The concept of the main vibration direction of rectangular plate vibration is proposed, and the vibration waveform of rectangular plate is unique in the main vibration direction, so that the unified vibration function expression of the four-sided supporting rectangular plate is established, and the frequency equation of the free vibration of the plate and the corresponding mode shape curve are derived, except for a pair of side simple branches, a pair of side fixed rectangular plates and three-sided simple branches, and one side fixed rectangular plate only occurs a pair of side simple branch directions of vibration in the main vibration direction, the rest of the plates have two main vibration directions.

High-performance computer technology is one of the important symbols to measure a country’s scientific and technological level and comprehensive national strength, and at present, some developed countries in the world are competing to invest huge amounts of money in its development and research. PC cluster computers are the cheapest high-performance computers. Some key technologies in the construction of clustered computer systems, such as scalability, availability, resource management, load balancing and parallel programming environment, are discussed, and an example of parallel programming based on MPI environment is given, and its practical significance in different fields is also proposed according to the characteristics of clustered systems.

A dynamic evaluation method for determining the buckling load of oil drilling derrick structure is proposed. The basic idea is: firstly, the eigenvalue equation of the derrick structure is used to establish the relationship between the basic natural frequency of the derrick structure and the vertical axial force it bears; Then, the basic natural frequency ω1i corresponding to the various levels of load Ni of the derrick structure is calculated or measured, and the change curve between the basic natural frequency ω21i of the derrick structure and the load Ni can be obtained, and the axial force corresponding to ω21i=0 is the buckling load of the derrick structure. The proposed method can be combined with the non-destructive test of derrick structure to determine the buckling load of derrick structure, which is a practical method for evaluating the bearing capacity of oil drilling derrick structure.

The electron effect between atoms or groups in organic molecules or intermediates, namely induction effect, conjugation effect, superconjugation effect, and spatial effect, was studied and analyzed, focusing on the stability of organic matter or intermediate, as well as the reaction orientation of electrophilic, nucleophilic and free radicals, and the results showed that the electron effect had an important impact on the stability and reactivity of organic matter or intermediate, and the spatial effect also had an important impact, and sometimes even the main influencing factor.

During the reaction of acetylene and acetic acid to synthesize vinyl acetate, the inactivation of the catalyst is caused by the sublimation of zinc acetate Zn (OAc)2 in the catalyst from the surface of activated carbon into the gas phase and the blockage of the condensate in the micropores. The sublimation mechanism is that the reaction product reacts with Zn (OAc)2 to form volatile complexes, which are then sublimated into the gas phase. The total loss velocity can be described by LR=1-exp (-kvt), which is the application generalization of the sublimation velocity equation. where v is the velocity of the airflow, t is the reaction time, and k is the velocity constant.

The significance of the application of high-speed machining technology in mold manufacturing is described, and some core technologies necessary to achieve high-speed machining are described. By comparing with conventional EDM methods, the superior performance of high-speed machining and the requirements of high-speed machining for the spindle, tool and CAM software of machine tools are discussed, and it is pointed out that in the cavity mold manufacturing process, the choice of machining method mainly depends on the geometry of the cavity, the hardness of the material and the required process parameters, and finally the processing example shows that high-speed cutting is one of the development directions of modern mold processing.

Uneven thermal residual stress and its deformation are one of the common engineering problems in injection molding processing. The recursive formula obtained by applying the two-dimensional thermoviscous constitutive equation of thermally rheological simple materials numerically simulates the thermal residual stress and its warpage deformation in molding, and discusses the influence of temperature and pressure on the residual stress and deformation of injection molded parts by numerical experiments, and finds that uneven temperature change is the most important cause of warpage deformation of injection molded parts, and its influence is much greater than the effect of pressure, which is consistent with the conclusion of engineering experiments.

The Code for Anti-corrosion Design of Industrial Buildings stipulates the minimum thickness of the protective layer of stressed steel bars in concrete structures, and believes that for reinforced concrete structures that are exposed to weak corrosive media, with the decrease of the protective layer of steel bars, the durability of the structure will also decrease. According to this design requirement, a durability criterion based on concrete carbonization corrosion is proposed, the corresponding durability coefficient concept is defined, and an optimal maintenance strategy of concrete structure with "repairing the old as new" is established accordingly.

According to the basic assumption of the composite pipe, the stress state during the hydraulic expansion process of the composite pipe is analyzed. Using the elastoplastic theory, the stress-strain relationship between the inner pipe and the outer pipe of the composite pipe is discussed, and the deformation coordination conditions of the circumferential strain of the inner and outer pipes of the composite pipe are used to calculate the correlation formula of the residual contact pressure Pc* between the hydraulic expansion force Pi and the inner and outer pipes of the composite pipe, and the working pressure range of the hydroforming fluid pressure Pi under different conditions is obtained according to the different residual contact pressures during the forming process of the composite pipe.

By calculating the seepage field around the cement-soil retaining wall, the variation law of water pressure on the wall side was studied. The results show that the water pressure coefficient is not constant along the elevation, and is seriously affected by the distribution of soil layer on the wall side and its relative permeability, the permeability of the wall foundation soil and the buried depth of the impervious layer lying down. In general, the side pressure behind the wall when considering seepage is always less than the corresponding value when seepage is not considered, and when the passive earth pressure coefficient in front of the wall is small, the side pressure on this side when considering seepage is greater than the corresponding value when seepage is not considered, so this situation is conducive to the stability of the retaining wall.

Taking the locomotive as a whole system, 17 degrees of freedom are used to describe the spatial position of the locomotive in the transverse plane in general. Considering the elastic support of the suspension device of the first series and the damping characteristics of the shock absorber, the mechanical model of serpentine motion of the four-axis bogie vehicle was established, and the differential equations of motion were listed. The eigenvalues obtained by the variable step method are used to study the serpentine motion stability and the critical speed of the locomotive, and the conclusion is that increasing the lateral and longitudinal stiffness and damping of the wheelset can reduce the serpentine motion of the bogie and the car body. Reasonable optimization parameters were obtained, and improvement measures were proposed: the hydraulic shock absorber was changed to an electromagnetic hydraulic shock absorber or a serpentine shock absorber, and the original column spring was replaced by a cone spring.

The force analysis of the flat hinged arch bridge structure belongs to the boundary nonlinear mechanical problem, and the force analysis of some current methods is not clear, and the flat hinged arch bridge such as variable section and complex shape section cannot be calculated. In view of this situation, a new method for determining the resistance coefficient K of flat hinge section is proposed, an iterative algorithm for calculating the internal force of flat hinge arch bridge is established, and an example calculation is carried out, and the research results show that this method is applicable to arch bridge structures with arbitrary flat hinge and arbitrary shape cross-section.

Based on the existing experimental data, the creep analysis of high-rise and long-span civil buildings can only be carried out by referring to the creep coefficient method in bridge structure or the creep method in hydraulic structure. Starting from the definition of creep coefficient, the median integral theorem and superposition principle are used to derive and modify the expression of the increment of creep shrinkage strain at different times of loading age and starting age, compare the difference in efficiency and accuracy between the finite element method applying creep coefficient analysis of creep and the initial strain method applying creep analysis of creep, and suggest that the initial strain method of creep degree should be used from the perspective of conceptual design to estimate the impact of creep on high-rise and long-span civil buildings.

How to quantify the insensitivity of a statistical method to outliers has always been an important topic in robust statistical research. The sample collapse point of the test is the minimum proportion of outliers in the sample that can reverse the verdict. On the basis of studying relevant literature, the sample collapse point of the exponential distribution parameter maximum likelihood estimation test is calculated, and the asymptotic normality of the sample collapse point is analyzed, which provides a new way for the robustness of quantitative statistical methods.

The internal mechanism of hardware interrupt service implementation and the response performance of the system to interrupt signal of 32-bit Windows system are analyzed, and the influence of interrupt frequency, interrupt mode, scheduling mode and other factors on the real-time response performance of Windows hardware interrupt is discussed by comparing the interrupt delay obtained in various test environments. It is pointed out that in the case of unavoidable interrupt delay in 32-bit Windows system, the use of non-shared interrupt and appropriate scheduling methods can relatively reduce the interrupt delay and improve the real-time response performance of hardware interrupts.

According to the characteristics of this type of problem, it is generalized into "unconstrained scheme queuing problem" and "constrained scheme selection problem", and a approximation ideal solution ranking model and a multi-objective fuzzy integer programming model based on hierarchical analysis and entropy weight are proposed. Case studies show that it is necessary to divide the multi-objective decision-making problem of scheme selection into two steps, and multi-objective quantitative analysis of scheme optimization is the future development direction.

It is more difficult to arrange steel bars in a single section in a small section, and most foreign regulations use parallel reinforcement to solve it, but the influence of reinforcement on the bearing capacity after merging is not clearly stipulated, and the bearing capacity and stiffness of parallel reinforcement beams in China are less studied. Through the test of the bending bearing capacity of 10 reinforced beams and 3 control beams, the influence of the reinforcements on the bending bearing capacity of the beams was analyzed, and the test was loaded at three points, and the results showed that compared with the control beams, the bending bearing capacity of the reinforced beams was reduced, and the reduction was between 10%~15%, through statistical analysis, the recommended formula for the bending bearing capacity of the reinforced beam was given, and the reliability analysis of the suggested formula was carried out.

By analyzing the derivatives of a class of complex functions and their own structural characteristics, the first derivative of the class of functions and their own structural characteristics are obtained, and the original function of the class of functions and its higher-order derivatives can be quickly and accurately inferred without any analysis operation. The results show that the inverse operation of the higher-order derivative and the original function can be unified in this class of functions. The use of this result can bring a lot of simplification and convenience to the actual operation.

According to the characteristics of comprehensive utilization of reservoirs, from the perspective of making full use of water resources, an optimal scheduling model with the goal of minimizing the amount of abandoned water is established, and the variable step incremental dynamic programming method is used to solve this model. In the process of solving and seeking optimization, the optimal scheduling line of the previous research results is used as the initial strong state sequence, and it is iterated one by one until the optimal decision sequence and the optimal state sequence are approximated. Example calculations show that the established model is reasonable. This model not only seeks to minimize the amount of water discarded in the reservoir, but also increases the benefits of irrigation, power generation and water supply, and provides a basis for the optimal operation of the comprehensive utilization reservoir.

Using the reliability theory, according to the design specifications adopted by the existing brick masonry structure in China, the test model of seismic and non-seismic brick masonry wall was established, and the Monte-Carlo random simulation method was used to test and analyze these two types of models under the action of horizontal earthquake, and according to the statistical principle, the conclusion and cause of the failure part of the brick masonry structure wall mainly occurred in the corner of the wall opening, and the common working coefficient of constrained masonry was verified.

The production and molding process of zinc electrode and the inhibition of zinc dendrite additives were studied, and the influence of zinc electrode manufacturing process on the performance of the Zn-Ni battery and the effect of various additives were discussed. The results show that the colloidal membrane structure and additives on the surface of the zinc electrode can effectively prevent the generation of zinc dendrites, and the structure of lead dendrites designed in the zinc electrode can effectively reduce the gas precipitation during charging of zinc-nickel batteries, and the cyclic discharge performance is stable.

Introduce the process of wet acid delysis of copper oxide ore and co-production of copper sulfate and iron oxide. The process flow is to acid leach the copper ore powder, crystallize first, and then replace the copper sulfate mother liquor to remove impurities, and the iron salt in the impurity removal process is prepared to obtain iron oxide. The effects of reaction acid concentration, acid leaching time, liquid-solid ratio and roasting temperature on wet production were discussed, and the optimal process conditions were determined as follows: sulfuric acid concentration 20%, time 3 h, liquid-solid ratio 2.8∶1, temperature 580 °C. Experiments show that the copper sulfate and iron oxide co-produced by this process meet national standards and are feasible in industrial production.

Considering the limitations of the optimal design method in the field of mechanical design, combined with the uniform design technology and the optimization design idea, a method of optimal design is proposed. Compared with the general optimization design method, this method has the characteristics of simple programming and no strict requirements for the design model behavior, which is a supplement to the mechanical design method. Finally, the idea of using this method to prepare the calculation program and the specific calculation examples are given, and the results verify the feasibility of applying uniform design technology in mechanical design.

According to the basic equation of AC excitation generator with symmetrical rotor structure, combined with the characteristics of the excitation system of this type of motor and the characteristics of asynchronous operation, three adjustment quantities of the excitation system are comprehensively considered: frequency, amplitude and phase angle of the excitation voltage. The angle between the induced potential of rotor flux (current) in the stator winding and the stator voltage is defined as the work angle, and the work angle component and slip rate caused by the difference between the angular frequency of the rotor rotating magnetic field and the synchronous angle frequency are used as state variables, and the fourth-order simplified dynamic analysis model is derived. At the same time, the state equation of the AC excitation generator in the stand-alone infinity system is given, which provides a theoretical basis for the research of the stand-alone infinity system with alternating current.

According to the characteristics of single product structure, multiple production types, difficult production control and high energy consumption of electrolytic aluminum industry, the current enterprise resource planning (ERP) theory is used to give the ERP architecture diagram of electrolytic aluminum industry. The structure takes MRPII as the core, combined with Internet technology, and adds modules such as formula management, energy management, and electrolytic aluminum production computer management. The design ideas of defining process formulas, defining process processes, electrolytic aluminum process control, simulation, fault diagnosis and ERP and JIT management methods in these modules are briefly introduced, and the system has been implemented in Tian Yuan Aluminum Group with good results.

This paper describes the method of providing different service quality QoS in the integrated service network, and because network applications require different service quality, IETF proposes an integrated service model. Firstly, the three service levels and corresponding service quality of integrated services are described, and then the basic components of the integrated service implementation framework are analyzed: packet classification, scheduling, admission control, packet drop and reservation protocols, including the implementation mechanism of traffic control in routers, and finally the signaling protocol of integrated services, resource reservation protocol, and its support for integrated service QoS are discussed.

In order to recover and purify the benzoic acid in the oxidation residue of PTA, the solubility of benzoic acid in chloroform, N,N-dimethylformamide, N,N-dimethylacetamide and N-methylpyrrolidone was determined by synthesis by laser monitoring technology. In order to verify the reliability of the determination method, the solubility of benzoic acid in water and acetic acid was determined in advance, and the consistency was better than that of the existing literature data. The solubility model proposed by Apelblat et al. was used to correlate the experimental data, and the calculated solubility was in good agreement with the experimental value.

Aiming at the low accuracy and insufficient response lag of the traditional statistical theoretical line loss calculation method of distribution network, a method of real-time theoretical line loss calculation using real-time telemetry data stored every 5 minutes is introduced, and the model recognition technology is adopted for the model parameters during the implementation process. The practical application shows that this method can better estimate the operating state of the line or transformer on the line, so that the deviation of the calculation result is smaller and closer to the actual line loss rate.

In view of the current situation of the discharge of wastewater from aluminum industry in China, combined with the actual situation of large water consumption and large amount of wastewater discharged and heavy pollution in the production of alumina of China Great Wall Aluminum Company, the pollution of wastewater in the aluminum industry and its impact on production are comprehensively analyzed for many years, and the water resource problems that need to be solved urgently in the aluminum industry are studied, and specific measures for closed-circuit treatment are proposed one by one to reduce the amount of wastewater discharge, reduce pollution, and save primary water use, so as to realize the unity of environmental, economic and social benefits of the aluminum industry.

College campuses are being renovated and expanded for better development. In the reconstruction and expansion, the overall principle, the logo principle, and the economic principle should be followed. Through analysis, the reconstruction and expansion of university campuses can be divided into replacement mode, filling mode and expansion mode. These three models are analyzed and discussed.

It is pointed out that small and medium-sized civil buildings are the main components of urban architecture, constitute the basic environment of the city, and play an important role in the urban landscape. Call on architects to pay attention to the creation of small and medium-sized civil buildings and strive to create high-quality buildings; According to the characteristics of small and medium-sized civil buildings, three basic creative consciousnesses that should be emphasized in the creation are proposed: humanistic awareness, environmental awareness and characteristic awareness.