The synchronization and asynchronization of two coupled excitable systems are investigated. The two systems with different initial configurations, which are separately a single spiral wave (or a travel wave) and the r...The synchronization and asynchronization of two coupled excitable systems are investigated. The two systems with different initial configurations, which are separately a single spiral wave (or a travel wave) and the rest state, can be developed to the synchronizing state with the same spiral wave (or travel wave) in each system, when the coupling is very strong. Decreasing the coupling intensity, two rest states or two different configurations appear in the two systems. The qualitative analysis and interpretation are given.展开更多
We studied synchronization behaviours of spiral waves in a two-layer coupled inhomogeneous excitable system. It was found that phase synchronization can be observed under weak coupling strength. By increasing the coup...We studied synchronization behaviours of spiral waves in a two-layer coupled inhomogeneous excitable system. It was found that phase synchronization can be observed under weak coupling strength. By increasing the coupling strength, the synchronization is broken down. With the further increase of the coupling strength, complete synchronization and phase synchronization occur again. We also found that the inhomogeneity in excitable systems is helpful to the synchronization.展开更多
As China's high-speed railway technology advances,high-speed trains have emerged as a pivotal mode of transportation,instrumental in facilitating passenger and freight mobility while fostering robust regional eco-...As China's high-speed railway technology advances,high-speed trains have emerged as a pivotal mode of transportation,instrumental in facilitating passenger and freight mobility while fostering robust regional eco-nomic and trade interactions.Nonetheless,the safety of train operations remains a paramount concern,prompting extensive research into the dynamic behavior of critical components,which is essential to ensuring seamless and secure transportation services.This article commences by comprehensively reviewing the current landscape and evolutionary trajectory of dynamic model analysis for both traditional bearings and axle box bearings.Emphasis is placed on elucidating the profound influence of diverse bearing fault types on the system's kinematic state,alongside delving into the research methodologies employed in developing multi-physics field coupling models.Subsequently,it expounds on the content of investigations focusing on various wheel and track impairments,grounded in the dynamic modeling of the bearing vehicle coupling system.Concurrently,the intricate interplay between wheel-rail excitation and axle box bearing faults on the system's performance is elucidated.Concludingly,the article underscores the inadequacy of current multi-source fault diagnosis meth-odologies in tackling the intricacies of complex train operating environments,thereby highlighting its sig-nificance as a pressing and vital research agenda for the future.展开更多
The control effect of recycled noise,generated by the superposition of a primary Gaussian noise source and a secondary source with a constant delay,has been studied in an excitable FitzHugh-Nagumo system.We mainly foc...The control effect of recycled noise,generated by the superposition of a primary Gaussian noise source and a secondary source with a constant delay,has been studied in an excitable FitzHugh-Nagumo system.We mainly focus on the performance of noise-induced spike and coherence resonance in a parameter region sub-threshold to supercritical Hopf bifurcation.For fixed noise intensity,simulations show that the coherence(quantitatively measured by R,which is defined as the mean value of the spike interval time T normalized to its mean square root) and the emission velocity of the noise-induced spikes exhibit damped oscillations with the variation of delay time,demonstrating a new kind of multi-resonance phenomenon.Furthermore,the optimal delay times for resonance and the fast emission velocity are related to the inherent frequency of the system.It seems that there are some synchronization effects between the dynamic character of the system and the delay time of recycled noise.Our results give clear information about how one can control the coherence and emission velocity of the noise-induced spike in a rather effective way,by deliberately adjusting the delay time and the fraction of the secondary noise.展开更多
Undoubtedly, the sensory organs of biological systems have been evolved to accurately detect and locate the external stimuli, even if they are very weak. However, the mechanism underlying this ability is still not ful...Undoubtedly, the sensory organs of biological systems have been evolved to accurately detect and locate the external stimuli, even if they are very weak. However, the mechanism underlying this ability is still not fully understood. Previously, it had been shown that stochastic resonance may be a good candidate to explain this ability, by which the response of a system to an external signal is amplified by the presence of noise. Recently, it is pointed out that the initial phase diversity in external signals can be also served as a simple and feasible mechanism for weak signal detection or amplification in excitable neurons. We here make a brief review on this progress. We will show that there are two kinds of effects of initial phase diversity: one is the phase disorder, i.e., the initial phases are different and static, and the other is the phase noise, i.e., the initial phases are time-varying like noise. Both cases show that initial phase diversity in subthreshold periodic signals can indeed play a constructive role in the emergence of sustained spiking activity. As initial phase diversity can mimic different arrival times from source signal to sensory organs, these findings may provide a cue for understanding the hunting behaviors of some biological systems.展开更多
The fluorescence imaging (FLI) in the second near-infrared window (NIR-II, 1000–1700nm) has attracted considerable attention in the past decade. In contrast to conventional NIR-I window excitation (808nm/980nm), FLI ...The fluorescence imaging (FLI) in the second near-infrared window (NIR-II, 1000–1700nm) has attracted considerable attention in the past decade. In contrast to conventional NIR-I window excitation (808nm/980nm), FLI with NIR-II window excitation (1064nm/other wavelength beyond 1000nm) can afford deeper tissue penetration depth with high clarity due to the merits of suppressed photon scattering and diminished autofluorescence. In this review, we have summarized NIR-II window excitable/emissive organic/polymeric fluorophores recently developed. The characteristics of these fluorophores such as chemical structures and photophysical properties have also been critically discussed. Furthermore, the latest development of noninvasive in vivo FLI with NIR-II excitation was highlighted. The ideal imaging results emphasized the importance of NIR-II excitation of these fluorophores in enabling deep tissue penetration and high-resolution imaging. Finally, a perspective on the challenges and prospects of NIR-II excitable/emissive organic/polymeric fluorophores was also discussed. We expected this review will be served as a source of inspiration for researchers, stimulating the creation of novel NIR-II excitable fluorophores and fostering the development of bioimaging applications.展开更多
Background:Acupuncture is widely used in modulating brain excitability and motor function,as a form of complementary and alternative medicine.However,there is no existing meta-analysis evaluating the effectiveness and...Background:Acupuncture is widely used in modulating brain excitability and motor function,as a form of complementary and alternative medicine.However,there is no existing meta-analysis evaluating the effectiveness and safety of acupuncture on corticospinal excitability(CSE),and the credibility of the evidence has yet to be quantified.Objective:This study was designed to assess the efficacy and safety of electroacupuncture(EA)and manual acupuncture(MA)in enhancing brain excitability,specifically focusing on CSE as measured by transcranial magnetic stimulation(TMS).Search strategy:This study followed a systematic approach,searching 9 databases up to August 2024 and examining grey literature,in compliance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.Inclusion criteria:Studies were included if they compared the clinical efficacy of EA or MA with sham acupuncture,no treatment or usual training.Data extraction and analysis:Three investigators independently conducted literature screening,data extraction,and risk of bias assessment.The primary outcome focused on motor-evoked potentials as measured by TMS,with treatment effects quantified using mean differences or standardized mean differences between pre-and post-treatment.Subgroup analyses were conducted using mixed-effects models,while random-effects or fixed-effects models were used to estimate average treatment differences across studies.Results:Based on 34 studies involving 1031 adults,acupuncture techniques significantly enhanced CSE.EA had a greater impact than MA,with effect sizes of 0.53 mV vs 0.43 mV(95%confidence interval[CI]:[0.30,0.76],P<0.00001 vs 95%CI:[0.28,0.59],P<0.00001).The 5 most frequently used acupoints were LI4(Hegu,32 times),ST36(Zusanli,10 times),LI11(Quchi,7 times),TE5(Waiguan,6 times),and GB34(Yanglingquan,5 times).Conclusion:This systematic review indicates that both EA and MA could effectively and safely enhance CSE,bringing the corticospinal pathway closer to the threshold for firing,which may ultimately improve motor function.LI4,ST36,LI11,TE5 and GB34 are the most commonly used acupoints.展开更多
The inherent complexities of excitable cardiac,nervous,and skeletal muscle tissues pose great challenges in constructing artificial counterparts that closely resemble their natural bioelectrical,structural,and mechani...The inherent complexities of excitable cardiac,nervous,and skeletal muscle tissues pose great challenges in constructing artificial counterparts that closely resemble their natural bioelectrical,structural,and mechanical properties.Recent advances have increasingly revealed the beneficial impact of bioelectrical microenvironments on cellular behaviors,tissue regeneration,and therapeutic efficacy for excitable tissues.This review aims to unveil the mechanisms by which electrical microenvironments enhance the regeneration and functionality of excitable cells and tissues,considering both endogenous electrical cues from electroactive biomaterials and exogenous electrical stimuli from external electronic systems.We explore the synergistic effects of these electrical microenvironments,combined with structural and mechanical guidance,on the regeneration of excitable tissues using tissue engineering scaffolds.Additionally,the emergence of micro/nanoscale bioelectronics has significantly broadened this field,facilitating intimate interactions between implantable bioelectronics and excitable tissues across cellular,tissue,and organ levels.These interactions enable precise data acquisition and localized modulation of cell and tissue functionalities through intricately designed electronic components according to physiological needs.The integration of tissue engineering and bioelectronics promises optimal outcomes,highlighting a growing trend in developing living tissue construct-bioelectronic hybrids for restoring and monitoring damaged excitable tissues.Furthermore,we envision critical challenges in engineering the next-generation hybrids,focusing on integrated fabrication strategies,the development of ionic conductive biomaterials,and their convergence with biosensors.展开更多
The structural dynamic response reconstruction technology can extract unmeasured information from limited measured data,significantly impacting vibration control,load identification,parameter identification,fault diag...The structural dynamic response reconstruction technology can extract unmeasured information from limited measured data,significantly impacting vibration control,load identification,parameter identification,fault diagnosis,and related fields.This paper proposes a dynamic response reconstruction method based on the Kalman filter,which simultaneously identifies external excitation and reconstructs dynamic responses at unmeasured positions.The weighted least squares method determines the load weighting matrix for excitation identification,while the minimum variance unbiased estimation determines the Kalman filter gain.The excitation prediction Kalman filter is constructed through time,excitation,and measurement updates.Subsequently,the response at the target point is reconstructed using the state vector,observation matrix,and excitation influence matrix obtained through the excitation prediction Kalman filter algorithm.An algorithm for reconstructing responses in continuous system using the excitation prediction Kalman filtering algorithm in modal space is derived.The proposed structural dynamic response reconstruction method evaluates the response reconstruction and the load identification performance under various load types and errors through simulation examples.Results demonstrate the accurate excitation identification under different load conditions and simultaneous reconstruction of target point responses,verifying the feasibility and reliability of the proposed method.展开更多
The low-energy excited states in the neutron-deficient nucleus^(91)Ru were populated via the^(58)Ni(^(36)Ar,2p1nγ)^(91)Ru reaction at a beam energy of 111 MeV.Charged particles,neutrons,andγrays were emitted in the ...The low-energy excited states in the neutron-deficient nucleus^(91)Ru were populated via the^(58)Ni(^(36)Ar,2p1nγ)^(91)Ru reaction at a beam energy of 111 MeV.Charged particles,neutrons,andγrays were emitted in the reactions and detected using a DIAMANT CsI ball,neutron wall,and EXOGAM Ge clover array,respectively.Angular-correlation and linear polarization measurements were performed to determine the spins and parities of the excited states unambiguously.In addition to the previously reported states,a new low-energy-level structure of^(91)Ru,including one 7/2^(+)and two 11/2^(+)states,was established.Similar structures have also been reported in lighter N=47 even-odd isotones down to85Sr,which were expected to come from the three-neutron-holevg_(9/2)^(-3)configuration.A semiempirical shell model was used to explain the level systematics of the N=47 even-odd isotones.Calculated results indicated that the 7/2^(+)and the vg_(9/2)^(-3)states~are mainly associated with the seniority-threeν(g_(9/2))-3excitations,while the vg_(9/2)^(-3)level is most likely interpreted as a seniorityυ=1 configuration of three neutron holes in theνg_(9∕2)orbital_weakly coupled to a 2^(+)excitation of the^(88)Sr core.A comparison between the calculation and experiment shows that the two 11/2^(+)excited states display an increase in mixing with proton number Z added from^(87)Zr up to^(91)Ru.展开更多
We propose an effective surface plasmon resonance system designed to achieve both negative and positive Goos–H??nchen shifts in reflected light.This system comprises a metal film and an underlying medium,where the re...We propose an effective surface plasmon resonance system designed to achieve both negative and positive Goos–H??nchen shifts in reflected light.This system comprises a metal film and an underlying medium,where the real part of the permittivity of the underlying medium must be less than unity.Surface plasmon polaritons can be excited at the lower surface of the metal when light is incident from the air onto the upper surface of the metal.The excitation of surface plasmon polaritons leads to the exploration of the Goos–H??nchen shift(G–HS).Control over the negative and positive(G–HS)is investigated via the wavelength of the incident light.The magnitude of the G–HS is strongly dependent on the incident wavelength.A remarkable enhancement of both negative and positive G–HS in the reflected light is achieved at certain wavelengths and incident angles.Our system paves the way for exploring different characteristics of optical switching and micro-sensors with very high precision.展开更多
Subgrade settlement is a common issue in soil ground within earthquake-prone regions,posing a threat to the safe operation of train-slab track coupled system(TSCS)in high-speed railways(HSRs).This study aims to analyz...Subgrade settlement is a common issue in soil ground within earthquake-prone regions,posing a threat to the safe operation of train-slab track coupled system(TSCS)in high-speed railways(HSRs).This study aims to analyze the mechanical behavior evolution of TSCS under subgrade settlement and earthquake excitation.The refined numerical model of slab track under subgrade differential settlement is established.The short settlement wavelength of 10 m causes the separation between the base and subgrade.The dynamic model of TSCS under subgrade settlement and earthquake excitation is developed.The dynamic response of TSCS exhibits more pronounced fluctuations under the combined effects of subgrade settlement and earthquake excitation than under the effects of settlement or earthquake alone.The evaluation indexes for the running safety of train on slab track under different settlement wavelengths exhibit varying degrees of increase with settlement amplitude and are particularly sensitive to the short settlement wavelength of 10 m.The wheel unloading rate and derailment coefficient of TSCS increase with earthquake intensity.Under the settlement wavelength of 10 m and amplitude of 20 mm,the wheel unloading rate of TSCS exceeds the allowable limit when the earthquake intensity exceeds 0.17g,and the derailment coefficient exceeds the allowable limit when the earthquake intensity surpasses 0.29g.展开更多
With the rapid integration of renewable energy sources,modern power systems are increasingly challenged by heightened volatility and uncertainty.Doubly-fed variable-speed pumped storage units(DFVS-PSUs)have emerged as...With the rapid integration of renewable energy sources,modern power systems are increasingly challenged by heightened volatility and uncertainty.Doubly-fed variable-speed pumped storage units(DFVS-PSUs)have emerged as promising technologies for mitigating grid oscillations and enhancing system flexibility.However,the excitation converters in DFVS-PSUs are prone to significant issues such as elevated common-mode voltage(CMV)and neutral-point voltage(NPV)fluctuations,which can lead to electromagnetic interference and degrade transient performance.To address these challenges,an optimized virtual space vector pulse width modulation(OVSVPWM)strategy is proposed,aiming to suppress CMV and NPV simultaneously through coordinated multi-objective control.Specifically,a dynamic feedback mechanism is introduced to adjust the balancing factor of basic vectors in the synthesized virtual small vector in real-time,achieving autonomous balancing of the NPV.To address the excessive switching actions introduced by the OVSVPWM strategy,a phase duty ratio-based sequence reconstruction method is adopted,which reduces the total number of switching actions to half of the original.A zero-level buffering scheme is employed to reconstruct the single-phase voltage-level output sequence,achieving peak CMV suppression down to udc/6.Simulation results demonstrate that the proposed strategy significantly improves electromagnetic compatibility and operational stability while maintaining high power quality.展开更多
This paper deeply discusses the causes of gear howling noise,the identification and analysis of multi-source excitation,the transmission path of dynamic noise,simulation and experimental research,case analysis,optimiz...This paper deeply discusses the causes of gear howling noise,the identification and analysis of multi-source excitation,the transmission path of dynamic noise,simulation and experimental research,case analysis,optimization effect,etc.,aiming to better provide a certain guideline and reference for relevant researchers.展开更多
In deep drilling applications,such as those for geothermal energy,there are many challenges,such as those related to efficient operation of the drilling fluid(mud)pumping system.Legacy drilling rigs often use paired,p...In deep drilling applications,such as those for geothermal energy,there are many challenges,such as those related to efficient operation of the drilling fluid(mud)pumping system.Legacy drilling rigs often use paired,parallel-connected independent-excitation direct-current(DC)motors for mud pumps,that are supplied by a single power converter.This configuration results in electrical power imbalance,thus reducing its efficiency.This paper investigates this power imbalance issue in such legacy DC mud pump drive systems and offers an innovative solution in the form of a closed-loop control system for electrical load balancing.The paper first analyzes the drilling fluid circulation and electrical drive layout to develop an analytical model that can be used for electrical load balancing and related energy efficiency improvements.Based on this analysis,a feedback control system(so-called“current mirror”control system)is designed to balance the electrical load(i.e.,armature currents)of parallel-connected DC machines by adjusting the excitation current of one of the DC machines,thus mitigating the power imbalance of the electrical drive.Theproposed control systemeffectiveness has been validated,first through simulations,followed by experimental testing on a deep drilling rig during commissioning and field tests.The results demonstrate the practical viability of the proposed“current mirror”control system that can effectively and rather quickly equalize the armature currents of both DC machines in a parallel-connected electrical drive,and thus balance both the electrical and mechanical load of individual DC machines under realistic operating conditions of the mud pump electrical drive.展开更多
Objectives:Chronic stress can trigger neuroinflammation and gut microbiota alterations,contributing to post-stress disorders.Individual differences in stress responses,shaped by genetic and physiological factors,requi...Objectives:Chronic stress can trigger neuroinflammation and gut microbiota alterations,contributing to post-stress disorders.Individual differences in stress responses,shaped by genetic and physiological factors,require better characterization.We aimed to investigate the long-term effects of chronic stress in rats selectively bred for high and low nervous system excitability.Methods:Adult male rats from two strains selectively bred for high(HT)and low(LT)excitability thresholds of the nervous system underwent a 15-day chronic emotional-pain stress protocol.Behavioral assessments(elevated plusmaze),cytokine levels(TNF,IL-1β,IL-6,IL-10)in the hippocampus and amygdala measured by ELISA,glial fibrillary acidic protein(GFAP+)cell counts obtained via immunohistochemistry in the prefrontal cortex,hippocampus,and amygdala,and gutmicrobiota profiling(16S rRNAsequencing)were conducted on days 7 and 24 post-stress.Results:By day 24,LT rats exhibited reduced exploratory behavior,elevated proinflammatory cytokines,and decreased GFAP+cells across multiple brain regions.In contrast,HT rats exhibited an anxiety-like phenotype even in controls but showed increased exploratory activity after stress,without signs of brain inflammation;GFAP+reduction was limited to the hippocampus.Microbiota composition remained stable in LT rats but changed transiently in HT rats.Conclusion:Two distinct stress response patterns emerged:delayed neuroinflammatory and behavioral dysregulation with rigid microbiota in LT rats,vs.primarily behavioral changes with transient microbiota shifts in HT rats.These findings highlight the need to consider genetic excitability traits when modeling stress-related disorders and exploring potential therapeutic strategies.展开更多
Epilepsy is a leading cause of disability and mortality worldwide. However, despite the availability of more than 20 antiseizure medications, more than one-third of patients continue to experience seizures. Given the ...Epilepsy is a leading cause of disability and mortality worldwide. However, despite the availability of more than 20 antiseizure medications, more than one-third of patients continue to experience seizures. Given the urgent need to explore new treatment strategies for epilepsy, recent research has highlighted the potential of targeting gliosis, metabolic disturbances, and neural circuit abnormalities as therapeutic strategies. Astrocytes, the largest group of nonneuronal cells in the central nervous system, play several crucial roles in maintaining ionic and energy metabolic homeostasis in neurons, regulating neurotransmitter levels, and modulating synaptic plasticity. This article briefly reviews the critical role of astrocytes in maintaining balance within the central nervous system. Building on previous research, we discuss how astrocyte dysfunction contributes to the onset and progression of epilepsy through four key aspects: the imbalance between excitatory and inhibitory neuronal signaling, dysregulation of metabolic homeostasis in the neuronal microenvironment, neuroinflammation, and the formation of abnormal neural circuits. We summarize relevant basic research conducted over the past 5 years that has focused on modulating astrocytes as a therapeutic approach for epilepsy. We categorize the therapeutic targets proposed by these studies into four areas: restoration of the excitation–inhibition balance, reestablishment of metabolic homeostasis, modulation of immune and inflammatory responses, and reconstruction of abnormal neural circuits. These targets correspond to the pathophysiological mechanisms by which astrocytes contribute to epilepsy. Additionally, we need to consider the potential challenges and limitations of translating these identified therapeutic targets into clinical treatments. These limitations arise from interspecies differences between humans and animal models, as well as the complex comorbidities associated with epilepsy in humans. We also highlight valuable future research directions worth exploring in the treatment of epilepsy and the regulation of astrocytes, such as gene therapy and imaging strategies. The findings presented in this review may help open new therapeutic avenues for patients with drugresistant epilepsy and for those suffering from other central nervous system disorders associated with astrocytic dysfunction.展开更多
The precise excitation of molecular vibrational states is critical for ad-vancing chemical dynamics,preci-sion spectroscopy,and trace gas sensing.This objective,however,is often hindered by the weak oscilla-tor streng...The precise excitation of molecular vibrational states is critical for ad-vancing chemical dynamics,preci-sion spectroscopy,and trace gas sensing.This objective,however,is often hindered by the weak oscilla-tor strengths of ro-vibrational tran-sitions,which render conventional continuous-wave(cw)lasers ineffec-tive due to their limited power.This fundamental challenge is overcome by cavity-enhanced excitation(CEE),a technique that locks a cw laser to a high-finesse optical cavity.This configuration amplifies the intra-cavity light intensity by several orders of magnitude while preserving a narrow spectral linewidth.The resulting synergy enables highly efficient,state-selective population transfer and high-resolution spectroscopy previously considered impractical.This review elucidates the core technique of laser-cavity locking and highlights its applications,notably in the quantitative detection of trace isotopes and the investigation of highly excited vibrational states with kilo-hertz-level accuracy.展开更多
Ultrasound neuromodulation shows promise for treating neurological disorders,but the underlying mechanisms remain unclear.Here,we developed an integrated surface acoustic wave(SAW)ultrasound chip enabling simultaneous...Ultrasound neuromodulation shows promise for treating neurological disorders,but the underlying mechanisms remain unclear.Here,we developed an integrated surface acoustic wave(SAW)ultrasound chip enabling simultaneous electrophysiological recording and Ca^(2+) imaging of cultured hippocampal neurons to investigate neuronal excitability and synaptic transmission during ultrasound stimulation.This study revealed,for the first time,three distinct neuronal response patterns induced by SAW ultrasound:an immediate response showing rapid activation,a delayed response exhibiting facilitation after several minutes,and a non-response maintaining baseline activity.Ultrasound stimulation increased action potential firing,enhanced excitatory postsynaptic currents,and elevated intracellular Ca^(2+) levels.These effects were dependent on extracellular Ca^(2+) influx and primarily dominated by L-type Ca^(2+) channels.Our findings suggest that individual neurons exhibit heterogeneous responses to SAW ultrasound stimulation based on their intracellular Ca^(2+) levels and L-type Ca^(2+) channel activity.This integrated approach provides new insights into the cellular mechanisms of ultrasound neuromodulation while highlighting the potential of SAW technology for precise,cell-type-specific neural control.展开更多
In order to realize the comprehensive utilization of industrial solid waste rice husk ash and heavy metal cadmium contaminated soil,rice husk ash-based geopolymer prepared by alkaline activator was used to modify cadm...In order to realize the comprehensive utilization of industrial solid waste rice husk ash and heavy metal cadmium contaminated soil,rice husk ash-based geopolymer prepared by alkaline activator was used to modify cadmium contaminated soil.The main physical and chemical properties of rice husk ash were clarified by SEM,XRF and X-ray diffraction.The unconfined compressive strength test and toxicity leaching test were carried out on the modified soil.Combined with FTIR and TG micro-level,the solidification mechanism of rice husk ash-based geopolymer solidified cadmium contaminated soil was discussed.The results show that the strength of geopolymer modified soil is significantly higher than that of plain soil,and the unconfined compressive strength at 7 d age is 4.2 times that of plain soil.The strength of modified soil with different dosage of geopolymer at 28 d age is about 36% to 40% higher than that of modified soil at 7 d age.Geopolymer has a significant effect on the leaching of heavy metals in contaminated soil.When the cadmium content is 100 mg/kg,it meets the standard limit.In the process of complex depolymerization-condensation reaction,on the one hand,geopolymers are cemented and agglomerated to form a complex spatial structure,which affects the macro and micro characteristics of soil.On the other hand,it has significant adsorption,precipitation and replacement effects on heavy metal ions in soil,showing good strength and low heavy metal leaching toxicity.展开更多
基金国家重点基础研究发展计划(973计划)，国家自然科学基金，the Innovation Funds for Laser Technology，国家自然科学基金，the Science Foundation of the China Academy of Engineering Physics
文摘The synchronization and asynchronization of two coupled excitable systems are investigated. The two systems with different initial configurations, which are separately a single spiral wave (or a travel wave) and the rest state, can be developed to the synchronizing state with the same spiral wave (or travel wave) in each system, when the coupling is very strong. Decreasing the coupling intensity, two rest states or two different configurations appear in the two systems. The qualitative analysis and interpretation are given.
基金Project supported by the National Natural Science Foundation of China (Grant No 10305005)the Fundamental Research Fund for Physics and Mathematics of Lanzhou University, China
文摘We studied synchronization behaviours of spiral waves in a two-layer coupled inhomogeneous excitable system. It was found that phase synchronization can be observed under weak coupling strength. By increasing the coupling strength, the synchronization is broken down. With the further increase of the coupling strength, complete synchronization and phase synchronization occur again. We also found that the inhomogeneity in excitable systems is helpful to the synchronization.
基金Supported by the National Natural Science Foundation of China(Grant Nos.12393783,12302067,12172235,52072249)Joint Funds of the National Natural Science Foundation of China(Grant No.U24A2003)+3 种基金College Education Scientific Research Project of Hebei Province(Grant No.JZX2024006)Central Guiding Local Scientific and Technological Development Funding Project(Grant No.246Z2206G)the Key Research Project of China State Railway Group Co.,Ltd.(Grant No.N2024T009)S&T Program of Hebei(Grant No.21567622H).
文摘As China's high-speed railway technology advances,high-speed trains have emerged as a pivotal mode of transportation,instrumental in facilitating passenger and freight mobility while fostering robust regional eco-nomic and trade interactions.Nonetheless,the safety of train operations remains a paramount concern,prompting extensive research into the dynamic behavior of critical components,which is essential to ensuring seamless and secure transportation services.This article commences by comprehensively reviewing the current landscape and evolutionary trajectory of dynamic model analysis for both traditional bearings and axle box bearings.Emphasis is placed on elucidating the profound influence of diverse bearing fault types on the system's kinematic state,alongside delving into the research methodologies employed in developing multi-physics field coupling models.Subsequently,it expounds on the content of investigations focusing on various wheel and track impairments,grounded in the dynamic modeling of the bearing vehicle coupling system.Concurrently,the intricate interplay between wheel-rail excitation and axle box bearing faults on the system's performance is elucidated.Concludingly,the article underscores the inadequacy of current multi-source fault diagnosis meth-odologies in tackling the intricacies of complex train operating environments,thereby highlighting its sig-nificance as a pressing and vital research agenda for the future.
基金supported by the National Natural Science Foundation of China (21073232)the Fundamental Research Funds for the Central Universities (2010QNA16)the Research Fund of China University of Mining and Technology
文摘The control effect of recycled noise,generated by the superposition of a primary Gaussian noise source and a secondary source with a constant delay,has been studied in an excitable FitzHugh-Nagumo system.We mainly focus on the performance of noise-induced spike and coherence resonance in a parameter region sub-threshold to supercritical Hopf bifurcation.For fixed noise intensity,simulations show that the coherence(quantitatively measured by R,which is defined as the mean value of the spike interval time T normalized to its mean square root) and the emission velocity of the noise-induced spikes exhibit damped oscillations with the variation of delay time,demonstrating a new kind of multi-resonance phenomenon.Furthermore,the optimal delay times for resonance and the fast emission velocity are related to the inherent frequency of the system.It seems that there are some synchronization effects between the dynamic character of the system and the delay time of recycled noise.Our results give clear information about how one can control the coherence and emission velocity of the noise-induced spike in a rather effective way,by deliberately adjusting the delay time and the fraction of the secondary noise.
基金supported by the National Natural Science Foundation of China(Grant No.11305078)
文摘Undoubtedly, the sensory organs of biological systems have been evolved to accurately detect and locate the external stimuli, even if they are very weak. However, the mechanism underlying this ability is still not fully understood. Previously, it had been shown that stochastic resonance may be a good candidate to explain this ability, by which the response of a system to an external signal is amplified by the presence of noise. Recently, it is pointed out that the initial phase diversity in external signals can be also served as a simple and feasible mechanism for weak signal detection or amplification in excitable neurons. We here make a brief review on this progress. We will show that there are two kinds of effects of initial phase diversity: one is the phase disorder, i.e., the initial phases are different and static, and the other is the phase noise, i.e., the initial phases are time-varying like noise. Both cases show that initial phase diversity in subthreshold periodic signals can indeed play a constructive role in the emergence of sustained spiking activity. As initial phase diversity can mimic different arrival times from source signal to sensory organs, these findings may provide a cue for understanding the hunting behaviors of some biological systems.
基金supported by the National Nature Science Foundation of China(Nos.62075079,62305127,61975200)the Natural Science Foundation of Jilin Province(20230508135RC)the Science and Technology Development Foundation of Changchun City(23GZZ15).
文摘The fluorescence imaging (FLI) in the second near-infrared window (NIR-II, 1000–1700nm) has attracted considerable attention in the past decade. In contrast to conventional NIR-I window excitation (808nm/980nm), FLI with NIR-II window excitation (1064nm/other wavelength beyond 1000nm) can afford deeper tissue penetration depth with high clarity due to the merits of suppressed photon scattering and diminished autofluorescence. In this review, we have summarized NIR-II window excitable/emissive organic/polymeric fluorophores recently developed. The characteristics of these fluorophores such as chemical structures and photophysical properties have also been critically discussed. Furthermore, the latest development of noninvasive in vivo FLI with NIR-II excitation was highlighted. The ideal imaging results emphasized the importance of NIR-II excitation of these fluorophores in enabling deep tissue penetration and high-resolution imaging. Finally, a perspective on the challenges and prospects of NIR-II excitable/emissive organic/polymeric fluorophores was also discussed. We expected this review will be served as a source of inspiration for researchers, stimulating the creation of novel NIR-II excitable fluorophores and fostering the development of bioimaging applications.
文摘Background:Acupuncture is widely used in modulating brain excitability and motor function,as a form of complementary and alternative medicine.However,there is no existing meta-analysis evaluating the effectiveness and safety of acupuncture on corticospinal excitability(CSE),and the credibility of the evidence has yet to be quantified.Objective:This study was designed to assess the efficacy and safety of electroacupuncture(EA)and manual acupuncture(MA)in enhancing brain excitability,specifically focusing on CSE as measured by transcranial magnetic stimulation(TMS).Search strategy:This study followed a systematic approach,searching 9 databases up to August 2024 and examining grey literature,in compliance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.Inclusion criteria:Studies were included if they compared the clinical efficacy of EA or MA with sham acupuncture,no treatment or usual training.Data extraction and analysis:Three investigators independently conducted literature screening,data extraction,and risk of bias assessment.The primary outcome focused on motor-evoked potentials as measured by TMS,with treatment effects quantified using mean differences or standardized mean differences between pre-and post-treatment.Subgroup analyses were conducted using mixed-effects models,while random-effects or fixed-effects models were used to estimate average treatment differences across studies.Results:Based on 34 studies involving 1031 adults,acupuncture techniques significantly enhanced CSE.EA had a greater impact than MA,with effect sizes of 0.53 mV vs 0.43 mV(95%confidence interval[CI]:[0.30,0.76],P<0.00001 vs 95%CI:[0.28,0.59],P<0.00001).The 5 most frequently used acupoints were LI4(Hegu,32 times),ST36(Zusanli,10 times),LI11(Quchi,7 times),TE5(Waiguan,6 times),and GB34(Yanglingquan,5 times).Conclusion:This systematic review indicates that both EA and MA could effectively and safely enhance CSE,bringing the corticospinal pathway closer to the threshold for firing,which may ultimately improve motor function.LI4,ST36,LI11,TE5 and GB34 are the most commonly used acupoints.
基金financially supported by the National Natural Science Foundation of China(Nos.52125501,52405325)the Key Research Project of Shaanxi Province(Nos.2021LLRH-08,2024SF2-GJHX-34)+5 种基金the Program for Innovation Team of Shaanxi Province(No.2023-CX-TD17)the Postdoctoral Fellowship Program of CPSF(No.GZB20230573)the Postdoctoral Project of Shaanxi Province(No.2023BSHYDZZ30)the Basic Research Program of Natural Science in Shaanxi Province(No.2021JQ-906)the China Postdoctoral Science Foundationthe Fundamental Research Funds for the Central Universities。
文摘The inherent complexities of excitable cardiac,nervous,and skeletal muscle tissues pose great challenges in constructing artificial counterparts that closely resemble their natural bioelectrical,structural,and mechanical properties.Recent advances have increasingly revealed the beneficial impact of bioelectrical microenvironments on cellular behaviors,tissue regeneration,and therapeutic efficacy for excitable tissues.This review aims to unveil the mechanisms by which electrical microenvironments enhance the regeneration and functionality of excitable cells and tissues,considering both endogenous electrical cues from electroactive biomaterials and exogenous electrical stimuli from external electronic systems.We explore the synergistic effects of these electrical microenvironments,combined with structural and mechanical guidance,on the regeneration of excitable tissues using tissue engineering scaffolds.Additionally,the emergence of micro/nanoscale bioelectronics has significantly broadened this field,facilitating intimate interactions between implantable bioelectronics and excitable tissues across cellular,tissue,and organ levels.These interactions enable precise data acquisition and localized modulation of cell and tissue functionalities through intricately designed electronic components according to physiological needs.The integration of tissue engineering and bioelectronics promises optimal outcomes,highlighting a growing trend in developing living tissue construct-bioelectronic hybrids for restoring and monitoring damaged excitable tissues.Furthermore,we envision critical challenges in engineering the next-generation hybrids,focusing on integrated fabrication strategies,the development of ionic conductive biomaterials,and their convergence with biosensors.
基金supported by the National Natural Science Foundation of China(Nos.12372066,U23B6009,52171261)the Aeronautical Science Fund(No.20240013052002)the Qing Lan Project。
文摘The structural dynamic response reconstruction technology can extract unmeasured information from limited measured data,significantly impacting vibration control,load identification,parameter identification,fault diagnosis,and related fields.This paper proposes a dynamic response reconstruction method based on the Kalman filter,which simultaneously identifies external excitation and reconstructs dynamic responses at unmeasured positions.The weighted least squares method determines the load weighting matrix for excitation identification,while the minimum variance unbiased estimation determines the Kalman filter gain.The excitation prediction Kalman filter is constructed through time,excitation,and measurement updates.Subsequently,the response at the target point is reconstructed using the state vector,observation matrix,and excitation influence matrix obtained through the excitation prediction Kalman filter algorithm.An algorithm for reconstructing responses in continuous system using the excitation prediction Kalman filtering algorithm in modal space is derived.The proposed structural dynamic response reconstruction method evaluates the response reconstruction and the load identification performance under various load types and errors through simulation examples.Results demonstrate the accurate excitation identification under different load conditions and simultaneous reconstruction of target point responses,verifying the feasibility and reliability of the proposed method.
文摘The low-energy excited states in the neutron-deficient nucleus^(91)Ru were populated via the^(58)Ni(^(36)Ar,2p1nγ)^(91)Ru reaction at a beam energy of 111 MeV.Charged particles,neutrons,andγrays were emitted in the reactions and detected using a DIAMANT CsI ball,neutron wall,and EXOGAM Ge clover array,respectively.Angular-correlation and linear polarization measurements were performed to determine the spins and parities of the excited states unambiguously.In addition to the previously reported states,a new low-energy-level structure of^(91)Ru,including one 7/2^(+)and two 11/2^(+)states,was established.Similar structures have also been reported in lighter N=47 even-odd isotones down to85Sr,which were expected to come from the three-neutron-holevg_(9/2)^(-3)configuration.A semiempirical shell model was used to explain the level systematics of the N=47 even-odd isotones.Calculated results indicated that the 7/2^(+)and the vg_(9/2)^(-3)states~are mainly associated with the seniority-threeν(g_(9/2))-3excitations,while the vg_(9/2)^(-3)level is most likely interpreted as a seniorityυ=1 configuration of three neutron holes in theνg_(9∕2)orbital_weakly coupled to a 2^(+)excitation of the^(88)Sr core.A comparison between the calculation and experiment shows that the two 11/2^(+)excited states display an increase in mixing with proton number Z added from^(87)Zr up to^(91)Ru.
基金Hubei University of Automotive Technology through the start-up research grant(BK202212),located in Shiyan 442002,China。
文摘We propose an effective surface plasmon resonance system designed to achieve both negative and positive Goos–H??nchen shifts in reflected light.This system comprises a metal film and an underlying medium,where the real part of the permittivity of the underlying medium must be less than unity.Surface plasmon polaritons can be excited at the lower surface of the metal when light is incident from the air onto the upper surface of the metal.The excitation of surface plasmon polaritons leads to the exploration of the Goos–H??nchen shift(G–HS).Control over the negative and positive(G–HS)is investigated via the wavelength of the incident light.The magnitude of the G–HS is strongly dependent on the incident wavelength.A remarkable enhancement of both negative and positive G–HS in the reflected light is achieved at certain wavelengths and incident angles.Our system paves the way for exploring different characteristics of optical switching and micro-sensors with very high precision.
基金Project(52078501)supported by the National Natural Science Foundation of ChinaProject(2022-Major-14)supported by the Science and Technology Research and Development Program Project of China Railway Group LimitedProject(2023ZZTS0342)supported by the Fundamental Research Funds for the Central Universities,China。
文摘Subgrade settlement is a common issue in soil ground within earthquake-prone regions,posing a threat to the safe operation of train-slab track coupled system(TSCS)in high-speed railways(HSRs).This study aims to analyze the mechanical behavior evolution of TSCS under subgrade settlement and earthquake excitation.The refined numerical model of slab track under subgrade differential settlement is established.The short settlement wavelength of 10 m causes the separation between the base and subgrade.The dynamic model of TSCS under subgrade settlement and earthquake excitation is developed.The dynamic response of TSCS exhibits more pronounced fluctuations under the combined effects of subgrade settlement and earthquake excitation than under the effects of settlement or earthquake alone.The evaluation indexes for the running safety of train on slab track under different settlement wavelengths exhibit varying degrees of increase with settlement amplitude and are particularly sensitive to the short settlement wavelength of 10 m.The wheel unloading rate and derailment coefficient of TSCS increase with earthquake intensity.Under the settlement wavelength of 10 m and amplitude of 20 mm,the wheel unloading rate of TSCS exceeds the allowable limit when the earthquake intensity exceeds 0.17g,and the derailment coefficient exceeds the allowable limit when the earthquake intensity surpasses 0.29g.
文摘With the rapid integration of renewable energy sources,modern power systems are increasingly challenged by heightened volatility and uncertainty.Doubly-fed variable-speed pumped storage units(DFVS-PSUs)have emerged as promising technologies for mitigating grid oscillations and enhancing system flexibility.However,the excitation converters in DFVS-PSUs are prone to significant issues such as elevated common-mode voltage(CMV)and neutral-point voltage(NPV)fluctuations,which can lead to electromagnetic interference and degrade transient performance.To address these challenges,an optimized virtual space vector pulse width modulation(OVSVPWM)strategy is proposed,aiming to suppress CMV and NPV simultaneously through coordinated multi-objective control.Specifically,a dynamic feedback mechanism is introduced to adjust the balancing factor of basic vectors in the synthesized virtual small vector in real-time,achieving autonomous balancing of the NPV.To address the excessive switching actions introduced by the OVSVPWM strategy,a phase duty ratio-based sequence reconstruction method is adopted,which reduces the total number of switching actions to half of the original.A zero-level buffering scheme is employed to reconstruct the single-phase voltage-level output sequence,achieving peak CMV suppression down to udc/6.Simulation results demonstrate that the proposed strategy significantly improves electromagnetic compatibility and operational stability while maintaining high power quality.
文摘This paper deeply discusses the causes of gear howling noise,the identification and analysis of multi-source excitation,the transmission path of dynamic noise,simulation and experimental research,case analysis,optimization effect,etc.,aiming to better provide a certain guideline and reference for relevant researchers.
文摘In deep drilling applications,such as those for geothermal energy,there are many challenges,such as those related to efficient operation of the drilling fluid(mud)pumping system.Legacy drilling rigs often use paired,parallel-connected independent-excitation direct-current(DC)motors for mud pumps,that are supplied by a single power converter.This configuration results in electrical power imbalance,thus reducing its efficiency.This paper investigates this power imbalance issue in such legacy DC mud pump drive systems and offers an innovative solution in the form of a closed-loop control system for electrical load balancing.The paper first analyzes the drilling fluid circulation and electrical drive layout to develop an analytical model that can be used for electrical load balancing and related energy efficiency improvements.Based on this analysis,a feedback control system(so-called“current mirror”control system)is designed to balance the electrical load(i.e.,armature currents)of parallel-connected DC machines by adjusting the excitation current of one of the DC machines,thus mitigating the power imbalance of the electrical drive.Theproposed control systemeffectiveness has been validated,first through simulations,followed by experimental testing on a deep drilling rig during commissioning and field tests.The results demonstrate the practical viability of the proposed“current mirror”control system that can effectively and rather quickly equalize the armature currents of both DC machines in a parallel-connected electrical drive,and thus balance both the electrical and mechanical load of individual DC machines under realistic operating conditions of the mud pump electrical drive.
基金supported by the Priority 2030 Federal Academic Leadership Programat Immanuel Kant Baltic Federal Universityongoing federal budget funding to Pavlov Institute of Physiology of the Russian Academy of Sciences(No.1021062411629-7-3.1.4).
文摘Objectives:Chronic stress can trigger neuroinflammation and gut microbiota alterations,contributing to post-stress disorders.Individual differences in stress responses,shaped by genetic and physiological factors,require better characterization.We aimed to investigate the long-term effects of chronic stress in rats selectively bred for high and low nervous system excitability.Methods:Adult male rats from two strains selectively bred for high(HT)and low(LT)excitability thresholds of the nervous system underwent a 15-day chronic emotional-pain stress protocol.Behavioral assessments(elevated plusmaze),cytokine levels(TNF,IL-1β,IL-6,IL-10)in the hippocampus and amygdala measured by ELISA,glial fibrillary acidic protein(GFAP+)cell counts obtained via immunohistochemistry in the prefrontal cortex,hippocampus,and amygdala,and gutmicrobiota profiling(16S rRNAsequencing)were conducted on days 7 and 24 post-stress.Results:By day 24,LT rats exhibited reduced exploratory behavior,elevated proinflammatory cytokines,and decreased GFAP+cells across multiple brain regions.In contrast,HT rats exhibited an anxiety-like phenotype even in controls but showed increased exploratory activity after stress,without signs of brain inflammation;GFAP+reduction was limited to the hippocampus.Microbiota composition remained stable in LT rats but changed transiently in HT rats.Conclusion:Two distinct stress response patterns emerged:delayed neuroinflammatory and behavioral dysregulation with rigid microbiota in LT rats,vs.primarily behavioral changes with transient microbiota shifts in HT rats.These findings highlight the need to consider genetic excitability traits when modeling stress-related disorders and exploring potential therapeutic strategies.
基金supported by the National Key Research and Development Program of China,No. 2023YFF0714200 (to CW)the National Natural Science Foundation of China,Nos. 82472038 and 82202224 (both to CW)+3 种基金the Shanghai Rising-Star Program,No. 23QA1407700 (to CW)the Construction Project of Shanghai Key Laboratory of Molecular Imaging,No. 18DZ2260400 (to CW)the National Science Foundation for Distinguished Young Scholars,No. 82025019 (to CL)the Greater Bay Area Institute of Precision Medicine (Guangzhou)(to CW)。
文摘Epilepsy is a leading cause of disability and mortality worldwide. However, despite the availability of more than 20 antiseizure medications, more than one-third of patients continue to experience seizures. Given the urgent need to explore new treatment strategies for epilepsy, recent research has highlighted the potential of targeting gliosis, metabolic disturbances, and neural circuit abnormalities as therapeutic strategies. Astrocytes, the largest group of nonneuronal cells in the central nervous system, play several crucial roles in maintaining ionic and energy metabolic homeostasis in neurons, regulating neurotransmitter levels, and modulating synaptic plasticity. This article briefly reviews the critical role of astrocytes in maintaining balance within the central nervous system. Building on previous research, we discuss how astrocyte dysfunction contributes to the onset and progression of epilepsy through four key aspects: the imbalance between excitatory and inhibitory neuronal signaling, dysregulation of metabolic homeostasis in the neuronal microenvironment, neuroinflammation, and the formation of abnormal neural circuits. We summarize relevant basic research conducted over the past 5 years that has focused on modulating astrocytes as a therapeutic approach for epilepsy. We categorize the therapeutic targets proposed by these studies into four areas: restoration of the excitation–inhibition balance, reestablishment of metabolic homeostasis, modulation of immune and inflammatory responses, and reconstruction of abnormal neural circuits. These targets correspond to the pathophysiological mechanisms by which astrocytes contribute to epilepsy. Additionally, we need to consider the potential challenges and limitations of translating these identified therapeutic targets into clinical treatments. These limitations arise from interspecies differences between humans and animal models, as well as the complex comorbidities associated with epilepsy in humans. We also highlight valuable future research directions worth exploring in the treatment of epilepsy and the regulation of astrocytes, such as gene therapy and imaging strategies. The findings presented in this review may help open new therapeutic avenues for patients with drugresistant epilepsy and for those suffering from other central nervous system disorders associated with astrocytic dysfunction.
基金supported by the Chinese Acade-my of Sciences(Grant Nos.YSBR-055,XDB0970100)the National Natural Science Foundation of China(Nos.22241302,12393825).
文摘The precise excitation of molecular vibrational states is critical for ad-vancing chemical dynamics,preci-sion spectroscopy,and trace gas sensing.This objective,however,is often hindered by the weak oscilla-tor strengths of ro-vibrational tran-sitions,which render conventional continuous-wave(cw)lasers ineffec-tive due to their limited power.This fundamental challenge is overcome by cavity-enhanced excitation(CEE),a technique that locks a cw laser to a high-finesse optical cavity.This configuration amplifies the intra-cavity light intensity by several orders of magnitude while preserving a narrow spectral linewidth.The resulting synergy enables highly efficient,state-selective population transfer and high-resolution spectroscopy previously considered impractical.This review elucidates the core technique of laser-cavity locking and highlights its applications,notably in the quantitative detection of trace isotopes and the investigation of highly excited vibrational states with kilo-hertz-level accuracy.
基金supported by the National Key Research&Development Program of China(2022YFC3602700,2022YFC3602702)the Science and Technology Innovation 2030-Brain Science and Brain-Inspired Intelligence Project(2021ZD0201301)+2 种基金the National Natural Science Foundation of China(12034015,62088101,32170688,323B1004)Program of Shanghai Academic Research Leader(21XD1403600)Shanghai Municipal Science and Technology Major Project(2021SHZDZX0100,2018SHZDZX01).
文摘Ultrasound neuromodulation shows promise for treating neurological disorders,but the underlying mechanisms remain unclear.Here,we developed an integrated surface acoustic wave(SAW)ultrasound chip enabling simultaneous electrophysiological recording and Ca^(2+) imaging of cultured hippocampal neurons to investigate neuronal excitability and synaptic transmission during ultrasound stimulation.This study revealed,for the first time,three distinct neuronal response patterns induced by SAW ultrasound:an immediate response showing rapid activation,a delayed response exhibiting facilitation after several minutes,and a non-response maintaining baseline activity.Ultrasound stimulation increased action potential firing,enhanced excitatory postsynaptic currents,and elevated intracellular Ca^(2+) levels.These effects were dependent on extracellular Ca^(2+) influx and primarily dominated by L-type Ca^(2+) channels.Our findings suggest that individual neurons exhibit heterogeneous responses to SAW ultrasound stimulation based on their intracellular Ca^(2+) levels and L-type Ca^(2+) channel activity.This integrated approach provides new insights into the cellular mechanisms of ultrasound neuromodulation while highlighting the potential of SAW technology for precise,cell-type-specific neural control.
基金Funded by Central Guiding Local Science and Technology Development Special Fund Project(No.ZYYD2023B02)Innovation and Entrepreneurship Training Program for College Students in Xinjiang Uygur Autonomous Region(No.S202410994015)+2 种基金China University of Mining and Technology Coal Fine Exploration and Intelligent Development National Key Laboratory Xinjiang Engineering College Joint Fund(No.SKLCRSM-XJIE24KF001)Basic Research Funds for Autonomous Region Universities(No.XJEDU2024P082)National Natural Science Foundation of China(No.41662017)。
文摘In order to realize the comprehensive utilization of industrial solid waste rice husk ash and heavy metal cadmium contaminated soil,rice husk ash-based geopolymer prepared by alkaline activator was used to modify cadmium contaminated soil.The main physical and chemical properties of rice husk ash were clarified by SEM,XRF and X-ray diffraction.The unconfined compressive strength test and toxicity leaching test were carried out on the modified soil.Combined with FTIR and TG micro-level,the solidification mechanism of rice husk ash-based geopolymer solidified cadmium contaminated soil was discussed.The results show that the strength of geopolymer modified soil is significantly higher than that of plain soil,and the unconfined compressive strength at 7 d age is 4.2 times that of plain soil.The strength of modified soil with different dosage of geopolymer at 28 d age is about 36% to 40% higher than that of modified soil at 7 d age.Geopolymer has a significant effect on the leaching of heavy metals in contaminated soil.When the cadmium content is 100 mg/kg,it meets the standard limit.In the process of complex depolymerization-condensation reaction,on the one hand,geopolymers are cemented and agglomerated to form a complex spatial structure,which affects the macro and micro characteristics of soil.On the other hand,it has significant adsorption,precipitation and replacement effects on heavy metal ions in soil,showing good strength and low heavy metal leaching toxicity.
