Harmonic mode-locking(HML)in soliton fiber lasers is crucial for generating high-repetition-rate pulse trains beyond the fundamental cavity frequency,enabling advanced applications in,for example,optical communication...Harmonic mode-locking(HML)in soliton fiber lasers is crucial for generating high-repetition-rate pulse trains beyond the fundamental cavity frequency,enabling advanced applications in,for example,optical communication and precision sensing.However,achieving HML in experiments is challenging,owing to its inherent instability and high sensitivity to laser parameters,resulting in complex and iterative adjustments.In this paper,a novel HML technique utilizing bidirectional adjustment of pump power is proposed,and it is experimentally demonstrated in an all-fiber hybrid mode-locked soliton laser.By first increasing the pump power to generate a soliton bunch with a certain number of pulses and then gradually decreasing it,HML can be achieved at an order corresponding to the number of pulses in the soliton bunch.Experimental results on the evolution of temporal pulse trains during bidirectional adjustment of the pump power enable a relationship to be established between pump power and soliton bunching with increasing pump power,and reveal the collapse of the soliton bunch and subsequent gradual uniform distribution of solitons into an HML state with decreasing pump power.Second-to sixth-order HML is successfully generated using the proposed technique,and an analysis of the results provides a deeper understanding of the observed pulse dynamics.展开更多
We achieved an ultra-flat broad spectrum output with a 20-dB bandwidth of 77.85 nm in a double-clad Yb-doped fiber laser.The intensity difference between the highest and lowest points of the spectrum indicates a flatn...We achieved an ultra-flat broad spectrum output with a 20-dB bandwidth of 77.85 nm in a double-clad Yb-doped fiber laser.The intensity difference between the highest and lowest points of the spectrum indicates a flatness better than4 dB.More notably,this ultra-flat broad spectrum maintains a stable single-pulse mode-locking state.With the increase of pump power,an ultra-wide spectrum with a 20-dB bandwidth approaching 100 nm was formed at a pump power of 2.25 W.Additionally,we obtained a 9-pulse mode-locked state at another PC station with the same pump,which is the highest number of stable mode-locked pulse bursts observed so far with a first-order Raman frequency shift.This fiber laser shows its benefits of ultra-flat broad spectrum,high stability,and ease of fabrication,which provides a new method of obtaining the broadband light source for multiple practical applications.展开更多
An actively mode-locked Ho： YAG laser pumped by a diode-pumped Tin-doped fiber laser is reported. For the cw operation, we obtain the maximum output power of 3.43 W with a central wavelength 2022.2nm at the maximum i...An actively mode-locked Ho： YAG laser pumped by a diode-pumped Tin-doped fiber laser is reported. For the cw operation, we obtain the maximum output power of 3.43 W with a central wavelength 2022.2nm at the maximum incident pump power of 11.4 W, corresponding to a slope efficiency of 34.5%. The beam quality factor M2 is 1.16, and the output beam is close to fundamental TEMoo. In the case of the CWML operation, a stable pulse train is generated with an average output power up to 3.41 W with a slope efficiency of 34.3% at the incident pump power of 11.4 W and a pulse duration of 294ps at a repetition rate of 81.92MHz. In addition, the maximum single pulse energy is 41.6nJ.展开更多
In the last few years,research on advanced ultrafast photonic devices has attracted great interest from laser physicists.As a semiconductor material with excellent nonlinear saturation absorption characteristics,Ga As...In the last few years,research on advanced ultrafast photonic devices has attracted great interest from laser physicists.As a semiconductor material with excellent nonlinear saturation absorption characteristics,Ga As has been used in solidstate and fiber lasers as a mode-locker.However,the pulse widths that have been reported in the searchable published literature are all long and the shortest is tens of picoseconds.Femtosecond pulse widths,desired for a variety of applications,have not yet been reported in Ga As-based pulsed lasers.In this work,we further explore the nonlinear characteristics of Ga As that has been magnetron sputtered onto the surface of a tapered fiber and its application in the generation of femtosecond lasing via effective dispersion optimization and nonlinearity management.With the enhanced interaction between evanescent waves and Ga As nanosheets,mode-locked soliton pulses as short as 830 fs are generated at repetition rates of 4.64 MHz.As far as we know,this is the first time that femtosecond-level pulses have been generated with a Ga As-based saturable absorber.In addition,soliton molecules,including in the dual-pulse state,are also realized under stronger pumping.This work demonstrates that Ga As-based photonic devices have good application prospects in effective polymorphous ultrashort pulsed laser generation.展开更多
We designed and investigated a passive synchronized mode-locked fiber laser.The device utilizes a dual-cavity structure driven by the nonlinear polarization rotation(NPR)mechanism.Stable mode-locking is attained by sy...We designed and investigated a passive synchronized mode-locked fiber laser.The device utilizes a dual-cavity structure driven by the nonlinear polarization rotation(NPR)mechanism.Stable mode-locking is attained by synergistically controlling gain,polarization state,and optical path length in two symmetric sub-cavities.Experiments proved that repetition rate of the sub-cavities can be adjusted via the time delay line(TDL)to achieve synchronized mode-locking.The system stably generates multi-wavelength pulses at a single repetition frequency,evidenced by multiple spectral peaks and equidistant pulse sequences.These findings facilitate the development of high-performance multi-wavelength ultrashort pulse sources,crucial for optical communications,spectral analysis,and remote sensing.展开更多
new heterocyclic dipeptide with a highly functionalized 1,2-oxazadecaline core,named trichodermamide H(1),and three known analogues,along with three known polyketides,were isolated from the fermentation extract of the...new heterocyclic dipeptide with a highly functionalized 1,2-oxazadecaline core,named trichodermamide H(1),and three known analogues,along with three known polyketides,were isolated from the fermentation extract of the mangrovederived fungus Penicillium janthinellum XLN32122.The structure of 1 was elucidated on the basis of extensive 1D and 2D NMR spectra data analysis,HR-ESI-MS,electronic circular dichroism(ECD)calculations.Trichodermamide B(3)exhibited better inhibitory effect on nitric oxide(NO)production in lipopolysaccharide(LPS)induced RAW 264.7 cells with an IC_(50)value of(13.13±0.005)μmol/L than that of the positive control dexamethasone[IC_(50)=(136.84±1.33)μmol/L].Compound 3 exhibited antibacterial activity against methicillin-resistant Staphylococcus aureus(MRSA)with an IC_(50)value of 12.5μg/mL,while the positive control vancomycin showed an IC_(50)value of 1.563μg/mL.展开更多
Lithium–sulfur(Li–S)batteries are promisingcandidates for next-generation energy storagegiven their high energy density and potential low cost.Chemically activated carbon(CAC)is often used fortheir cathodes,because ...Lithium–sulfur(Li–S)batteries are promisingcandidates for next-generation energy storagegiven their high energy density and potential low cost.Chemically activated carbon(CAC)is often used fortheir cathodes,because it has a high specific surfacearea for sulfur loading.We have developed a pressurizedphysical activation(PPA)method that producedan activated carbon(PPAC)with a high specific surfacearea comparable to that of CAC.The pore structure of PPAC could be changed and its use as a cathode material for Li–Sbatteries was investigated.Battery tests at different capacity rates(C-rates)showed that it had a much improved high-rate performancewith a discharge capacity of 900 mAh/(g of sulfur)at 1 C,in contrast to only 600 mAh/(g of sulfur)for CAC.Porestructure analyses showed that PPAC prepared at a high activation temperature(1000℃)had unusual channel-like mesoporesbetween the microdomains that are the basic structural units of artificial carbon materials.These are connected to microporesdeveloped in each microdomain,and deliver ions from the surroundings to the internal pores and vice versa.The well-developedmicropores and mesopores of PPAC respectively ensured the high adsorption of lithium polysulfides and a high rate ofion diffusion.Compared to CAC,PPAC is a high-performance,low-cost cathode material that is promising for use in futureLi–S batteries.展开更多
The supercontinuum (SC) generation at the repetition rate of 10 GHz is presented. The SC is generated in a 4.2 km conventional dispersion-shifted fiber ( DSF), which is produced with nonlinear effects and group veloci...The supercontinuum (SC) generation at the repetition rate of 10 GHz is presented. The SC is generated in a 4.2 km conventional dispersion-shifted fiber ( DSF), which is produced with nonlinear effects and group velocity dispersion. The DSF is pumped by an actively mode-locked Er3+ -doped fiber laser with pulse width of 7.97 ps. A novel SC pulse source with a bandwidth up to 125 nm is obtained, which covers the whole C, L bands and part of S band. The stable, narrow pulses with mean pulse-width of 9.7 ps and time-bandwidth product of 0.48 are filtered out across the whole SC bandwidth. This supercontinuum pulse source is suitable for future high-speed optical communications.展开更多
The pulse generation from active mode-locking terahertz quantum cascade laser is studied by Maxwell-Bloch equations.It is shown that longer dephasing time will lead to multiple pulses generation from the laser.The dep...The pulse generation from active mode-locking terahertz quantum cascade laser is studied by Maxwell-Bloch equations.It is shown that longer dephasing time will lead to multiple pulses generation from the laser.The dependence of output field on modulation length and radio-frequency parameters is obtained.In order to achieve short pulse generation,the DC bias should close to threshold value and modulation length should be shorter than 0.256 mm.The output pulse is unstable and the envelope shows many oscillations in the presence of spatial hole burning,resulting destabilization of mode-locking.展开更多
A modified multiwavelength actively mode-locked fiber ring laser is proposed and experimentally demonstrated. In this kind of laser, stable multiwavelengths lasing is achieved by integrating cascaded sampled fiber Bra...A modified multiwavelength actively mode-locked fiber ring laser is proposed and experimentally demonstrated. In this kind of laser, stable multiwavelengths lasing is achieved by integrating cascaded sampled fiber Bragg gratings(SFBGs) into the laser cavity. To implement actively mode-locking technique, a double-ring cavity configuration is used to assure that the cavity lengths for all wavelengths lasing are identical. Thus, simultaneous mode locking of all wavelengths has been successfully achieved by using the same mode-locking signal.展开更多
Two new linear furocoumarins were isolated from Notopterygium incisum using silica gel,gel Sephadex LH-20 column chromatography,and preparative high-performance liquid chromatography.The structures of the new compound...Two new linear furocoumarins were isolated from Notopterygium incisum using silica gel,gel Sephadex LH-20 column chromatography,and preparative high-performance liquid chromatography.The structures of the new compounds were elucidated through analysis of spectroscopic evidence,including data obtained from high-resolution electrospray ionization mass spectrometry(HRESIMS)and nuclear magnetic resonance(NMR).The absolute configurations of Notoprenylate L(1)and Nototerprinol K(2)were further confirmed using electronic circular dichroism(ECD)calculations.Compound 1 demonstrated the ability to inhibit the expression of nitric oxide(NO),a pro-inflammatory factor,in lipopolysaccharide-induced RAW264.7 macrophages at a concentration of 7.5μmol/L,indicating its potential for anti-inflammatory activity.展开更多
Two Co(Ⅱ)and Ni(Ⅱ)complexes were synthesized by synergistic coordination of 3,3-diphenylpropionic acid(HDPA)and 2,2′-bipyridylamine(PAm).The structures of complexes[Co(DPA)_(2)(PAm)]·2H_(2)O(1)and[Ni(DPA)_(2)(...Two Co(Ⅱ)and Ni(Ⅱ)complexes were synthesized by synergistic coordination of 3,3-diphenylpropionic acid(HDPA)and 2,2′-bipyridylamine(PAm).The structures of complexes[Co(DPA)_(2)(PAm)]·2H_(2)O(1)and[Ni(DPA)_(2)(PAm)]·2H_(2)O(2)were determined by single-crystal X-ray diffraction,IR spectroscopy,and powder X-ray diffraction.Hirshfeld surface analysis provided quantitative insights into the intermolecular interactions within the complexes,while molecular docking studies elucidated their binding modes and affinities toward urease.Furthermore,the biological activities of both complexes were systematically evaluated through a range of assays,including DNA binding,urease inhibition,antibacterial activity,and in vitro cytotoxicity against cancer cells.Both complexes exhibited binding affinity for DNA and displayed notable urease inhibitory activity.Under in vitro conditions,both complexes showed appreciable cytotoxicity toward HepG2 cells with efficacy comparable to clinically used platinumbased anticancer agents.CCDC:2479943,1;2479944,2.展开更多
Passiflora incarnata L.,commonly known as passionflower,is traditionally cultivated as an ornamental plant but has demonstrated diverse therapeutic potential.Its pharmacological effects are attributed to bioactive com...Passiflora incarnata L.,commonly known as passionflower,is traditionally cultivated as an ornamental plant but has demonstrated diverse therapeutic potential.Its pharmacological effects are attributed to bioactive compounds such as flavonoids and alkaloids,which influence multiple biological pathways.This review aims to summarise and critically analyse recent findings on the pharmacological properties of Passiflora incarnata L.,focusing on its neuropsychiatric,antioxidant,antimicrobial,and anticancer activities.A targeted literature search was conducted in PubMed,Scopus,Web of Science,and Google Scholar for peer-reviewed publications between 2000 to 2025.Relevant articles were screened,and a more appropriate article related to the objective of the review was selected.Some classical papers are also cited as per the requirement of the topic.Passiflora incarnata L.showed multifunctional medicinal properties with various applications in neuropsychiatry,oxidative stress management,antimicrobial agent,and as an anticancer agent.The U.S.Food and Drug Administration categorizes passionflower extracts as“generally recognized as safe”.However,most evidence remains preclinical,with methodological variation limiting generalisation.Standardised formulation,robust clinical trials,and in-depth in vivo studies are essential to establish its therapeutic relevance and safety in modern medicine.展开更多
To address the longstanding challenge in traditional carborane methodology of rapidly and efficiently constructing carboranyl-based polycyclic frameworks,Pd-catalyzed one-pot reactions between pyridyl-substituted nido...To address the longstanding challenge in traditional carborane methodology of rapidly and efficiently constructing carboranyl-based polycyclic frameworks,Pd-catalyzed one-pot reactions between pyridyl-substituted nidocarboranes and alkynes directly afford two distinct types of 2D-3D fused carboranyl polycyclic compounds:3a-3f,4a-4d.The structures of this series of compounds were characterized by nuclear magnetic resonance spectroscopy,single-crystal X-ray diffraction,and high-resolution mass spectrometry,and a plausible reaction mechanism was proposed.Crystal structures reveal that the multiple rings in such 2D-3D fused carboranyl polycyclic compounds exhibit a certain degree of coplanarity.Furthermore,these compounds exhibited properties distinct from those of conventional 2D polycyclic systems.CCDC:2481988,3c,2481990,3f,2481986,4d.展开更多
This study investigates prescribed-time position tracking control for electromagnetic satellite formations subject to model uncertainties and external disturbances.Using the Clohessy-Wiltshire equations as the relativ...This study investigates prescribed-time position tracking control for electromagnetic satellite formations subject to model uncertainties and external disturbances.Using the Clohessy-Wiltshire equations as the relative motion dynamics model,a prescribed time output feedback control strategy is proposed.A prescribed-time extended state observer is designed to estimate the relative velocity and external disturbances.The disturbance estimates are then used as the feedforward component of the controller.Building on this framework,a novel prescribed-time active disturbance rejection control strategy for position tracking is developed via a backstepping control design.The convergence of the extended state observer and the stability of the closed-loop system are rigorously analyzed using Lyapunov stability theory.Numerical simulations are performed to validate the effectiveness of the proposed controller.展开更多
This paper reports the preparation of three di‑iron complexes containing a thiazole moiety.Esterification of complex[Fe_(2)(CO)_(6)(μ‑SCH_(2)CH(CH_(2)OH)S)](1)with 4‑methylthiazole‑5‑carboxylic acid gave the correspo...This paper reports the preparation of three di‑iron complexes containing a thiazole moiety.Esterification of complex[Fe_(2)(CO)_(6)(μ‑SCH_(2)CH(CH_(2)OH)S)](1)with 4‑methylthiazole‑5‑carboxylic acid gave the corresponding ester[Fe_(2)(CO)_(6)(μ‑tedt)](2),where tedt=SCH_(2)CH(CH_(2)OOC(5‑C_(3)HNSCH_(3)))S.Further reactions of complex 2 with tri(ptolyl)phosphine(tp)or tris(4‑fluorophenyl)phosphine(fp)gave the phosphine‑substituted derivatives[Fe_(2)(CO)_(5)(tp)(μ‑tedt)](3)and[Fe_(2)(CO)_(5)(fp)(μ‑tedt)](4).The structures of the newly prepared complexes were elucidated by elemental analysis,NMR,IR,and X‑ray photoelectron spectroscopy.Moreover,single‑crystal X‑ray diffraction analysis confirmed their molecular structures,showing that they contain a di‑iron core ligated by a bridged dithiolate bearing a thiazole moiety and terminal carbonyls.The electrochemical and electrocatalytic proton reduction were probed by cyclic voltammetry,revealing that three complexes can catalyze the reduction of protons to H_(2) under the electrochemical conditions.For comparison,complex 4 possessed the best efficiency with a turnover frequency of 23.5 s^(-1)at 10 mmol·L^(-1)HOAc concentration.In addition,the fungicidal activity of these complexes was also investigated in this study.CCDC:2477511,2;2477512,3;2477513,4.展开更多
In 2025,I had the honor of delivering keynote speeches at the conferences of the International Society for Diet and Activity Methods in Toronto,Canada,and the International Society of Behavioural Nutrition and Physica...In 2025,I had the honor of delivering keynote speeches at the conferences of the International Society for Diet and Activity Methods in Toronto,Canada,and the International Society of Behavioural Nutrition and Physical Activity in Auckland,Aotearoa,New Zealand.These opportunities prompted deep reflection on scientific research in general,and on physical activity and health research specifically.展开更多
Objective:To investigate the efficacy and mechanism of Ditan Qingnao decoction(DTQND)in alleviating schizophrenia-like symptoms in a maternal immune activation(MIA)-induced rat model.Methods:DTQND components were anal...Objective:To investigate the efficacy and mechanism of Ditan Qingnao decoction(DTQND)in alleviating schizophrenia-like symptoms in a maternal immune activation(MIA)-induced rat model.Methods:DTQND components were analyzed using high-performance liquid chromatography-tandem mass spectrometry.An MIA-induced rat model was established by injecting Poly Ⅰ:C into pregnant dams on gestational day 9.Male offspring were administered DTQND(14.1 g/kg),risperidone(RIS;0.4 mg/kg),or distilled water,while the controls received only distilled water via gavage for 4 weeks.Behavioral assessments were conducted using the open-field,Y-maze,prepulse inhibition,and sucrose preference tests.Serum levels of interleukin(IL)-6,IL-18,IL-1β,and tumor necrosis factor-α(TNF-α)were measured via an enzyme-linked immunosorbent assay.Hippocampal protein levels of nuclear factor kappa B p65(NF-κB p65),phospho-NF-κB p65(p-p65),inhibitor of kappa B-alpha(IκB-α),phospho-IκB-α(p-IκB-α),and nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing protein 3(NLRP3)were assessed via western blots.Immunohistochemistry detected hippocampal expression of ionized calcium-binding adapter molecule 1(Iba1)and cluster of differentiation 68(CD68).Results:Multiple DTQND compounds were identified,including stachyose,β-syringin,and isofraxidin,among others.DTQND treatment considerably enhanced spontaneous activity,reduced anxiety,improved spatial working memory,and alleviated sensory gating defects in male offspring with MIA.The DTQND group showed significantly lower serum levels of IL-1β(P=.002)and IL-18(P=.046)than the model group,with no discernible variations in IL-6 or TNF-α levels.In the hippocampus,DTQND significantly suppressed the expression of p-p65(P<.001),p-IκB-α(P=.023),and NLRP3(P<.001)compared to the model group.Additionally,DTQND modulated microglial activation markers,decreasing CD68 expression(P=.004)without affecting Iba1 levels.Conclusions:DTQND alleviated schizophrenia-like behavioral deficits and cognitive impairment by inhibiting the NF-κB/NLRP3 pathway,supporting its potential as an alternative therapy for schizophrenia.展开更多
Biomass-derived carbon materials are favored for their abundance and sustainability,and ease of preparation and modification.By surface activation and modification they can have a good electrical conductivity,excellen...Biomass-derived carbon materials are favored for their abundance and sustainability,and ease of preparation and modification.By surface activation and modification they can have a good electrical conductivity,excellent catalytic activity,a remarkable adsorption capacity,and different interfacial physicochemical functionalities.Surface-modified biochars have found wide applications in energy storage,environmental remediation,and catalysis.However,achieving precise and controllable modification of their active sites remains a challenge.Recent advances and future prospects for controlling their surface morphology,defect engineering,and surface coating strategies,with particular attention to their means of fabrication,are reviewed.展开更多
Chitosan(CTS)was grafted onto the surface of amino‑functionalized silver chloride silicon dioxide(AgCl@SiO_(2)‑NH_(2))cores to obtain AgCl@SiO_(2)/CTS hybrid nanoparticles.The as‑obtained AgCl@SiO_(2)/CTS nanoparticle...Chitosan(CTS)was grafted onto the surface of amino‑functionalized silver chloride silicon dioxide(AgCl@SiO_(2)‑NH_(2))cores to obtain AgCl@SiO_(2)/CTS hybrid nanoparticles.The as‑obtained AgCl@SiO_(2)/CTS nanoparticles were chlorinated by NaClO solution to get AgCl@SiO_(2)/CTS‑based chloramine nano‑hybrid materials,denoted as AgCl@SiO_(2)/CTS‑Cl.A transmission electron microscope was used to observe the morphology of the as‑prepared samples AgCl@SiO_(2)/CTS and AgCl@SiO_(2)/CTS‑Cl.At the same time,an X‑ray diffractometer and an infrared spectroscope were utilized to characterize their crystal and chemical structures.Besides,ζpotentials were measured to elucidate the surface modification of AgCl nanoparticles by—NH_(2),the antibacterial mechanism of AgCl@SiO_(2)/CTS‑Cl was investigated by scanning electron microscopy,and Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)were used as the to‑be‑tested strains to evaluate the antimicrobial activity of samples AgCl@SiO_(2)/CTS and AgCl@SiO_(2)/CTS‑Cl.Findings demonstrate that sample AgCl@SiO_(2)/CTS exhibits a chain‑like structure ascribed to the interaction between—NH_(2),and each AgCl@SiO_(2)/CTS hybrid nanoparticle contains several AgCl cores.In the meantime,sample AgCl@SiO_(2)/CTS‑Cl exhibits excellent antibacterial activity against E.coli and S.aureus,which is attributed to the synergistic antibacterial effect of Ag^(+)and Cl^(-).Sample AgCl@SiO_(2)/CTS‑Cl with a dosage of 640.00μg·mL^(-1) could completely kill the two kinds of tested bacteria in 12 h of incubation;it retains a high antibacterial efficiency even after 10 cycles of antibacterial tests.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.52475574).
文摘Harmonic mode-locking(HML)in soliton fiber lasers is crucial for generating high-repetition-rate pulse trains beyond the fundamental cavity frequency,enabling advanced applications in,for example,optical communication and precision sensing.However,achieving HML in experiments is challenging,owing to its inherent instability and high sensitivity to laser parameters,resulting in complex and iterative adjustments.In this paper,a novel HML technique utilizing bidirectional adjustment of pump power is proposed,and it is experimentally demonstrated in an all-fiber hybrid mode-locked soliton laser.By first increasing the pump power to generate a soliton bunch with a certain number of pulses and then gradually decreasing it,HML can be achieved at an order corresponding to the number of pulses in the soliton bunch.Experimental results on the evolution of temporal pulse trains during bidirectional adjustment of the pump power enable a relationship to be established between pump power and soliton bunching with increasing pump power,and reveal the collapse of the soliton bunch and subsequent gradual uniform distribution of solitons into an HML state with decreasing pump power.Second-to sixth-order HML is successfully generated using the proposed technique,and an analysis of the results provides a deeper understanding of the observed pulse dynamics.
基金Project supported by the National Natural Science Foundation of China(Grant No.12204132)the Natural Science Foundation of Shandong Province,China(Grant No.ZR2021MF122)+1 种基金Shandong Province TechnologyBased SME Innovation Enhancement Project(Grant No.2024TSGC0715)the Postgraduate Education Reform Project of Shandong Province,China(Grant No.SDYJSJGC2024107)。
文摘We achieved an ultra-flat broad spectrum output with a 20-dB bandwidth of 77.85 nm in a double-clad Yb-doped fiber laser.The intensity difference between the highest and lowest points of the spectrum indicates a flatness better than4 dB.More notably,this ultra-flat broad spectrum maintains a stable single-pulse mode-locking state.With the increase of pump power,an ultra-wide spectrum with a 20-dB bandwidth approaching 100 nm was formed at a pump power of 2.25 W.Additionally,we obtained a 9-pulse mode-locked state at another PC station with the same pump,which is the highest number of stable mode-locked pulse bursts observed so far with a first-order Raman frequency shift.This fiber laser shows its benefits of ultra-flat broad spectrum,high stability,and ease of fabrication,which provides a new method of obtaining the broadband light source for multiple practical applications.
基金Supported by the National Natural Science Foundation of China under Grant Nos 61308009 and 61405047the China Postdoctoral Science Foundation Funded Project under Grant Nos 2013M540288 and 2015M570290+2 种基金the Fundamental Research Funds for the Central Universities Grant under Grant Nos HIT.NSRIF.2014044 and HIT.NSRIF.2015042the Science Fund for Outstanding Youths of Heilongjiang Province under Grant No JQ201310the Heilongjiang Postdoctoral Science Foundation Funded Project under Grant No LBH-Z14085
文摘An actively mode-locked Ho： YAG laser pumped by a diode-pumped Tin-doped fiber laser is reported. For the cw operation, we obtain the maximum output power of 3.43 W with a central wavelength 2022.2nm at the maximum incident pump power of 11.4 W, corresponding to a slope efficiency of 34.5%. The beam quality factor M2 is 1.16, and the output beam is close to fundamental TEMoo. In the case of the CWML operation, a stable pulse train is generated with an average output power up to 3.41 W with a slope efficiency of 34.3% at the incident pump power of 11.4 W and a pulse duration of 294ps at a repetition rate of 81.92MHz. In addition, the maximum single pulse energy is 41.6nJ.
基金Project supported by the National Natural Science Foundation of China(Grant No.12164030)Young Science and Technology Talents of Inner Mongolia,China(Grant No.NJYT22101)+1 种基金the Central Government Guides Local Science,the Technology Development Fund Projects(Grant No.2023ZY0005)the Science and Technology Plan Projects of Inner Mongolia Autonomous Region of China(Grant No.2023KYPT0012)。
文摘In the last few years,research on advanced ultrafast photonic devices has attracted great interest from laser physicists.As a semiconductor material with excellent nonlinear saturation absorption characteristics,Ga As has been used in solidstate and fiber lasers as a mode-locker.However,the pulse widths that have been reported in the searchable published literature are all long and the shortest is tens of picoseconds.Femtosecond pulse widths,desired for a variety of applications,have not yet been reported in Ga As-based pulsed lasers.In this work,we further explore the nonlinear characteristics of Ga As that has been magnetron sputtered onto the surface of a tapered fiber and its application in the generation of femtosecond lasing via effective dispersion optimization and nonlinearity management.With the enhanced interaction between evanescent waves and Ga As nanosheets,mode-locked soliton pulses as short as 830 fs are generated at repetition rates of 4.64 MHz.As far as we know,this is the first time that femtosecond-level pulses have been generated with a Ga As-based saturable absorber.In addition,soliton molecules,including in the dual-pulse state,are also realized under stronger pumping.This work demonstrates that Ga As-based photonic devices have good application prospects in effective polymorphous ultrashort pulsed laser generation.
文摘We designed and investigated a passive synchronized mode-locked fiber laser.The device utilizes a dual-cavity structure driven by the nonlinear polarization rotation(NPR)mechanism.Stable mode-locking is attained by synergistically controlling gain,polarization state,and optical path length in two symmetric sub-cavities.Experiments proved that repetition rate of the sub-cavities can be adjusted via the time delay line(TDL)to achieve synchronized mode-locking.The system stably generates multi-wavelength pulses at a single repetition frequency,evidenced by multiple spectral peaks and equidistant pulse sequences.These findings facilitate the development of high-performance multi-wavelength ultrashort pulse sources,crucial for optical communications,spectral analysis,and remote sensing.
基金Project supported by the National Natural Science Foundation of China(No.32160108)the Science and Technology Special Fund of Hainan Province(No.ZDYF2024SHFZ116)+2 种基金the Specific Research Fund of the Innovation Center for Academicians of Hainan Province(No.YSPTZX202309)the Scientific Research Project of Hainan Higher Education Institutions(No.Hnky2022ZD-6)the Hainan Normal University National College Student Innovation Training Program(No.202411658006)。
文摘new heterocyclic dipeptide with a highly functionalized 1,2-oxazadecaline core,named trichodermamide H(1),and three known analogues,along with three known polyketides,were isolated from the fermentation extract of the mangrovederived fungus Penicillium janthinellum XLN32122.The structure of 1 was elucidated on the basis of extensive 1D and 2D NMR spectra data analysis,HR-ESI-MS,electronic circular dichroism(ECD)calculations.Trichodermamide B(3)exhibited better inhibitory effect on nitric oxide(NO)production in lipopolysaccharide(LPS)induced RAW 264.7 cells with an IC_(50)value of(13.13±0.005)μmol/L than that of the positive control dexamethasone[IC_(50)=(136.84±1.33)μmol/L].Compound 3 exhibited antibacterial activity against methicillin-resistant Staphylococcus aureus(MRSA)with an IC_(50)value of 12.5μg/mL,while the positive control vancomycin showed an IC_(50)value of 1.563μg/mL.
文摘Lithium–sulfur(Li–S)batteries are promisingcandidates for next-generation energy storagegiven their high energy density and potential low cost.Chemically activated carbon(CAC)is often used fortheir cathodes,because it has a high specific surfacearea for sulfur loading.We have developed a pressurizedphysical activation(PPA)method that producedan activated carbon(PPAC)with a high specific surfacearea comparable to that of CAC.The pore structure of PPAC could be changed and its use as a cathode material for Li–Sbatteries was investigated.Battery tests at different capacity rates(C-rates)showed that it had a much improved high-rate performancewith a discharge capacity of 900 mAh/(g of sulfur)at 1 C,in contrast to only 600 mAh/(g of sulfur)for CAC.Porestructure analyses showed that PPAC prepared at a high activation temperature(1000℃)had unusual channel-like mesoporesbetween the microdomains that are the basic structural units of artificial carbon materials.These are connected to microporesdeveloped in each microdomain,and deliver ions from the surroundings to the internal pores and vice versa.The well-developedmicropores and mesopores of PPAC respectively ensured the high adsorption of lithium polysulfides and a high rate ofion diffusion.Compared to CAC,PPAC is a high-performance,low-cost cathode material that is promising for use in futureLi–S batteries.
基金Supported by National Natural Science Foundation of China (No. 69877012).
文摘The supercontinuum (SC) generation at the repetition rate of 10 GHz is presented. The SC is generated in a 4.2 km conventional dispersion-shifted fiber ( DSF), which is produced with nonlinear effects and group velocity dispersion. The DSF is pumped by an actively mode-locked Er3+ -doped fiber laser with pulse width of 7.97 ps. A novel SC pulse source with a bandwidth up to 125 nm is obtained, which covers the whole C, L bands and part of S band. The stable, narrow pulses with mean pulse-width of 9.7 ps and time-bandwidth product of 0.48 are filtered out across the whole SC bandwidth. This supercontinuum pulse source is suitable for future high-speed optical communications.
基金Project supported by the National Key Research and Development Program of China(Grant No.2017YFF0106302)the National Natural Science Foundation of China(Grant Nos.61975225 and 61927813)Shanghai International Cooperation Project,China(Grant No.18590780100).
文摘The pulse generation from active mode-locking terahertz quantum cascade laser is studied by Maxwell-Bloch equations.It is shown that longer dephasing time will lead to multiple pulses generation from the laser.The dependence of output field on modulation length and radio-frequency parameters is obtained.In order to achieve short pulse generation,the DC bias should close to threshold value and modulation length should be shorter than 0.256 mm.The output pulse is unstable and the envelope shows many oscillations in the presence of spatial hole burning,resulting destabilization of mode-locking.
文摘A modified multiwavelength actively mode-locked fiber ring laser is proposed and experimentally demonstrated. In this kind of laser, stable multiwavelengths lasing is achieved by integrating cascaded sampled fiber Bragg gratings(SFBGs) into the laser cavity. To implement actively mode-locking technique, a double-ring cavity configuration is used to assure that the cavity lengths for all wavelengths lasing are identical. Thus, simultaneous mode locking of all wavelengths has been successfully achieved by using the same mode-locking signal.
文摘Two new linear furocoumarins were isolated from Notopterygium incisum using silica gel,gel Sephadex LH-20 column chromatography,and preparative high-performance liquid chromatography.The structures of the new compounds were elucidated through analysis of spectroscopic evidence,including data obtained from high-resolution electrospray ionization mass spectrometry(HRESIMS)and nuclear magnetic resonance(NMR).The absolute configurations of Notoprenylate L(1)and Nototerprinol K(2)were further confirmed using electronic circular dichroism(ECD)calculations.Compound 1 demonstrated the ability to inhibit the expression of nitric oxide(NO),a pro-inflammatory factor,in lipopolysaccharide-induced RAW264.7 macrophages at a concentration of 7.5μmol/L,indicating its potential for anti-inflammatory activity.
文摘Two Co(Ⅱ)and Ni(Ⅱ)complexes were synthesized by synergistic coordination of 3,3-diphenylpropionic acid(HDPA)and 2,2′-bipyridylamine(PAm).The structures of complexes[Co(DPA)_(2)(PAm)]·2H_(2)O(1)and[Ni(DPA)_(2)(PAm)]·2H_(2)O(2)were determined by single-crystal X-ray diffraction,IR spectroscopy,and powder X-ray diffraction.Hirshfeld surface analysis provided quantitative insights into the intermolecular interactions within the complexes,while molecular docking studies elucidated their binding modes and affinities toward urease.Furthermore,the biological activities of both complexes were systematically evaluated through a range of assays,including DNA binding,urease inhibition,antibacterial activity,and in vitro cytotoxicity against cancer cells.Both complexes exhibited binding affinity for DNA and displayed notable urease inhibitory activity.Under in vitro conditions,both complexes showed appreciable cytotoxicity toward HepG2 cells with efficacy comparable to clinically used platinumbased anticancer agents.CCDC:2479943,1;2479944,2.
文摘Passiflora incarnata L.,commonly known as passionflower,is traditionally cultivated as an ornamental plant but has demonstrated diverse therapeutic potential.Its pharmacological effects are attributed to bioactive compounds such as flavonoids and alkaloids,which influence multiple biological pathways.This review aims to summarise and critically analyse recent findings on the pharmacological properties of Passiflora incarnata L.,focusing on its neuropsychiatric,antioxidant,antimicrobial,and anticancer activities.A targeted literature search was conducted in PubMed,Scopus,Web of Science,and Google Scholar for peer-reviewed publications between 2000 to 2025.Relevant articles were screened,and a more appropriate article related to the objective of the review was selected.Some classical papers are also cited as per the requirement of the topic.Passiflora incarnata L.showed multifunctional medicinal properties with various applications in neuropsychiatry,oxidative stress management,antimicrobial agent,and as an anticancer agent.The U.S.Food and Drug Administration categorizes passionflower extracts as“generally recognized as safe”.However,most evidence remains preclinical,with methodological variation limiting generalisation.Standardised formulation,robust clinical trials,and in-depth in vivo studies are essential to establish its therapeutic relevance and safety in modern medicine.
文摘To address the longstanding challenge in traditional carborane methodology of rapidly and efficiently constructing carboranyl-based polycyclic frameworks,Pd-catalyzed one-pot reactions between pyridyl-substituted nidocarboranes and alkynes directly afford two distinct types of 2D-3D fused carboranyl polycyclic compounds:3a-3f,4a-4d.The structures of this series of compounds were characterized by nuclear magnetic resonance spectroscopy,single-crystal X-ray diffraction,and high-resolution mass spectrometry,and a plausible reaction mechanism was proposed.Crystal structures reveal that the multiple rings in such 2D-3D fused carboranyl polycyclic compounds exhibit a certain degree of coplanarity.Furthermore,these compounds exhibited properties distinct from those of conventional 2D polycyclic systems.CCDC:2481988,3c,2481990,3f,2481986,4d.
文摘This study investigates prescribed-time position tracking control for electromagnetic satellite formations subject to model uncertainties and external disturbances.Using the Clohessy-Wiltshire equations as the relative motion dynamics model,a prescribed time output feedback control strategy is proposed.A prescribed-time extended state observer is designed to estimate the relative velocity and external disturbances.The disturbance estimates are then used as the feedforward component of the controller.Building on this framework,a novel prescribed-time active disturbance rejection control strategy for position tracking is developed via a backstepping control design.The convergence of the extended state observer and the stability of the closed-loop system are rigorously analyzed using Lyapunov stability theory.Numerical simulations are performed to validate the effectiveness of the proposed controller.
文摘This paper reports the preparation of three di‑iron complexes containing a thiazole moiety.Esterification of complex[Fe_(2)(CO)_(6)(μ‑SCH_(2)CH(CH_(2)OH)S)](1)with 4‑methylthiazole‑5‑carboxylic acid gave the corresponding ester[Fe_(2)(CO)_(6)(μ‑tedt)](2),where tedt=SCH_(2)CH(CH_(2)OOC(5‑C_(3)HNSCH_(3)))S.Further reactions of complex 2 with tri(ptolyl)phosphine(tp)or tris(4‑fluorophenyl)phosphine(fp)gave the phosphine‑substituted derivatives[Fe_(2)(CO)_(5)(tp)(μ‑tedt)](3)and[Fe_(2)(CO)_(5)(fp)(μ‑tedt)](4).The structures of the newly prepared complexes were elucidated by elemental analysis,NMR,IR,and X‑ray photoelectron spectroscopy.Moreover,single‑crystal X‑ray diffraction analysis confirmed their molecular structures,showing that they contain a di‑iron core ligated by a bridged dithiolate bearing a thiazole moiety and terminal carbonyls.The electrochemical and electrocatalytic proton reduction were probed by cyclic voltammetry,revealing that three complexes can catalyze the reduction of protons to H_(2) under the electrochemical conditions.For comparison,complex 4 possessed the best efficiency with a turnover frequency of 23.5 s^(-1)at 10 mmol·L^(-1)HOAc concentration.In addition,the fungicidal activity of these complexes was also investigated in this study.CCDC:2477511,2;2477512,3;2477513,4.
文摘In 2025,I had the honor of delivering keynote speeches at the conferences of the International Society for Diet and Activity Methods in Toronto,Canada,and the International Society of Behavioural Nutrition and Physical Activity in Auckland,Aotearoa,New Zealand.These opportunities prompted deep reflection on scientific research in general,and on physical activity and health research specifically.
基金supported by the Beijing Natural Science Foundation(7222274)the Fifth Batch of National Outstanding Talents in Clinical Chinese Medicine(20221)。
文摘Objective:To investigate the efficacy and mechanism of Ditan Qingnao decoction(DTQND)in alleviating schizophrenia-like symptoms in a maternal immune activation(MIA)-induced rat model.Methods:DTQND components were analyzed using high-performance liquid chromatography-tandem mass spectrometry.An MIA-induced rat model was established by injecting Poly Ⅰ:C into pregnant dams on gestational day 9.Male offspring were administered DTQND(14.1 g/kg),risperidone(RIS;0.4 mg/kg),or distilled water,while the controls received only distilled water via gavage for 4 weeks.Behavioral assessments were conducted using the open-field,Y-maze,prepulse inhibition,and sucrose preference tests.Serum levels of interleukin(IL)-6,IL-18,IL-1β,and tumor necrosis factor-α(TNF-α)were measured via an enzyme-linked immunosorbent assay.Hippocampal protein levels of nuclear factor kappa B p65(NF-κB p65),phospho-NF-κB p65(p-p65),inhibitor of kappa B-alpha(IκB-α),phospho-IκB-α(p-IκB-α),and nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing protein 3(NLRP3)were assessed via western blots.Immunohistochemistry detected hippocampal expression of ionized calcium-binding adapter molecule 1(Iba1)and cluster of differentiation 68(CD68).Results:Multiple DTQND compounds were identified,including stachyose,β-syringin,and isofraxidin,among others.DTQND treatment considerably enhanced spontaneous activity,reduced anxiety,improved spatial working memory,and alleviated sensory gating defects in male offspring with MIA.The DTQND group showed significantly lower serum levels of IL-1β(P=.002)and IL-18(P=.046)than the model group,with no discernible variations in IL-6 or TNF-α levels.In the hippocampus,DTQND significantly suppressed the expression of p-p65(P<.001),p-IκB-α(P=.023),and NLRP3(P<.001)compared to the model group.Additionally,DTQND modulated microglial activation markers,decreasing CD68 expression(P=.004)without affecting Iba1 levels.Conclusions:DTQND alleviated schizophrenia-like behavioral deficits and cognitive impairment by inhibiting the NF-κB/NLRP3 pathway,supporting its potential as an alternative therapy for schizophrenia.
文摘Biomass-derived carbon materials are favored for their abundance and sustainability,and ease of preparation and modification.By surface activation and modification they can have a good electrical conductivity,excellent catalytic activity,a remarkable adsorption capacity,and different interfacial physicochemical functionalities.Surface-modified biochars have found wide applications in energy storage,environmental remediation,and catalysis.However,achieving precise and controllable modification of their active sites remains a challenge.Recent advances and future prospects for controlling their surface morphology,defect engineering,and surface coating strategies,with particular attention to their means of fabrication,are reviewed.
文摘Chitosan(CTS)was grafted onto the surface of amino‑functionalized silver chloride silicon dioxide(AgCl@SiO_(2)‑NH_(2))cores to obtain AgCl@SiO_(2)/CTS hybrid nanoparticles.The as‑obtained AgCl@SiO_(2)/CTS nanoparticles were chlorinated by NaClO solution to get AgCl@SiO_(2)/CTS‑based chloramine nano‑hybrid materials,denoted as AgCl@SiO_(2)/CTS‑Cl.A transmission electron microscope was used to observe the morphology of the as‑prepared samples AgCl@SiO_(2)/CTS and AgCl@SiO_(2)/CTS‑Cl.At the same time,an X‑ray diffractometer and an infrared spectroscope were utilized to characterize their crystal and chemical structures.Besides,ζpotentials were measured to elucidate the surface modification of AgCl nanoparticles by—NH_(2),the antibacterial mechanism of AgCl@SiO_(2)/CTS‑Cl was investigated by scanning electron microscopy,and Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)were used as the to‑be‑tested strains to evaluate the antimicrobial activity of samples AgCl@SiO_(2)/CTS and AgCl@SiO_(2)/CTS‑Cl.Findings demonstrate that sample AgCl@SiO_(2)/CTS exhibits a chain‑like structure ascribed to the interaction between—NH_(2),and each AgCl@SiO_(2)/CTS hybrid nanoparticle contains several AgCl cores.In the meantime,sample AgCl@SiO_(2)/CTS‑Cl exhibits excellent antibacterial activity against E.coli and S.aureus,which is attributed to the synergistic antibacterial effect of Ag^(+)and Cl^(-).Sample AgCl@SiO_(2)/CTS‑Cl with a dosage of 640.00μg·mL^(-1) could completely kill the two kinds of tested bacteria in 12 h of incubation;it retains a high antibacterial efficiency even after 10 cycles of antibacterial tests.
