Through adding a nonlinear self-feedback term in the evolution equations of neural network, we introduced a transiently chaotic neural network model. In order to utilize the transiently chaotic dynamics mechanism in o...Through adding a nonlinear self-feedback term in the evolution equations of neural network, we introduced a transiently chaotic neural network model. In order to utilize the transiently chaotic dynamics mechanism in optimization problem efficiently, we have analyzed the dynamical procedure of the transiently chaotic neural network model and studied the function of the crucial bifurcation parameter which governs the chaotic behavior of the system. Based on the dynamical analysis of the transiently chaotic neural network model, chaotic annealing algorithm is also examined and improved. As an example, we applied chaotic annealing method to the traveling salesman problem and obtained good results.展开更多
Plants have a perception system triggered by pathogen and pest signals to initiate defense.These signals include evolutionarily conserved molecules from microbes and insects termed pathogen/herbivore-associated molecu...Plants have a perception system triggered by pathogen and pest signals to initiate defense.These signals include evolutionarily conserved molecules from microbes and insects termed pathogen/herbivore-associated molecular patterns(PAMPs/HAMPs).Here we showed that hexaacetyl-chitohexaose(HC),an oligosaccharide from chitin,a structural component in insect exoskeletons and fungi cell walls,upregulated defense-associated genes WRKY22,GST1,RAR1,EDS1,PAL1 and NPR2,and downregulated ICS1 at 1 h after HC treatment in Sun Chu Sha mandarin leaves.The effect was transient as defense gene transcriptional changes were not observed at 18 h after the treatment.Electrical penetration graph(EPG)recordings were used to study the feeding behavior of Asian citrus psyllid(ACP)following the HC treatment.ACP is the hemipteran vector of Candidatus Liberibacter asiaticus(CLas),the pathogen associated with huanglongbing(HLB).Adult ACP displayed reduced intercellular probing,reduced xylem feeding count and duration,and increased non-probing activity on HC-treated citrus compared to controls.During an 18-h recording,percentage for total duration of xylem ingestion,phloem ingestion,intercellular probing were lower,and the percentage of nonprobing behavior was higher in HC-treated leaves than in controls.In host-selection behavior studies,HC treatment did not alter the attractiveness of citrus leaves under light or dark conditions.In addition,ACP feeding on HC-treated leaves did not show differences in mortality for up to 10 day of exposure.In summary,we report that HC induced a transient defense in citrus and an inhibitory effect on ACP feeding but did not affect host selection or the insect fitness under the tested conditions.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
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
This study discusses the benefits and challenges of well monitoring for Gulong shale oil production.It examines the Unified Transient Analysis(UTA)method,which integrates rate and pressure data to monitor changes in f...This study discusses the benefits and challenges of well monitoring for Gulong shale oil production.It examines the Unified Transient Analysis(UTA)method,which integrates rate and pressure data to monitor changes in fracture surface area and production efficiency in real-time.The UTA method allows for early detection of production impairments and provides feedback to optimize drawdown pressure,enhancing production without damaging fracture conductivity.Analysis of production data from Well A in the Daqing Oilfield demonstrates the method's efficacy,particularly in managing choke size adjustments and identifying fracture conductivity degradation.Despite its benefits,challenges such as data quality,manual data analysis,and the need for automated choke management are highlighted.The study underscores the necessity of integrating intelligent monitoring technologies and automating workflows to optimize Gulong shale oil production.展开更多
Under the condition that the damping factor is between zero and one, chaotic dynamics is proved to exist in one-dimensional transiently chaotic neural networks by Li-Misiurewicz theorem. This result extends the previo...Under the condition that the damping factor is between zero and one, chaotic dynamics is proved to exist in one-dimensional transiently chaotic neural networks by Li-Misiurewicz theorem. This result extends the previous result which is done under the condition that the damping factor is zero. Because the value of damping factor affects the speed of dynamical process of transiently chaotic neural networks, this result provides more complete theoretical basis for applications. Finally, two examples by numerical simulation are given to reinforce and illustrate this result.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
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
Unstable operating conditions such as surge could cause damage to both aerodynamic performance and structural integrity of a compression system.This paper addresses the critical issue of aerodynamic instability in com...Unstable operating conditions such as surge could cause damage to both aerodynamic performance and structural integrity of a compression system.This paper addresses the critical issue of aerodynamic instability in compressor design,particularly focusing on an axial-centrifugal combined compressor,a widely used yet underexplored configuration.An experimental investigation was conducted on a three-stage axial and one-stage centrifugal compressor(3A1C),using two pipe systems and employing fast-responding transducers to capture the dynamic instability process from choke condition to deep surge.Results reveal that at the design speed,3A1C enters deep surge directly,whereas at off-design speeds,it experiences rotating stall and mild surge across a wide mass flow range.Some special instability features in the combined compressor can be found in the steady state map and dynamic process.The characteristic curve of the first axial stage keeps a positive slope during the whole mass flow range at an off-design speed.The first stage could work stably on the stall characteristic curve because the centrifugal stage has stronger pressurization and plays a dominant role in global aerodynamic instability.Besides,rotating instability occurs at the first rotor tip and disappears as the back pressure increases,which is also rarely seen in a single-axial compressor.This is also related to the strong pressurization of the centrifugal stage.The findings of this paper will contribute to the understanding of aerodynamic instabilities in combined compressors.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
High pressure can alter the properties of matter and modulate the excited-state relaxation behavior of materials without chemical intervention.In this study,high pressure was combined with steady-state absorption and ...High pressure can alter the properties of matter and modulate the excited-state relaxation behavior of materials without chemical intervention.In this study,high pressure was combined with steady-state absorption and fluorescence spectroscopy,as well as transient spectroscopy techniques,to investigate its effect on the optical properties of the stimuliresponsive material(2Z,20Z)-2,20-(1,4-phenylene)bis(3-(4-(9H-carbazol-9-yl)phenyl)acrylonitrile)(CzCNDSB).With increasing pressure,the steady-state absorption and fluorescence peaks of CzCNDSB crystals exhibit red shifts,which are fully reversible.At the same time,pressure causes the molecules to pack more closely,leading to an increase in both the number and energy of multiplet self-trapped state,while the energy of local excited state decreases.The steady-state and transient results provide information on electronic energy levels,excited-state dynamics,and other properties of CzCNDSB,which show strong pressure dependence.These findings highlight the potential of CzCNDSB for practical applications such as photodetectors and solar energy conversion.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
In this article,we comment on the article by Peta et al.This study evaluates the diagnostic performance of FibroTest-Actitest,transient elastography,and the fibrosis-4 index against a histological reference.Using the ...In this article,we comment on the article by Peta et al.This study evaluates the diagnostic performance of FibroTest-Actitest,transient elastography,and the fibrosis-4 index against a histological reference.Using the Obuchowski measure,the authors demonstrate that FibroTest and vibration-controlled transient elastography outperform the fibrosis-4 index in detecting fibrosis.Additionally,Actitest offers superior estimation of inflammatory activity compared to conventional biomarkers.Assessing liver fibrosis is crucial for managing autoimmune hepatitis(AIH),yet reliance on invasive liver biopsy remains higher than in other liver diseases.This is partly due to more complex diagnostic criteria for AIH,the lack of standardized scoring for non-invasive testing,and the presence of inflammation,which can lead to falsely elevated results with non-invasive tests.A Bayesian latent class model further supports the reliability of these non-invasive tests,highlighting their potential to complement biopsy,particularly for longterm disease monitoring.These findings underscore the importance of noninvasive diagnostics in optimizing AIH management.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
This study provides a thorough investigation into the vibration behavior and impulse response characteristics of composite honeycomb cylindrical shells filled with damping gel(DG-FHCSs).To address the limitations of e...This study provides a thorough investigation into the vibration behavior and impulse response characteristics of composite honeycomb cylindrical shells filled with damping gel(DG-FHCSs).To address the limitations of existing methods,a dynamic model is developed for both free and forced vibration scenarios.These models incorporate the virtual spring technology to accurately simulate a wide range of boundary conditions.Using the first-order shear deformation theory in conjunction with the Jacobi orthogonal polynomials,an energy expression is formulated,and the natural frequencies and mode shapes are determined via the Ritz method.Based on the Newmark-βmethod,the pulse response amplitudes and attenuation characteristics under various transient excitation loads are analyzed and evaluated.The accuracy of the theoretical model and the vibration suppression capability of the damping gel are experimentally validated.Furthermore,the effects of key structural parameters on the natural frequency and vibration response are systematically examined.展开更多
Herein,we report the design and synthesis of alternating donor-acceptor nanorings[3]C-NA and[4]C-NA,along with a reference linear molecule[3]L-NA,via electrochemical oxidation-induced reductive elimination of alkynyl ...Herein,we report the design and synthesis of alternating donor-acceptor nanorings[3]C-NA and[4]C-NA,along with a reference linear molecule[3]L-NA,via electrochemical oxidation-induced reductive elimination of alkynyl platinum(II)complexes.Unlike[3]L-NA,which exhibits charge defects at its end-groups,the cyclic structures of[3]C-NA and[4]C-NA facilitate enhanced electron delocalization,enabling efficient charge transfer in low-polarity toluene.In the polar solvent dichloromethane(DCM),the increased flexibility of[4]C-NA promotes intramolecular charge transfer and suppresses charge recombination.The observed faster intramolecular charge transfer and slower charge recombination rates in these nanoring acceptor materials suggest their potential for improving the power conversion efficiency of organic solar cells,providing valuable insights for the design of nanoring acceptor materials.展开更多
Objective Stroke is a main cause of disability and mortality worldwide.It has been reported that ischemic preconditioning(IP)has neuroprotective effects against stroke.This study aimed to verify the mechanism by which...Objective Stroke is a main cause of disability and mortality worldwide.It has been reported that ischemic preconditioning(IP)has neuroprotective effects against stroke.This study aimed to verify the mechanism by which calcium-sensing recep-tor(Casr)inhibition-mediated M2 microglial transformation in the IP protects against stroke,which will provide a potential therapeutic target for stroke.Methods Middle cerebral artery occlusion(MCAO)rats and oxygen-glucose deprivation(OGD)neurons were used in this study.IP was induced via the transient MCAO and OGD methods.RNA sequencing(RNA-Seq)was used to explore the underlying key molecules.Western blotting and immunohistochemistry were performed to detect the expression of Casr and the M1 and M2 microglial markers.CCK8 was used to detect cell viability.The calcium concentration was detected via the use of Fluo-4 AM,a fluorescence probe.The Casr inhibitor NPS2143 and the Casr activator R568 were used to explore the role of Casr in M2 microglial transformation and neuroprotection.Results We first revealed that IP induced M2 microglial transformation in ischemic injury.In addition,MCAO injury increased Casr expression and the calcium concentration,which was inhibited by IP.Furthermore,Casr activation inhibited the M2 microglial transformation induced by IP.Finally,we found that Casr inhibition improved the survival rate,alleviated neurological deficits,and reduced the infarct volume induced by MCAO.Conclusions We confirmed that Casr-related neuroprotection induced by IP is associated with the transformation of M2 microglia.These findings can be used to understand the protective mechanisms of IP against ischemic stroke.展开更多
文摘Through adding a nonlinear self-feedback term in the evolution equations of neural network, we introduced a transiently chaotic neural network model. In order to utilize the transiently chaotic dynamics mechanism in optimization problem efficiently, we have analyzed the dynamical procedure of the transiently chaotic neural network model and studied the function of the crucial bifurcation parameter which governs the chaotic behavior of the system. Based on the dynamical analysis of the transiently chaotic neural network model, chaotic annealing algorithm is also examined and improved. As an example, we applied chaotic annealing method to the traveling salesman problem and obtained good results.
基金Funding was provided by the Citrus Research and Development Foundation(CRDF),Inc.,Lake Alfred,FL,USA.
文摘Plants have a perception system triggered by pathogen and pest signals to initiate defense.These signals include evolutionarily conserved molecules from microbes and insects termed pathogen/herbivore-associated molecular patterns(PAMPs/HAMPs).Here we showed that hexaacetyl-chitohexaose(HC),an oligosaccharide from chitin,a structural component in insect exoskeletons and fungi cell walls,upregulated defense-associated genes WRKY22,GST1,RAR1,EDS1,PAL1 and NPR2,and downregulated ICS1 at 1 h after HC treatment in Sun Chu Sha mandarin leaves.The effect was transient as defense gene transcriptional changes were not observed at 18 h after the treatment.Electrical penetration graph(EPG)recordings were used to study the feeding behavior of Asian citrus psyllid(ACP)following the HC treatment.ACP is the hemipteran vector of Candidatus Liberibacter asiaticus(CLas),the pathogen associated with huanglongbing(HLB).Adult ACP displayed reduced intercellular probing,reduced xylem feeding count and duration,and increased non-probing activity on HC-treated citrus compared to controls.During an 18-h recording,percentage for total duration of xylem ingestion,phloem ingestion,intercellular probing were lower,and the percentage of nonprobing behavior was higher in HC-treated leaves than in controls.In host-selection behavior studies,HC treatment did not alter the attractiveness of citrus leaves under light or dark conditions.In addition,ACP feeding on HC-treated leaves did not show differences in mortality for up to 10 day of exposure.In summary,we report that HC induced a transient defense in citrus and an inhibitory effect on ACP feeding but did not affect host selection or the insect fitness under the tested conditions.
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.
文摘This study discusses the benefits and challenges of well monitoring for Gulong shale oil production.It examines the Unified Transient Analysis(UTA)method,which integrates rate and pressure data to monitor changes in fracture surface area and production efficiency in real-time.The UTA method allows for early detection of production impairments and provides feedback to optimize drawdown pressure,enhancing production without damaging fracture conductivity.Analysis of production data from Well A in the Daqing Oilfield demonstrates the method's efficacy,particularly in managing choke size adjustments and identifying fracture conductivity degradation.Despite its benefits,challenges such as data quality,manual data analysis,and the need for automated choke management are highlighted.The study underscores the necessity of integrating intelligent monitoring technologies and automating workflows to optimize Gulong shale oil production.
基金Supported by the National Natural Science Foundation of China(No.11071238)the Key Lab of Random Complex Structures and Data Science,CAS(No.2008DP173182)the National Center for Mathematics and Interdisciplinary Sciences,CAS(No.Y029184K51)
文摘Under the condition that the damping factor is between zero and one, chaotic dynamics is proved to exist in one-dimensional transiently chaotic neural networks by Li-Misiurewicz theorem. This result extends the previous result which is done under the condition that the damping factor is zero. Because the value of damping factor affects the speed of dynamical process of transiently chaotic neural networks, this result provides more complete theoretical basis for applications. Finally, two examples by numerical simulation are given to reinforce and illustrate this result.
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.
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 the National Science and Technology Major Project of China(Nos.2017-II-0004-0016 and J2019-I-0011-0011).
文摘Unstable operating conditions such as surge could cause damage to both aerodynamic performance and structural integrity of a compression system.This paper addresses the critical issue of aerodynamic instability in compressor design,particularly focusing on an axial-centrifugal combined compressor,a widely used yet underexplored configuration.An experimental investigation was conducted on a three-stage axial and one-stage centrifugal compressor(3A1C),using two pipe systems and employing fast-responding transducers to capture the dynamic instability process from choke condition to deep surge.Results reveal that at the design speed,3A1C enters deep surge directly,whereas at off-design speeds,it experiences rotating stall and mild surge across a wide mass flow range.Some special instability features in the combined compressor can be found in the steady state map and dynamic process.The characteristic curve of the first axial stage keeps a positive slope during the whole mass flow range at an off-design speed.The first stage could work stably on the stall characteristic curve because the centrifugal stage has stronger pressurization and plays a dominant role in global aerodynamic instability.Besides,rotating instability occurs at the first rotor tip and disappears as the back pressure increases,which is also rarely seen in a single-axial compressor.This is also related to the strong pressurization of the centrifugal stage.The findings of this paper will contribute to the understanding of aerodynamic instabilities in combined compressors.
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.
基金supported by the National Key Research and Development Program of China(Grant Nos.2018YFA0305900 and 2017YFA0403704)the National Natural Science Foundation of China(Grant Nos.61575079,51632002,11804113,and 51720105007)the Natural Science Foundation of Jilin Province,China(Grant No.20180101230JC).
文摘High pressure can alter the properties of matter and modulate the excited-state relaxation behavior of materials without chemical intervention.In this study,high pressure was combined with steady-state absorption and fluorescence spectroscopy,as well as transient spectroscopy techniques,to investigate its effect on the optical properties of the stimuliresponsive material(2Z,20Z)-2,20-(1,4-phenylene)bis(3-(4-(9H-carbazol-9-yl)phenyl)acrylonitrile)(CzCNDSB).With increasing pressure,the steady-state absorption and fluorescence peaks of CzCNDSB crystals exhibit red shifts,which are fully reversible.At the same time,pressure causes the molecules to pack more closely,leading to an increase in both the number and energy of multiplet self-trapped state,while the energy of local excited state decreases.The steady-state and transient results provide information on electronic energy levels,excited-state dynamics,and other properties of CzCNDSB,which show strong pressure dependence.These findings highlight the potential of CzCNDSB for practical applications such as photodetectors and solar energy conversion.
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.
文摘In this article,we comment on the article by Peta et al.This study evaluates the diagnostic performance of FibroTest-Actitest,transient elastography,and the fibrosis-4 index against a histological reference.Using the Obuchowski measure,the authors demonstrate that FibroTest and vibration-controlled transient elastography outperform the fibrosis-4 index in detecting fibrosis.Additionally,Actitest offers superior estimation of inflammatory activity compared to conventional biomarkers.Assessing liver fibrosis is crucial for managing autoimmune hepatitis(AIH),yet reliance on invasive liver biopsy remains higher than in other liver diseases.This is partly due to more complex diagnostic criteria for AIH,the lack of standardized scoring for non-invasive testing,and the presence of inflammation,which can lead to falsely elevated results with non-invasive tests.A Bayesian latent class model further supports the reliability of these non-invasive tests,highlighting their potential to complement biopsy,particularly for longterm disease monitoring.These findings underscore the importance of noninvasive diagnostics in optimizing AIH management.
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(Nos.12472005 and 52175079)the Aerospace Science Foundation of China(No.2022Z009050002)+2 种基金the Key Laboratory of Vibration and Control of Aero-Propulsion SystemMinistry of Education of China(No.VCAME201603)the Tai-Hang Laboratory Program(No.AK023)。
文摘This study provides a thorough investigation into the vibration behavior and impulse response characteristics of composite honeycomb cylindrical shells filled with damping gel(DG-FHCSs).To address the limitations of existing methods,a dynamic model is developed for both free and forced vibration scenarios.These models incorporate the virtual spring technology to accurately simulate a wide range of boundary conditions.Using the first-order shear deformation theory in conjunction with the Jacobi orthogonal polynomials,an energy expression is formulated,and the natural frequencies and mode shapes are determined via the Ritz method.Based on the Newmark-βmethod,the pulse response amplitudes and attenuation characteristics under various transient excitation loads are analyzed and evaluated.The accuracy of the theoretical model and the vibration suppression capability of the damping gel are experimentally validated.Furthermore,the effects of key structural parameters on the natural frequency and vibration response are systematically examined.
基金support from Natural Science Foundation of China(Nos.22271239,22171237,22071208,and 92356308)the Natural Science Foundation of Fujian Province(2022J01524)。
文摘Herein,we report the design and synthesis of alternating donor-acceptor nanorings[3]C-NA and[4]C-NA,along with a reference linear molecule[3]L-NA,via electrochemical oxidation-induced reductive elimination of alkynyl platinum(II)complexes.Unlike[3]L-NA,which exhibits charge defects at its end-groups,the cyclic structures of[3]C-NA and[4]C-NA facilitate enhanced electron delocalization,enabling efficient charge transfer in low-polarity toluene.In the polar solvent dichloromethane(DCM),the increased flexibility of[4]C-NA promotes intramolecular charge transfer and suppresses charge recombination.The observed faster intramolecular charge transfer and slower charge recombination rates in these nanoring acceptor materials suggest their potential for improving the power conversion efficiency of organic solar cells,providing valuable insights for the design of nanoring acceptor materials.
基金supported by the National Natural Science Foundation of China(grant numbers 81371440,82271454 and 81971195).
文摘Objective Stroke is a main cause of disability and mortality worldwide.It has been reported that ischemic preconditioning(IP)has neuroprotective effects against stroke.This study aimed to verify the mechanism by which calcium-sensing recep-tor(Casr)inhibition-mediated M2 microglial transformation in the IP protects against stroke,which will provide a potential therapeutic target for stroke.Methods Middle cerebral artery occlusion(MCAO)rats and oxygen-glucose deprivation(OGD)neurons were used in this study.IP was induced via the transient MCAO and OGD methods.RNA sequencing(RNA-Seq)was used to explore the underlying key molecules.Western blotting and immunohistochemistry were performed to detect the expression of Casr and the M1 and M2 microglial markers.CCK8 was used to detect cell viability.The calcium concentration was detected via the use of Fluo-4 AM,a fluorescence probe.The Casr inhibitor NPS2143 and the Casr activator R568 were used to explore the role of Casr in M2 microglial transformation and neuroprotection.Results We first revealed that IP induced M2 microglial transformation in ischemic injury.In addition,MCAO injury increased Casr expression and the calcium concentration,which was inhibited by IP.Furthermore,Casr activation inhibited the M2 microglial transformation induced by IP.Finally,we found that Casr inhibition improved the survival rate,alleviated neurological deficits,and reduced the infarct volume induced by MCAO.Conclusions We confirmed that Casr-related neuroprotection induced by IP is associated with the transformation of M2 microglia.These findings can be used to understand the protective mechanisms of IP against ischemic stroke.
