In order to comprehensively and effectively consider the influence of various factors on the middle and long column members of the Yellow River silt porous brick masonry through limited tests, the design method of orthogonal test was used to carry out the compressive test of the middle and long column members of the Yellow River silt porous brick masonry, and the ultimate bearing capacity and strain data of each component were measured. Through the collation and analysis of experimental data, the compressive bearing capacity and deformation performance of the middle and long column members of the Yellow River silt perforated brick masonry under vertical load were studied, and the primary and secondary relationship of the influencing factors of each assessment index and the objective influencing trend were found, which provided some basis for the design and construction of the porous brick masonry structure of the Yellow River silt.

The thermal analysis (DSC and TG) of the geological polymer showed that 65% of the water was preserved after drying at 1°C for 14 h, of which 12% of the water was removed at 300°C, and the remaining chemically bound water was removed at 600°C. XRD analysis of geological polymers showed that between 20 °C~800 °C, the geological polymers were in an amorphous state, and KAlSiO1, SiO000 and Al4O2 began to form at 2 3 °C. The dehydration of geological polymers after high temperature or the disaggregation of three-dimensional network structure reduces the gelling strength of geological polymers.

Through the compressive test of 24 standard specimens built with recycled concrete perforated bricks, the crack development characteristics and failure characteristics of recycled concrete perforated brick masonry were discussed. According to the compressive test results of 24 specimens, the influence of crushed concrete content and the strength of masonry mortar on the compressive strength of masonry is discussed, and finally the recommended calculation formula for compressive strength is established.

There are 2 ways to apply prestress in the general finite element analysis software ANSYS: discrete and monolithic. In this paper, two methods for establishing finite element models are discussed in detail for the monolithic formula: the solid segmentation method and the independent modeling coupling method. Finally, for the unbonded concrete beams of the superstructure of Wangcun II Bridge of Line X2 in Pingdingshan City, a finite element model is established by applying the integral prestress and independent modeling coupling method to analyze the whole process of stress. Combined with the measured data, the calculated load-deflection curve, cross-sectional strain and concrete stress are compared, and the error can be seen to be within 017%, which verifies the feasibility and applicability of the proposed method.

Taking a single-layer elliptical parabolic grid shell with a span of 30 m× 30 m with practical engineering significance as the research object, the nonlinear overall stability performance of the grid shell was systematically analyzed by ABAQUS finite element program, and the influence of vector span ratio, initial geometric defects, constraints and other factors on the stability of the grid shell was considered. The buckling mode and buckling path of the grid shell were investigated, the whole process curve and ultimate stable bearing capacity were obtained, and the regularity of the overall nonlinear instability of the single-layer elliptical parabolic grid shell was comprehensively understood. The results show that the ultimate bearing capacity of the mesh shell gradually increases with the increase of the sagittal span ratio of the structure. It is sensitive to the asymmetric distribution and initial geometric defects of vertical loads, and the buckling load in the half-span vertical direction is only 70% of the full-span vertical load. The increase of the stiffness of the support can appropriately increase the ultimate bearing capacity of the grid shell.

Combined with sub-model technology, the solid element model and the plate and shell element model are established through a large-scale finite element program respectively for numerical simulation analysis. Three methods and implementation techniques of sub-model technology in the modeling and analysis of concrete box girder cantilever slabs were studied, and the influencing factors of the internal forces of the cantilever slab were investigated: thickness, length, box girder distortion and load action position. The results show that the width of the sub-model area is closer to the effective distribution width of the cantilever plate, the more accurate and efficient the calculation results of the substep method and the mixed mesh method are. For the effective beam segment method, the beam segment that is 3 times the effective distribution width is the best scale for calculating accuracy and calculating time. The solid element modeling comprehensively considers the influencing factors, and the analysis results are closer to the test results than the analysis results of plate and shell elements and other algorithms, and the sub-model technology is suitable for the local fine analysis of concrete box girder cantilever plates.

According to the characteristics of periodic variable load in highway bridges, the calculation method of fatigue stress amplitude of steel structure of highway bridge is given according to the current "General Code for Highway Bridge and Culvert Design" (JTG D62-2004). According to the difference in structural importance and replaceability, according to the whole life design idea, on the basis of long-term and extensive tests of the Research Institute of Science and Technology of the Ministry of Railways, a fatigue resistance equation with the guaranteed rate of allowable stress amplitude as a variable is proposed, so as to achieve the purpose of comprehensively considering the entire life of construction and bridge service during the design. Taking the fatigue calculation of a steel mixed stiffener beam of a highway suspension bridge as an example, the reliability of the proposed method is proved by comparison with other normative methods.

The effect of mixed cement and slaked lime on the properties of asphalt slurry was studied. By testing the high and low temperature properties and construction performance of asphalt slurry when cement and slaked lime were added under different replacement amounts, it was found that the softening point of the slurry increased, the viscosity decreased and the low temperature performance was improved after the addition of cement. However, when the replacement amount exceeds 60%, the improvement of the slurry ductility is reduced, so the cement replacement amount should not exceed 60%; When slaked lime was added, the softening point and viscosity of asphalt slurry increased significantly, and the BBR test showed that the low-temperature crack resistance deteriorated, but when the replacement amount did not exceed 20%, it had little effect on the low-temperature performance.

Based on the finite element theory, with the help of the general calculation program ANSYS, a finite element model was established for a solid bridge, and the changes of deflection, stress, self-resonance frequency and mode shape characteristics of the bridge under different load conditions were analyzed based on the detection results, and the static and dynamic characteristics of the bridge structure before and after reinforcement were studied. The results show that the anchor sprayed concrete reinforcement of the small hinged slab bridge effectively reduces the stress and strain of the section of the plate girder and improves the self-resonance frequency of the bridge structure. It can be seen that the reinforcement of anchor sprayed concrete can improve the overall rigidity of the structure, enhance the bending and torsion resistance of the structure, and improve the overall force characteristics of the bridge, which has high promotion and application value.

Combining fuzzy theory with neural network technology, a fuzzy neural network for safety evaluation of long-span suspension bridges is established. Seven evaluation indicators of long-span suspension bridges were determined, and the network was trained through sample learning, so that the network could acquire the empirical knowledge and intuitive thinking of bridge experts. The trained network was used for the safety assessment of Yichang Yangtze River Bridge and compared with the evaluation results of the Code for Maintenance of Highway Bridges and Culverts. The results show that the evaluation of long-span suspension bridges by fuzzy neural network is an objective and feasible evaluation method.

Railway traffic is a strip of buildings, its impact on the natural environment along the line is very complex, according to this feature, in the evaluation of the environmental impact of the railway, the "goal-indicator hierarchy" model is adopted, the analytic hierarchy method (AHP) is used, qualitative and quantitative indicators are combined, some important individual indicators are screened out and their weights are determined, and then the elimination and selection transformation method (ELECTREII.) is used to establish four matrices of priority, inferiority, ideality and proportion of inferior indicators. Finally, according to the determined threshold value and the drawn priority map, the schemes are compared and sorted until the optimal scheme is selected. An example is given at the end of the article for verification.

Anaerobic expansion granular sludge bed (EGSB) was used to treat glucose wastewater to study the effect of influent COD concentration on sludge granulation. The experimental results show that as the COD concentration of the influent water increases from 2 000 mg/L to 10 000 mg/L, the amount of nutrients entering the particles during mass transfer gradually increases, which promotes the granulation of sludge and increases the particle diameter. The drastic change of the influent concentration has a great impact on the reactor, causing excessive bacterial growth, loose sludge structure, decreased sedimentation performance, and reduced COD removal rate and gas production rate.

By introducing virtual branches and virtual nodes, a virtual port with simulated parameter asymmetry is established, and the parameter asymmetric power grid is decomposed into a symmetric network part and an asymmetric network part with simulated parameter asymmetry with the virtual port as the boundary. According to the basic principle of the compensation method, the injection current from the virtual port to the symmetric network is used as the compensation current to convert the parameter asymmetric power grid into a symmetrical power grid. After converting the asymmetric power grid into a symmetric power grid, various fault calculation methods based on symmetric component method can be used to calculate the fault of the power grid. Finally, an asymmetric system short-circuit fault is taken as an example to calculate, and the results prove that the algorithm is effective.

LCC series parallel resonant conversion circuit and Buck-Boost active power factor correction circuit composed of single-tube fluorescent lamp single-stage electronic ballast, because the switching device not only has to withstand the maximum voltage of Buck-Boost active power factor correction and LCC series-parallel resonant conversion circuit, but also load input and output current, requires a trigger circuit with good performance. In this study, the diode embedding method was used to make the trigger signal cross zero, and a trigger circuit with fast rising edge, falling edge and zero crossing characteristics was obtained. The electronic ballast using this trigger circuit can reduce the turn-on and turn-off time of the switching device, reduce the switching loss, and the life of the switching device is longer, the efficiency reaches 91%, and the power factor is greater than 0.99.

In order to provide a more rigorous theoretical basis for the study of the damping characteristics of static reactive power compensator (SVC), an intuitive linearization model (extended model) of stand-alone svc-infinity system considering the damping winding of generators is established, and the characteristic roots of the system are calculated for different situations, and the relevant factors affecting the magnitude of SVC damping are discussed. The results show that when SVC has damping control, it can provide positive damping to the power system. When SVC only has voltage control, it has little effect on system damping; When SVC has both voltage and damping control, increasing the voltage control gain will weaken the role of damping control; From the perspective of improving system damping, the best installation location for SVC is near the midpoint of the transmission line.

Aiming at the current situation and existing problems of billet heating furnace temperature control, a humanoid intelligent control strategy for furnace temperature is established according to the principle of humanoid intelligent control. The comparison and simulation experiment between the humanoid intelligent control algorithm and the conventional PID control algorithm is carried out by using MATLAB simulation software, and the results show that the humanoid intelligent control strategy has better control effect and stronger adaptability in furnace temperature control.

Firstly, the importance of database in software system development is analyzed, the gap between domestic data and foreign large databases is pointed out, and SQL Server 2000 and domestic databases are mainly compared and analyzed from several aspects such as data types, variable declarations and assignments, stored procedure definitions, executions and some SQL statements, with SQL Server 2000 and domestic databases - Kingbase ES3.1. Openbase et al. propose solutions to the problem of data portability between them.

Na2SO4·0.5H2O2· Thermal decomposition kinetics of H2O in nitrogen, determination of Na2SO4·0.5H2O2· TG-DTG and TG-DSC curves for H2O decomposition. At 8.0 K·min-1, 6.1 K·min-1, 4.1 K·min-1 and 2.0 K·min-14 heating rates, Na2SO4·0.5H2O2· The thermal decomposition of H2O is a simple one-step reaction with a thermal decomposition temperature of 339.5 K. Multiple nonlinear regression was used to control Na2SO4·0.5H2O2· The thermal decomposition kinetic model of H2O in nitrogen was screened, and the main curve method was used to identify the decomposition model. Na2SO4·0.5H2O2· The thermal decomposition process of H2O is controlled by the three-dimensional phase interface, and the decomposition mechanism is R3 mechanism.Na2SO4·0.5H2O2· The thermal decomposition activation energy of H2O was 70.83 KJ·mol-1, which refers to the pre-factor 1.96×103.

Based on the establishment of the ideal tracking model of vehicle turning, ∞a new method for active control of the front and rear wheel angles of four-wheel steering 4WS vehicles based on H-∞ model tracking technology is proposed, and the designed controller is simulated and compared. Through simulation analysis, it is theoretically verified that the controller designed based on H∞ tracking control theory can be applied to the four-wheel steering system of automobiles, which can follow the ideal vehicle steering model well and improve the active safety of vehicles.

Starting from the actual structural characteristics and specific working characteristics of the disc spring, the static stiffness test of the combined disc spring is carried out, and the nonlinear explicit algorithm of the finite element software ANSYS/LS-DYNA is used to calculate the continuous loading and load-unloading process of the stacked disc spring, and the load displacement relationship curve of the disc spring is obtained. Comparing the results and experimental values with the results of the traditional calculation method Almen-Laszlo formula, it can be seen that the results calculated by this method are basically consistent with the experimental values and are more accurate than the Almen-Laszlo formula. This provides an easy and correct way to select combination disc springs in engineering applications.

The protection of historical and cultural cities and the sustainable development of historical resources are issues of general concern. In view of the current situation of Dengfeng, this paper discusses how to integrate and continue the historical accumulation of urban material culture and spiritual culture from the perspective of the dual protection of urban material culture and spiritual culture, and do a good job in the protection of Dengfeng City. Through the establishment of protected areas and protected areas, the scattered cultural relics and monuments are integrated to enhance the influence of cultural relics and monuments in the overall landscape structure of the city. At the same time, combined with the protection area set up to match the traditional characteristic living space. In order to jointly strengthen the famous city style with the city as the core and the mountain city reflecting each other, so as to continue the historical context and highlight the urban culture.