[Background]High harmonic cavities are widely used in electron storage rings to lengthen thebunch,lower the bunch peak current,thereby reducing the IBS effect,enhancing the Touschek lifetime,as well asproviding Landau...[Background]High harmonic cavities are widely used in electron storage rings to lengthen thebunch,lower the bunch peak current,thereby reducing the IBS effect,enhancing the Touschek lifetime,as well asproviding Landau damping,which is particularly important for storage rings operating with ultra-low emittance or atlow beam energy.[Purpose]To further increase the bunch length without additional hardware costs,the phasemodulation in a dual-RF system is considered.[Methods]In this paper,turn-by-turn simulations incorporating randomsynchrotron radiation excitation are conducted,and a brief analysis is presented to explain the bunch lengtheningmechanism.[Results]Simulation results reveal that the peak current can be further reduced,thereby mitigating IBSeffects and enhancing the Touschek lifetime.Although the energy spread increases,which tends to reduce thebrightness of higher-harmonic radiation from the undulator,the brightness of the fundamental harmonic can,in fact,beimproved.展开更多
While reinforcement learning-based underwater acoustic adaptive modulation shows promise for enabling environment-adaptive communication as supported by extensive simulation-based research,its practical performance re...While reinforcement learning-based underwater acoustic adaptive modulation shows promise for enabling environment-adaptive communication as supported by extensive simulation-based research,its practical performance remains underexplored in field investigations.To evaluate the practical applicability of this emerging technique in adverse shallow sea channels,a field experiment was conducted using three communication modes:orthogonal frequency division multiplexing(OFDM),M-ary frequency-shift keying(MFSK),and direct sequence spread spectrum(DSSS)for reinforcement learning-driven adaptive modulation.Specifically,a Q-learning method is used to select the optimal modulation mode according to the channel quality quantified by signal-to-noise ratio,multipath spread length,and Doppler frequency offset.Experimental results demonstrate that the reinforcement learning-based adaptive modulation scheme outperformed fixed threshold detection in terms of total throughput and average bit error rate,surpassing conventional adaptive modulation strategies.展开更多
Modulations of mitochondrial dysfunction,which involve a series of dynamic processes such as mitochondrial biogenesis,mitochondrial fusion and fission,mitochondrial transport,mitochondrial autophagy,mitochondrial apop...Modulations of mitochondrial dysfunction,which involve a series of dynamic processes such as mitochondrial biogenesis,mitochondrial fusion and fission,mitochondrial transport,mitochondrial autophagy,mitochondrial apoptosis,and oxidative stress,play an important role in the onset and progression of stroke.With a better understanding of the critical role of mitochondrial dysfunction modulations in post-stroke neurological injury,these modulations have emerged as a potential target for stroke prevention and treatment.Additionally,since effective treatments for stroke are extremely limited and natural products currently offer some outstanding advantages,we focused on the findings and mechanisms of action related to the use of natural products for targeting mitochondrial dysfunction in the treatment of stroke.Natural products achieve neuroprotective through multi-target regulation of mitochondrial dysfunction encompassing the following processes:(1)Mitochondrial biogenesis:Cordyceps and hydroxysafflor yellow A activate the peroxisome proliferator-activated receptor gamma coactivator 1-alpha/nuclear respiratory factor pathway,promote mitochondrial DNA replication and respiratory chain protein synthesis,and thereby restore energy supply in the ischemic penumbra.(2)Mitochondrial dynamics balance:Ginsenoside Rb3 promotes Opa1-mediated neural stem cell migration and diffusion for recovery of damaged brain tissue.(3)Mitochondrial autophagy:Gypenoside XVII selectively eliminates damaged mitochondria via the phosphatase and tensin homolog-induced kinase 1/Parkin pathway and blocks reactive oxygen species and the NOD-like receptor protein 3 inflammasome cascade,thereby alleviating blood-brain barrier damage.(4)Anti-apoptotic mechanisms:Ginkgolide K inhibits Bax mitochondrial translocation and downregulates caspase-3/9 activity,reducing neuronal programmed death induced by ischemia-reperfusion.(5)Oxidative stress regulation:Scutellarin exerts antioxidant properties and improves neurological function by modulating the extracellular signal-regulated kinase 5-Kruppel-like factor 2-endothelial nitric oxide synthase signaling pathway.(6)Intercellular mitochondrial transport:Neuroprotective effects of Chrysophanol are associated with accelerated mitochondrial transfer from astrocytes to neurons.Existing studies have confirmed that natural products exhibit neuroprotective effects through multidimensional interventions targeting mitochondrial dysfunction in both ischemic and hemorrhagic stroke models.However,their clinical translation still faces challenges,such as the difficulty in standardization due to component complexity,insufficient cross-regional clinical data,and the lack of long-term safety evaluations.Future research should aim to integrate new technologies,such as single-cell sequencing and organoid models,to deeply explore the mitochondria-targeting mechanisms of natural products and validate their efficacy through multicenter clinical trials,providing theoretical support and translational pathways for the development of novel anti-stroke drugs.展开更多
Vibrations or dither's are features of the PWM servo control system in their steady outputs. On the grounds of analyses and experiments of a PWM pneumatic servo control system, the paper puts forward four varietie...Vibrations or dither's are features of the PWM servo control system in their steady outputs. On the grounds of analyses and experiments of a PWM pneumatic servo control system, the paper puts forward four varieties of PWM modulation methods, and concludes on the relationship between dithers and the different methods, and then discusses the influence of friction to the dithers. Results from experiments regarding the dynamic and static responses on the given system support the theories presented.展开更多
In this paper, a voltage oriented control strategy for three-level PWM rectifier based on Sliding Mode Control (SMC) is introduced in order to obtain fast and accurate response of dc-bus voltage. To verify the validit...In this paper, a voltage oriented control strategy for three-level PWM rectifier based on Sliding Mode Control (SMC) is introduced in order to obtain fast and accurate response of dc-bus voltage. To verify the validity of the analysis and the feasibility of the proposed control method a set of simulation tests have been conducted using Matlab/Simulink. The simulation results show that compared to the conventional PI controller, the SMC can reduce drastically the three-level rectifier’s voltage fluctuation and improve the dynamic response of dc-bus significantly.展开更多
基金National Natural Science Foundation of China(12405168)The Fundamental Research Funds for the Central Universities,China(2024CDJXY004)。
文摘[Background]High harmonic cavities are widely used in electron storage rings to lengthen thebunch,lower the bunch peak current,thereby reducing the IBS effect,enhancing the Touschek lifetime,as well asproviding Landau damping,which is particularly important for storage rings operating with ultra-low emittance or atlow beam energy.[Purpose]To further increase the bunch length without additional hardware costs,the phasemodulation in a dual-RF system is considered.[Methods]In this paper,turn-by-turn simulations incorporating randomsynchrotron radiation excitation are conducted,and a brief analysis is presented to explain the bunch lengtheningmechanism.[Results]Simulation results reveal that the peak current can be further reduced,thereby mitigating IBSeffects and enhancing the Touschek lifetime.Although the energy spread increases,which tends to reduce thebrightness of higher-harmonic radiation from the undulator,the brightness of the fundamental harmonic can,in fact,beimproved.
基金funding from the National Key Research and Development Program of China(No.2018YFE0110000)the National Natural Science Foundation of China(No.11274259,No.11574258)the Science and Technology Commission Foundation of Shanghai(21DZ1205500)in support of the present research.
文摘While reinforcement learning-based underwater acoustic adaptive modulation shows promise for enabling environment-adaptive communication as supported by extensive simulation-based research,its practical performance remains underexplored in field investigations.To evaluate the practical applicability of this emerging technique in adverse shallow sea channels,a field experiment was conducted using three communication modes:orthogonal frequency division multiplexing(OFDM),M-ary frequency-shift keying(MFSK),and direct sequence spread spectrum(DSSS)for reinforcement learning-driven adaptive modulation.Specifically,a Q-learning method is used to select the optimal modulation mode according to the channel quality quantified by signal-to-noise ratio,multipath spread length,and Doppler frequency offset.Experimental results demonstrate that the reinforcement learning-based adaptive modulation scheme outperformed fixed threshold detection in terms of total throughput and average bit error rate,surpassing conventional adaptive modulation strategies.
基金supported by the National Natural Science Foundation of China,No.82204663(to TZ)the Natural Science Foundation of Shandong Province,No.ZR2022QH058(to TZ).
文摘Modulations of mitochondrial dysfunction,which involve a series of dynamic processes such as mitochondrial biogenesis,mitochondrial fusion and fission,mitochondrial transport,mitochondrial autophagy,mitochondrial apoptosis,and oxidative stress,play an important role in the onset and progression of stroke.With a better understanding of the critical role of mitochondrial dysfunction modulations in post-stroke neurological injury,these modulations have emerged as a potential target for stroke prevention and treatment.Additionally,since effective treatments for stroke are extremely limited and natural products currently offer some outstanding advantages,we focused on the findings and mechanisms of action related to the use of natural products for targeting mitochondrial dysfunction in the treatment of stroke.Natural products achieve neuroprotective through multi-target regulation of mitochondrial dysfunction encompassing the following processes:(1)Mitochondrial biogenesis:Cordyceps and hydroxysafflor yellow A activate the peroxisome proliferator-activated receptor gamma coactivator 1-alpha/nuclear respiratory factor pathway,promote mitochondrial DNA replication and respiratory chain protein synthesis,and thereby restore energy supply in the ischemic penumbra.(2)Mitochondrial dynamics balance:Ginsenoside Rb3 promotes Opa1-mediated neural stem cell migration and diffusion for recovery of damaged brain tissue.(3)Mitochondrial autophagy:Gypenoside XVII selectively eliminates damaged mitochondria via the phosphatase and tensin homolog-induced kinase 1/Parkin pathway and blocks reactive oxygen species and the NOD-like receptor protein 3 inflammasome cascade,thereby alleviating blood-brain barrier damage.(4)Anti-apoptotic mechanisms:Ginkgolide K inhibits Bax mitochondrial translocation and downregulates caspase-3/9 activity,reducing neuronal programmed death induced by ischemia-reperfusion.(5)Oxidative stress regulation:Scutellarin exerts antioxidant properties and improves neurological function by modulating the extracellular signal-regulated kinase 5-Kruppel-like factor 2-endothelial nitric oxide synthase signaling pathway.(6)Intercellular mitochondrial transport:Neuroprotective effects of Chrysophanol are associated with accelerated mitochondrial transfer from astrocytes to neurons.Existing studies have confirmed that natural products exhibit neuroprotective effects through multidimensional interventions targeting mitochondrial dysfunction in both ischemic and hemorrhagic stroke models.However,their clinical translation still faces challenges,such as the difficulty in standardization due to component complexity,insufficient cross-regional clinical data,and the lack of long-term safety evaluations.Future research should aim to integrate new technologies,such as single-cell sequencing and organoid models,to deeply explore the mitochondria-targeting mechanisms of natural products and validate their efficacy through multicenter clinical trials,providing theoretical support and translational pathways for the development of novel anti-stroke drugs.
文摘Vibrations or dither's are features of the PWM servo control system in their steady outputs. On the grounds of analyses and experiments of a PWM pneumatic servo control system, the paper puts forward four varieties of PWM modulation methods, and concludes on the relationship between dithers and the different methods, and then discusses the influence of friction to the dithers. Results from experiments regarding the dynamic and static responses on the given system support the theories presented.
文摘In this paper, a voltage oriented control strategy for three-level PWM rectifier based on Sliding Mode Control (SMC) is introduced in order to obtain fast and accurate response of dc-bus voltage. To verify the validity of the analysis and the feasibility of the proposed control method a set of simulation tests have been conducted using Matlab/Simulink. The simulation results show that compared to the conventional PI controller, the SMC can reduce drastically the three-level rectifier’s voltage fluctuation and improve the dynamic response of dc-bus significantly.
