82results about How to "Low decay rate" patented technology

The invention relates to an energy-saving temperature-control phase-change material. The energy-saving temperature-control phase-change material is characterized by comprising compositions in percentage by weight: 50-90% of phase-change host, 1-40% melting point control agent, 0.1-10% nucleating agent, 5-15% of crystal modifier and the balance of water. Crystallized hydrated salt phase-change material has the advantages that raw materials are easily available, the price is low, the energy density is large and the like, and the defects of being supercooling, carrying out phase separating, blocking and the like also seriously hinders the popularization and application. The phase-change host is of crystallized hydrated salt, has fixed melting point, the phase-change temperature is regulated through adding the melting point control agent so as to be capable of completing meeting the requirement of normal application. The phase-change crystal particles are fine through adding the crystal modifier, phase separation can also be prevented, attenuation is slowed down, the stability of the phase-change materials is improved, and the service life of the product is prolonged.

The invention discloses an array antenna for generating microwave orbital angular momentum based on a phase gradient super-surface. The array antenna is formed by the arrangement of phase shift units (1), each phase shift unit (1) comprises a dielectric plate (3), a metal patch (4) is arranged on the surface of the dielectric plate (3), an upper hole (5) is formed in the middle of the metal patch (4), a metal ground plate (6) is arranged at the bottom of the dielectric plate (3), a lower hole (7) is formed in the middle of the metal ground plate (6), and a metal pipe (8) is arranged at the middle of the dielectric plate (3) and communicates with the upper hole (5) and the lower hole (7). The array antenna has the characteristics of small size, light weight and low cost; meanwhile, the continuous control of the orbital angular momentum in phases of 0 to 2Pi is further achieved, and obvious vortex orbital angular momentum is generated; and moreover, the array antenna has an excellent reflection effect.

Disclosed is an array ultrasonic probe, including a plurality of channels arranged with spaces, each channel having a piezoelectric element and a laminated acoustic matching layer structure formed of at least three layers and arranged on the piezoelectric element, a backing on which the piezoelectric element of each channel is mounted and having trenches in which are formed at places corresponding to the spaces, and an acoustic lens formed to cover at least the surface of the uppermost acoustic matching layer of each channel, wherein the uppermost acoustic matching layer comprises a silicone resin-containing mixture having a Shore hardness D not lower than 40 at 25 DEG C., and exhibits an acoustic impedance of 1.8 to 2.5 MRayls at 25 DEG C.

The invention discloses a PID (Potential Induced Degradation)-resistant circuit and a monitoring device thereof. The PID-resistant circuit comprises a photovoltaic cell, an inverter and a ground circuit, wherein the anode of the photovoltaic cell is connected with the anode of the direct-current input of the inverter through an anode relay; the cathode of the photovoltaic cell is connected with the cathode of the direct-current input of the inverter through a cathode relay; the ground circuit comprises a fusing protection circuit and a current sensor; the fusing protection circuit consists of a fuse and a protective resistor which are connected in parallel; and one end of the ground circuit is connected with the cathode of the direct-current input of the inverter, and the other end of the ground circuit passing through the fusing protection circuit and the current sensor is grounded. Due to the adoption of the PID-resistant circuit, the phenomenon of PID existing in a photovoltaic cell panel can be eliminated effectively; and meanwhile, ground leakage protection and detection are performed on an entire photovoltaic cell panel array, so that electric shock accidents are avoided and rapid detection of ground short-circuit fault is realized.

The invention discloses a solid-phase preparation method of an NCM811-type high-nickel ternary positive electrode material. The preparation method comprises the process steps of raw material mixing, primary sintering performed in three segments, composite coating agent coating, secondary sintering and processing after sintering. According to relevant performance test, the composite coating methodof doping nanometer Al2O3 and AlF3 or Al2O3 and LiF into a lithium ion battery positive electrode is employed, primary sintering is performed in three segments, sintering and oxygen introduction are performed, the capacity attenuation of the material can be effectively reduced under the condition that favorable reversible capacity of the material is maintained, the cycle lifetime is prolonged, andthe comprehensive performance of the lithium ion battery positive electrode material is improved.

The invention discloses a metasurface reflective array plane used for focusing electromagnetic waves. The super-surface reflective array plane comprises an array phase plate (2) formed by more than two phase shifting units (1), wherein each phase shifting unit (1) comprises a dielectric plate (3); a metal patch (4) is arranged on the surface of each dielectric plate (3); an upper hole (5) is formed in the middle of each metal patch (4); a metal grounding plate (6) is arranged at the bottom of each dielectric plate (3); a lower hole (7) is formed in the middle of each metal grounding plate (6); a metal tube (8) is arranged in the middle of each dielectric plate (3); and the metal tube (8) is communicated with the corresponding upper hole (5) and the corresponding lower hole (7). The metasurface reflective array plane has a quite excellent incident wave reflection and focusing effect; in addition, the incident wave reflection attenuation rate is lowered, so that the reflective effect of the metasurface reflective array plane is improved consequentluy; the reflection efficiency of the existing array antenna is normally 30-40%, while the reflection efficiency of the metasurface reflective array plane can reach 65%; and in addition, the metasurface reflective array plane also has the characteristics of small volume, light weight and low cost.

The invention discloses a non-contact temperature measurement device which comprises a controller, a driving circuit, a switching circuit, a resonance circuit, a temperature sensor and a signal detection circuit. Inductance and circuit internal resistance serve as resonant resistance of the temperature sensor, the resistance is small, and therefore the attenuation rate of temperature voltage signals is small during resonance, a plurality of periodic attenuation sinusoidal temperature voltage signals can be generated, and simultaneously device volume is correspondingly reduced. The invention further discloses a temperature measurement method of the non-contact temperature measurement device. The temperature measurement method is characterized in that a sampling signal differential equation is not needed to be solved due to the fact that discrete Fourier transformation is adopted as the basis, and computer analytical calculation is facilitated; and in frequency-domain analysis, the effective signal frequency and the useless interference signal frequency can be separated, frequency-domain analysis is visual in aspect of the physical meaning, signal interference can be reduced as far as possible, and further analysis and process are facilitated.

An elastic acting force structure of a furniture upturning device comprises a fixing support, a swing rod and a spring assembly, wherein the swing rod is arranged on the fixing support in a swinging mode and interact with the spring assembly during swinging, so that the spring assembly generates elastic acting force; the spring assembly comprises a front connection part, a rear connection part, a guide shaft and a spring; the guide shaft is sleeved with the spring; the two ends of the spring elastically act on the front connection part and the rear connection part; the two ends of the guide shaft are connected with one end of the front connection part and one end of the rear connection part in a matched mode; the other end of the front connection part is connected with the swing rod in a matched mode; and the other end of the rear connection part is connected with the fixing support in a matched mode. By improvement of the structure, the elastic acting force structure of the furniture upturning device has the characteristics of being simple and reasonable in structure, safe, reliable, easy to produce and achieve, rapid to adjust, convenient to operate, long in service life, smooth in opening and closing process, capable of saving labor, low in collision, low in noise, wide in use range and the like, and practicability is high.

The invention discloses a production technology of activated carbon for a high-capacity long-service-life supercapacitor, belonging to the technical field of activated carbon preparation technology. The production technology comprises the following technology flow: pretreatment, activation, washing, acid soaking, drying, grinding and mixing. Aiming at solving the defects that the capacitor of the prior art is low in capacity, large in leaked current and short in service life, the production technology comprises the following steps: firstly, pretreating to obtain carbonized materials, activating by adopting a microwave activation manner to obtain activated carbon with high specific surface area, washing metal impurities by adopting a super-washing manner, and performing microwave thermal treatment to remove surface functional groups to obtain high-quality activated carbon. The electric capacity of the activated carbon obtained by adopting the technology is larger than that of the carbon adopting abroad imported alkaline, the service life is longer than that of the carbon adopting abroad imported alkaline, and the attenuation rate is lower.

The invention discloses a high-strength absorbable bone screw for internal fracture fixation. The bone screw is prepared from a degradable oriented polylactic acid sectional material, wherein the raw material of the oriented polylactic acid sectional material is L-polylactide having a specific rotation of negative155-negative 160 degrees; the sectional material is prepared from L-polylactide sequentially through blank preparing, oriented reinforcing and quenching, the blank preparing method is injection molding, the oriented reinforcing method is forging and pressing or extruding; and the sectional material is manufactured into the bone screw through a turning method, a carving method or a direct molding method. The bone screw has high strength, small attenuation rate of mechanical strength, ensures mechanical support in a bone healing stage and sufficient heating time for injured bones, has good biocompatibility, can be degraded and absorbed, can be used for reducing osteoporosis, and has a remarkable effect on fixing cancellous bone fracture. Under a special condition, the size of the bone screw can be adjusted according to the ankle osteotomy, ankle fracture degree and the growth plate characteristics of ulna.

The invention provides an optical fiber type leakage detector used for a direct-current converter valve. The optical fiber type leakage detector comprises a liquid receiver provided with a valve base shielding mental plate, a platform, a volume collecting component and a leakage detecting component. The volume collecting component which is installed on the platform through a rack is connected with the leakage detecting component through the optical fiber. The volume collecting component comprises a tipping bucket, a balancing pouring weight, a rotating shaft and collimating lens. The leakage detecting component comprises an optical emitter, an optical receiver and valve base electrons. Compared with the prior art, the optical fiber type leakage detector used for the direct-current converter valve is simple in structure, high in measuring accuracy, low in optical attenuation rate and good in sealing performance.

The present invention provides a suspended graphene propagation plasmon waveguide device. The suspended graphene propagation plasmon waveguide device comprises a substrate, a graphene layer and an electrode which are disposed sequentially from bottom to top; the substrate comprises at least one hole structure and is used for supporting a graphene layer and an electrode; the graphene layer covers the hole structure of the substrate, so that a suspended graphene structure can be formed; and the electrode is used for electrical measurement and electrostatic regulation of graphene carrier concentration and is arranged on the graphene layer. According to the structure of the suspended graphene propagation plasmon waveguide device of the invention, propagation plasmons are supported on the suspended graphene structure; with such kind of structure adopted, the dielectric loss of the graphene plasmons can be effectively eliminated, and the decay rate of the plasmons can be reduced; and since the dielectric constant of the air is small, the wavelength of the plasmons on the suspended graphene is very long, and a long-wavelength propagation distance can be achieved with the low attenuation characteristic of the plasmons utilized.

The present invention provides an air ion conveyance device as well as an air ion conveyance system, for example, for an air conditioning facility and conveys air ions to rooms of a house etc. The air ion conveyance device has an air ion production device unit, air ducts, and a control device. The air ion production device unit is provided in a housing of a centralized ventilation device and has positive ion production devices and negative ion production devices that are alternately arranged with a spacing in between, the positive ion production devices generating positive ions in air fed from the outside, the negative ion production devices generating negative ions in the air. The air ducts are connected to joints provided at the housing and individually conveys air to rooms. The control device controls the air ion production device unit. The control device regulates, according to a request from each room, whether or not to produce air ions or the amount of production of ions.

The invention relates to a preparation method of a composite phase change energy storage material by using bentonite as a base body and using aliphatic dibasic acid as a phase change energy storage body, which belongs to the technical field of the preparing technology of energy storage materials and comprises the steps of: putting the bentonite, CTAB (cetyltriethylammnonium bromide) and deionized water into a reaction container to heat and stir; modifying the bentonite; preparing a eutectic system of aliphatic dibasic acid by using myristic acid (MA) and palmitic acid (PA), or lauric acid (LA) and myristic acid (MA); heating 20% to 37% of eutectic mixture of the aliphatic dibasic acid, 26% to 42% of modified bentonite and 36% to 44% of absolute ethyl alcohol in the reaction container to 75 DEG C; stirring for 2 hours; and drying a product in the reaction container to constant weight to obtain the aliphatic dibasic acid / bentonite composite phase change material. The material has good heat storage capability and the stability of storing heat circulation, and can be used for the fields of using waste heat, residual heat and solar energy and the like.

The invention relates to a negative-ion tile and a production process thereof. The negative-ion tile can increase concentration of negative ions in a room and avoid generation of ozone, positive ionsor static electricity and is safer and more environment friendly; negative air ions can be greatly and continuously generated for a long term, the negative ions are low in attenuation rate and can beeffectively combined with smoke, dust and impurities floating in the air, specific gravity of the negative ions is increased, the negative ions are settled, radiation generated from the static electricity, radio wave, computers, televisions and the like is neutralized, air is refreshed, and the radiation is reduced; meanwhile, with the specific production process, ceramics are better in resistanceto corrosion, oxidation and abrasion and have jewel luster on the surface, and a healthcare function is achieved.

The invention discloses a method for improving carrier attenuation of a PERC solar cell. The method comprises the steps of (1) reducing light-induced attenuation of the solar cell; (2) annealing the solar cell at a temperature of 300-600 DEG C; (3) preheating the annealed solar cell to a temperature of 250-450 DEG C; (4) carrying out first illumination treatment on the solar cell in a first temperature range for a first time; (5) carrying out second illumination treatment on the solar cell in a second temperature range for a second time; (6) introducing current into the solar cell subjected tothe second illumination treatment; and (7) cooling the solar cell to room temperature. Through the steps of annealing, preheating, high-temperature photo-thermal treatment, low-temperature photo-thermal treatment, electric injection and cooling, hydrogenation attenuation and attenuation caused by impurities are effectively reduced, and regeneration and recovery of the H and B-O complex from an unstable state to a passivated stable state are promoted, so that the CID attenuation rate of the solar cell is effectively reduced, and the conversion efficiency and reliability of the solar cell are improved.

The invention discloses a pulse metallic polypropylene film capacitor. The pulse metallic polypropylene film capacitor comprises a metal cylinder, a capacitor core, gold spraying layers, an upper insulation cover and a lower insulation cover, wherein the upper insulation cover and the lower insulation cover are fixedly connected by an explosion-prevention plate, a protection lead is arranged between the upper insulation cover and the explosion-prevention plate, an annular explosion-prevention gasket is arranged at each of the upper part and the lower part of the lower insulation cover, an impregnant is arranged in a gap between the metal cylinder and the lower insulation cover, the capacitor core is arranged in the metal cylinder, the gold spraying layers are arranged at the top end and the bottom end of the capacitor core, the capacitor core comprises a polypropylene film, the polypropylene film is evaporated with a metal layer in a high vacuum environment, and the metal layer comprises a wave-shaped double-sided metallic ZnAl layer, a first thickening layer and a second thickening layer. The pulse metallic polypropylene film capacitor has the advantages of excellent performance and high safety coefficient, and the capability of standing ripple current is high.

The invention relates to a magnetic resonance wireless power transmission device, in particular to a magnetic resonance wireless power transmission device based on a PCB resonant coupling coil structure. The magnetic resonance wireless power transmission device comprises an input power supply provided with the output end, a high frequency emitting power supply provided with the input end and the output end, an electromagnetic resonance coil provided with the input end and the output end and a rectifying and load circuit. Compared with the prior art, an electromagnetic resonance emitting coil is identical with an electromagnetic resonance receiving coil, both the attenuation rate of the electromagnetic resonance emitting coil in a resonance bandwidth frequency and the attenuation rate of the electromagnetic resonance receiving coil in the resonance bandwidth frequency are reduced, and energy transmission efficiency is improved.

The invention discloses a nitrogen-doped porous carbon loaded metal cobalt material as well as a preparation method and application thereof, which belong to the field of lithium-sulfur batteries. Thepreparation method specifically comprises the following steps of putting porous carbon into a water vapor environment of flowing ammonia gas, pouring the porous carbon adsorbing ammonia water into anethyl acetate solution dissolved with cobalt acetylacetonate, standing, carrying out suction filtration, and drying, and finally, calcining the dried product to obtain the nitrogen-doped porous carbonloaded metal cobalt material. The nitrogen-doped porous carbon loaded metal cobalt can be used for doubly adsorbing polysulfide through chemical adsorption and physical adsorption, so that the dissolution of polysulfide in an electrolyte is reduced, shuttling of polysulfide is effectively inhibited, and the conductivity of an electrode material is enhanced through porous carbon. The doping of nitrogen can accelerate the reaction kinetics process, and the porous carbon has a large internal space, so that the volume expansion of the positive electrode can be effectively relieved, and the stability of the battery is improved. And meanwhile, the diaphragm coated with the material is not easily punctured by dendrites to cause short circuit of the battery, and the safety of the lithium-sulfur battery is also guaranteed.

A multiple-piece golf ball includes a core positioned at the center of the golf ball; an intermediate layer surrounding the core; a cover further surrounding the intermediate layer; at least one high specific gravity member having a higher specific gravity than the core, the intermediate layer and the cover. The at least one high specific gravity member is arranged such that a moment of inertia of the golf ball with respect to an x-axis Ix and a moment of inertia of the golf ball with respect to a y-axis Iy are substantially the same, a moment of inertia of the golf ball with respect to a z-axis Iz is greater than Ix and Iy, and the difference between Iz and Ix or Iy is at least approximately 3. The x-axis, y-axis, and z-axis intersect orthogonally at the center of the golf ball.

The invention discloses an anti-fouling hollow fiber membrane and a preparation method of the anti-pollution hollow fiber membrane, and provides a hollow fiber membrane capable of resisting fouling of colloidal substances and protein, and the preparation method of the hollow fiber membrane. The preparation method comprises the steps of fully mixing 1-3% of sodium polyacrylate and 3-5% of water, then fully mixing 15-20% of a polymer, 63-65% of a film formation solvent and 10-15% of a film formation additive with the above mixture, removing air bubbles to obtain casting film liquid, extruding the casting film liquid by a spinning nozzle, then enabling the casting film liquid to enter a coagulating bath at 60-80 DEG C, drying at 80-100 DEG C after coagulating for certain time, so as to obtain the anti-fouling hollow fiber membrane, wherein the coagulating bath is aqueous solution containing sodium polyacrylate cross-linking agents. The hollow fiber membrane can effectively reduce nonspecific binding of membrane surface and pollutants such as protein and colloid through a hydrophobic bond, and reduces the membrane surface adsorption, so that the membrane flux is relatively stable and the attenuation rate is reduced.

The invention discloses an intelligent dual-glass solar module. The intelligent dual-glass solar module comprises a first glass layer, a first EVA layer, a solar battery layer, a second EVA layer, a second glass layer, a cable and a connector, wherein a groove is formed in the surface of the second glass layer; a circuit board is placed in the groove; a plurality of bypass diodes and a plurality of power optimizing modules are integrated on the circuit board; the solar battery layer comprises a plurality of solar battery strings; one end of each solar battery string is connected with a bus bar while the other end is connected with the circuit board; the bypass diodes and the corresponding solar battery strings are in anti-parallel connection; and the power optimizing modules are connected with the corresponding solar battery strings for tracking the maximum power point of each solar battery string. By embedding the circuit board, which is integrated with the bypass diodes and the power optimizing modules, in the model, and by tracking the maximum power point of each solar battery string, the power output maximum of the module is realized, and the module has higher reliability.

The invention relates to a medium-temperature SOFC (solid oxide fuel cell) flat-plate anode-supported monocell anode structure which comprises an anode functional layer and an anode support layer in tight connection with the anode functional layer, wherein the anode functional layer is obtained through sintering of NiO powder and YSZ (Yttria Stabilized Zirconia) powder of which the mass rate is (45-55) :(55-45) and which are doped with a pore-forming agent accounting for 3-6 wt% of the NiO powder and the YSZ powder based on total weight, the anode support layer is obtained through sintering of the NiO powder and the YSZ powder of which the quality mass rate is (50-60) :(50-40) and which are doped with the pore-forming agent accounting for 5-9 wt% of the NiO powder and the YSZ powder based on total weight, an anode structure blank is produced through double-layer curtain coating, and the anode structure is obtained through hot pressing, leveling and high-temperature co-firing of the anode structure blank. The monocell anode structure is simple and effective, and is easy to implement at industrial scale, the preparation method can be also applicable for industrial-scale production, and stability and high consistence through mass production are guaranteed.

The invention discloses an ultrasonic bathtub, comprising a bathtub and a plurality of ultrasonic oscillators arranged on the bathtub, wherein the ultrasonic oscillators are adhered tightly to the outer wall of the bathtub by fixing glue; the ultrasonic oscillators are connected with a drive circuit module by connection lines; the position of the outer wall of the bathtub corresponding to the ultrasonic oscillators is embedded with connection sheets; the emitting sides of the ultrasonic oscillators are adhered tightly to the connection sheets by the fixing glue; the connection sheets are made of toughened glass sheets or metal sheets; the drive circuit module is connected with a control panel capable of adjusting the transmission power of the ultrasonic oscillators by a signal line; and a live line terminal and a zero line terminal of each ultrasonic oscillator are wrapped with waterproof plastic covers. With the adoption of the ultrasonic bathtub provided by the invention, the defects of the existing ultrasonic bathtubs are overcome, and the attenuation rate of the ultraviolet in transmission can be effectively reduced, so that energy loss is reduced, and the functions of cleaning human skins, massaging and cleaning the surface of the bathtub can be better realized.

The invention discloses a preparation method of a high-stability dual emulsion and application of the high-stability dual emulsion to astaxanthin carrying. A solution containing gel substances is used as an internal water phase W1, glyceride containing polyglycerol ricinoleate (PGPR) is used as an oil phase O, and a W1 / O emulsion is obtained under the condition of shear emulsification. A water phase W2 dissolved with sodium caseinate is added into the preliminarily obtained W1 / O emulsion, high shear treatment is performed to obtain a W1 / O / W2 dual emulsion, a gel solution is added to the outermost layer of the formed dual emulsion, and shear treatment is performed again to obtain the final high-stability dual emulsion. According to the invention, the dual emulsion has better stability, so that the dual emulsion can be more widely applied to the fields of food, medicines, cosmetics and the like.

The invention discloses an electromagnetic valve. The electromagnetic valve comprises a valve body, valve seats and coil assemblies, wherein valve cavities are arranged in the valve body; air inlets and control ports are formed in the valve seats; first through holes for communicating the air inlets with the valve cavities and second through holes for communicating the valve cavities with outside are formed in the valve body; each coil assembly comprises a movable iron core, a sealing plug is inlaid to the movable iron core, the upper end surface of the sealing plug is in tight fit with the corresponding first through hole under the driving of the movable iron core, the lower end surface of the sealing plug is in tight fit with the corresponding second through hole under the driving of the movable iron core, non-return diaphragms matched with the corresponding first through holes are arranged in the corresponding valve cavities, and when sudden dropping disturbance of air pressure in the air inlets occurs relative to air pressure in the valve cavities, the non-return diaphragms are tightly attached to the corresponding first through holes under the action of pressure difference, so that air pressure stability of the control ports is guaranteed. The electromagnetic valve has the characteristics as follows: pressure of output work gas is stable, gas pressure attenuation is lower, intake and exhaust speeds are high, a terminal is simple to process and manufacture, and the protective performance is good.

The invention discloses a method for manufacturing high-brightness low-attenuation LEDs. The method comprises the following steps: (1) taking a silicon carbide substrate and manufacturing a gallium nitride LED crystal epitaxial wafer on the silicon carbide substrate; (2) detecting the surface and the thickness of the gallium nitride LED crystal epitaxial wafer; (3) dividing the gallium nitride LED crystal epitaxial wafer into a plurality of repeated units through a wafer expansion machine; (4) dispensing low-attenuation insulating gel and welding wires; (5) dispensing light decay resistant original gum on the gallium nitride LED crystal epitaxial wafer; (6) pouring a packaging adhesive; (7) detecting light splitting after demoulding; and (8) packaging and warehousing. The manufacturing method provided by the invention is convenient to operate, and is practical; and LEDs manufactured by adopting the method are high in light efficiency, light output brightness and reliability, long in service life and low in attenuation.

Being positioned between inner conductor and outer conductor, the insulator is in shape of corrugated pipe. Being composed of thermoplastic fluoride bearing resin, the insulator includes an insulated layer and insulated ribs. The insulated layer includes a circumference face cladding the inner conductor. Insulated ribs are extruded from the insulated layer along radial direction, and are contacted to outer conductor. The insulated ribs possess continuous shape in axial direction. Three more insulated ribs are distributed along circumferencial direction discretely in each other.

The invention belongs to the technical field of nondestructive testing of civil engineering structures, and provides a reinforced concrete structure crack depth detection method and device based on horizontal shear waves. The method comprises the steps: firstly, detecting and obtaining the propagation speed of the horizontal shear waves in concrete in an intact area; secondly, carrying out detecting at the crack to obtain first arrival wave travel time after diffraction at the crack end; and calculating the crack depth by combining the measured wave velocity, the horizontal distance between the sensor and the transmitting end and the first arrival wave travel time after crack diffraction. A receiving end of developed equipment is provided with a plurality of sensors capable of simultaneously receiving a plurality of signals which are transmitted by the same wave source end but pass through different propagation paths, and an average value of crack depth is calculated by utilizing the plurality of signals detected once and is used as an optimal estimation value of once detection; and the accurate nondestructive testing method for the concrete crack depth is developed, and the methodhas important engineering significance for quantitatively evaluating concrete diseases and ensuring the use safety of the structure.

The invention discloses a silicon-carbon composite anode material and a preparation method thereof, and relates to the field of battery materials, in particular to the field of anode materials of lithium ion batteries. The anode material is characterized by being a graphite / ferroferric oxide / lithium metaaluminate / titanium dioxide composite prepared from sodium dodecyl benzene sulfonate, ethylene glycol, ferric chloride, sodium acetate, lithium metaaluminate, glucose, titanium flakes, a sodium hydroxide solution and graphite by multiple physical mixing and chemical reactions. The problems of low gram capacity and poor rate performance of current graphite anode materials are solved, the prepared material has the advantages of high gram capacity, excellent rate performance and good processingperformance, and the comprehensive performance of the anode material is improved.