The development of human settlements(HS)in coastal cities is an integral component and a vital pathway toward building a strong marine power.It is also an essential requirement for achieving the coordinated developmen...The development of human settlements(HS)in coastal cities is an integral component and a vital pathway toward building a strong marine power.It is also an essential requirement for achieving the coordinated development of HS systems in these cities.In this study,we constructed an indicator system to analyze the coupling coordination degree(CCD)of HS systems in coastal cities in the Bohai Rim region of China(CCBRR).This study is based on five systems and employs methods such as the entropy weight method,CCD model,spatial trend surface analysis,and geographic detector to examine comprehensively the spatial and temporal patterns of CCD in 17 CCBRR during the period 2011–2022,as well as to explore their influencing factors.The findings are as follows:(1)Temporally,the CCD is high and exhibits a slow increasing trend,with distinct stage characteristics.(2)Spatially,the distribution of CCD reveals a“one core,many strengths”structural pattern.(3)Moreover,socioeconomic factors are the dominant force driving the CCD of the internal HS systems in the CCBRR.(4)Finally,we constructed a coupling coordination driving mechanism for HS in the CCBRR with the aim of providing scientific references and path choices for the high-quality and coordinated development of the CCBRR along with the implementation of the new quality productive forces regionalization.展开更多
A three-dimensional coordination polymer [Mn2（μ1.3-N3）4（μ-PP）2]n （PP = 3-（pyrazin-2-yloxy）-pyridine） has been synthesized with 3-（pyrazin-2-yloxy）-pyridine and azide anion as mixed bridge ligand, and its c...A three-dimensional coordination polymer [Mn2（μ1.3-N3）4（μ-PP）2]n （PP = 3-（pyrazin-2-yloxy）-pyridine） has been synthesized with 3-（pyrazin-2-yloxy）-pyridine and azide anion as mixed bridge ligand, and its crystal structure was determined by X-ray crystallography. The crystal data： triclinic system, space group P1, with a = 6.794（4）, b = 9.885（6）, c = 9.947（6） A, α = 64.170（6）, β= 84.190（8）, γ= 85.319（8）°, V = 597.7（6）A^3, Z = 1, C18H14Mn2N18O2, Mr = 624.35, Dc = 1.735 g/cm^3, F（000） = 314 and μ = 1.117 mm^-1. In the crystal, the azide anion acts as a bridge ligand and makes adjacent Mn（Ⅱ） ions connect into a two-dimensional sheet on the ab plane, then 3-（pyrazin-2-yloxy）-pyridine serves as a bidentate bridge ligand to connect neighboring sheets along展开更多
To objectively obtain the three-dimensional coordinates of the projectile fuze proximity explosion when projectile intersects the head of missile target, we propose a dynamic seven photoelectric detection screen test ...To objectively obtain the three-dimensional coordinates of the projectile fuze proximity explosion when projectile intersects the head of missile target, we propose a dynamic seven photoelectric detection screen test method, which is made up of six plane detection screens and a flash photoelectric dynamic detection screen. The three-dimensional coordinates calculation model of the projectile proximity explosion position based on seven plane detection screens with dynamic characteristics is established.According to the relation of the dynamic seven photoelectric detection screen planes and the time values,the analytical function of the projectile proximity explosion position parameters under non-linear motion is derived. The projectile signal filtering method based on discrete wavelet transform is explored in this work. Additionally, the projectile signal recognition algorithm using an improved particle swarm is proposed. Based on the characteristics of the time duration and the signal peak error for the projectile passing through the detection screen, the signals attribution of the same projectile passing through six detection screens are analyzed for obtaining precise time values of the same projectile passing through the detection screens. On the basis of the projectile fuze proximity explosion test, the linear motion model and the proposed non-linear motion model are used to calculate and compare the same group of projectiles proximity explosion position parameters. The comparison of test results verifies that the proposed test method and calculation model in this work accurately obtain the actual projectile proximity explosion position parameters.展开更多
Developing nonprecious electrocatalysts with bifunctional performances for oxygen reduction(ORR)and evolution reactions(OER)remains a crucial challenge in rechargeable Zn-air batteries(RZABs).In this study,we report t...Developing nonprecious electrocatalysts with bifunctional performances for oxygen reduction(ORR)and evolution reactions(OER)remains a crucial challenge in rechargeable Zn-air batteries(RZABs).In this study,we report the synthesis of a three-dimensional(3D)porous N,P-doped carbon-wrapped cobalt phosphide composite(Co2P@3DNPC)via direct calcination of a novel organic/inorganic porous coordi-nation polymer by an in-situ phosphating strategy.DFT calculations demonstrate the intricate interac-tions occurring during the PEI-directed grinding self-assembly process among Co^(2+),phytic acid(PA),and polyethylenimine(PEI).Specifically,Co^(2+)ions initially adsorb onto PEI molecules before integrating with PA to form a 3D coordination polymer matrix.As-fabricated Co2P@3DNPC composite exhibits impressive ORR/OER bifunctional performances,with a half-wave potential of 0.78 V and an overpotential of 1.71 V,respectively.Its bifunctional activities enable a power density of 148.5 mW cm^(-2)in rechargeable ZABs,with remarkable stability(>480 h)during a discharge-charge cycle.The interconnected porous structure and embedded Co2P nanoparticles optimize the electrode-electrolyte interfacial contact,boosting energy density and cycle life of as-assembled ZABs.This innovative approach paves the way for efficient,cost-effective production of bifunctional electrocatalysts for RZABs.展开更多
Research on pipe dynamics primarily focuses on in-plane vibration.However,pipes simultaneously experience in-plane and out-of-plane vibrations.Therefore,a three-dimensional dynamic model using the absolute nodal coord...Research on pipe dynamics primarily focuses on in-plane vibration.However,pipes simultaneously experience in-plane and out-of-plane vibrations.Therefore,a three-dimensional dynamic model using the absolute nodal coordinate formulation(ANCF)method is established and the dynamic characteristics of a planar L-shaped pipe are analyzed.Firstly,the dynamic equations of the pipe element are derived,and then the overall equations of the pipe model are composed by matrix assembly.By solving equations,it is found that static deformation caused by fluid velocity occurs in the plane,with larger deformations at higher fluid velocities.Additionally,the study observes coupling between different modes and variations in modal shapes.Variations in arc segment structural parameters result in non-uniform changes in natural frequencies,with out-of-plane vibration presenting even more complexity,and the results are verified by ANSYS simulation.Subsequently,a comparison between experimental and theoretical results is conducted across three sets of structural parameters,the consistency between these results validates the engineering significance of the theoretical model.展开更多
Coordinated contraction of skeletal muscles relies on selective connections between the muscles and multiple classes of the spinal motoneuro ns.Howeve r,current research on the spatial location of the spinal motoneuro...Coordinated contraction of skeletal muscles relies on selective connections between the muscles and multiple classes of the spinal motoneuro ns.Howeve r,current research on the spatial location of the spinal motoneurons innervating differe nt muscles is limited.In this study,we investigated the spatial distribution and relative position of different motoneurons that control the deep muscles of the mouse hindlimbs,which were innervated by the obturator nerve,femoral nerve,inferior gluteal nerve,deep pe roneal nerve,and tibial nerve.Locations were visualized by combining a multiplex retrograde tracking technique compatible with three-dimensional imaging of solvent-cleared o rgans(3DISCO)and 3-D imaging technology based on lightsheet fluorescence microscopy(LSFM).Additionally,we propose the hypothesis that"messenger zones"exist as interlaced areas between the motoneuron pools that dominate the synergistic or antagonist muscle groups.We hypothesize that these interlaced neurons may participate in muscle coordination as messenger neurons.Analysis revealed the precise mutual positional relationships among the many motoneurons that innervate different deep muscles of the mouse.Not only do these findings update and supplement our knowledge regarding the overall spatial layout of spinal motoneurons that control mouse limb muscles,but they also provide insights into the mechanisms through which muscle activity is coordinated and the architecture of motor circuits.展开更多
In this work,based on the role of pre-ionization of the non-uniform electric field and its effect of reducing the collisional ionization coefficient,a diffuse dielectric barrier discharge plasma is formed in the open ...In this work,based on the role of pre-ionization of the non-uniform electric field and its effect of reducing the collisional ionization coefficient,a diffuse dielectric barrier discharge plasma is formed in the open space outside the electrode structure at a lower voltage by constructing a three-dimensional non-uniform spatial electric field using a contact electrode structure.The air purification study is also carried out.Firstly,a contact electrode structure is constructed using a three-dimensional wire electrode.The distribution characteristics of the spatial electric field formed by this electrode structure are analyzed,and the effects of the non-uniform electric field and the different angles of the vertical wire on the generation of three-dimensional spatial diffuse discharge are investigated.Secondly,the copper foam contact electrode structure is constructed using copper foam material,and the effects of different mesh sizes on the electric field distribution are analyzed.The results show that as the mesh size of the copper foam becomes larger,a strong electric field region exists not only on the surface of the insulating layer,but also on the surface of the vertical wires inside the copper foam,i.e.,the strong electric field region shows a three-dimensional distribution.Besides,as the mesh size increases,the area of the vertical strong electric field also increases.However,the electric field strength on the surface of the insulating layer gradually decreases.Therefore,the appropriate mesh size can effectively increase the discharge area,which is conducive to improving the air purification efficiency.Finally,a highly permeable stacked electrode structure of multilayer wire-copper foam is designed.In combination with an ozone treatment catalyst,an air purification device is fabricated,and the air purification experiment is carried out.展开更多
For forward-looking array synthetic aperture radar(FASAR),the scattering intensity of ground scatterers fluctuates greatly since there are kinds of vegetations and topography on the surface of the ground,and thus the ...For forward-looking array synthetic aperture radar(FASAR),the scattering intensity of ground scatterers fluctuates greatly since there are kinds of vegetations and topography on the surface of the ground,and thus the signal-to-noise ratio(SNR)of its echo signals corresponding to different vegetations and topography also varies obviously.Owing to the reason known to all,the performance of the sparse reconstruction of compressed sensing(CS)becomes worse in the case of lower SNR,and the quality of the sparse three-dimensional imaging for FASAR would be affected significantly in the practical application.In this paper,the spatial continuity of the ground scatterers is introduced to the sparse recovery algorithm of CS in the threedimensional imaging for FASAR,in which the weighted least square method of the cubic interpolation is used to filter out the bad and isolated scatterer.The simulation results show that the proposed method can realize the sparse three-dimensional imaging of FASAR more effectively in the case of low SNR.展开更多
From the review of development history of indoor design in China, we can see that it develops rapidly from sprout to expansion, and has large professional scale. It goes through ignorance, misconception and comprehens...From the review of development history of indoor design in China, we can see that it develops rapidly from sprout to expansion, and has large professional scale. It goes through ignorance, misconception and comprehensive understanding. And it has developed into a perfect and independent composite subject. From the perspective of interior design continuing architectural design in time-space dimension, the paper focuses on observing the application analysis of coordinated interior design, which not only provides reference for interior design in China, but also improves the interior design in China.展开更多
In this paper, the coordination of spatial-temporal discrets of FEM and direct integral method is investigates.By analyzing the numespatial-temporal discrete,the principle of balancing the principle of balancing the...In this paper, the coordination of spatial-temporal discrets of FEM and direct integral method is investigates.By analyzing the numespatial-temporal discrete,the principle of balancing the principle of balancing the energy error induced by spatialdiscrete and the energy error induced by temporal discrete is presented, and the prioriprocess and adaptive method for the coordination of spatial discerand temporal discrete is obtained.展开更多
An integration processing system of three-dimensional laser scanning information visualization in goaf was developed. It is provided with multiple functions, such as laser scanning information management for goaf, clo...An integration processing system of three-dimensional laser scanning information visualization in goaf was developed. It is provided with multiple functions, such as laser scanning information management for goaf, cloud data de-noising optimization, construction, display and operation of three-dimensional model, model editing, profile generation, calculation of goaf volume and roof area, Boolean calculation among models and interaction with the third party soft ware. Concerning this system with a concise interface, plentiful data input/output interfaces, it is featured with high integration, simple and convenient operations of applications. According to practice, in addition to being well-adapted, this system is favorably reliable and stable.展开更多
This paper presents the cooperative strategies for salvo attack of multiple missiles based on the classical proportional navigation（PN） algorithm.The three-dimensional（3-D） guidance laws are developed in a quite s...This paper presents the cooperative strategies for salvo attack of multiple missiles based on the classical proportional navigation（PN） algorithm.The three-dimensional（3-D） guidance laws are developed in a quite simple formulation that consists of a PN component for target capture and a coordination component for simultaneous arrival.The centralized algorithms come into effect when the global information of time-to-go estimation is obtained, whereas the decentralized algorithms have better performance when each missile can only collect information from neighbors.Numerical simulations demonstrate that the proposed coordination algorithms are feasible to perform the cooperative engagement of multiple missiles against both stationary and maneuvering targets.The effectiveness of the 3-D guidance laws is also discussed.展开更多
Three types of spatial function zoning is an effective measure for regional environmental protection and orderly development.For ecological and economic coordinated development, spatial function zones should be divide...Three types of spatial function zoning is an effective measure for regional environmental protection and orderly development.For ecological and economic coordinated development, spatial function zones should be divided scientifically to clear its direction of development and protection. Therefore, based on ecological constraints, a beneficial discussion would be about the key ecological function areas adopting the concept of ecological protection restriction and supporting socioeconomic development for spatial function zoning. In this paper, the researchers, taking Tacheng Basin, Xinjiang of China as an example, choose township as basic research unit and set up an evaluation index system from three aspects, namely, ecological protection suitability, agricultural production suitability, and urban development suitability, which are analyzed by using spatial analysis functions and exclusive matrix method. The results showed that: 1) This paper formed a set of multilevel evaluation index systems for three types of spatial function zoning of the key ecological function areas based on a novel perspective by scientifically dividing Tacheng Basin into ecological space, agricultural space, and urban space,which realized the integration and scientific orientation for spatial function at the township scale. 2) Under the guidance of three types of spatial pattern, the functional orientation and suggestions of development and protection was clearly defined for ecological protection zones,ecological economic zones, agricultural production zones, and urban development zones. 3) A new idea of space governance is provided to promote the coordinated and sustainable development between ecology and economy, which can break the traditional mode of thinking about regional economic development, and offers a scientific basis and reference for macro decision-making.展开更多
Suitable spatial morphology of cultivated land is a basic requirement for sustaining agricultural economic development in mountainous areas.Coordinated development efficiency of cultivated land spatial morphology and ...Suitable spatial morphology of cultivated land is a basic requirement for sustaining agricultural economic development in mountainous areas.Coordinated development efficiency of cultivated land spatial morphology and agricultural economy(CECA)is of great practical significance to measure the efficiency of cultivated land use,and thereby promote regional rural revitalization.However,few studies to date have focused on coordinated development efficiency between cultivated land use and agricultural economy in mountainous areas from the perspective of cultivated land spatial morphology.Thus,the present study explores CECA with this focus using the data envelopment analysis method,and analyzes the key influencing factors via a geographical detector model in 16 counties in western Hubei province.The results show the following:(1)CECA exhibits significant spatial heterogeneity that is high in the south of the study area and low in the north;(2)scale efficiency is the primary limiting factor for CECA;(3)the insufficient output of cultivated land use mainly restricts CECA in the south of the study area,while individual county in the north suffered from input redundancy and insufficient output;and(4)population density in the southern region has the most significant effect on CECA,and gross domestic product has the greatest impact in the northern region.The results contribute to the derivation of specific measures by which to promote cultivated land use efficiency and sustainable development of the social economy.展开更多
The 2D limit equilibrium method is widely used for slope stability analysis.However,with the advancement of dump engineering,composite slopes often exhibit significant 3D mechanical effects.Consequently,it is of signi...The 2D limit equilibrium method is widely used for slope stability analysis.However,with the advancement of dump engineering,composite slopes often exhibit significant 3D mechanical effects.Consequently,it is of significant importance to develop an effective 3D stability calculation method for composite slopes to enhance the design and stability control of open-pit slope engineering.Using the composite slope formed by the mining stope and inner dump in Baiyinhua No.1 and No.2 open-pit coal mine as a case study,this research investigates the failure mode of composite slopes and establishes spatial shape equations for the sliding mass.By integrating the shear resistance and sliding force of each row of microstrip columns onto the bottom surface of the strip corresponding to the main sliding surface,a novel 2D equivalent physical and mechanical parameters analysis method for the strips on the main sliding surface of 3D sliding masses is proposed.Subsequently,a comprehensive 3D stability calculation method for composite slopes is developed,and the quantitative relationship between the coordinated development distance and its 3D stability coefficients is examined.The analysis reveals that the failure mode of the composite slope is characterized by cutting-bedding sliding,with the arc serving as the side interface and the weak layer as the bottom interface,while the destabilization mechanism primarily involves shear failure.The spatial form equation of the sliding mass comprises an ellipsoid and weak plane equation.The analysis revealed that when the coordinated development distance is 1500 m,the error rate between the 3D stability calculation result and the 2D stability calculation result of the composite slope is less than 8%,thereby verifying the proposed analytical method of equivalent physical and mechanical parameters and the 3D stability calculation method for composite slopes.Furthermore,the3D stability coefficient of the composite slope exhibits an exponential correlation with the coordinated development distance,with the coefficient gradually decreasing as the coordinated development distance increases.These findings provide a theoretical guideline for designing similar slope shape parameters and conducting stability analysis.展开更多
The characteristics of three-dimensional （3-D） tidal current in the Oujiang Estuary are investigated according to in situ observations. The Oujiang Estuary has features of irregular coastline, complex topography, ma...The characteristics of three-dimensional （3-D） tidal current in the Oujiang Estuary are investigated according to in situ observations. The Oujiang Estuary has features of irregular coastline, complex topography, many islands, moveable boundary, and submerged dyke, therefore, σ 3-D numerical model oil an unstructured triangular grid has been degeloped. The σ coordinate transforination, the moveable boundary and submerged dyke treatment techniques were employed in the model so it is suitable for the tidal simulations in the Oujing Estuary with submerged dyke and moveable boundary problems. The model is evaluated with the in situ data, and the results show that the calculated water elevations at 19 stations and currents at 19 profiler stations are in good agreement with measured data both in magnitude and phase. This numerical model is applied to the 3-D tidal circulation simulations of experiments in stopping flow transport through the South Branch of the Oujiang Estuary, and the feasibility to cutoff the flow in the South Branch of the Oujiang Estuary is demonstrated by numerical simulation experiments. The developed numerical model simulated the 3-D tidal current circulations in complicated coastal and estuarine waters very well.展开更多
To correct a lower limb deformity, orthopedic surgeons must have an exact understanding of the deformity. In general, preoperative planning is carried out using anterior-posterior (AP) and lateral radiographs. However...To correct a lower limb deformity, orthopedic surgeons must have an exact understanding of the deformity. In general, preoperative planning is carried out using anterior-posterior (AP) and lateral radiographs. However, for severe cases with a combination of angular and rotational deformities of the lower limb, obtaining true AP and lateral radiographs is difficult and accurate calculation of the rotational deformity from radiographs is impossible. In this report, we propose to focus on preoperative assessment using three-dimensional (3D) reconstruction images of computed tomography (CT) scans for severe lower limb deformity in a patient with bilateral fibular hemimelia type II according to the Achterman- Kalamchi classification. She underwent bifocal deformity corrections of the bilateral tibiae using Taylor spatial frames in combination with the Ilizarov external fixator. Complete bony union was achieved, without angular deformity or limb length discrepancy.展开更多
A new three-dimensional Zn（II） coordination polymer, namely [Zn4（bpydb）3（tz）2（H2O）2]n（1）, has been synthesized by the self-assembly reactions of Zn（NO3）2·6H2O, bpydb H2, Htz and DMF. Single-crystal X-...A new three-dimensional Zn（II） coordination polymer, namely [Zn4（bpydb）3（tz）2（H2O）2]n（1）, has been synthesized by the self-assembly reactions of Zn（NO3）2·6H2O, bpydb H2, Htz and DMF. Single-crystal X-ray structural analysis reveals that compound 1 features a three-dimensional framework structure and is the first example of Zn-containing coordination polymers based on two kinds of ligands bpydb H2 and Htz. It crystallizes in triclinic, space group P1 with a = 14.9953（12）, b = 17.5335（17）, c = 20.2381（11）A, α = 115.225（7）, β = 92.329（5）, γ = 105.606（8）o, V = 4561.9（7） A^3, Z = 2, F（000） = 1644, Dc = 1.177 Mg/m^3, Mr = 1616.76 and μ = 1.098 mm^-1. The antitumor activities of compound 1 and its corresponding organic ligands（bpydb H2 and Htz） were investigated for inhibiting human osteosarcoma cells（MG-63 and U-2 OS） growth by MTT assay. It was found that compared with the two ligands, compound 1 exerted rather potent activities against all of these cell lines.展开更多
Accurate and sensitive determination of uric acid(UA)is critical,as abnormal UA concentrations are associated with various pathologies.Electrochemical sensing is an effective method for the detection of UA concentrati...Accurate and sensitive determination of uric acid(UA)is critical,as abnormal UA concentrations are associated with various pathologies.Electrochemical sensing is an effective method for the detection of UA concentrations.The electrochemical behavior of UA sensors is fundamentally governed by the electronic configurations of catalytically active sites,where enhanced site activity significantly improves overall performance.In this work,biocompatible g-C_(3)N_(4)is selectively doped with cobalt to generate UA-specific surface centers.These are synergistically integrated with highly conductive Ti_(3)CNto optimize charge transport efficiency.The oxygen-terminated surface of Ti_(3)CNforms strong chemical bonds with the Co-doped sites,enabling precise modulation of their electronic structure.DFT calculations reveal substantial electron transfer from cobalt atoms to surface oxygen groups,which shifts the Co d-band center,reduces the desorption barrier for UA oxidation intermediates,and accelerates the catalytic process.The resulting Co-CN/Ti_(3)CN-modified GCE demonstrates a broad linear detection range and ultralow detection limit.This study establishes an atomic-scale design strategy for electrochemical sensors capable of trace-level UA detection,offering a promising platform for clinical diagnostics and biomedical monitoring.展开更多
The construction of a new type of urbanization is a necessary path for the development of modern cities,and a powerful support for coordinating the balanced development of urban and rural areas and promoting high-qual...The construction of a new type of urbanization is a necessary path for the development of modern cities,and a powerful support for coordinating the balanced development of urban and rural areas and promoting high-quality agricultural development.Based on the panel data of 30 provinces in China from 2004 to 2018,the article constructs a new urbanization and agricultural high-quality development evaluation system;then using the coupling coordination degree model and the spatial correlation analysis method,the paper empirically tests the coupling coordination of the two systems degree and its spatial relevance.The results of the study show that the average level of coupling and coordination between new urbanization and high-quality agricultural development in the period under study is at a barely coordinated level,with the highest level being moderately coordinated.There are significant inter-regional differences,with a higher level of coupling and coordination in the eastern regions and more room for improvement in the central and western regions.At this stage,the trend of"club convergence"is remarkable,with highhigh agglomeration and low-low agglomeration coexisting,and the polarization is serious.Therefore,comprehensively promoting the rural revitalization strategy,adhering to the integrated development of urban and rural areas,and enhancing inter-regional collaborative governance are powerful measures to promote the joint progress of new urbanization and high-quality agricultural development.展开更多
基金National Natural Science Foundation of China,No.42201221,No.42471246Liaoning Province Natural Science Foundation Project,No.2023-MS-254+1 种基金Liaoning Province Social Science Planning Fund Project,No.L22CJY016Dalian Federation of Social Sciences,No.2022dlskzd037。
文摘The development of human settlements(HS)in coastal cities is an integral component and a vital pathway toward building a strong marine power.It is also an essential requirement for achieving the coordinated development of HS systems in these cities.In this study,we constructed an indicator system to analyze the coupling coordination degree(CCD)of HS systems in coastal cities in the Bohai Rim region of China(CCBRR).This study is based on five systems and employs methods such as the entropy weight method,CCD model,spatial trend surface analysis,and geographic detector to examine comprehensively the spatial and temporal patterns of CCD in 17 CCBRR during the period 2011–2022,as well as to explore their influencing factors.The findings are as follows:(1)Temporally,the CCD is high and exhibits a slow increasing trend,with distinct stage characteristics.(2)Spatially,the distribution of CCD reveals a“one core,many strengths”structural pattern.(3)Moreover,socioeconomic factors are the dominant force driving the CCD of the internal HS systems in the CCBRR.(4)Finally,we constructed a coupling coordination driving mechanism for HS in the CCBRR with the aim of providing scientific references and path choices for the high-quality and coordinated development of the CCBRR along with the implementation of the new quality productive forces regionalization.
基金Supported by the National Natural Science Foundation of China (No. 20271043)Natural Science Foundation of Shandong Province (Y2007B26)
文摘A three-dimensional coordination polymer [Mn2（μ1.3-N3）4（μ-PP）2]n （PP = 3-（pyrazin-2-yloxy）-pyridine） has been synthesized with 3-（pyrazin-2-yloxy）-pyridine and azide anion as mixed bridge ligand, and its crystal structure was determined by X-ray crystallography. The crystal data： triclinic system, space group P1, with a = 6.794（4）, b = 9.885（6）, c = 9.947（6） A, α = 64.170（6）, β= 84.190（8）, γ= 85.319（8）°, V = 597.7（6）A^3, Z = 1, C18H14Mn2N18O2, Mr = 624.35, Dc = 1.735 g/cm^3, F（000） = 314 and μ = 1.117 mm^-1. In the crystal, the azide anion acts as a bridge ligand and makes adjacent Mn（Ⅱ） ions connect into a two-dimensional sheet on the ab plane, then 3-（pyrazin-2-yloxy）-pyridine serves as a bidentate bridge ligand to connect neighboring sheets along
基金supported by Project of the National Natural Science Foundation of China (No.62073256, 61773305)the Key Science and Technology Program of Shaanxi Province (No.2020GY-125)Xi’an Science and Technology Innovation talent service enterprise project (No.2020KJRC0041)。
文摘To objectively obtain the three-dimensional coordinates of the projectile fuze proximity explosion when projectile intersects the head of missile target, we propose a dynamic seven photoelectric detection screen test method, which is made up of six plane detection screens and a flash photoelectric dynamic detection screen. The three-dimensional coordinates calculation model of the projectile proximity explosion position based on seven plane detection screens with dynamic characteristics is established.According to the relation of the dynamic seven photoelectric detection screen planes and the time values,the analytical function of the projectile proximity explosion position parameters under non-linear motion is derived. The projectile signal filtering method based on discrete wavelet transform is explored in this work. Additionally, the projectile signal recognition algorithm using an improved particle swarm is proposed. Based on the characteristics of the time duration and the signal peak error for the projectile passing through the detection screen, the signals attribution of the same projectile passing through six detection screens are analyzed for obtaining precise time values of the same projectile passing through the detection screens. On the basis of the projectile fuze proximity explosion test, the linear motion model and the proposed non-linear motion model are used to calculate and compare the same group of projectiles proximity explosion position parameters. The comparison of test results verifies that the proposed test method and calculation model in this work accurately obtain the actual projectile proximity explosion position parameters.
基金supported by the Research Project of the Hubei Provincial Department of Education(Grant No.Q20232503)the Hubei Provincial Natural Science Foundation and Huangshi of China(No.2022CFD039)+8 种基金the National Natural Science Foundation of China(Nos.22075072 and 52301272)the Program for Innovative Teams of Outstanding Young and Middle-aged Researchers in the Higher Education Institutions of Hubei Province(No.T2021010)the Natural Science Foundation of Hubei Province(No.2023AFB1010)the Natural Science Foundation of Zhejiang Province(No.LQ23E020002)the Wenzhou Key Scientific and Technological Innovation Research Project(No.ZG2023053)the Wenzhou Natural Science Foundation(No.G20220019)the Cooperation between industry and education project of Ministry of Education(No.220601318235513)the Wenzhou Science and Technology Association Serves Scientific and Technological Innovation Projects(KJFW0201)The State Key Laboratory funding of Disaster Prevention&Mitigation of Explosion&Impact(No.LGD-SKL-202203).
文摘Developing nonprecious electrocatalysts with bifunctional performances for oxygen reduction(ORR)and evolution reactions(OER)remains a crucial challenge in rechargeable Zn-air batteries(RZABs).In this study,we report the synthesis of a three-dimensional(3D)porous N,P-doped carbon-wrapped cobalt phosphide composite(Co2P@3DNPC)via direct calcination of a novel organic/inorganic porous coordi-nation polymer by an in-situ phosphating strategy.DFT calculations demonstrate the intricate interac-tions occurring during the PEI-directed grinding self-assembly process among Co^(2+),phytic acid(PA),and polyethylenimine(PEI).Specifically,Co^(2+)ions initially adsorb onto PEI molecules before integrating with PA to form a 3D coordination polymer matrix.As-fabricated Co2P@3DNPC composite exhibits impressive ORR/OER bifunctional performances,with a half-wave potential of 0.78 V and an overpotential of 1.71 V,respectively.Its bifunctional activities enable a power density of 148.5 mW cm^(-2)in rechargeable ZABs,with remarkable stability(>480 h)during a discharge-charge cycle.The interconnected porous structure and embedded Co2P nanoparticles optimize the electrode-electrolyte interfacial contact,boosting energy density and cycle life of as-assembled ZABs.This innovative approach paves the way for efficient,cost-effective production of bifunctional electrocatalysts for RZABs.
基金supported by the China National Funds for Distinguished Young Scholars(Grant No.12025204)the project of the National Natural Science Foundation of China(Grant No.12072181)the YEQISUN Joint Funds of the National Science Foundation of China(Grant No.U2341231).
文摘Research on pipe dynamics primarily focuses on in-plane vibration.However,pipes simultaneously experience in-plane and out-of-plane vibrations.Therefore,a three-dimensional dynamic model using the absolute nodal coordinate formulation(ANCF)method is established and the dynamic characteristics of a planar L-shaped pipe are analyzed.Firstly,the dynamic equations of the pipe element are derived,and then the overall equations of the pipe model are composed by matrix assembly.By solving equations,it is found that static deformation caused by fluid velocity occurs in the plane,with larger deformations at higher fluid velocities.Additionally,the study observes coupling between different modes and variations in modal shapes.Variations in arc segment structural parameters result in non-uniform changes in natural frequencies,with out-of-plane vibration presenting even more complexity,and the results are verified by ANSYS simulation.Subsequently,a comparison between experimental and theoretical results is conducted across three sets of structural parameters,the consistency between these results validates the engineering significance of the theoretical model.
基金supported by the Chinese National General Program of the National Natural Science Foundation of China,No.82072162(to XY)。
文摘Coordinated contraction of skeletal muscles relies on selective connections between the muscles and multiple classes of the spinal motoneuro ns.Howeve r,current research on the spatial location of the spinal motoneurons innervating differe nt muscles is limited.In this study,we investigated the spatial distribution and relative position of different motoneurons that control the deep muscles of the mouse hindlimbs,which were innervated by the obturator nerve,femoral nerve,inferior gluteal nerve,deep pe roneal nerve,and tibial nerve.Locations were visualized by combining a multiplex retrograde tracking technique compatible with three-dimensional imaging of solvent-cleared o rgans(3DISCO)and 3-D imaging technology based on lightsheet fluorescence microscopy(LSFM).Additionally,we propose the hypothesis that"messenger zones"exist as interlaced areas between the motoneuron pools that dominate the synergistic or antagonist muscle groups.We hypothesize that these interlaced neurons may participate in muscle coordination as messenger neurons.Analysis revealed the precise mutual positional relationships among the many motoneurons that innervate different deep muscles of the mouse.Not only do these findings update and supplement our knowledge regarding the overall spatial layout of spinal motoneurons that control mouse limb muscles,but they also provide insights into the mechanisms through which muscle activity is coordinated and the architecture of motor circuits.
基金supported by the Fundamental Research Funds for the Central Universities(No.2022YJS094)。
文摘In this work,based on the role of pre-ionization of the non-uniform electric field and its effect of reducing the collisional ionization coefficient,a diffuse dielectric barrier discharge plasma is formed in the open space outside the electrode structure at a lower voltage by constructing a three-dimensional non-uniform spatial electric field using a contact electrode structure.The air purification study is also carried out.Firstly,a contact electrode structure is constructed using a three-dimensional wire electrode.The distribution characteristics of the spatial electric field formed by this electrode structure are analyzed,and the effects of the non-uniform electric field and the different angles of the vertical wire on the generation of three-dimensional spatial diffuse discharge are investigated.Secondly,the copper foam contact electrode structure is constructed using copper foam material,and the effects of different mesh sizes on the electric field distribution are analyzed.The results show that as the mesh size of the copper foam becomes larger,a strong electric field region exists not only on the surface of the insulating layer,but also on the surface of the vertical wires inside the copper foam,i.e.,the strong electric field region shows a three-dimensional distribution.Besides,as the mesh size increases,the area of the vertical strong electric field also increases.However,the electric field strength on the surface of the insulating layer gradually decreases.Therefore,the appropriate mesh size can effectively increase the discharge area,which is conducive to improving the air purification efficiency.Finally,a highly permeable stacked electrode structure of multilayer wire-copper foam is designed.In combination with an ozone treatment catalyst,an air purification device is fabricated,and the air purification experiment is carried out.
基金supported by the National Natural Science Foundation of China(61640006)the Natural Science Foundation of Shannxi Province,China(2019JM-386).
文摘For forward-looking array synthetic aperture radar(FASAR),the scattering intensity of ground scatterers fluctuates greatly since there are kinds of vegetations and topography on the surface of the ground,and thus the signal-to-noise ratio(SNR)of its echo signals corresponding to different vegetations and topography also varies obviously.Owing to the reason known to all,the performance of the sparse reconstruction of compressed sensing(CS)becomes worse in the case of lower SNR,and the quality of the sparse three-dimensional imaging for FASAR would be affected significantly in the practical application.In this paper,the spatial continuity of the ground scatterers is introduced to the sparse recovery algorithm of CS in the threedimensional imaging for FASAR,in which the weighted least square method of the cubic interpolation is used to filter out the bad and isolated scatterer.The simulation results show that the proposed method can realize the sparse three-dimensional imaging of FASAR more effectively in the case of low SNR.
文摘From the review of development history of indoor design in China, we can see that it develops rapidly from sprout to expansion, and has large professional scale. It goes through ignorance, misconception and comprehensive understanding. And it has developed into a perfect and independent composite subject. From the perspective of interior design continuing architectural design in time-space dimension, the paper focuses on observing the application analysis of coordinated interior design, which not only provides reference for interior design in China, but also improves the interior design in China.
文摘In this paper, the coordination of spatial-temporal discrets of FEM and direct integral method is investigates.By analyzing the numespatial-temporal discrete,the principle of balancing the principle of balancing the energy error induced by spatialdiscrete and the energy error induced by temporal discrete is presented, and the prioriprocess and adaptive method for the coordination of spatial discerand temporal discrete is obtained.
基金Project(51274250)supported by the National Natural Science Foundation of ChinaProject(2012BAK09B02-05)supported by the National Key Technology R&D Program during the 12th Five-year Plan of China
文摘An integration processing system of three-dimensional laser scanning information visualization in goaf was developed. It is provided with multiple functions, such as laser scanning information management for goaf, cloud data de-noising optimization, construction, display and operation of three-dimensional model, model editing, profile generation, calculation of goaf volume and roof area, Boolean calculation among models and interaction with the third party soft ware. Concerning this system with a concise interface, plentiful data input/output interfaces, it is featured with high integration, simple and convenient operations of applications. According to practice, in addition to being well-adapted, this system is favorably reliable and stable.
基金supported by the National Natural Science Foundation of China (Nos.61273349, 61203223)
文摘This paper presents the cooperative strategies for salvo attack of multiple missiles based on the classical proportional navigation（PN） algorithm.The three-dimensional（3-D） guidance laws are developed in a quite simple formulation that consists of a PN component for target capture and a coordination component for simultaneous arrival.The centralized algorithms come into effect when the global information of time-to-go estimation is obtained, whereas the decentralized algorithms have better performance when each missile can only collect information from neighbors.Numerical simulations demonstrate that the proposed coordination algorithms are feasible to perform the cooperative engagement of multiple missiles against both stationary and maneuvering targets.The effectiveness of the 3-D guidance laws is also discussed.
基金Under the auspices of Grant Program of Clean Development Mechanism Fund of China(CDMF)(No.2014092)Task 2 of Key Service Project 5 for the Characteristic Institute of Chinese Academy of Sciences(No.TSS-2015-014-FW-5-2)+2 种基金National Natural Science Foundation of China(No.41571159)The Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA20010301)Jiangsu Natural Science Foundation(No.BK20181105)
文摘Three types of spatial function zoning is an effective measure for regional environmental protection and orderly development.For ecological and economic coordinated development, spatial function zones should be divided scientifically to clear its direction of development and protection. Therefore, based on ecological constraints, a beneficial discussion would be about the key ecological function areas adopting the concept of ecological protection restriction and supporting socioeconomic development for spatial function zoning. In this paper, the researchers, taking Tacheng Basin, Xinjiang of China as an example, choose township as basic research unit and set up an evaluation index system from three aspects, namely, ecological protection suitability, agricultural production suitability, and urban development suitability, which are analyzed by using spatial analysis functions and exclusive matrix method. The results showed that: 1) This paper formed a set of multilevel evaluation index systems for three types of spatial function zoning of the key ecological function areas based on a novel perspective by scientifically dividing Tacheng Basin into ecological space, agricultural space, and urban space,which realized the integration and scientific orientation for spatial function at the township scale. 2) Under the guidance of three types of spatial pattern, the functional orientation and suggestions of development and protection was clearly defined for ecological protection zones,ecological economic zones, agricultural production zones, and urban development zones. 3) A new idea of space governance is provided to promote the coordinated and sustainable development between ecology and economy, which can break the traditional mode of thinking about regional economic development, and offers a scientific basis and reference for macro decision-making.
基金National Natural Science Foundation of China,No.71804168。
文摘Suitable spatial morphology of cultivated land is a basic requirement for sustaining agricultural economic development in mountainous areas.Coordinated development efficiency of cultivated land spatial morphology and agricultural economy(CECA)is of great practical significance to measure the efficiency of cultivated land use,and thereby promote regional rural revitalization.However,few studies to date have focused on coordinated development efficiency between cultivated land use and agricultural economy in mountainous areas from the perspective of cultivated land spatial morphology.Thus,the present study explores CECA with this focus using the data envelopment analysis method,and analyzes the key influencing factors via a geographical detector model in 16 counties in western Hubei province.The results show the following:(1)CECA exhibits significant spatial heterogeneity that is high in the south of the study area and low in the north;(2)scale efficiency is the primary limiting factor for CECA;(3)the insufficient output of cultivated land use mainly restricts CECA in the south of the study area,while individual county in the north suffered from input redundancy and insufficient output;and(4)population density in the southern region has the most significant effect on CECA,and gross domestic product has the greatest impact in the northern region.The results contribute to the derivation of specific measures by which to promote cultivated land use efficiency and sustainable development of the social economy.
基金supported by the National Natural Science Foundation of China (No.52374124)National Youth Science Foundation of China (No.52204135)+3 种基金Xing Liao Talent Plan (No.XLYC2202004)Young Elite Scientists Sponsorship Program by CAST (No.2023QNRC001)Liaoning Province International Science and Technology Cooperation Plan (No.2022JH2/1070004)Liaoning Natural Science Foundation Program (No.2022-BS-327)。
文摘The 2D limit equilibrium method is widely used for slope stability analysis.However,with the advancement of dump engineering,composite slopes often exhibit significant 3D mechanical effects.Consequently,it is of significant importance to develop an effective 3D stability calculation method for composite slopes to enhance the design and stability control of open-pit slope engineering.Using the composite slope formed by the mining stope and inner dump in Baiyinhua No.1 and No.2 open-pit coal mine as a case study,this research investigates the failure mode of composite slopes and establishes spatial shape equations for the sliding mass.By integrating the shear resistance and sliding force of each row of microstrip columns onto the bottom surface of the strip corresponding to the main sliding surface,a novel 2D equivalent physical and mechanical parameters analysis method for the strips on the main sliding surface of 3D sliding masses is proposed.Subsequently,a comprehensive 3D stability calculation method for composite slopes is developed,and the quantitative relationship between the coordinated development distance and its 3D stability coefficients is examined.The analysis reveals that the failure mode of the composite slope is characterized by cutting-bedding sliding,with the arc serving as the side interface and the weak layer as the bottom interface,while the destabilization mechanism primarily involves shear failure.The spatial form equation of the sliding mass comprises an ellipsoid and weak plane equation.The analysis revealed that when the coordinated development distance is 1500 m,the error rate between the 3D stability calculation result and the 2D stability calculation result of the composite slope is less than 8%,thereby verifying the proposed analytical method of equivalent physical and mechanical parameters and the 3D stability calculation method for composite slopes.Furthermore,the3D stability coefficient of the composite slope exhibits an exponential correlation with the coordinated development distance,with the coefficient gradually decreasing as the coordinated development distance increases.These findings provide a theoretical guideline for designing similar slope shape parameters and conducting stability analysis.
基金The Natural Science Foundation of Tianjin, China under contract No.08JCZDZT00200
文摘The characteristics of three-dimensional （3-D） tidal current in the Oujiang Estuary are investigated according to in situ observations. The Oujiang Estuary has features of irregular coastline, complex topography, many islands, moveable boundary, and submerged dyke, therefore, σ 3-D numerical model oil an unstructured triangular grid has been degeloped. The σ coordinate transforination, the moveable boundary and submerged dyke treatment techniques were employed in the model so it is suitable for the tidal simulations in the Oujing Estuary with submerged dyke and moveable boundary problems. The model is evaluated with the in situ data, and the results show that the calculated water elevations at 19 stations and currents at 19 profiler stations are in good agreement with measured data both in magnitude and phase. This numerical model is applied to the 3-D tidal circulation simulations of experiments in stopping flow transport through the South Branch of the Oujiang Estuary, and the feasibility to cutoff the flow in the South Branch of the Oujiang Estuary is demonstrated by numerical simulation experiments. The developed numerical model simulated the 3-D tidal current circulations in complicated coastal and estuarine waters very well.
文摘To correct a lower limb deformity, orthopedic surgeons must have an exact understanding of the deformity. In general, preoperative planning is carried out using anterior-posterior (AP) and lateral radiographs. However, for severe cases with a combination of angular and rotational deformities of the lower limb, obtaining true AP and lateral radiographs is difficult and accurate calculation of the rotational deformity from radiographs is impossible. In this report, we propose to focus on preoperative assessment using three-dimensional (3D) reconstruction images of computed tomography (CT) scans for severe lower limb deformity in a patient with bilateral fibular hemimelia type II according to the Achterman- Kalamchi classification. She underwent bifocal deformity corrections of the bilateral tibiae using Taylor spatial frames in combination with the Ilizarov external fixator. Complete bony union was achieved, without angular deformity or limb length discrepancy.
文摘A new three-dimensional Zn（II） coordination polymer, namely [Zn4（bpydb）3（tz）2（H2O）2]n（1）, has been synthesized by the self-assembly reactions of Zn（NO3）2·6H2O, bpydb H2, Htz and DMF. Single-crystal X-ray structural analysis reveals that compound 1 features a three-dimensional framework structure and is the first example of Zn-containing coordination polymers based on two kinds of ligands bpydb H2 and Htz. It crystallizes in triclinic, space group P1 with a = 14.9953（12）, b = 17.5335（17）, c = 20.2381（11）A, α = 115.225（7）, β = 92.329（5）, γ = 105.606（8）o, V = 4561.9（7） A^3, Z = 2, F（000） = 1644, Dc = 1.177 Mg/m^3, Mr = 1616.76 and μ = 1.098 mm^-1. The antitumor activities of compound 1 and its corresponding organic ligands（bpydb H2 and Htz） were investigated for inhibiting human osteosarcoma cells（MG-63 and U-2 OS） growth by MTT assay. It was found that compared with the two ligands, compound 1 exerted rather potent activities against all of these cell lines.
基金supported by the National Natural Science Foundation of China(62004143)the Key R&D Program of Hubei Province(2022BAA084)+5 种基金the Key Project of Scientific Research Plan of Hubei Provincial Department of Education(D20241501)the China Postdoctoral Science Foundation(2024M762505)the Postdoctoral Fellowship Program(Grade C)(GZC20250787)the Innovation Project of Engineering Research Center of Phosphorus Resources Development and Utilization of Ministry of Education(LCX202404)the Open Fund of the Guangdong Provincial Key Laboratory of Electronic Functional Materials and Devices(EFMD2024006Z)the Science and Technology Program Project of the State Administration for Market Regulation(2024MK086)。
文摘Accurate and sensitive determination of uric acid(UA)is critical,as abnormal UA concentrations are associated with various pathologies.Electrochemical sensing is an effective method for the detection of UA concentrations.The electrochemical behavior of UA sensors is fundamentally governed by the electronic configurations of catalytically active sites,where enhanced site activity significantly improves overall performance.In this work,biocompatible g-C_(3)N_(4)is selectively doped with cobalt to generate UA-specific surface centers.These are synergistically integrated with highly conductive Ti_(3)CNto optimize charge transport efficiency.The oxygen-terminated surface of Ti_(3)CNforms strong chemical bonds with the Co-doped sites,enabling precise modulation of their electronic structure.DFT calculations reveal substantial electron transfer from cobalt atoms to surface oxygen groups,which shifts the Co d-band center,reduces the desorption barrier for UA oxidation intermediates,and accelerates the catalytic process.The resulting Co-CN/Ti_(3)CN-modified GCE demonstrates a broad linear detection range and ultralow detection limit.This study establishes an atomic-scale design strategy for electrochemical sensors capable of trace-level UA detection,offering a promising platform for clinical diagnostics and biomedical monitoring.
基金National Social Science Foundation of China(Grant No.19XMZ095)Chongqing Social Science Planning Major Project(Grant No.2020WT22)
文摘The construction of a new type of urbanization is a necessary path for the development of modern cities,and a powerful support for coordinating the balanced development of urban and rural areas and promoting high-quality agricultural development.Based on the panel data of 30 provinces in China from 2004 to 2018,the article constructs a new urbanization and agricultural high-quality development evaluation system;then using the coupling coordination degree model and the spatial correlation analysis method,the paper empirically tests the coupling coordination of the two systems degree and its spatial relevance.The results of the study show that the average level of coupling and coordination between new urbanization and high-quality agricultural development in the period under study is at a barely coordinated level,with the highest level being moderately coordinated.There are significant inter-regional differences,with a higher level of coupling and coordination in the eastern regions and more room for improvement in the central and western regions.At this stage,the trend of"club convergence"is remarkable,with highhigh agglomeration and low-low agglomeration coexisting,and the polarization is serious.Therefore,comprehensively promoting the rural revitalization strategy,adhering to the integrated development of urban and rural areas,and enhancing inter-regional collaborative governance are powerful measures to promote the joint progress of new urbanization and high-quality agricultural development.
