64results about How to "High mechanical hardness" patented technology

The invention provides a double-layer conductive thin film-based transparent broadband electromagnetic wave absorber and aims at solving the technical problem of a narrow application range of an existing wave absorber. The double-layer conductive thin film-based transparent broadband electromagnetic wave absorber comprises a conductive thin film, a first dielectric layer, a second dielectric layer, a third dielectric layer and a bottom plate, wherein transparent dielectric plates are adopted as the first dielectric layer and the third dielectric layer; the transparent dielectric plate or an air dielectric is adopted as the second dielectric layer; the three dielectric layers are arranged from top to bottom to form the dielectric layers with a stacked structure; a transparent conductive thin film is adopted as the bottom plate and is printed on the lower surface of the third dielectric layer; and the conductive film is formed by compounding m*n arrays formed by square transparent conductive thin films and (m+1)*(n+1) arrays formed by cross-shaped transparent conductive thin films and is printed on the upper surface of the first dielectric layer. High light transmission is achieved while the wave absorption bandwidth and the wave absorption rate are ensured; and the double-layer conductive thin film-based transparent broadband electromagnetic wave absorber can be applied to electromagnetic anti-interference of microwave systems, of aircraft cabin glass, a PCB-based novel inter-chip wireless interconnection system and the like, requiring the high light transmission.

The invention provides a compound cesium fluoborate, a nonlinear optical crystal with the cesium fluoborate, methods for preparing the compound cesium fluoborate and the nonlinear optical crystal and application of the compound cesium fluoborate and the nonlinear optical crystal. A chemical formula of the compound is CsB<4>O<6>F, the molecular weight of the compound is 291.15, and the compound is of a crystal structure and is prepared by the aid of solid-phase synthesis processes or vacuum packaging processes. A chemical formula of the nonlinear optical crystal is CsB<4>O<6>F, the molecular weight of the nonlinear optical crystal is 291.15, the nonlinear optical crystal belongs to orthorhombic crystal systems, space groups of the nonlinear optical crystal are Pna2<1>, crystal cell parameters of the nonlinear optical crystal include that an a is equal to 7.9241 , a b is equal to 11.3996 , a c is equal to 6.6638 and an alpha, a beta and a gamma are equal to 90 degrees, and the unit cell volumes of the nonlinear optical crystal are 601.95 <3>. Frequency doubling effects of the nonlinear optical crystal is approximately two times frequency doubling effects of KH<2>PO<4> [KDP (potassium dihydrogen phosphate)], and ultrasonic absorption edges of the nonlinear optical crystal are shorter than 190 nm. The nonlinear optical crystal is grown from the CsB<4>O<6>F by the aid of melt processes, high-temperature solution processes, vacuum packaging processes, hydrothermal processes or room-temperature solution processes. The compound cesium fluoborate, the nonlinear optical crystal, the methods and the application have the advantages that the nonlinear optical crystal is free of deliquescence in air, is good in chemical stability and can be applied to all-solid-state laser devices as an ultraviolet nonlinear optical crystal or deep ultraviolet nonlinear optical crystal.

The invention provides compound caesium potassium fluoborate and caesium potassium fluoborate non-linear optic crystal, and a preparation method and applications thereof. The chemical formula of the compound is CsKB8O12F2, the molecular weight is 488.48, and the compound is prepared via solid phase synthesis or vacuum packaging method. The chemical formula of the caesium potassium fluoborate non-linear optic crystal is CsKB8O12F2, the molecular weight is 488.48, the caesium potassium fluoborate non-linear optic crystal belongs to trigonal system, the space group is P321, the cell parameters a=b=6.598 angstroms, c=7.652 angstroms, alpha=beta=90 DEG, gamma=120 DEG, unit-cell volume is 288.5 angstroms, the frequency-doubled effect is about 2 times of that of KH2PO4(KDP), the UV absorption edge ranges from 150 to 200nm. Crystal growth of CsKB8O12F2 is realized via high temperature molten method, vacuum packaging method, hydrothermal method, or room temperature solution method; deliquescence of the crystal is not caused in the air; the chemical stability is excellent; and the crystal can be used in all-solid-state lasers as an ultraviolet, deep ultraviolet non-linear optic crystal.

The invention provides a compound caesium rubidium fluorborate, a caesium rubidium fluorborate nonlinear optical crystal, a preparation method and application. The compound has a chemical formula of CsRbB8O12F2 and a molecular weight of 534.86, and is prepared by solid phase synthesis or vacuum encapsulation method. The crystal has a chemical formula of CsRbB8O12F2 and a molecular weight of 534.86, belongs to hexagonal crystal system, has a space group of P-62c, the cell parameters of a=b=6.5878 angstrom, c=7.813 angstrom, alpha=beta=90 degrees, gamma=120 degrees, and a unit cell volume of 293.6 angstrom<3>. The frequency-doubled effect of the crystal is 2 times that of KH2PO4(KDP), and the ultraviolet absorption edge is 150-200nm. CsRbB8O12F2 adopts high temperature melt liquid method, vacuum encapsulation method, hydrothermal method or room temperature solution method for crystal growth, the crystal has the advantages of no deliquescence in the air and good chemical stability, and can be applied as ultraviolet and deep ultraviolet nonlinear optical crystal in all-solid-state lasers.

The invention discloses a sludge aerobic composting method. The method disclosed by the invention is a method for carrying out sludge aerobic composting by taking afforest wastes (such as branch sections) as a conditioner, and comprises the following steps: (1) mixing sludge and the afforest wastes according to a mass ratio of (2-4):1, specially 3:1, so as to obtain a mixture; and (2) composting the mixture obtained in the step (1) and monitoring the temperature of a pile body in the composting process; in the composting process, turning for one time when the temperature of the pile body is more than 60 DEG C; finishing the composting after a plurality of times of turning and when the temperature of the pile body is reduced to be lower than 30 DEG C and is not raised. According to the sludge aerobic composting method, the high-temperature aerobic composting of organic wastes is used as the basis and the afforest wastes are used as the conditioner to treat the municipal sludge so as to consume a large amount of the afforest wastes while the harmlessness and the reclamation of the sludge are realized, so that the two aims can be realized by one action. Visibly, the sludge aerobic composting method has a wide application prospect.

The invention discloses a magnesium-modified globular calcium-based thermochemical energy storage material and a preparation method thereof. The preparation method comprises the following steps: weighing a calcium source precursor and a stabilizer magnesium source precursor according to a certain ratio, grinding for uniform mixing, and calcining the mixture in an air atmosphere to obtain a calciumoxide and magnesium oxide mixed powder; adding an organic carbon source, performing mixing for uniformity, and carbonizing the obtained material at a constant temperature in an inert atmosphere to obtain a fluffy black solid with a carbon template; cooling the carbonized black solid to room temperature, adding a proper amount of deionized water, placing the solid and the water in an extruder, extruding out a strip-shaped solid, and processing the strip-shaped solid in a ball rolling machine to prepare spherical particles; and calcining the spherical particles in the air atmosphere to obtain the magnesium-modified globular calcium-based thermochemical energy storage material. The thermochemical energy storage material prepared in the invention has the advantages of long-term stability andefficient energy storage capacity, and the preparation method has the advantages of simplicity, easiness in operation, nontoxicity and easy large-scale obtaining of the raw materials, and strong practicability.

The invention relates to a compound strontium fluoborate and a strontium fluoborate nonlinear optical crystal, and preparation methods and uses thereof. The chemical formula of the compound is SrB5O7F3, the molecular weight is 310.67, and the compound is prepared by a solid phase reaction technology; and the chemical formula of the crystal is SrB5O7F3, the molecular weight is 310.67, the crystal belongs to an orthorhombic system, the space group is Ccm21, and cell parameters are as follows: a = 1.0016(6) nm, b = 0.8654(6) (4) nm, c = 0.8103(5) nm, Z = 4, and V = 0.7024(8) nm<3>. The inventionalso discloses the use of the SrB5O7F3 nonlinear optical crystal with the size being in the centimeter grade through the preparation method in the preparation of harmonic wave light output with the frequency being 2 or 3 or 4 or 5 or 6 times the frequency of 1064 nm fundamental frequency lights output by a Nd:YAG laser device or 200 nm or less deep ultraviolet frequency-doubled light output, or the use in the preparation of a frequency multiplier generator, an frequency up-converter or a frequency down-converter, or an optical parametric oscillator. The SrB5O7F3 nonlinear optical crystal has the advantages of wide light transmission band, stable physical and chemical properties, large mechanical hardness, no fragmentation or deliquescence, and easiness in cut, polishing processing and preserving.

An electrochromic layer structure with at least one active layer (100) and at least two electrodes (102; 104) is described. At least one of the electrodes (102; 104) has an electrically conductive network (110; 202) of conductor tracks and the conductor tracks contain nanoparticles (300). An electrochromic device, a method for production of an electrochromic layer structure and use of an electrochromic layer structure and an electrochromic device are also described.

A perpendicular magnetic recording disk has a granular cobalt alloy recording layer (RL) containing on the “soft” magnetic underlayer (SUL). The SUL is doped with judiciously chosen elements or alloys or is capped or intercalated with said elements or metal alloy layers. The resulting disk and the SUL in particular has good recording properties, improved mechanical strength and improved corrosion resistance over a comparable disk without the doping or thin layers.

A disc device has a plurality of arms configured to support the outer rim of a disc carryable. Automatic loading is applied such that the disc inserted can be carried in the device, and the disc housed inside the device can be carried out of the device. A pair of shutter pieces are located on the central portion of a slot in a front bezel to be used to insert the disc therethrough and are spaced at a certain interval. The shutter piece rotates about one end thereof to raise / tumble the other end thereof. The tumbled shutter piece changes to the raised state after the disc is housed in the device while the shutter piece changes to the tumbled state before the disc housed inside the device is carried out of the device.

The invention relates to a three-dimensional, ceramic component containing silicon carbide, to a method for producing the component, and to the use of the component. The method for producing a three-dimensional, ceramic component containing silicon carbide comprises the following steps: a) providing a powdery composition having a grain size (d50) between 3 microns and 500 microns and comprising atleast 50 wt% of coke, b) providing a liquid binder, c) depositing a layer of the material provided in a) in a planar manner and locally depositing drops of the material provided in b) onto said layerand repeating step c), wherein the local depositing of the drops in the subsequent repetitions of said step is adapted in accordance with the desired shape of the component to be produced, d) at least partially curing or drying the binder and obtaining a green body having the desired shape of the component, e) carbonizing the green body, and f) siliconizing the carbonized green body by infiltration with liquid silicon, wherein the green body, while above the melting temperature of silicon and while located substantially above the surface of a silicon bath, becomes saturated with silicon by capillary forces.

The invention belongs to the technical field of lithium ion batteries and particularly relates to a lithium ion battery package casing. The lithium ion battery package casing is of a two-layer structure, wherein an outer layer of the lithium ion battery package casing is a vacuum-deposited metal layer; and an inner layer of the lithium ion battery package casing is a plastic structure layer. Compared with the prior art, the lithium ion battery package casing disclosed by the invention has the characteristics of high strength, lightness, thinness and low possibility of leaking electrolyte, and can meet special requirements of various kinds of portable equipment for the shape of the battery. Meanwhile, the vacuum-deposited metal layer as the outer layer can also be directly used as a casing of the portable equipment without being additionally processed, so that the production cost is saved. In addition, the invention further discloses a lithium ion battery containing the package casing as well as a power supply adopting the lithium ion battery for the portable equipment.

The invention relates to an optical-cable-embedded composite type leaky coaxial cable and a manufacturing method of the optical-cable-embedded composite type leaky coaxial cable. Compared with a single leaky coaxial cable product, all the advantages of the performance of the leaky coaxial cable are achieved, and the advantages of the performance of an optical cable are added. The optical-cable-embedded composite type leaky coaxial cable is characterized by comprising an optical cable, a bundling line copper tube, a polyethylene foamed insulation layer, a slotted copper strip and an outer polyolefin sheath; the optical cable is wrapped in the bundling line copper tube, the polyethylene foamed insulation layer is extruded on the outer portion of the bundling line copper tube in a protection mode, the slotted copper strip wraps the outer face of the polyethylene foamed insulation layer, and the outer polyolefin sheath is arranged on the outer face of the slotted copper strip in an extrusion molding mode. According to the optical-cable-embedded composite type leaky coaxial cable, a composite structure is formed by embedding the optical cable and conducting reasonable combination, it is ensured that the cable has the electrical performance of the leaky coaxial cable, the electrical performance of the optical cable is added, and the optical-cable-embedded composite type leaky coaxial cable is a novel multi-functional type product.

The invention discloses a zinc alloy material. The zinc alloy material is prepared from, by mass, 5.2%-8.25% of iron, 1.25%-2.1% of copper, 1.15%-1.4% of nickel, 0.32%-0.52% of tungsten, 0.12%-0.23% of ruthenium, 0.06%-0.09% of vanadium, 0.23%-0.39% of cobalt, 0.02%-0.06% of beryllium and the balance zinc. The invention further discloses a preparation method of the alloy material. The zinc alloy material is high in mechanical hardness, good in abrasion-resisting effect, extremely excellent in tenacity and extremely suitable for certain mechanical parts having special requirements for the mechanical performance; the zinc alloy material is light, low in cost and quite suitable for application and popularization.

The invention discloses a broadband coplanar waveguide semi-elliptical slot antenna array structure in millimeter wave antenna level packaging, relates to the technical field of antenna arrays, and solves the problem of how to design an antenna array which is large in array bandwidth, high in gain, easy to integrate and suitable for a narrow, long and straight scene. The antenna comprises an antenna array radiation assembly, an antenna array feed assembly and a GCPW-to-CPW transition structure. The antenna array feed assembly excites a corresponding antenna unit through a GCPW-to-CPW transition structure and a rectangular CPW feed line. The antenna unit comprises an etched semi-elliptical gap of a first metal grounding plate on the upper surface of a microwave dielectric substrate and an open-circuit fan-shaped branch knot. The semi-elliptical gap is a gap etched by the fan-shaped outer edge of the fan-shaped branch knot and the first metal grounding plate; the distance between the midpoint of the chord corresponding to the fan-shaped arc of the open-circuit fan-shaped branch knot and the surrounding first metal grounding plate is gradually changed according to a semi-ellipse, andcompared with a traditional circular and elliptical slot structure, the slot width is reduced, the array radiation effect is improved, and the array bandwidth and gain are larger.

The invention relates to a compound Pb0.78Ba8.22B18O36, a Pb0.78Ba8.22B18O36 nonlinear optical crystal, preparation methods and an application and belongs to the technical field of nonlinear optical crystals. According to the technical scheme, the chemical formula is Pb0.78Ba8.22B18O36, the molecular weight is 2060.84, the crystal belongs to a hexagonal crystal system and a space group R32, for lattice parameters, a is equal to 7.2225(2) angstrom, c is equal to 19.2716(10) angstrom, Z is equal to 1 and V is equal to 870.61(6) angstrom<3>; the frequency-doubling effect of powder of the crystal reaches 1 / 3 times of KDP (potassium dihydrogen phosphate), and the light transmitting waveband is 310 nm-2,600 nm. The compound Pb0.78Ba8.22B18O36 and the Pb0.78Ba8.22B18O36 nonlinear optical crystal have the positive effects as follows: the compound is synthesized with a solid phase reaction method, the crystal growth is realized with a co-solvent method, and the crystal has the advantages of simplicity in operation, low cost, large size, short growth period, a few inclusions, higher mechanical hardness and easiness in cutting, polishing processing and storage; the Pb0.78Ba8.22B18O36 nonlinear optical crystal can be widely applied to frequency-doubling conversion as well as nonlinear optical devices such as an optical parametric oscillator and the like.

The invention relates to a guanidine tetrafluoroborate nonlinear optical crystal and a preparation method and application thereof. The chemical formula of the crystal is [C (NH2) 3] BF4, the molecular weight is 146.89, the crystal belongs to a trigonal system, the space group is R3m, and the cell parameters are as follows: a = 7.4634 (10) angstroms, b = 7.4634 (10) angstroms, c = 9.1216 (19) (6) angstroms and Z = 3. The ultraviolet cut-off edge is 200 nm, the frequency doubling response is 4-5 times that of a commercial nonlinear optical crystal KDP, and the crystal with the centimeter-level size is grown by adopting a hydrothermal method, a room-temperature solution method, an evaporation method or a solvothermal method; the invention relates to the application of the crystal for preparing harmonic light output with frequency doubled or frequency tripled or frequency quadrupled or frequency quintupled or frequency sextupled of 1064 nm fundamental frequency light outputted by an Nd: YAG laser, or generating ultraviolet and deep ultraviolet frequency doubled light output lower than 200 nm, or for preparing a frequency doubled generator, an upper or lower frequency converter or an optical parametric oscillator. The crystal has the advantages of wide light-transmitting wave band, stable physical and chemical properties, high mechanical hardness, difficulty in fragmentation and deliquescence, easiness in cutting, polishing, processing and storage and the like, and has important application in the fields of optics, laser lithography and communication.

The invention provides a magnetic circuit structure of a washer variable frequency DC motor, and relates to the technical field of washers. The magnetic circuit structure of the washer variable frequency DC motor comprises a stator iron core, magnetic shoes are arranged on the outer circumference of the stator iron core, and a magnetic yoke is arranged outside the magnetic shoes. The magnetic circuit structure of the washer variable frequency DC motor is characterized in that an N pole and an S pole are formed in the same magnetic shoe through magnetic steel magnetizing, the magnetic shoes are circumferentially and evenly distributed on the magnetic yoke so that each pair of N pole and S pole can deflect relative to the angle of the circle center, harmonic waves of 2p and the multiple of 2p are weakened, the efficiency of the motor is improved, and meanwhile the processing technology is simplified. Twelve magnetic shoes are evenly distributed on the magnetic yoke to form a motor with 12 pairs of poles, and cogging torque can also be weakened. The entire machine working noise caused by torque fluctuation is reduced, meanwhile, the motor can achieve higher torque density, the mechanical hardness of the motor is improved, and revolution drop caused by incremental loading of the motor is reduced. Meanwhile, the system response speed is increased under the condition of the same loads, the acceleration time can be shortened, and the unit eddy-current loss of the stator iron core of the motor can further be reduced.

In this layer, the Ti:N, Ti:C:N sublayer is formed on the etched Ti substrate, and DLC is coated, and afterwards, the proportion of the sp2 carbon structure and the sp3 carbon structure is changed to lower the surface specific resistance, and by having electrochemical traits, the trait of enhancing the adhesion of the Ti substrate and the DLC layer is caused to have high durability and electrochemical traits, providing wide-area water-treatment DLC / Ti electrode manufacture method.

The invention relates to a lead barium borate compound and a lead barium borate nonlinear optical crystal and a preparation method and application, and belongs to the technical field of nonlinear optical crystals. According to the technical scheme, the chemical formula of the crystal is Pb0.81Ba8.19B18O36, the molecular weight is 2063.14, the crystal belongs to a hexagonal system, the space group is R32, cell parameters are that a=7.2116(7) angstroms, c=19.226(4) angstroms, Z=1, V=865.9(2) cubic angstroms, the powder frequency-doubling effect reaches one third time that of KDP, the transparency range is wider, and the transparency wave band ranges from 310 nm to 2600 nm. The lead barium borate compound and the lead barium borate nonlinear optical crystal and the preparation method and application have the advantage that the compound is synthesized through a solid phase reaction method, the crystal is grown through a co-solvent method, the crystal is easy to operate, low in cost, large in size, short in growth cycle, few in inclusion, large in mechanical hardness and easy to cut, polish and preserve, and the lead barium borate nonlinear optical crystal can be widely applied in nonlinear optical devices such as frequency-doubling conversion and optical parametric oscillators.

The invention discloses a transparent broadband electromagnetic wave absorber based on an ITO resistive film, which belongs to the technical field of electromagnetic materials and comprises an upper glass substrate, a lower glass substrate, ITO periodic units etched on the two glass substrates and having different sheet resistance values, and a middle transparent glass substrate, the periodic unit structure is a square ring patch, and the square ring patch is a layer of thin film formed by etching ITO with square resistance on a glass substrate. The middle layer selects glass for impedance matching to achieve the purpose of transparency, ITO with sheet resistance is completely etched on the bottom layer glass substrate, and the bottom layer ITO can be regarded as a metal reflecting plate due to the fact that the sheet resistance of the bottom layer ITO is very small, and the conductivity of the bottom layer ITO is close to that of a perfect metal conductor. The wave absorber realized by the resistive ITO and the glass breaks through the limitation that the traditional wave absorber is opaque and narrow in bandwidth, the application scene is widened, and the wave absorber has important application prospects in the aspects of electromagnetic shielding, cockpits with requirements on light transmittance and the like.

The present application relates to a barrier membrane for guiding bone regeneration technology. The barrier membrane comprises two layers of first absorbable films and a supporting layer clamped between the two layers of first absorbable films, the supporting layer comprises at least one supporting piece, and the supporting piece is made of magnesium alloy.

A sensor and method of manufacturing a variable resistance sensor with a protective sheath that is cost effective and highly reliable, with stable resistance with an operating range of up to 1700° C. in hostile environments. The sheath is formed of highly stable dispersion hardened materials capable of withstanding mechanical loads and chemical attacks at elevated temperatures while maintaining internal chemical integrity.

The invention discloses a water-based metal priming paint for vehicles, and belongs to the technical field of paint coatings. According to the water-based metal priming paint for the vehicle, a water-based acrylic dispersion, a water-based acrylic polyurethane dispersion and a water-based polyurethane dispersion are compounded in proportion, so that the obtained product is more environment-friendly than traditional oil-based vehicle paint, and meanwhile, the defects that the water-based vehicle paint is low in resistance and paint is easy to fall off are overcome; when the product is used forspraying paint on vehicles, a paint film connection port is smooth in transition, silver powder is arranged well, and the interlayer adhesive force is excellent; the paint has the advantages of favorable water resistance, favorable high-temperature resistance, favorable weather resistance, favorable acid resistance, favorable alkali resistance, favorable gasoline resistance, favorable engine oil resistance, high hardness, and high toughness and favorable MEK wiping resistance, and is suitable for large vehicles such as coaches, refitted vehicles, rail transit vehicle bodies and the like. The invention also discloses a preparation method of the water-based metal base color paint for vehicles, and the preparation method is environment-friendly and economic, has simple operation steps, and can be used for industrial large-scale production.

A method of making SiC nanowires comprising: (a) mixing silicon powder with a carbon-containing biopolymer and a catalyst at room temperature to form a mixture; and (b) heating said mixture to a pyrolyzing temperature sufficient to react said biopolymer and said silicon power to form SiC nanowires.

A disc device has a plurality of arms configured to support the outer rim of a disc carryable. Automatic loading is applied such that the disc inserted can be carried in the device, and the disc housed inside the device can be carried out of the device. A pair of shutter pieces are located on the central portion of a slot in a front bezel to be used to insert the disc therethrough and are spaced at a certain interval. The shutter piece rotates about one end thereof to raise / tumble the other end thereof. The tumbled shutter piece changes to the raised state after the disc is housed in the device while the shutter piece changes to the tumbled state before the disc housed inside the device is carried out of the device.

The invention provides an iron-based amorphous magnetically soft alloy magnetic powder core with an organic-inorganic mixed coating and a preparation method of the iron-based amorphous magnetically soft alloy magnetic powder core. The magnetic powder core is prepared from the following raw materials: FeSiCr amorphous magnetic powder, nano metal oxide, tetrabutyl titanate, polyvinylpyrrolidone, AlN, TiB2, WC, 3-glycyloxy propyl trimethoxy silane, xylene and polysiloxane resin. According to the preparation method, polysiloxane resin is used for forming an outermost organic coating, the nano metal oxide, AlN, TiB2 and WC are used for forming a middle wrapping layer to wrap the FeSiCr amorphous magnetic powder on the innermost layer, thus the polysiloxane resin wrapped AlN / TiB2 / WC / nano metal oxide-FeSiCr amorphous magnetic powder is obtained, and the final ring-shaped magnetic powder core prepared by using the magnetic powder core has the advantages of high mechanical property, high resistivity, high magnetic conductivity and low magnetic loss due to the organic and inorganic double-layer coating.

The invention discloses a solid electrolyte based on iron pillared clay and ionic liquid and a preparation method thereof. The solid electrolyte is composed of the iron pillared clay, the ionic liquidand lithium salt, and the preparation method comprises the following steps of 1) performing drying pretreatment on the lithium salt, the ionic liquid and the iron pillared clay; 2) mixing a lithium salt and an ionic liquid to obtain a lithium salt-ionic liquid mixture; 3) mixing the iron pillared clay and the lithium salt-ionic liquid mixture, and baking. According to the solid electrolyte, the iron pillared clay serves as a matrix, the ionic liquid and the lithium salt are immobilized in the iron pillared clay, and the solid electrolyte is higher in ionic conductivity and energy density, good in contact with a positive electrode and a negative electrode, higher in mechanical hardness, good in interface stability and low in raw material cost.