In this paper,a hybrid electronic noses’system(HENS)based on MOS-SAW detection units intended for lung cancer diagnosis is proposed.The MOS gas sensors are used to detect the VOC molecules with low molecular weight(L...In this paper,a hybrid electronic noses’system(HENS)based on MOS-SAW detection units intended for lung cancer diagnosis is proposed.The MOS gas sensors are used to detect the VOC molecules with low molecular weight(LMW),and the SAW sensors are adopted for the detection of VOC with high molecular weight(HMW).Thus,the novel combination of these two kinds of gas sensors provides higher sensitivities to more of VOC species in breath than that of using only a single kind of sensor.The signals from MOS-SAW detection units are then recognized by a multi-model diagnosis method.Applying four algorithms,six models were established for diagnosis and tested by leave-one-out cross-validation method.The model by artificial neural network(ANN)was selected as the best model to analyze breath samples.89 clinical samples were tested with MOS-SAW ANN diagnostic model,which takes the features derived from both the MOS and SAW sensors.It shows the highest sensitivity of 93.62%,and the highest selectivity of 83.37%.The study shows that,promisingly,our HENS is effective during screening of lung cancer patients,especially among the people of high risk.展开更多
Purpose: To explore the effect of rhIL-12 on the number of the blood cells and CD4/8+ T, CD45+ leukocytes, and CD56+ NK cells in liver cancer patients following radiation therapy. Methods: We selected forty liver canc...Purpose: To explore the effect of rhIL-12 on the number of the blood cells and CD4/8+ T, CD45+ leukocytes, and CD56+ NK cells in liver cancer patients following radiation therapy. Methods: We selected forty liver cancer patients who carried out by cyber knife (the patients were given 5 Gy every time for 5 times continuously) to observe the size of the tumor. After thirty hours, rhIL-12 was injected into the liver cancer patients via subcutaneous at the concentration of 50 ng/kg, 100 ng/kg, 200 ng/kg and 300 ng/kg in different patients, respectively. And there were ten patients in the four groups, respectively. The twenty patients who were selected from the hospital without rhIL-12 treatment were used as controls. All the blood cells were collected from different groups on day 0, hour 12, day 7, day 14, day 21 and day 28 after rhIL-12 treatment, respectively. The full number of blood cells in every group was analyzed by ELISA. The number of CD4/8+ T, CD45+ leukocytes, and CD56+ NK cells were detected by Flow Cytometry. After one month with rhIL-12 treatment, ECOG and WHO were used to evaluate the prognosis of liver cancer. Results: In present study, we found that the number of blood cells was significantly decreased on day 0 - day 3, while recovered from day 7 - day 14 and down-regulated on day 21 after rhIL-12 treatment. The number of CD4/8+ T, CD45+ leukocytes, and CD56+ NK cells was elevated with any concentration of rhIL-12. Furthermore, results showed that number of white blood cells was obviously higher than in patients without rhIL-12 treatment (P < 0.05). However, there was no significant difference of erythrocyte and platelet, between groups treated with rhIL-12 and control groups. In addition, the immune cells including CD4/8+ T, CD45+ leukocytes, and CD56+ NK cells were reduced on day 0 - day 3, recovered from day 7, and then decreased from day 21 in rhIL-12 treatment groups related to control groups (P < 0.05). Furthermore, studies showed that five patients developed symptoms of fever, bilirubin increased and liver dysfunction with the dose of 300 ng/kg. So we found that the safe and well-tolerated human dose of 200 ng/kg is within this efficacious range based on exposure parameters through the research. Higher ECOG and WHO scores were observed in rhIL-12 treatment groups compared to control groups (P = 0.025, P = 0.044, respectively). Conclusion: Our results suggested that rhIL-12 could recover the liver cancer induced aberrant blood cell number and CD4/8+ T, CD45+ leukocytes, and CD56+ NK cells , which may be an effective method to alleviate the progress of liver cancer and played an important role in treating liver cancer.展开更多
With the further requirements of electronic products and powered vehicles,the development of a new generation with low-voltage and high-capacity anode materials is crucial for lithium-ion batteries(LIBs).Transition me...With the further requirements of electronic products and powered vehicles,the development of a new generation with low-voltage and high-capacity anode materials is crucial for lithium-ion batteries(LIBs).Transition metal phosphides,especially cobalt phosphide(CoP)composites,have become a research hotspot for LIBs anode materials in recent years due to their high theoretical specific capacity,low polarization,and suitable voltage plateau.This review first systematically discusses the lithium storage mechanism and preparation methods of CoP in current research.Subsequently,the applications of CoP anode materials in LIBs are categorically reviewed,including the composites of CoP with various types of carbon materials and heterostructures.Finally,the challenges and future development directions of CoP anode materials are summarized to provide guidance for further improving the lithium storage performance of CoP and its practical applications.展开更多
This review presents a summary of the research conducted thus far on the recovery of various types of valuable metals from red mud. The composition, properties, environmental hazards, and current status of comprehensi...This review presents a summary of the research conducted thus far on the recovery of various types of valuable metals from red mud. The composition, properties, environmental hazards, and current status of comprehensive utilization of red mud were studied. A number of studies have been conducted on the use of red mud as a modifying additive for cement, the development of various catalysts based on red mud, and the recovery of various valuable metals from red mud. Furthermore, we examine several techniques for extracting various types of valuable metals from red mud, including pyrometallurgical recovery, wet leaching recovery, and emerging biobased technology recovery. We investigate the underlying principles, processes, research progress, and the potential for industrial application of these methods, and assess the advantages and disadvantages of each from the perspectives of economic and environmental benefits. Although these methods have certain disadvantages, in general, the recovery of various types of valuable metals from red mud is an effective way to solve the problem of red mud and the supply of metal raw materials. In conclusion, this paper presents an overview of the current state of red mud development and utilization, as well as the various methods employed for the recovery of valuable metals from red mud.展开更多
In recent years,significant progress has been achieved in the creation of innovative functional materials for energy storage and conversion.Due to their distinct physicochemical characteristics,ultrathin nanosheets co...In recent years,significant progress has been achieved in the creation of innovative functional materials for energy storage and conversion.Due to their distinct physicochemical characteristics,ultrathin nanosheets composed of common layered transition metal sulfide materials(MoS2)have demonstrated promise as high-capacity anode materials for lithium-ion batteries(LIBs).Nevertheless,their practical application is severely limited by the tendency of monolayer nanosheets to restack due to strong van der Waals forces,dramatic volume changes during successive cycles,and low intrinsic conductivity.Recent research advances have shown that composite structures and nanowire morphologies with specific morphologies effectively overcome these issues.This paper reviews the recent research progress on molybdenum disulfide-based composites as anode materials for LIBs and discusses in detail the struc-tural characteristics of pure molybdenum disulfide and other composite forms of molybdenum disulfide.In addition,the phase engineering,defect engineering,and lithium storage mechanisms of molybdenum disulfide and the synthesis of molybdenum disulfide-based nanocomposites by different preparation methods are focused on.Finally,we review the design(structure),recent developments,and challenges of novel anode materials and consider their electrochemical performance in Li-ion batteries.展开更多
Manganese dioxide(MnO2)is a widely used and well-studied 3-dimensional(3D)transition metal oxide,which has advantages in ultrafast optics due to large specific surface area,narrow bandgap,multiple pores,superior elect...Manganese dioxide(MnO2)is a widely used and well-studied 3-dimensional(3D)transition metal oxide,which has advantages in ultrafast optics due to large specific surface area,narrow bandgap,multiple pores,superior electron transfer capability,and a wide range of light absorption.However,few studies have considered its excellent performance in ultrafast photonics.y-MnO2 photonics devices were fabricated based on a special dual-core,pair-hole fiber(DCPHF)carrier and applied in ultrafast optics fields for the first time.The results show that the soliton molecule with tunable temporal separation(1.84 to 2.7 ps)and 600-MHz harmonic solitons are achieved in the experiment.The result proves that this kind of photonics device has goodapplications in ultrafast lasers,high-performance sensors,fiber optical communications,etc.,which can help expand the prospect of combining 3D materials with novel fiber for ultrafast optics device technology.展开更多
Ultrashort pulsed Bessel beams with intrinsic nondiffractive character and potential strong excitation confinement down to 100nm can show a series of advantages over Gaussian beams in fabricating efficient Bragg grati...Ultrashort pulsed Bessel beams with intrinsic nondiffractive character and potential strong excitation confinement down to 100nm can show a series of advantages over Gaussian beams in fabricating efficient Bragg grating waveguides(BGWs).In this work, we focus on parameter management for the inscription of efficient BGWs using the point-by-point method employing Bessel beams.Due to their high aspect ratio, the resulting one-dimensional void-like structures can section the waveguides and interact efficiently with the optical modes. Effective first-order BGWs with low birefringence can then be fabricated in bulk fused silica. By controlling the size and the relative location of grating voids via the Bessel pulse energy and scan velocities, the resonant behaviors of BGWs can be well regulated.A high value of 34 dB for 8 mm length is achieved.A simple predictive model for BGWs is proposed for analyzing the influences of processing parameters on the performance of BGWs. The technique permits multiplexing several gratings in the same waveguide.Up to eight grating traces were straightforwarcliy inscribed into the waveguide in a parallel-serial combined mode, forming the multiplex BGWs.As an application, the multiplex BGW sensor with two resonant peaks is proposed and fabricated for improving the reliability of temperature detection.展开更多
Dual-pumped microring-resonator-based optical frequency combs(OFCs) and their temporal characteristics are numerically investigated and experimentally explored. The calculation results obtained by solving the driven a...Dual-pumped microring-resonator-based optical frequency combs(OFCs) and their temporal characteristics are numerically investigated and experimentally explored. The calculation results obtained by solving the driven and damped nonlinear Schr?dinger equation indicate that an ultralow coupled pump power is required to excite the primary comb modes through a non-degenerate four-wave-mixing(FWM) process and, when the pump power is boosted, both the comb mode intensities and spectral bandwidths increase. At low pump powers, the field intensity profile exhibits a cosine variation manner with frequency equal to the separation of the two pumps, while a roll Turing pattern is formed resulting from the increased comb mode intensities and spectral bandwidths at high pump powers. Meanwhile, we found that the power difference between the two pump fields can be transferred to the newly generated comb modes, which are located on both sides of the pump modes, through a cascaded FWM process. Experimentally, the dual-pumped OFCs were realized by coupling two self-oscillating pump fields into a microring resonator. The numerically calculated comb spectrum is verified by generating an OFC with 2.0 THz mode spacing over 160 nm bandwidth. In addition, the formation of a roll Turing pattern at high pump powers is inferred from the measured autocorrelation trace of a 10 free spectral range(FSR) OFC. The experimental observations accord well with the numerical predictions. Due to their large and tunable mode spacing, robustness,and flexibility, the proposed dual-pumped OFCs could find potential applications in a wide range of fields,including arbitrary optical waveform generation, high-capacity optical communications, and signal-processing systems.展开更多
Tricobalt tetroxide(Co_(3)O_(4))is one of the promising anodes for lithium-ion batteries(LIBs)due to its high theoretical capacity.However,the poor electrical conductivity and the rapid capacity decay hamper its pract...Tricobalt tetroxide(Co_(3)O_(4))is one of the promising anodes for lithium-ion batteries(LIBs)due to its high theoretical capacity.However,the poor electrical conductivity and the rapid capacity decay hamper its practical application.In this work,we design and fabricate a hierarchical Co_(3)O_(4)nanorods/N-doped graphene(Co_(3)0_(4)/NG)material by a facile hydrothermal method.The nitrogen-doped graphene layers could buffer the volume change of Co_(3)0_(4)nanorods during the delithium/lithium process,increase the electrical conductivity,and profit the diffusion of ions.As an anode,the Co_(3)O_(4)/NG material reveals high specific capacities of 1873.8 mA h g^(-1)after 120 cycles at 0.1 A·g^(-1)as well as 1299.5 mA·h·g^(-1)after 400 cycles at 0.5 A·g^(-1).Such superior electrochemical performances indicate that this work may provide an effective method for the design and synthesis of other metal oxide/N-doped graphene electrode materials.展开更多
In this paper,we innovatively conduct a Porro prism-based beam pointing stability promotion technique research and realize a high-performance rod-type photonic crystal fiber-based chirped pulse amplification(CPA)syste...In this paper,we innovatively conduct a Porro prism-based beam pointing stability promotion technique research and realize a high-performance rod-type photonic crystal fiber-based chirped pulse amplification(CPA)system,mainly including a frequency-reduced all-fiber pre-amplification stage,photonic crystal rod-based main amplification stage,and 1600 lines/mm transmission grating-pair compressor.Laser output with average power of 50 W,repetition rates of500 kHz,pulse energy of 100μJ,pulse duration of 830 fs,beam quality of M2<1.3,power fluctuation of 0.55%root mean square,and beam pointing drift of 19μrad/?C over 8 h is realized.The high-performance laser system has an enormous application potential in fundamental research and precision manufacturing fields.展开更多
Graphene oxide carboxylic acid(COOH), a novel two-dimensional(2D) layered material with its unique optical and electronic properties, is discovered to exhibit the saturation of optical absorption under laser illum...Graphene oxide carboxylic acid(COOH), a novel two-dimensional(2D) layered material with its unique optical and electronic properties, is discovered to exhibit the saturation of optical absorption under laser illumination.Applying the liquid-phase exfoliation method, we prepare graphene oxide-COOH dispersions with deionized water and fabricate graphene oxide-COOH polyvinyl alcohol polymer composite film. We further obtain stable Q-switching pulse and mode-locked laser operation with a 22.7 MHz repetition rate and a 1.5 ps pulse duration by incorporating the graphene oxide-COOH-based saturable absorbers into the all-fiber erbium-doped fiber laser cavity. The experimental results show that the proposed graphene oxide-COOH material can act as an effective absorber for pulsed fiber lasers, which demonstrate potential applications in the area of ultrafast optics.展开更多
The multi-peak spectrum of Ti: sapphire pulses observed experimentally under ultra-broad bandwidth conditions ( 【 15 fs pulse length) has been explained theoretically. It is shown that the self-phase-modulation effec...The multi-peak spectrum of Ti: sapphire pulses observed experimentally under ultra-broad bandwidth conditions ( 【 15 fs pulse length) has been explained theoretically. It is shown that the self-phase-modulation effect is equivalent to the process of degenerate four-wave frequency-mixing. Based on this theoretical underpinning, the presence or absence of a multipeak spectrum provides a practical measure of whether the intracavity group-velocity-dispersion is ideally compensated for or not.展开更多
基金This work was supported by the National Natural Science Foundation of China(Grant No.81027003).
文摘In this paper,a hybrid electronic noses’system(HENS)based on MOS-SAW detection units intended for lung cancer diagnosis is proposed.The MOS gas sensors are used to detect the VOC molecules with low molecular weight(LMW),and the SAW sensors are adopted for the detection of VOC with high molecular weight(HMW).Thus,the novel combination of these two kinds of gas sensors provides higher sensitivities to more of VOC species in breath than that of using only a single kind of sensor.The signals from MOS-SAW detection units are then recognized by a multi-model diagnosis method.Applying four algorithms,six models were established for diagnosis and tested by leave-one-out cross-validation method.The model by artificial neural network(ANN)was selected as the best model to analyze breath samples.89 clinical samples were tested with MOS-SAW ANN diagnostic model,which takes the features derived from both the MOS and SAW sensors.It shows the highest sensitivity of 93.62%,and the highest selectivity of 83.37%.The study shows that,promisingly,our HENS is effective during screening of lung cancer patients,especially among the people of high risk.
文摘Purpose: To explore the effect of rhIL-12 on the number of the blood cells and CD4/8+ T, CD45+ leukocytes, and CD56+ NK cells in liver cancer patients following radiation therapy. Methods: We selected forty liver cancer patients who carried out by cyber knife (the patients were given 5 Gy every time for 5 times continuously) to observe the size of the tumor. After thirty hours, rhIL-12 was injected into the liver cancer patients via subcutaneous at the concentration of 50 ng/kg, 100 ng/kg, 200 ng/kg and 300 ng/kg in different patients, respectively. And there were ten patients in the four groups, respectively. The twenty patients who were selected from the hospital without rhIL-12 treatment were used as controls. All the blood cells were collected from different groups on day 0, hour 12, day 7, day 14, day 21 and day 28 after rhIL-12 treatment, respectively. The full number of blood cells in every group was analyzed by ELISA. The number of CD4/8+ T, CD45+ leukocytes, and CD56+ NK cells were detected by Flow Cytometry. After one month with rhIL-12 treatment, ECOG and WHO were used to evaluate the prognosis of liver cancer. Results: In present study, we found that the number of blood cells was significantly decreased on day 0 - day 3, while recovered from day 7 - day 14 and down-regulated on day 21 after rhIL-12 treatment. The number of CD4/8+ T, CD45+ leukocytes, and CD56+ NK cells was elevated with any concentration of rhIL-12. Furthermore, results showed that number of white blood cells was obviously higher than in patients without rhIL-12 treatment (P < 0.05). However, there was no significant difference of erythrocyte and platelet, between groups treated with rhIL-12 and control groups. In addition, the immune cells including CD4/8+ T, CD45+ leukocytes, and CD56+ NK cells were reduced on day 0 - day 3, recovered from day 7, and then decreased from day 21 in rhIL-12 treatment groups related to control groups (P < 0.05). Furthermore, studies showed that five patients developed symptoms of fever, bilirubin increased and liver dysfunction with the dose of 300 ng/kg. So we found that the safe and well-tolerated human dose of 200 ng/kg is within this efficacious range based on exposure parameters through the research. Higher ECOG and WHO scores were observed in rhIL-12 treatment groups compared to control groups (P = 0.025, P = 0.044, respectively). Conclusion: Our results suggested that rhIL-12 could recover the liver cancer induced aberrant blood cell number and CD4/8+ T, CD45+ leukocytes, and CD56+ NK cells , which may be an effective method to alleviate the progress of liver cancer and played an important role in treating liver cancer.
基金supported by the China Postdoctoral Science Foundation(grant Nos.2019M662405,2019M650612)Natural Science Foundation of Shandong Province(grant Nos.ZR2019BF047,ZR2020KE059)+1 种基金School city integration in Zibo(grant No.2019ZBXC299)Financially Sponsored by Heilongjiang Touyan Team Program,Fundamental Research Funds for the Central Universities(grant No.HIT.OCEF.2021003).
文摘With the further requirements of electronic products and powered vehicles,the development of a new generation with low-voltage and high-capacity anode materials is crucial for lithium-ion batteries(LIBs).Transition metal phosphides,especially cobalt phosphide(CoP)composites,have become a research hotspot for LIBs anode materials in recent years due to their high theoretical specific capacity,low polarization,and suitable voltage plateau.This review first systematically discusses the lithium storage mechanism and preparation methods of CoP in current research.Subsequently,the applications of CoP anode materials in LIBs are categorically reviewed,including the composites of CoP with various types of carbon materials and heterostructures.Finally,the challenges and future development directions of CoP anode materials are summarized to provide guidance for further improving the lithium storage performance of CoP and its practical applications.
基金supported by the China Postdoctoral Science Foundation(grant Nos.2019M662405,2019M650612)Natural Science Foundationof Shandong Province(grant Nos.ZR2019BF047,ZR2020KE059)+1 种基金School city integration in Zibo(grant No.2019ZBXC299)Financially Sponsored by Heilongjiang Touyan Team Program,the Fundamental Research Funds for the Central Universities(grant No.HIT.0CEF.2021003).
文摘This review presents a summary of the research conducted thus far on the recovery of various types of valuable metals from red mud. The composition, properties, environmental hazards, and current status of comprehensive utilization of red mud were studied. A number of studies have been conducted on the use of red mud as a modifying additive for cement, the development of various catalysts based on red mud, and the recovery of various valuable metals from red mud. Furthermore, we examine several techniques for extracting various types of valuable metals from red mud, including pyrometallurgical recovery, wet leaching recovery, and emerging biobased technology recovery. We investigate the underlying principles, processes, research progress, and the potential for industrial application of these methods, and assess the advantages and disadvantages of each from the perspectives of economic and environmental benefits. Although these methods have certain disadvantages, in general, the recovery of various types of valuable metals from red mud is an effective way to solve the problem of red mud and the supply of metal raw materials. In conclusion, this paper presents an overview of the current state of red mud development and utilization, as well as the various methods employed for the recovery of valuable metals from red mud.
基金supported by the China Postdoctoral Science Foundation (grant Nos.2019M662405,2019M650612)Natural Science Foundation of Shandong Province (grant Nos.ZR2019BF047,ZR2020KE059)+1 种基金School City Integration in Zibo (grant No.2019ZBXC299)Heilongjiang Touyan Team Program,and the Fundamental Research Funds for the Central Universities (grant No.HIT.0CEF.2021003).
文摘In recent years,significant progress has been achieved in the creation of innovative functional materials for energy storage and conversion.Due to their distinct physicochemical characteristics,ultrathin nanosheets composed of common layered transition metal sulfide materials(MoS2)have demonstrated promise as high-capacity anode materials for lithium-ion batteries(LIBs).Nevertheless,their practical application is severely limited by the tendency of monolayer nanosheets to restack due to strong van der Waals forces,dramatic volume changes during successive cycles,and low intrinsic conductivity.Recent research advances have shown that composite structures and nanowire morphologies with specific morphologies effectively overcome these issues.This paper reviews the recent research progress on molybdenum disulfide-based composites as anode materials for LIBs and discusses in detail the struc-tural characteristics of pure molybdenum disulfide and other composite forms of molybdenum disulfide.In addition,the phase engineering,defect engineering,and lithium storage mechanisms of molybdenum disulfide and the synthesis of molybdenum disulfide-based nanocomposites by different preparation methods are focused on.Finally,we review the design(structure),recent developments,and challenges of novel anode materials and consider their electrochemical performance in Li-ion batteries.
基金supported by the Starting Grants of Shaanxi Normal University(grant nos.1112010209 and 1110010717)Fundamental Research Funds for the Central Universities(no.GK202103013 and 2021CSLY005)funded projects for the Academic Leader and Academic Backbones,Shaanxi Normal University(no.18QNGG006)。
文摘Manganese dioxide(MnO2)is a widely used and well-studied 3-dimensional(3D)transition metal oxide,which has advantages in ultrafast optics due to large specific surface area,narrow bandgap,multiple pores,superior electron transfer capability,and a wide range of light absorption.However,few studies have considered its excellent performance in ultrafast photonics.y-MnO2 photonics devices were fabricated based on a special dual-core,pair-hole fiber(DCPHF)carrier and applied in ultrafast optics fields for the first time.The results show that the soliton molecule with tunable temporal separation(1.84 to 2.7 ps)and 600-MHz harmonic solitons are achieved in the experiment.The result proves that this kind of photonics device has goodapplications in ultrafast lasers,high-performance sensors,fiber optical communications,etc.,which can help expand the prospect of combining 3D materials with novel fiber for ultrafast optics device technology.
基金Agence Nationale de la Recherche(ANR)(11BS09026)National Natural Science Foundation of China(NSFC)(61775236)+2 种基金LABEX MANUTECH-SISE(ANR-10-LABX-0075)Investissements d’Avenir(ANR-11-IDEX-0007)National Key Research and Development Program of China(2018YFB1107401)
文摘Ultrashort pulsed Bessel beams with intrinsic nondiffractive character and potential strong excitation confinement down to 100nm can show a series of advantages over Gaussian beams in fabricating efficient Bragg grating waveguides(BGWs).In this work, we focus on parameter management for the inscription of efficient BGWs using the point-by-point method employing Bessel beams.Due to their high aspect ratio, the resulting one-dimensional void-like structures can section the waveguides and interact efficiently with the optical modes. Effective first-order BGWs with low birefringence can then be fabricated in bulk fused silica. By controlling the size and the relative location of grating voids via the Bessel pulse energy and scan velocities, the resonant behaviors of BGWs can be well regulated.A high value of 34 dB for 8 mm length is achieved.A simple predictive model for BGWs is proposed for analyzing the influences of processing parameters on the performance of BGWs. The technique permits multiplexing several gratings in the same waveguide.Up to eight grating traces were straightforwarcliy inscribed into the waveguide in a parallel-serial combined mode, forming the multiplex BGWs.As an application, the multiplex BGW sensor with two resonant peaks is proposed and fabricated for improving the reliability of temperature detection.
基金Strategic Priority Research Program of the Chinese Academy of Sciences(CAS)(XDB 24030600)National Key Research and Development Program of China(2016YFF0200702)+1 种基金National Natural Science Foundation of China(NSFC)(61690222,61308037,61635013)CASSAFEA International Partnership Program for Creative Research Teams
文摘Dual-pumped microring-resonator-based optical frequency combs(OFCs) and their temporal characteristics are numerically investigated and experimentally explored. The calculation results obtained by solving the driven and damped nonlinear Schr?dinger equation indicate that an ultralow coupled pump power is required to excite the primary comb modes through a non-degenerate four-wave-mixing(FWM) process and, when the pump power is boosted, both the comb mode intensities and spectral bandwidths increase. At low pump powers, the field intensity profile exhibits a cosine variation manner with frequency equal to the separation of the two pumps, while a roll Turing pattern is formed resulting from the increased comb mode intensities and spectral bandwidths at high pump powers. Meanwhile, we found that the power difference between the two pump fields can be transferred to the newly generated comb modes, which are located on both sides of the pump modes, through a cascaded FWM process. Experimentally, the dual-pumped OFCs were realized by coupling two self-oscillating pump fields into a microring resonator. The numerically calculated comb spectrum is verified by generating an OFC with 2.0 THz mode spacing over 160 nm bandwidth. In addition, the formation of a roll Turing pattern at high pump powers is inferred from the measured autocorrelation trace of a 10 free spectral range(FSR) OFC. The experimental observations accord well with the numerical predictions. Due to their large and tunable mode spacing, robustness,and flexibility, the proposed dual-pumped OFCs could find potential applications in a wide range of fields,including arbitrary optical waveform generation, high-capacity optical communications, and signal-processing systems.
基金supported by the China Postdoctoral Science Foundation(Grant Nos.2019M662405 and 2019M650612)the Natural Science Foundation of Shandong Province(ZR2019BF047 and ZR2020KE059)the School City Integration in Zibo(2019ZBXC299).
文摘Tricobalt tetroxide(Co_(3)O_(4))is one of the promising anodes for lithium-ion batteries(LIBs)due to its high theoretical capacity.However,the poor electrical conductivity and the rapid capacity decay hamper its practical application.In this work,we design and fabricate a hierarchical Co_(3)O_(4)nanorods/N-doped graphene(Co_(3)0_(4)/NG)material by a facile hydrothermal method.The nitrogen-doped graphene layers could buffer the volume change of Co_(3)0_(4)nanorods during the delithium/lithium process,increase the electrical conductivity,and profit the diffusion of ions.As an anode,the Co_(3)O_(4)/NG material reveals high specific capacities of 1873.8 mA h g^(-1)after 120 cycles at 0.1 A·g^(-1)as well as 1299.5 mA·h·g^(-1)after 400 cycles at 0.5 A·g^(-1).Such superior electrochemical performances indicate that this work may provide an effective method for the design and synthesis of other metal oxide/N-doped graphene electrode materials.
基金supported by the Key-Area Research and Development Program of Guangdong Province(No.2018B090904003)National Natural Science Foundation of China(NSFC)(Nos.61805274 and 6169022)National Key R&D Program of China(No.2018YFB1108000)。
文摘In this paper,we innovatively conduct a Porro prism-based beam pointing stability promotion technique research and realize a high-performance rod-type photonic crystal fiber-based chirped pulse amplification(CPA)system,mainly including a frequency-reduced all-fiber pre-amplification stage,photonic crystal rod-based main amplification stage,and 1600 lines/mm transmission grating-pair compressor.Laser output with average power of 50 W,repetition rates of500 kHz,pulse energy of 100μJ,pulse duration of 830 fs,beam quality of M2<1.3,power fluctuation of 0.55%root mean square,and beam pointing drift of 19μrad/?C over 8 h is realized.The high-performance laser system has an enormous application potential in fundamental research and precision manufacturing fields.
基金supported by the National Natural Science Foundation of China(No.61690222)the CAS/SAFEA international Partnership Program for creative Research Teams
文摘Graphene oxide carboxylic acid(COOH), a novel two-dimensional(2D) layered material with its unique optical and electronic properties, is discovered to exhibit the saturation of optical absorption under laser illumination.Applying the liquid-phase exfoliation method, we prepare graphene oxide-COOH dispersions with deionized water and fabricate graphene oxide-COOH polyvinyl alcohol polymer composite film. We further obtain stable Q-switching pulse and mode-locked laser operation with a 22.7 MHz repetition rate and a 1.5 ps pulse duration by incorporating the graphene oxide-COOH-based saturable absorbers into the all-fiber erbium-doped fiber laser cavity. The experimental results show that the proposed graphene oxide-COOH material can act as an effective absorber for pulsed fiber lasers, which demonstrate potential applications in the area of ultrafast optics.
文摘The multi-peak spectrum of Ti: sapphire pulses observed experimentally under ultra-broad bandwidth conditions ( 【 15 fs pulse length) has been explained theoretically. It is shown that the self-phase-modulation effect is equivalent to the process of degenerate four-wave frequency-mixing. Based on this theoretical underpinning, the presence or absence of a multipeak spectrum provides a practical measure of whether the intracavity group-velocity-dispersion is ideally compensated for or not.