In the reinforced steel fiber concrete beam reinforced by carbon fiber cloth, the reinforcement effect is affected by the performance of the reinforced structure itself, the performance of the reinforcement material and the load situation, so the reinforcement effect has a very high nonlinearity. In order to solve this problem, on the basis of experimental research, a BP neural network model for predicting the bending bearing capacity of reinforced beams is established by using the neural network method, taking 10 variables such as steel fiber concrete strength, section size, longitudinal reinforcement ratio as input units, and the bending bearing capacity of reinforced beams as output units. Through the comparative analysis of the predicted value and the experimental value, the scientificity and rationality of the model are verified.

Considering the rigid body displacement and bending deformation of the single-fulcrum pile anchor support structure, the horizontal displacement calculation method of the anchor point and the top of the supporting pile is established. By analyzing the effect of various influencing factors of horizontal displacement on displacement, it is pointed out that the downward shift of the bolt position will increase the tensile force of the bolt and increase its reinforcement, but the horizontal displacement deformation of the pile top after the anchor tension and anchoring can be reduced.

In order to determine the viscoelastic parameters of asphalt mixture, stress relaxation test was carried out at 10,5,0,-5,-15,-20,-25,-30 °C. The analysis points out that the fatigue failure of asphalt mixture can be analyzed with the cumulative dissipative energy, and there is a unique relationship between the cumulative dissipative energy and the fatigue life, and other factors such as test method, loading frequency, loading mode, temperature, etc. have little effect on it. Finally, the solution method of cumulative dissipated energy is briefly described.

The shear strength of concrete specimens under freeze-thaw cycle was studied by Z-shaped specimen shear test method, and the mechanism of freeze-thaw damage of concrete was preliminarily analyzed. The results show that the relative shear strength of concrete decreases with the increase of the number of freeze-thaw cycles under the action of freeze-thaw cycle, because the freeze-thaw cycle causes damage between the cement stone itself and the cement stone and the aggregate, which reduces the strength of the concrete.

Fly ash bleaching, G alkali-metakaolin-based cementitious material Geopolymer (ordinary cement as the contrast sample) and water were mixed in proportion to form 3 cm×3 cm×3 cm test blocks and cured for 28 days. The test block is calcined at a specified temperature and time, and its thermal stability is judged by its remaining compressive strength. The test results show that the residual compressive strength of Geopolymer increases with the increase of calcination temperature, and shows a significant increase trend from 800 °C to 1 000 °C, while the residual compressive strength of ordinary cement decreases with the increase of calcination temperature. Differential thermal analysis and thermogravimetric analysis of the hydration products of Geopolymer and cement were carried out, and it was found that Geopolymer had excellent thermal stability properties, which may be caused by the special hydration products of Geopolymer.

The basic principle and implementation steps of static elastoplastic analysis in SAP2000n program are analyzed, and some of these parameters are adjusted in combination with Chinese standards. Finally, the static elastoplastic analysis and seismic performance evaluation of a four-layer frame were carried out by program. The results show that this method can comprehensively and quantitatively evaluate the structure from the aspects of interlayer displacement angle, plastic hinge distribution and deformation, and can reveal the weak links of the structure under the action of rare earthquakes, which is an effective method to realize performance-based design.

In order to study the influence of carbon fiber reinforcement on beam performance, by comparing the unreinforced concrete beams, the bending test of reinforced concrete beams in two different states of cracked and uncracked reinforced concrete beams reinforced with carbon fiber cloth was designed. In the case of the initial state of the steel bar is not yielded, regardless of whether the reinforced front beam is open or not, the main failure feature of the beam is that the carbon fiber cloth is broken in the span; Under the condition of ensuring good adhesion, the yield load and ultimate load of the two reinforcement beams are increased to the same extent. Pasting carbon fiber cloth on the bottom of the beam can effectively limit the development and extension of cracks, so the ductility and stiffness of the reinforced beam are improved. After the steel bar yields, the load is mainly borne by carbon fiber cloth, but its strength can only exert about 60%.

In the early stage of concrete hardening, non-load cracks are easy to occur because the shrinkage strain and shrinkage stress of concrete are large at this time, but the tensile strength is relatively low. In order to obtain a more accurate early tensile strength of concrete, the self-designed concrete axial tensile test device was used to successfully solve the problem of difficult alignment of specimens, and the axial tensile strength tests of 20 d, 40 d, 60 d and 3 d of C3, C7 and C14 three strength grades of commercial concrete were carried out, and the test results were not discrete, and then the law of the early axial tensile strength of commercial concrete with time and its relationship with the compressive strength of the cube were obtained. The relationship between axial tensile strength and splitting strength of commercial concrete is discussed, and it is found that the conversion coefficient between the two in the specification is biased and safe.

Urban disaster prevention research should not only re-examine and formulate a new version of building disaster prevention standards, but also conduct in-depth discussions on the shortcomings of long-term urban spatial planning, the spatial distribution of various functional systems of cities and their relationship with the disaster environment. Using the perspective of the system, the concept of urban disaster prevention space is proposed from the three levels of macro, meso and micro, and the basic principles that should be followed in the planning of urban disaster prevention space system are pointed out: combined with human behavior patterns; Combined with urban construction and economic benefits; Combined with environmental protection. Only in this way can sustainable urban spaces be created.

Y2O8/ZrO2 ultrafine powder was prepared by co-precipitation process using ZrOCl3·3H6O, Y(NO2)2·3H2O, concentrated ammonia, etc. as starting materials. The effects of ZrO2 seed dosage, precursor reaction temperature, reactant concentration, reaction system pH, dispersant dosage, aging temperature and heat treatment temperature on the synthesis of Y2O3/ZrO2 ultrafine powder were studied. The results show that the grain size of the powder prepared under experimental conditions is about 15 nm, and the secondary particle size is about 100 nm. The initial formation temperature of Y2O3/ZrO2 ultrafine powder was about 400 °C.

SiC/Cu coated composite powder was selected and SiC/Cu cermet composites were prepared by the latest discharge plasma sintering method. XRD, SEM and other methods were used to characterize the fired samples. The results show that during the sintering process of discharge plasma, the substances in the firing sample and the corresponding content change due to the action of plasma. The density of the sample increases with the increase of temperature, and the hardness peaks at about 730°C, which is the optimal firing temperature for the preparation of SiC/Cu cermet composites by discharge plasma sintering. Due to the reinforcement of SiC, the hardness of SiC/Cu cermet composites is much higher than that of Cu.

Differential transformer sensor is a kind of sensor widely used in industrial production site, because of the structural parameters that determine the output characteristics of such sensors, such as the number of coil turns, core diameter, skeleton material and geometry, etc., so it is more difficult to optimize the configuration of system parameters, in fact, high-quality materials and high-precision processing technology are selected to ensure excellent output characteristics. The sensing characteristics of (Fe50Co50)72B20Si4Nb4 Bulk Metallic Glass (BMG) as the core material of differential transformer displacement sensor were studied. The experimental results show that under the same conditions, the sensor using metal glass as the core has higher sensitivity, better stability, greater signal-to-noise ratio, and smaller iron loss at higher excitation power frequency ω. Moreover, the core made of metal glass has a small size, high resistivity and small eddy current loss, so the repetition rate of the current can be relatively high, which effectively expands the frequency response range of the sensor.

Ni20Zr 10 Al70 amorphous alloy strip was successfully prepared by adjusting various process parameters by using rapid solidification single-roll planar flow casting technology. The amorphous structure of the alloy was verified by XRD, TEM and SAED, and the phase composition of the alloy at different solidification rates was analyzed. The results show that with the increase of solidification rate, the solidification of Ni20Zr 10Al70 alloy is first inhibited by the crystallization of NiAl3 phase and α-Al phase. With the further increase of solidification rate, the crystallization of Ni0.3 Al1.7Zr phase was also inhibited. The solidification rate is further increased, and the crystallization of Ni2Al3 phase is also inhibited, and finally a complete amorphous structure is obtained.

The triangle packing problem is NP difficult, and the time complexity of the complete algorithm is exponential. A mathematical model for solving the triangle packing problem was established. Along the anthropomorphic path, by comparing the problem to be solved with human social experience, several anthropomorphic strategies for solving the triangle packing problem are obtained, and an efficient approximation solving algorithm is developed based on this strategy. Experimental results show that the algorithm for solving the triangle packing problem along this path has better completeness and lower time complexity for the case of a large number of triangles.

A new aircraft identification system is proposed, which adopts the method of moment invariant to describe the characteristics of aircraft. The Levenberg-Marquardt algorithm and elastic algorithm are used to improve the standard BP network algorithm, so that the system has the characteristics of rapid and stable recognition process. The ×results show that the recognition accuracy of the system is above 360% and the recognition speed is relatively fast.

The electrochemical behavior of copper anode in sulfuric acid medium was studied by potentiodynamic scanning technology, and the effects of different electrolyte concentrations, different holding times, different holding potentials, and the presence of molecular oxygen and Cu2+ in the electrolyte on the cyclic voltammetry curve of copper anode were investigated. The results show that the presence of molecular oxygen and Cu2+ in the electrolyte, a longer holding time and a more positive holding potential can increase the peak current, which is conducive to the passivation of the metal. The passivation film formed in different concentrations of H2SO4 media has two layers, but its composition is different, and the passivation mechanism of copper is further inferred.

Based on the shake flask test, the bio-hydrogen production of simulated organic wastewater was carried out by using pretreated cow manure compost as the source of natural anaerobic microbial strains. The results showed that under the experimental conditions, the reactor had a continuous hydrogen production capacity of 140 mL/(L·h), an average hydrogen content of about 50%, and an average removal rate of COD of about 30%. The hydrogen production capacity of sucrose was 17 4 mL/g, which provided a theoretical basis for the feasibility of biological hydrogen production research in industrial development.

Hydrological phenomena in nature often imply periodicity, and based on this property, a hydrological time series cycle superposition prediction model was developed. The hydrological time series period superposition prediction model (POL) is introduced, the shortcomings of the hydrological time series period superposition prediction model (POL) in the application under some specific conditions are analyzed, and three improved models are proposed: trend-period superposition combined forecasting model (TPOLC), periodic superposition prediction model with compressed amplitude (AC-POL), and periodic superposition prediction model (DPI-POL) with inverse dominant period. It can be widely used in corresponding types of hydrological time series modeling.

Using the basic principle of genetic algorithm and taking the amount of timeliness as the basic influencing factor, a genetic algorithm model of earth-rock dam settlement was established. In the modeling process, in order to improve the search efficiency and model accuracy, the basic genetic algorithm is improved. Decision variables are encoded with floating-point numbers; Adopt an optimal preservation strategy; Arithmetic cross operators are used; A uniform variation operator is used. At the same time, the definition domain of the decision variables is determined from the optimization model and the settlement law of earth-rock dams, and the search scope is reduced to improve the search efficiency. The application example data of Luhun Reservoir show that the model is reasonable and has good accuracy, which can provide a new way for the settlement analysis of earth-rock dams.

The overview of the Tarim River Basin, the current situation of water resources development and utilization, the composition of the main stream of the Tarim River, and the current situation of water conservancy projects were analyzed, and it was pointed out that there were many practical problems in the basin, such as insufficient water shortage, high water quota, large water consumption in plain reservoirs, and backward comprehensive treatment and management of the river basin. The analysis of these water resources problems points out that the water quota should be lowered, the mountain reservoir should be built, the supporting facilities of the irrigation area should be renovated and improved, and the comprehensive management and management capacity of the river basin should be improved through two different ways: engineering measures and non-engineering measures, so as to solve the problems in the development and utilization of water resources.

For the problem of orthogonal continuous transmission encountered in the mechanical system, the groove wheel mechanism is used to design, which overcomes the cargo interference and extrusion phenomenon that is easy to occur in the general design, so that the designed orthogonal transmission mechanism has better transmission accuracy and motion stability. The mechanism is mainly composed of two parts: hoist and cargo machine. By adjusting the moving-stop ratio of the grooved wheel mechanism, the lifting movement and horizontal movement of the cargo can be carried out continuously. Its design features are simple structure, high transmission accuracy and economic practicality.

In order to improve the shear accuracy of high-grade corrugated cardboard and reduce the scrap rate, the microcomputer-controlled LXDNHQ-1800 spiral knife cross-cutting machine was developed, which uses spiral knife instead of straight knife, and adopts hollow knife roller and gapless gear transmission structure. The structure, transmission system and control system of the cross cutting machine are introduced, and the main technical parameters of the equipment are given. The shear results show that the cross-cutting machine has small shear force, high shear accuracy, smooth edge of shearing cardboard, low scrap rate, good reliability and high degree of automation.

The simplification of hydraulic system model is one of the main reasons restricting the improvement of the simulation quality of transient process of power system. Different forms of mathematical models of complex hydraulic systems for transient stability analysis of power systems are established, including rigid hammer models and elastic hammer models of water diversion systems, and linearization models and nonlinear models of hydro turbines. By calculating the transition process of multi-machine system with complex hydraulic system under large disturbance, the influence of different models of water diversion system and turbine on the transient stability calculation results is analyzed. The results show that different models of hydraulic system have little influence on the initial stage of transient stability calculation of multi-machine system. The rigid hammer model is close to the change curve under the elastic hammer model. The change curves under the nonlinear turbine model and the linear turbine model are quite different in the later stage of the transient process. The simplified model is too simple, and the calculation result error is large.

Considering the recent demand of China’s electricity market, a short-term load forecasting software system for power system was developed. The system is divided into three independent modules: raw data maintenance, load forecasting and forecast result processing. In the database design, the method of regular dumping is adopted to control the amount of data. The system provides a rich model library, each model can be predicted individually, or several models can be selected for comprehensive prediction. The load prediction results of a county-level power system in Henan Province show that the system can achieve satisfactory prediction effect.

When the superposition principle is used to solve the electromagnetic field vector edge value problem where the excitation source is a time-harmonic electric dipole, the second-order vector bits can be introduced to convert the vector problem into a scalar problem, and the second-order vector bits of the time-harmonic electric dipoles in infinite space must be obtained first. Using the transformation relationship between special functions and the reciprocity theorem, the second-order vector bits of time-harmonic electric dipoles in infinite space in spherical coordinates are derived from the magnetic vector bits of time-harmonic electric dipoles in infinite space. The form of second-order vector bits is more complex than that of magnetic vector bits, but in order to easily use the boundary conditions after the introduction of second-order vector bits, this conversion from simple to complex is necessary.

According to the mathematical model of the rotor synchronous rotation dc-qc-0 coordinate system of asynchronous motor, the simulation model of asynchronous motor based on the S function in the MATLAB SIMU LINK toolbox is derived, and the starting process of asynchronous motor is simulated. For asynchronous motors, based on the dynamic model under dc-qc-0 coordinate system, the stator and rotor currents are used as state variables, and the S function in MATLAB is used to solve the differential equation. The simulation results of the asynchronous motor verify the correctness of the model. This method is convenient in construction, good in real-time, highly portable, and highly extensible.

In the process of generating horizontal nuclear line images, the nuclear lines on the horizontal images are not parallel to each other for general horizontal image pairs, that is, when the baseline is not parallel to the geodetic coordinate system. In order to obtain the correct and effective horizontal nuclear line image, the ground coordinate system is rotated to the horizontal direction of the baseline, and the nuclear line on the horizontal image is rearranged by a method similar to that of non-horizontal nuclear line rearrangement according to the coplanar conditions, so as to eliminate the problem that the nuclear line and the scan line are not parallel to the scanning line generated by the baseline non-level, reduce the calculation amount of subsequent work such as mapping and matching, and improve the operation speed. Finally, the relationship between the baseline inclination angle and the maximum angle between the nuclear lines on the horizontal image is given, and it is concluded that the non-horizontal nuclear line image should be used when the baseline inclination angle is large to ensure the quality of the nuclear line image.