An in-depth analysis on the cooperativity of intermolecular interactions including hydrogen bonding andπ-π stacking in 1,3,5-triamino-2,4,6-trinitrobenzene(TATB) crystal was studied. Two quantities, cooperativity ra...An in-depth analysis on the cooperativity of intermolecular interactions including hydrogen bonding andπ-π stacking in 1,3,5-triamino-2,4,6-trinitrobenzene(TATB) crystal was studied. Two quantities, cooperativity rate and energy, were defined to evaluate the nature and strength of cooperativity in a series of clusters diverging from 1D to 3D prototypes. The origin and mechanism of the cooperative effect were settled to demonstrate that the nature of cooperativity is determined by whether the non-covalent interactions compete or promote with each other, which is manifested by the changing trend of electron transfer. There exists obvious cooperative effect in intra-layer and inter-layer structures as they own the equivalent non-covalent interactions, while anti-cooperative effect is also observed if two interactions correlate with each other. On the whole, in the process of crystal formation, the apparent cooperativity is the check and balance of the two effects, which is capable to support a global interaction among all of molecules and contribute to the stabilization of system. Based on the results, one may get a new insight to understand the relationship between non-covalent interactions and low impact sensitivity.展开更多
Molecular dynamics method was employed to study the binding energies of the selected crystal planes of the 1,3,5,7-tetranitro-1,3,5,7-tetrazacyclooctane（HMX）/1,3-dimethyl-2-imidazolidinone（DMI） cocrystal in differ...Molecular dynamics method was employed to study the binding energies of the selected crystal planes of the 1,3,5,7-tetranitro-1,3,5,7-tetrazacyclooctane（HMX）/1,3-dimethyl-2-imidazolidinone（DMI） cocrystal in different molecular molar ratios. The mechanical properties were estimated in different molar ratios. Solvent effects were evaluated and the cooperativity effects were discussed in the HMX···HF···DMI ternary by using the M06-2x/6-311＋G（2df,2p） and MP2（full）/6-311＋G（2df,2p） methods. The results indicate that the substituted patterns（020） and（100） own the highest binding energies. The stabilities of cocrystals in the 1：1 and 2：1 ratios are the greatest, and thus the HMX/DMI cocrystals prefer cocrystallizing in the 1：1 and 2：1 molar ratios, which have good mechanical properties. The sensitivity change of cocrystal originates from not only the formation of intermolecular interaction but also the increment of bond dissociation energy of the N–NO2 bond. The cooperativity effect appears in the linear complex while the anti-cooperativity effect is found in the cyclic system. DMI binding to HMX is not energetically and structurally favored in the presence of HF. This is perhaps the reason that the solvent with large dielectric constant weakens the stability of the HMX/DMI cocrystals. Therefore, the solvents with low dielectric constants should be chosen in the preparation of HMX/DMI cocrystals.展开更多
A bifunctional heterogeneous catalyst containing two mutually incompatible acidic and basic sites, which exhibits cooperative catalytic behavior in the aldol condensation of acetone and various aldehydes, was synthesi...A bifunctional heterogeneous catalyst containing two mutually incompatible acidic and basic sites, which exhibits cooperative catalytic behavior in the aldol condensation of acetone and various aldehydes, was synthesized by postgrafting of 1,5,7- triazabicyclo[4.4.0] dec-5-ene （TBD, a sterically hindered organic base） onto AI-MCM-41 molecular sieve. 2009 Xiao Bing Lu. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.展开更多
Thermodynamic data were determined for the reversible binding of O 2 to two compounds of dicobalt(II) di(meso tetra phenyl)porphyrin derivatives with different lengths of diamidoaliphatic bridge (abbreviated to Co ...Thermodynamic data were determined for the reversible binding of O 2 to two compounds of dicobalt(II) di(meso tetra phenyl)porphyrin derivatives with different lengths of diamidoaliphatic bridge (abbreviated to Co 2PP 8 and Co 2PP 4) in N,N dimethylformamide at room temperature. The partial pressure of dioxygen necessary for half oxygenation ( P 1/2 ) and Hill coefficient ( n ) at 298 K were determined as follows: P 1/2 =54.2 kPa, n =2.0 for Co 2PP 8 and P 1/2 =6.8 kPa, n =1.8 for Co 2PP 4,respectively. The rate equations of reversible oxygen binding by Co 2PP 8 were determined and the reaction path was proposed. The results of thermodynamic and kinetic studies indicate that there exists strong cooperative effect during oxygenation of the compounds. The ESR observation reveals that the dioxygen complexes formed in the solutions are of superoxo (Co O - 2) type.展开更多
Here we examine the findings obtained for disaccharide/water mixtures near glass transition that involves cooperative relaxation features on kinetic by viscosity and on thermodynamic behaviour by neutron scattering. T...Here we examine the findings obtained for disaccharide/water mixtures near glass transition that involves cooperative relaxation features on kinetic by viscosity and on thermodynamic behaviour by neutron scattering. Then to address cooperative phenomena that mitigate the Debye-Waller behaviour we invoke Adam-Gibbs’ idea of a cooperative rearranging region. Neutron results suggest that the excess mean square displacement behaves as free volume and is closely connected to an elementary step of the structural relaxation. Then viscosity data evidence a breakdown of the Einstein-Debye relation, decoupling attributed to the intermolecular cooperativity.展开更多
The Arabidopsis phosphoinositide kinases PI4Kβ1 and PIP5K5 have been implicated in the control of directional vesicle trafficking underlying polar tip growth in pollen tubes. PI4Kβ1 and PIP5K5 catalyze key consecuti...The Arabidopsis phosphoinositide kinases PI4Kβ1 and PIP5K5 have been implicated in the control of directional vesicle trafficking underlying polar tip growth in pollen tubes. PI4Kβ1 and PIP5K5 catalyze key consecutive steps of phosphoinositide conversion, and it appears obvious that phosphatidylinositol-4-phosphate formed by PI4Kβ1 might act as a substrate for phosphatidylinositol-4,5-bisphosphate formation by PIP5K5. However, this hypothesis has not been experimentally addressed and distinct localization patterns of PI4Kβ1, PIP5K5, and also PI-synthases （PIS） generating phosphatidylinositol suggest additional complexity. Here, the synergistic functionality of enzymes of phosphoinositide conversion was assessed. In tobacco and Arabidopsis pollen tubes, phosphoinositides influence the apical secretion of pectin, and increased pectin deposition results in characteristic morphological alterations. Catalytically active and dominant negative variants of PI4Kβ1 and PIP5K5 were systematically co-expressed in tobacco pollen tubes and the incidence of morphologies related to enhanced pectin secretion was evaluated. The data support a proposed functional interplay of PI4Kβ1 and PIP5K5 at the trans-Golgi network, mediating directional vesicle trafficking. Co-expression experiments additionally including PIS isoforms, PIS1 or PIS2, indicate that pectin secretion is synergistically mediated by PI4Kβ1 and PIPSK5 acting on Ptdlns formed by PIS2 rather than PIS1. Possible ramifications for the preferential channeling of phosphoinositide intermediates between particular isoforms of PI pathway enzymes are discussed.展开更多
Cooperative guidance is a method for achieving combat objectives through information sharing and cooperative effects,and has emerged as a significant research area in the fields of missile guidance and systematic warf...Cooperative guidance is a method for achieving combat objectives through information sharing and cooperative effects,and has emerged as a significant research area in the fields of missile guidance and systematic warfare.This study presents a systematic review and analysis of current research on cooperative guidance.First,a bibliometric analysis is conducted on 513 articles using the Scopus database and CiteSpace software to assess keyword clustering,keyword cooccurrence,and keyword burst,and to later visualize the results.Second,fundamental theories of cooperative guidance,including relative motion modeling methods,algebraic graph theory,and multi-agent consensus theory,are summarized.Subsequently,an overview of current cooperative laws and corresponding analysis methods is provided,with categorization based on the cooperative structure and convergence performance.Finally,we summarize current research developments based on five perspectives and propose a developmental framework based on five layers(cyber,physical,decision,information,and system),discussing potential future advancements in cooperative terminal guidance.This framework emphasizes five key areas of research:networked,heterogeneous,integrated,intelligent,and group cooperations,with the goal of offering trends and insights for futurework.展开更多
Purpose–This study aims to propose a cooperative adhesion control method for trains with multiple motors electric locomotives.The method is intended to optimize the output torque of each motor,maximize the utilizatio...Purpose–This study aims to propose a cooperative adhesion control method for trains with multiple motors electric locomotives.The method is intended to optimize the output torque of each motor,maximize the utilization of train adhesion within the total torque command,reduce the train skidding/sliding phenomenon and achieve optimal adhesion utilization for each axle,thus realizing the optimal allocation of the multi-motor electric locomotives.Design/methodology/approach–In this study,a model predictive control(MPC)-based cooperative maximum adhesion tracking control method for multi-motor electric locomotives is presented.Firstly,train traction system with multiple motors is constructed in accordance with Newton’s second law.These equations include the train dynamics equations,the axle dynamics equations,and the wheel-rail adhesion coefficient equations.Then,a new MPC-based multi-axle adhesion co-optimization method is put forward.This method calculates the optimal output torque through real-time iteration based on the known reference slip speed to achieve multi-axle co-optimization under different circumstances.Findings–This paper presents a MPC system designed for the cooperative control of multi-axle adhesion.The results indicate that the proposed control system is able to optimize the adhesion of multiple axles under numerous different conditions and achieve the optimal power distribution based on the reduction of train skidding/sliding.Originality/value–This study presents a novel cooperative adhesion tracking control scheme.It is designed for multi-motor electric locomotives,which has rarely been studied before.And simulations are carried out in different conditions,including variable surfaces and motor failing.展开更多
For multi-vehicle networks,Cooperative Positioning(CP)technique has become a promising way to enhance vehicle positioning accuracy.Especially,the CP performance could be further improved by introducing Sensor-Rich Veh...For multi-vehicle networks,Cooperative Positioning(CP)technique has become a promising way to enhance vehicle positioning accuracy.Especially,the CP performance could be further improved by introducing Sensor-Rich Vehicles(SRVs)into CP networks,which is called SRV-aided CP.However,the CP system may split into several sub-clusters that cannot be connected with each other in dense urban environments,in which the sub-clusters with few SRVs will suffer from degradation of CP performance.Since Unmanned Aerial Vehicles(UAVs)have been widely used to aid vehicular communications,we intend to utilize UAVs to assist sub-clusters in CP.In this paper,a UAV-aided CP network is constructed to fully utilize information from SRVs.First,the inter-node connection structure among the UAV and vehicles is designed to share available information from SRVs.After that,the clustering optimization strategy is proposed,in which the UAV cooperates with the high-precision sub-cluster to obtain available information from SRVs,and then broadcasts this positioning-related information to other low-precision sub-clusters.Finally,the Locally-Centralized Factor Graph Optimization(LC-FGO)algorithm is designed to fuse positioning information from cooperators.Simulation results indicate that the positioning accuracy of the CP system could be improved by fully utilizing positioning-related information from SRVs.展开更多
To address the problem of multi-missile cooperative interception against maneuvering targets at a prespecified impact time and desired Line-of-Sight(LOS)angles in ThreeDimensional(3D)space,this paper proposes a 3D lea...To address the problem of multi-missile cooperative interception against maneuvering targets at a prespecified impact time and desired Line-of-Sight(LOS)angles in ThreeDimensional(3D)space,this paper proposes a 3D leader-following cooperative interception guidance law.First,in the LOS direction of the leader,an impact time-controlled guidance law is derived based on the fixed-time stability theory,which enables the leader to complete the interception task at a prespecified impact time.Next,in the LOS direction of the followers,by introducing a time consensus tracking error function,a fixed-time consensus tracking guidance law is investigated to guarantee the consensus tracking convergence of the time-to-go.Then,in the direction normal to the LOS,by combining the designed global integral sliding mode surface and the second-order Sliding Mode Control(SMC)theory,an innovative 3D LOS-angle-constrained interception guidance law is developed,which eliminates the reaching phase in the traditional sliding mode guidance laws and effectively saves energy consumption.Moreover,it effectively suppresses the chattering phenomenon while avoiding the singularity issue,and compensates for unknown interference caused by target maneuvering online,making it convenient for practical engineering applications.Finally,theoretical proof analysis and multiple sets of numerical simulation results verify the effectiveness,superiority,and robustness of the investigated guidance law.展开更多
When the maneuverability of a pursuer is not significantly higher than that of an evader,it will be difficult to intercept the evader with only one pursuer.Therefore,this article adopts a two-to-one differential game ...When the maneuverability of a pursuer is not significantly higher than that of an evader,it will be difficult to intercept the evader with only one pursuer.Therefore,this article adopts a two-to-one differential game strategy,the game of kind is generally considered to be angle-optimized,which allows unlimited turns,but these practices do not take into account the effect of acceleration,which does not correspond to the actual situation,thus,based on the angle-optimized,the acceleration optimization and the acceleration upper bound constraint are added into the game for consideration.A two-to-one differential game problem is proposed in the three-dimensional space,and an improved multi-objective grey wolf optimization(IMOGWO)algorithm is proposed to solve the optimal game point of this problem.With the equations that describe the relative motions between the pursuers and the evader in the three-dimensional space,a multi-objective function with constraints is given as the performance index to design an optimal strategy for the differential game.Then the optimal game point is solved by using the IMOGWO algorithm.It is proved based on Markov chains that with the IMOGWO,the Pareto solution set is the solution of the differential game.Finally,it is verified through simulations that the pursuers can capture the escapee,and via comparative experiments,it is shown that the IMOGWO algorithm performs well in terms of running time and memory usage.展开更多
The distributed permutation flow shop scheduling problem(DPFSP)has received increasing attention in recent years.The iterated greedy algorithm(IGA)serves as a powerful optimizer for addressing such a problem because o...The distributed permutation flow shop scheduling problem(DPFSP)has received increasing attention in recent years.The iterated greedy algorithm(IGA)serves as a powerful optimizer for addressing such a problem because of its straightforward,single-solution evolution framework.However,a potential draw-back of IGA is the lack of utilization of historical information,which could lead to an imbalance between exploration and exploitation,especially in large-scale DPFSPs.As a consequence,this paper develops an IGA with memory and learning mechanisms(MLIGA)to efficiently solve the DPFSP targeted at the mini-malmakespan.InMLIGA,we incorporate a memory mechanism to make a more informed selection of the initial solution at each stage of the search,by extending,reconstructing,and reinforcing the information from previous solutions.In addition,we design a twolayer cooperative reinforcement learning approach to intelligently determine the key parameters of IGA and the operations of the memory mechanism.Meanwhile,to ensure that the experience generated by each perturbation operator is fully learned and to reduce the prior parameters of MLIGA,a probability curve-based acceptance criterion is proposed by combining a cube root function with custom rules.At last,a discrete adaptive learning rate is employed to enhance the stability of the memory and learningmechanisms.Complete ablation experiments are utilized to verify the effectiveness of the memory mechanism,and the results show that this mechanism is capable of improving the performance of IGA to a large extent.Furthermore,through comparative experiments involving MLIGA and five state-of-the-art algorithms on 720 benchmarks,we have discovered that MLI-GA demonstrates significant potential for solving large-scale DPFSPs.This indicates that MLIGA is well-suited for real-world distributed flow shop scheduling.展开更多
BACKGROUND Diabetic foot ulcers(DFUs)are a significant contributor to disability and mortality in diabetic patients.Macrophage polarization and functional regulation are promising areas of research and show therapeuti...BACKGROUND Diabetic foot ulcers(DFUs)are a significant contributor to disability and mortality in diabetic patients.Macrophage polarization and functional regulation are promising areas of research and show therapeutic potential in the field of DFU healing.However,the complex mechanism,the difficulty in clinical translation,and the large heterogeneity present significant challenges.Hence,this study was to comprehensively analyze the publication status and trends of studies on macrophage polarization and DFU healing.AIM To examine the relevant literature on macrophage polarization in DFU healing.METHODS A bibliometric analysis was conducted using the Web of Science database.Relevant literature was retrieved from the Web of Science Core Collection database between 2013 to 2023 using literature visualization and analysis software(VOSviewer and CiteSpace)and bibliometric online platforms.The obtained literature was then subjected to visualization and analysis of different countries/regions,institutions,journals,authors,and keywords to reveal the research’s major trends and focus.RESULTS The number of publications on the role of macrophage polarization in DFU healing increased rapidly from 2013 to 2023,especially in the latter period.Chinese researchers were the most prolific in this field,with 217 publications,while American researchers had been engaged in this field for a longer period.Qian Tan of Nanjing Drum Tower Hospital and Qian Ding of Nanjing University were the first to publish in this field.Shanghai Jiao Tong University was the institution with the most publications(27).The keywords“bone marrow”,“adjustment,replacement,response,tissue repair”,and“activation,repair,differentiation”appeared more frequently.The study of macrophage polarization in DFU healing focused on the regulatory mechanism,gene expression,and other aspects.CONCLUSION This study through the bibliometric method reveals the research trends and development trends in this field of macrophage polarization in DFU healing from 2013 to 2023 in the Web of Science Core Collection database.The key hotspots in this field mainly include the regulation of macrophage activation,gene expression,wound tissue repair,and new wound materials.This study provides references for future research directions.展开更多
This year marks the 50th anniversary of the establishment of China-Thailand diplomatic relations and the“Golden Jubilee of China-Thailand Friendship.”Over the decades,fruitful results have been achieved in bilateral...This year marks the 50th anniversary of the establishment of China-Thailand diplomatic relations and the“Golden Jubilee of China-Thailand Friendship.”Over the decades,fruitful results have been achieved in bilateral cooperation in fields such as politics,economics,security,and cultural exchange.So,what are the key factors contributing to the enduring friendship and the remarkable achievements in bilateral cooperation?And,how does strengthened comprehensive strategic partnership and joint construction of a more stable,prosperous,and sustainable China-Thailand community with a shared future benefit both countries,the region,and even the world?展开更多
Fatty acid binding and oxidation kinetics for wild type P450_(BM3)(CYP102A1)from Bacillus megaterium have been found to display chain length-dependent homotropic behavior.Laurate and 13-methyl-myristate display Michae...Fatty acid binding and oxidation kinetics for wild type P450_(BM3)(CYP102A1)from Bacillus megaterium have been found to display chain length-dependent homotropic behavior.Laurate and 13-methyl-myristate display Michaelis-Menten behavior while there are slight deviations with myristate at low ionic strengths.Palmitate shows Michaelis-Menten kinetics and hyperbolic binding behavior in 100 mmol/L phosphate,pH 7.4,but sigmoidal kinetics(with an apparent intercept)in low ionic strength buffers and at physiological phosphate concentrations.In low ionic strength buffers both the heme domain and the full-length enzyme show complex palmitate binding behavior that indicates a minimum of four fatty acid binding sites,with high cooperativity for the binding of the fourth palmitate molecule,and the full-length enzyme showing tighter palmitate binding than the heme domain.The first flavin-to-heme electron transfer is faster for laurate,myristate and palmitate in 100 mmol/L phosphate than in 50mmol/L Tris(pH 7.4),yet each substrate induces similar high-spin heme content.For palmitate in low phosphate buffer concentrations,the rate constant of the first electron transfer is much larger than kcat.The results suggest that phosphate has a specific effect in promoting the first electron transfer step,and that P450_(BM3) could modulate Bacillus membrane morphology and fluidity via palmitate oxidation in response to the external phosphate concentration.展开更多
Both China and Indonesia are influential maritime powers in the Asia-Pacific region.Strengthening practical maritime cooperation is highly significant to both sides as an important component of comprehensive strategic...Both China and Indonesia are influential maritime powers in the Asia-Pacific region.Strengthening practical maritime cooperation is highly significant to both sides as an important component of comprehensive strategic cooperation.Maritime cooperation has become a prominent part of the“five pillar”cooperation framework between the two countries alongside political,economic,people-to-people exchange,and security,playing a positive role in elevating the China-Indonesia comprehensive strategic partnership to a higher level.展开更多
The year 2025 marks the 50th anniversary of the establishment of diplomatic relations between China and Thailand,as well as the“Golden Jubilee of Sino-Thai Friendship”.Over the past half-century,the scale and scope ...The year 2025 marks the 50th anniversary of the establishment of diplomatic relations between China and Thailand,as well as the“Golden Jubilee of Sino-Thai Friendship”.Over the past half-century,the scale and scope of economic and trade cooperation between China and Thailand have dramatically expanded.Both nations have strengthened their bilateral economic ties,which have increasingly strengthened their interdependence and.complementarity,presenting a broad prospect of mutual benefit and win-win cooperation.展开更多
Since the resumption of diplomatic relations between China and Indonesia in the 1990s,the economic and trade cooperation between the two countries has developed rapidly and continuously.Since 2013,the scale of trade b...Since the resumption of diplomatic relations between China and Indonesia in the 1990s,the economic and trade cooperation between the two countries has developed rapidly and continuously.Since 2013,the scale of trade between the two countries has expanded year on year,and investment has broadened from traditional agriculture and industry to the digital economy and financial insurance,which has effectively promoted industrial development in both countries.More infrastructure cooperation has significantly improved the development environment in Indonesia,producing tangible benefits for the local people.Different types of special economic zones have facilitated breakthrough development for Indonesian industries while creating employment opportunities for local residents and driving local economic development.展开更多
On September 1st,the 18th Chi na-LAC Business Summit Promotion Conference opened in Beijing.Chinese and foreign vips gathered to prepare for the 18th China LAC Business Summit,planned for Zhengzhou,Henan,from Novemb...On September 1st,the 18th Chi na-LAC Business Summit Promotion Conference opened in Beijing.Chinese and foreign vips gathered to prepare for the 18th China LAC Business Summit,planned for Zhengzhou,Henan,from November 3rd to 4th.展开更多
基金the support from the National Natural Science Foundation of China (No. 21875184)the Natural Science Foundation of Shaanxi Province (No. 2022JC-10)Youth Talent of Shaanxi “TeZhi” Program。
文摘An in-depth analysis on the cooperativity of intermolecular interactions including hydrogen bonding andπ-π stacking in 1,3,5-triamino-2,4,6-trinitrobenzene(TATB) crystal was studied. Two quantities, cooperativity rate and energy, were defined to evaluate the nature and strength of cooperativity in a series of clusters diverging from 1D to 3D prototypes. The origin and mechanism of the cooperative effect were settled to demonstrate that the nature of cooperativity is determined by whether the non-covalent interactions compete or promote with each other, which is manifested by the changing trend of electron transfer. There exists obvious cooperative effect in intra-layer and inter-layer structures as they own the equivalent non-covalent interactions, while anti-cooperative effect is also observed if two interactions correlate with each other. On the whole, in the process of crystal formation, the apparent cooperativity is the check and balance of the two effects, which is capable to support a global interaction among all of molecules and contribute to the stabilization of system. Based on the results, one may get a new insight to understand the relationship between non-covalent interactions and low impact sensitivity.
文摘Molecular dynamics method was employed to study the binding energies of the selected crystal planes of the 1,3,5,7-tetranitro-1,3,5,7-tetrazacyclooctane（HMX）/1,3-dimethyl-2-imidazolidinone（DMI） cocrystal in different molecular molar ratios. The mechanical properties were estimated in different molar ratios. Solvent effects were evaluated and the cooperativity effects were discussed in the HMX···HF···DMI ternary by using the M06-2x/6-311＋G（2df,2p） and MP2（full）/6-311＋G（2df,2p） methods. The results indicate that the substituted patterns（020） and（100） own the highest binding energies. The stabilities of cocrystals in the 1：1 and 2：1 ratios are the greatest, and thus the HMX/DMI cocrystals prefer cocrystallizing in the 1：1 and 2：1 molar ratios, which have good mechanical properties. The sensitivity change of cocrystal originates from not only the formation of intermolecular interaction but also the increment of bond dissociation energy of the N–NO2 bond. The cooperativity effect appears in the linear complex while the anti-cooperativity effect is found in the cyclic system. DMI binding to HMX is not energetically and structurally favored in the presence of HF. This is perhaps the reason that the solvent with large dielectric constant weakens the stability of the HMX/DMI cocrystals. Therefore, the solvents with low dielectric constants should be chosen in the preparation of HMX/DMI cocrystals.
基金support by a Foundation for the Author of National Excellent Doctoral Dissertation of China(No.FANEDD,200759)the Outstanding Young Scientist Foundation of NSFC(No.20625414)
文摘A bifunctional heterogeneous catalyst containing two mutually incompatible acidic and basic sites, which exhibits cooperative catalytic behavior in the aldol condensation of acetone and various aldehydes, was synthesized by postgrafting of 1,5,7- triazabicyclo[4.4.0] dec-5-ene （TBD, a sterically hindered organic base） onto AI-MCM-41 molecular sieve. 2009 Xiao Bing Lu. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
文摘Thermodynamic data were determined for the reversible binding of O 2 to two compounds of dicobalt(II) di(meso tetra phenyl)porphyrin derivatives with different lengths of diamidoaliphatic bridge (abbreviated to Co 2PP 8 and Co 2PP 4) in N,N dimethylformamide at room temperature. The partial pressure of dioxygen necessary for half oxygenation ( P 1/2 ) and Hill coefficient ( n ) at 298 K were determined as follows: P 1/2 =54.2 kPa, n =2.0 for Co 2PP 8 and P 1/2 =6.8 kPa, n =1.8 for Co 2PP 4,respectively. The rate equations of reversible oxygen binding by Co 2PP 8 were determined and the reaction path was proposed. The results of thermodynamic and kinetic studies indicate that there exists strong cooperative effect during oxygenation of the compounds. The ESR observation reveals that the dioxygen complexes formed in the solutions are of superoxo (Co O - 2) type.
文摘Here we examine the findings obtained for disaccharide/water mixtures near glass transition that involves cooperative relaxation features on kinetic by viscosity and on thermodynamic behaviour by neutron scattering. Then to address cooperative phenomena that mitigate the Debye-Waller behaviour we invoke Adam-Gibbs’ idea of a cooperative rearranging region. Neutron results suggest that the excess mean square displacement behaves as free volume and is closely connected to an elementary step of the structural relaxation. Then viscosity data evidence a breakdown of the Einstein-Debye relation, decoupling attributed to the intermolecular cooperativity.
文摘The Arabidopsis phosphoinositide kinases PI4Kβ1 and PIP5K5 have been implicated in the control of directional vesicle trafficking underlying polar tip growth in pollen tubes. PI4Kβ1 and PIP5K5 catalyze key consecutive steps of phosphoinositide conversion, and it appears obvious that phosphatidylinositol-4-phosphate formed by PI4Kβ1 might act as a substrate for phosphatidylinositol-4,5-bisphosphate formation by PIP5K5. However, this hypothesis has not been experimentally addressed and distinct localization patterns of PI4Kβ1, PIP5K5, and also PI-synthases （PIS） generating phosphatidylinositol suggest additional complexity. Here, the synergistic functionality of enzymes of phosphoinositide conversion was assessed. In tobacco and Arabidopsis pollen tubes, phosphoinositides influence the apical secretion of pectin, and increased pectin deposition results in characteristic morphological alterations. Catalytically active and dominant negative variants of PI4Kβ1 and PIP5K5 were systematically co-expressed in tobacco pollen tubes and the incidence of morphologies related to enhanced pectin secretion was evaluated. The data support a proposed functional interplay of PI4Kβ1 and PIP5K5 at the trans-Golgi network, mediating directional vesicle trafficking. Co-expression experiments additionally including PIS isoforms, PIS1 or PIS2, indicate that pectin secretion is synergistically mediated by PI4Kβ1 and PIPSK5 acting on Ptdlns formed by PIS2 rather than PIS1. Possible ramifications for the preferential channeling of phosphoinositide intermediates between particular isoforms of PI pathway enzymes are discussed.
基金supported by the National Natural Science Foundation of China(No.62173274)the National Key R&D Program of China(No.2019YFA0405300)+4 种基金the Natural Science Foundation of Hunan Province of China(Nos.2021JJ10045 and 2025JJ60072)the Open Research Subject of State Key Laboratory of Intelligent Game(No.ZBKF-24-01)the Postdoctoral Fellowship Program of CPSF(No.GZB20240989)the China Postdoctoral Science Foundation(No.2024M754304)the Aeronautical Science Foundation of China(No.2023Z005030001).
文摘Cooperative guidance is a method for achieving combat objectives through information sharing and cooperative effects,and has emerged as a significant research area in the fields of missile guidance and systematic warfare.This study presents a systematic review and analysis of current research on cooperative guidance.First,a bibliometric analysis is conducted on 513 articles using the Scopus database and CiteSpace software to assess keyword clustering,keyword cooccurrence,and keyword burst,and to later visualize the results.Second,fundamental theories of cooperative guidance,including relative motion modeling methods,algebraic graph theory,and multi-agent consensus theory,are summarized.Subsequently,an overview of current cooperative laws and corresponding analysis methods is provided,with categorization based on the cooperative structure and convergence performance.Finally,we summarize current research developments based on five perspectives and propose a developmental framework based on five layers(cyber,physical,decision,information,and system),discussing potential future advancements in cooperative terminal guidance.This framework emphasizes five key areas of research:networked,heterogeneous,integrated,intelligent,and group cooperations,with the goal of offering trends and insights for futurework.
基金supported by Scientific Research Projects of China Association of Metros(CAMET-KY-2022039)State Key Laboratory of Traction and Control System of EMU and Locomotive(2023YJ386).
文摘Purpose–This study aims to propose a cooperative adhesion control method for trains with multiple motors electric locomotives.The method is intended to optimize the output torque of each motor,maximize the utilization of train adhesion within the total torque command,reduce the train skidding/sliding phenomenon and achieve optimal adhesion utilization for each axle,thus realizing the optimal allocation of the multi-motor electric locomotives.Design/methodology/approach–In this study,a model predictive control(MPC)-based cooperative maximum adhesion tracking control method for multi-motor electric locomotives is presented.Firstly,train traction system with multiple motors is constructed in accordance with Newton’s second law.These equations include the train dynamics equations,the axle dynamics equations,and the wheel-rail adhesion coefficient equations.Then,a new MPC-based multi-axle adhesion co-optimization method is put forward.This method calculates the optimal output torque through real-time iteration based on the known reference slip speed to achieve multi-axle co-optimization under different circumstances.Findings–This paper presents a MPC system designed for the cooperative control of multi-axle adhesion.The results indicate that the proposed control system is able to optimize the adhesion of multiple axles under numerous different conditions and achieve the optimal power distribution based on the reduction of train skidding/sliding.Originality/value–This study presents a novel cooperative adhesion tracking control scheme.It is designed for multi-motor electric locomotives,which has rarely been studied before.And simulations are carried out in different conditions,including variable surfaces and motor failing.
基金supported by the National Natural Science Foundation of China(No.62271399)the National Key Research and Development Program of China(No.2022YFB1807102)。
文摘For multi-vehicle networks,Cooperative Positioning(CP)technique has become a promising way to enhance vehicle positioning accuracy.Especially,the CP performance could be further improved by introducing Sensor-Rich Vehicles(SRVs)into CP networks,which is called SRV-aided CP.However,the CP system may split into several sub-clusters that cannot be connected with each other in dense urban environments,in which the sub-clusters with few SRVs will suffer from degradation of CP performance.Since Unmanned Aerial Vehicles(UAVs)have been widely used to aid vehicular communications,we intend to utilize UAVs to assist sub-clusters in CP.In this paper,a UAV-aided CP network is constructed to fully utilize information from SRVs.First,the inter-node connection structure among the UAV and vehicles is designed to share available information from SRVs.After that,the clustering optimization strategy is proposed,in which the UAV cooperates with the high-precision sub-cluster to obtain available information from SRVs,and then broadcasts this positioning-related information to other low-precision sub-clusters.Finally,the Locally-Centralized Factor Graph Optimization(LC-FGO)algorithm is designed to fuse positioning information from cooperators.Simulation results indicate that the positioning accuracy of the CP system could be improved by fully utilizing positioning-related information from SRVs.
文摘To address the problem of multi-missile cooperative interception against maneuvering targets at a prespecified impact time and desired Line-of-Sight(LOS)angles in ThreeDimensional(3D)space,this paper proposes a 3D leader-following cooperative interception guidance law.First,in the LOS direction of the leader,an impact time-controlled guidance law is derived based on the fixed-time stability theory,which enables the leader to complete the interception task at a prespecified impact time.Next,in the LOS direction of the followers,by introducing a time consensus tracking error function,a fixed-time consensus tracking guidance law is investigated to guarantee the consensus tracking convergence of the time-to-go.Then,in the direction normal to the LOS,by combining the designed global integral sliding mode surface and the second-order Sliding Mode Control(SMC)theory,an innovative 3D LOS-angle-constrained interception guidance law is developed,which eliminates the reaching phase in the traditional sliding mode guidance laws and effectively saves energy consumption.Moreover,it effectively suppresses the chattering phenomenon while avoiding the singularity issue,and compensates for unknown interference caused by target maneuvering online,making it convenient for practical engineering applications.Finally,theoretical proof analysis and multiple sets of numerical simulation results verify the effectiveness,superiority,and robustness of the investigated guidance law.
基金National Natural Science Foundation of China(NSFC61773142,NSFC62303136)。
文摘When the maneuverability of a pursuer is not significantly higher than that of an evader,it will be difficult to intercept the evader with only one pursuer.Therefore,this article adopts a two-to-one differential game strategy,the game of kind is generally considered to be angle-optimized,which allows unlimited turns,but these practices do not take into account the effect of acceleration,which does not correspond to the actual situation,thus,based on the angle-optimized,the acceleration optimization and the acceleration upper bound constraint are added into the game for consideration.A two-to-one differential game problem is proposed in the three-dimensional space,and an improved multi-objective grey wolf optimization(IMOGWO)algorithm is proposed to solve the optimal game point of this problem.With the equations that describe the relative motions between the pursuers and the evader in the three-dimensional space,a multi-objective function with constraints is given as the performance index to design an optimal strategy for the differential game.Then the optimal game point is solved by using the IMOGWO algorithm.It is proved based on Markov chains that with the IMOGWO,the Pareto solution set is the solution of the differential game.Finally,it is verified through simulations that the pursuers can capture the escapee,and via comparative experiments,it is shown that the IMOGWO algorithm performs well in terms of running time and memory usage.
基金supported in part by the National Key Research and Development Program of China under Grant No.2021YFF0901300in part by the National Natural Science Foundation of China under Grant Nos.62173076 and 72271048.
文摘The distributed permutation flow shop scheduling problem(DPFSP)has received increasing attention in recent years.The iterated greedy algorithm(IGA)serves as a powerful optimizer for addressing such a problem because of its straightforward,single-solution evolution framework.However,a potential draw-back of IGA is the lack of utilization of historical information,which could lead to an imbalance between exploration and exploitation,especially in large-scale DPFSPs.As a consequence,this paper develops an IGA with memory and learning mechanisms(MLIGA)to efficiently solve the DPFSP targeted at the mini-malmakespan.InMLIGA,we incorporate a memory mechanism to make a more informed selection of the initial solution at each stage of the search,by extending,reconstructing,and reinforcing the information from previous solutions.In addition,we design a twolayer cooperative reinforcement learning approach to intelligently determine the key parameters of IGA and the operations of the memory mechanism.Meanwhile,to ensure that the experience generated by each perturbation operator is fully learned and to reduce the prior parameters of MLIGA,a probability curve-based acceptance criterion is proposed by combining a cube root function with custom rules.At last,a discrete adaptive learning rate is employed to enhance the stability of the memory and learningmechanisms.Complete ablation experiments are utilized to verify the effectiveness of the memory mechanism,and the results show that this mechanism is capable of improving the performance of IGA to a large extent.Furthermore,through comparative experiments involving MLIGA and five state-of-the-art algorithms on 720 benchmarks,we have discovered that MLI-GA demonstrates significant potential for solving large-scale DPFSPs.This indicates that MLIGA is well-suited for real-world distributed flow shop scheduling.
基金Supported by the Qilu Medical School Traditional Chinese Medicine Academic School Inheritance Project,No.93 LW[2022]Construction Project of the Inheritance Studio of National Famous Traditional Chinese Medicine Experts,Traditional Chinese Medicine Teaching Letter No.75[2022]Qilu Health and Fitness Talents in 2019,No.3 LWRZ[2020].
文摘BACKGROUND Diabetic foot ulcers(DFUs)are a significant contributor to disability and mortality in diabetic patients.Macrophage polarization and functional regulation are promising areas of research and show therapeutic potential in the field of DFU healing.However,the complex mechanism,the difficulty in clinical translation,and the large heterogeneity present significant challenges.Hence,this study was to comprehensively analyze the publication status and trends of studies on macrophage polarization and DFU healing.AIM To examine the relevant literature on macrophage polarization in DFU healing.METHODS A bibliometric analysis was conducted using the Web of Science database.Relevant literature was retrieved from the Web of Science Core Collection database between 2013 to 2023 using literature visualization and analysis software(VOSviewer and CiteSpace)and bibliometric online platforms.The obtained literature was then subjected to visualization and analysis of different countries/regions,institutions,journals,authors,and keywords to reveal the research’s major trends and focus.RESULTS The number of publications on the role of macrophage polarization in DFU healing increased rapidly from 2013 to 2023,especially in the latter period.Chinese researchers were the most prolific in this field,with 217 publications,while American researchers had been engaged in this field for a longer period.Qian Tan of Nanjing Drum Tower Hospital and Qian Ding of Nanjing University were the first to publish in this field.Shanghai Jiao Tong University was the institution with the most publications(27).The keywords“bone marrow”,“adjustment,replacement,response,tissue repair”,and“activation,repair,differentiation”appeared more frequently.The study of macrophage polarization in DFU healing focused on the regulatory mechanism,gene expression,and other aspects.CONCLUSION This study through the bibliometric method reveals the research trends and development trends in this field of macrophage polarization in DFU healing from 2013 to 2023 in the Web of Science Core Collection database.The key hotspots in this field mainly include the regulation of macrophage activation,gene expression,wound tissue repair,and new wound materials.This study provides references for future research directions.
文摘This year marks the 50th anniversary of the establishment of China-Thailand diplomatic relations and the“Golden Jubilee of China-Thailand Friendship.”Over the decades,fruitful results have been achieved in bilateral cooperation in fields such as politics,economics,security,and cultural exchange.So,what are the key factors contributing to the enduring friendship and the remarkable achievements in bilateral cooperation?And,how does strengthened comprehensive strategic partnership and joint construction of a more stable,prosperous,and sustainable China-Thailand community with a shared future benefit both countries,the region,and even the world?
基金supported by grants from the Natural Sciences and Engineering Research Council(NSERC)Canada,and the Rhodes Trust(JY)the Higher Educational Funding Council for England.
文摘Fatty acid binding and oxidation kinetics for wild type P450_(BM3)(CYP102A1)from Bacillus megaterium have been found to display chain length-dependent homotropic behavior.Laurate and 13-methyl-myristate display Michaelis-Menten behavior while there are slight deviations with myristate at low ionic strengths.Palmitate shows Michaelis-Menten kinetics and hyperbolic binding behavior in 100 mmol/L phosphate,pH 7.4,but sigmoidal kinetics(with an apparent intercept)in low ionic strength buffers and at physiological phosphate concentrations.In low ionic strength buffers both the heme domain and the full-length enzyme show complex palmitate binding behavior that indicates a minimum of four fatty acid binding sites,with high cooperativity for the binding of the fourth palmitate molecule,and the full-length enzyme showing tighter palmitate binding than the heme domain.The first flavin-to-heme electron transfer is faster for laurate,myristate and palmitate in 100 mmol/L phosphate than in 50mmol/L Tris(pH 7.4),yet each substrate induces similar high-spin heme content.For palmitate in low phosphate buffer concentrations,the rate constant of the first electron transfer is much larger than kcat.The results suggest that phosphate has a specific effect in promoting the first electron transfer step,and that P450_(BM3) could modulate Bacillus membrane morphology and fluidity via palmitate oxidation in response to the external phosphate concentration.
文摘Both China and Indonesia are influential maritime powers in the Asia-Pacific region.Strengthening practical maritime cooperation is highly significant to both sides as an important component of comprehensive strategic cooperation.Maritime cooperation has become a prominent part of the“five pillar”cooperation framework between the two countries alongside political,economic,people-to-people exchange,and security,playing a positive role in elevating the China-Indonesia comprehensive strategic partnership to a higher level.
文摘The year 2025 marks the 50th anniversary of the establishment of diplomatic relations between China and Thailand,as well as the“Golden Jubilee of Sino-Thai Friendship”.Over the past half-century,the scale and scope of economic and trade cooperation between China and Thailand have dramatically expanded.Both nations have strengthened their bilateral economic ties,which have increasingly strengthened their interdependence and.complementarity,presenting a broad prospect of mutual benefit and win-win cooperation.
文摘Since the resumption of diplomatic relations between China and Indonesia in the 1990s,the economic and trade cooperation between the two countries has developed rapidly and continuously.Since 2013,the scale of trade between the two countries has expanded year on year,and investment has broadened from traditional agriculture and industry to the digital economy and financial insurance,which has effectively promoted industrial development in both countries.More infrastructure cooperation has significantly improved the development environment in Indonesia,producing tangible benefits for the local people.Different types of special economic zones have facilitated breakthrough development for Indonesian industries while creating employment opportunities for local residents and driving local economic development.
文摘On September 1st,the 18th Chi na-LAC Business Summit Promotion Conference opened in Beijing.Chinese and foreign vips gathered to prepare for the 18th China LAC Business Summit,planned for Zhengzhou,Henan,from November 3rd to 4th.
