150 results about "Octahedron" patented technology

The application provides a Pd6(SR) 12 cluster with an octahedral structure, the Pd6(SR) 12 cluster is a cyclohexanethiol ligand-protected palladium cluster, contains 6 Pd atoms, 12 cyclohexanethiol ligands, the 6 Pd atoms form an octahedral core, and the sulfur atoms in the cyclohexanethiol ligands are connected with the Pd atoms peripherally, and each sulfur atom is connected with two Pd atoms. The application further discloses a preparation method of the Pd6(SR) 12 cluster, and the application fills the technical vacancy of synthesizing Pd clusters with structures other than a ring structure, and has high popularization value.

The invention provides a transition metal Fe doped vanadyl phosphate material and a preparation method thereof. Fe partially replaces V metal cations in crystal lattices, a local coordination environment and an electronic structure are adjusted, a stable Fe-O-P-O-V delocalized electronic structure is formed, and Zn < 2 + > intercalation / deintercalation reversibility and crystal lattice stability are optimized. Compared with the traditional VOPO4, the Fe-doped vanadyl phosphate material has the advantages that the V-O bond strength is obviously enhanced, the interplanar spacing is reduced, the dissolution of PO4 < 3 > and the fracture of a lattice structure are inhibited, the symmetry of a VO6 octahedron is obviously improved, and excellent circulation (the capacity retention ratio reaches 80% after 2000 times of circulation) and rate capability are shown. The preparation process is simple, low in cost, mild in reaction condition, high in yield and low in equipment dependence; the obtained positive electrode material is improved in capacity, enhanced in structural stability and improved in rate capability, and an innovative solution is provided for developing a high-stability aqueous ion battery positive electrode material.

This invention discloses a CuS nanostructure material, its preparation method, and its applications. The CuS nanostructure material uses Cu-MOF octahedrons as a precursor, which are hydrothermally sulfided to obtain an octahedral hierarchical structure assembled from CuS nanorods. The CuS nanorods have a size of 50-100 nm, and the edge length of the precursor Cu-MOF octahedrons is 0.8-1 μm. This invention utilizes a one-step hydrothermal method to prepare a CuS nanostructure material through Cu-MOF sulfidation, resulting in a zinc-ion battery anode material with high conversion efficiency and excellent electrochemical performance.

This invention belongs to the field of superhard material synthesis technology, specifically disclosing a high-temperature, high-pressure preparation method for nano-polycrystalline diamond with synergistic mechanical and thermal properties. The method includes the following steps: precursor preparation: pre-pressing the precursor in a cemented carbide mold; octahedral assembly; wrapping the pre-pressed sample with platinum foil and placing it at the center of the octahedron; high-temperature, high-pressure sintering; stopping heating after heat preservation, allowing it to cool naturally to 23-25°C, then depressurizing, removing the octahedral assembly and the platinum foil wrapping, thus obtaining the synergistically enhanced nano-polycrystalline diamond. This invention employs the above-mentioned high-temperature, high-pressure preparation method for nano-polycrystalline diamond with synergistic mechanical and thermal properties. By combining nanodiamond powder with graphene, the sample assembly is optimized, and nano-polycrystalline diamond samples with excellent mechanical properties and significantly improved thermal conductivity are synthesized under relatively mild temperature and pressure conditions.

The invention discloses a face-to-face binuclear cobalt complex and a preparation method and application thereof, and belongs to the technical field of organic synthesis and catalysis, the face-to-face binuclear cobalt complex is a crystal material A or a crystal material B, the chemical formula of the crystal material A is C68H68Co2N4O6, and the chemical formula of the crystal material B is C54H76Co2N6O6; the face-to-face dual-core cobalt complex comprises a crystal material A and a crystal material B. The center distance between two metal cobalt of the crystal material A is 4.821, a ligand is connected with the two metal centers in a bridging mode to form a large cavity, the dual-metal cobalt complex is formed, the two metal cobalt are subjected to synergistic activation at + 2 valence, and the dual-metal cobalt complex is formed. And hydroxyl radicals can be generated through homolysis. Wherein the ligand of the crystal material B is connected with two metal cobalt centers in a carbon chain bridging mode, the coordination environment of each metal cobalt center is in an octahedral configuration, the distance between the two metal centers is 5.720, the two metal centers are in + 3 valence at the same time, and the binuclear cobalt complex is formed.

The invention relates to the technical field of boiler equipment, in particular to a boiler air heater based on an octahedral array structure. According to the technical scheme, the boiler air heater based on the octahedral array structure comprises heat exchange pipeline units, the boiler air heater is formed by arranging the multiple heat exchange pipeline units in parallel in the steam flowing direction, each heat exchange pipeline unit comprises a regular octahedral pipeline and a cylindrical pipe, and multiple sets of regular octahedral pipelines are arranged on one side of each cylindrical pipe; the heat exchange unit formed by connecting a plurality of regular octahedron pipelines in series is adopted, each regular octahedron is of a structure with a complex space flow channel formed by connecting a plurality of edge pipes, when steam flows through each octahedron unit, the steam is subjected to multiple times of flow division and re-convergence processes, and therefore the heat transfer coefficient of the steam in the pipes is effectively increased, and the heat exchange efficiency of the steam is improved. And meanwhile, the non-straight structure on the outer surface of the octahedral pipeline also enhances the flow disturbance of the air side, the convection heat exchange efficiency outside the pipeline is improved, and the heat exchange capacity and the heat energy utilization efficiency of the air heater are remarkably improved.

The application provides an ultramicroporous zinc-based MOF material, a preparation method thereof and application thereof in ammonia adsorption, and belongs to the technical field of crystalline materials. The material is an ultramicroporous zinc-based metal organic framework material with a three-dimensional periodic network structure, which is formed by coordination self-assembly of Zn 2+ ions, squarate ligands and triazoles ligands, wherein Zn 2+ ions exist in two coordination modes of hexa-coordinated octahedron and tetra-coordinated tetrahedron; the molecular formula of the material is [Zn2(C4O4)(C2H2N3)2], wherein C4O4 2‑ is a squarate ligand, and C2H2N3 ‑ is a triazole ligand. The application also provides application of the ultramicroporous zinc-based MOF material in ammonia adsorption. The MOF material has good stability, can maintain the integrity of the framework structure after being soaked in water for 7 days, and has good ammonia adsorption performance.

The invention discloses a cobalt-doped ruthenium dioxide nanoparticle material as well as a preparation method and application thereof, and relates to a ruthenium dioxide nanoparticle material as well as a preparation method and application thereof. The nano-particle cluster is formed by irregularly distributing nano-particles; the nanoparticles have a single-phase crystal structure, and the spacing distribution of {110} crystal faces is 0.315 nm; the material is composed of three elements of Co, Ru and O, wherein Co is doped into RuO2 to form Co < 0.3 > Ru0. 7O2 nanoparticles; the material is of an octahedral structure, and Ru sites are replaced by Co doping; the chemical valence state of Ru on the surface of the material is a mixed valence state of + 3 and + 4; charge transfer occurs among three ions of Co, Ru and O, so that Ru is in a lower oxidation state. The cobalt-doped ruthenium dioxide nanoparticle material is used for electrolyzing water to produce hydrogen, and shows 2500-hour long-term stability under the current density of 10 mAcm <-2 >.

This invention discloses an antimony-doped wide-bandgap zirconium chloride powder-emitting crystal material, its preparation method, and its application. The chemical formula of the powder-emitting crystal material is (C9H). 15 N3)2ZrCl8:Sb 3+ It belongs to the monoclinic crystal system, with space group P21 / c; in the described photoluminescent crystal material, each zirconium atom is coordinated with 8 chlorine atoms to form [ZrCl8]. 4‑ Polyhedral structure, organic cation (C9H) 15 N3) + It is linked to inorganic anions via C–N–H···Cl bonds, forming discrete [ZrCl8]. 4‑ The octahedral structure is replaced by organic cations (C9H). 15 N3) + Complete isolation is achieved, forming a zero-dimensional ionic crystal structure. This invention overcomes the problems of single luminescent center, limited emission wavelength, and insufficient luminescence intensity in undoped zirconium-based chlorides by introducing antimony. Antimony, as an effective luminescent center, can promote the radiative recombination process and achieve high-brightness broadband emission.

The invention provides a heteroatom-doped vacancy-rich V2O3-x composite electrode material supported by a carbon skeleton and a preparation method and application thereof, and belongs to the technical field of composite electrode materials. According to the preparation method, in-situ growth is carried out on a V2O3 octahedron supported by a carbon skeleton by utilizing high-temperature thermal reduction so as to strengthen interface charge transfer, and meanwhile, volume deformation in a circulation process is relieved by virtue of a stable carbon coating layer, so that the heteroatom-doped vacancy-rich V2O3-x composite electrode material supported by the carbon skeleton is prepared; the composite electrode material takes porous carbon as a skeleton, and heteroatom-doped V2O3 nanoparticles are uniformly embedded in the carbon skeleton; the composite electrode material has rich vacancy defects and a stable interlayer structure and can be used for preparing the aqueous zinc ion soft package battery, and the aqueous zinc ion soft package battery shows high specific capacity, excellent cycle stability and good rate capability and has good practicability.

The invention provides an electrochemical mechanical polishing composition, application and a method, and relates to the technical field of polishing processing. The electrochemical mechanical polishing composition comprises a liquid carrier, a pH (Potential of Hydrogen) regulator, an organic electrolyte and chamfered octahedral cerium oxide abrasive particles, and the chamfered octahedral cerium oxide abrasive particles are dispersed in the liquid carrier, the ratio of the cumulative volume of abrasive grains having at least two times the average particle diameter as measured by a scanning electron microscope among the chamfered octahedral cerium oxide abrasive grains to the cumulative volume of abrasive grains having at least two times the average particle diameter as measured by the scanning electron microscope among the chamfered octahedral cerium oxide abrasive grains is at least 0.1.

Disclosed is a method for designing the composition of a layered structure of Li3YCl6 compound exhibiting enhanced ionic conductivity, which provides a method for designing the composition of a lithium yttrium halide solid electrolyte with a hexagonal close-packed structure, the method being executed by a processor, the method including: calculating possible diffusion paths for lithium ions to migrate an adjacent octahedral site in the a-b plane in each consecutive layer constituting a unit cell with a hexagonal close-packed structure; calculating the activation barrier energy for lithium ion diffusion for each of the calculated diffusion paths; and determining the occupancy of yttrium within the unit cell to form a percolation state where diffusion paths with a low calculated activation barrier energy are connected within the unit cell.

A method for preparing high-dielectric, moderately saturated magnetized yttrium iron garnet ferrite belongs to the field of microwave and magnetic materials technology. This invention utilizes a method that substitutes the dodecahedral Y-site in the garnet structure. 3+ Octahedral and tetrahedral Fe 3+ The formulation and secondary granulation process result in a material with moderate saturation magnetization (1050G < 4πMs < 1250G), suitable for low-frequency microwave ferrite devices. It also possesses high dielectric constant ε' > 20, low ferromagnetic resonance linewidth ΔH ≤ 24Oe, and low dielectric loss tanδ. ε <1×10 ‑4 This can reduce the design size of the device, which is beneficial for the miniaturization and weight reduction of microwave ferrite devices.

The invention discloses a geotechnical material cutting and crushing simulation method and device considering coordination number and particle shape. The method comprises the following steps: acquiring particle space data, carrying out geometric simplification, and constructing an irregular particle shape library containing point-surface information; generating a DEM sample for numerical simulation based on the irregular particle shape library; determining a crushing triggering threshold value; determining octahedral shear stress q of the particles, and triggering particle crushing when q is greater than a crushing triggering threshold value; the particle cutting times are distributed with the coordination number as a dominant variable; a main fracture surface is determined, and crushing operation is executed; the orientation of the main fracture surface is consistent with the maximum main stress direction, and the main fracture surface passes through the maximum contact force point; and determining a secondary fracture surface, and executing secondary or multiple crushing operations according to the number of times of cutting until simulation is completed. According to the method, the calculation overhead is remarkably reduced while the irregular geometry and the controllable crushing degree are kept, and the influence of the shape effect and the scale effect on the strength and particle size distribution evolution can be reflected.

The invention relates to the technical field of high-flux photonics materials, in particular to a Sb < 3 + >-doped Cs3LnCl6 zero-dimensional nanocrystal as well as a preparation method and application thereof. The chemical formula of the Sb < 3 + >-doped Cs3LnCl6 zero-dimensional nanocrystal is Cs3Ln1-xSbxCl6, x ranges from 0.005 to 0.1, Ln is selected from at least one of Y, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, and the Sb < 3 + >-doped Cs3LnCl6 zero-dimensional nanocrystal has the chemical formula of Cs3Ln1-xSbxCl6. The material has a zero-dimensional structure of a C2 / c space group, and is composed of an isolated [BCl6] 3-octahedron and a gap Cs < + >, the zero-dimensional nanocrystal has a deep trap state of 0.6 eV to 1.2 eV. Through zero-dimensional [BCl6] 3-octahedron lattice rigidity and deep trap carrier recovery, high-temperature anti-thermal quenching can be realized without external coating, and the problem of external passivation-performance side effects of the existing material is solved.

The invention discloses an intramolecular entropy driving amplifier based on DNA octahedron assembly as well as a preparation method and application thereof. The preparation method comprises the following steps: annealing three DNA single chains P1, P2 and P3 to form a component C1, annealing three DNA single chains P4, P5 and P6 to form a component C2, and annealing four DNA single chains P7, P8, P9 and P10 to form a component C3; and mixing the component C1, the component C2 and the component C3 in a reaction buffer solution, and assembling into a DNA octahedron, so as to obtain the DNA octahedron-based intramolecular entropy driving amplifier. The intramolecular entropy driving amplifier can be used for realizing rapid imaging of various lncRNAs. The DNA octahedral structure not only provides abundant sites for the detection of a plurality of lncRNAs, but also integrates all functional modules into a single molecular scaffold. The integration effectively accelerates the reaction kinetics due to the space limiting effect of the DNA octahedron.

1. The name of the design product: emulsion tank (acrylic octahedral type). 2. The use of the design product: a container for holding emulsion. 3. The design points of the design product: in shape. 4. The picture or photo that best indicates the design points: perspective view. 5. The design product is made of transparent material.

This invention relates to the field of mine roadway and traffic tunnel technology. To accurately identify the lithology and weathering degree of rocks within boreholes in real time, it provides a method and device for identifying lithology and weathering degree based on drill rod vibration signals. Based on a six-component vibration sensing architecture with an octahedral structure, it achieves six-component full-dimensional sensing of drill bit rock-breaking vibration acceleration signals. A triple filtering method is used to remove interference, and the vibration frequency is corrected by combining the drill rod length to eliminate the interference of drill rod length changes on the vibration frequency during drilling. The corrected signal is processed by frame segmentation, extracting time-frequency features and time-domain features respectively. Finally, a borehole lithology and weathering degree identification model composed of CNN branches and MLP branches is constructed. The CNN branch automatically learns the local correlation patterns of time-frequency features, and the MLP branch automatically combines the nonlinear relationships in the time-domain features, thereby achieving efficient and accurate identification of borehole lithology and weathering degree.

The application discloses a chromium-doped yttrium oxide crystal material and a structural design method thereof, and belongs to the technical field of inorganic photoelectric functional crystal materials. + The crystal is of R3 trigonal crystal system minimum energy structure, Cr 9‑ The molar doping percentage is 3.125%, occupies a 1b Wyckoff site in a crystal lattice gap, forms [CrO6] 9‑ Regular octahedral coordination, Cr-O bond length is 2.073 angstrom; lattice constants a=b=10.4957 angstrom, c=18.1750 angstrom, a Γ point direct band gap is 3.23 eV, there is no virtual frequency in a phonon spectrum, dynamics is stable, simulated XRD is matched with an experimental spectrum, and Cr-O and Y-O bonds are all ionic bonds. The application realizes accurate determination of a ground state structure, stability verification and electronic property analysis by adopting CALYPSO structure prediction combined with first principle calculation, provides a standardized theoretical design process, and can be used for efficient development of photoelectric functional materials such as solid-state lasers, white light LEDs, solar cells and the like.

The invention discloses a porous curved-surface hollow octadecahedron carbon nanobox material and a preparation method and application thereof, the force balance of a ZIF-67 skeleton structure in heat treatment is adjusted by introducing quantum dots, and the polyhedral morphology of the material can be reserved, so that the material with rich microporous structures and large specific surface area is obtained; the exposure of rich catalytic active sites is facilitated, so that efficient electro-catalysis is realized. The catalyst prepared by the preparation method disclosed by the invention shows excellent bifunctional oxygen catalytic performance. Wherein the overpotential of the OER is only 130 mV when the OER is 10 mA / , and the half-wave potential of the ORR can also reach 0.86 V. According to the scheme, a new strategy is provided for designing a high-efficiency difunctional electrocatalyst, and the development of an air electrode catalyst in a metal-air battery is further promoted.

A method for preparing high dielectric constant, small linewidth yttrium iron garnet ferrite material belongs to the field of ferrite material preparation technology. This invention utilizes the dodecahedral Y-axis in the garnet structure... 3+ octahedral Fe 3+ Instead of using a traditional method, this invention employs a two-stage pre-calcination process and a three-stage ball milling process (low speed followed by high speed), requiring only three ball milling operations, one granulation operation, and one sintering operation to produce yttrium iron garnet ferrite materials. The two-stage pre-calcination process results in better powder activity, a higher degree of solid-state reaction completion during sintering, and superior material properties. The three-stage ball milling process, using a low-speed followed by a high-speed process, enhances the particle size uniformity of the milled powder. The resulting ferrite exhibits a high dielectric constant ε' > 20, a low ferromagnetic resonance linewidth ΔH ≤ 25Oe, and a low dielectric loss tanδ. ε <1×10 ‑4 .

The invention provides a perovskite formation energy prediction method based on a graph neural network and a function subgraph. The method comprises the following steps: firstly, aiming at a perovskite crystal structure, segmenting a crystal diagram into an octahedral sub-diagram taking a B-site atom as a center and a coordination polyhedral sub-diagram taking an A-site atom as a center according to a functional unit for representing a key local coordination environment; secondly, a local dynamic coordinate system is introduced into the functional sub-graph, the relative position between a central atom and a neighborhood atom is projected into a geometric description quantity insensitive to global translation and rotation, and the geometric description quantity, the key length, the key angle and coordination distortion related characteristics are jointly used as the input of a graph neural network; and finally, in a message passing process, fusing edge weight priori of distance and element electronegativity, aggregating information in the sub-graph through an attention mechanism, and finally realizing prediction of perovskite material formation energy. The method is suitable for high-throughput screening and synthesizability evaluation of a large-scale perovskite material library.

This invention discloses a method for optimizing the parameters of composite nano-photosensitizers used in the preparation of photodynamic microneedles, relating to the field of biomedical technology. The method includes: preparing octahedral Cu₂O nanoparticles and recording synthesis parameters; in-situ loading of sheet-like CuTCPP to obtain CuTCPP@Cu₂O composite nanoparticles and recording loading parameters; mixing the composite particles with a first matrix and a natural small molecule with a second matrix, followed by layered casting and vacuum-assisted filling to prepare a bilayer microneedle test sample; evaluating performance and adjusting synthesis and / or loading parameters accordingly; and preparing the composite nano-photosensitizer with the final parameters after achieving the desired performance. This invention solves the technical problem that existing composite nano-photosensitizers lack an iterative optimization mechanism based on microneedle sample performance feedback in parameter determination, making it difficult to ensure that the final product consistently meets the expected functional standards. It achieves precise locking of photosensitizer synthesis and loading parameters, ensuring that the final product possesses the preset performance characteristics.

The application discloses a structure for imparting strain hardening performance to metamaterials and a design method thereof. In the structure for imparting strain hardening performance to metamaterials, unit bodies are periodically arranged in a shared edge mode to obtain an interlaced structure between layers, the structure is deformed from the upper and lower end surface layers, the yield strength of the structure nodes is higher than the yield strength of the deformed layers, the structure is deformed layer by layer, meanwhile, the structure has multiple degrees of freedom of deformation, high tolerance to local strain, high energy absorption, and the generation and expansion of cracks caused by stress concentration are delayed. The mechanical metamaterial prepared by using the photocuring 3D printing technology exhibits the strain hardening characteristics in the compression test, has high specific peak strength (9.6 MPa·cm 3 ·g ‑1 ), specific yield strength (4.3 MPa·cm 3 ·g ‑1 ), specific stiffness (1.26 MPa) and large plasticity (28.2%), and is superior to the octahedral truss lattice structure commonly used in the truss lattice structure under the condition that the materials are the same, the rod diameters and the rod lengths are the same (the rod length-diameter ratio is the same).

A method of preparing bismuth vanadate particles is described. The bismuth vanadate particles prepared via ultrasonication and hydrothermal treatment exhibit controlled morphology (e.g., octahedral shape) and crystallinity (e.g., tetragonal crystal symmetry). A photoelectrode containing bismuth vanadate particles and a method of using the photoelectrode in a photoelectrochemical cell for water splitting is also provided.

The present invention relates to a method for reducing Na loss when preparing a positive electrode active material powder comprising particles having a substantially octahedral shape, the method comprising: mixing a Li source, a precursor comprising a transition metal, and a sintering flux to obtain a mixture; and heating the mixture to obtain a heated material wherein the transition metal comprises Ni, optionally Co and optionally Mn wherein the sintering flux is Na2CO3, and wherein the Na loss is the difference between a first Na content in the mixture and a second Na content in the heated material, the first Na content and the second Na content are measured via ICP-OES and are relative to the total amount of the transition metal.

This invention belongs to the field of silver-manganese composite material preparation, and provides an efficient method for preparing silver-manganese composite materials. The method uses crypto-potassium manganese dioxide or α-MnO2 tunnel nanorods as a framework. After controllable reduction to construct defects, silver species are impregnated and anchored using a silver-ammonia complex solution. Following drying and air fixation treatment, silver-loaded defective manganese oxide octahedral molecular sieves are obtained. In the resulting material, silver can be stably distributed at surface defect sites and / or 2×2 tunnel opening sites, forming Ag-O-Mn interfaces. This method balances interfacial reactivity, pore structure stability, and low migration and long-term stability of silver species, solving the problem of simultaneously achieving high activity and structural stability, and has good application value.

The utility model discloses an assembled and combined type wooden packaging box, and belongs to the field of wooden packaging boxes. Comprising four enclosed rectangular plate bodies, and the plate bodies are mounted together through connecting devices; the connecting device comprises a hinged column and a hinged plate rotationally connected to the hinged column. The connecting device has the advantages that the whole connecting device is made of metal materials, compared with a structure in the prior art, the connecting device is more stable and difficult to use, meanwhile, the external structure of the whole wooden box is not greatly expanded, the size of the occupied space of the wooden box cannot be enlarged, and splicing is very convenient. The connecting device between the plate bodies can provide more choices for the structure of the box body, only the situation when the box body is a cuboid is explained, according to the structure of the connecting device, due to the arrangement of the hinged columns and the hinged plates, single bodies of a triangular body, a hexahedron and an octahedron can be formed, and compared with the prior art, compared with the prior art, the connecting device is convenient to use. And the selectivity of the whole structure of the box body is more.

The invention relates to an Al-Pb nano composite material and a preparation method thereof, and relates to the technical field of nano metal composite materials. According to the main technical scheme, the Al-Pb nano composite material comprises an Al matrix and Pb particles; wherein the Pb particles are embedded in grains of the Al matrix; wherein the Pb particles comprise Pb particles with octahedral structures; the particle size of the octahedral Pb particles is less than 10nm; the volume fraction of octahedral Pb particles in the Pb particles is 65% or more. The particle size and configuration morphology of the Pb particles in the Al-Pb nano composite material are controlled, the lowest interface energy state is achieved, the overheat limit of the nano Pb particles is broken through, the thermal stability of the Al-Pb nano composite material is improved, and a brand new path is opened up for material design and application in an extreme environment.

The application discloses an L-shaped basic piece, an octahedral unit cell configuration and a discrete assembly mechanical superstructure, relates to the technical field of mechanical superstructure, and comprises an L-shaped rod body, the corner of the L-shaped rod body is a right angle, the L-shaped rod body forms a rod body middle part shoulder structure and a rod body end part shoulder structure; and the rod body middle part shoulder structure and the rod body end part shoulder structure corresponding to the six L-shaped rod bodies are connected to form an octahedral unit cell configuration body. A plurality of octahedral unit cell configuration bodies are connected to each other to form a three-dimensional matrix structure by using the octahedral unit cell configuration. According to different connection forms, three different assembly configurations are provided. The discrete unit cell parts can be prepared in large quantities, and the production cost is effectively reduced. The discrete assembly mode further eliminates the limitation of the machining process and the machining size, and solves the problems that the integral forming technology cannot prepare a large-scale lattice superstructure, and the discrete assembly part structure is complex and troublesome to assemble.