In this paper, we have demonstrated an Er-doped ultrafast laser with a single mode fiber-gradient index multimode fiber-single mode fiber(SMF-GIMF-SMF, SMS) structure as saturable absorber(SA), which can generate not ...In this paper, we have demonstrated an Er-doped ultrafast laser with a single mode fiber-gradient index multimode fiber-single mode fiber(SMF-GIMF-SMF, SMS) structure as saturable absorber(SA), which can generate not only stable single-pulse state, but also special mode-locked pulses with the characteristics of high energy and noisy behaviors at proper pump power and cavity polarization state. In addition, we have deeply investigated the real-time spectral evolutions of the mode-locked pulses through the dispersive Fourier transformation(DFT) technique. It can be found that the pulse regime can actually consist of a lot of small noise pulses with randomly varying intensities. We believe that these results will further enrich the nonlinear dynamical processes in the ultrafast lasers.展开更多
A diode dual-end-pumped Nd：YVO4 regenerative amplifier is reported. The influence of the cavity stability on the performance of the regenerative amplifier is studied. The experimental results match well with the anal...A diode dual-end-pumped Nd：YVO4 regenerative amplifier is reported. The influence of the cavity stability on the performance of the regenerative amplifier is studied. The experimental results match well with the analysis at high pump power. The mode locking seed pulses with 15 ps pulse width and 10 nJ single pulse energy at 86 MHz are amplified up to 4.7 mJ at 1 kHz, corresponding to the maximum amplification about 0.5 x 106, by our regenerative amplifier. And an average power of 4.7 W is obtained at the repetition rate from 1 kHz to 10 kHz.展开更多
BACKGROUND Alzheimer's disease(AD),characterized by the ongoing deterioration of neural function,often presents alongside depressive features and greatly affects the quality of life of individuals living with the ...BACKGROUND Alzheimer's disease(AD),characterized by the ongoing deterioration of neural function,often presents alongside depressive features and greatly affects the quality of life of individuals living with the condition.Although several treatment methods exist,their efficacy is limited.In recent years,repetitive transcranial magnetic stimulation(rTMS)utilizing the theta burst stimulation(TBS)mode,specifically the intermittent TBS(iTBS),has demonstrated promising therapeutic potential in the management of neuropsychiatric disorders.AIM To examine the therapeutic efficacy of iTBS mode of rTMS for treating depressive symptoms in patients with AD.METHODS This retrospective study enrolled 105 individuals diagnosed with AD with depressive symptoms at Huzhou Third Municipal Hospital,affiliated with Huzhou University,between January 2020 and December 2023.Participants received standard pharmacological interventions and were categorized into control(n=53)and observation(n=52)groups based on treatment protocols.The observation group received iTBS mode of rTMS,while the control group received pseudo-stimulation.A comparative analysis evaluated psychological well-being,adverse events,and therapeutic at initiation of hospitalization(T0)and 15 days post-treatment(T1).RESULTS At T1,both groups exhibited a marked reduction in self-rating depression scale and Hamilton depression scale scores compared to T0.Furthermore,the observa-tion group showed a more pronounced decrease than the control group.By T1,the Mini-mental state examination scores for both groups had increased markedly from their initial T0 assessments.Importantly,the increase was particularly more substantial in the observation group than in the control group.Fourteen patients in the control group had ineffective treatment effects,while five patients in the observation group experienced the same.Additionally,the observation group experienced a substantially reduced incidence of ineffective treatment as compared to the control group(both P<0.05);there were no recorded serious adverse events in either group.CONCLUSION The iTBS model of rTMS effectively treated AD with depression,improving depressive symptoms and cognitive function in patients without serious adverse reactions,warranting clinical consideration.展开更多
Through using a direct-current driven plasma jet operated underwater,degradation of methylene blue(MB)is investigated with air and oxygen used as working gases.With a low power voltage,a plasma plume extends from the ...Through using a direct-current driven plasma jet operated underwater,degradation of methylene blue(MB)is investigated with air and oxygen used as working gases.With a low power voltage,a plasma plume extends from the needle electrode,which is purple in air.It turns pink after it bridges the two electrodes.During the process,oxygen plasma remains white.Discharge operates in a pulsed mode or a continuous one,which depends on the magnitude of power voltage.For the pulsed mode,oxygen discharge has a shorter plume and a higher pulse frequency than air discharge under the same power voltage.For the same current of the continuous mode,both power and gap voltages of oxygen discharge are higher than those of air discharge.Moreover,MB degradation efficiency increases with increasing power voltage or initial concentration of MB solution.Compared with air discharge,oxygen discharge has a higher degradation efficiency with the same power voltage and treatment time.The pulsed oxygen discharge with power voltage of about 6.5 k V has the highest efficiency in degrading MB dye,reaching approximately 85.8%after 10 min treatment.As a comparison,after 10 min treatment in air discharge,the highest degradation efficiency is 63.7%,which appears in the continuous mode at a power voltage of 10.6 kV.Besides,optical spectra from the discharges are also compared for the two types of working gases.展开更多
This study concerns a Ka-band solid-state transmitter cloud radar, made in China, which can operate in three different work modes, with different pulse widths, and coherent and incoherent integration numbers, to meet ...This study concerns a Ka-band solid-state transmitter cloud radar, made in China, which can operate in three different work modes, with different pulse widths, and coherent and incoherent integration numbers, to meet the requirements for cloud remote sensing over the Tibetan Plateau. Specifically, the design of the three operational modes of the radar（i.e., boundary mode M1, cirrus mode M2, and precipitation mode M3） is introduced. Also, a cloud radar data merging algorithm for the three modes is proposed. Using one month＇s continuous measurements during summertime at Naqu on the Tibetan Plateau,we analyzed the consistency between the cloud radar measurements of the three modes. The number of occurrences of radar detections of hydrometeors and the percentage contributions of the different modes＇ data to the merged data were estimated.The performance of the merging algorithm was evaluated. The results indicated that the minimum detectable reflectivity for each mode was consistent with theoretical results. Merged data provided measurements with a minimum reflectivity of -35 dBZ at the height of 5 km, and obtained information above the height of 0.2 km. Measurements of radial velocity by the three operational modes agreed very well, and systematic errors in measurements of reflectivity were less than 2 dB. However,large discrepancies existed in the measurements of the linear depolarization ratio taken from the different operational modes.The percentage of radar detections of hydrometeors in mid- and high-level clouds increased by 60% through application of pulse compression techniques. In conclusion, the merged data are appropriate for cloud and precipitation studies over the Tibetan Plateau.展开更多
The complexation of Cd with cysteine has been investigated at pH ~9, and in constant ionic medium 0.59 M NaNO3 and borate buffer. Reduction signals of the hydrated Cd2+ and Cd-cysteinate complex were resolved on the p...The complexation of Cd with cysteine has been investigated at pH ~9, and in constant ionic medium 0.59 M NaNO3 and borate buffer. Reduction signals of the hydrated Cd2+ and Cd-cysteinate complex were resolved on the potential scale during amperometric titration of 2 × 10-6 M Cd2+ with cysteine and cysteine with Cd2+, in a differential pulse (DP) mode on HMDE. The 1:1 molar ratio of Cd2+ to cysteine, and cysteine to Cd2+, was defined for Cd-cysteinate complex formed under the defined conditions. The appearance of the prepeak on the Cd-cysteinate reduction signal is showed, as the result of cysteine adsorption in reduced form. From the mass balance equations, the stoichiometric stability constants of Cd-cysteinate complex were calculated. Under various experimental conditions, comparable log K values were obtained. The grand average log K = 7.83 M-1 refers to 0.59 M ionic strength and 23℃.展开更多
Femtosecond laser ablation-driven periodic surface structuring offers a promising method for large-scale and high-throughput nanolithography technique.However,the self-organized periodic structures typically manifest ...Femtosecond laser ablation-driven periodic surface structuring offers a promising method for large-scale and high-throughput nanolithography technique.However,the self-organized periodic structures typically manifest constraints in terms of tunable period and depth,as well as suboptimal regularity,which restricts their broader application potential.Here,in terms of a rarely explored laser-induced photochemical mechanism for nonablative structuring,we demonstrate manufacturing of sub-wavelength oxidative grating structures on silicon films with active structural modulation.In this scenario,the plasmonic field plays a pivotal role in dragging oxygen ions from surface into the silicon,greatly speeding up oxidation rates.While high oxygen doping levels can already be achieved with single-pulse exposure,far superior results are obtained with the application of 40-MHz burst mode pulse trains,mitigating the formation of excessively large nanocrystallites.Furthermore,it is revealed that the periodicity and modulation depth of laser-writing nanograting are both dependent on the number of pulse per burst.This offers a convenient scheme for actively controlling laser plasmonic lithography.展开更多
To date,the vast majority of ultrafast laser applications require a stable,unvarying,mode-locked pulsed output.Meanwhile,each year,laser research groups report multitudes of original ultrafast dynamics accessible from...To date,the vast majority of ultrafast laser applications require a stable,unvarying,mode-locked pulsed output.Meanwhile,each year,laser research groups report multitudes of original ultrafast dynamics accessible from relatively standard laser architectures.The richness and universality of ultrafast laser dynamics hinge on the diversity of multiple-pulse regimes combined with a large range of bifurcations.展开更多
In this paper, different electrical measurement and operation methods of resistive random access memory （RRAM） have been summarized, including voltage sweeping mode （VSM）, current sweeping mode （CSM）, co lstant ...In this paper, different electrical measurement and operation methods of resistive random access memory （RRAM） have been summarized, including voltage sweeping mode （VSM）, current sweeping mode （CSM）, co lstant current stress （CCS）, constant voltage stress （CVS）, rectangular pulse mode （RPM）, and triangle pulse mode （TPM）. Meanwhile, the effects of these meas- urement methods on the forming, set, reset and read operation as well as endurance performance have been compared. Finally, their respective controllability of various resistive switching parameters have been summar zeal and analyzed.展开更多
The mitigation of dephasing poses a significant challenge toimproving the performance of error-prone superconducting quantum computing systems.Here,the dephasing of a transmon qubit ina dispersive readout regime was i...The mitigation of dephasing poses a significant challenge toimproving the performance of error-prone superconducting quantum computing systems.Here,the dephasing of a transmon qubit ina dispersive readout regime was investigated by adopting aJosephson traveling-wave parametric amplifier as the preamplifier.Our findings reveal that the potent pump leakage from the preamplifier may lead to severe dephasing.This could be attributed to amixture of measurement-induced dephasing,ac Stark effect,andheating.It is showed that pulse-mode readout is a promising measurement scheme to mitigate qubit dephasing while minimizing theneed for bulky circulators.Our work provides key insights intomitigating decoherence from microwave-pumped preamplifiers,which will be critical for advancing large-scale quantum computers.展开更多
基金supported by the Guangdong Basic and Applied Basic Research Foundation (No.2023A1515010093)the Shenzhen Fundamental Research Program (Stable Support Plan Program)(Nos.JCYJ20220809170611004, 20231121110828001 and 20231121113641002)the National Taipei University of Technology-Shenzhen University Joint Research Program (No.2024001)。
文摘In this paper, we have demonstrated an Er-doped ultrafast laser with a single mode fiber-gradient index multimode fiber-single mode fiber(SMF-GIMF-SMF, SMS) structure as saturable absorber(SA), which can generate not only stable single-pulse state, but also special mode-locked pulses with the characteristics of high energy and noisy behaviors at proper pump power and cavity polarization state. In addition, we have deeply investigated the real-time spectral evolutions of the mode-locked pulses through the dispersive Fourier transformation(DFT) technique. It can be found that the pulse regime can actually consist of a lot of small noise pulses with randomly varying intensities. We believe that these results will further enrich the nonlinear dynamical processes in the ultrafast lasers.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 50721004 and 60978032)
文摘A diode dual-end-pumped Nd：YVO4 regenerative amplifier is reported. The influence of the cavity stability on the performance of the regenerative amplifier is studied. The experimental results match well with the analysis at high pump power. The mode locking seed pulses with 15 ps pulse width and 10 nJ single pulse energy at 86 MHz are amplified up to 4.7 mJ at 1 kHz, corresponding to the maximum amplification about 0.5 x 106, by our regenerative amplifier. And an average power of 4.7 W is obtained at the repetition rate from 1 kHz to 10 kHz.
基金Huzhou Science and Technology Plan Project,No.2019GZ38.
文摘BACKGROUND Alzheimer's disease(AD),characterized by the ongoing deterioration of neural function,often presents alongside depressive features and greatly affects the quality of life of individuals living with the condition.Although several treatment methods exist,their efficacy is limited.In recent years,repetitive transcranial magnetic stimulation(rTMS)utilizing the theta burst stimulation(TBS)mode,specifically the intermittent TBS(iTBS),has demonstrated promising therapeutic potential in the management of neuropsychiatric disorders.AIM To examine the therapeutic efficacy of iTBS mode of rTMS for treating depressive symptoms in patients with AD.METHODS This retrospective study enrolled 105 individuals diagnosed with AD with depressive symptoms at Huzhou Third Municipal Hospital,affiliated with Huzhou University,between January 2020 and December 2023.Participants received standard pharmacological interventions and were categorized into control(n=53)and observation(n=52)groups based on treatment protocols.The observation group received iTBS mode of rTMS,while the control group received pseudo-stimulation.A comparative analysis evaluated psychological well-being,adverse events,and therapeutic at initiation of hospitalization(T0)and 15 days post-treatment(T1).RESULTS At T1,both groups exhibited a marked reduction in self-rating depression scale and Hamilton depression scale scores compared to T0.Furthermore,the observa-tion group showed a more pronounced decrease than the control group.By T1,the Mini-mental state examination scores for both groups had increased markedly from their initial T0 assessments.Importantly,the increase was particularly more substantial in the observation group than in the control group.Fourteen patients in the control group had ineffective treatment effects,while five patients in the observation group experienced the same.Additionally,the observation group experienced a substantially reduced incidence of ineffective treatment as compared to the control group(both P<0.05);there were no recorded serious adverse events in either group.CONCLUSION The iTBS model of rTMS effectively treated AD with depression,improving depressive symptoms and cognitive function in patients without serious adverse reactions,warranting clinical consideration.
基金sponsored by National Natural Science Foundation of China (Nos. 11875121,11575050 and 51977057)the Midwest Universities Comprehensive Strength Promotion Project+3 种基金the Natural Science Foundation of Hebei Province,China (Nos. A2019201100 and A2016201042)College Hundred Outstanding Innovative Talent Support Program of Hebei Education Bureau (No. SLRC2017021)the 333 Talents Project of Hebei province,China (No. A2016005005)Post-graduate’s Innovation Fund Project of Hebei Province(Nos. CXZZBS2019023 and CXZZBS2019029)。
文摘Through using a direct-current driven plasma jet operated underwater,degradation of methylene blue(MB)is investigated with air and oxygen used as working gases.With a low power voltage,a plasma plume extends from the needle electrode,which is purple in air.It turns pink after it bridges the two electrodes.During the process,oxygen plasma remains white.Discharge operates in a pulsed mode or a continuous one,which depends on the magnitude of power voltage.For the pulsed mode,oxygen discharge has a shorter plume and a higher pulse frequency than air discharge under the same power voltage.For the same current of the continuous mode,both power and gap voltages of oxygen discharge are higher than those of air discharge.Moreover,MB degradation efficiency increases with increasing power voltage or initial concentration of MB solution.Compared with air discharge,oxygen discharge has a higher degradation efficiency with the same power voltage and treatment time.The pulsed oxygen discharge with power voltage of about 6.5 k V has the highest efficiency in degrading MB dye,reaching approximately 85.8%after 10 min treatment.As a comparison,after 10 min treatment in air discharge,the highest degradation efficiency is 63.7%,which appears in the continuous mode at a power voltage of 10.6 kV.Besides,optical spectra from the discharges are also compared for the two types of working gases.
基金funded by the National Sciences Foundation of China(Grant No.91337103)the China Meteorological Administration Special Public Welfare Research Fund(Grant No.GYHY201406001)
文摘This study concerns a Ka-band solid-state transmitter cloud radar, made in China, which can operate in three different work modes, with different pulse widths, and coherent and incoherent integration numbers, to meet the requirements for cloud remote sensing over the Tibetan Plateau. Specifically, the design of the three operational modes of the radar（i.e., boundary mode M1, cirrus mode M2, and precipitation mode M3） is introduced. Also, a cloud radar data merging algorithm for the three modes is proposed. Using one month＇s continuous measurements during summertime at Naqu on the Tibetan Plateau,we analyzed the consistency between the cloud radar measurements of the three modes. The number of occurrences of radar detections of hydrometeors and the percentage contributions of the different modes＇ data to the merged data were estimated.The performance of the merging algorithm was evaluated. The results indicated that the minimum detectable reflectivity for each mode was consistent with theoretical results. Merged data provided measurements with a minimum reflectivity of -35 dBZ at the height of 5 km, and obtained information above the height of 0.2 km. Measurements of radial velocity by the three operational modes agreed very well, and systematic errors in measurements of reflectivity were less than 2 dB. However,large discrepancies existed in the measurements of the linear depolarization ratio taken from the different operational modes.The percentage of radar detections of hydrometeors in mid- and high-level clouds increased by 60% through application of pulse compression techniques. In conclusion, the merged data are appropriate for cloud and precipitation studies over the Tibetan Plateau.
文摘The complexation of Cd with cysteine has been investigated at pH ~9, and in constant ionic medium 0.59 M NaNO3 and borate buffer. Reduction signals of the hydrated Cd2+ and Cd-cysteinate complex were resolved on the potential scale during amperometric titration of 2 × 10-6 M Cd2+ with cysteine and cysteine with Cd2+, in a differential pulse (DP) mode on HMDE. The 1:1 molar ratio of Cd2+ to cysteine, and cysteine to Cd2+, was defined for Cd-cysteinate complex formed under the defined conditions. The appearance of the prepeak on the Cd-cysteinate reduction signal is showed, as the result of cysteine adsorption in reduced form. From the mass balance equations, the stoichiometric stability constants of Cd-cysteinate complex were calculated. Under various experimental conditions, comparable log K values were obtained. The grand average log K = 7.83 M-1 refers to 0.59 M ionic strength and 23℃.
基金supported by the National Natural Science Foundation of China(12474317 and 62105269).
文摘Femtosecond laser ablation-driven periodic surface structuring offers a promising method for large-scale and high-throughput nanolithography technique.However,the self-organized periodic structures typically manifest constraints in terms of tunable period and depth,as well as suboptimal regularity,which restricts their broader application potential.Here,in terms of a rarely explored laser-induced photochemical mechanism for nonablative structuring,we demonstrate manufacturing of sub-wavelength oxidative grating structures on silicon films with active structural modulation.In this scenario,the plasmonic field plays a pivotal role in dragging oxygen ions from surface into the silicon,greatly speeding up oxidation rates.While high oxygen doping levels can already be achieved with single-pulse exposure,far superior results are obtained with the application of 40-MHz burst mode pulse trains,mitigating the formation of excessively large nanocrystallites.Furthermore,it is revealed that the periodicity and modulation depth of laser-writing nanograting are both dependent on the number of pulse per burst.This offers a convenient scheme for actively controlling laser plasmonic lithography.
文摘To date,the vast majority of ultrafast laser applications require a stable,unvarying,mode-locked pulsed output.Meanwhile,each year,laser research groups report multitudes of original ultrafast dynamics accessible from relatively standard laser architectures.The richness and universality of ultrafast laser dynamics hinge on the diversity of multiple-pulse regimes combined with a large range of bifurcations.
基金supported by the National Natural Science Foundation of China(Grant Nos.61322408,61221004,61422407,61334007,61474136,61274091,61376112,61306117,61106119,and 61106082)National Basic Research Program of China(Grant No.2011CBA00602)National High Technology Research and Development Program of China(Grant Nos.2014AA032900,2013AA030801,2011AA010401 and 2011AA-010402)
文摘In this paper, different electrical measurement and operation methods of resistive random access memory （RRAM） have been summarized, including voltage sweeping mode （VSM）, current sweeping mode （CSM）, co lstant current stress （CCS）, constant voltage stress （CVS）, rectangular pulse mode （RPM）, and triangle pulse mode （TPM）. Meanwhile, the effects of these meas- urement methods on the forming, set, reset and read operation as well as endurance performance have been compared. Finally, their respective controllability of various resistive switching parameters have been summar zeal and analyzed.
基金supported by the National Natural Science Foundation of China(NSFC-11890704)the Natural Science Foundation of Beijing(NSFB-Z190012)the Key-Area Research and Development Program of Guangdong Province(Grant No.2018B030326001).
文摘The mitigation of dephasing poses a significant challenge toimproving the performance of error-prone superconducting quantum computing systems.Here,the dephasing of a transmon qubit ina dispersive readout regime was investigated by adopting aJosephson traveling-wave parametric amplifier as the preamplifier.Our findings reveal that the potent pump leakage from the preamplifier may lead to severe dephasing.This could be attributed to amixture of measurement-induced dephasing,ac Stark effect,andheating.It is showed that pulse-mode readout is a promising measurement scheme to mitigate qubit dephasing while minimizing theneed for bulky circulators.Our work provides key insights intomitigating decoherence from microwave-pumped preamplifiers,which will be critical for advancing large-scale quantum computers.
