Maize breeding efforts to generate high yielding and adaptive cultivars have recently been given emphasis by national maize breeding program. In Ethiopia, the maize production system is mainly dominated by subsistence...Maize breeding efforts to generate high yielding and adaptive cultivars have recently been given emphasis by national maize breeding program. In Ethiopia, the maize production system is mainly dominated by subsistence farmers where their production is below average. The objectives of this study were to determine the combining ability between lines and testers, and to evaluate the performance of crosses (hybrids) and parents for grain yield and yield component traits. Twenty-seven inbred lines were generated by crossing nine female lines (L1-L9) and three male testers (T1-T3) using line × tester mating system at International Maize and Wheat Improvement Center (CIMMYT), East African high land maize improvement program. The inbred lines along with parents were evaluated in randomized complete block design with two replications at three locations (Ambo, Kulumsa and Haramaya). Significant differences were observed among genotypes for all ten traits considered. Eight crosses (L1 × T2, L1 × T3, L3 × T3, L8 × T1, L4 × T2, L9 × T1, L2 × T1, and L2 × T2) had higher yield performance compared to other crosses across environments. Significant mean square differences were found across locations for general combining ability (GCA) due to lines for all traits except for number of kernel rows per ear, whereas GCA due to testers were significant only for grain yield, ear length and 1000-seed weight. Significant mean square due to GCA × Loc (both for lines and testers) was found for days to maturity (38.71*), 1000-seed weight (4582.36**) and grain yield (2756777**), while significant SCA × Loc interaction was found for all traits except number of kernel rows per ear (1.07), ear length (0.79) and ear diameter (0.12), suggesting that the importance of additive and non-additive gene effects in controlling these characters.展开更多
Operating out of Shanghai,Brujas Textile Tech(Shanghai)Co.,Ltd.(“Brujas”)is a wholly owned subsidiary of Guangshan White Shark Card Clothing Co.,Ltd.(“White Shark”)tasked with providing international trade service...Operating out of Shanghai,Brujas Textile Tech(Shanghai)Co.,Ltd.(“Brujas”)is a wholly owned subsidiary of Guangshan White Shark Card Clothing Co.,Ltd.(“White Shark”)tasked with providing international trade services to support its parent company's global operations.Whereas White Shark,as the parent company founded in 1962,is the manufacture facilities located in Xinyang,Henan Province.Brujas was founded in 1908 by the Brujas family in Terrassa,Spain.In 2008,White Shark integrated Brujas brand into its production and added European experience and knowledge that continues in the production today.This enables White Shark and Brujas to provide customers with the best,personalized carding solutions.White Shark and Brujas service 8700 clients in over 40 countries globally.The main products of the company include but not limited to:metallic card clothing,flat tops,stationary flat,circular comb,combing roller,cleaning fillet,raising fillet,flexible fillet etc.,and they are widely used in the areas of cotton spinning,non-woven materials,wool and linen spinning.展开更多
Strong coupling effects in magnonic systems are highly promising.They combine the advantages of different quasiparticles and enable energy transfer for coherent information processing.When driven by microwave,electric...Strong coupling effects in magnonic systems are highly promising.They combine the advantages of different quasiparticles and enable energy transfer for coherent information processing.When driven by microwave,electric,or optical pumps,these coupling effects can give rise to intriguing nonlinear phenomena,which have become a focal point in the field of magnonics.This review systematically explores pump-engineered magnon-coupling systems from three perspectives:(1)pump-induced hybridization of magnon modes,(2)nonlinear manipulation of magnon dynamics,and(3)implementation of functional magnonic devices.Unlike conventional cavity-magnon interactions that are constrained by electromagnetic boundaries,pumped coupled magnons are liberated from these restrictions.They can operate over a broad frequency band rather than being confined to discrete modes.An example is the recently discovered pump-induced magnon mode(PIM).These magnons arise from the collective excitations of unsaturated spins driven by microwave pumps.They exhibit reduced damping and photon-number-sensitive splitting characteristics,facilitating waveform-controlled coupling strength and enhanced nonlinearity—features that support phenomena such as magnonic frequency combs(MFCs).By expanding this principle to electric pumping schemes,we bridge fundamental physics and practical device applications,enabling nonreciprocal switching and meter-scale strong coupling.These advances establish high-dimensional control capabilities for coupled magnonics and pave the way for their use as a promising platform for dynamically programmable devices,magnetic-field sensing,and coherent networks.展开更多
Magnon frequency combs have garnered significant attention due to their wide-ranging potential applications,primarily generated by the interplay between spin waves and oscillating magnetic textures.Developing an easil...Magnon frequency combs have garnered significant attention due to their wide-ranging potential applications,primarily generated by the interplay between spin waves and oscillating magnetic textures.Developing an easily achievable magnon frequency comb with directly tunable comb spacing is pivotal for broadening its utility.In this study,we engineered a Bloch-type magnetic domain wall with a stable structure and fixed position by employing a dual-pinning approach utilizing artificial structural defects and stray fields.We established a magnetic domain wall oscillation mode based on resonant Larmor precession,serving as the foundation for a magnon frequency comb derived from magnetic domain walls.By leveraging the locally distributed Oersted field generated by an alternating current,we achieved precise control over the oscillation frequency of the domain wall,thereby realizing a magnon frequency comb with directly tunable comb spacing.The insights from this research offer a promising shortcut for exploring frequency combs based on the interaction between spin waves and magnetic domain walls.展开更多
We theoretically demonstrate that multipartite entanglement and one-way Einstein-Podolsky-Rosen(EPR)steering in a magnon frequency comb(MFC)can be generated in a hybrid magnon-skyrmion system.When the system is driven...We theoretically demonstrate that multipartite entanglement and one-way Einstein-Podolsky-Rosen(EPR)steering in a magnon frequency comb(MFC)can be generated in a hybrid magnon-skyrmion system.When the system is driven by two microwave fields at the magnonic whispering gallery mode(m WGM)and the skyrmion,the skyrmion can be simultaneously entangled with three magnon modes of the MFC and the entanglement of the first-order magnon pair in the MFC also appears.The results show that the perfect one-way steering between the skyrmion and the three magnons can be obtained.Interestingly,the steering direction can be manipulated by controlling the amplitudes of two drive fields,which provides flexibility in controlling the asymmetry of the EPR steering and may well have practical applications.Moreover,the genuine tripartite entanglement among the skyrmion and the first-order magnon pair can be achieved with appropriate parameters in the steady state.Our work exhibits that the MFC has great potential in preparing multi-mode entanglement resources,with promising applications in quantum communication.展开更多
Tunable mid-infrared lasers are essential for optical sensing and imaging.Existing technologies,however,face challenges in simultaneously achieving broadband spectral tunability and ultra-rapid scan rates,limiting the...Tunable mid-infrared lasers are essential for optical sensing and imaging.Existing technologies,however,face challenges in simultaneously achieving broadband spectral tunability and ultra-rapid scan rates,limiting their utility in dynamic scenarios such as real-time characterization of multiple molecular absorption bands.We present a high-speed approach for broadband wavelength sweeping in the mid-infrared region,leveraging spectral focusing via difference-frequency generation between a chirped fiber laser and an asynchronous,frequency-modulated electro-optic comb.This method enables pulse-to-pulse spectral tuning at a speed of 5.6 THz∕μs with 380 elements.Applied to spectroscopic sensing,our technique achieves broad spectral coverage(2600 to 3780 cm−1)with moderate spectral resolution(8 cm−1)and rapid acquisition time(-6.3μs).Notably,the controllable electro-optic comb facilitates high scan rates of up to 2 Mscans∕s across the full spectral range(corresponding to a speed of 60 THz∕μs),with trade-offs in number of elements(-30)and spectral point spacing or resolution(33 cm−1).Nevertheless,these capabilities make our platform highly promising for applications such as flow cytometry,chemical reaction monitoring,and mid-infrared ranging and imaging.展开更多
Purpose–The efficient utilization of recycled concrete powder(RCP)has attracted much attention.To break through the limitation of single activation technology of RCP,this study investigates the effects of a mechanica...Purpose–The efficient utilization of recycled concrete powder(RCP)has attracted much attention.To break through the limitation of single activation technology of RCP,this study investigates the effects of a mechanical-microwave method on the reactivity of RCP.Design/methodology/approach–The mechanical properties,hydration products,and pore structure of RCP-incorporated mortar were evaluated.Findings–The results demonstrate that the combined activation reduces the median particle size of RCP and induces a low-frequency shift in the Si-O-T FT-IR characteristic peaks,signifying depolymerization of the silicate network and formation of highly reactive broken bond sites.Concurrently,decreased Si2p and Al2p binding energies in XPS spectra confirm enhanced surface reactivity.The 28-day strength activity index(SAI)of RCP mortar improved from 65.7(untreated)to 82.2%under optimal activation conditions(90-min ball milling followed by 10-min microwave irradiation),outperforming solely mechanical activation by 3.6–6.1%.Furthermore,combined activation increased chemically bound water content from 22.8 to 33.7%,accompanied by a low-wavenumber shift in FT-IR peaks of hydration products.The total porosity of RCP mortar decreased from 17.2 to 14.6%,indicating a denser pore structure.Originality/value–This study explores the feasibility and potential mechanism of mechanical-microwave activation of RCP,aiming to provide valuable insights for the sustainable development of materials.Using activated RCP in cement-based materials reduces the demand for cement and substantially cuts carbon emissions,thereby making a critical contribution to the construction industry’s green and low-carbon transition.展开更多
Laser frequency combs,which are composed of a series of equally spaced coherent frequency components,have triggered revolutionary progress in precision spectroscopy and optical metrology.Length/distance is of fundamen...Laser frequency combs,which are composed of a series of equally spaced coherent frequency components,have triggered revolutionary progress in precision spectroscopy and optical metrology.Length/distance is of fundamental importance in both science and technology.We describe a ranging scheme based on chirped pulse interferometry.In contrast to the traditional spectral interferometry,the local oscillator is strongly chirped which is able to meet the measurement pulses at arbitrary distances,and therefore,the dead zones can be removed.The distances can be precisely determined via two measurement steps based on the time-of-flight method and synthetic wavelength interferometry,respectively.To overcome the speed limitation of the optical spectrum analyzer,the spectrograms are stretched and detected by a fast photodetector and oscilloscope and consequently mapped into the time domain in real time.The experimental results indicate that the measurement uncertainty can be well within±2μm,compared with the reference distance meter.The Allan deviation can reach 0.4μm at 4 ns averaging time and 25 nm at 1μs and can achieve 2 nm at 100μs averaging time.We also measured a spinning disk with grooves of different depths to verify the measurement speed,and the results show that the grooves with about 150 m∕s line speed can be clearly captured.Our method provides a unique combination of non-dead zones,ultrafast measurement speed,high precision and accuracy,large ambiguity range,and only one single comb source.This system could offer a powerful solution for field measurements in practical applications in the future.展开更多
This paper demonstrated the generation of multi-wavelength bound state noise-like pulse(BNLP)in a dispersion-managed composite-filtered fiber laser consisting of nonlinear polarization rotation(NPR)and loop.In the cas...This paper demonstrated the generation of multi-wavelength bound state noise-like pulse(BNLP)in a dispersion-managed composite-filtered fiber laser consisting of nonlinear polarization rotation(NPR)and loop.In the case of BNLP,the generation is caused by the interaction between two noise-like pulses(NLPs)induced by the comb-filtering effect,and bound state level can be artificially controlled in the researches.Our work provides a new method for generating low-coherence pulses and establishes a research idea for the study of the comb-filtering effects.展开更多
Temporal optics,which enables lossless manipulation of ultrafast pulses,offers a new dimension for the regulation of quantum optical fields.In this paper,we established a temporal Fourier transform(TF)system based on ...Temporal optics,which enables lossless manipulation of ultrafast pulses,offers a new dimension for the regulation of quantum optical fields.In this paper,we established a temporal Fourier transform(TF)system based on a four-wave mixing(FWM)time lens and constructed a full quantum theoretical model for the resulting temporal SU(1,1)interferometer.This interferometer has high temporal resolution,can impose interference in both time and frequency domains,and is sensitive to the phase derivative.By introducing linear time-varying phase modulation,we achieved sub-picosecond precision in temporal autocorrelation measurements and generatedan optical frequency comb with a fixed interval based on a feedback iteration mechanism.Theoretical analysis revealsthe crucial regulatory role of time-frequency coupling in quantum interference,providing novel solutions for ultrafast quantum imaging,temporal mode encoding,and the generation of optical frequency quantization.展开更多
Anomozamites haifanggouensis (Kimura et al.) Zheng et Zhang comb. nov. is a characteristic Bennettitalean plant in Middle Jurassic flora. Only one specimen was collected from Haifanggou Formation (Middle Jurassic) in ...Anomozamites haifanggouensis (Kimura et al.) Zheng et Zhang comb. nov. is a characteristic Bennettitalean plant in Middle Jurassic flora. Only one specimen was collected from Haifanggou Formation (Middle Jurassic) in Daohugou village, Shantou town, Ningcheng County, Nei Mongol Autonomous Region, China. The stem of plant is slender and repeatedly branches as a dichasial system with a fertile shoot in the fork, forming equal and widely divergent branches, on the branches born with the fronds of Anomozamites type. Its reproductive organs consists of some microsporophylls and a few of the bracteoid small leaves (or receptacular leaves). Some scattered bracteoid leaves and microsporophylls were formerly considered by Pan as dicots. Since then, they were proposed to be a non-committal genus Pankuangia and described them as P. haifanggouensis by Kimura et al. In this study, we discover that these bracteoid small leaves and microsporophylls should be of Anomozamites. This discovery provides strong evidence for the 'Pankuangia' determination of the taxonomical position.展开更多
[Objective] The aim was to establish a rapid method for the determination of the content of total flavonoids in the honey comb. [Method] The content of total flavonoids weas determined based on samples including comb ...[Objective] The aim was to establish a rapid method for the determination of the content of total flavonoids in the honey comb. [Method] The content of total flavonoids weas determined based on samples including comb honey, propolis, royal jelly, linden tree honey, with a polyamide column chromatography by spectrophotometry at 360 nm wavelength. [Result] The recovery rate of the method was above 90%, and the variation coefficient was lower than 2%. Compared with the traditional method, this method has less reagent consumption, simple operation and so on.[Conclusion] The content of total flavonoids in comb honey was 14.97 mg/100 g, although is only 0.87% of the total flavone content in propolis. The contained total flavonoids at least doubled than that of others and comb honey is more valuable in the content of flavonoids.展开更多
Micromachined comb-drive electrostatic resonators with folded-cantilever beams were designed and fabricated. A combination of Rayleigh＇s method and finite-element analysis was used to calculate the resonant frequency...Micromachined comb-drive electrostatic resonators with folded-cantilever beams were designed and fabricated. A combination of Rayleigh＇s method and finite-element analysis was used to calculate the resonant frequency drift as we adjusted the device geometry and material parameters. Three micromachined lateral resonant resonators with different beam widths were fabricated. Their resonant frequencies were experimentally measured to be 64.5,147.2, and 255.5kHz, respectively, which are in good agreement with the simulated resonant frequency. It is shown that an improved frequency performance could be obtained on the poly 3C-SiC based device structural material systems with high Young＇s modulus.展开更多
文摘Maize breeding efforts to generate high yielding and adaptive cultivars have recently been given emphasis by national maize breeding program. In Ethiopia, the maize production system is mainly dominated by subsistence farmers where their production is below average. The objectives of this study were to determine the combining ability between lines and testers, and to evaluate the performance of crosses (hybrids) and parents for grain yield and yield component traits. Twenty-seven inbred lines were generated by crossing nine female lines (L1-L9) and three male testers (T1-T3) using line × tester mating system at International Maize and Wheat Improvement Center (CIMMYT), East African high land maize improvement program. The inbred lines along with parents were evaluated in randomized complete block design with two replications at three locations (Ambo, Kulumsa and Haramaya). Significant differences were observed among genotypes for all ten traits considered. Eight crosses (L1 × T2, L1 × T3, L3 × T3, L8 × T1, L4 × T2, L9 × T1, L2 × T1, and L2 × T2) had higher yield performance compared to other crosses across environments. Significant mean square differences were found across locations for general combining ability (GCA) due to lines for all traits except for number of kernel rows per ear, whereas GCA due to testers were significant only for grain yield, ear length and 1000-seed weight. Significant mean square due to GCA × Loc (both for lines and testers) was found for days to maturity (38.71*), 1000-seed weight (4582.36**) and grain yield (2756777**), while significant SCA × Loc interaction was found for all traits except number of kernel rows per ear (1.07), ear length (0.79) and ear diameter (0.12), suggesting that the importance of additive and non-additive gene effects in controlling these characters.
文摘Operating out of Shanghai,Brujas Textile Tech(Shanghai)Co.,Ltd.(“Brujas”)is a wholly owned subsidiary of Guangshan White Shark Card Clothing Co.,Ltd.(“White Shark”)tasked with providing international trade services to support its parent company's global operations.Whereas White Shark,as the parent company founded in 1962,is the manufacture facilities located in Xinyang,Henan Province.Brujas was founded in 1908 by the Brujas family in Terrassa,Spain.In 2008,White Shark integrated Brujas brand into its production and added European experience and knowledge that continues in the production today.This enables White Shark and Brujas to provide customers with the best,personalized carding solutions.White Shark and Brujas service 8700 clients in over 40 countries globally.The main products of the company include but not limited to:metallic card clothing,flat tops,stationary flat,circular comb,combing roller,cleaning fillet,raising fillet,flexible fillet etc.,and they are widely used in the areas of cotton spinning,non-woven materials,wool and linen spinning.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB0580000)the National Natural Science Foundation of China(Grant Nos.12204306,12122413,12227901,12474120,and U23A6002)+4 种基金the Science and Technology Commission of Shanghai Municipality(Grant Nos.23JC1404100 and 22JC1403300)the National Key R&D Program of China(Grant Nos.2022YFA1404603 and2023YFA1406604)the Shandong Provincial Natural Science FoundationChina(Grant No.ZR2024YQ001)the Qilu Young Scholar Programs of Shandong University。
文摘Strong coupling effects in magnonic systems are highly promising.They combine the advantages of different quasiparticles and enable energy transfer for coherent information processing.When driven by microwave,electric,or optical pumps,these coupling effects can give rise to intriguing nonlinear phenomena,which have become a focal point in the field of magnonics.This review systematically explores pump-engineered magnon-coupling systems from three perspectives:(1)pump-induced hybridization of magnon modes,(2)nonlinear manipulation of magnon dynamics,and(3)implementation of functional magnonic devices.Unlike conventional cavity-magnon interactions that are constrained by electromagnetic boundaries,pumped coupled magnons are liberated from these restrictions.They can operate over a broad frequency band rather than being confined to discrete modes.An example is the recently discovered pump-induced magnon mode(PIM).These magnons arise from the collective excitations of unsaturated spins driven by microwave pumps.They exhibit reduced damping and photon-number-sensitive splitting characteristics,facilitating waveform-controlled coupling strength and enhanced nonlinearity—features that support phenomena such as magnonic frequency combs(MFCs).By expanding this principle to electric pumping schemes,we bridge fundamental physics and practical device applications,enabling nonreciprocal switching and meter-scale strong coupling.These advances establish high-dimensional control capabilities for coupled magnonics and pave the way for their use as a promising platform for dynamically programmable devices,magnetic-field sensing,and coherent networks.
基金supported by the National Natural Science Foundation of China (Grant No.12364020)the Scientific and Technological Development Plan of Jilin Province(Grant No.20240101295JC)+1 种基金the Science and Technology Research and Planning Project of Jilin Provincial Department of Education (Grant No.JJKH20230611KJ)the Applied Foundation Research Project (Talent Funding Project) of Yanbian University (Grant No.ydkj202241)。
文摘Magnon frequency combs have garnered significant attention due to their wide-ranging potential applications,primarily generated by the interplay between spin waves and oscillating magnetic textures.Developing an easily achievable magnon frequency comb with directly tunable comb spacing is pivotal for broadening its utility.In this study,we engineered a Bloch-type magnetic domain wall with a stable structure and fixed position by employing a dual-pinning approach utilizing artificial structural defects and stray fields.We established a magnetic domain wall oscillation mode based on resonant Larmor precession,serving as the foundation for a magnon frequency comb derived from magnetic domain walls.By leveraging the locally distributed Oersted field generated by an alternating current,we achieved precise control over the oscillation frequency of the domain wall,thereby realizing a magnon frequency comb with directly tunable comb spacing.The insights from this research offer a promising shortcut for exploring frequency combs based on the interaction between spin waves and magnetic domain walls.
基金supported by the National Key R&D Program of China(Grant No.2022YFA1402802)the National Natural Science Foundation of China(Grant Nos.12374103,12434003,and 12074057)。
文摘We theoretically demonstrate that multipartite entanglement and one-way Einstein-Podolsky-Rosen(EPR)steering in a magnon frequency comb(MFC)can be generated in a hybrid magnon-skyrmion system.When the system is driven by two microwave fields at the magnonic whispering gallery mode(m WGM)and the skyrmion,the skyrmion can be simultaneously entangled with three magnon modes of the MFC and the entanglement of the first-order magnon pair in the MFC also appears.The results show that the perfect one-way steering between the skyrmion and the three magnons can be obtained.Interestingly,the steering direction can be manipulated by controlling the amplitudes of two drive fields,which provides flexibility in controlling the asymmetry of the EPR steering and may well have practical applications.Moreover,the genuine tripartite entanglement among the skyrmion and the first-order magnon pair can be achieved with appropriate parameters in the steady state.Our work exhibits that the MFC has great potential in preparing multi-mode entanglement resources,with promising applications in quantum communication.
基金supported by the Innovation Program for Quantum Science and Technology(Grant No.2023ZD0301000)the Chongqing Technology Innovation and Application Develop-ment Project(Grant No.CSTB2022TIAD-DEX0031).
文摘Tunable mid-infrared lasers are essential for optical sensing and imaging.Existing technologies,however,face challenges in simultaneously achieving broadband spectral tunability and ultra-rapid scan rates,limiting their utility in dynamic scenarios such as real-time characterization of multiple molecular absorption bands.We present a high-speed approach for broadband wavelength sweeping in the mid-infrared region,leveraging spectral focusing via difference-frequency generation between a chirped fiber laser and an asynchronous,frequency-modulated electro-optic comb.This method enables pulse-to-pulse spectral tuning at a speed of 5.6 THz∕μs with 380 elements.Applied to spectroscopic sensing,our technique achieves broad spectral coverage(2600 to 3780 cm−1)with moderate spectral resolution(8 cm−1)and rapid acquisition time(-6.3μs).Notably,the controllable electro-optic comb facilitates high scan rates of up to 2 Mscans∕s across the full spectral range(corresponding to a speed of 60 THz∕μs),with trade-offs in number of elements(-30)and spectral point spacing or resolution(33 cm−1).Nevertheless,these capabilities make our platform highly promising for applications such as flow cytometry,chemical reaction monitoring,and mid-infrared ranging and imaging.
基金sponsored by Science and Technology Research and Development Plan of China National Railway Group Co.,Ltd.(L2022G009)National Natural Science Foundation of China(52438002)+1 种基金Research Project of China Academy of Railway Science Corporation Limited(2024YJ254)New Cornerstone Science Foundation through the XPLORER PRIZE.
文摘Purpose–The efficient utilization of recycled concrete powder(RCP)has attracted much attention.To break through the limitation of single activation technology of RCP,this study investigates the effects of a mechanical-microwave method on the reactivity of RCP.Design/methodology/approach–The mechanical properties,hydration products,and pore structure of RCP-incorporated mortar were evaluated.Findings–The results demonstrate that the combined activation reduces the median particle size of RCP and induces a low-frequency shift in the Si-O-T FT-IR characteristic peaks,signifying depolymerization of the silicate network and formation of highly reactive broken bond sites.Concurrently,decreased Si2p and Al2p binding energies in XPS spectra confirm enhanced surface reactivity.The 28-day strength activity index(SAI)of RCP mortar improved from 65.7(untreated)to 82.2%under optimal activation conditions(90-min ball milling followed by 10-min microwave irradiation),outperforming solely mechanical activation by 3.6–6.1%.Furthermore,combined activation increased chemically bound water content from 22.8 to 33.7%,accompanied by a low-wavenumber shift in FT-IR peaks of hydration products.The total porosity of RCP mortar decreased from 17.2 to 14.6%,indicating a denser pore structure.Originality/value–This study explores the feasibility and potential mechanism of mechanical-microwave activation of RCP,aiming to provide valuable insights for the sustainable development of materials.Using activated RCP in cement-based materials reduces the demand for cement and substantially cuts carbon emissions,thereby making a critical contribution to the construction industry’s green and low-carbon transition.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFC2204601)the National Natural Science Foundation of China(Grant Nos.11925503 and 12275093)+1 种基金the Natural Science Foundation of Hubei Province(Grant No.2021CFB019)the State Key Laboratory of Applied Optics(Grant No.SKLAO2022001A10).
文摘Laser frequency combs,which are composed of a series of equally spaced coherent frequency components,have triggered revolutionary progress in precision spectroscopy and optical metrology.Length/distance is of fundamental importance in both science and technology.We describe a ranging scheme based on chirped pulse interferometry.In contrast to the traditional spectral interferometry,the local oscillator is strongly chirped which is able to meet the measurement pulses at arbitrary distances,and therefore,the dead zones can be removed.The distances can be precisely determined via two measurement steps based on the time-of-flight method and synthetic wavelength interferometry,respectively.To overcome the speed limitation of the optical spectrum analyzer,the spectrograms are stretched and detected by a fast photodetector and oscilloscope and consequently mapped into the time domain in real time.The experimental results indicate that the measurement uncertainty can be well within±2μm,compared with the reference distance meter.The Allan deviation can reach 0.4μm at 4 ns averaging time and 25 nm at 1μs and can achieve 2 nm at 100μs averaging time.We also measured a spinning disk with grooves of different depths to verify the measurement speed,and the results show that the grooves with about 150 m∕s line speed can be clearly captured.Our method provides a unique combination of non-dead zones,ultrafast measurement speed,high precision and accuracy,large ambiguity range,and only one single comb source.This system could offer a powerful solution for field measurements in practical applications in the future.
基金supported by the Research Fund of Guangdong-Hong Kong-Macao Joint Laboratory for Intelligent Micro-Nano Optoelectronic Technology(No.2020B1212030010)。
文摘This paper demonstrated the generation of multi-wavelength bound state noise-like pulse(BNLP)in a dispersion-managed composite-filtered fiber laser consisting of nonlinear polarization rotation(NPR)and loop.In the case of BNLP,the generation is caused by the interaction between two noise-like pulses(NLPs)induced by the comb-filtering effect,and bound state level can be artificially controlled in the researches.Our work provides a new method for generating low-coherence pulses and establishes a research idea for the study of the comb-filtering effects.
文摘Temporal optics,which enables lossless manipulation of ultrafast pulses,offers a new dimension for the regulation of quantum optical fields.In this paper,we established a temporal Fourier transform(TF)system based on a four-wave mixing(FWM)time lens and constructed a full quantum theoretical model for the resulting temporal SU(1,1)interferometer.This interferometer has high temporal resolution,can impose interference in both time and frequency domains,and is sensitive to the phase derivative.By introducing linear time-varying phase modulation,we achieved sub-picosecond precision in temporal autocorrelation measurements and generatedan optical frequency comb with a fixed interval based on a feedback iteration mechanism.Theoretical analysis revealsthe crucial regulatory role of time-frequency coupling in quantum interference,providing novel solutions for ultrafast quantum imaging,temporal mode encoding,and the generation of optical frequency quantization.
文摘Anomozamites haifanggouensis (Kimura et al.) Zheng et Zhang comb. nov. is a characteristic Bennettitalean plant in Middle Jurassic flora. Only one specimen was collected from Haifanggou Formation (Middle Jurassic) in Daohugou village, Shantou town, Ningcheng County, Nei Mongol Autonomous Region, China. The stem of plant is slender and repeatedly branches as a dichasial system with a fertile shoot in the fork, forming equal and widely divergent branches, on the branches born with the fronds of Anomozamites type. Its reproductive organs consists of some microsporophylls and a few of the bracteoid small leaves (or receptacular leaves). Some scattered bracteoid leaves and microsporophylls were formerly considered by Pan as dicots. Since then, they were proposed to be a non-committal genus Pankuangia and described them as P. haifanggouensis by Kimura et al. In this study, we discover that these bracteoid small leaves and microsporophylls should be of Anomozamites. This discovery provides strong evidence for the 'Pankuangia' determination of the taxonomical position.
基金Supported by Guangzhou Municipal Colleges and Universities with Research Base Project in 2014(14CXY07)Institute of Scientific Research Projects in 2014(LK14002)the Transverse Research Project in 2014(w14001)~~
文摘[Objective] The aim was to establish a rapid method for the determination of the content of total flavonoids in the honey comb. [Method] The content of total flavonoids weas determined based on samples including comb honey, propolis, royal jelly, linden tree honey, with a polyamide column chromatography by spectrophotometry at 360 nm wavelength. [Result] The recovery rate of the method was above 90%, and the variation coefficient was lower than 2%. Compared with the traditional method, this method has less reagent consumption, simple operation and so on.[Conclusion] The content of total flavonoids in comb honey was 14.97 mg/100 g, although is only 0.87% of the total flavone content in propolis. The contained total flavonoids at least doubled than that of others and comb honey is more valuable in the content of flavonoids.
文摘Micromachined comb-drive electrostatic resonators with folded-cantilever beams were designed and fabricated. A combination of Rayleigh＇s method and finite-element analysis was used to calculate the resonant frequency drift as we adjusted the device geometry and material parameters. Three micromachined lateral resonant resonators with different beam widths were fabricated. Their resonant frequencies were experimentally measured to be 64.5,147.2, and 255.5kHz, respectively, which are in good agreement with the simulated resonant frequency. It is shown that an improved frequency performance could be obtained on the poly 3C-SiC based device structural material systems with high Young＇s modulus.
