1999 volumne 20 Issue 03

WANG Fuan; Ma Jinxing; Yang Yanfeng; etc
Abstract:
The hydrophobic constant is a lipophilic parameter of organic pollutants, which is an important quality that determines the transfer, distribution, absorption and infiltration and elimination of organic molecules in the environment, and is an important parameter for environmental science research and environmental protection evaluation. The hydrophobic constants of 6 alkylbenzenes and 7 aromatic amines in typical aromatic compounds at a temperature of 25~60 °C were determined by high performance liquid chromatography. According to the phase equilibrium theory of chemical thermodynamics, the thermodynamic relationship of hydrophobic constant with temperature was proposed, and the interphase transfer enthalpy△H and interphase transfer entropy △S were determined by experimental data. The temperature effect coefficient of the hydrophobic constant is discussed, which has the same order of magnitude as the literature value.


Yang Lingxia; Wu Jianping
Abstract:
According to the flow characteristics of the bottom water flow when the water level of the impedance pressure regulating chamber fluctuates, the change law of impedance loss under small fluctuations is analyzed, and it is considered that it is more reasonable to consider the impedance effect in proportion to the impedance loss and the first square of the velocity. After introducing it into the basic equation for stability analysis, the stability condition and critical stability section calculation formula of the water level of the impedance pressure regulating chamber under small fluctuations are derived. The results show that selecting an appropriate impedance type can help to improve the stability of small fluctuations in the water level of the pressure regulating chamber, and the critical stability section of the corresponding pressure regulating chamber will be smaller than that of Thoma.

Ren Baozeng; LIU Jianhua; Yang Yanfeng; etc
Abstract:
The hydrophobic constant is a lipophilic parameter of organic pollutants and an important parameter of environmental science research and environmental protection evaluation. On the basis of the previous research work, a relatively simple and practical new model for predicting/calculating the hydrophobic constant of organic compounds was established. Using the stepwise regression optimization algorithm, the hydrophobic constant experimental data of 203 compounds were recognized as relatively accurate, and the contributions and parameter values of 49 groups were determined. According to the new hydrophobic constant contribution model, the hydrophobic constants of 203 compounds were calculated, which were compared with the experimental values, all within the general experimental error range, which proved that the proposed new group contribution model was feasible to predict/estimate the hydrophobic constants of organic compounds.


WANG Wenyi; Zhang Xingjin; Zhang Ying
Abstract:
There is a class of grammars that accept the same language but cannot be recognized by operator-first analysis algorithms. An improved method is proposed to address the cause of the problem, which requires limiting the order of generators in grammar, that is, in addition to satisfying the established conditions of the arithmetic grammar, the grammar variables on the left part of each generator in the grammar must be distinguishable.


Wu Zhenqing; Zhang Liyan
Abstract:
The design method and principle of box exciter structural components (including bearing device, eccentric block structure and exciter seat structure) for inertial vibration equipment are introduced, the bearings used in the exciter are ordinary spherical roller bearings with large clearance, the outer ring tolerance of the bearing adopts P or N class fit with large interference amount, and the inner ring adopts H class fit. The bearing lubrication adopts lithium-based grease lubricant, and the seal adopts labyrinth, felt ring and lip sealing ring. There are three ways to adjust the excitation force, namely adjusting the weight of the eccentric block, the size of the eccentricity, and adjusting the weight and eccentricity of the eccentric block at the same time. The synchronization of dual-axis exciter generally adopts self-synchronization. The exciter designed according to this has a good effect after field use.

Liu Baochen; In the kingdom; Shen Changyu; etc
Abstract:
In the current engineering practice, the calculation method based on the average shrinkage rate is generally adopted for the calculation of the working size of the molded parts. This method deals with special cases, such as the shrinkage of materials and the manufacturing error of the mold in the limit state, so the original calculation formula is modified based on the average shrinkage calculation method and considering various factors in the limit state. Due to the complex structure of injection molded parts and the huge number of mold molded parts, the feature modeling technology is adopted, AutoCAD is used as the platform, and the method of combining Geometry/Feature is adopted to establish the characteristic information model of injection molded parts, which realizes the automatic conversion from the size of the injection molded parts to the working size of the molded parts.

WANG Dongyun; Guo Jifeng
Abstract:
The structure of intelligent processing unit in intelligent manufacturing system is proposed, and a neural network model of intelligent processing unit scheduling is established, which is a scheduling method integrating flexible manufacturing system (FMS) parts processing scheduling and flexible assembly system (FAS) product assembly planning. Simulation results show that this scheduling method is highly flexible and intelligent. Since the intelligent processing unit is an important intelligent node of the intelligent manufacturing system (IMS), in-depth research on its important component, the intelligent scheduling system, can improve the intelligence level of the intelligent processing unit.

Wu Kan; ZHANG Guangyu; CHEN Jingbo; etc
Abstract:
In order to predict the temperature distribution of the cavity surface of the injection mold under the given cooling channel distribution, the temperature analysis of the injection mold is carried out by the boundary element method. For the temperature field problem of injection mold, the boundary element method has the advantages of small data preparation, small calculation amount and high precision. However, since the cavity inside the injection mold is a slit and the length of the cooling hole is much larger than its diameter, the ordinary boundary element method cannot be calculated. According to the structural characteristics of the injection mold, the boundary integral equation suitable for the cooling analysis of the injection mold is derived, and the boundary element calculation method of the three-dimensional temperature field of the mold is given. Practice shows that this software has a good guiding effect on the analysis and design of injection mold cooling system.

Xie Wei; GAO Danying; Zhang Jianwei
Abstract:
The creep and shrinkage of concrete are the main influencing factors for the expansion of crack width of concrete structures under long-term loading. Due to the influence of environmental conditions, it has a large uncertainty in hydraulic structures, and there is no unified understanding and reasonable consideration method for the reliability of hydraulic concrete structural components. In order to correctly analyze and calculate the reliability of crack limitation of hydraulic structures under long-term loading, the influence of concrete shrinkage and creep variation on the cross-section indeterminacy of long-term load statistical uncertain members is discussed from many aspects, and the reliability analysis is carried out by using the normal service limit state "resistance-load effect conversion model". The results show that the reliability of cracking limitation of hydraulic structures under long-term loading is higher than that of general building structures. The reliability principle of the crack calculation formula of hydraulic concrete structural members is different

ZHANG Caiyun; Teng Wenrui; Zhou Zhi’an
Abstract:
From the perspective of engineering application, the sealing capacity of screw seals with different structural types and different groove shapes is theoretically discussed, and a calculation formula for spiral sealing liquid with good practicality is proposed. The analysis shows that under the same sealing conditions, the screw sleeve screw seal can not only obtain the same sealing capacity as the screw screw seal, but also improve the sealing effect. In addition, the sealing capacity of different groove spiral seals is different, and the sealing capacity of triangular groove spiral seals is larger than that of rectangular groove spiral seals, and the results obtained can be used as a reference for the design and selection of spiral sealing devices.

Yuan Qun; LI Bin; Geng Ye; etc
Abstract:
Pile foundation is widely used in engineering due to its advantages of high bearing capacity and good seismic performance, but at the same time, as a hidden project, the construction quality of pile foundation is difficult to control well, and engineering accidents caused by poor quality of pile foundation occur from time to time. Therefore, improving the level of pile foundation detection and analysis and identifying the defects in the pile is the premise of engineering safety and durability. In the existing ultrasonic pile analysis methods, the influence of different degrees of defects on ultrasonic sound velocity, frequency and amplitude has not been fully considered, and the corresponding methods for judging defects are relatively general. In view of this, the confidence intervals of the expectation and variance of ultrasonic sound velocity, frequency and amplitude are obtained by using the sampling distribution theorem, and on this basis, the membership functions of "good", "-general" and "poor" of ultrasonic quantity are given, and the ultrasonic detection pile is tested by the method of fuzzy comprehensive evaluation


Lu Yueli; CHEN Jiangyi; ZHANG Mingcheng; etc
Abstract:
A number of analyses and designs were carried out for the class II. six-pole mechanism in the bull head planer. The mechanism design scheme with the maximum pressure angle of the mechanism as the minimum value was determined; The motion analysis of the mechanism was carried out by the vector equation analysis method. According to the requirements of the working speed of the planer during planing processing, a mathematical model of the optimization design with the smoothness of the working speed of the planer as the objective function is established, and the optimization design is carried out by the composite shape method. The results of the example calculation show that the speed and smoothness of the planer in the working stroke of the optimized design of the class II. six-bar mechanism are significantly improved, which provides an effective design method for improving the working quality of the class II. six-bar mechanism in the bullhead planer, and this method also provides a theoretical basis for the optimization design of other reciprocating motion mechanisms.

Establishment of the company.
Abstract:
The structural feature theorem for deriving the structural characteristics of the original function from the structural characteristics of the derivative and the function is studied, and some corrections and generalizations are made to obtain the structural characteristics of the function itself and its derivatives. It is not only possible to infer the structure of the original function, but also to infer the tighter results of the structure of its higher-order derivative, so as to realize the unity of the inverse operation of the original function and the higher-order derivative on such functions.


Lu Hongxia; ZHANG Rui; Zheng Yingzi; etc
Abstract:
The reasons for the difference in recovery time between domestic and Japanese PTCR (thermistor) components as refrigerator compression starters were analyzed. In the experiment, TiO2 of Japanese rutile structure and domestic anatase structure were taken as raw materials, and PTCR samples were prepared by reacting with the same domestic BaCO3 powder and using the same electronic ceramic sintering process. Analyzing the resistance-temperature characteristic curve of the starting element, it was found that the temperature coefficient αT of the domestic PTCR element at high temperature was lower than that of the Nissan sample, and the longer recovery time of the domestic starter was due to the fact that the main raw material TiO2 for the preparation of the domestic sample was anatase structure, while the Nissan sample was rutile structure. The crystal structure of TiO2 powder has a certain effect on the resistance temperature coefficient of BaTiO3-based PTCR materials.

Wang Zhixiu; LI Feng; Zhang Yanxin
Abstract:
In order to make the modeling of the after-effect excitation step sequence more effective and concise, based on the general GM(1,1) model modeling method, the recursive method is used to determine the step point of the post-excitation step data sequence and its subsequent points, and the gray system prediction IGM (1,1) model of the after-effect excitation step data sequence is established. It has been verified that the fitting accuracy of this method is high, and the parameter estimation is simple, which is convenient and practical, and can replace the modeling method of post-excitation step data series in the above literature. Finally, applying this method, a national urban residential market demand model is established, and the market is predicted and analyzed.


WEI Xing; peak; LIU Lixin; etc
Abstract:
A new structural system in which a certain number of reinforced concrete shear walls are set along the height of the house in the structural system of multi-storey masonry houses is proposed. The shear wall can improve the lateral force strength and ductility of masonry houses, and broaden the application range of masonry houses in seismic areas. Through theoretical derivation, the reference formula for seismic verification of this structural system is given, and corresponding design suggestions are proposed. The analysis results show that compared with ordinary masonry houses, masonry houses with reinforced concrete shear walls have better seismic performance and deformation ability.


JIANG Tao; SUN Limin; Liu Kai

Abstract:
For the cycloidal wheel whose tooth shape has been determined, the correction method and correction amount of cycloidal wheel are optimized and analyzed by the improved composite shape method when the correction method and correction amount are unknown. At the same time, the simple "equidistance + distance" correction method of the process is used to replace the more complex angle correction method of the process, and the method is used to calculate the amount of equidistance and distance correction quickly, and the work efficiency is significantly improved compared with the traditional calculation method. The calculation results show that among the various correction methods of cycloid gear tooth shape, the correction method of "positive equidistance + negative shift distance" is the ideal correction method for the tooth shape of cycloidal wheel. This correction method has an ideal tooth shape, simple processing technology, and has certain promotion and use value in design and manufacturing.

Lu Shikui; WANG Li; Yu Weidong
Abstract:
Based on fuzzy mathematics, the comprehensive performance and economic benefits of air conditioning cold source equipment are comprehensively considered, and a secondary comprehensive evaluation mathematical model of refrigerator is established. The model divides the 9 factors in the factor set into 3 subsets U1, U2 and U3 according to the initial investment, operating cost and safe and environmentally friendly transportation, and then obtains its single-factor evaluation matrix R1, R2 and R3 according to the first-level evaluation, gives the weight distribution of the 3 subsets U1, U2 and U3, conducts the second-level comprehensive evaluation, obtains the best equipment, and gives application examples, and the case calculation shows that the theoretical results are completely consistent with the actual results.


Chen Yongxiao; WANG Yuhong; Duan Yintian; etc
Abstract:
When using the data control DC data binding control in VB to access the database, due to the limitation of its own small number of navigation buttons and single function, it can only browse the database simply, but cannot flexibly insert or delete data. In the development of the actual database application system, the original navigation button can be masked, the new navigation button can be added, and the new program code can be written for the newly added button. The database application system developed by this method has the characteristics of perfect function and simple operation, which can further expand the application range of DC.


CHEN Jianmei; Zhou Shiguo; Zhang Bin
Abstract:
In order to scientifically predict the economic indicators that enterprises are concerned about, so as to make correct decision-making plans for the future behavior of enterprises, it is necessary to use appropriate mathematical models and methods to quantitatively study the economic activities of enterprises. Based on the complex, changeable and many random factors of economic activities, the corresponding Markov chain model is established for two common economic problems, and the relevant theory of Markov chain is applied to skillfully construct the transfer probability matrix, and the problem can be solved quickly through simple matrix operations. Examples show that the Markov chain model and method are feasible and practical in the analysis of enterprise economic activities, and can be widely used to solve common forecasting and decision-making problems in enterprises.

YANG Manxiang.
Abstract:
According to the principle of rotating paraboloid, the solar medical device concentrating surface is designed for human medical treatment and health care. The basic equations for the design of concentrated surfaces are the parabolic equation and the rotating parabolic equation. The calculation content includes: each representative point and representative point vector calculation; Calculation of relevant angles; Theoretical thickness calculation of frame; Calculation of opening area. Basic machining data is provided for the manufacturing process through calculation.


SUN Lizhen; LI Guimei; Chen Zhen
Abstract:
Firstly, the seismic damage of the brick-concrete structure is analyzed, and the external cause of the failure of the masonry structure under the action of strong earthquake is ground motion, and the internal cause is the structural characteristics. Seismic structural measures for multi-layer brick-concrete structures are proposed, and the structural measures stipulated in the specification are all to ensure the integrity of the house and increase the ductility. In the seismic test of multi-storey masonry houses, it is pointed out that the essence of seismic verification of multi-layer brick-concrete structure is to review the horizontal shear strength of the wall. The seismic measures taken by the building, including the seismic isolation and damping of the building structure, the construction quality and the problems existing in the current construction of multi-storey brick houses, are discussed, which are of great significance to the seismic design of multi-storey masonry houses.

Copyright © 2023 Editorial Board of Journal of Zhengzhou University (Engineering Science)