26 results about "Dielectric function" patented technology

The invention provides a liquid crystal phase shifter, an antenna device and an antenna system, and relates to the technical field of communication. The liquid crystal phase shifter comprises a first dielectric substrate, a grounding metal layer, a dielectric functional layer, a micro-strip signal line and a second dielectric substrate which are stacked in sequence, the grounding metal layer is provided with a plurality of groups of grid structures which are arranged at intervals, and each group of grid structure comprises a plurality of grids which are distributed at intervals; and the length direction of the micro-strip signal line is parallel to the arrangement direction of the plurality of groups of grid structures. In the embodiment of the invention, the defected ground structure is formed by the plurality of groups of grid structures on the grounding metal layer, so that a relatively wide microstrip signal line can be conveniently arranged, and a relatively thin dielectric functional layer can be arranged under the condition that the characteristic impedance of the liquid crystal phase shifter is ensured, so that the miniaturized liquid crystal phase shifter is realized; in addition, when phase shifting is carried out based on the liquid crystal phase shifter, the thinner dielectric functional layer is convenient for reducing loss and improving response speed, so that the phase shifting performance of the liquid crystal phase shifter is improved.

The invention discloses a terahertz reflectance spectrum-based insulating oil micro-water content and aging detection method, device and equipment and a storage medium, and relates to the technical field of dielectric spectroscopy, and the method comprises the following steps: sampling each standard sample to obtain a to-be-detected sample, placing each to-be-detected sample in a sample bearing vessel to obtain an oil film layer, reflecting terahertz wave beams are utilized to irradiate each oil film layer to obtain a terahertz amplitude spectrum and a terahertz phase spectrum, a target three-layer optical model is utilized to perform inversion to obtain a complex dielectric function frequency spectrum, and a preset sub-dielectric model is utilized to fit the complex dielectric function frequency spectrum to obtain a main resonance characteristic and a characteristic parameter set; determining a reference micro-water content based on the main resonance characteristics, determining training data based on the characteristic parameter set, and constructing a target multi-task regression model; and processing the characteristic parameter set by using the model to obtain an initial prediction result and a confidence interval, verifying the prediction result to obtain a target prediction result, and improving the efficiency of detecting the micro-water content and aging of the insulating oil.

The present disclosure relates to the technical field of communications, and provides a leaky-wave antenna and an antenna system. The leaky-wave antenna comprises: a first dielectric substrate, a first metal layer, a dielectric functional layer, a second metal layer, and a second dielectric substrate. The first metal layer comprises a first transmission line and first radiation units; multiple first notches distributed at intervals are provided on a side edge, parallel to a length direction, on a first plasmon section of the first transmission line; and the multiple first radiation units and the first notches are located on the same side of the first transmission line. In the embodiments of the present disclosure, on the basis of the first plasmon section comprised in the first transmission line, the confinement capability of electromagnetic signals can be enhanced, and the radiation of the electromagnetic signals can be reduced, thereby ensuring the transmission efficiency of the electromagnetic signals, and achieving compact design of leaky-wave antennas. In addition, by radiating antenna signals outward from the first radiation units, high gain of the antenna signals can be ensured while maintaining high transmission efficiency in the first transmission line.

The invention relates to an insulator electric field homogenization and metal particle expelling collaborative optimization method based on an MLB neural network and an NSGA-II, which optimizes the structural parameters of a laminated dielectric functional gradient insulator by constructing a neural network agent model and combining with an NSGA-II multi-target genetic algorithm. Firstly, a neural network model is trained according to sample data, and rapid mapping of input design parameters, output electric field distribution and metal particle motion characteristics is achieved; and then, carrying out global optimization search on the basis of the proxy model, comprehensively considering the targets of the electric field homogenization index and the metal particle flooding efficiency to obtain a Pareto optimal solution set, and screening out a design scheme with the optimal comprehensive performance by using a TOPSIS method. Compared with a uniform insulator, the optimized insulator can realize obvious uniformization of electric field distribution on the concave side and the convex side, and has the capability of actively expelling metal particles, so that surface flashover and particle pollution risks are effectively reduced.

The utility model discloses a composite multimode waveguide structure, which belongs to the technical field of optoelectronic devices and comprises a plasmon unit made of a metal material or a material with a negative real part dielectric function. The plasmon unit is structurally characterized by comprising nanoparticles, nanowires, nanopore arrays or gradient structures; the dielectric waveguide is made of a semiconductor material with a high refractive index, and the dielectric waveguide is designed to be one of a strip-shaped waveguide, a ridge-shaped waveguide or a slit waveguide; and the substrate layer is located below the plasmon unit and the dielectric waveguide and comprises at least one low-refractive-index supporting layer, and the material system of the low-refractive-index supporting layer is one of an oxide material, a nitride material, a fluoride material or a composite substrate structure. According to the scheme, the contradiction of a plasma device and silicon photonics among mode degree of freedom, loss and process compatibility is solved.

The application relates to a method for calculating the optical properties of a thermal control material in the mid-infrared waveband, and belongs to the field of thermal control material design of a spacecraft. The application aims to solve the problem that the existing mainstream calculation ideas are mainly focused on the related calculation in the sunlight waveband, and the calculation and research on the optical properties of the material in the mid-infrared waveband are relatively less. The method comprises the following steps: establishing a unit cell model, optimizing the structure model with high precision through a step-by-step optimization method, calculating a second-order force constant matrix, a BORN effective charge, a dielectric constant tensor, a third-order force constant matrix and a three-phonon scattering rate, determining an optical phonon vibration mode of a Brillouin zone center with infrared activity, calculating the dielectric function of the material according to a Lorentz oscillator model, and further calculating the refractive index and extinction coefficient of the material. The application significantly improves the calculation precision and efficiency of the optical properties of the thermal control material in the mid-infrared waveband, provides a reliable theoretical basis for the research and development of new materials, and can effectively reduce the experimental cost and shorten the research and development period.

This application discloses a lightweight PPO / PA foam material and its preparation method, relating to the field of polymer foam material technology. The method involves constructing a foaming composition using polyphenylene ether, polyamide 6, maleic anhydride-grafted polyphenylene ether, and epoxy-based reactive additives. After mixing and molding, the foam material is obtained through supercritical carbon dioxide saturation foaming and shaping. Further introduction of flame-retardant fillers composed of bisphenol A bis(diphenyl phosphate), melamine cyanurate amide, and zinc borate, as well as SiO2 aerogel or PTFE low-dielectric fillers, can yield flame-retardant, low-dielectric, and flame-retardant low-dielectric foam materials. The beneficial effects of this application are: it can maintain flame-retardant and low-dielectric properties while maintaining low-density mechanical properties, improve foaming stability and cell structure uniformity, enhance the overall structural continuity and comprehensive level of the molded body, and achieve synergy or combination of flame-retardant and low-dielectric functions.

The application discloses a D-type photonic crystal fiber refractive index sensor based on dielectric constant near zero, which comprises a fiber core, the fiber core is a D-type photonic crystal fiber, the cross-sectional shape is composed of an arc and a chord, an open ring channel is arranged in the middle of the chord of the D-type photonic crystal fiber, and an ultrathin conductive oxide film is attached to the inner surface of the open ring channel; the ultrathin conductive oxide has a dielectric function near zero phenomenon in the communication C wave band under a set thickness. The ENZ mode of the ultrathin conductive oxide used in the application can replace the surface plasmon effect of gold in the communication C wave band, and has the advantages of high refractive index sensitivity and low cost.

The invention discloses liquid metal-carbon nano tube doped photosensitive resin and a preparation method and application thereof, and belongs to the technical field of absorption and transmission integrated superstructure materials.The liquid metal-carbon nano tube doped photosensitive resin is prepared by performing functionalization treatment on a multi-wall carbon nano tube through a chemical modification method and introducing liquid metal which is a dielectric functional group. And the electromagnetic parameters of the multi-walled carbon nanotubes are regulated and controlled. And doping the liquid metal loaded carbon nano tube into the modified photopolymerization resin to obtain the liquid metal-carbon nano tube doped photosensitive resin. According to the invention, a chemical modification method is adopted to carry out functionalization treatment on the multi-walled carbon nanotube, and electromagnetic parameters, namely a real part and an imaginary part of a dielectric constant, are adjusted by introducing a liquid metal eutectic gallium-indium alloy which is a dielectric functional group. Functionalized carbon nanotubes, namely liquid metal loaded carbon nanotubes, are doped into a polyether acrylate photocuring matrix, namely modified photopolymerization resin, so that the electromagnetic performance of the material is accurately regulated and controlled.

The application discloses a liquid metal-carbon nanotube doped photosensitive resin and a preparation method and application thereof, and belongs to the technical field of absorption-transmission integrated superstructure materials. The multi-walled carbon nanotubes are functionally treated by adopting a chemical modification method, and the electromagnetic parameters of the multi-walled carbon nanotubes are regulated by introducing a liquid metal dielectric functional group. The liquid metal-loaded carbon nanotubes are doped in the modified photopolymerization resin to obtain the liquid metal-carbon nanotube doped photosensitive resin. The multi-walled carbon nanotubes are functionally treated by adopting a chemical modification method, and the electromagnetic parameters, i.e. the real part and the imaginary part of the dielectric constant, are regulated by introducing a liquid metal eutectic gallium-indium alloy dielectric functional group. The functionalized carbon nanotubes, i.e. the liquid metal-loaded carbon nanotubes, are doped in a polyether acrylate photocuring matrix, i.e. the modified photopolymerization resin, to realize accurate regulation of the electromagnetic performance of the material.

The invention relates to a glass tube, a preparation method of the glass tube and application of the glass tube in an intelligent sensor, belongs to the technical field of preparation of sensor glass tubes, and aims at solving the problems that a traditional glass tube is insufficient in dielectric property, poor in thermal expansion characteristic adaptability, prone to environmental erosion and the like. The modified barium strontium silicate is prepared through the steps of raw material pretreatment, stepped heating calcination, surface modification and the like, the glass tube is prepared through raw material mixing, high-temperature melting, forming and processing treatment, and the glass tube can be applied to the fields of reed switch sensor packaging, liquid level measurement transparent elements, anti-theft sensor triggering structures and the like. The modified barium strontium silicate is introduced to construct a dielectric functional unit, so that the fidelity of high-frequency signals is optimized, the long-term environmental stability and the structural integrity under thermal shock are improved, and the application in high-end intelligent sensors can be expanded.

The invention provides a band-pass phase shifter and an antenna device, and relates to the technical field of communication. The band-pass phase shifter comprises a first dielectric substrate, a first metal layer, a dielectric function layer, a second metal layer and a second dielectric substrate, the second metal layer comprises a filtering transmission line, the filtering transmission line comprises a pair of dual composite transmission lines, each dual composite transmission line comprises an interdigital capacitor and an electric transmission line, and the interdigital capacitor is connected with the dielectric function layer. Coupling feeding is formed between the electric transmission lines included in the pair of dual composite transmission lines. In the embodiment of the invention, for the dual composite transmission lines included in the filtering transmission line, the filtering characteristic of a certain bandwidth can be realized through the coupling arrangement of a pair of dual composite transmission lines based on the band elimination characteristic of the dual composite transmission lines; meanwhile, based on the arrangement of the dielectric functional layer, the adjustment of the electromagnetic wave phase can be realized by adjusting the dielectric constant of the dielectric functional layer; therefore, while the miniaturization design of the band-pass phase shifter is realized, the phase shifting characteristic and the filtering characteristic of the band-pass phase shifter are ensured.

The invention discloses a preparation method of a low-dielectric functional additive for an immersed electronic cooling liquid. The method comprises the following steps: (1) drying low-dielectric cavity type molecules under reduced pressure to remove moisture, and drying for later use; (2) respectively carrying out alkylation modification, silanization modification and fluorination modification on the dried low-dielectric cavity type molecules in an inert solvent to prepare an alkyl modified low-dielectric auxiliary agent, a silane modified low-dielectric auxiliary agent and a fluorination modified low-dielectric auxiliary agent; and (3) dissolving and matching the prepared low-dielectric auxiliary agent with a conventional cooling liquid to prepare the low-dielectric immersed cooling liquid. In conclusion, the low-dielectric functional additive for the immersed electronic cooling liquid has the advantages of capability of remarkably reducing the dielectric constant of the cooling liquid, high compatibility, wide applicability, good stability and the like, can solve the industrial common problem that the dielectric constant of the current conventional cooling liquid is relatively high, and has a wide application prospect in the fields of immersed chip heat exchange and the like.

Disclosed herein is a method for detecting at least one binding event of a specific binding pair-forming substance, comprising: providing a layer (2) of a first specific binding pair-forming substance on a substrate (3), the specific binding pair-forming substance having a density of 102-104 / [mu] m2 of the substrate (3). Providing a housing (4) of the first specific binding pair-forming substance layer (2) having a first dielectric comprising a first solution having a first pH value and a first ionic strength value, rinsing the housing (4) with a second dielectric comprising a second solution having a second pH value and a second ionic strength value for a first period of time, wherein at least the second pH value is different from the first pH value,-after the rinsing, recovering the first dielectric having a first pH value and a first ionic strength value in the housing (4),-feeding a solution of a second specific binding pair-forming substance into the housing (4) of the layer (2) of the first specific binding pair-forming substance, after the recovery of the first dielectric in the shell (4), causing an interaction between the first specific binding pair-forming substance and a second specific binding pair-forming substance, and culturing the shell (4) for a second period of time, the interaction comprises a binding event when the first specific binding pair forming substance and the second specific binding pair forming substance provide said specific binding pair,-detecting an offset ([Delta] [Theta]) of a parameter ([Theta]) representative of a dielectric function of the layer (2) of the first specific binding pair forming substance after said incubation shell (4) lasts for a second period of time, the offset is defined as a change in a parameter ([theta]) representing a dielectric function of a first specific binding pair forming a layer (2) of a substance from a first value occurring when the housing (4) comprises only the first dielectric after the recovery of the first dielectric to a second value occurring after the incubation of the housing (4) for a second period of time, -comparing the offset ([delta] [theta]) with a threshold value, whereby when the offset exceeds the threshold value, at least one binding event occurs between said first and second specific binding pair-forming substances.

The application discloses a controllable gradient material preparation device and method based on dielectrophoresis. A vacuumizing device is communicated with the inner cavity of an oven, and an experimental platform is arranged in the inner cavity of the oven. The experimental platform comprises a bottom plate mold and a pressurizing layer mold. The pressurizing layer mold has a pouring cavity, and the bottom plate mold is arranged at the bottom of the pressurizing layer mold and blocks the bottom of the pouring cavity. Two pairs of electrodes for simulating the electric field environment of the dielectric functional gradient material under actual working conditions are arranged in the pouring cavity of the pressurizing layer mold in a height direction. The outlet of a solution supply generator is arranged above the pouring cavity of the pressurizing layer mold, the solution supply generator is used for pouring a composite solution into the pouring cavity of the pressurizing layer mold, and a controllable voltage source is connected with all the electrodes. The application can improve the dielectric constant distribution of the material, adapt to complex electric fields in multi-dimensional space, reduce internal defects of the polymer material and improve the dielectric and electrical properties of the insulating material.

The invention provides an analysis method of a zinc sulfide optical window surface oxide layer, which comprises the following steps: firstly obtaining the spectrum and thickness of a window without an oxide layer to accurately calibrate the intrinsic dielectric function of a zinc sulfide substrate, then establishing an optical physical model containing the surface oxide layer, and taking the test spectrum of the optical physical model with the oxide layer as a target to accurately calibrate the intrinsic dielectric function of the zinc sulfide substrate. And the physical thickness and the dielectric function of the surface oxide layer are inverted through fitting calculation at the same time. According to the method, non-destructive, synchronous and accurate measurement of the thickness and the optical constants (the refractive index and the extinction coefficient) of the surface oxide layer of the zinc sulfide optical window is realized for the first time, and the technical problem that the surface oxide layer characteristics are difficult to quantitatively analyze in special application environments such as high temperature is effectively solved; key data support is provided for accurately evaluating the window performance, predicting the service life of the window and developing efficient anti-oxidation measures, and the reliability and application development of the zinc sulfide optical window technology are remarkably promoted.

The invention provides a leaky-wave antenna and an antenna system, and relates to the technical field of communication. The leaky-wave antenna comprises a first dielectric substrate, a first metal layer, a dielectric functional layer, a second metal layer and a second dielectric substrate, the first metal layer comprises a first transmission line and first radiation units, a plurality of first notches distributed at intervals are formed in the edge of one side, parallel to the length direction, of a first plasmon section of the first transmission line, and the first radiation units and the first notches are located on the same side of the first transmission line. According to the leaky-wave antenna, based on the first plasmon segment included in the first transmission line, the binding capacity of an electromagnetic signal can be improved, radiation of the electromagnetic signal can be reduced, and therefore the transmission efficiency of the electromagnetic signal can be guaranteed, and meanwhile small-size arrangement of the leaky-wave antenna can be conveniently achieved; besides, the first radiation unit radiates the antenna signal outwards, so that the high gain of the antenna signal can be ensured on the basis that the first transmission line has relatively high transmission efficiency.

The invention belongs to the technical field of far infrared refractive index detectors, and particularly relates to a far infrared refractive index detector based on a thin metasurface and a preparation method of the far infrared refractive index detector. The method comprises the following steps: providing a polar dielectric substrate and a high-refractive-index material, obtaining dielectric functions of the polar dielectric substrate and the high-refractive-index material through an ellipsometry test, performing full-wave numerical simulation by taking the obtained parameters as input, constructing a metasurface physical model, testing transmissivity and complex refractive index of a medium to be tested, and assembling a PMMA micro-channel, the metasurface and the medium to be tested into an integrated device to carry out joint test. And finally, the reflection spectrum of the assembly device in the far infrared band is obtained through an ellipsometry test. According to the invention, through a novel material model and model optimization, comprehensive performances of insensitivity of an incidence angle of a far infrared band, high narrow-band absorption, strong near field and high penetration depth are realized; therefore, the problems of strong incidence angle dependence, insensitivity to volume phase response, easy surface pollution / adsorption interference, high device size and complexity, low detection efficiency and the like in the traditional technology are effectively solved.

The invention relates to an insulating operating rod body and a preparation method thereof, and belongs to the technical field of electric power safety tools and instruments and high-performance composite materials, the insulating operating rod body comprises a bearing core layer which is formed by an integrally-formed aramid fiber prefabricated body of a three-dimensional angle interlocking braided structure; the dielectric functional layer is a hydrophobic nano-porous silicon dioxide aerogel continuous network which is filled and fixed in internal pores of the aramid fiber preform of the bearing core layer, and silicon dioxide aerogel and aramid fibers are interwoven to form a three-dimensional interpenetrating structure; and the functional gradient protective layer is a resin-based composite material layer coated outside the dielectric functional layer. Three-dimensional weaving, nano-porous aerogel and gradient resin technologies are combined, the mechanical strength, the interface performance, the electrical insulating property and the weather resistance of the rod body are synergistically improved, unification of light weight and high reliability is achieved, and the rod body is particularly suitable for high-voltage and extra-high-voltage live working.

The invention provides a phase shifter, an antenna device and an antenna system, and relates to the technical field of communication. The phase shifter comprises a first substrate, a second substrate and a dielectric functional layer, the first substrate comprises a first dielectric layer, a first metal layer and a second metal layer, the first dielectric layer is provided with a through hole, the first metal layer is provided with a hollow area for exposing the through hole, and the second metal layer is located in an accommodating area; the second substrate comprises a second dielectric layer and a third metal layer, and the third metal layer is located on the side close to the first substrate. The phase shifter further comprises a feeder line located in the through hole, and the first end of the feeder line is connected with the second metal layer. According to the phase shifter, the through hole is formed in the position, corresponding to the containing area, of the first dielectric layer, and then connection with the second metal layer in the containing area is achieved through the feeder line in the through hole, so that the feeder line is simplified, the transmission path of a radio frequency signal is shortened, the structure of the phase shifter is simplified, the miniaturization design of the phase shifter is achieved, and the cost of the phase shifter is reduced. And efficient integration of the phase shifter is facilitated.

The invention discloses a flexible dielectric tuning film with low loss and high tuning performance and a preparation method thereof, and relates to the technical field of flexible electronic and dielectric functional materials. Through a technical route of modification of a dielectric filler by a silane coupling agent, optimization of a composite dispersion process and stepped drying annealing, the technical problem that tunability-loss-flexibility of an existing dielectric tuning film cannot be synergistically optimized is effectively solved. The dielectric loss of the film under 1kHz is less than 0.008, the tuning rate under 50kV / cm is greater than 40%, the elongation at break is greater than 30%, the performance degradation after 1000 times of bending circulation is less than 8%, and the film has excellent environment and temperature stability and can be widely applied to the fields of flexible microwave communication, phased array radar, wearable electronics and the like.

The application relates to a packaging method under an ellipsometric spectrum and a metal dielectric function measurement method. A packaging material is used to package a material to be measured. A thickness relationship formula one, a relationship formula two and a relationship formula three are used to obtain a minimum d value of z2 and z1, z3 light spot area separation. The minimum d value is used for packaging, which can enhance the accuracy of the detection data of a detector. Then, a final packaging thickness is obtained by combining an error allowable range, and the accuracy of the metal dielectric function is improved.

The invention belongs to the field of low-dielectric functional composite materials, and particularly relates to a low-dielectric-constant hydrophobic anti-icing prepreg, a preparation method and a composite material component. According to the prepreg, low-dielectric resin serves as a matrix, reinforced fibers and hydrophobic components in gradient distribution are compounded, the low-dielectric characteristic that the dielectric constant is smaller than or equal to 3.0 (10 GHz) is kept, the synergistic effect that a surface layer efficiently prevents and removes ice and an inner layer guarantees mechanical and dielectric properties is achieved through gradient distribution of the hydrophobic components, and the preparation method has the advantages that through distributed gum dipping and special-shaped compression roller regulation and control; the coating is suitable for high-frequency communication components which need excellent low dielectric properties and need anti-icing and deicing functions, and the problems that a traditional anti-icing and deicing coating is poor in compatibility with a low dielectric substrate and the dielectric properties are interfered are solved.

The invention discloses an organic-inorganic hybrid reversible phase change material as well as a preparation method and application thereof, and belongs to the field of functional materials. According to the organic-inorganic hybrid reversible phase change material, N, N, N-trimethyl isopropylamine and a halogen substituted derivative thereof are used as organic cations, an iron halide anion [FeX] (X = Cl, Br) with a tetrahedral configuration is used as an inorganic anion, and a molecular crystal is prepared through a solution evaporation method. The material is subjected to reversible solid-solid phase change in a mild temperature range (about 330-356 K) close to the working temperature of a device, and is obviously changed along with the dielectric constant in a phase change temperature region. The phase change temperature and the dielectric response behavior can be adjusted by cooperatively regulating and controlling the structure of the organic cation and the type of the inorganic halogen complex anion. The material is mild in preparation method, is suitable for amplification and film processing, and can be used for a dielectric regulation and control structure, a reconfigurable dielectric unit and a packaging layer dielectric function module.

The invention provides a method and a system for non-contact inversion of semiconductor carrier concentration based on Fourier infrared transform spectrum. Aiming at the problems that a traditional electrical detection method, such as a Hall effect, needs device preparation and causes inevitable damage to a to-be-detected sample, the invention develops a non-contact inversion semiconductor carrier concentration measurement method based on a Fourier transform infrared spectroscopy FTIR technology and in combination with a Deroude Diode model. Acquiring transmission / reflection spectrum data of the semiconductor sample by using an FTIR spectrometer; secondly, according to an optical response behavior of a free carrier in a semiconductor, adopting a classical Dyde dielectric function model, and further fitting an experimental spectrum to obtain a plasma frequency, a line width, a background dielectric constant and the like in a dielectric function of the sample; and finally, calculating a carrier concentration value in combination with parameters such as the effective mass of the carrier. The method disclosed by the invention has the advantages of no contact, no damage, rapidness and wide application concentration range.

The present application belongs to the technical field of synthesis of all-organic polymer dielectric film, and particularly relates to a copolymerized polyamide with dielectric function containing nylon 1 chain segment and a preparation method, the preparation method of the dielectric polyamide film containing nylon 1 chain segment comprising the following steps: synthesis of nylon 1 with different polymerization degrees, butane diacid anhydride end-capping nylon 1, and salt formation of the end-capped product (referred to as "PA1 diacid") and piperazine, copolycondensation reaction of piperazine-PA1 diacid salt and piperazine-dodecanedioic acid salt, and hot-pressing forming, etc. In the present application, the piperazine-PA1 diacid salt and the piperazine-dodecanedioic acid salt are copolycondensed through high temperature and high pressure, the high dielectric constant of the nylon 1 chain segment is combined with the unique low dielectric loss of the piperazine nylon, the nylon 1 is embedded into the piperazine nylon matrix as a dielectric function chain segment, and the dielectric polyamide film containing the nylon 1 chain segment is directly prepared through simple hot-pressing forming.