1999 volumne 20 Issue 04
[1-2]
Abstract:
Liu Guo, Wang Zhihong, Luo Tingliang, etc
Abstract: The effects of preparation conditions of catalysts, selection of co-catalysts and selection of additives on the activity of catalysts are reviewed. It is pointed out that adding inorganic salts and water is beneficial to improve the selectivity of cyclohexene. The effects of reaction temperature, stirring speed and hydrogen pressure were discussed. The optimum conditions were as follows: temperature 360-460k, pressure 4.0-5.0 MPa, stirring speed 1500r/min. The reaction mechanism and the initial kinetic equation of partial hydrogenation of benzene to cyclohexene were discussed, and the activity of the precipitated ruthenium black catalyst was evaluated. The conversion of benzene was 96.47% at 413k and 5.0 MPa, the selectivity of cyclohexene is 50.01% , and its catalytic activity and selectivity can meet the requirements of industrialization.

Wang Fuming,Feng Hongjian, Zhou Hongjun
Abstract:

Aiming at the complex finite element method calculation of arch dam static analysis and the shortcomings of low accuracy in solving the dam type optimization problem, a spline semi-analytical method for the static analysis of thin arch dam is proposed based on shell theory and energy principle. It absorbs the general advantages of the spline function method, avoids the cumbersome calculation in the finite element method, and gives calculation examples that meet the accuracy requirements, and compares the results with the finite element method and the arch beam modal method.
LIU Lixin, Xie Lili

Abstract:
According to the current requirements of China to appropriately improve the reliability of building structures, the reliability level of the original < masonry structure design code >GBJ3-73 and the current < masonry structure design code > GBJ3-88 are analyzed, several reliability level adjustment schemes and the increase of material usage are compared in detail, and suggestions for adjusting the reliability level of masonry structure design are put forward, which can be used for reference when > revision of < masonry structure design code.

Zhang Guosheng; SUN Yufeng; LIU Xiaofang; etc

Abstract:
Ni23 3Zr6 7Al64Cu2 3Ce3.7 (atomic fraction) amorphous catalytic alloy was prepared by rapid solidification technology, activated by alkali washing and pumping Al, and a large specific surface area Ni-based amorphous alloy catalyst was prepared, and then its catalytic performance was tested on benzene hydrogenation. The results showed that the specific activity of this new catalytic material was 37.5% higher than that of conventional Raney Ni catalyst. The reaction kinetic analysis showed that the reaction sequence was basically one stage for hydrogen, and the reaction activation energy was about 31.2 kJ/mol, which was lower than that of conventional Raney Ni catalyst. Finally, the kinetic equation for benzene hydrogenation reaction is derived.


LIU Xintian; LI Yonggang; Zhou Xinping
Abstract:
According to the basic principle of die casting mold gate calculation, the calculation formula of the cross-sectional area of the inner gate and the flow velocity of molten metal in the inner gate is given. Using the heat transfer theory, the cavity filling time calculation formulas are derived from the hypothetical flat castings, which are important theoretical basis for the flow simulation and temperature crossing field simulation of the die casting process, and the main influencing factors for determining the cross-sectional area of the inner gate are preliminarily analyzed

ZHANG Qiming; Han Juhong; Li Chunyue

Abstract:
Using ultrasonic testing technology, the mechanical properties of 8 groups of 48 ordinary concrete and steel fiber concrete specimens were tested. Through the test of the occurrence and development of cracks in the specimen and the failure process of the specimen, various acoustic parameters of ultrasonic propagation in ordinary concrete and steel fiber concrete were obtained, and the propagation time and first wave amplitude attenuation of ultrasonic waves through the concrete specimen were obtained, and the influence of concrete strength and steel fiber content on acoustic parameters was analyzed and discussed, and the mechanical properties of ordinary concrete and steel fiber concrete were comprehensively analyzed on this basis. The results show that the mechanical properties of steel fiber concrete such as crack resistance and tensile resistance are significantly better than ordinary concrete

Lai Yongxing; Establishment of a society; Zhang Kan

Abstract:
The inlet tower of a reservoir flood discharge project is a large-volume concrete structure, with complex body size, force and boundary conditions, and the lower part of the tower body has a large orifice flood discharge channel, and the bedrock is soft. According to the structural characteristics of the inlet tower, the finite element discretization of the inlet tower is carried out by using the space block unit, the strength and deformation of the inlet tower under seven working conditions are calculated, and the stress contour diagrams of several typical cross-sections are given, and some useful conclusions can be used as the design basis.

ZHANG Congliang; Tang Yanli; Li Xuemeng

Abstract:
The research status of the alkylation reaction between isobutane and butene is expounded, the main characteristics and advantages and disadvantages of some solid catalysts and liquid catalysts are discussed, the development status of the alkylation reaction between isobutane and butene under supercritical conditions is introduced, and the development prospect of the alkylation reaction between isobutane and butene under supercritical conditions is predicted. The results show that the large-pore molecular sieve with less B acid, more L acid and large specific surface area is expected to be an ideal catalyst for supercritical alkylation.

Yang Weizhong; WANG Li; ZHANG Shihong; etc
Abstract:
The shortcomings of the calculation formula for the local compressive bearing capacity of masonry under the pad were analyzed in the current masonry structure design code, and the stress-strain relationship of the existing compressed masonry was revised based on the characteristics of eccentric compression masonry, and the stress-strain relationship when the masonry was eccentrily compressed. Using the flat section assumption and cross-section balance member, the calculation formula of local compressive bearing capacity of masonry under rigid pad is derived, which has the characteristics of simple calculation and clear concept, and can be coordinated with the calculation of local compressive bearing capacity of beam end masonry, and the calculation results are in good agreement with the test results. The results also have a reference effect on the analysis of the compressive bearing capacity of masonry, which can be used as a reference for the revision of masonry structure design specifications.


Yang Wanhui; WANG Yong; LIU Wei; etc
Abstract:
According to the actual needs of the power department for the technical training of substation operators, a general system for substation simulation training was developed. The system uses multimedia technology to realize the full soft simulation of the electrical main wiring simulation panel and protection screen of the substation, which is low cost, easy to expand, and more flexible training means. The operation results show that the system has strong versatility and maintainability, and provides a good software development platform for the promotion of substation computer simulation technology.


LI Huizhi.
Abstract:
Through the model wind tunnel test with a scale ratio of 1:300, the wind environment around a high-rise building before and after the completion of 16 incoming winds was studied, and combined with the local meteorological wind speed data, the comfort of pedestrian height wind environment in 26 positions around the building was analyzed under three conditions: sitting, standing and walking. The results show that the wind environment around the building basically meets the comfort conditions. Finally, suggestions and measures to improve the local wind environment are put forward for individual areas.


WANG Xia; Zhao Lingling; Zhao Wenlian; etc
Abstract:
In order to quickly solve the large quasi-block three-diagonal equation system, a fast algorithm is proposed according to the structural characteristics and communication characteristics of the hypercube multiprocessor system, combined with the characteristics of the solution problem itself, and the running time complexity of the algorithm is analyzed. Numerical experiments were carried out in parallel virtual environment (PVM) to find the running time and speedup ratio on multiple workstations. The results of the shared memory multiprocessor are compared, which proves that the algorithm runs faster on the hypercube.


LI Wen; LIU Hongmin; Zhang Xia
Abstract:
In the study of the relationship between structure and activity of para-substituted phenol glucosides, compounds that strongly inhibit telomerase activity were found. The infrared spectral absorption of such compounds measured by the West German PE-1710 infrared spectrometer showed that the absorption of C-O bonds, glucose pyran rings and ben rings showed obvious infrared spectral characteristics, that is, with the regular change of electronegativity of the compounds, the infrared spectral absorption also showed regular changes. In addition, the relationship between C1-H NMR displacement and glucose pyran ring infrared absorption peak is further discussed. No similar studies have been reported to date.


Xin Xiaonan; Jia Life
Abstract:
Since the output voltage of the resolver is independent of the speed and there are no brushes and slip rings, it is suitable for the excitation system of synchronous motors with thyristor speed regulation. Using the methods of circuit analysis and magnetic circuit analysis, the structural characteristics of the resolver are analyzed, and it is derived that when the angle between the stator core and the rotor core surface to the shaft core meets certain conditions, the magnetic resistance of the resolver can be guaranteed to remain unchanged when rotating. When the air gap ratio k=2, the three-phase voltage is symmetrical.

Tang Wenbo; Wu Zhenqing; Zheng Yingzi; etc
Abstract:
Arc spraying technology is widely used in the field of surface engineering, and whether it can be isokinetic synchronous wire feeding is its technical key. A wire feeding motor speed regulation system is proposed, on the basis of analyzing the arc spraying principle, by adopting the PID automatic adjustment system by PWM speed regulation and photoelectric speed measurement, the constant velocity synchronous wire feeding is realized, and the wire feeding speed can be digitally indicated and pre-adjusted. This circuit has low cost and high cost performance, which is a circuit worth promoting.


HUANG Qiang; LI Nan; Jiang Yuanli
Abstract:
High-purity pectin is obtained through a series of treatment processes such as pretreatment, hydrolysis, deesterification conversion, decolorization, concentration and drying of apples and their skin residues. Advanced immobilized enzyme reaction technology was used to use the catalytic effect of α-amylase to perform hypoesterification treatment of the obtained pectin; The hydrolyzed product was separated from the substrate by ultrafiltration to obtain D-galacturonic acid with high purity and low esterification. This product has certain practical value in tobacco conservation.

Wang Jianfeng; WU Feng; Wang Guoqing
Abstract:
Find an optimal working fluid pair to improve cooling capacity and cooling efficiency. The basic theory of adsorption equilibrium was applied to determine the properties of several possible adsorption refrigeration new working fluid pairs of zeolite-ethanol, zeolite-ethylene glycol and zeolite-isopropanol. The results show that the developed zeolite-ethanol working fluid pair is a good substitute for zeolite-water and activated carbon-methanol working fluid pairs, and its refrigeration capacity can be increased by 74.93% compared with the zeolite-hydroworking fluid pair, which is a working fluid pair with practical prospects.


ZHANG Xiang; Yang Lin; Lou Quanling
Abstract:
In order to find the regularity of the effect of solvent properties on the stability of crown ether coordination compounds, the stability constant logK of the complex formed by crown ether 15C5 with metal cations such as Pb2+, Co2+, Ni2+, Cu2+ and other metal cations in the mixed solvent of methanol (MeOH) and acetonitrile (MeCN), ethanol (EtOH) and acetonitrile (MeCN) was further determined, and the regularity of the influence of solvent properties on the stability of complexes was further studied. The relationship between the stability constant logK of the complex and the molar fraction x of acetonitrile in the mixed solvent was obtained


Liu Jiayong; Wu Mingjian; Shen Guopeng; etc
Abstract:
The extraction method of natural β-carotene was studied.β-carotene is the most important provitamin A, and vitamin A has an extremely important role in human vision and a number of physiological functions, in order to avoid the shortcomings of more side effects of products obtained by chemical synthesis on the human body, and in view of the limitations of extracting natural products from salt algae, corn gluten powder, a by-product of corn starch, is used as raw material, the appropriate extractant is selected, and natural β-carotene is extracted by extraction-chromatography to achieve higher yield. Compared with the saline algae method, this method has higher social and economic benefits.


Force application; ZHU Mingxia; Huang Zuyi
Abstract:
The general software of finite element structure analysis has been widely used in the analysis and calculation of mechanical products, and the model simplification, network segmentation and input of certain parameters of the research object are very critical when performing dynamic analysis calculation. This paper summarizes the experience in the calculation of engineering examples of various types of mechanical products, points out the problems that should be paid attention to when using general software for frequency solving, dynamic response analysis, stability analysis and contact stress analysis, and gives simplified methods for boundary elements and parameter input skills.


Su Hong; ZHAI Zhen; Tanaka
Abstract:
AutoCAD R14 software is used to develop an electrified railway drawing management system, which has the function of design and drawing of railway traction power supply system, and can realize the step-by-step reporting of drawings from power supply section, sub-bureau to road bureau. The method of customizing the AutoCAD R14 system menu as the user’s own menu, the design idea of the component library call module, the implementation process of the station column program, and the method of saving the disk using block operation are expounded, and the system is programmed in AutoLISP language. The trial operation shows that the system has strong reliability, simple operation and fast operation speed.

WANG Yong; ZHANG Lei; Standing Army; etc
Abstract:
Human resources are a special economic resource, is the dynamic production factor in the production process, it has a decisive impact on economic development, the quantity and quality of human resource factors, is the vitality and strong driving force of enterprise prosperity. Doing a good job in human resources forecasting can better explore the potential of enterprise human resources, control the cost of enterprise human resources from multiple angles, fully mobilize the enthusiasm, initiative and creativity of enterprise human resources, so as to improve the labor productivity of enterprises, and then achieve the business goals of enterprises. Therefore, several quantitative analysis methods of human resources forecast planning are discussed, namely time series model, regression model, econometric model, and state transition equation model. The relevant formulas are given and the credibility of these methods is compared. The results show that they


LI Yongfeng; CHEN Yiyi; XU Jun; etc
Abstract:
The nitrobenzene gas-phase hydrogenation reaction is controlled by the internal diffusion rate, so in order to effectively reduce the influence of internal diffusion, it is necessary to reaming the silica gel of the Cu/SiO2 catalyst used in the reaction. By adding sodium carbonate solution and ammonia aqueous solution to silica gel to reamb the pores, some rules of reaming were studied, and the Cu/SiO2 catalyst prepared by reaming silica gel was determined by copper content, pore volume, density and activity specific surface, so as to determine the optimal conditions for reaming treatment when preparing Cu/SiO2 catalyst: use sodium carbonate solution with a mass fraction of 0.67% as a pore reamer, reaming at 50 °C, and roasting at 500 °C for several hours.

Wang Peng; Wang Fuming; LI Qiang; etc
Abstract:
In order to improve the shortage of traditional pavement base materials, a new type of material with reasonable technology and good performance was sought for pavement base layer, and the 3001-day compressive strength of ISS, LE-6003 and LPC-7 liquid soil stabilizer stabilized soil was tested through indoor tests, and a comparative test of limestone soil was made. The results show that the addition of a small amount of lime can significantly improve the strength of liquid soil stabilizer, which has obvious significance for reducing the dose of lime, improving the strength of the base layer and reducing the thickness of the base layer. It provides a scientific basis for the promotion and application of liquid soil stabilizer.


ZHANG Dayong; LIU Lixin; Xie Lili
Abstract:
Due to the requirements of seismic design, many masonry walls are equipped with structural columns, which allow the height to thickness ratio limit to change, and the test algorithm needs to be corrected. According to the pressure bar stability theory, the difference between the allowable height to thickness ratio limit of the wall with and without structural column is analyzed, and the allowable height to thickness ratio limit of various types of walls considering the influence of structural column in the current masonry structure design code is calculated and compared, and it is pointed out that when the spacing of the structural column is within a certain range, the allowable height to thickness ratio limit of the wall can be increased by 10%~20%.


LIU Yingmei; Yang Wanhui; ZHANG Jian; etc
Abstract:
This method uses artificial neural network (ANN) to realize substation fault diagnosis, which makes full use of the strong learning ability and high fault tolerance of artificial neural network to realize the diagnosis of substation fault components. The simulation results show that this method can not only accurately diagnose the faulty components when the protection and switch operate correctly, but also effectively diagnose the faulty components when the protection or switch rejects the leapfrog fault.

Zheng Mingjie; LIU Jianwei; Shi Li; etc
Abstract:
Using the Client/Server mode, the scientific and technological achievements management system is established, which completes the form declaration, floppy disk declaration, and remote declaration of scientific and technological achievements, and realizes the functions of data addition, deletion, modification, query and so on; In terms of security management, multi-level operation permissions are set, different users are given corresponding permissions, and the highest permissions are set for some key operations; The functions, design and implementation of the system database and client application are expounded, and the system performance is optimized from both the application and the database. Finally, the connection method and implementation steps between the front-end application and the back-end server are given

ZHANG Liyang; Jiang Denggao; ZHOU Cairong; etc
Abstract:
In order to obtain accurate and complete solubility data of methyl hydroquinone, in order to prepare high-quality methyl hydroquinone, the solubility of methyl hydroquinone in solvents such as benzene, chloroform, water, ethanol and ether was determined, and the solubility equations of methyl hydroquinone in benzene and chloroform at different temperatures were given, and the conclusion that methyl hydroquinone was easily soluble in water, ethanol and ether was obtained, which provided a basis for liquid-solid equilibrium, crystallization process research and engineering design. In addition, rough estimates show that methyl hydroquinone forms a non-ideal solution with benzene and an ideal solution with chloroform.

ZHANG Xiuli; LIU Wufa; Berger Hou; etc
Abstract:
This paper analyzes the problems of traditional flat winding machines, and proposes a numerical control flat winding system based on IPC (Industrial Personal Computer). The numerical control system consists of industrial computer, servo control card, servo drive device, encoder, etc. to form a semi-closed-loop control circuit. The control software adopts C language programming, and realizes winding control by establishing a mathematical model of the motion trajectory of the flat winding machine. Experiments show that the numerical control system can improve the winding accuracy and work efficiency of the flat winding machine.


CHENG Tianbo; HOU Zhifeng; Guan Pinwu; etc
Abstract:
Starting from the basic principle of seismic design in China, the ductile design of reinforced concrete frame columns is expounded, and it is believed that the effect should be further increased to improve the reliability of structural design and ensure good bearing capacity and deformation capacity of the structure. At the same time, the degradation mechanism of shear strength in the plastic hinge area is analyzed, and suggestions for the calculation of shear bearing capacity and restraining stirrups are proposed for reference when the specification is revised.


GUO Linlin; ZHANG Xinyu; Yang Songhua
Abstract:
The approximate calculation of the abnormal integral of the singularity on the vertex of the rectangular domain and the optimization center numerical algorithm are given, which avoids a large number of repeated calculations of function values, uses the extrapolation method to reduce the number of iterations, and can reach the approximate value that meets the accuracy requirements as soon as possible, and the proposed optimized numerical algorithm is convenient for calculation on the computer.


Lei Mingqin; Zheng Guansheng
Abstract:
Since the operation of Luoyang Guxian Reservoir in February 1992, although it has exerted great benefits in flood control, water supply and power generation, it has caused unstable flow of downstream rivers after peak shaving operation, and the irrigation, power generation, water supply and aquatic products of downstream counties have caused great losses. The necessity and feasibility of building the Yumen River counter-regulation reservoir are analyzed from the aspects of geographical location, geological structure and economic benefits, which provides a technical basis for the early construction of the project to give full play to its huge economic benefits.

Shi Xiangyu; Ponjie
Abstract:
China is a big cotton producer, and most of the cotton stalks have not been further developed and utilized. In this experiment, cotton stalks were used as raw materials, decolorization activated carbon was prepared from cotton stalks by phosphoric acid method, and the process conditions such as carbonization and activation were studied, and the experimental results showed that the yield and decolorization performance of the product were stable, and the consumption of activator was small, which provided ideal experimental conditions for converting cotton stalks into activated carbon.


Wang Lixin; Ma Jianping
Abstract:
The EUCLID software system is applied to the production of glass shell, according to the production characteristics, how to use CAD system to establish glass shell mold database, use CAM to automatically generate data processing programs, and use CAE software to analyze the mold cavity cooling system and temperature field under high temperature forming state, so as to predict potential defects in the design and produce molds that meet industrial requirements. The practice has proved that the CAD/CAM system is practical and effective, while the CAE system software needs further research.

Jimbo; Ma Hanji
Abstract:
The purpose of treatment of bad foundation soil is to improve the bearing capacity of foundation soil. Taking the optimal selection of backfill land foundation treatment scheme of Longhu New Town villa as an example, the optimal decision-making method of enumeration method of bad foundation treatment scheme in actual engineering is introduced, and the deep mixing pile method is selected by comparing and optimizing the four schemes of ash soil squeezed pile method, CFG pile method, strong compaction method and deep mixing pile method. The treated foundation soil not only meets the design requirements such as bearing capacity, but also reduces the investment, which has certain reference value for similar projects.

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