nature. The chromosome number of many somatic cells was 2n = 26, which was the sum of the chromosome number of the two parents. The chromosome number of other somatic cells was 2n = 38, similar to that of B. napus. The hybrid offspring (F-2) from the selfed hybrid plants (F-1) showed polymorphism. Among the hybrid offspring (F-2) some were nearly matroclinous and fertile, similar to B. napus. some others were intermediate between the two parents and less fertile, and a few were poorly developed and nearly infertile. From the hybrid offspring a few plants with improved seed-oil quality were obtained.展开更多
To investigate the expression profile of maize genes induced by submergence, a subtracted cDNA library of maize seedling roots was constructed using suppression subtractive hybridization (SSH). The cDNA of maize seedl...To investigate the expression profile of maize genes induced by submergence, a subtracted cDNA library of maize seedling roots was constructed using suppression subtractive hybridization (SSH). The cDNA of maize seedling roots treated with submergence (ST) was used as tester and what from untreated roots (UT) as driver. Products of the secondary PCR from the forward subtraction were cloned into T/A vector and transferred into Escherichia coli strain JM10B by electroporation. Four hundred and eight randomly chosen transformants carrying cDNA fragments were screened with PCR-Select Deferential Screening Kit. One hundred and eighty-four cDNA clones were identified as, submergence specifically induced or highly expressed. After sequencing and removing redundant cDNAs, we got 95 submergence-induced cDNA clones. Of the 95 cDNA clones, 68 contain the regions with 60%-90% identity to their homolog in GenBank, 21 are expected to be novel genes, only 6 correspond to the published maize sequences.展开更多
The technique of producing doublehaploid of wheat by distant hybridization between wheat and maize has characterized with better inducing effect, shorter in- ducing period, easy operation, and so on. At present, it is...The technique of producing doublehaploid of wheat by distant hybridization between wheat and maize has characterized with better inducing effect, shorter in- ducing period, easy operation, and so on. At present, it is the most efficient and has great potential of application in breeding of wheat. This article reviewed princi- ple and production process of the technique, research situation of the three key in- dicators of the technology（embryo rate, seedling rate and success rate of doubling）in recent years, and application of the technology in breeding, genetics, germplasm improvement of wheat. At last, both the achievements and the direction of further improvement and development of the technology in our program were discussed.展开更多
To understand the inter-hybridization between Cucumis ssp.plants,we used 150 melon varieties as female parents to cross with Cucumis metuliferus and Cucumis anguria.Only melon accessions V2 and V129 set fruits,but see...To understand the inter-hybridization between Cucumis ssp.plants,we used 150 melon varieties as female parents to cross with Cucumis metuliferus and Cucumis anguria.Only melon accessions V2 and V129 set fruits,but seeds from fruits V2（V129）×C.metuliferus were abortive.A few of seeds from the bottom of fruit V2（V129）×C.anguria were fertile.Sequence-related amplified polymorphism（SRAP）molecular markers were used to analyze the progenies of inter-specific hybridization between C.anguria and melon V129.One pair primer（E14/M2）was found effective in amplification on male parent characteristic bands from the hybrids,suggesting that some DNA exchange had happened between C.anguria and melon V129.This study provided data for analyzing the mechanism of inter-hybridization between Cucumis plants.展开更多
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences (Grant Nos.XDB28000000 and XDB0460000)the Quantum Science and Technology-National Science and Technology Major Project (Grant No.2021ZD0302600)the National Key Research and Development Program of China(Grant No.2024YFA1409002)。
文摘The hybridization gap in strained-layer InAs/In_(x)Ga_(1−x) Sb quantum spin Hall insulators(QSHIs)is significantly enhanced compared to binary InAs/GaSb QSHI structures,where the typical indium composition,x,ranges between 0.2 and 0.4.This enhancement prompts a critical question:to what extent can quantum wells(QWs)be strained while still preserving the fundamental QSHI phase?In this study,we demonstrate the controlled molecular beam epitaxial growth of highly strained-layer QWs with an indium composition of x=0.5.These structures possess a substantial compressive strain within the In_(0.5)Ga_(0.5)Sb QW.Detailed crystal structure analyses confirm the exceptional quality of the resulting epitaxial films,indicating coherent lattice structures and the absence of visible dislocations.Transport measurements further reveal that the QSHI phase in InAs/In_(0.5)Ga_(0.5)Sb QWs is robust and protected by time-reversal symmetry.Notably,the edge states in these systems exhibit giant magnetoresistance when subjected to a modest perpendicular magnetic field.This behavior is in agreement with the𝑍2 topological property predicted by the Bernevig–Hughes–Zhang model,confirming the preservation of topologically protected edge transport in the presence of enhanced bulk strain.
基金supported by the National Key R&D Program of China(Grant No.2022YFA1402902)the National Natural Science Foundation of China(Grant Nos.12374179,12074119,12374145,051B22001,12104157,12134003,and 12304218)the Shanghai Pujiang Program(Grant No.23PJ1402200).
文摘The hybridization between oxygen 2p and transition-metal 3d states largely determines the electronic structure near the Fermi level and related functionalities of transition-metal oxides(TMOs).Considerable efforts have been made to manipulate the p-d hybridization in TMOs by tailoring the spatial orbital overlap via structural engineering.Here,we demonstrate enhanced p-d hybridization in Ba^(2+)-doped LaNiO_(3)epitaxial films by simultaneously modifying both the spatial and energetic overlaps between the O-2p and Ni-3d orbitals.Combining x-ray absorption spectroscopy and firstprinciples calculations,we reveal that the enhanced hybridization stems from the synergistic effects of a reduced chargetransfer energy due to hole injection and an increased spatial orbital overlap due to straightening of Ni-O-Ni bonds.We further show that the enhanced p-d hybridization can be utilized to promote the oxygen evolution activity of LaNiO_(3).This work sheds new insights into the fine-tuning of the electronic structures of TMOs for enhanced functionalities.
基金financially supported by National Natural Science Foundation of China(No.52473327,51572295,21273285 and 21003157)National Key R&D Program of China(No.2021YFA1501300,2019YFC1907602).
文摘Defect engineering significantly enhances electrocatalytic performance by modulating electronic structures and interfacial coordination,yet the dynamic correlation between defect evolution and catalytic activity during reactions remains unclear.Herein,density functional theory(DFT)calculations first reveal the modulation of sulfur vacancy concentrations on Co_(9)S_(8)electronic structures,predicting that optimized vacancy concentrations enable highly efficient electrocatalytic water splitting.Experimentally fabricated Co_(9)S_(8)with appropriate sulfur vacancies exhibits superior bifunctional activity(HER:164 mV@_(η10);OER:297 mV@_(η100)).The MCS-assembled overall water splitting system demonstrates stable operation at 1.57 V(10 mA cm^(−2))for over 60 h.Experimental studies illustrate that sulfur vacancies preferentially adsorb OH^(−)during reactions,inducing the formation of CoOOH active phases.DFT analysis further indicates that OH^(−)adsorption weakens d-p orbital hybridization,optimizing hydrogen/oxygen intermediate adsorption energy barriers and ultimately enhancing catalytic performance.This work establishes novel paradigms for systematic development of catalysts through synergistic analysis of defect dynamics,electronic structures and catalytic performance.
基金supported by the National Natural Science Foundation of China(32171816)T4F program Sweden.
文摘Hybridization is a driving force in ecological transitions and speciation,yet direct evidence linking it to adaptive differentiation in natural systems remains limited.This study evaluates the role of hybridization in the speciation of Pinus densata,a keystone forest species on the southeastern Tibetan Plateau.By creating artificialinterspecificF1s and a long-term common garden experiment on the plateau,we provide in situ assessments on 44 growth and physiological traits across four seasons,along with RNA sequencing.We found significantphenotypic divergence between P.densata and its putative parental species P.tabuliformis and P.yunnanensis,with P.densata demonstrating superior growth and dynamic balance between photosynthesis and photoprotection.The F1s closely resembled P.densata in most traits.Gene expression revealed 19%–10%of 34,000 examined genes as differentially expressed in P.densata and F1s relative to mid-parent expression values.Both additive(4%)and non-additive gene actions(5%–6%in F1s,10%–12%in P.densata)were common,while transgressive expression occurred more frequently in the stabilized natural hybrids,illustrating transcriptomic reprogramming brought by hybridization and further divergence by natural selection.We provide compelling evidence for hybridization-derived phenotypic divergence at both physiological and gene expression levels that could have contributed to the adaptation of P.densata to high plateau habitat where both parental species have low fitness.The altered physiology and gene expression in hybrids serve both as a substrate for novel ecological adaptation and as a mechanism for the initiation of reproductive isolation.
基金financial support of the National Natural Science Foundation of China (22379063)
文摘Layered double hydroxides(LDHs)are potential cathode materials for aqueous magnesium-ion batteries(AMIBs).However,the low capacity and sluggish kinetics significantly limit their electrochemical performance in AMIBs.Herein,we find that oxygen vacancies can significantly boost the capacity,electrochemical kinetics,and structure stability of LDHs.The corresponding structure-performance relationship and energy storage mechanism are elaborated through exhaustive in/ex-situ experimental characterizations and density functional theory(DFT)calculations.Specially,in-situ Raman and DFT calculations reveal that oxygen vacancies elevate orbital energy of O 2p and electron density of O atoms,thereby enhancing the orbital hybridization of O 2p with Ni/Co 3d.This facilitates electron transfer between O and adjacent Ni/Co atoms and improves the covalency of Ni–O and Co–O bonds,which activates Ni/Co atoms to release more capacity and stabilizes the Ov-NiCo-LDH structure.Moreover,the distribution of relaxation times(DRT)and molecular dynamics(MD)simulations disclose that the enhanced d-p orbital hybridization optimizes the electronic structure of Ov-NiCo-LDH,which distinctly reduces the diffusion energy barriers of Mg^(2+)and improves the charge transfer kinetics of Ov-NiCo-LDH.Consequently,the assembled Ov-NiCo-LDH//active carbon(AC)and Ov-NiCo-LDH//perylenediimide(PTCDI)AMIBs can both deliver high specific discharge capacity(182.7 and 59.4 mAh g^(−1)at 0.5 A g^(−1),respectively)and long-term cycling stability(85.4%and 89.0%of capacity retentions after 2500 and 2400 cycles at 1.0 A g^(−1),respectively).In addition,the practical prospects for Ov-NiCo-LDH-based AMIBs have been demonstrated in different application scenarios.This work not only provides an effective strategy for obtaining high-performance cathodes of AMIBs,but also fundamentally elucidates the inherent mechanisms.
文摘Asymmetric single-atom catalysts(ASACs)have attracted much attention owing to their excellent catalytic properties.However,the relationship between asymmetric coordination and the spin states of metal sites remains unclear.Additionally,the modulation of reactive oxygen species in Fenton-like reactions remains challenging.Herein,a novel strategy is reported for the rational design of highly loaded Co ASACs(CoN_(1)C_(2)/C_(2)N)immobilized on three-dimensional flower-like C_(2)N using an in situ-generated carbon defect method.In particular,the asymmetrically tricoordinated CoN_(1)C_(2)/C_(2)N exhibited excellent catalytic activity for sulfachloropyridazine degradation,with a turnover frequency of 36.8 min^(–1).Experimental results and theoretical calculations revealed that the electron spin state of the Co-active sites was transferred from the low-spin configuration(t_(2g)^(6)e_(g)^(1))to the high-spin configuration(t_(2g)^(5)e_(g)^(2))owing to asymmetric coordination.The high-spin Co 3d orbital in CoN_(1)C_(2)/C_(2)N possessed more unpaired electrons and therefore,had a strong ability to gain electrons from the O 2p orbitals of HSO_(5)^(–),boosting d-p orbital hybridization.More importantly,the spin-electron filling in theσ^(*)orbital of high-spin Co 3d−O 2p accelerated the desorption of^(*)SO_(5)•^(−),which acted as a rate-limiting step in the reaction,thus facilitating more^(1)O_(2)generation.This study provides an innovative synthetic route for practical ASACs and clarifies the critical relationship between structure and spin state,paving the way for advancements in environmental remediation and energy conversion applications.
基金supported by the National Natural Science Foundation of China(No.32161143024,31970405)Iran National Science Foundation,Iran-China(INSF-NSFC)joint project(No.4002006).
文摘The biological species concept defines species as groups of actually or potentially interbreeding natural populations that are reproductively isolated from other such groups(Mayr,1942).Reproductive isolation,whether prezygotic or postzygotic,plays a central role in maintaining species boundaries.However,hybridization between closely related taxa can challenge these boundaries and provide insight into speciation,gene flow,and evolutionary processes(Coyne and Orr,2004).
基金supported by Guangzhou Development Zone Science and Technology(2021GH10,2020GH10,2023GH02)the University of Macao(MYRG2022-00271-FST)The Science and Technology Development Fund(FDCT)of Macao(0032/2022/A).
文摘Introduction Early cancer detection represents a critical evolution in healthcare,addressing a significant pain point in cancer treatment:the tendency for diagnoses to occur at advanced stages.Traditionally,many cancers are not identified until they have progressed to late stages,where treatment options become limited,less effective,and more costly.This late detection results in poorer prognoses,higher mortality rates,and increased healthcare costs.Without early detection tools like Fluorescence In Situ Hybridization(FISH),these challenges persist,leaving patients with fewer opportunities for successful outcomes.
文摘Photocatalytic hydrogen(H_(2))production using solar energy is a cutting-edge green technology that holds great potential for addressing the urgent fuel and environmental crises[1–3].To achieve high-efficiency H_(2) production,cocatalyst modification is commonly employed to provide active sites for the hydrogen evolution reaction(HER)[4,5].In this context,the kinetics of hydrogen adsorption and desorption at these active sites play a crucial role in enhancing overall photocatalytic H_(2) production efficiency.However,the H adsorption/desorption kinetics often exhibit a trade-off,presenting a significant challenge in achieving an optimal equilibrium between Hads and Hdes in many cocatalyst systems.Therefore,fine-tuning the active sites to optimize the H_(2) evolution kinetics is essential for improving photocatalytic activity[6].
基金the financial supports from National Key R&D Program for Young Scientists of China(Grant No.2022YFC3080900)National Natural Science Foundation of China(Grant No.52374181)+1 种基金BIT Research and Innovation Promoting Project(Grant No.2024YCXZ017)supported by Science and Technology Innovation Program of Beijing institute of technology under Grant No.2022CX01025。
文摘In this study,an inverse design framework was established to find lightweight honeycomb structures(HCSs)with high impact resistance.The hybrid HCS,composed of re-entrant(RE)and elliptical annular re-entrant(EARE)honeycomb cells,was created by constructing arrangement matrices to achieve structural lightweight.The machine learning(ML)framework consisted of a neural network(NN)forward regression model for predicting impact resistance and a multi-objective optimization algorithm for generating high-performance designs.The surrogate of the local design space was initially realized by establishing the NN in the small sample dataset,and the active learning strategy was used to continuously extended the local optimal design until the model converged in the global space.The results indicated that the active learning strategy significantly improved the inference capability of the NN model in unknown design domains.By guiding the iteration direction of the optimization algorithm,lightweight designs with high impact resistance were identified.The energy absorption capacity of the optimal design reached 94.98%of the EARE honeycomb,while the initial peak stress and mass decreased by 28.85%and 19.91%,respectively.Furthermore,Shapley Additive Explanations(SHAP)for global explanation of the NN indicated a strong correlation between the arrangement mode of HCS and its impact resistance.By reducing the stiffness of the cells at the top boundary of the structure,the initial impact damage sustained by the structure can be significantly improved.Overall,this study proposed a general lightweight design method for array structures under impact loads,which is beneficial for the widespread application of honeycomb-based protective structures.
基金funded by the Institute of Smart Energy,Huaiyin Institute of Technology,under Grant No.HIT-ISE-2024-07.
文摘In order to address environmental pollution and resource depletion caused by traditional power generation,this paper proposes an adaptive iterative dynamic-balance optimization algorithm that integrates the Improved Dung Beetle Optimizer(IDBO)with VariationalMode Decomposition(VMD).The IDBO-VMD method is designed to enhance the accuracy and efficiency of wind-speed time-series decomposition and to effectively smooth photovoltaic power fluctuations.This study innovatively improves the traditional variational mode decomposition(VMD)algorithm,and significantly improves the accuracy and adaptive ability of signal decomposition by IDBO selfoptimization of key parameters K and a.On this basis,Fourier transform technology is used to define the boundary point between high frequency and low frequency signals,and a targeted energy distribution strategy is proposed:high frequency fluctuations are allocated to supercapacitors to quickly respond to transient power fluctuations;Lowfrequency components are distributed to lead-carbon batteries,optimizing long-term energy storage and scheduling efficiency.This strategy effectively improves the response speed and stability of the energy storage system.The experimental results demonstrate that the IDBO-VMD algorithm markedly outperforms traditional methods in both decomposition accuracy and computational efficiency.Specifically,it effectively reduces the charge–discharge frequency of the battery,prolongs battery life,and optimizes the operating ranges of the state-of-charge(SOC)for both leadcarbon batteries and supercapacitors.In addition,the energy management strategy based on the algorithm not only improves the overall energy utilization efficiency of the system,but also shows excellent performance in the dynamic management and intelligent scheduling of renewable energy generation.
基金financially supported by the National Natural Science Foundation of China(Nos.22272118,22172111,and 22309134)the Science and Technology Commission of Shanghai Municipality,China(Nos.22ZR1464100,20ZR1460300,and 19DZ2271500)+2 种基金the China Postdoctoral Science Foundation(2022M712402),the Shanghai Rising-Star Program(23YF1449200)the Zhejiang Provincial Science and Technology Project(2022C01182)the Fundamental Research Funds for the Central Universities(2023-3-YB-07)。
文摘Carbon superstructures with multiscale hierarchies and functional attributes represent an appealing cathode candidate for zinc hybrid capacitors,but their tailor-made design to optimize the capacitive activity remains a confusing topic.Here we develop a hydrogen-bond-oriented interfacial super-assembly strategy to custom-tailor nanosheet-intertwined spherical carbon superstructures(SCSs)for Zn-ion storage with double-high capacitive activity and durability.Tetrachlorobenzoquinone(H-bond acceptor)and dimethylbenzidine(H-bond donator)can interact to form organic nanosheet modules,which are sequentially assembled,orientally compacted and densified into well-orchestrated superstructures through multiple H-bonds(N-H···O).Featured with rich surface-active heterodiatomic motifs,more exposed nanoporous channels,and successive charge migration paths,SCSs cathode promises high accessibility of built-in zincophilic sites and rapid ion diffusion with low energy barriers(3.3Ωs-0.5).Consequently,the assembled Zn||SCSs capacitor harvests all-round improvement in Zn-ion storage metrics,including high energy density(166 Wh kg-1),high-rate performance(172 m Ah g^(-1)at 20 A g^(-1)),and long-lasting cycling lifespan(95.5%capacity retention after 500,000 cycles).An opposite chargecarrier storage mechanism is rationalized for SCSs cathode to maximize spatial capacitive charge storage,involving high-kinetics physical Zn^(2+)/CF_(3)SO_(3)-adsorption and chemical Zn^(2+)redox with carbonyl/pyridine groups.This work gives insights into H-bond-guided interfacial superassembly design of superstructural carbons toward advanced energy storage.
文摘Multi-label feature selection(MFS)is a crucial dimensionality reduction technique aimed at identifying informative features associated with multiple labels.However,traditional centralized methods face significant challenges in privacy-sensitive and distributed settings,often neglecting label dependencies and suffering from low computational efficiency.To address these issues,we introduce a novel framework,Fed-MFSDHBCPSO—federated MFS via dual-layer hybrid breeding cooperative particle swarm optimization algorithm with manifold and sparsity regularization(DHBCPSO-MSR).Leveraging the federated learning paradigm,Fed-MFSDHBCPSO allows clients to perform local feature selection(FS)using DHBCPSO-MSR.Locally selected feature subsets are encrypted with differential privacy(DP)and transmitted to a central server,where they are securely aggregated and refined through secure multi-party computation(SMPC)until global convergence is achieved.Within each client,DHBCPSO-MSR employs a dual-layer FS strategy.The inner layer constructs sample and label similarity graphs,generates Laplacian matrices to capture the manifold structure between samples and labels,and applies L2,1-norm regularization to sparsify the feature subset,yielding an optimized feature weight matrix.The outer layer uses a hybrid breeding cooperative particle swarm optimization algorithm to further refine the feature weight matrix and identify the optimal feature subset.The updated weight matrix is then fed back to the inner layer for further optimization.Comprehensive experiments on multiple real-world multi-label datasets demonstrate that Fed-MFSDHBCPSO consistently outperforms both centralized and federated baseline methods across several key evaluation metrics.
基金supported by Science and Technology Project of the headquarters of the State Grid Corporation of China(No.5500-202324492A-3-2-ZN).
文摘To enhance power flow regulation in scenarios involving large-scale renewable energy transmission via high-voltage direct current(HVDC)links and multi-infeed DC systems in load-center regions,this paper proposes a hybrid modular multilevel converter–capacitor-commutated line-commutated converter(MMC-CLCC)HVDC transmission system and its corresponding control strategy.First,the system topology is constructed,and a submodule configuration method for the MMC—combining full-bridge submodules(FBSMs)and half-bridge submodules(HBSMs)—is proposed to enable direct power flow reversal.Second,a hierarchical control strategy is introduced,includingMMCvoltage control,CLCC current control,and a coordinationmechanism,along with the derivation of the hybrid system’s power flow reversal characteristics.Third,leveraging the CLCC’s fast current regulation and theMMC’s negative voltage control capability,a coordinated power flow reversal control strategy is developed.Finally,an 800 kV MMC-CLCC hybrid HVDC system is modeled in PSCAD/EMTDC to validate the power flow reversal performance under a high proportion of full-bridge submodule configuration.Results demonstrate that the proposed control strategy enables rapid(1-s transition)and smooth switching of bidirectional power flow without modifying the structure of primary equipment:the transient fluctuation ofDC voltage from the rated value(UdcN)to themaximumreverse voltage(-kUdcN)is less than 5%;the DC current strictly follows the preset characteristic curve with a deviation of≤3%;the active power reverses continuously,and the system maintains stable operation throughout the reversal process.
文摘The intergeneric hybridization between Brassica napus L. cv. oro and Matthiola incana (L.) R. Br. was carried out to study the phytogenetic peculiarities of the hybrid plants. In order to improve the oil quality of rape seed, ovaries of B. napus pollinated with pollen of M. incana, were cut off and inoculated onto MS media supplemented with various plant hormones at the 7th day after pollination. Two mature embryos were obtained from 750 pollinated ovaries cultured in vitro. The percentage of seed set was 0.26%. The mature embryos were transferred onto the MS media supplemented with 2.0 mg/L 6-BA + 0.1 mg/L NAA, and a compound bud was produced later. The compound bud was then cut into a number of single buds, which were transferred onto fresh media. Twenty-two plantlets in vitro were developed from the above single buds. The hybrid plants (F-1) were basically intermediate between the two parents in many,characters with a few showing hybrid vigor. The fertility of hybrid plants (F-1) was poor. Cytological studies revealed that the hybrid plants (F-1) were mixoploid. in nature. The chromosome number of many somatic cells was 2n = 26, which was the sum of the chromosome number of the two parents. The chromosome number of other somatic cells was 2n = 38, similar to that of B. napus. The hybrid offspring (F-2) from the selfed hybrid plants (F-1) showed polymorphism. Among the hybrid offspring (F-2) some were nearly matroclinous and fertile, similar to B. napus. some others were intermediate between the two parents and less fertile, and a few were poorly developed and nearly infertile. From the hybrid offspring a few plants with improved seed-oil quality were obtained.
文摘To investigate the expression profile of maize genes induced by submergence, a subtracted cDNA library of maize seedling roots was constructed using suppression subtractive hybridization (SSH). The cDNA of maize seedling roots treated with submergence (ST) was used as tester and what from untreated roots (UT) as driver. Products of the secondary PCR from the forward subtraction were cloned into T/A vector and transferred into Escherichia coli strain JM10B by electroporation. Four hundred and eight randomly chosen transformants carrying cDNA fragments were screened with PCR-Select Deferential Screening Kit. One hundred and eighty-four cDNA clones were identified as, submergence specifically induced or highly expressed. After sequencing and removing redundant cDNAs, we got 95 submergence-induced cDNA clones. Of the 95 cDNA clones, 68 contain the regions with 60%-90% identity to their homolog in GenBank, 21 are expected to be novel genes, only 6 correspond to the published maize sequences.
文摘The technique of producing doublehaploid of wheat by distant hybridization between wheat and maize has characterized with better inducing effect, shorter in- ducing period, easy operation, and so on. At present, it is the most efficient and has great potential of application in breeding of wheat. This article reviewed princi- ple and production process of the technique, research situation of the three key in- dicators of the technology（embryo rate, seedling rate and success rate of doubling）in recent years, and application of the technology in breeding, genetics, germplasm improvement of wheat. At last, both the achievements and the direction of further improvement and development of the technology in our program were discussed.
基金Supported by Special Basic Research Fund for Central Public Research Institutes(0032011018)~~
文摘To understand the inter-hybridization between Cucumis ssp.plants,we used 150 melon varieties as female parents to cross with Cucumis metuliferus and Cucumis anguria.Only melon accessions V2 and V129 set fruits,but seeds from fruits V2（V129）×C.metuliferus were abortive.A few of seeds from the bottom of fruit V2（V129）×C.anguria were fertile.Sequence-related amplified polymorphism（SRAP）molecular markers were used to analyze the progenies of inter-specific hybridization between C.anguria and melon V129.One pair primer（E14/M2）was found effective in amplification on male parent characteristic bands from the hybrids,suggesting that some DNA exchange had happened between C.anguria and melon V129.This study provided data for analyzing the mechanism of inter-hybridization between Cucumis plants.
