Layered double hydroxides(LDHs)hold great promise as cathode materials for aqueous zinc-ion batteries(AZIBs).Nevertheless,they also face challenges of sluggish kinetics and rapid capacity loss.Herein,a conformational ...Layered double hydroxides(LDHs)hold great promise as cathode materials for aqueous zinc-ion batteries(AZIBs).Nevertheless,they also face challenges of sluggish kinetics and rapid capacity loss.Herein,a conformational entropy regulation strategy has been applied to surmount the shortcomings.A medium-entropy iron-based metal organic framework(MIL-88)derived NiCoFeInZnV-based layered double hydroxide with carbon loaded(ME-NiCoFeInZnV-LDH/C)has been first proposed and prepared with a designed method.The increased entropy optimizes electron conductivity and alleviates structure alteration and diffusion barrier during interactions with charge carriers,due to electron-induced effect and“cocktail”effect.Moreover,the nanosheet assembled hollow prismatic structures could homogenize flux distribution and electric field distribution.Therefore,the electrochemical kinetics,crystal structure stability,and activity could be dramatically improved.Leveraging the advantages of structure and composition regulation,Zn||ME-NiCoFeInZnV-LDH/C zinc battery delivers high specific capacities,rate performance,and cycling stability.This work proposes a novel and feasible medium-entropy strategy to prepare a high-performance cathode for advanced AZIBs,which is of prominent significance for the development of charge storage devices.展开更多
In this study,the typical Mg-14Gd-0.3Zr alloy was rolled at the high-temperature range of 450–500℃.The rolled Mg alloy plate with thickness of 30 mm exhibits an ultra-high ultimate tensile strength of 428 MPa and el...In this study,the typical Mg-14Gd-0.3Zr alloy was rolled at the high-temperature range of 450–500℃.The rolled Mg alloy plate with thickness of 30 mm exhibits an ultra-high ultimate tensile strength of 428 MPa and elongation of 3.4%,which has rarely been reported,and the strong fiber texture played a critical role in strengthening.The mechanisms underlying the evolution of texture during rolling were systematically investigated.At the early stage of rolling,alloys(450℃and 475℃)exhibited a[10.10]texture due to twinning assisted by Prismaticslipping.At 500℃,the alloy underwent nearly complete dynamic recrystallization(DRX)process.With increasing the rolling reduction,the DRX occurred in the whole temperature range,exhibiting the typical[10.10]–[11.20]double fiber texture.For continuous DRX,Prismaticdislocations accumulate to form grains with 30°[0001]grain boundaries,which exhibit a[10.10]fiber texture.During discontinuous DRX,Prismaticslip induced grain rotation around the[0001]axis,stabilizing either the<10.10>//RD(rolling direction)or<11.20>//RD orientations,leading to the formation of[10.10]–[11.20]double fiber texture.TEM observations confirmed that Prismaticdislocations can accumulate to form sub-grain lamellae,which gradually transform into high-angle grain boundaries by absorbing more Prismaticdislocations.First-principle calculation demonstrated that with increasing Gd content,the unstable stacking fault energy of prismatic slipping significantly decreases,promoting the activation of Prismaticslipping.These findings elucidate the critical role of twinning and Prismaticdislocations in texture evolution and the DRX process during thick plate rolling of the high-Gd content Mg-Gd-Zr alloy.展开更多
This paper presents a numerical investigation of nonlinear sloshing in a prismatic tank.A three-dimensional,twophase flow model based on Cartesian grid is developed to simulate the phenomenon.The model solves incompre...This paper presents a numerical investigation of nonlinear sloshing in a prismatic tank.A three-dimensional,twophase flow model based on Cartesian grid is developed to simulate the phenomenon.The model solves incompressible Navier-Stokes equations,utilizing the fractional step method for velocity-pressure decoupling.The finite difference method discretizes spatial derivatives,with specific schemes implemented to enhance model robustness.Model validation involves simulating benchmark cases,and comparing wave profiles and pressure results with published experimental data and numerical findings.The model demonstrates robustness and accuracy in simulating violent sloshing.The validated model examines sloshing in a partially filled prismatic tank under combined surge and roll excitations.The study employs eight frequencies encompassing the natural frequencies of tank roll and surge motions.Roll motion excitation is fixed at 2°,while surge motion considers three excitation amplitudes(0.0 m,0.01 m,and 0.02m).Analysis reveals the effects of surge amplitude and excitation frequency on wave patterns,amplitudes,and pressure peaks.Results indicate the presence of multi-component waves,including transverse,diagonal,and longitudinal waves.Furthermore,the findings demonstrate a reduction in the natural frequency for surge motion through pressure peak analysis.展开更多
Prismatic wave is that it has three of which is located at the reflection interface reflection paths and two reflection points, one and the other is located at the steep dip angle reflection layer, so that contains a ...Prismatic wave is that it has three of which is located at the reflection interface reflection paths and two reflection points, one and the other is located at the steep dip angle reflection layer, so that contains a lot of the high and steep reflection interface information that primary cannot reach. Prismatic wave field information can be separated by applying Born approximation to traditional reverse time migration profile, and then the prismatic wave is used to update velocity to improve the inversion efficiency for the salt dame flanks and some other high and steep structure. Under the guidance of this idea, a prismatic waveform inversion method is proposed （abbreviated as PWI）. PWI has a significant drawback that an iteration time of PWI is more than twice as that of FWI, meanwhile, the full wave field information cannot all be used, for this problem, we propose a joint inversion method to combine prismatic waveform inversion with full waveform inversion. In this method, FWI and PWI are applied alternately to invert the velocity. Model tests suggest that the joint inversion method is less dependence on the high and steep structure information in the initial model and improve high inversion efficiency and accuracy for the model with steep dip angle structure.展开更多
Non-cylindrical casings filled with explosives have undergone rapid development in warhead design and explosion control.The fragment spatial distribution of prismatic casings is more complex than that of traditional c...Non-cylindrical casings filled with explosives have undergone rapid development in warhead design and explosion control.The fragment spatial distribution of prismatic casings is more complex than that of traditional cylindrical casings.In this study,numerical and experimental investigations into the fragment spatial distribution of a prismatic casing were conducted.A new numerical method,which adds the Lagrangian marker points to the Eulerian grid,was proposed to track the multi-material interfaces and material dynamic fractures.Physical quantity mappings between the Lagrangian marker points and Eulerian grid were achieved by their topological relationship.Thereafter,the fragment spatial distributions of the prismatic casing with different fragment sizes,fragment shapes,and casing geometries were obtained using the numerical method.Moreover,fragment spatial distribution experiments were conducted on the prismatic casing with different fragment sizes and shapes,and the experimental data were compared with the numerical results.The effects of the fragment and casing geometry on the fragment spatial distributions were determined by analyzing the numerical results and experimental data.Finally,a formula including the casing geometry parameters was fitted to predict the fragment spatial distribution of the prismatic casing under internal explosive loading.展开更多
Prismatic precipitate platelet is always purposefully designed in the microstructure of magnesium alloys due to its greater contribution to yield stress.In this study,with an introduction of In into Mg-Sm system,a cat...Prismatic precipitate platelet is always purposefully designed in the microstructure of magnesium alloys due to its greater contribution to yield stress.In this study,with an introduction of In into Mg-Sm system,a category of novel{1010}_(α) prismatic platelets has replaced thoroughly the traditionalβ’precipitate formed in magnesium rare earth(Mg-RE)alloys.Herein,the microstructural characteristics of platelet are investigated particularly by atomic scale scanning transmission electron microscopy.It is confirmed that the platelet has a Mg_(2) InSm composition and can maintain a coherent relationship with α-Mg matrix.Importantly,on account of the similarities between In and Mg atoms,the Mg_(2) InSm prismatic platelet could be structurally categorized as a generalizedβ"precipitate with a(Mg_(2) In)Sm-type DO_(19) structure when both In and Mg are regarded as an equivalent atom.Thus,the addition of In into Mg-Sm alloy induces the formation ofβ"precipitate.Furthermore,the formedβ"prismatic platelets generally have a large average aspect ratio.The findings are of great significance to construct the effective precipitation strengthening phases and optimize the microstructure of Mg-based alloys.展开更多
A series of compression tests were conducted on 150 groups of cement paste specimens with side lengths ranging from 40 mm to 200 mm. The specimens include cube specimens and prism specimens with height to width ratio ...A series of compression tests were conducted on 150 groups of cement paste specimens with side lengths ranging from 40 mm to 200 mm. The specimens include cube specimens and prism specimens with height to width ratio of 2. The experiment results show that size effect exists in the cubic compressive strength and prismatic compressive strength of the cement paste, and larger specimens resist less in terms of strength than smaller ones. The cubic compressive strength and the prismatic compressive strength of the specimens with side length of 200 mm are respectively about 91% and 89% of the compressive strength of the specimens with the side length of 40 mm. Water to binder ratio has a significant influence on the size effect of the compressive strengths of the cement paste. With a decrease in the water to binder ratio, the size effect is significantly enhanced. When the water to binder ratio is 0.2, the size effects of the cubic compressive strength and the prismatic compressive strength of the cement paste are 1.6 and 1.4 times stronger than those of a water to binder ratio of 0.6. Furthermore, a series of formulas are proposed to calculate the size effect of the cubic compressive strength and the prismatic compressive strength of cement paste, and the results of the size effect predicted by the formulas are in good agreement with the experiment results.展开更多
This paper describes a dynamic simulation system for manufacturing prismatic components on machining centers named NCDSS. It is a subsystem of CAD/CAPP/NC integrated system for prismatic parts that we are working on. ...This paper describes a dynamic simulation system for manufacturing prismatic components on machining centers named NCDSS. It is a subsystem of CAD/CAPP/NC integrated system for prismatic parts that we are working on. Based on the system of CAD and CAPP, it can automati. cally generate NC program used on machining centers and can simulate the machining process in the sequence of technology. Techniques of automatically producing NC program for prismaic parts and the method of dynamic simulation are also discussed.展开更多
This paper investigates the motion planning of redundant free-floating manipulators with seven prismatic joints. On the earth, prismatic-jointed manipulators could only position their end-effectors in a desired way. H...This paper investigates the motion planning of redundant free-floating manipulators with seven prismatic joints. On the earth, prismatic-jointed manipulators could only position their end-effectors in a desired way. However, in space, the end-effectors of free-floating manipulators can achieve both the desired orientation and desired position due to the dynamical coupling between manipulator and satellite movement, which is formally expressed by linear and angular momentum conservation laws. In this study, a tractable algorithm particle swarm optimization combined with differential evolution （PSODE） is provided to deal with the motion planning of redundant free-floating prismatic-jointed manipulators, which could avoid the pseudo inverse of the Jacobian matrix. The polynomial functions, as argument in sine functions are used to specify the joint paths. The co- efficients of the polynomials are optimized to achieve the desired end-effector orientation and position, and simulta- neously minimize the unit-mass-kinetic energy using the redundancy. Relevant simulations prove that this method pro- vides satisfactory smooth paths for redundant free-floating prismatic-jointed manipulators. This study could help to recognize the advantages of redundant prismatic-jointed space manipulators.展开更多
The fracture toughness and fracture work of A12O3/SiC prismatic ceramic composites was evaluated in this paper, which showed the fracture energy was improved greatly. Based on the observation 'for crack propagat...The fracture toughness and fracture work of A12O3/SiC prismatic ceramic composites was evaluated in this paper, which showed the fracture energy was improved greatly. Based on the observation 'for crack propagation and fracture morphology, the fracture behavior of the prismatic composites was analyzed. In the bending test, the composites displayed a non-catastrophic behavior and a graceful failure with reasonable load-carrying capability.展开更多
The field of solid modeling has created numerous techniques for unambiguous computer representations of three-dimensional objects. Its data structures and algorithms have been used in a broad range of applications: Co...The field of solid modeling has created numerous techniques for unambiguous computer representations of three-dimensional objects. Its data structures and algorithms have been used in a broad range of applications: Computer-Aided Design and Computer-Aided Manufacturing (CAD/ CAM), robotics, computer vision, computer graphics and visualization, virtual reality, etc. This research paper is used to generate process plan from feature-based modeling, based on an integrated geometric modeling system that supports both feature-based modeling and information storage. Present system is developed only for milling components and limited to selective machining features for prismatic components and further implemented for more machining features to develop algorithms for modeling the components through the input of machining features. As a result, feature information is directly available to downstream activities, and feature extraction is no longer needed. The various systematic steps involved in this approach are study of Design, identification of Features, selection of Processes, Tools and Machines, Machining and Inspection [DFPTMMI]. Machining features generated in the design stage are recognized and stored under the Visual Basic control of CATIA software ActiveX interface. Algorithms are developed for individual features and these algorithms are embedded in Visual Basic forms. This system is discussed and suited for 2.5 Dimensional part approach, however, that can be extended to 3 dimensional prismatic part and complex features machining. Finally a process planning chart has been presented as a model process planning.展开更多
The present work is devoted to the bending problems of prismatic shell with the thickness vanishing at infinity as an exponential function. The bending equation in the zero approximation of Vekua＇s hierarchical model...The present work is devoted to the bending problems of prismatic shell with the thickness vanishing at infinity as an exponential function. The bending equation in the zero approximation of Vekua＇s hierarchical models is considered. The problem is reduced to the Dirichlet boundary value problem for elliptic type partial differential equations on half-plane. The solution of the problem under consideration is constructed in the integral form.展开更多
A method for automatically establishing a mathematical model of kinematic analysis to a planar mechanism with multiple joint and prismatic pair is presented. The breadth （ or depth ） first search spanning tree can b...A method for automatically establishing a mathematical model of kinematic analysis to a planar mechanism with multiple joint and prismatic pair is presented. The breadth （ or depth ） first search spanning tree can be obtained based on an adjacency matrix of the mechanism. Then the kinematic chain （or mechanism）＇s basic loops can be obtained. On the basis of these basic loops, a mathematical model of kinematic analysis can be established and solved automatically. In the sense of a calculative mechanism, structural analysis of the kinematic chain relates to the kinematic analysis of a mechanism. Thus, an effective way is supplied to the given mechanism＇s kinematic analysis for automatic modeling and solving, and a method is supplied to the structural type to optimize kinematic synthesis.展开更多
Six trigonal prismatic metallocages(TPMs)composed of 24 components,namely{(Cu_(3)L_(3))(Cu_(2)X_(2))_(3)(Cu_(3)L_(3))}·xG(HL=4-(quinoline-8-thio)-3,5-dimethyl-1H-pyrazole,G=benzene(B),methylbenzene(MB),1,3,5-trip...Six trigonal prismatic metallocages(TPMs)composed of 24 components,namely{(Cu_(3)L_(3))(Cu_(2)X_(2))_(3)(Cu_(3)L_(3))}·xG(HL=4-(quinoline-8-thio)-3,5-dimethyl-1H-pyrazole,G=benzene(B),methylbenzene(MB),1,3,5-triphenylbenzene(TPB),x=3 for B,MB and 1 for TPB),are reported.They were constructed by three rhombicCu_(2)X_(2)units as columns connecting two planar syn-Cu_(3)L_(3)faces,templated by G molecules.The structural analysis and EDA calculations reveal that C-H…πdominate their host-vip interactions.展开更多
Open metal sites are devised to dangle on cobalt trigonal prismatic secondary building units(SBUs)of a porous MOF,when a rigid octacarboxylate ligand,1,_(3),6,8-tetra(_(3),5-dicarboxylphenyl)pyrene,assembled with Co(N...Open metal sites are devised to dangle on cobalt trigonal prismatic secondary building units(SBUs)of a porous MOF,when a rigid octacarboxylate ligand,1,_(3),6,8-tetra(_(3),5-dicarboxylphenyl)pyrene,assembled with Co(NO_(3))_(2)under solvothermal conditions.The functional role of dangled open metal sites is exploited for CO_(2)capture studies.展开更多
A series of sodium 2-arylimino-8-quinolates,C1-C8,differing in both the nature of the aryl and quinolate substituents,was prepared and characterized by ^(1)H/^(13)C NMR spectroscopy and elemental analysis.Their X-ray ...A series of sodium 2-arylimino-8-quinolates,C1-C8,differing in both the nature of the aryl and quinolate substituents,was prepared and characterized by ^(1)H/^(13)C NMR spectroscopy and elemental analysis.Their X-ray structures reveal multimetallic assemblies adopting a variety of structural cores all based on Na-O repeat units:cubic and tetrametallic for C1,C2 and C4,hexagonal prismatic and hexametallic for C3 and C5,and for tetrametallic C7’a core resembling a cyclooctatetraene-type tub-shape.In the presence of BnOH,C1-C8 exhibit good activities towards the ring-opening polymerization(ROP)of rac-lactide,affording amorphous polylactides with broad molecular weight distributions.Furthermore,the substituent variation within the ligand frame of C1-C8 affects the catalytic activities of the ROP with the least sterically hindered system,C1,yielding the highest conversion.展开更多
The mononuclear cobalt(Ⅱ)complexes[Co(LN_(8))](BPh_(4))_(2)·C_(4)H_(10O)(1-BPh_(4))and[Co(LN_(8))](NO_(3))_(2)·CH_(3)CN(2-NO_(3))(LN_(8)=1,4,7,10-tetrakis(2-pyridinemethyl)-1,4,7,10-tetraaza-cyclododecane)h...The mononuclear cobalt(Ⅱ)complexes[Co(LN_(8))](BPh_(4))_(2)·C_(4)H_(10O)(1-BPh_(4))and[Co(LN_(8))](NO_(3))_(2)·CH_(3)CN(2-NO_(3))(LN_(8)=1,4,7,10-tetrakis(2-pyridinemethyl)-1,4,7,10-tetraaza-cyclododecane)have been synthesized and fully characterized.They differ well beyond a formal replacement of the counter anions,with their Co(Ⅱ)centers in significantly different coordination geometries.In 1-BPh_(4),the Co(Ⅱ)ion is not only coordinated by six N atoms from the LN_(8) ligand but also associated with the two remaining N atoms of LN_(8) via weak interactions.In contrast,the Co(Ⅱ)ion in 2-NO_(3) is only six-coordinated in a distorted trigonal prismatic geometry.Magnetic anisotropy and slow magnetic dynamics are drastically affected by these different environments around Co(Ⅱ).The combination of dc magnetic data,high-frequency and-field electron paramagnetic resonance(HFEPR)and theoretical calculations unambiguously reveals large negative zero-field split(ZFS)parameters D for both complexes and a large difference between the D values.Both 1-BPh_(4) and 2-NO_(3) show slow magnetic relaxation at zero field.Magnetic dilution experiments reveal effective energy barriers of 54(4)cm^(-1) for 1-BPh_(4)@Zn and 95(5)cm^(-1) for 2-NO_(3)@Zn and confirm that the slow magnetic relaxation for both complexes originates from single molecule behaviour.Ab initio computational studies explain their electronic structures and the origin of the large negative magnetic anisotropy;they support the corresponding experimental observations.Further magneto-structural analyses reveal that different distortions from the ideal trigonal prismatic geometry exert drastic effects on D values and slow relaxation,and that the additional weak intramolecular interactions between Co and N reduce the axial anisotropy.展开更多
Coordination cages with a nanocavity can encapsulate various vips,which allows modulation of the physical and chemical properties of the host–vip inclusion complexes.In this work,we designed and prepared a phosph...Coordination cages with a nanocavity can encapsulate various vips,which allows modulation of the physical and chemical properties of the host–vip inclusion complexes.In this work,we designed and prepared a phosphorescence Cu_(6)L_(3)trigonal prismatic cage,which accommodates a series of aromatic vip molecules.Single crystal X-ray analysis revealed that the intermolecular Cu⋯Cu distance can be mediated by changing the volume of the vips.Moreover,the host-vip charge-transfer interactions can be also fine-tuned via tailoring the ionization potential of vips.Consequently,we have observed the vip-induced photoluminescence properties change including a gradual red shift of the maximum emission peak and a linear relationship between the quantum yield and ionization potential of vips.展开更多
This article presents a series of six mononuclear Co(II)complexes 1-6 featuring ligands derived from a hexadentate Schiff base family,originating from the condensation of(2-formylphenoxy)acetic acid with various diami...This article presents a series of six mononuclear Co(II)complexes 1-6 featuring ligands derived from a hexadentate Schiff base family,originating from the condensation of(2-formylphenoxy)acetic acid with various diamines.Notably,these complexes uniquely prefer a trigonal prism geometry,presenting a novel approach to synthesizing complexes with this distinctive shape.The compounds were characterized by elemental analysis,FT-IR spectroscopy,and single-crystal and powder XRD techniques.Furthermore,the magnetism was investigated by DC and AC magnetic measurements and also complemented by X-band EPR spectroscopy.The results reveal that the prepared complexes behave as field-induced single-molecule magnets,characterized by a substantial negative axial zero-field splitting D-parameter and spin reversal energetic barrier U_(eff) reaching values up to 72 K.The theoretical methods based on CASSCF/NEVPT2 calculations were applied to rationalize their magnetic properties.Moreover,these complexes hold promising potential for further functionalization,offering opportunities to enhance their properties,particularly towards developing zero-field single-molecule magnets as evidenced by the slow relaxation of magnetization in zero static magnetic field observed for the zinc-diluted complex 1Zn.展开更多
The interrupted fatigue test method was utilized to investigate the damage evolution mechanism of the notch high-cycle fatigue(NHCF)in Ti-55531 alloy with a multilevel lamellar microstructure.The results reveal that s...The interrupted fatigue test method was utilized to investigate the damage evolution mechanism of the notch high-cycle fatigue(NHCF)in Ti-55531 alloy with a multilevel lamellar microstructure.The results reveal that significant microvoids and microcracks predominantly initiate at α/β interfaces under various notch root radii(R).Notably,even under larger R(0.75 mm),mutual interactions of stacking faults(SFs)−deformation twins,twins−twins,and SFs−SFs are observed.Furthermore,with decreasing R(0.34 and 0.14 mm),the volume fraction of SFs escalates significantly and twins are almost absent.Moreover,activated prismatic slip system decreases with a decrease in Schmidt factor and with the further decrease in R.Finally,strain localization near α/β interfaces contributes to the initiation of fatigue microcracks.展开更多
基金the funding support from the National Natural Science Foundation of China(Grant No.52202217,52471222)the Natural Science Foundation of Jilin Province(Grant No.YDZJ202201ZYTS375).
文摘Layered double hydroxides(LDHs)hold great promise as cathode materials for aqueous zinc-ion batteries(AZIBs).Nevertheless,they also face challenges of sluggish kinetics and rapid capacity loss.Herein,a conformational entropy regulation strategy has been applied to surmount the shortcomings.A medium-entropy iron-based metal organic framework(MIL-88)derived NiCoFeInZnV-based layered double hydroxide with carbon loaded(ME-NiCoFeInZnV-LDH/C)has been first proposed and prepared with a designed method.The increased entropy optimizes electron conductivity and alleviates structure alteration and diffusion barrier during interactions with charge carriers,due to electron-induced effect and“cocktail”effect.Moreover,the nanosheet assembled hollow prismatic structures could homogenize flux distribution and electric field distribution.Therefore,the electrochemical kinetics,crystal structure stability,and activity could be dramatically improved.Leveraging the advantages of structure and composition regulation,Zn||ME-NiCoFeInZnV-LDH/C zinc battery delivers high specific capacities,rate performance,and cycling stability.This work proposes a novel and feasible medium-entropy strategy to prepare a high-performance cathode for advanced AZIBs,which is of prominent significance for the development of charge storage devices.
基金the National Key Research and Development Program(2023YFB3710903)the National Natural Science Foundation of China(U2167213)+1 种基金the Fundamental Research Funds for the Central Universities(N25GFZ006)the Xingliao Talent Plan Program(XLYC2203202).
文摘In this study,the typical Mg-14Gd-0.3Zr alloy was rolled at the high-temperature range of 450–500℃.The rolled Mg alloy plate with thickness of 30 mm exhibits an ultra-high ultimate tensile strength of 428 MPa and elongation of 3.4%,which has rarely been reported,and the strong fiber texture played a critical role in strengthening.The mechanisms underlying the evolution of texture during rolling were systematically investigated.At the early stage of rolling,alloys(450℃and 475℃)exhibited a[10.10]texture due to twinning assisted by Prismaticslipping.At 500℃,the alloy underwent nearly complete dynamic recrystallization(DRX)process.With increasing the rolling reduction,the DRX occurred in the whole temperature range,exhibiting the typical[10.10]–[11.20]double fiber texture.For continuous DRX,Prismaticdislocations accumulate to form grains with 30°[0001]grain boundaries,which exhibit a[10.10]fiber texture.During discontinuous DRX,Prismaticslip induced grain rotation around the[0001]axis,stabilizing either the<10.10>//RD(rolling direction)or<11.20>//RD orientations,leading to the formation of[10.10]–[11.20]double fiber texture.TEM observations confirmed that Prismaticdislocations can accumulate to form sub-grain lamellae,which gradually transform into high-angle grain boundaries by absorbing more Prismaticdislocations.First-principle calculation demonstrated that with increasing Gd content,the unstable stacking fault energy of prismatic slipping significantly decreases,promoting the activation of Prismaticslipping.These findings elucidate the critical role of twinning and Prismaticdislocations in texture evolution and the DRX process during thick plate rolling of the high-Gd content Mg-Gd-Zr alloy.
基金financially supported by the Shandong Provincial Natural Science Foundation(Grant No.ZR2023QE063)。
文摘This paper presents a numerical investigation of nonlinear sloshing in a prismatic tank.A three-dimensional,twophase flow model based on Cartesian grid is developed to simulate the phenomenon.The model solves incompressible Navier-Stokes equations,utilizing the fractional step method for velocity-pressure decoupling.The finite difference method discretizes spatial derivatives,with specific schemes implemented to enhance model robustness.Model validation involves simulating benchmark cases,and comparing wave profiles and pressure results with published experimental data and numerical findings.The model demonstrates robustness and accuracy in simulating violent sloshing.The validated model examines sloshing in a partially filled prismatic tank under combined surge and roll excitations.The study employs eight frequencies encompassing the natural frequencies of tank roll and surge motions.Roll motion excitation is fixed at 2°,while surge motion considers three excitation amplitudes(0.0 m,0.01 m,and 0.02m).Analysis reveals the effects of surge amplitude and excitation frequency on wave patterns,amplitudes,and pressure peaks.Results indicate the presence of multi-component waves,including transverse,diagonal,and longitudinal waves.Furthermore,the findings demonstrate a reduction in the natural frequency for surge motion through pressure peak analysis.
基金financially supported by the National 973 Project(No.2014CB239006 and 2011CB202402)the Natural Science Foundation of China(No.41104069 and 41274124)the Graduate Student Innovation Project Funding of China University of Petroleum(No.YCXJ2016001)
文摘Prismatic wave is that it has three of which is located at the reflection interface reflection paths and two reflection points, one and the other is located at the steep dip angle reflection layer, so that contains a lot of the high and steep reflection interface information that primary cannot reach. Prismatic wave field information can be separated by applying Born approximation to traditional reverse time migration profile, and then the prismatic wave is used to update velocity to improve the inversion efficiency for the salt dame flanks and some other high and steep structure. Under the guidance of this idea, a prismatic waveform inversion method is proposed （abbreviated as PWI）. PWI has a significant drawback that an iteration time of PWI is more than twice as that of FWI, meanwhile, the full wave field information cannot all be used, for this problem, we propose a joint inversion method to combine prismatic waveform inversion with full waveform inversion. In this method, FWI and PWI are applied alternately to invert the velocity. Model tests suggest that the joint inversion method is less dependence on the high and steep structure information in the initial model and improve high inversion efficiency and accuracy for the model with steep dip angle structure.
基金supported by the National Natural Science Foundation of China(Grant No.11822203and 11702026)。
文摘Non-cylindrical casings filled with explosives have undergone rapid development in warhead design and explosion control.The fragment spatial distribution of prismatic casings is more complex than that of traditional cylindrical casings.In this study,numerical and experimental investigations into the fragment spatial distribution of a prismatic casing were conducted.A new numerical method,which adds the Lagrangian marker points to the Eulerian grid,was proposed to track the multi-material interfaces and material dynamic fractures.Physical quantity mappings between the Lagrangian marker points and Eulerian grid were achieved by their topological relationship.Thereafter,the fragment spatial distributions of the prismatic casing with different fragment sizes,fragment shapes,and casing geometries were obtained using the numerical method.Moreover,fragment spatial distribution experiments were conducted on the prismatic casing with different fragment sizes and shapes,and the experimental data were compared with the numerical results.The effects of the fragment and casing geometry on the fragment spatial distributions were determined by analyzing the numerical results and experimental data.Finally,a formula including the casing geometry parameters was fitted to predict the fragment spatial distribution of the prismatic casing under internal explosive loading.
基金financially supported by the Liaoning Provincial Natural Science Foundation of China(No.2020-MS-085)。
文摘Prismatic precipitate platelet is always purposefully designed in the microstructure of magnesium alloys due to its greater contribution to yield stress.In this study,with an introduction of In into Mg-Sm system,a category of novel{1010}_(α) prismatic platelets has replaced thoroughly the traditionalβ’precipitate formed in magnesium rare earth(Mg-RE)alloys.Herein,the microstructural characteristics of platelet are investigated particularly by atomic scale scanning transmission electron microscopy.It is confirmed that the platelet has a Mg_(2) InSm composition and can maintain a coherent relationship with α-Mg matrix.Importantly,on account of the similarities between In and Mg atoms,the Mg_(2) InSm prismatic platelet could be structurally categorized as a generalizedβ"precipitate with a(Mg_(2) In)Sm-type DO_(19) structure when both In and Mg are regarded as an equivalent atom.Thus,the addition of In into Mg-Sm alloy induces the formation ofβ"precipitate.Furthermore,the formedβ"prismatic platelets generally have a large average aspect ratio.The findings are of great significance to construct the effective precipitation strengthening phases and optimize the microstructure of Mg-based alloys.
基金Project(51408213)supported by the National Natural Science Foundation of China
文摘A series of compression tests were conducted on 150 groups of cement paste specimens with side lengths ranging from 40 mm to 200 mm. The specimens include cube specimens and prism specimens with height to width ratio of 2. The experiment results show that size effect exists in the cubic compressive strength and prismatic compressive strength of the cement paste, and larger specimens resist less in terms of strength than smaller ones. The cubic compressive strength and the prismatic compressive strength of the specimens with side length of 200 mm are respectively about 91% and 89% of the compressive strength of the specimens with the side length of 40 mm. Water to binder ratio has a significant influence on the size effect of the compressive strengths of the cement paste. With a decrease in the water to binder ratio, the size effect is significantly enhanced. When the water to binder ratio is 0.2, the size effects of the cubic compressive strength and the prismatic compressive strength of the cement paste are 1.6 and 1.4 times stronger than those of a water to binder ratio of 0.6. Furthermore, a series of formulas are proposed to calculate the size effect of the cubic compressive strength and the prismatic compressive strength of cement paste, and the results of the size effect predicted by the formulas are in good agreement with the experiment results.
文摘This paper describes a dynamic simulation system for manufacturing prismatic components on machining centers named NCDSS. It is a subsystem of CAD/CAPP/NC integrated system for prismatic parts that we are working on. Based on the system of CAD and CAPP, it can automati. cally generate NC program used on machining centers and can simulate the machining process in the sequence of technology. Techniques of automatically producing NC program for prismaic parts and the method of dynamic simulation are also discussed.
基金supported by the National Natural Science Foundation of China (11072122)
文摘This paper investigates the motion planning of redundant free-floating manipulators with seven prismatic joints. On the earth, prismatic-jointed manipulators could only position their end-effectors in a desired way. However, in space, the end-effectors of free-floating manipulators can achieve both the desired orientation and desired position due to the dynamical coupling between manipulator and satellite movement, which is formally expressed by linear and angular momentum conservation laws. In this study, a tractable algorithm particle swarm optimization combined with differential evolution （PSODE） is provided to deal with the motion planning of redundant free-floating prismatic-jointed manipulators, which could avoid the pseudo inverse of the Jacobian matrix. The polynomial functions, as argument in sine functions are used to specify the joint paths. The co- efficients of the polynomials are optimized to achieve the desired end-effector orientation and position, and simulta- neously minimize the unit-mass-kinetic energy using the redundancy. Relevant simulations prove that this method pro- vides satisfactory smooth paths for redundant free-floating prismatic-jointed manipulators. This study could help to recognize the advantages of redundant prismatic-jointed space manipulators.
文摘The fracture toughness and fracture work of A12O3/SiC prismatic ceramic composites was evaluated in this paper, which showed the fracture energy was improved greatly. Based on the observation 'for crack propagation and fracture morphology, the fracture behavior of the prismatic composites was analyzed. In the bending test, the composites displayed a non-catastrophic behavior and a graceful failure with reasonable load-carrying capability.
文摘The field of solid modeling has created numerous techniques for unambiguous computer representations of three-dimensional objects. Its data structures and algorithms have been used in a broad range of applications: Computer-Aided Design and Computer-Aided Manufacturing (CAD/ CAM), robotics, computer vision, computer graphics and visualization, virtual reality, etc. This research paper is used to generate process plan from feature-based modeling, based on an integrated geometric modeling system that supports both feature-based modeling and information storage. Present system is developed only for milling components and limited to selective machining features for prismatic components and further implemented for more machining features to develop algorithms for modeling the components through the input of machining features. As a result, feature information is directly available to downstream activities, and feature extraction is no longer needed. The various systematic steps involved in this approach are study of Design, identification of Features, selection of Processes, Tools and Machines, Machining and Inspection [DFPTMMI]. Machining features generated in the design stage are recognized and stored under the Visual Basic control of CATIA software ActiveX interface. Algorithms are developed for individual features and these algorithms are embedded in Visual Basic forms. This system is discussed and suited for 2.5 Dimensional part approach, however, that can be extended to 3 dimensional prismatic part and complex features machining. Finally a process planning chart has been presented as a model process planning.
文摘The present work is devoted to the bending problems of prismatic shell with the thickness vanishing at infinity as an exponential function. The bending equation in the zero approximation of Vekua＇s hierarchical models is considered. The problem is reduced to the Dirichlet boundary value problem for elliptic type partial differential equations on half-plane. The solution of the problem under consideration is constructed in the integral form.
基金supported by the Foundation for Docotors of Xiangtan University under Grant No. 08QDZ42the Project of Engineering Research Center of Ministry of Education under Grant No. 09-FZGJ04
文摘A method for automatically establishing a mathematical model of kinematic analysis to a planar mechanism with multiple joint and prismatic pair is presented. The breadth （ or depth ） first search spanning tree can be obtained based on an adjacency matrix of the mechanism. Then the kinematic chain （or mechanism）＇s basic loops can be obtained. On the basis of these basic loops, a mathematical model of kinematic analysis can be established and solved automatically. In the sense of a calculative mechanism, structural analysis of the kinematic chain relates to the kinematic analysis of a mechanism. Thus, an effective way is supplied to the given mechanism＇s kinematic analysis for automatic modeling and solving, and a method is supplied to the structural type to optimize kinematic synthesis.
基金supported by the National Natural Science Foundation of China(No.21731002,21975104,22071141,21471094)the Guangdong Major Project of Basic and Applied Research(No.2019B030302009)+1 种基金the Guangdong Basic and Applied Basic Research Foundation(No.2019A1515012162)the Open Fund of Guangdong Provincial Key Laboratory of Functional Supramolecular Coordination Materials and Applications(No.2020A05)。
文摘Six trigonal prismatic metallocages(TPMs)composed of 24 components,namely{(Cu_(3)L_(3))(Cu_(2)X_(2))_(3)(Cu_(3)L_(3))}·xG(HL=4-(quinoline-8-thio)-3,5-dimethyl-1H-pyrazole,G=benzene(B),methylbenzene(MB),1,3,5-triphenylbenzene(TPB),x=3 for B,MB and 1 for TPB),are reported.They were constructed by three rhombicCu_(2)X_(2)units as columns connecting two planar syn-Cu_(3)L_(3)faces,templated by G molecules.The structural analysis and EDA calculations reveal that C-H…πdominate their host-vip interactions.
基金the University of South Florida and the National Science Foundation(DMR-1352065)for financial support of this workWe thank Prof.Randy W.Larsen and Christi L.Whittington for assistance with fluorescence tests and helpful discussions.The single-crystal X-ray diffraction of 1 was carried out at the Advanced Photon Source ChemMatCARS Sector 15,supported by the National Science Foundation/Department of Energy under grant number NSF/CHE-1346572.Use of the Advanced Photon Source,an Office of Science User Facility operated for the U.S.Department of Energy(DOE)Office of Science by Argonne National Laboratory,was supported by the U.S.DOE under Contract no.DE-AC02-06CH11357.
文摘Open metal sites are devised to dangle on cobalt trigonal prismatic secondary building units(SBUs)of a porous MOF,when a rigid octacarboxylate ligand,1,_(3),6,8-tetra(_(3),5-dicarboxylphenyl)pyrene,assembled with Co(NO_(3))_(2)under solvothermal conditions.The functional role of dangled open metal sites is exploited for CO_(2)capture studies.
基金supported by the National Natural Science Foundation of China(no.51273202 and U1362204)the Chinese Academy of Sciences for a Visiting Scientist Fellowship.
文摘A series of sodium 2-arylimino-8-quinolates,C1-C8,differing in both the nature of the aryl and quinolate substituents,was prepared and characterized by ^(1)H/^(13)C NMR spectroscopy and elemental analysis.Their X-ray structures reveal multimetallic assemblies adopting a variety of structural cores all based on Na-O repeat units:cubic and tetrametallic for C1,C2 and C4,hexagonal prismatic and hexametallic for C3 and C5,and for tetrametallic C7’a core resembling a cyclooctatetraene-type tub-shape.In the presence of BnOH,C1-C8 exhibit good activities towards the ring-opening polymerization(ROP)of rac-lactide,affording amorphous polylactides with broad molecular weight distributions.Furthermore,the substituent variation within the ligand frame of C1-C8 affects the catalytic activities of the ROP with the least sterically hindered system,C1,yielding the highest conversion.
基金supported by the National Natural Science Foundation of China(21973046,22105089,and 21601070)the Jiangxi Provincial Key Laboratory of Functional Molecular Materials Chemistry(20212BCD42018)d the Key R&D Plan of Zhenjiang City(GY2019021).
文摘The mononuclear cobalt(Ⅱ)complexes[Co(LN_(8))](BPh_(4))_(2)·C_(4)H_(10O)(1-BPh_(4))and[Co(LN_(8))](NO_(3))_(2)·CH_(3)CN(2-NO_(3))(LN_(8)=1,4,7,10-tetrakis(2-pyridinemethyl)-1,4,7,10-tetraaza-cyclododecane)have been synthesized and fully characterized.They differ well beyond a formal replacement of the counter anions,with their Co(Ⅱ)centers in significantly different coordination geometries.In 1-BPh_(4),the Co(Ⅱ)ion is not only coordinated by six N atoms from the LN_(8) ligand but also associated with the two remaining N atoms of LN_(8) via weak interactions.In contrast,the Co(Ⅱ)ion in 2-NO_(3) is only six-coordinated in a distorted trigonal prismatic geometry.Magnetic anisotropy and slow magnetic dynamics are drastically affected by these different environments around Co(Ⅱ).The combination of dc magnetic data,high-frequency and-field electron paramagnetic resonance(HFEPR)and theoretical calculations unambiguously reveals large negative zero-field split(ZFS)parameters D for both complexes and a large difference between the D values.Both 1-BPh_(4) and 2-NO_(3) show slow magnetic relaxation at zero field.Magnetic dilution experiments reveal effective energy barriers of 54(4)cm^(-1) for 1-BPh_(4)@Zn and 95(5)cm^(-1) for 2-NO_(3)@Zn and confirm that the slow magnetic relaxation for both complexes originates from single molecule behaviour.Ab initio computational studies explain their electronic structures and the origin of the large negative magnetic anisotropy;they support the corresponding experimental observations.Further magneto-structural analyses reveal that different distortions from the ideal trigonal prismatic geometry exert drastic effects on D values and slow relaxation,and that the additional weak intramolecular interactions between Co and N reduce the axial anisotropy.
基金supported by the National Natural Science Foundation of China(No.21731002,21975104,21871172,and 21701049)the China Postdoctoral Science Foundation(2018M633272,2017M622894)and Jinan University+2 种基金support from Guangdong Basic and Applied Basic Research Foundation(2019B151502024)Guangdong Province Pearl River Scholar Funded Scheme(2019)the Fundamental Research Funds for the Central Universities(21619315).
文摘Coordination cages with a nanocavity can encapsulate various vips,which allows modulation of the physical and chemical properties of the host–vip inclusion complexes.In this work,we designed and prepared a phosphorescence Cu_(6)L_(3)trigonal prismatic cage,which accommodates a series of aromatic vip molecules.Single crystal X-ray analysis revealed that the intermolecular Cu⋯Cu distance can be mediated by changing the volume of the vips.Moreover,the host-vip charge-transfer interactions can be also fine-tuned via tailoring the ionization potential of vips.Consequently,we have observed the vip-induced photoluminescence properties change including a gradual red shift of the maximum emission peak and a linear relationship between the quantum yield and ionization potential of vips.
基金financial support from the PalackýUniversity Olomouc project IGA_PrF_2022_006E.Č.was supported by the Slovak Research and Development Agency,contract no.APVV-22-0172 and APVV-18-0197。
文摘This article presents a series of six mononuclear Co(II)complexes 1-6 featuring ligands derived from a hexadentate Schiff base family,originating from the condensation of(2-formylphenoxy)acetic acid with various diamines.Notably,these complexes uniquely prefer a trigonal prism geometry,presenting a novel approach to synthesizing complexes with this distinctive shape.The compounds were characterized by elemental analysis,FT-IR spectroscopy,and single-crystal and powder XRD techniques.Furthermore,the magnetism was investigated by DC and AC magnetic measurements and also complemented by X-band EPR spectroscopy.The results reveal that the prepared complexes behave as field-induced single-molecule magnets,characterized by a substantial negative axial zero-field splitting D-parameter and spin reversal energetic barrier U_(eff) reaching values up to 72 K.The theoretical methods based on CASSCF/NEVPT2 calculations were applied to rationalize their magnetic properties.Moreover,these complexes hold promising potential for further functionalization,offering opportunities to enhance their properties,particularly towards developing zero-field single-molecule magnets as evidenced by the slow relaxation of magnetization in zero static magnetic field observed for the zinc-diluted complex 1Zn.
基金supported by the National Natural Science Foundation of China(Nos.52061005,52261025)the Science and Technology Programs of Guizhou Province,China(Nos.YQK[2023]009,CXTD[2023]009)the Technology Innovation Leading Program of Shaanxi Province,China(No.2024ZCYYDP92)。
文摘The interrupted fatigue test method was utilized to investigate the damage evolution mechanism of the notch high-cycle fatigue(NHCF)in Ti-55531 alloy with a multilevel lamellar microstructure.The results reveal that significant microvoids and microcracks predominantly initiate at α/β interfaces under various notch root radii(R).Notably,even under larger R(0.75 mm),mutual interactions of stacking faults(SFs)−deformation twins,twins−twins,and SFs−SFs are observed.Furthermore,with decreasing R(0.34 and 0.14 mm),the volume fraction of SFs escalates significantly and twins are almost absent.Moreover,activated prismatic slip system decreases with a decrease in Schmidt factor and with the further decrease in R.Finally,strain localization near α/β interfaces contributes to the initiation of fatigue microcracks.
