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
We demonstrate an all-optical technique for in situ monitoring of strong-field ionization(SFI)dynamics.The method relies on coherent scattering of a probe pulse from a transient plasma grating(TPG)formed by two interf...We demonstrate an all-optical technique for in situ monitoring of strong-field ionization(SFI)dynamics.The method relies on coherent scattering of a probe pulse from a transient plasma grating(TPG)formed by two interfering femtosecond pulses in a gas target.The diffracted signal provides a real-time,relative measure of the ionization yield.We demonstrate the method’s sensitivity by resolving the attosecond-scale coherent control of the ionization rate.Unlike conventional diagnostics that directly measure charged particles,our ensemble-based optical method is non-invasive and particularly suited for non-vacuum environments.To demonstrate its utility,we apply the technique to investigate the relationship between ionization and terahertz(THz)generation in a two-color(ω+2ω)field.We measure a phase offset of(0.18±0.05)π between the maxima of the ionization yield and the THz emission.This result provides a quantitative benchmark for theoretical models and establishes the TPG technique as a practical tool for probing SFI dynamics in ensemble systems.展开更多
BACKGROUND Magnesium(Mg^(2+))plays a fundamental role in numerous cellular processes,including enzymatic reactions,DNA replication,oxidative stress response,and cytoskeletal dynamics.In fact,dysregulation of Mg^(2+)ho...BACKGROUND Magnesium(Mg^(2+))plays a fundamental role in numerous cellular processes,including enzymatic reactions,DNA replication,oxidative stress response,and cytoskeletal dynamics.In fact,dysregulation of Mg^(2+)homeostasis has been increasingly associated with the development and progression of cancer,particularly colorectal cancer(CRC).Transient receptor potential melastatin(TRPM)channels,especially TRPM6 and TRPM7,are essential regulators of epithelial Mg^(2+)influx.While TRPM7 promotes CRC progression,the role of TRPM6 and TRPM6/7 channels remains unclear.AIM To investigate the role of membrane-localized TRPM6 and TRPM6/7 channels in Mg^(2+)influx,spheroid(SP)formation,stemness,and migration.METHODS We used parental and SP-derived HT-29 cells at comparable passages as in vitro models.Mass spectrometry confirmed full-length sequences,phosphorylation,and methionine oxidation of TRPM6 and TRPM7.Mg^(2+)influx,total and free Mg^(2+)levels were measured by fluorescence imaging and biochemical assays.TRPM6/TRPM7 expression and markers were analyzed by western blot.Func-tional assays,including secondary SP formation and wound healing,assessed stemness and migration.Cells were treated with Mg^(2+)transport inhibitors:Co(III)hexamine,2-aminoethyl diphenylborinate(TRPM6/7 blocker),and Mesendogen(TRPM6 inhibitor).RESULTS The expression of membrane-bound TRPM6,TRPM7,and TRPM6/7 was significantly higher in SP cells than in parental cells.Mass spectrometric analysis confirmed the presence of full-length TRPM6 and TRPM7 with increased phosphorylation and oxidation in SP cells.Enhanced Mg^(2+)influx and total intracellular Mg^(2+)levels were observed in SP cells.Free ionized intracellular Mg^(2+)levels remained comparable across all experimental groups.Pharmacological inhibition of TRPM6 and TRPM6/7 significantly reduced Mg^(2+)influx,decreased total Mg^(2+)content,compromised CRC SP stability,abolished cancer stem-like properties,impaired cell migration,and downregulated pro-tumorigenic markers,including Nanog,cyclooxygenase-2,and matrix metalloproteinase-9.CONCLUSION Membrane-localized TRPM6 and TRPM6/7 channels regulate Mg^(2+)influx and promote CRC stemness,SP stability,and migration,highlighting their potential as therapeutic targets to inhibit CRC progression and metastasis.展开更多
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
We calculate the multicomponent responses of surface-hole transient electromagnetic method. The methods and models are unsuitable as geoelectric models of conductive surrounding rocks because they are based on regular...We calculate the multicomponent responses of surface-hole transient electromagnetic method. The methods and models are unsuitable as geoelectric models of conductive surrounding rocks because they are based on regular local targets. We also propose a calculation and analysis scheme based on numerical simulations of the subsurface transient electromagnetic fields. In the modeling of the electromagnetic fields, the forward modeling simulations are performed by using the finite-difference time-domain method and the discrete image method, which combines the Gaver–Stehfest inverse Laplace transform with the Prony method to solve the initial electromagnetic fields. The precision in the iterative computations is ensured by using the transmission boundary conditions. For the response analysis, we customize geoelectric models consisting of near-borehole targets and conductive wall rocks and implement forward modeling simulations. The observed electric fields are converted into induced electromotive force responses using multicomponent observation devices. By comparing the transient electric fields and multicomponent responses under different conditions, we suggest that the multicomponent-induced electromotive force responses are related to the horizontal and vertical gradient variations of the transient electric field at different times. The characteristics of the response are determined by the varying the subsurface transient electromagnetic fields, i.e., diffusion, attenuation and distortion, under different conditions as well as the electromagnetic fields at the observation positions. The calculation and analysis scheme of the response consider the surrounding rocks and the anomalous field of the local targets. It therefore can account for the geological data better than conventional transient field response analysis of local targets.展开更多
The forward modeling procedure used in this article is formulated with the volume integral equation based on the tensor Green＇s function. The electromagnetic components responses are first calculated in the frequency...The forward modeling procedure used in this article is formulated with the volume integral equation based on the tensor Green＇s function. The electromagnetic components responses are first calculated in the frequency domain and then transformed to the time domain by digital filtering. The valley and hill topography with a layered earth is stimulated by a horizontal electric dipole （HED） transmitter, which is common in field surveys, and the TEM responses are calculated at the transmitter and receivers. The topography effects on the long offset electromagnetic transient （LOTEM） responses are discussed in detail. The results show that both valley and hill topography has significant effect on the LOTEM measurement. If the HED is located in the bottom of a valley, the distortion of the observed anomalous field at distance is severe. A valley at the receiver locations show a strong effect but are localized in space and time. In general, hill-shaped topography shows smaller effects no matter where its located. When the topography is located between source and receivers, the influence is negligible. We conclude that the location of the source is much more important than the receivers and it is critical to put the transmitter in an open flat area in the field survey.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
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
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
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
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
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
BACKGROUND Noninvasive tests are crucial for the management and follow-up of patients with autoimmune hepatitis,but their validation is limited because of insufficient data.AIM To investigate the diagnostic performanc...BACKGROUND Noninvasive tests are crucial for the management and follow-up of patients with autoimmune hepatitis,but their validation is limited because of insufficient data.AIM To investigate the diagnostic performance of three fibrosis noninvasive tests[FibroTest,vibration-controlled transient elastography(VCTE),and the fibrosis-4 index(FIB-4)and two activity biomarkers(alanine aminotransferase(ALT)and ActiTest].METHODS This study enrolled 103 patients for whom liver biopsy,hepatic elastography results,and laboratory markers were available.Diagnostic performance was assessed with receiver operating characteristic(ROC)curves,the Obuchowski measure(OM),and the Bayesian latent class model.RESULTS FibroTest and VCTE outperformed FIB-4 in cases of significant fibrosis(≥F2),with areas under the ROC curve of 0.83[95%confidence interval(CI):0.73-0.90],0.86(95%CI:0.77-0.92),and 0.71(95%CI:0.60-0.80),respectively.The mean(standard error)OM values were 0.92(0.01),0.93(0.01),and 0.88(0.02)for FibroTest,VCTE,and FIB-4,respectively;FibroTest and VCTE performed comparably,and both were superior to FIB-4(P=0.03 and P=0.005).The areas under the ROC curve values for activity biomarkers were 0.86(95%CI:0.76-0.92)for ActiTest and 0.84(95%CI:0.73-0.90)for ALT(P=0.06).The OM values for ActiTest and ALT were 0.92(0.02)and 0.90(0.02),respectively(P=0.005).CONCLUSION FibroTest and VCTE outperformed FIB-4 according to the OM.FibroTest-ActiTest facilitated the evaluation of both fibrosis and activity.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
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
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 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
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 NUDT Science Foundation for Indigenous Innovation(Grant No.24-ZZCX-ZXGC-15)the National Natural Science Foundation of China(Grant Nos.12234020,12450403,and 12374263)。
文摘We demonstrate an all-optical technique for in situ monitoring of strong-field ionization(SFI)dynamics.The method relies on coherent scattering of a probe pulse from a transient plasma grating(TPG)formed by two interfering femtosecond pulses in a gas target.The diffracted signal provides a real-time,relative measure of the ionization yield.We demonstrate the method’s sensitivity by resolving the attosecond-scale coherent control of the ionization rate.Unlike conventional diagnostics that directly measure charged particles,our ensemble-based optical method is non-invasive and particularly suited for non-vacuum environments.To demonstrate its utility,we apply the technique to investigate the relationship between ionization and terahertz(THz)generation in a two-color(ω+2ω)field.We measure a phase offset of(0.18±0.05)π between the maxima of the ionization yield and the THz emission.This result provides a quantitative benchmark for theoretical models and establishes the TPG technique as a practical tool for probing SFI dynamics in ensemble systems.
基金Supported by Burapha University,Thailand Science Research and Innovation,and National Science Research and Innovation Fund,No.53/2567.
文摘BACKGROUND Magnesium(Mg^(2+))plays a fundamental role in numerous cellular processes,including enzymatic reactions,DNA replication,oxidative stress response,and cytoskeletal dynamics.In fact,dysregulation of Mg^(2+)homeostasis has been increasingly associated with the development and progression of cancer,particularly colorectal cancer(CRC).Transient receptor potential melastatin(TRPM)channels,especially TRPM6 and TRPM7,are essential regulators of epithelial Mg^(2+)influx.While TRPM7 promotes CRC progression,the role of TRPM6 and TRPM6/7 channels remains unclear.AIM To investigate the role of membrane-localized TRPM6 and TRPM6/7 channels in Mg^(2+)influx,spheroid(SP)formation,stemness,and migration.METHODS We used parental and SP-derived HT-29 cells at comparable passages as in vitro models.Mass spectrometry confirmed full-length sequences,phosphorylation,and methionine oxidation of TRPM6 and TRPM7.Mg^(2+)influx,total and free Mg^(2+)levels were measured by fluorescence imaging and biochemical assays.TRPM6/TRPM7 expression and markers were analyzed by western blot.Func-tional assays,including secondary SP formation and wound healing,assessed stemness and migration.Cells were treated with Mg^(2+)transport inhibitors:Co(III)hexamine,2-aminoethyl diphenylborinate(TRPM6/7 blocker),and Mesendogen(TRPM6 inhibitor).RESULTS The expression of membrane-bound TRPM6,TRPM7,and TRPM6/7 was significantly higher in SP cells than in parental cells.Mass spectrometric analysis confirmed the presence of full-length TRPM6 and TRPM7 with increased phosphorylation and oxidation in SP cells.Enhanced Mg^(2+)influx and total intracellular Mg^(2+)levels were observed in SP cells.Free ionized intracellular Mg^(2+)levels remained comparable across all experimental groups.Pharmacological inhibition of TRPM6 and TRPM6/7 significantly reduced Mg^(2+)influx,decreased total Mg^(2+)content,compromised CRC SP stability,abolished cancer stem-like properties,impaired cell migration,and downregulated pro-tumorigenic markers,including Nanog,cyclooxygenase-2,and matrix metalloproteinase-9.CONCLUSION Membrane-localized TRPM6 and TRPM6/7 channels regulate Mg^(2+)influx and promote CRC stemness,SP stability,and migration,highlighting their potential as therapeutic targets to inhibit CRC progression and metastasis.
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.
基金supported by the Young Scientists Fund of the National Natural Science Foundation of China(No.41304082)the China Postdoctoral Science Foundation(No.2016M590731)+2 种基金the Young Scientists Fund of the Natural Science Foundation of Hebei Province(No.D2014403011)the Program for Young Excellent Talents of Higher Education Institutions of Hebei Province(No.BJ2016046)the Geological survey project of China Geological Survey(No.1212011121197)
文摘We calculate the multicomponent responses of surface-hole transient electromagnetic method. The methods and models are unsuitable as geoelectric models of conductive surrounding rocks because they are based on regular local targets. We also propose a calculation and analysis scheme based on numerical simulations of the subsurface transient electromagnetic fields. In the modeling of the electromagnetic fields, the forward modeling simulations are performed by using the finite-difference time-domain method and the discrete image method, which combines the Gaver–Stehfest inverse Laplace transform with the Prony method to solve the initial electromagnetic fields. The precision in the iterative computations is ensured by using the transmission boundary conditions. For the response analysis, we customize geoelectric models consisting of near-borehole targets and conductive wall rocks and implement forward modeling simulations. The observed electric fields are converted into induced electromotive force responses using multicomponent observation devices. By comparing the transient electric fields and multicomponent responses under different conditions, we suggest that the multicomponent-induced electromotive force responses are related to the horizontal and vertical gradient variations of the transient electric field at different times. The characteristics of the response are determined by the varying the subsurface transient electromagnetic fields, i.e., diffusion, attenuation and distortion, under different conditions as well as the electromagnetic fields at the observation positions. The calculation and analysis scheme of the response consider the surrounding rocks and the anomalous field of the local targets. It therefore can account for the geological data better than conventional transient field response analysis of local targets.
基金supported by National Natural Science Foundation of China (Nos. 40727001, 40774073, and 40774074)the National Basic Research Programs of China (973 Program) (No. 2007CB209607)the Doctoral Program of Higher Research and Special funds (No. 20070489001)
文摘The forward modeling procedure used in this article is formulated with the volume integral equation based on the tensor Green＇s function. The electromagnetic components responses are first calculated in the frequency domain and then transformed to the time domain by digital filtering. The valley and hill topography with a layered earth is stimulated by a horizontal electric dipole （HED） transmitter, which is common in field surveys, and the TEM responses are calculated at the transmitter and receivers. The topography effects on the long offset electromagnetic transient （LOTEM） responses are discussed in detail. The results show that both valley and hill topography has significant effect on the LOTEM measurement. If the HED is located in the bottom of a valley, the distortion of the observed anomalous field at distance is severe. A valley at the receiver locations show a strong effect but are localized in space and time. In general, hill-shaped topography shows smaller effects no matter where its located. When the topography is located between source and receivers, the influence is negligible. We conclude that the location of the source is much more important than the receivers and it is critical to put the transmitter in an open flat area in the field survey.
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 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 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 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).
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.
文摘BACKGROUND Noninvasive tests are crucial for the management and follow-up of patients with autoimmune hepatitis,but their validation is limited because of insufficient data.AIM To investigate the diagnostic performance of three fibrosis noninvasive tests[FibroTest,vibration-controlled transient elastography(VCTE),and the fibrosis-4 index(FIB-4)and two activity biomarkers(alanine aminotransferase(ALT)and ActiTest].METHODS This study enrolled 103 patients for whom liver biopsy,hepatic elastography results,and laboratory markers were available.Diagnostic performance was assessed with receiver operating characteristic(ROC)curves,the Obuchowski measure(OM),and the Bayesian latent class model.RESULTS FibroTest and VCTE outperformed FIB-4 in cases of significant fibrosis(≥F2),with areas under the ROC curve of 0.83[95%confidence interval(CI):0.73-0.90],0.86(95%CI:0.77-0.92),and 0.71(95%CI:0.60-0.80),respectively.The mean(standard error)OM values were 0.92(0.01),0.93(0.01),and 0.88(0.02)for FibroTest,VCTE,and FIB-4,respectively;FibroTest and VCTE performed comparably,and both were superior to FIB-4(P=0.03 and P=0.005).The areas under the ROC curve values for activity biomarkers were 0.86(95%CI:0.76-0.92)for ActiTest and 0.84(95%CI:0.73-0.90)for ALT(P=0.06).The OM values for ActiTest and ALT were 0.92(0.02)and 0.90(0.02),respectively(P=0.005).CONCLUSION FibroTest and VCTE outperformed FIB-4 according to the OM.FibroTest-ActiTest facilitated the evaluation of both fibrosis and activity.
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"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.
