In complex water environments,search tasks often involve multiple Autonomous Underwater Vehicles(AUVs),and a single centralized control cannot handle the complexity and computational burden of large-scale systems.Targ...In complex water environments,search tasks often involve multiple Autonomous Underwater Vehicles(AUVs),and a single centralized control cannot handle the complexity and computational burden of large-scale systems.Target search in complex water environments has always been a major challenge in the field of underwater robots.To address this problem,this paper proposes a multi-biomimetic robot fish collaborative target search method based on Distributed Model Predictive Control(DMPC).First,we established a bionic robot fish kinematic model and a multi-biomimetic robot fish communication model;second,this paper proposed a distributed model predictive control algorithm based on the distributed search theory framework,so that the bionic robot fish can dynamically adjust their search path according to each other’s position information and search status,avoid repeated coverage or missing areas,and thus improve the search efficiency;third,we conducted simulation experiments based on DMPC,and the results showed that the proposed method has a target search success rate of more than 90%in static targets,dynamic targets,and obstacle environments.Finally,we compared this method with Centralized Model Predictive Control(CMPC)and Random Walk(RW)algorithms.The DMPC approach demonstrates significant advantages,achieving a remarkable target search success rate of 94.17%.These findings comprehensively validate the effectiveness and superiority of the proposed methodology.It can be seen that DMPC can effectively dispatch multiple bionic robot fish to work together to achieve efficient search of vast waters.It can significantly improve the flexibility,scalability,robustness and cooperation efficiency of the system and has broad application prospects.展开更多
The clinical benefit of combination therapy is significant,but it is not easy to define the mechanism of complexity and diversity.Previous studies illustrate that phillygenin(Phi)binds in the allosteric inhibit pocket...The clinical benefit of combination therapy is significant,but it is not easy to define the mechanism of complexity and diversity.Previous studies illustrate that phillygenin(Phi)binds in the allosteric inhibit pocket of protein kinase B(AKT),and swertiamarin(Swe)acts on the pleckstrin homology(PH)domain of AKT.However,the combined synergistic effect of relieving the inflammatory response has yet to be elucidated.Based on high sensitivity,specificity and fast-responsibility fluorescent sensors,the Förster resonance energy transfer(FRET)technique offers a route to provide clear insights into physiological and pathological processes.In the study,molecular docking,the fluorescent probes of Phi and Swe for FRET were designed and synthesized.FRET analysis shown that Swe and Phi concurrently acted on the PH domain and allosterically inhibited pocket of AKT,respectively.The combination of Swe and Phi significantly increased the heat stability of AKT and decreased protease-induced degeneration.In lipopolysaccharides(LPS)-induced mice and cells,the combination arrested AKT activation,nuclear factor kappa-B(NF-κB)phosphorylation,and the expression of tumor necrosis factor-α(TNF-α),interleukin(IL)-6 and IL-8.In conclusion,FRET revealed Phi and Swe concurrently targeted AKT on different domains and the combination of Phi and Swe enhanced the anti-inflammatory effect.展开更多
Existing mobile robots mostly use graph search algorithms for path planning,which suffer from relatively low planning efficiency owing to high redundancy and large computational complexity.Due to the limitations of th...Existing mobile robots mostly use graph search algorithms for path planning,which suffer from relatively low planning efficiency owing to high redundancy and large computational complexity.Due to the limitations of the neighborhood search strategy,the robots could hardly obtain the most optimal global path.A global path planning algorithm,denoted as EDG*,is proposed by expanding nodes using a well-designed expanding disconnected graph operator(EDG)in this paper.Firstly,all obstacles are marked and their corners are located through the map pre-processing.Then,the EDG operator is designed to find points in non-obstruction areas to complete the rapid expansion of disconnected nodes.Finally,the EDG*heuristic iterative algorithm is proposed.It selects the candidate node through a specific valuation function and realizes the node expansion while avoiding collision with a minimum offset.Path planning experiments were conducted in a typical indoor environment and on the public dataset CSM.The result shows that the proposed EDG*reduced the planning time by more than 90%and total length of paths reduced by more than 4.6%.Compared to A*,Dijkstra and JPS,EDG*does not show an exponential explosion effect in map size.The EDG*showed better performance in terms of path smoothness,and collision avoidance.This shows that the EDG*algorithm proposed in this paper can improve the efficiency of path planning and enhance path quality.展开更多
An agarase gene containing 1 302 bp was cloned from Microbulbifer sp. AG1. It encoded a mature protein of 413 amino acids plus a 20-residue signal peptide. The recombinant enzyme without the signal peptide was express...An agarase gene containing 1 302 bp was cloned from Microbulbifer sp. AG1. It encoded a mature protein of 413 amino acids plus a 20-residue signal peptide. The recombinant enzyme without the signal peptide was expressed and purified from Escherichia coli BL21(DE3). When agarose was used as a substrate, the optimal temperature and pH for the enzyme were 60℃ and 7.5, respectively. The recombinant agarase showed excellent thermostability with 67% and 19% of residual activities after incubation at 50℃ and 60℃ for 1 h, respectively.Except SDS, the recombinant agarase had a relatively good resistance against the detected inhibitors, detergents and urea denaturant. Thin layer chromatography analysis and enzyme assay using p-nitrophenyl-α/β-Dgalactopyranoside revealed that the recombinant agarase was a β-agarase that degraded agarose into neoagarotetraose as the main end product. The enzymatic hydrolysis products with different degree of polymerization exhibited the antioxidant activities.展开更多
We formulate and solve the problem of spherically symmetric, steady state, adiabatic accretion onto a Schwarzschild-like black hole obtained recently. We derive the general analytic expressions for the critical points...We formulate and solve the problem of spherically symmetric, steady state, adiabatic accretion onto a Schwarzschild-like black hole obtained recently. We derive the general analytic expressions for the critical points, the critical velocity, the critical speed of sound, and subsequently the mass accretion rate. The case for polytropic gas is discussed in detail. We find the parameter characterizing the breaking of Lorentz symmetry will slow down the mass accretion rate, while has no effect on the gas compression and the temperature profile below the critical radius and at the event horizon.展开更多
Berberine(BBR) is the primary alkaloid compound of the heat-clearing traditional Chinese medicine Huanglian(Coptis chinensis) and exerts regulatory effects on energy metabolism. However, the specific targets and molec...Berberine(BBR) is the primary alkaloid compound of the heat-clearing traditional Chinese medicine Huanglian(Coptis chinensis) and exerts regulatory effects on energy metabolism. However, the specific targets and molecular mechanisms are not clear. In this paper, the BBR-affected energy metabolism pathway was screened by nontargeted metabolomics, and a BBR-derived photoaffinity labeled(PAL) probe was designed to identify potential targets via a chemical proteomics approach. NDUFV1, a subunit of complex Ⅰ on mitochondria, was identified as a potential target of BBR. In the respiratory chain, BBR suppressed the activity of complex Ⅰ, reduced the electrochemical potential in the mitochondrial intermembrane and inhibited the generation of ATP and heat via competitive binding with NDUFV1. The results illustrated the underlying mechanism of BBR in the downregulation of energy metabolism.展开更多
We present the observational results from a detailed timing analysis of the black hole candidate EXO 1846-031 during its outburst in 2019 with the observations of Insight-HXMT,NICER and MAXI.This outburst can be class...We present the observational results from a detailed timing analysis of the black hole candidate EXO 1846-031 during its outburst in 2019 with the observations of Insight-HXMT,NICER and MAXI.This outburst can be classified roughly into four different states.Type-C quasi-periodic oscillations(QPOs)observed by NICER(about 0.1-6 Hz)and Insight-HXMT(about 0.7-8 Hz)are also reported in this work.Meanwhile,we study various physical quantities related to QPO frequency.The QPO rms-frequency relationship in the energy band 1-10 keV indicates that there is a turning pointing in frequency around2 Hz,which is similar to that of GRS 1915+105.A possible hypothesis for the relationship above may be related to the inclination of the source,which may require a high inclination to explain it.The relationships between QPO frequency and QPO rms,hardness,total fractional rms and count rate have also been found in other transient sources,which can indicate that the origin of type-C QPOs is non-thermal.展开更多
With a growing sample of fast radio bursts(FRBs),we investigate the energy budget of different power sources within the framework of magnetar starquake triggering mechanism.During a starquake,the energy can be release...With a growing sample of fast radio bursts(FRBs),we investigate the energy budget of different power sources within the framework of magnetar starquake triggering mechanism.During a starquake,the energy can be released in any form through strain,magnetic,rotational,and gravitational energies.The strain energy can be converted from three other kinds of energy during starquakes.The following findings are revealed:(1)The crust can store free magnetic energy of~10^(46)erg by existing toroidal fields,sustaining 10^(6)bursts with frequent starquakes occurring due to crustal instability.(2)The strain energy develops as a rigid object spins down,which can be released during a global starquake accompanied by a glitch.However,it takes a long time to accumulate enough strain energy via spindown.(3)The rotational energy of a magnetar with P■0.1 s can match the energy and luminosity budget of FRBs.(4)The budget of the total gravitational energy is high,but the mechanism and efficiency of converting this energy to radiation deserve further exploration.展开更多
Photonic waveguides are the most fundamental element for photonic integrated circuits(PICs).Waveguide properties,such as propagation loss,modal areas,nonlinear coefficients,etc.,directly determine the functionalities ...Photonic waveguides are the most fundamental element for photonic integrated circuits(PICs).Waveguide properties,such as propagation loss,modal areas,nonlinear coefficients,etc.,directly determine the functionalities and performance of PICs.Recently,the emerging waveguides with bound states in the continuum(BICs)have opened new opportunities for PICs because of their special properties in resonance and radiation.Here,we review the recent progress of PICs composed of waveguides with BICs.First,fundamentals including background physics and design rules of a BIC-based waveguide will be introduced.Next,two types of BIC-based waveguide structures,including shallowly etched dielectric and hybrid waveguides,will be presented.Lastly,the challenges and opportunities of PICs with BICs will be discussed.展开更多
Searching for primordial gravitational waves in the cosmic microwave background(CMB)polarization signal is one of the key topics in modern cosmology.Cutting-edge CMB telescopes require thousands of pixels to maximize ...Searching for primordial gravitational waves in the cosmic microwave background(CMB)polarization signal is one of the key topics in modern cosmology.Cutting-edge CMB telescopes require thousands of pixels to maximize mapping speed.Using a modular design,the telescope focal plane is simplified to several detector modules.Each module has hundreds of pixels including antenna arrays,detector arrays,and readout arrays.The antenna arrays,as the beam defining component,determine the overall optical response of the detector module.In this article,we present the developments of 6 inch broadband antenna arrays from 80 to 170 GHz for the future IHEP focal plane module.The arrays are fabricated from 426 inch silicon wafers including 456 antennas,7%more pixels than the usual design.The overall in-band cross polarization is smaller than-20 dB and the in-band beam asymmetry is smaller than 10%,fulfilling the requirements for primordial gravitational wave search.展开更多
Superluminous supernovae(SLSNe)and luminous supernovae(LSNe)exhibit extreme luminosities,which require additional energy supply mechanisms such as central engines or circumstellar interaction.In the centralengine scen...Superluminous supernovae(SLSNe)and luminous supernovae(LSNe)exhibit extreme luminosities,which require additional energy supply mechanisms such as central engines or circumstellar interaction.In the centralengine scenario,jets inject energy into the polar ejecta,modifying its evolution and shaping the explosion geometry.This study investigates the polarization signatures of jet-driven bipolar explosions in SLSNe/LSNe,where the asymmetric ejecta structure and differential photospheric evolution imprint distinct observational features.We develop a two-component ejecta model,consisting of fast-expanding polar ejecta(powered by jets)and slower equatorial ejecta.We find that polarization exhibits complex temporal evolution,where the ejecta geometry and flux asymmetry between the two regions jointly produce a double-peaked feature.In addition,the line opacity in the polar region further enhances the wavelength dependence of the polarization.Spectropolarimetric observations,particularly during early phases,can constrain the geometry and energy sources of SLSNe/LSNe,advancing our understanding of their explosion mechanisms.展开更多
基金funded by National Natural Science Foundation of China(Nos.62473236,62073196).
文摘In complex water environments,search tasks often involve multiple Autonomous Underwater Vehicles(AUVs),and a single centralized control cannot handle the complexity and computational burden of large-scale systems.Target search in complex water environments has always been a major challenge in the field of underwater robots.To address this problem,this paper proposes a multi-biomimetic robot fish collaborative target search method based on Distributed Model Predictive Control(DMPC).First,we established a bionic robot fish kinematic model and a multi-biomimetic robot fish communication model;second,this paper proposed a distributed model predictive control algorithm based on the distributed search theory framework,so that the bionic robot fish can dynamically adjust their search path according to each other’s position information and search status,avoid repeated coverage or missing areas,and thus improve the search efficiency;third,we conducted simulation experiments based on DMPC,and the results showed that the proposed method has a target search success rate of more than 90%in static targets,dynamic targets,and obstacle environments.Finally,we compared this method with Centralized Model Predictive Control(CMPC)and Random Walk(RW)algorithms.The DMPC approach demonstrates significant advantages,achieving a remarkable target search success rate of 94.17%.These findings comprehensively validate the effectiveness and superiority of the proposed methodology.It can be seen that DMPC can effectively dispatch multiple bionic robot fish to work together to achieve efficient search of vast waters.It can significantly improve the flexibility,scalability,robustness and cooperation efficiency of the system and has broad application prospects.
基金supported by the National Natural Science Foundation of China(No.81973449).
文摘The clinical benefit of combination therapy is significant,but it is not easy to define the mechanism of complexity and diversity.Previous studies illustrate that phillygenin(Phi)binds in the allosteric inhibit pocket of protein kinase B(AKT),and swertiamarin(Swe)acts on the pleckstrin homology(PH)domain of AKT.However,the combined synergistic effect of relieving the inflammatory response has yet to be elucidated.Based on high sensitivity,specificity and fast-responsibility fluorescent sensors,the Förster resonance energy transfer(FRET)technique offers a route to provide clear insights into physiological and pathological processes.In the study,molecular docking,the fluorescent probes of Phi and Swe for FRET were designed and synthesized.FRET analysis shown that Swe and Phi concurrently acted on the PH domain and allosterically inhibited pocket of AKT,respectively.The combination of Swe and Phi significantly increased the heat stability of AKT and decreased protease-induced degeneration.In lipopolysaccharides(LPS)-induced mice and cells,the combination arrested AKT activation,nuclear factor kappa-B(NF-κB)phosphorylation,and the expression of tumor necrosis factor-α(TNF-α),interleukin(IL)-6 and IL-8.In conclusion,FRET revealed Phi and Swe concurrently targeted AKT on different domains and the combination of Phi and Swe enhanced the anti-inflammatory effect.
基金Supported by National Key Research and Development Program of China(Grant No.2022YFB4700402).
文摘Existing mobile robots mostly use graph search algorithms for path planning,which suffer from relatively low planning efficiency owing to high redundancy and large computational complexity.Due to the limitations of the neighborhood search strategy,the robots could hardly obtain the most optimal global path.A global path planning algorithm,denoted as EDG*,is proposed by expanding nodes using a well-designed expanding disconnected graph operator(EDG)in this paper.Firstly,all obstacles are marked and their corners are located through the map pre-processing.Then,the EDG operator is designed to find points in non-obstruction areas to complete the rapid expansion of disconnected nodes.Finally,the EDG*heuristic iterative algorithm is proposed.It selects the candidate node through a specific valuation function and realizes the node expansion while avoiding collision with a minimum offset.Path planning experiments were conducted in a typical indoor environment and on the public dataset CSM.The result shows that the proposed EDG*reduced the planning time by more than 90%and total length of paths reduced by more than 4.6%.Compared to A*,Dijkstra and JPS,EDG*does not show an exponential explosion effect in map size.The EDG*showed better performance in terms of path smoothness,and collision avoidance.This shows that the EDG*algorithm proposed in this paper can improve the efficiency of path planning and enhance path quality.
基金The Natural Science Foundation of Fujian Province of China under contract No.2016J01162the Program for New Century Excellent Talents in Fujian Province University,China under contract No.B15139
文摘An agarase gene containing 1 302 bp was cloned from Microbulbifer sp. AG1. It encoded a mature protein of 413 amino acids plus a 20-residue signal peptide. The recombinant enzyme without the signal peptide was expressed and purified from Escherichia coli BL21(DE3). When agarose was used as a substrate, the optimal temperature and pH for the enzyme were 60℃ and 7.5, respectively. The recombinant agarase showed excellent thermostability with 67% and 19% of residual activities after incubation at 50℃ and 60℃ for 1 h, respectively.Except SDS, the recombinant agarase had a relatively good resistance against the detected inhibitors, detergents and urea denaturant. Thin layer chromatography analysis and enzyme assay using p-nitrophenyl-α/β-Dgalactopyranoside revealed that the recombinant agarase was a β-agarase that degraded agarose into neoagarotetraose as the main end product. The enzymatic hydrolysis products with different degree of polymerization exhibited the antioxidant activities.
基金Supported by National Natural Science Foundation of China under Grant No.11273010the Hebei Provincial Outstanding Youth Fund under Grant No.A2014201068+1 种基金the Outstanding Youth Fund of Hebei University under Grant No.2012JQ02the Midwest Universities Comprehensive Strength Promotion Project
文摘We formulate and solve the problem of spherically symmetric, steady state, adiabatic accretion onto a Schwarzschild-like black hole obtained recently. We derive the general analytic expressions for the critical points, the critical velocity, the critical speed of sound, and subsequently the mass accretion rate. The case for polytropic gas is discussed in detail. We find the parameter characterizing the breaking of Lorentz symmetry will slow down the mass accretion rate, while has no effect on the gas compression and the temperature profile below the critical radius and at the event horizon.
基金supported by the National Natural Science Foundation of China(No.81973449)the China Postdoctoral Science Foundation(No.2020M680871)。
文摘Berberine(BBR) is the primary alkaloid compound of the heat-clearing traditional Chinese medicine Huanglian(Coptis chinensis) and exerts regulatory effects on energy metabolism. However, the specific targets and molecular mechanisms are not clear. In this paper, the BBR-affected energy metabolism pathway was screened by nontargeted metabolomics, and a BBR-derived photoaffinity labeled(PAL) probe was designed to identify potential targets via a chemical proteomics approach. NDUFV1, a subunit of complex Ⅰ on mitochondria, was identified as a potential target of BBR. In the respiratory chain, BBR suppressed the activity of complex Ⅰ, reduced the electrochemical potential in the mitochondrial intermembrane and inhibited the generation of ATP and heat via competitive binding with NDUFV1. The results illustrated the underlying mechanism of BBR in the downregulation of energy metabolism.
基金the HXMT mission,a project funded by China National Space Administration(CNSA)and the Chinese Academy of Sciences(CAS)supported by the National Key R&D Program of China(2016YFA0400800)the National Natural Science Foundation of China(Grant Nos.11673023,U1838201,U1838115,U1838111,U1838202,11733009 and U1838108)。
文摘We present the observational results from a detailed timing analysis of the black hole candidate EXO 1846-031 during its outburst in 2019 with the observations of Insight-HXMT,NICER and MAXI.This outburst can be classified roughly into four different states.Type-C quasi-periodic oscillations(QPOs)observed by NICER(about 0.1-6 Hz)and Insight-HXMT(about 0.7-8 Hz)are also reported in this work.Meanwhile,we study various physical quantities related to QPO frequency.The QPO rms-frequency relationship in the energy band 1-10 keV indicates that there is a turning pointing in frequency around2 Hz,which is similar to that of GRS 1915+105.A possible hypothesis for the relationship above may be related to the inclination of the source,which may require a high inclination to explain it.The relationships between QPO frequency and QPO rms,hardness,total fractional rms and count rate have also been found in other transient sources,which can indicate that the origin of type-C QPOs is non-thermal.
基金supported by the National SKA Program of China(No.2020SKA0120100)the Strategic Priority Research Program of the CAS(No.XDB0550300)+1 种基金support from the National Natural Science Foundation of China(NSFC,Grant Nos.11988101 and 11933004)from the New Cornerstone Science Foundation through the New Cornerstone Investigator Program and the XPLORER PRIZE。
文摘With a growing sample of fast radio bursts(FRBs),we investigate the energy budget of different power sources within the framework of magnetar starquake triggering mechanism.During a starquake,the energy can be released in any form through strain,magnetic,rotational,and gravitational energies.The strain energy can be converted from three other kinds of energy during starquakes.The following findings are revealed:(1)The crust can store free magnetic energy of~10^(46)erg by existing toroidal fields,sustaining 10^(6)bursts with frequent starquakes occurring due to crustal instability.(2)The strain energy develops as a rigid object spins down,which can be released during a global starquake accompanied by a glitch.However,it takes a long time to accumulate enough strain energy via spindown.(3)The rotational energy of a magnetar with P■0.1 s can match the energy and luminosity budget of FRBs.(4)The budget of the total gravitational energy is high,but the mechanism and efficiency of converting this energy to radiation deserve further exploration.
基金Project supported by the National Key Research and Development Program of China (2021YFB2800404)National Natural Science Foundation of China (62105283)+1 种基金Zhejiang Provincial Natural Science Foundation of China (LDT23F04012F05)Leading Innovative and Entrepreneur Team Introduction Program of Zhejiang (2021R01001)
文摘Photonic waveguides are the most fundamental element for photonic integrated circuits(PICs).Waveguide properties,such as propagation loss,modal areas,nonlinear coefficients,etc.,directly determine the functionalities and performance of PICs.Recently,the emerging waveguides with bound states in the continuum(BICs)have opened new opportunities for PICs because of their special properties in resonance and radiation.Here,we review the recent progress of PICs composed of waveguides with BICs.First,fundamentals including background physics and design rules of a BIC-based waveguide will be introduced.Next,two types of BIC-based waveguide structures,including shallowly etched dielectric and hybrid waveguides,will be presented.Lastly,the challenges and opportunities of PICs with BICs will be discussed.
基金supported by the National Key Research and Development Program of China(grants Nos.2022YFC2205000 and 2021YFC2203400)。
文摘Searching for primordial gravitational waves in the cosmic microwave background(CMB)polarization signal is one of the key topics in modern cosmology.Cutting-edge CMB telescopes require thousands of pixels to maximize mapping speed.Using a modular design,the telescope focal plane is simplified to several detector modules.Each module has hundreds of pixels including antenna arrays,detector arrays,and readout arrays.The antenna arrays,as the beam defining component,determine the overall optical response of the detector module.In this article,we present the developments of 6 inch broadband antenna arrays from 80 to 170 GHz for the future IHEP focal plane module.The arrays are fabricated from 426 inch silicon wafers including 456 antennas,7%more pixels than the usual design.The overall in-band cross polarization is smaller than-20 dB and the in-band beam asymmetry is smaller than 10%,fulfilling the requirements for primordial gravitational wave search.
基金supported by the National Natural Science Foundation of China(Projects 12373040 and 12021003)the National SKA Program of China(2022SKA0130100)the Fundamental Research Funds for the Central Universities.
文摘Superluminous supernovae(SLSNe)and luminous supernovae(LSNe)exhibit extreme luminosities,which require additional energy supply mechanisms such as central engines or circumstellar interaction.In the centralengine scenario,jets inject energy into the polar ejecta,modifying its evolution and shaping the explosion geometry.This study investigates the polarization signatures of jet-driven bipolar explosions in SLSNe/LSNe,where the asymmetric ejecta structure and differential photospheric evolution imprint distinct observational features.We develop a two-component ejecta model,consisting of fast-expanding polar ejecta(powered by jets)and slower equatorial ejecta.We find that polarization exhibits complex temporal evolution,where the ejecta geometry and flux asymmetry between the two regions jointly produce a double-peaked feature.In addition,the line opacity in the polar region further enhances the wavelength dependence of the polarization.Spectropolarimetric observations,particularly during early phases,can constrain the geometry and energy sources of SLSNe/LSNe,advancing our understanding of their explosion mechanisms.
