366 results about "Propagation rate" patented technology

The present invention provides a multiaxial short crack propagation life prediction method based on a critical surface method, and relates to the field of multiaxial fatigue strength theory. The algorithm comprises the steps of: (1) selecting a plane, which contains the maximum shearing strain range, as a critical surface, and using the damage parameters on the critical surface to characterize a short crack propagation driving force; (2) based on the shear-type multiaxial fatigue damage parameters, establishing an equivalent crack stress intensity factor applicable to the multiaxial stress state; (3) fitting the short crack propagation rate data under uniaxial loading to obtain an uniaxial short crack propagation curve; and (4) carrying out plastic zone size correction on the crack tip, and calculating the short crack propagation life by a fracture mechanics method. The method can well descript the influence of non-proportional loading on crack propagation. The results show that the method can well predict the short crack propagation life under multiaxial proportional and non-proportional loading.

The present invention discloses a guava quick propagation method which comprise the following steps: selecting daylight booth or green house of 70% transmittance, dipping cutting in rootage agent and inserting it to medium, keeping indoor relative humidity at 85%-100%, temperature at 25-40 degree, keeping indoor temperature at 25-35 degree after rooting, relative humidity at 75-85%, transplanting the cutting outside of green house for cultivation after the lateral root occur. The propagation rate is quick, rootage rate and transplanting survival rate is high in the present inventive method.

The invention discloses a method and a system for underwater short-distance data communication through a light-emitting diode (LED) light source. The method comprises the following steps that: a transmitting terminal codes a data signal to be transmitted, and the coded signal modulates the LED light source to transmit an LED light signal, wherein the LED light signal comprises data information to be transmitted; and a receiving terminal performs photoelectric conversion and demodulation on the received LED light signal, and then restores the data signal to be transmitted. In the method, the LED light signal serves as a carrier for data communication underwater. Compared with the underwater data communication technology adopting the acoustic technology in the prior art, the underwater short-distance data communication manner adopting the acoustic technology has the advantages of high bandwidth, small propagation delay, high propagation rate and the like.

The invention discloses a crack propagation rate measurement method. The method comprises the steps of applying alternating load to a test piece with a single-side penetrated crack by a testing machine; measuring load-displacement curves at an interval of certain loading cycles and fitting a linear segment to obtain the non-dimensional flexibility value of the test piece; acquiring the length of the crack according to the relation of the non-dimensional flexibility value of the single-side penetrated crack and the length of the crack under a clamped boundary condition; recording the number of the current loading cycles to obtain a crack length-load cycle number curve, and determining the crack propagation rate; and calculating the corresponding stress intensity factor, acquiring discrete data and fitting to obtain the parameters of the crack propagation rate. The method has the advantages that the method is suitable for measuring the crack propagation rate under positive and negative stress ratios and can be used for measuring the crack length automatically; and the measurement system has wide application range and is particularly suitable for measuring the crack propagation rate of novel materials such as a metal laminated board, a metal/composite material laminated board, a ceramic matrix composite material, a welding material.

The invention discloses a method capable of carrying out fatigue crack propagation rate estimation and life prediction. The method comprises the following steps: (1) carrying out a fatigue crack test, and recoding data including crack length, time and the like; (2) processing the data to estimate a propagation rate corresponding to the crack length; (3) taking a Paris formula as a least-squares fit line to determine metal material parameters; (4) establishing a crack propagation perturbation series model to obtain a control equation and a boundary condition; (5) selecting a perturbation parameter asymptotic expansion control equation to form a perturbation parameter asymptotic sequence; (6) combining like terms to obtain differential equations under different powers to determine a coefficient to be determined, and carrying out iterative solving on the differential equations to obtain boundary conditions during next calculation; and (7) utilizing a calculation result to finish crack propagation rate estimation, judging whether the crack length exceeds a critical crack or not, jumping to (5) if the crack length exceeds the critical crack, and finishing fatigue life prediction if the crack length exceeds the critical crack. The method can effectively estimate the crack propagation rate and predict the fatigue life, and improves calculation precision.

The invention discloses a prediction method of a crack propagation life of an aircraft body. The prediction method comprises the following steps: obtaining a random loading spectrum of an aircraft in flight according to the practical flight situation of the aircraft; dividing the obtained random loading spectrum into a plurality of sections, and respectively performing rain-flow counting and constant amplitude on each section, so that each section is approximated as a block loading spectrum; according to an Miners progressive damage theory, calculating a cycle life lambda effected on a crack of each block loading spectrum under the state of a corresponding stress ratio R, performing a fatigue test under the suitable stress ratio, and obtaining a corresponding stress-life curve; according to an equal defect theory, selecting the correspondence life curve under the suitable stress ratio R in the stress-life curve, and obtaining the equivalent stress Seq corresponding to the same life by a point tracing method; then, according to the R and the Seq, obtaining a maximum stress value sigma max and a minimum stress value sigma min of the equivalent cyclic stress; according to parameters of the equivalent cyclic stress, calculating the propagation rate of the crack when the obtained block loading spectrum is acted on the aircraft body.

The invention relates to a method for improving the damage-tolerance property of a 2,000-type aluminium alloy plate material. In the method, preferable hot-rolling outlet temperature, high-temperature softening treatment and smaller cold-rolling deformation in softening treatment process can be controlled, so that intercrystalline energy storage of the material is reduced, recrystallization degree is controlled and a malleableized texture is formed. By the method, the service life of the 2,000-type material such as 2,024, 2E12 and the like is prolonged by 2 to 4 times; the crack propagation rate is reduced to 1/4 to 1/2 of the original crack propagation rate; the production efficiency is improved; and the energy is further saved.

The invention discloses a fatigue life prediction method for a friction stir welded component based on small crack propagation, and belongs to the technical field of fatigue diagnosis and analysis ofmechanical structures. The method comprises the steps that a bone-shaped flat plate sample is prepared, fatigue small crack propagation replica tests under different stress loads and different stressratios are conducted on different areas of a joint, and a secant method is adopted for calculating the propagation rate of small cracks; a New-Raju model is adopted for calculating the stress intensity factor range of the small cracks of the joint; c values in the depth direction and a/2 values in the vertical direction of semi-arc shapes of fatigue crack propagation zones in fracture shapes of different areas of the joint, and the depth-to-length ratio 2c/a of the cracks is calculated; a curve of the propagation rate of the cracks along with the change of the stress intensity factor range isdrawn; an effective stress intensity factor is calculated; a formula of the propagation rate of the small cracks is determined; an initial crack size a0 and a critical crack size ac are determined; the formula of the propagation rate of the small cracks is integrated to obtain the fatigue life of the welded component. By means of the scheme, the fatigue life of the friction stir welded component can be more easily and accurately predicted.

The invention discloses a coaxial medium phase shifter and related application thereof, and improves a phase shifter of a conventional mobile communication antenna. The phase shifter is used for adjusting the phase of signals flowing through the phase shifter and comprises an inner conductor and an outer conductor; the inner conductor defines at least two parallel conduction arms in an integrated-molding way; the outer conductor is provided with coaxial cavities for each of the conduction arms; the conduction arms are sleeved in the coaxial cavities; and medium elements which move along the axial direction of the coaxial cavities to change the phase of the signals are sleeved between the outer conductor and the conduction arms. The propagation rate of radio frequency signals passing through the phase shifter can be changed by the linear reciprocating movement of the medium elements along the axial direction, so that the phase of the signals is changed to fulfill the aim of phase shift. The coaxial medium phase shifter overcomes fixed thinking modes, changes the structure of a conventional coaxial phase shifter, realizes phase adjustment through the movement of the medium elements relative to the coaxial cavities, optimizes both the electrical and physical properties of the phase shifter, serves as a base element, and has an optimistic application prospect.

The invention discloses an interaction system and method, a client, and a background server and belongs to the technical field of computer Internet. The interaction system comprises a resource releaser client, the background server, and resource receiver clients. The resource releaser client is used for releasing a network resource to the background server. The background server is used for sharing the network resource with the plurality of resource receiver clients. Each resource receiver client is used for displaying the display interface of the network resource, providing a presented resource entry, and sending a presented resource instruction aiming at the network resource to the background server according to presented resource operation triggered on the basis of the presented resource entry. The background server is also used for executing the presented resource instruction and sending reward feedback information to the resource receiver clients according to the presented resource instruction. The interaction system and method solve low utilization rate and propagation rate of paid network resources in the prior art, and achieve a technical effect of both satisfying the income of the releaser and the propagation utilization of the network resources by means of a resource presenting function.

Belonging to the technical field of biomedical ceramic coatings and nano-materials, the invention relates to a zinc-doped porous nano-titanium oxide coating and its preparation method. The preparation method consists of the steps of: providing a zinc-containing electrolytic solution, and supplementing at least one electrolyte for assisting arc striking, and in the electrolytic solution, taking titanium or titanium alloy as the positive electrode and stainless steel as the negative electrode, conducting microarc oxidation treatment to the titanium or titanium alloy with a direct current pulse power supply, thus obtaining a coating with a porous nano-crystal structure, a pore size of less than 20micrometers and a surface crystal grain scale of less than 100nm. Specifically, the coating phase is anatase titanium oxide or a composite of anatase titanium oxide and rutile titanium oxide, and has zinc content of 0.01-50 wt%. The nano-titanium oxide coating of the invention has better biocompatibility than existing titanium oxide coatings. And osteoblasts on the surface of the coating have faster propagation rate and stronger vigor. Thus, the zinc-doped porous nano-titanium oxide coating in the invention can be used as a replacing material for positions such as thighbones, hip joints, dental implants and others that bear heavy loads.

A method (e.g., for monitoring a braking system of a vehicle system) includes monitoring fluid pressures of a braking system and modeled braking efforts of the braking system in a vehicle system traveling along a route, identifying one or more time periods at least one of before a brake event of the braking system or after the brake event, calculating residual forces exerted on the vehicle system during the one or more time periods, and determining at least one of an estimated braking effort of the braking system or an estimated propagation rate at which the estimated braking effort is applied by the braking system using the residual forces that are calculated.

According to the present invention, since the inside of a hole formed in a sidewall of a process vessel of a plasma processing unit is filled with a dielectric, a propagation rate of the electromagnetic wave to a pickup antenna is improved when an electromagnetic wave generated due to abnormality in plasma such as abnormal discharge is to be detected via the hole. Accordingly, it is possible to improve detection sensitivity without any change in size or length of the hole. Consequently, abnormal discharge in plasma processing can be detected with high accuracy.

The invention relates to a method for producing the lycoris by plant tissue culture, which comprises the steps of: (1) taking an MS (mass spectrometry) culture medium as a basic culture medium, and taking a 2, 4-D, IAA (indo acetic acid), NAA (naphthyl acetic acid), 6-BA (butyl acrylate) and IBA (iso butyl alcohol) as a regulated and controlled growth hormone preparation culture medium; (2) taking the bulb of the lycoris as an explant, and sterilizing; (3) vaccinating the explant of the bulb on a bulb inducing culture medium to culture in an inducing way so as to grow bulbils; (4) transferring the bulbils into a rooting culture medium to culture in a rooting way, so that the bulbils can independently absorb the nutrient elements from the soil and the matrix; (5) transferring the bulbils into the culture medium to culture; (6) opening an opening of a vaccination bottle to refine the seedling; withdrawing the bulbils, and transferring the bulbils into a nutrient cup which takes the vermiculite, the pearlite and the nutrient soil as the mixed matrix; and transferring the bulbils into a large tent, so that the survival rate reaches 94%-96%. The method is less in material taking, and economical in culturing; the culture condition can be manually controlled and is not influenced by the natural condition; the method is short in growing period, and high in propagation rate; and the quality of lycoris is guaranteed.

The invention relates to a tissue culture propagating method of Manihot esculenta Crantz. As one of the global three-top tuber crops and the number one alimentarn crop in Africa, the Manihot esculenta Crantz is currently ranked as a vital biological energy crop in our country. Stem section vegetative cottage is commonly adopted for propagation, and the low propagation rate thereof is a restrictive factor for popularizing the new variety and shortening the breeding period. The method of the invention comprises the following steps: the Manihot esculenta Crantz stem section with stem apexes or lateral buds is taken as an explant, and the Manihot esculenta Crantz tissue culture plantlets are quickly obtained in virtue of the micro-propagation method; young leaves, stem apexes and axillary buds of the sterile plantlets obtained from micro-propagation are taken as explants, somatic embryo generation and plant regeneration are induced, thus the Manihot esculenta Crantz somatic cell regeneration system is established. By adopting the method, the Manihot esculenta Crantz has the advantages of high propagation rate, no genotype dependence, and the like; the method has high value on the quick propagation and large-scale production of the Manihot esculenta Crantz improved variety in a short term, and establishes a technical basis for the Manihot esculenta Crantz transgene and other breeding.

The present invention discloses a multi-zone damage detection method based on Lamb wave signal correlation coefficients, by arranging of a sensor array in the structure, a monitoring area is divided into two basic monitoring units, and the basic monitoring units are identified by the method based on signal correlation coefficients for further monitoring area damage imaging. The damage signal arrival time can be extracted only by knowing of a rough Lamb wave propagation velocity in the structure without use of complex signal processing method and noise removal technique, the quality requirement of the signal is low, and environmental requirement of the structure is reduced.

The invention provides a radiation net fault location method by means of a zero mode and aerial mode time difference independent of double-end synchronization and with matching of the magnitude of voltages and the magnitude of currents, and belongs to the technical field of power system relay protection. The two sides of a feeder are respectively provided with a traveling wave fault location device, and fault location is carried out according to information on the two sides. After a ground fault of the feeder of a power distribution net occurs, due to sudden changes of the voltage at a fault point, an aerial mode traveling wave component spreading between wires and a zero mode traveling wave component spreading between the wires and the ground are generated. Due to the fact that the spreading speeds of an aerial mode and a zero mode are different, the arrival moment of an aerial mode traveling wave detected by the measurement end and the arrival moment of a zero mode traveling wave detected by the measurement end are different. According to original aerial mode voltage and current traveling wave data and original zero mode voltage and current traveling wave data detected by the measurement end, wave arrival moment calibration is carried out by means of a wavelet modulus maximum value under a fifth dimension, and then the fault position is calculated according to a calculation formula of a ground fault single-end traveling wave fault location method of modulus transmission time differences. Fault location is carried out according to measurement information of the single-end modulus transmission time differences at two sides.

The invention provides a device and a method for reckoning the fatigue crack propagation rate of a flat alloy by AC potentiometry, relating to the field of detecting material fatigue performance. The method comprises the following steps: in the process of a tension-tension fatigue test, two pairs of probes are arranged on the surface of a flat alloy sample, and the sample monitors electric potential change at the two sides of a crack in real time by an AC potentiometry sensor thereon when the fatigue crack propagates; the electric potential change is transmitted to a dual-trace oscilloscope by an amplifier; the dual-trace oscilloscope displays the electric potential oscillogram of the propagation of the two ends of the crack; and the electric potential oscillogram is input to a computer by an A/D converter, and is analyzed by a bundled software to obtain fatigue propagation rate such as the fatigue crack propagation rate and the like. The device of the invention mainly comprises a fatigue-testing machine, sample fixtures, the AC potentiometry sensor, potential measurement probes, lead wires, a signal amplifier, the dual-trace oscilloscope, the A/D converter, a CCD image acquisition system and the computer. The invention is applicable to research on the fatigue crack propagation behavior of the alloy.

The invention discloses a wood moisture content detection method based on radar waves. The wood moisture content detection method overcomes such shortcoming of the conventional weighing method as complicated detection process and is a real-time, continuous and lossless moisture content detection method. When the radar waves are transmitted in wood, the transmission speed, the amplitude intensity, the reflection time and the like of the radar waves are affected due to difference of dielectric constants in the wood, and the dielectric constants in the wood are closely relevant to the moisture content of the wood. The detection method comprises the steps of mounting a radar antenna (containing a radar wave emitting and receiving device, wherein the radar wave frequency is 900Mhz, and the wood which is 1m thick can be detected), a data manager (which can digitalize and store the radar waves emitted and reflected by the radar antenna for analysis and research), and a wood relative dielectric constant and moisture content relation model; emitting the radar waves to the wood with the known thickness through the radar antenna, collecting the reflected waves, calculating the double-journey traveling time of the radar waves in the wood through the data manager, calculating a relative dielectric constant of the wood, and obtaining the moisture content of the wood according to the wood relative dielectric constant and moisture content relation model.

The invention relates to the stress evaluation of a laser cladding layer and in particular relates to a nondestructive evaluation method of the stress of a cladding layer based on a critical refraction longitudinal wave. According to the invention, the nondestructive evaluation of the cladding layer stress is realized through selecting a double critical refraction longitudinal wave probe with a suitable central frequency; an optimum propagation distance is determined as the spacing distance between a propagation probe and a receiving probe to be fixed by combining the law that the energy of the critical refraction longitudinal wave in the cladding layer decays; the time difference between the critical refraction longitudinal signals is used for representing the change amount of the propagation speed of the cladding layer in the critical refraction longitudinal wave caused by the stress and taken as the characteristic parameter to evaluate the stress of the cladding layer to build a stress-time difference relation; a liner function is adopted to fit results to obtain an acoustoelastic equation used for representing the stress of the cladding layer, and therefore the nondestructive evaluation of the stress of the cladding layer based on the critical refraction longitudinal wave is realized.