As the penetration rate of distributed energy increases,the transient power angle stability problem of the virtual synchronous generator(VSG)has gradually become prominent.In view of the situation that the grid impeda...As the penetration rate of distributed energy increases,the transient power angle stability problem of the virtual synchronous generator(VSG)has gradually become prominent.In view of the situation that the grid impedance ratio(R/X)is high and affects the transient power angle stability of VSG,this paper proposes a VSG transient power angle stability control strategy based on the combination of frequency difference feedback and virtual impedance.To improve the transient power angle stability of the VSG,a virtual impedance is adopted in the voltage loop to adjust the impedance ratio R/X;and the PI control feedback of the VSG frequency difference is introduced in the reactive powervoltage link of theVSGto enhance the damping effect.Thesecond-orderVSGdynamic nonlinearmodel considering the reactive power-voltage loop is established and the influence of different proportional integral(PI)control parameters on the system balance stability is analyzed.Moreover,the impact of the impedance ratio R/X on the transient power angle stability is presented using the equal area criterion.In the simulations,during the voltage dips with the reduction of R/X from 1.6 to 0.8,Δδ_(1)is reduced from 0.194 rad to 0.072 rad,Δf_(1)is reduced from 0.170 to 0.093 Hz,which shows better transient power angle stability.Simulation results verify that compared with traditional VSG,the proposedmethod can effectively improve the transient power angle stability of the system.展开更多
OBJECTIVE:To explore if Hewei Jiangni granule(和胃降逆颗粒,HWJNG)could regulate esophageal hypersensitivity via stromal interaction molecule 1(STIM1)/transient receptor potential vanilloid subfamily member 1(TRPV1)pat...OBJECTIVE:To explore if Hewei Jiangni granule(和胃降逆颗粒,HWJNG)could regulate esophageal hypersensitivity via stromal interaction molecule 1(STIM1)/transient receptor potential vanilloid subfamily member 1(TRPV1)pathway.METHODS:Qualitative analysis of HWJNG was analysis by high performance of liquid and gas chromatography.In vivo,animal model of non-erosive reflux disease(NERD)was established by fructose intake and restraint stress.HWJNG and Omeprazole were administered by gavage to the drug intervention group.Reflux and visceral hypersensitivity were analyzed by pathological changes,PH value test,mechanical paw withdrawal threshold,thermal withdrawal latency and mast cells(MCs)degranulation.In vitro,substance P(SP)-induced P815 cells and dorsal root ganglion(DRG)cells were cocultured.Expression in both mice and cells of STIM1,TRPV1,and esophageal visceral hypersensitivity-related gastrointestinal neurochemicals were validated by enzyme linked immunosorbent assays,quantitative realtime polymerase chain reaction(qRT-PCR)and Western blot.Moreover,overexpression and small interfering RNA against STIM1 were utilized to verify of the role of HWJNG in DRG cells.RESULTS:HWJNG significantly suppressed intercellular space widening,injury of mitochondrial,MCs degranulation,mechanical allodynia and heat neuropathic sensory and increased pH value of esophageal mucosa in NERD mice.HWJNG inhibited expression of visceral hypersensitivityrelated gastrointestinal neurochemicals in esophageal mucosa and activated P815 cells,and expression of the STIM1,TRPV1 and related neurotransmitters in DRG and DRG cells.STIM1 siRNA and HWJNG both reduced P815 cells adhesion to DRGs cells and Ca2+flow into the cytoplasmic space of DRG cells.Furthermore,HWJNG could reversed STIM1 overexpression induced upregulation of TRPV1.CONCLUSION:HWJNG suppressed intercellular space widening in NERD mice,stabilized MCs and restored neuronal hyperexcitability by regulating visceral hypersensitivity via STIM1/TRPV1 pathway.展开更多
This study examines the influence of magnetic field and temperature on the transient voltage of a polycrystalline silicon radial junction solar cell in a dynamic regime under multispectral illumination. Radial junctio...This study examines the influence of magnetic field and temperature on the transient voltage of a polycrystalline silicon radial junction solar cell in a dynamic regime under multispectral illumination. Radial junction solar cells represent a major advancement in photovoltaic technologies, as they optimize light absorption and charge collection efficiency. The focus is on the impact of the magnetic field and temperature on the decay of transient voltage, which provides crucial information on recombination processes and the lifetime of minority carriers. The results reveal that the magnetic field tends to increase the transient voltage by directly affecting the transient electron density. Indeed, for B > 7 × 10−5 T, the magnetic field prolongs the relaxation time by increasing the transient voltage amplitude. Additionally, rising temperatures accelerate (ranging from 290 K to 450 K) recombination processes, thereby reducing the transient voltage, although this effect is moderated by the presence of a magnetic field. The study highlights the complex interaction between magnetic field and temperature, with significant impacts on the transient behaviour.展开更多
Background Cotton is an important crop providing the most natural fibers all over the world. The cotton genomics community has utilized whole genome sequencing data to construct an elite gene pool in which functional ...Background Cotton is an important crop providing the most natural fibers all over the world. The cotton genomics community has utilized whole genome sequencing data to construct an elite gene pool in which functional genes are related to agronomic traits. However, the functional validation of these genes is hindered by time-consuming and inefficient genetic transformation methods. Thus, establishing a transient transformation system of high efficiency is necessary for cotton genomics.Results To improve the efficiency of transient transformation, we used the protoplasts isolated from the etiolated cotyledon as recipient. The enzymatic digestion buffer comprised 1.5%(w/v) cellulase, 0.75%(w/v) macerozyme, and 1% hemicellulase, osmotically buffered with 0.4 mol·L^(-1) mannitol. After 5 h of dark incubation at 25℃, uniform cotton protoplasts were successfully isolated with a yield of 4.6 × 10^(6) protoplasts per gram(fresh weight) and 95% viability. We incubated 100 μL protoplasts(2.5 × 10^(5)·m L^(-1)) with 15 μg plasmid in the solution of 0.4 mol·L^(-1) mannitol and 40% PEG 4000 for 15 min, ultimately achieving an optimal transient transfection efficiency of 71.47%.Conclusions This transient system demonstrated effective utility in cellular biology research through successful applications in subcellular localization analyses, bimolecular fluorescence complementation(Bi FC) verification, and prime editing vector validation. Through systematic optimization, we established an efficient and expedited protoplast-based transient transformation system and successfully applied this platform to cotton functional genomics studies.展开更多
Panax Ginseng(2n=48)represents a quintessential resource in traditional Chinese medicine,renowned for its outstanding medicinal and economic benefits(Choi,2008).But the late start in analyzing the ginseng genome and t...Panax Ginseng(2n=48)represents a quintessential resource in traditional Chinese medicine,renowned for its outstanding medicinal and economic benefits(Choi,2008).But the late start in analyzing the ginseng genome and the poorly developed genetic transformation system still impede the study of ginseng gene function and the application of molecular breeding.Transient transformation has the advantages of high efficiency,low cost,and short cycle while laying the foundation for stable genetic transformation(Chen et al.,2021).In the plant transformation process,the cell wall prevents exogenous DNA or protein entry,significantly reducing the efficiency of the transformation.Protoplasts,as exposed cells wrapped by the plasma membrane,are more likely to absorb exogenous DNA,RNA,and protein.Transgenic systems of protoplasts have been established in several species and applied in many fields,such as gene function research(Gou et al.,2020),gene editing(Yang et al.,2023),and physiological or molecular mechanism research(Aoyagi,2011).For instance,Oryza sativa protoplasts were employed to screen genes involved in rice defense signaling pathways through fluorescent reporter systems,with BiFC employed to verified inter-protein interactions(He et al.,2016).A study transformed Cannabis sativa L.protoplasts with the plasmids carrying GFP and RFP genes,evaluated the efficiency under different transformation conditions by flow cytometry,and verified the induction of synthetic DR5 promoter by IAA based on the constructed system(Beard et al.,2021).展开更多
Transient electronics is a versatile tool that finds applications in various fields,including medical biology,environmental protection,and data information security.In the context of data protection,the traditional pa...Transient electronics is a versatile tool that finds applications in various fields,including medical biology,environmental protection,and data information security.In the context of data protection,the traditional passive degradation transient mode is being replaced by the active destruction mode,which features a short self-destruction time and provides greater resistance to recovery.This article presents an overview of recent progress in transient electronics,assessing the benefits and suitability of varying transient mechanisms.The article also analyses the influence of transient electronics on military security while emphasizing the advantages of implementing energetic materials.Besides,the article introduces energetic transient devices and evaluates their ability to support the autonomous operation of transient electronic devices.展开更多
A nickel-catalyzed C(sp^(2))–H alkynylation of unprotected α-substituted benzylamines is achieved by utilizing a transient directing group. The combination of a TDG with a nickel catalyst significantly improves the ...A nickel-catalyzed C(sp^(2))–H alkynylation of unprotected α-substituted benzylamines is achieved by utilizing a transient directing group. The combination of a TDG with a nickel catalyst significantly improves the reaction step and atom economy. It has been investigated that the 2,4,6-trimethylpyridine ligand was critical to achieve the optimized reactivity. This protocol provides a straightforward route for synthesizing the alkynylated free benzylamines, featuring good substrate compatibility and monoselectivity.展开更多
A pre-swirl system with a multi-chamber structure is crucial to the secondary air system of an aero engine.The airflow within the pre-swirl system(characterized by high-speed rotation and compressible flow)is complica...A pre-swirl system with a multi-chamber structure is crucial to the secondary air system of an aero engine.The airflow within the pre-swirl system(characterized by high-speed rotation and compressible flow)is complicated.During transient processes in aero engine operation,the pre-swirl system is subjected to upstream fluctuations,which is a less studied aspect.This paper delves into the unsteady flow characteristics within the pre-swirl system.We investigate the influence of different pressure-fluctuation boundary conditions,corresponding to step function,ramp function,and sine function,on the transient response characteristics of the pre-swirl system.The results indicate that the response characteristics are strongly affected by the upstream boundary conditions.An obvious overshoot phenomenon is observed in the actual temperature drop under the step and ramp function conditions.The peak time of the step function is 75%shorter compared to the ramp function.Furthermore,the flow parameters exhibit nonlinear growth during the transient process,emphasizing the need for consideration in future quasi-steady simulations.For the sine function condition,the pressure-fluctuation frequency minimally affects stable values of mass flow rate and actual temperature drop but exerts a substantial influence on the maximum deviation of actual temperature drop of the system.As the frequency increases from 100 Hz to 200 Hz,the maximum deviations for actual temperature drop change from around±13 K to±10 K.展开更多
Transient negative capacitance(NC),as an available dynamic charge effect achieved in resistor-ferroelectric capacitor(R-FEC)circuits,has triggered a series of theoretical and experimental works focusing on its physica...Transient negative capacitance(NC),as an available dynamic charge effect achieved in resistor-ferroelectric capacitor(R-FEC)circuits,has triggered a series of theoretical and experimental works focusing on its physical mechanism and device application.Here,we analytically derived the effects of different mechanical conditions on the transient NC behaviors in the R-FEC circuit based on the phenomenological model.It shows that the ferroelectric capacitor can exhibit either NC(i.e.,“single NC”and“double NC”)or positive capacitance,depending on the mechanical condition and temperature.Further numerical calculations show that the voltage drop caused by NC can be effectively controlled by temperature,applied stress,or strain.The relationship between NC voltage drop and system configurations including external resistance,dynamical coefficient of polarization,and input voltage are presented,showing diverse strategies to manipulate the NC effect.These results provide theoretical guidelines for rational design and efficient control of NC-related electronic devices.展开更多
The gold nano-plates(Au NPLs)have been extensively studied for their high quality factor as mechanical resonators.But it remains still unclear how the thickness and morphology of Au NPLs affect the hot electron diffus...The gold nano-plates(Au NPLs)have been extensively studied for their high quality factor as mechanical resonators.But it remains still unclear how the thickness and morphology of Au NPLs affect the hot electron diffusion.Here we have employed transient absorption microscopy to gain spatiotemporal imaging of the hot electron diffusion in Au NPLs.Au NPLs of varying thickness over 200 nm were synthesized.It was found that the hot electron diffusion of Au NPL excited at the boundary is obviously faster than that excited at the internal surface.And thinner Au NPLs exhibit a faster hot electron diffusion rate compared to thicker Au NPLs.Because the time constant of hot electron cooling(electron-phonon coupling)is independent of the excited position and thickness of Au NPLs,the effect of electron-phonon coupling on hot electron diffusion should be ruled out.So the hot electron diffusion rate is highly dimensionality-dependent.The quasi-one-dimensional diffusion along the boundary of nanoplate has the fastest rate of 50 cm^(2)/s,and the three-dimensional diffusion has the slowest rate of 22 cm^(2)/s.The fundamental investigation on the hot electrons transport property of Au NPLs offers a new insight for designing metal-based optoelectronic devices.展开更多
In this study,the wave motion in elastodynamics for unbounded media is modeled using an unsplit-field perfectly matched layer(PML)formulation that is solved by employing an isogeometric analysis(IGA).In the adopted co...In this study,the wave motion in elastodynamics for unbounded media is modeled using an unsplit-field perfectly matched layer(PML)formulation that is solved by employing an isogeometric analysis(IGA).In the adopted combination,the non-uniform rational B-spline(NURBS)functions are employed as basis functions.Moreover,the unbounded and artificial domains,defined in the PML method,are contained in a single patch domain.Based on the proposed scheme,the approximation of the geometry problem is set in a new scheme in which the PML’s absorbing and attenuation properties and the description of traveling waves can be represented.This includes a higher continuity and smoother approximation of the computed domain.As high-order NURBS basis functions are non-interpolatory,a penalty method is present to apply a time-dependent displacement load.The performance of the NURBS-based PML is analyzed through numerical examples for 1D and 2D domains,considering homogeneous and heterogeneous media.Further,we verify the long-time numerical stability of the present method.The developed method can be used to simulate hypothetical stratified domains commonly encountered in soil-structure interaction analyses.展开更多
The spatial constraints of aircraft have accelerated the development of multi-wing deployable mechanisms.These systems enable the rapid,sub-second deployment of multiple folding wings,which generate high-energy impact...The spatial constraints of aircraft have accelerated the development of multi-wing deployable mechanisms.These systems enable the rapid,sub-second deployment of multiple folding wings,which generate high-energy impacts upon locking-resulting in oscillations that can adversely affect aerodynamic performance.Despite their importance,the transient dynamic characteristics during deployment and locking remain insufficiently explored.This study presents an integrated dynamic model for a single-actuator,multi-wing deployable mechanism that accounts for joint clearances,component elasticity,and locking collisions.This model is used to analyze the influence of transient driving on the motion errors of multiple folding wings,the locking oscillation amplitude,and the complete stabilization time.Results indicate that as the driving force and transient deployment speed increase,all dynamic performance characteristics are notably affected.Specifically,raising the transient driving force from 3000 to 7000 N leads to a maximum increase of 60.8%in oscillation amplitude and 78.4%in stabilization time.By comparing the results of the prototype experiment with the theoretical model,it is found that the errors of the maximum locking oscillation amplitude and the complete stabilization time for the three groups of folding wings are all within the acceptable range,which verifies the theoretical model.These findings advance the theoretical understanding of transient deployment dynamics and locking oscillations in high-speed deployable mechanisms.展开更多
Small modular reactors have received widespread attention owing to their inherent safety,low investment,and flexibility.Small pressurized water reactors(SPWRs)have become important candidates for SMRs owing to their h...Small modular reactors have received widespread attention owing to their inherent safety,low investment,and flexibility.Small pressurized water reactors(SPWRs)have become important candidates for SMRs owing to their high technological maturity.Since the Fukushima accident,research on accident-tolerant fuels(ATFs),which are more resistant to serious accidents than conventional fuels,has gradually increased.This study analyzes the neutronics and thermal hydraulics of an SPWR(ACPR50S)for different ATFs,BeO+UO_(2)−SiC,BeO+UO_(2)−FeCrAl,U_(3)Si_(2)−SiC,and U_(3)Si_(2)−FeCrAl,based on a PWR fuel management code,the Bamboo-C deterministic code.In the steady state,the burnup calculations,reactivity coefficients,power and temperature distributions,and control rod reactivity worth were studied.The transients of the control rod ejection accident for the two control rods with the maximum and minimum reactivity worth were analyzed.The results showed that 5%B-10 enrichment in the wet annular burnable absorbers assembly can effectively reduce the initial reactivity and end-of-life reactivity penalty.The BeO+UO2−SiC core exhibited superior neutronic characteristics in terms of burnup and negative temperature reactivity compared with the other three cases owing to the strong moderation ability of BeO+UO_(2)and low neutron absorption of SiC.However,the U_(3)Si_(2)core had a marginally better power-flattening effect than BeO+UO_(2),and the differential worth of each control rod group was similar between different ATFs.During the transient of a control rod ejection,the changes in the fuel temperature,coolant temperature,and coolant density were similar.The maximum difference was less than 10℃ for the fuel temperature and 2℃ for the coolant temperature.展开更多
The traditional transient stability assessment(TSA)model for power systems has three disadvantages:capturing critical information during faults is difficult,aperiodic and oscillatory unstable conditions are not distin...The traditional transient stability assessment(TSA)model for power systems has three disadvantages:capturing critical information during faults is difficult,aperiodic and oscillatory unstable conditions are not distinguished,and poor generalizability is exhibited by systems with high renewable energy penetration.To address these issues,a novel ResGRU architecture for TSA is proposed in this study.First,a residual neural network(ResNet)is used for deep feature extraction of transient information.Second,a bidirectional gated recurrent unit combined with a multi-attention mechanism(BiGRU-Attention)is used to establish temporal feature dependencies.Their combination constitutes a TSA framework based on the ResGRU architecture.This method predicts three transient conditions:oscillatory instability,aperiodic instability,and stability.The model was trained offline using stochastic gradient descent with a thermal restart(SGDR)optimization algorithm in the offline training phase.This significantly improves the generalizability of the model.Finally,simulation tests on IEEE 145-bus and 39-bus systems confirmed that the proposed method has higher adaptability,accuracy,scalability,and rapidity than the conventional TSA approach.The proposed model also has superior robustness for PMU incomplete configurations,PMU noisy data,and packet loss.展开更多
A cased well model consists of a coaxial tank and casing,which houses coaxially installed transmitting and receiving coils.The transmitting coil is excited by the current produced by the transmitting circuit,and trans...A cased well model consists of a coaxial tank and casing,which houses coaxially installed transmitting and receiving coils.The transmitting coil is excited by the current produced by the transmitting circuit,and transient electromagnetic responses occur in the casing,including direct coupling and casing responses.As the range between the transmitting and receiving coils increases,direct coupling responses decay rapidly,are less than the casing response at 0.3 m,and disappear at 0.7 m.By contrast,a casing response increases rapidly and then declines slowly after reaching a peak and changes little within a specifi c range.The peak decreases slowly with range.The continuous addition of water to the tank causes slight changes in transient electromagnetic responses,so the diff erence which are subtracted from the response without water is used.Moreover,the diff erences at the time of rapid increase in response and the time of rapid decrease in response are large,forming a peak and a trough.Given that the conductivity of water in a full tank changes after the addition of salt,the diff erence in the peak is linear with the increase in the conductivity of water.This result provides an experimental basis for the design of a transient electromagnetic logging instrument that measures the conductivity of formation in cased well.展开更多
Pepper(Capsicum annuum)is one of the most important horticultural crops worldwide,which makes the development of an effective protoplast system for transient gene expression highly significant.Typically,plant protopla...Pepper(Capsicum annuum)is one of the most important horticultural crops worldwide,which makes the development of an effective protoplast system for transient gene expression highly significant.Typically,plant protoplasts are initially isolated through enzymatic digestion and then used for transient transformations mediated by polyethylene glycol(PEG).However,PEG-mediated protoplast transformation suffers from low and inconsistent efficiency,is influenced by various factors,and requires greater operator expertise.Here,we present a simple and efficient protoplast system for transient gene expression in C.annuum and Nicotiana benthamiana,without PEG-mediated transfection.This procedure involved using the first and second fully expanded true leaves of pepper and N.benthamiana plants at the six-leaf stage for Agrobacterium infiltration,followed by enzymatic digestion for protoplast isolation.The resulting protoplast transfections achieved remarkably high efficiencies,facilitating functional analyses such as subcellular localization and protein—protein interaction studies(for example,BiFC,Co-IP,and Split-LUC assays).Thus,we have demonstrated a simplified and highly efficient transient expression system for protoplasts and potential wide-ranging applications in C.annuum and N.benthamiana while bypassing PEG-mediated transfection.展开更多
In this study,the potential application of shaped charge jets as transient antennas for electromagnetic signal transmission was explored and an electromagnetic pulse radiation system with a shaped charge jet as a tran...In this study,the potential application of shaped charge jets as transient antennas for electromagnetic signal transmission was explored and an electromagnetic pulse radiation system with a shaped charge jet as a transient antenna was proposed.During the research,crucial characteristics of the transient antenna formed by a shaped charge with a 30 mm diameter,such as resonant frequency,radiation pattern,and radiation efficiency,were evaluated.The typical shaped charge jet morphology was obtained based on the simulations,in which it could insight the dynamic behavior of the shaped charge jet selected.An equivalent model experiment was employed to test the radiation efficiency,and it showed that a shorting pin loading method could increase the relative bandwidth of the jet antenna to 32.8%,and the experimental results correlate with the theoretical predictions for half-wave dipole antennas reasonably well.Additionally,variations in the diameter of the shaped charge jet were found to affect the input impedance and impedance bandwidth,while the length of the jet influenced the resonant frequency of the antenna.This suggests that altering these parameters can achieve reconfigurability of the jet antenna.展开更多
This review comprehensively explores the theory and applications of attosecond transient absorption spectroscopy(ATAS)in studying ultrafast electronic dynamics across various systems,from atoms to solids.Driven by sig...This review comprehensively explores the theory and applications of attosecond transient absorption spectroscopy(ATAS)in studying ultrafast electronic dynamics across various systems,from atoms to solids.Driven by significant advancements in ultrafast laser technology,such as generating isolated attosecond pulses,ATAS enables detailed investigations of ultrafast electronic processes with unprecedented time resolution.The article introduces the fundamental principles and historical development of ATAS.Applications of ATAS are discussed in three main domains:in atoms,where it has been used to study build-up dynamics of Autler–Townes splitting,Fano resonance,light-induced states,etc.;in molecules,where it has revealed coherent molecular wavepacket dynamics and non-adiabatic dynamics near conical intersections;and in solids,where it has been extended to investigate ultrafast charge carrier dynamics in metals,semiconductors,and insulators.The review highlights the potential of ATAS in developing ultrafast optical switches and petahertz electronics.The ability of ATAS to probe and manipulate electronic dynamics at the attosecond timescale provides a powerful tool for exploring the fundamental limits of electronic and optical processes in materials.展开更多
The traditional detailed model of the dual active bridge(DAB)power electronic transformer is characterized by the high dimensionality of its nodal admittance matrix and the need for a small simulation step size,which ...The traditional detailed model of the dual active bridge(DAB)power electronic transformer is characterized by the high dimensionality of its nodal admittance matrix and the need for a small simulation step size,which limits the speed of electromagnetic transient(EMT)simulations.To overcome these limitations,a novel EMT equivalent model based on a generalized branch-cutting method is proposed to improve the simulation efficiency of the DAB model.The DAB topology is first decomposed into two subnetworks through branch-cutting and node-tearing methods without the introduction of a one-time-step delay.Sub-sequently,the internal nodes of each sub-network are eliminated through network simplification,and the equivalent circuit for the port cascade module is derived.The model is then validated through simulations across various operating conditions.The results demonstrate that the model avoids the loss of accuracy associated with one-time-step delay,the relative error across different conditions remains below 1%,and the simulation acceleration ratios improve as the number of modules increases.展开更多
The attosecond extreme ultraviolet(XUV) pulse pump and femtosecond infrared(IR) pulse probe scheme is commonly used to study the dynamics and attosecond transient absorption(ATA) spectra of microscopic systems. In a r...The attosecond extreme ultraviolet(XUV) pulse pump and femtosecond infrared(IR) pulse probe scheme is commonly used to study the dynamics and attosecond transient absorption(ATA) spectra of microscopic systems. In a recent report [Proc. Natl. Acad. Sci. USA 121 e2307836121(2024)], we showed that shaped XUV pulses with spectral minima can significantly alter the absorption line shape of helium's 2s2p doubly excited state within a few tens of attoseconds.However, it remains unclear if similar effects could be observed in a singly excited state. In this study, we use shaped XUV pulses to excite helium's 2p singly excited state and couple the 2p and 3d states with a delayed IR pulse. Comparing these results with those from Gaussian XUV pulses, we find that the ATA spectra for the shaped XUV pulses exhibit more pronounced changes with delay, while the changes for the Gaussian pulses are gradual. We also explain these differences through population changes and analytical models. Our findings show that shaped XUV pulses can regulate the dynamics and absorption spectra of a singly excited state.展开更多
基金supported by theMajor Science and Technology Projects of China Southern Power Grid(Grant number CGYKJXM20210328).
文摘As the penetration rate of distributed energy increases,the transient power angle stability problem of the virtual synchronous generator(VSG)has gradually become prominent.In view of the situation that the grid impedance ratio(R/X)is high and affects the transient power angle stability of VSG,this paper proposes a VSG transient power angle stability control strategy based on the combination of frequency difference feedback and virtual impedance.To improve the transient power angle stability of the VSG,a virtual impedance is adopted in the voltage loop to adjust the impedance ratio R/X;and the PI control feedback of the VSG frequency difference is introduced in the reactive powervoltage link of theVSGto enhance the damping effect.Thesecond-orderVSGdynamic nonlinearmodel considering the reactive power-voltage loop is established and the influence of different proportional integral(PI)control parameters on the system balance stability is analyzed.Moreover,the impact of the impedance ratio R/X on the transient power angle stability is presented using the equal area criterion.In the simulations,during the voltage dips with the reduction of R/X from 1.6 to 0.8,Δδ_(1)is reduced from 0.194 rad to 0.072 rad,Δf_(1)is reduced from 0.170 to 0.093 Hz,which shows better transient power angle stability.Simulation results verify that compared with traditional VSG,the proposedmethod can effectively improve the transient power angle stability of the system.
基金National Natural Science Foundation of China:Study on the Molecular Mechanism of the Regulation of Crypt Goblet Cell Pyroptosis and Exocytosis to Repair Ulcerative Colitis Mucus Barrier by the Method of Clearing and Opening the Xuanfu from the Perspective of"Xuanfu-Crypt"(No.82305143),and National Natural Science Foundation of China:Exploring the Molecular Mechanism of"Hewei Jiangni Fang"Intervention in Non-erosive Reflux Disease Esophageal Hypersensitivity from the Perspective of Mas-related Gene X2/Stromal Interaction Molecule 1/Cell Adhesion Molecule 1 Pathway Regulation of Mast Cell/Dorsal Root Ganglion Communication based on the"Xinkai-Kujiang"Method(No.82374401)。
文摘OBJECTIVE:To explore if Hewei Jiangni granule(和胃降逆颗粒,HWJNG)could regulate esophageal hypersensitivity via stromal interaction molecule 1(STIM1)/transient receptor potential vanilloid subfamily member 1(TRPV1)pathway.METHODS:Qualitative analysis of HWJNG was analysis by high performance of liquid and gas chromatography.In vivo,animal model of non-erosive reflux disease(NERD)was established by fructose intake and restraint stress.HWJNG and Omeprazole were administered by gavage to the drug intervention group.Reflux and visceral hypersensitivity were analyzed by pathological changes,PH value test,mechanical paw withdrawal threshold,thermal withdrawal latency and mast cells(MCs)degranulation.In vitro,substance P(SP)-induced P815 cells and dorsal root ganglion(DRG)cells were cocultured.Expression in both mice and cells of STIM1,TRPV1,and esophageal visceral hypersensitivity-related gastrointestinal neurochemicals were validated by enzyme linked immunosorbent assays,quantitative realtime polymerase chain reaction(qRT-PCR)and Western blot.Moreover,overexpression and small interfering RNA against STIM1 were utilized to verify of the role of HWJNG in DRG cells.RESULTS:HWJNG significantly suppressed intercellular space widening,injury of mitochondrial,MCs degranulation,mechanical allodynia and heat neuropathic sensory and increased pH value of esophageal mucosa in NERD mice.HWJNG inhibited expression of visceral hypersensitivityrelated gastrointestinal neurochemicals in esophageal mucosa and activated P815 cells,and expression of the STIM1,TRPV1 and related neurotransmitters in DRG and DRG cells.STIM1 siRNA and HWJNG both reduced P815 cells adhesion to DRGs cells and Ca2+flow into the cytoplasmic space of DRG cells.Furthermore,HWJNG could reversed STIM1 overexpression induced upregulation of TRPV1.CONCLUSION:HWJNG suppressed intercellular space widening in NERD mice,stabilized MCs and restored neuronal hyperexcitability by regulating visceral hypersensitivity via STIM1/TRPV1 pathway.
文摘This study examines the influence of magnetic field and temperature on the transient voltage of a polycrystalline silicon radial junction solar cell in a dynamic regime under multispectral illumination. Radial junction solar cells represent a major advancement in photovoltaic technologies, as they optimize light absorption and charge collection efficiency. The focus is on the impact of the magnetic field and temperature on the decay of transient voltage, which provides crucial information on recombination processes and the lifetime of minority carriers. The results reveal that the magnetic field tends to increase the transient voltage by directly affecting the transient electron density. Indeed, for B > 7 × 10−5 T, the magnetic field prolongs the relaxation time by increasing the transient voltage amplitude. Additionally, rising temperatures accelerate (ranging from 290 K to 450 K) recombination processes, thereby reducing the transient voltage, although this effect is moderated by the presence of a magnetic field. The study highlights the complex interaction between magnetic field and temperature, with significant impacts on the transient behaviour.
基金supported by Biological Breeding of Early Maturing and Disease Resistant Cotton Varieties (NO.2023ZD04041)the Project of China Agriculture Research System (Grant No. CARS-15-06)+2 种基金Natural Science Foundation of Henan Province (Grant No. 232300421041 and 222300420382)National Natural Science Foundation of China (Grant No. U21 A20213)the Central Public-interest Scientific Institution Basal Research Fund (Grant No. 1610162023017 and 1610162023028)。
文摘Background Cotton is an important crop providing the most natural fibers all over the world. The cotton genomics community has utilized whole genome sequencing data to construct an elite gene pool in which functional genes are related to agronomic traits. However, the functional validation of these genes is hindered by time-consuming and inefficient genetic transformation methods. Thus, establishing a transient transformation system of high efficiency is necessary for cotton genomics.Results To improve the efficiency of transient transformation, we used the protoplasts isolated from the etiolated cotyledon as recipient. The enzymatic digestion buffer comprised 1.5%(w/v) cellulase, 0.75%(w/v) macerozyme, and 1% hemicellulase, osmotically buffered with 0.4 mol·L^(-1) mannitol. After 5 h of dark incubation at 25℃, uniform cotton protoplasts were successfully isolated with a yield of 4.6 × 10^(6) protoplasts per gram(fresh weight) and 95% viability. We incubated 100 μL protoplasts(2.5 × 10^(5)·m L^(-1)) with 15 μg plasmid in the solution of 0.4 mol·L^(-1) mannitol and 40% PEG 4000 for 15 min, ultimately achieving an optimal transient transfection efficiency of 71.47%.Conclusions This transient system demonstrated effective utility in cellular biology research through successful applications in subcellular localization analyses, bimolecular fluorescence complementation(Bi FC) verification, and prime editing vector validation. Through systematic optimization, we established an efficient and expedited protoplast-based transient transformation system and successfully applied this platform to cotton functional genomics studies.
基金supported by the Genetic analysis of important quality and traits of ginseng and basic research on molecular design breeding(Grant No.U21A20405)。
文摘Panax Ginseng(2n=48)represents a quintessential resource in traditional Chinese medicine,renowned for its outstanding medicinal and economic benefits(Choi,2008).But the late start in analyzing the ginseng genome and the poorly developed genetic transformation system still impede the study of ginseng gene function and the application of molecular breeding.Transient transformation has the advantages of high efficiency,low cost,and short cycle while laying the foundation for stable genetic transformation(Chen et al.,2021).In the plant transformation process,the cell wall prevents exogenous DNA or protein entry,significantly reducing the efficiency of the transformation.Protoplasts,as exposed cells wrapped by the plasma membrane,are more likely to absorb exogenous DNA,RNA,and protein.Transgenic systems of protoplasts have been established in several species and applied in many fields,such as gene function research(Gou et al.,2020),gene editing(Yang et al.,2023),and physiological or molecular mechanism research(Aoyagi,2011).For instance,Oryza sativa protoplasts were employed to screen genes involved in rice defense signaling pathways through fluorescent reporter systems,with BiFC employed to verified inter-protein interactions(He et al.,2016).A study transformed Cannabis sativa L.protoplasts with the plasmids carrying GFP and RFP genes,evaluated the efficiency under different transformation conditions by flow cytometry,and verified the induction of synthetic DR5 promoter by IAA based on the constructed system(Beard et al.,2021).
基金supported by the National Natural Science Foun-dation of China(Grant No.52206165)Key R&D Projects in Sichuan Province(Grant No.2022YFG0219)。
文摘Transient electronics is a versatile tool that finds applications in various fields,including medical biology,environmental protection,and data information security.In the context of data protection,the traditional passive degradation transient mode is being replaced by the active destruction mode,which features a short self-destruction time and provides greater resistance to recovery.This article presents an overview of recent progress in transient electronics,assessing the benefits and suitability of varying transient mechanisms.The article also analyses the influence of transient electronics on military security while emphasizing the advantages of implementing energetic materials.Besides,the article introduces energetic transient devices and evaluates their ability to support the autonomous operation of transient electronic devices.
基金supported financially by the Excellent Going Abroad Expert's Training Program in Hebei Province (No. 201940)the Hebei Natural Science Foundation of China (No. H2020208030)the S & T Program of Hebei (No. 22567607H) for financial support。
文摘A nickel-catalyzed C(sp^(2))–H alkynylation of unprotected α-substituted benzylamines is achieved by utilizing a transient directing group. The combination of a TDG with a nickel catalyst significantly improves the reaction step and atom economy. It has been investigated that the 2,4,6-trimethylpyridine ligand was critical to achieve the optimized reactivity. This protocol provides a straightforward route for synthesizing the alkynylated free benzylamines, featuring good substrate compatibility and monoselectivity.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDC0160000)the National Natural Science Foundation of China(No.52122603)+4 种基金the Excellence Research Group Program(No.52488101)the Shandong Provincial Natural Science Foundation of China(No.ZR2024JQ011)the Project of National Key Laboratory of Science and Technology on Advanced Light-duty Gas-turbine(No.2023-JJ-Y04)the National Science and Technology Major Project of China(No.J2019-III-0003-0046)the Taishan Scholars Program of China.
文摘A pre-swirl system with a multi-chamber structure is crucial to the secondary air system of an aero engine.The airflow within the pre-swirl system(characterized by high-speed rotation and compressible flow)is complicated.During transient processes in aero engine operation,the pre-swirl system is subjected to upstream fluctuations,which is a less studied aspect.This paper delves into the unsteady flow characteristics within the pre-swirl system.We investigate the influence of different pressure-fluctuation boundary conditions,corresponding to step function,ramp function,and sine function,on the transient response characteristics of the pre-swirl system.The results indicate that the response characteristics are strongly affected by the upstream boundary conditions.An obvious overshoot phenomenon is observed in the actual temperature drop under the step and ramp function conditions.The peak time of the step function is 75%shorter compared to the ramp function.Furthermore,the flow parameters exhibit nonlinear growth during the transient process,emphasizing the need for consideration in future quasi-steady simulations.For the sine function condition,the pressure-fluctuation frequency minimally affects stable values of mass flow rate and actual temperature drop but exerts a substantial influence on the maximum deviation of actual temperature drop of the system.As the frequency increases from 100 Hz to 200 Hz,the maximum deviations for actual temperature drop change from around±13 K to±10 K.
基金This work was supported by the National Natural Science Foundation of China(Grants Nos.12222214,12132020,12002400,and 12172386)by Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices(Grant No.2022B1212010008)+1 种基金by the National Natural Science Foundation of Guangdong Province(Grant No.2021B1515020021)by the Shenzhen Science and Techonlogy Program(Grant Nos.202206193000001 and 20220818181805001).
文摘Transient negative capacitance(NC),as an available dynamic charge effect achieved in resistor-ferroelectric capacitor(R-FEC)circuits,has triggered a series of theoretical and experimental works focusing on its physical mechanism and device application.Here,we analytically derived the effects of different mechanical conditions on the transient NC behaviors in the R-FEC circuit based on the phenomenological model.It shows that the ferroelectric capacitor can exhibit either NC(i.e.,“single NC”and“double NC”)or positive capacitance,depending on the mechanical condition and temperature.Further numerical calculations show that the voltage drop caused by NC can be effectively controlled by temperature,applied stress,or strain.The relationship between NC voltage drop and system configurations including external resistance,dynamical coefficient of polarization,and input voltage are presented,showing diverse strategies to manipulate the NC effect.These results provide theoretical guidelines for rational design and efficient control of NC-related electronic devices.
基金supported by the National Natural Science Foundation of China(No.22273006).
文摘The gold nano-plates(Au NPLs)have been extensively studied for their high quality factor as mechanical resonators.But it remains still unclear how the thickness and morphology of Au NPLs affect the hot electron diffusion.Here we have employed transient absorption microscopy to gain spatiotemporal imaging of the hot electron diffusion in Au NPLs.Au NPLs of varying thickness over 200 nm were synthesized.It was found that the hot electron diffusion of Au NPL excited at the boundary is obviously faster than that excited at the internal surface.And thinner Au NPLs exhibit a faster hot electron diffusion rate compared to thicker Au NPLs.Because the time constant of hot electron cooling(electron-phonon coupling)is independent of the excited position and thickness of Au NPLs,the effect of electron-phonon coupling on hot electron diffusion should be ruled out.So the hot electron diffusion rate is highly dimensionality-dependent.The quasi-one-dimensional diffusion along the boundary of nanoplate has the fastest rate of 50 cm^(2)/s,and the three-dimensional diffusion has the slowest rate of 22 cm^(2)/s.The fundamental investigation on the hot electrons transport property of Au NPLs offers a new insight for designing metal-based optoelectronic devices.
文摘In this study,the wave motion in elastodynamics for unbounded media is modeled using an unsplit-field perfectly matched layer(PML)formulation that is solved by employing an isogeometric analysis(IGA).In the adopted combination,the non-uniform rational B-spline(NURBS)functions are employed as basis functions.Moreover,the unbounded and artificial domains,defined in the PML method,are contained in a single patch domain.Based on the proposed scheme,the approximation of the geometry problem is set in a new scheme in which the PML’s absorbing and attenuation properties and the description of traveling waves can be represented.This includes a higher continuity and smoother approximation of the computed domain.As high-order NURBS basis functions are non-interpolatory,a penalty method is present to apply a time-dependent displacement load.The performance of the NURBS-based PML is analyzed through numerical examples for 1D and 2D domains,considering homogeneous and heterogeneous media.Further,we verify the long-time numerical stability of the present method.The developed method can be used to simulate hypothetical stratified domains commonly encountered in soil-structure interaction analyses.
基金Supported by National Natural Science Foundation of China(Grant Nos.52192634,92471202,52105013,U2341237,T2388101).
文摘The spatial constraints of aircraft have accelerated the development of multi-wing deployable mechanisms.These systems enable the rapid,sub-second deployment of multiple folding wings,which generate high-energy impacts upon locking-resulting in oscillations that can adversely affect aerodynamic performance.Despite their importance,the transient dynamic characteristics during deployment and locking remain insufficiently explored.This study presents an integrated dynamic model for a single-actuator,multi-wing deployable mechanism that accounts for joint clearances,component elasticity,and locking collisions.This model is used to analyze the influence of transient driving on the motion errors of multiple folding wings,the locking oscillation amplitude,and the complete stabilization time.Results indicate that as the driving force and transient deployment speed increase,all dynamic performance characteristics are notably affected.Specifically,raising the transient driving force from 3000 to 7000 N leads to a maximum increase of 60.8%in oscillation amplitude and 78.4%in stabilization time.By comparing the results of the prototype experiment with the theoretical model,it is found that the errors of the maximum locking oscillation amplitude and the complete stabilization time for the three groups of folding wings are all within the acceptable range,which verifies the theoretical model.These findings advance the theoretical understanding of transient deployment dynamics and locking oscillations in high-speed deployable mechanisms.
基金supported by the National Natural Science Foundation of China (No. 12205150)Natural Science Foundation of Jiangsu Province (No. BK20210304)+1 种基金China Postdoctoral Science Foundation (Nos. 2020M681594 and 2019TQ0148)Jiangsu Province Postdoctoral Science Foundation (Nos. 2020Z231)
文摘Small modular reactors have received widespread attention owing to their inherent safety,low investment,and flexibility.Small pressurized water reactors(SPWRs)have become important candidates for SMRs owing to their high technological maturity.Since the Fukushima accident,research on accident-tolerant fuels(ATFs),which are more resistant to serious accidents than conventional fuels,has gradually increased.This study analyzes the neutronics and thermal hydraulics of an SPWR(ACPR50S)for different ATFs,BeO+UO_(2)−SiC,BeO+UO_(2)−FeCrAl,U_(3)Si_(2)−SiC,and U_(3)Si_(2)−FeCrAl,based on a PWR fuel management code,the Bamboo-C deterministic code.In the steady state,the burnup calculations,reactivity coefficients,power and temperature distributions,and control rod reactivity worth were studied.The transients of the control rod ejection accident for the two control rods with the maximum and minimum reactivity worth were analyzed.The results showed that 5%B-10 enrichment in the wet annular burnable absorbers assembly can effectively reduce the initial reactivity and end-of-life reactivity penalty.The BeO+UO2−SiC core exhibited superior neutronic characteristics in terms of burnup and negative temperature reactivity compared with the other three cases owing to the strong moderation ability of BeO+UO_(2)and low neutron absorption of SiC.However,the U_(3)Si_(2)core had a marginally better power-flattening effect than BeO+UO_(2),and the differential worth of each control rod group was similar between different ATFs.During the transient of a control rod ejection,the changes in the fuel temperature,coolant temperature,and coolant density were similar.The maximum difference was less than 10℃ for the fuel temperature and 2℃ for the coolant temperature.
基金financially supported by State Key Laboratory of HVDC No.SKLHVDC-2023-KF-03.
文摘The traditional transient stability assessment(TSA)model for power systems has three disadvantages:capturing critical information during faults is difficult,aperiodic and oscillatory unstable conditions are not distinguished,and poor generalizability is exhibited by systems with high renewable energy penetration.To address these issues,a novel ResGRU architecture for TSA is proposed in this study.First,a residual neural network(ResNet)is used for deep feature extraction of transient information.Second,a bidirectional gated recurrent unit combined with a multi-attention mechanism(BiGRU-Attention)is used to establish temporal feature dependencies.Their combination constitutes a TSA framework based on the ResGRU architecture.This method predicts three transient conditions:oscillatory instability,aperiodic instability,and stability.The model was trained offline using stochastic gradient descent with a thermal restart(SGDR)optimization algorithm in the offline training phase.This significantly improves the generalizability of the model.Finally,simulation tests on IEEE 145-bus and 39-bus systems confirmed that the proposed method has higher adaptability,accuracy,scalability,and rapidity than the conventional TSA approach.The proposed model also has superior robustness for PMU incomplete configurations,PMU noisy data,and packet loss.
基金supported by the National Natural Science Foundation of China (grant nos. 42074137)。
文摘A cased well model consists of a coaxial tank and casing,which houses coaxially installed transmitting and receiving coils.The transmitting coil is excited by the current produced by the transmitting circuit,and transient electromagnetic responses occur in the casing,including direct coupling and casing responses.As the range between the transmitting and receiving coils increases,direct coupling responses decay rapidly,are less than the casing response at 0.3 m,and disappear at 0.7 m.By contrast,a casing response increases rapidly and then declines slowly after reaching a peak and changes little within a specifi c range.The peak decreases slowly with range.The continuous addition of water to the tank causes slight changes in transient electromagnetic responses,so the diff erence which are subtracted from the response without water is used.Moreover,the diff erences at the time of rapid increase in response and the time of rapid decrease in response are large,forming a peak and a trough.Given that the conductivity of water in a full tank changes after the addition of salt,the diff erence in the peak is linear with the increase in the conductivity of water.This result provides an experimental basis for the design of a transient electromagnetic logging instrument that measures the conductivity of formation in cased well.
基金supported by the National Natural Science Foundation of China(Grant Nos.32472536 and 32302526)the Natural Science Foundation of Anhui Province,China(Grant No.2208085MC64)+2 种基金the Outstanding Innovative Research Team for Molecular Enzymology and Detection in Anhui Provincial Universities(Grant No.2022AH010012)the University Synergy Innovation Program of Anhui Province(Grant No.GXXT-2022-067)the University Natural Science Research Program of Anhui Provincial Education Department(Grant No.KJ2021A0118).
文摘Pepper(Capsicum annuum)is one of the most important horticultural crops worldwide,which makes the development of an effective protoplast system for transient gene expression highly significant.Typically,plant protoplasts are initially isolated through enzymatic digestion and then used for transient transformations mediated by polyethylene glycol(PEG).However,PEG-mediated protoplast transformation suffers from low and inconsistent efficiency,is influenced by various factors,and requires greater operator expertise.Here,we present a simple and efficient protoplast system for transient gene expression in C.annuum and Nicotiana benthamiana,without PEG-mediated transfection.This procedure involved using the first and second fully expanded true leaves of pepper and N.benthamiana plants at the six-leaf stage for Agrobacterium infiltration,followed by enzymatic digestion for protoplast isolation.The resulting protoplast transfections achieved remarkably high efficiencies,facilitating functional analyses such as subcellular localization and protein—protein interaction studies(for example,BiFC,Co-IP,and Split-LUC assays).Thus,we have demonstrated a simplified and highly efficient transient expression system for protoplasts and potential wide-ranging applications in C.annuum and N.benthamiana while bypassing PEG-mediated transfection.
基金supported by the"Fundamental Research Funds for the Central Universities"(Grant No.30924010801).
文摘In this study,the potential application of shaped charge jets as transient antennas for electromagnetic signal transmission was explored and an electromagnetic pulse radiation system with a shaped charge jet as a transient antenna was proposed.During the research,crucial characteristics of the transient antenna formed by a shaped charge with a 30 mm diameter,such as resonant frequency,radiation pattern,and radiation efficiency,were evaluated.The typical shaped charge jet morphology was obtained based on the simulations,in which it could insight the dynamic behavior of the shaped charge jet selected.An equivalent model experiment was employed to test the radiation efficiency,and it showed that a shorting pin loading method could increase the relative bandwidth of the jet antenna to 32.8%,and the experimental results correlate with the theoretical predictions for half-wave dipole antennas reasonably well.Additionally,variations in the diameter of the shaped charge jet were found to affect the input impedance and impedance bandwidth,while the length of the jet influenced the resonant frequency of the antenna.This suggests that altering these parameters can achieve reconfigurability of the jet antenna.
基金Project supported by the National Natural Science Foundation of China(Grant No.12174034)。
文摘This review comprehensively explores the theory and applications of attosecond transient absorption spectroscopy(ATAS)in studying ultrafast electronic dynamics across various systems,from atoms to solids.Driven by significant advancements in ultrafast laser technology,such as generating isolated attosecond pulses,ATAS enables detailed investigations of ultrafast electronic processes with unprecedented time resolution.The article introduces the fundamental principles and historical development of ATAS.Applications of ATAS are discussed in three main domains:in atoms,where it has been used to study build-up dynamics of Autler–Townes splitting,Fano resonance,light-induced states,etc.;in molecules,where it has revealed coherent molecular wavepacket dynamics and non-adiabatic dynamics near conical intersections;and in solids,where it has been extended to investigate ultrafast charge carrier dynamics in metals,semiconductors,and insulators.The review highlights the potential of ATAS in developing ultrafast optical switches and petahertz electronics.The ability of ATAS to probe and manipulate electronic dynamics at the attosecond timescale provides a powerful tool for exploring the fundamental limits of electronic and optical processes in materials.
基金The Technology Project of State Grid Corporation of China Headquarters(No.5400-202318547A-3-2-ZN).
文摘The traditional detailed model of the dual active bridge(DAB)power electronic transformer is characterized by the high dimensionality of its nodal admittance matrix and the need for a small simulation step size,which limits the speed of electromagnetic transient(EMT)simulations.To overcome these limitations,a novel EMT equivalent model based on a generalized branch-cutting method is proposed to improve the simulation efficiency of the DAB model.The DAB topology is first decomposed into two subnetworks through branch-cutting and node-tearing methods without the introduction of a one-time-step delay.Sub-sequently,the internal nodes of each sub-network are eliminated through network simplification,and the equivalent circuit for the port cascade module is derived.The model is then validated through simulations across various operating conditions.The results demonstrate that the model avoids the loss of accuracy associated with one-time-step delay,the relative error across different conditions remains below 1%,and the simulation acceleration ratios improve as the number of modules increases.
基金Project supported by the National Natural Science Foundation of China (Grant No. 12274230)the Funding of Nanjing University of Science and Technology (Grant No. TSXK2022D005)。
文摘The attosecond extreme ultraviolet(XUV) pulse pump and femtosecond infrared(IR) pulse probe scheme is commonly used to study the dynamics and attosecond transient absorption(ATA) spectra of microscopic systems. In a recent report [Proc. Natl. Acad. Sci. USA 121 e2307836121(2024)], we showed that shaped XUV pulses with spectral minima can significantly alter the absorption line shape of helium's 2s2p doubly excited state within a few tens of attoseconds.However, it remains unclear if similar effects could be observed in a singly excited state. In this study, we use shaped XUV pulses to excite helium's 2p singly excited state and couple the 2p and 3d states with a delayed IR pulse. Comparing these results with those from Gaussian XUV pulses, we find that the ATA spectra for the shaped XUV pulses exhibit more pronounced changes with delay, while the changes for the Gaussian pulses are gradual. We also explain these differences through population changes and analytical models. Our findings show that shaped XUV pulses can regulate the dynamics and absorption spectra of a singly excited state.
